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<ol class="chapter"><li class="chapter-item expanded "><a href="The-Z-Shell-Manual.html"><strong aria-hidden="true">1.</strong> The Z Shell Manual</a></li><li class="chapter-item expanded "><a href="Introduction.html"><strong aria-hidden="true">2.</strong> Introduction</a></li><li class="chapter-item expanded "><a href="Roadmap.html"><strong aria-hidden="true">3.</strong> Roadmap</a></li><li class="chapter-item expanded "><a href="Invocation.html"><strong aria-hidden="true">4.</strong> Invocation</a></li><li class="chapter-item expanded "><a href="Files.html"><strong aria-hidden="true">5.</strong> Files</a></li><li class="chapter-item expanded "><a href="Shell-Grammar.html"><strong aria-hidden="true">6.</strong> Shell Grammar</a></li><li class="chapter-item expanded "><a href="Redirection.html"><strong aria-hidden="true">7.</strong> Redirection</a></li><li class="chapter-item expanded "><a href="Command-Execution.html"><strong aria-hidden="true">8.</strong> Command Execution</a></li><li class="chapter-item expanded "><a href="Functions.html"><strong aria-hidden="true">9.</strong> Functions</a></li><li class="chapter-item expanded "><a href="Jobs-_0026-Signals.html"><strong aria-hidden="true">10.</strong> Jobs &amp; Signals</a></li><li class="chapter-item expanded "><a href="Arithmetic-Evaluation.html"><strong aria-hidden="true">11.</strong> Arithmetic Evaluation</a></li><li class="chapter-item expanded "><a href="Conditional-Expressions.html"><strong aria-hidden="true">12.</strong> Conditional Expressions</a></li><li class="chapter-item expanded "><a href="Prompt-Expansion.html"><strong aria-hidden="true">13.</strong> Prompt Expansion</a></li><li class="chapter-item expanded "><a href="Expansion.html"><strong aria-hidden="true">14.</strong> Expansion</a></li><li class="chapter-item expanded "><a href="Parameters.html"><strong aria-hidden="true">15.</strong> Parameters</a></li><li class="chapter-item expanded "><a href="Options.html"><strong aria-hidden="true">16.</strong> Options</a></li><li class="chapter-item expanded "><a href="Shell-Builtin-Commands.html"><strong aria-hidden="true">17.</strong> Shell Builtin Commands</a></li><li class="chapter-item expanded "><a href="Zsh-Line-Editor.html"><strong aria-hidden="true">18.</strong> Zsh Line Editor</a></li><li class="chapter-item expanded "><a href="Completion-Widgets.html"><strong aria-hidden="true">19.</strong> Completion Widgets</a></li><li class="chapter-item expanded "><a href="Completion-System.html"><strong aria-hidden="true">20.</strong> Completion System</a></li><li class="chapter-item expanded "><a href="Completion-Using-compctl.html"><strong aria-hidden="true">21.</strong> Completion Using compctl</a></li><li class="chapter-item expanded "><a href="Zsh-Modules.html"><strong aria-hidden="true">22.</strong> Zsh Modules</a></li><li class="chapter-item expanded "><a href="Calendar-Function-System.html"><strong aria-hidden="true">23.</strong> Calendar Function System</a></li><li class="chapter-item expanded "><a href="TCP-Function-System.html"><strong aria-hidden="true">24.</strong> TCP Function System</a></li><li class="chapter-item expanded "><a href="Zftp-Function-System.html"><strong aria-hidden="true">25.</strong> Zftp Function System</a></li><li class="chapter-item expanded "><a href="User-Contributions.html"><strong aria-hidden="true">26.</strong> User Contributions</a></li></ol>
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<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="The-Z-Shell-Manual.html#1-the-z-shell-manual">1 The Z Shell Manual</a>
<ul>
<li><a href="The-Z-Shell-Manual.html#11-producing-documentation-from-zshtexi">1.1 Producing documentation from zsh.texi</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="The-Z-Shell-Manual"></span>
<span id="The-Z-Shell-Manual-1"></span></p>
<h1 id="1-the-z-shell-manual"><a class="header" href="#1-the-z-shell-manual">1 The Z Shell Manual</a></h1>
<p>This document has been produced from the texinfo file <code>zsh.texi</code>,
included in the <code>Doc</code> sub-directory of the Zsh distribution.</p>
<hr />
<p><span id="Producing-documentation-from-zsh_002etexi"></span></p>
<h2 id="11-producing-documentation-from-zshtexi"><a class="header" href="#11-producing-documentation-from-zshtexi">1.1 Producing documentation from zsh.texi</a></h2>
<p>The texinfo source may be converted into several formats:</p>
<ul>
<li>
<p>The Info manual<br />
The Info format allows searching for topics, commands, functions,
etc. from the many Indices. The command ‘<code>makeinfo zsh.texi</code>’ is
used to produce the Info documentation.</p>
</li>
<li>
<p>The printed manual<br />
The command ‘<code>texi2dvi zsh.texi</code>’ will output <code>zsh.dvi</code> which can
then be processed with dvips and optionally gs (Ghostscript) to
produce a nicely formatted printed manual.</p>
</li>
<li>
<p>The HTML manual<br />
An HTML version of this manual is available at the Zsh web site via:</p>
<p><code>http://zsh.sourceforge.net/Doc/</code>.</p>
<p>(The HTML version is produced with texi2html, which may be obtained
from <code>http://www.nongnu.org/texi2html/</code>. The command is ‘<code>texi2html –output . –ifinfo –split=chapter –node-files zsh.texi</code>’. If
necessary, upgrade to version 1.78 of texi2html.)</p>
</li>
</ul>
<p>For those who do not have the necessary tools to process texinfo,
precompiled documentation (PostScript, dvi, PDF, info and HTML formats)
is available from the zsh archive site or its mirrors, in the file
<code>zsh-doc.tar.gz</code>. (See <a href="Introduction.html#Availability">Availability</a>
for a list of sites.)</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Introduction.html#2-introduction">2 Introduction</a>
<ul>
<li><a href="Introduction.html#21-author">2.1 Author</a></li>
<li><a href="Introduction.html#22-availability">2.2 Availability</a></li>
<li><a href="Introduction.html#23-mailing-lists">2.3 Mailing Lists</a></li>
<li><a href="Introduction.html#24-the-zsh-faq">2.4 The Zsh FAQ</a></li>
<li><a href="Introduction.html#25-the-zsh-web-page">2.5 The Zsh Web Page</a></li>
<li><a href="Introduction.html#26-the-zsh-userguide">2.6 The Zsh Userguide</a></li>
<li><a href="Introduction.html#27-see-also">2.7 See Also</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Introduction"></span> <span id="Introduction-1"></span></p>
<h1 id="2-introduction"><a class="header" href="#2-introduction">2 Introduction</a></h1>
<p><span id="index-introduction"></span></p>
<p>Zsh is a UNIX command interpreter (shell) usable as an interactive login
shell and as a shell script command processor. Of the standard shells,
zsh most closely resembles ksh but includes many enhancements. It does
not provide compatibility with POSIX or other shells in its default
operating mode: see the section
<a href="Invocation.html#Compatibility">Compatibility</a>.</p>
<p>Zsh has command line editing, builtin spelling correction, programmable
command completion, shell functions (with autoloading), a history
mechanism, and a host of other features.</p>
<hr />
<p><span id="Author"></span> <span id="Author-1"></span></p>
<h2 id="21-author"><a class="header" href="#21-author">2.1 Author</a></h2>
<p><span id="index-author"></span></p>
<p>Zsh was originally written by Paul Falstad <code>&lt;pf@zsh.org&gt;</code>. Zsh is now
maintained by the members of the zsh-workers mailing list
<code>&lt;zsh-workers@zsh.org&gt;</code>. The development is currently coordinated by
Peter Stephenson <code>&lt;pws@zsh.org&gt;</code>. The coordinator can be contacted at
<code>&lt;coordinator@zsh.org&gt;</code>, but matters relating to the code should
generally go to the mailing list.</p>
<hr />
<p><span id="Availability"></span> <span id="Availability-1"></span></p>
<h2 id="22-availability"><a class="header" href="#22-availability">2.2 Availability</a></h2>
<p>Zsh is available from the following HTTP and anonymous FTP site.</p>
<p><span id="index-FTP-sites-for-zsh"></span>
<span id="index-acquiring-zsh-by-FTP"></span>
<span id="index-availability-of-zsh"></span></p>
<p><code>ftp://ftp.zsh.org/pub/</code><br />
<code>https://www.zsh.org/pub/</code> )</p>
<p>The up-to-date source code is available via Git from Sourceforge. See
<code>https://sourceforge.net/projects/zsh/</code> for details. A summary of
instructions for the archive can be found at
<code>http://zsh.sourceforge.net/</code>.</p>
<hr />
<p><span id="Mailing-Lists"></span> <span id="Mailing-Lists-1"></span></p>
<h2 id="23-mailing-lists"><a class="header" href="#23-mailing-lists">2.3 Mailing Lists</a></h2>
<p><span id="index-mailing-lists"></span></p>
<p>Zsh has 3 mailing lists:</p>
<ul>
<li>
<p><code>&lt;zsh-announce@zsh.org&gt;</code><br />
Announcements about releases, major changes in the shell and the
monthly posting of the Zsh FAQ. (moderated)</p>
</li>
<li>
<p><code>&lt;zsh-users@zsh.org&gt;</code><br />
User discussions.</p>
</li>
<li>
<p><code>&lt;zsh-workers@zsh.org&gt;</code><br />
Hacking, development, bug reports and patches.</p>
</li>
</ul>
<p>To subscribe or unsubscribe, send mail to the associated administrative
address for the mailing list.</p>
<p><code>&lt;zsh-announce-subscribe@zsh.org&gt;</code></p>
<p><code>&lt;zsh-users-subscribe@zsh.org&gt;</code></p>
<p><code>&lt;zsh-workers-subscribe@zsh.org&gt;</code></p>
<p><code>&lt;zsh-announce-unsubscribe@zsh.org&gt;</code></p>
<p><code>&lt;zsh-users-unsubscribe@zsh.org&gt;</code></p>
<p><code>&lt;zsh-workers-unsubscribe@zsh.org&gt;</code></p>
<p>YOU ONLY NEED TO JOIN ONE OF THE MAILING LISTS AS THEY ARE NESTED. All
submissions to zsh-announce are automatically forwarded to zsh-users.
All submissions to zsh-users are automatically forwarded to zsh-workers.</p>
<p>If you have problems subscribing/unsubscribing to any of the mailing
lists, send mail to <code>&lt;listmaster@zsh.org&gt;</code>. The mailing lists are
maintained by Karsten Thygesen <code>&lt;karthy@kom.auc.dk&gt;</code>.</p>
<p>The mailing lists are archived; the archives can be accessed via the
administrative addresses listed above. There is also a hypertext
archive, maintained by Geoff Wing <code>&lt;gcw@zsh.org&gt;</code>, available at
<code>https://www.zsh.org/mla/</code>.</p>
<hr />
<p><span id="The-Zsh-FAQ"></span> <span id="The-Zsh-FAQ-1"></span></p>
<h2 id="24-the-zsh-faq"><a class="header" href="#24-the-zsh-faq">2.4 The Zsh FAQ</a></h2>
<p>Zsh has a list of Frequently Asked Questions (FAQ), maintained by Peter
Stephenson <code>&lt;pws@zsh.org&gt;</code>. It is regularly posted to the newsgroup
comp.unix.shell and the zsh-announce mailing list. The latest version
can be found at any of the Zsh FTP sites, or at
<code>http://www.zsh.org/FAQ/</code>. The contact address for FAQ-related matters
is <code>&lt;faqmaster@zsh.org&gt;</code>.</p>
<hr />
<p><span id="The-Zsh-Web-Page"></span>
<span id="The-Zsh-Web-Page-1"></span></p>
<h2 id="25-the-zsh-web-page"><a class="header" href="#25-the-zsh-web-page">2.5 The Zsh Web Page</a></h2>
<p>Zsh has a web page which is located at <code>https://www.zsh.org/</code>. This is
maintained by Karsten Thygesen <code>&lt;karthy@zsh.org&gt;</code>, of SunSITE Denmark.
The contact address for web-related matters is <code>&lt;webmaster@zsh.org&gt;</code>.</p>
<hr />
<p><span id="The-Zsh-Userguide"></span>
<span id="The-Zsh-Userguide-1"></span></p>
<h2 id="26-the-zsh-userguide"><a class="header" href="#26-the-zsh-userguide">2.6 The Zsh Userguide</a></h2>
<p>A userguide is currently in preparation. It is intended to complement
the manual, with explanations and hints on issues where the manual can
be cabbalistic, hierographic, or downright mystifying (for example, the
word ‘hierographic’ does not exist). It can be viewed in its current
state at <code>http://zsh.sourceforge.net/Guide/</code>. At the time of writing,
chapters dealing with startup files and their contents and the new
completion system were essentially complete.</p>
<hr />
<p><span id="See-Also"></span> <span id="See-Also-1"></span></p>
<h2 id="27-see-also"><a class="header" href="#27-see-also">2.7 See Also</a></h2>
<p>man page sh(1), man page csh(1), man page tcsh(1), man page rc(1), man
page bash(1), man page ksh(1)</p>
<p>IEEE Standard for information Technology - Part 2: Shell and Utilities,
IEEE Inc, 1993, ISBN 1-55937-255-9.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Roadmap.html#3-roadmap">3 Roadmap</a>
<ul>
<li><a href="Roadmap.html#31-when-the-shell-starts">3.1 When the shell starts</a></li>
<li><a href="Roadmap.html#32-interactive-use">3.2 Interactive Use</a>
<ul>
<li><a href="Roadmap.html#321-completion">3.2.1 Completion</a></li>
<li><a href="Roadmap.html#322-extending-the-line-editor">3.2.2 Extending the line editor</a></li>
</ul>
</li>
<li><a href="Roadmap.html#33-options">3.3 Options</a></li>
<li><a href="Roadmap.html#34-pattern-matching">3.4 Pattern Matching</a></li>
<li><a href="Roadmap.html#35-general-comments-on-syntax">3.5 General Comments on Syntax</a></li>
<li><a href="Roadmap.html#36-programming">3.6 Programming</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Roadmap"></span> <span id="Roadmap-1"></span></p>
<h1 id="3-roadmap"><a class="header" href="#3-roadmap">3 Roadmap</a></h1>
<p><span id="index-roadmap"></span></p>
<p>The Zsh Manual, like the shell itself, is large and often complicated.
This section of the manual provides some pointers to areas of the shell
that are likely to be of particular interest to new users, and indicates
where in the rest of the manual the documentation is to be found.</p>
<hr />
<p><span id="When-the-shell-starts"></span></p>
<h2 id="31-when-the-shell-starts"><a class="header" href="#31-when-the-shell-starts">3.1 When the shell starts</a></h2>
<p>When it starts, the shell reads commands from various files. These can
be created or edited to customize the shell. See
<a href="Files.html#Files">Files</a>.</p>
<p>If no personal initialization files exist for the current user, a
function is run to help you change some of the most common settings. It
won’t appear if your administrator has disabled the <code>zsh/newuser</code>
module. The function is designed to be self-explanatory. You can run it
by hand with ‘<code>autoload -Uz zsh-newuser-install; zsh-newuser-install -f</code>’. See also <a href="User-Contributions.html#User-Configuration-Functions">User Configuration
Functions</a>.</p>
<hr />
<p><span id="Interactive-Use"></span></p>
<h2 id="32-interactive-use"><a class="header" href="#32-interactive-use">3.2 Interactive Use</a></h2>
<p>Interaction with the shell uses the builtin Zsh Line Editor, ZLE. This
is described in detail in <a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh Line
Editor</a>.</p>
<p>The first decision a user must make is whether to use the Emacs or Vi
editing mode as the keys for editing are substantially different. Emacs
editing mode is probably more natural for beginners and can be selected
explicitly with the command <code>bindkey -e</code>.</p>
<p>A history mechanism for retrieving previously typed lines (most simply
with the Up or Down arrow keys) is available; note that, unlike other
shells, zsh will not save these lines when the shell exits unless you
set appropriate variables, and the number of history lines retained by
default is quite small (30 lines). See the description of the shell
variables (referred to in the documentation as parameters) <code>HISTFILE</code>,
<code>HISTSIZE</code> and <code>SAVEHIST</code> in <a href="Parameters.html#Parameters-Used-By-The-Shell">Parameters Used By The
Shell</a>. Note that it’s
currently only possible to read and write files saving history when the
shell is interactive, i.e. it does not work from scripts.</p>
<p>The shell now supports the UTF-8 character set (and also others if
supported by the operating system). This is (mostly) handled
transparently by the shell, but the degree of support in terminal
emulators is variable. There is some discussion of this in the shell
FAQ, <code>http://www.zsh.org/FAQ/</code>. Note in particular that for combining
characters to be handled the option <code>COMBINING_CHARS</code> needs to be set.
Because the shell is now more sensitive to the definition of the
character set, note that if you are upgrading from an older version of
the shell you should ensure that the appropriate variable, either <code>LANG</code>
(to affect all aspects of the shell’s operation) or <code>LC_CTYPE</code> (to
affect only the handling of character sets) is set to an appropriate
value. This is true even if you are using a single-byte character set
including extensions of ASCII such as <code>ISO-8859-1</code> or <code>ISO-8859-15</code>. See
the description of <code>LC_CTYPE</code> in
<a href="Parameters.html#Parameters">Parameters</a>.</p>
<hr />
<p><span id="Completion-1"></span></p>
<h3 id="321-completion"><a class="header" href="#321-completion">3.2.1 Completion</a></h3>
<p>Completion is a feature present in many shells. It allows the user to
type only a part (usually the prefix) of a word and have the shell fill
in the rest. The completion system in zsh is programmable. For example,
the shell can be set to complete email addresses in arguments to the
mail command from your <code>~/.abook/addressbook</code>; usernames, hostnames, and
even remote paths in arguments to scp, and so on. Anything that can be
written in or glued together with zsh can be the source of what the line
editor offers as possible completions.</p>
<p>Zsh has two completion systems, an old, so called <code>compctl</code> completion
(named after the builtin command that serves as its complete and only
user interface), and a new one, referred to as <code>compsys</code>, organized as
library of builtin and user-defined functions. The two systems differ in
their interface for specifying the completion behavior. The new system
is more customizable and is supplied with completions for many commonly
used commands; it is therefore to be preferred.</p>
<p>The completion system must be enabled explicitly when the shell starts.
For more information see <a href="Completion-System.html#Completion-System">Completion
System</a>.</p>
<hr />
<p><span id="Extending-the-line-editor"></span></p>
<h3 id="322-extending-the-line-editor"><a class="header" href="#322-extending-the-line-editor">3.2.2 Extending the line editor</a></h3>
<p>Apart from completion, the line editor is highly extensible by means of
shell functions. Some useful functions are provided with the shell; they
provide facilities such as:</p>
<ul>
<li>
<p><code>insert-composed-char</code><br />
composing characters not found on the keyboard</p>
</li>
<li>
<p><code>match-words-by-style</code><br />
configuring what the line editor considers a word when moving or
deleting by word</p>
</li>
<li>
<p><code>history-beginning-search-backward-end</code>, etc.<br />
alternative ways of searching the shell history</p>
</li>
<li>
<p><code>replace-string</code>, <code>replace-pattern</code><br />
functions for replacing strings or patterns globally in the command
line</p>
</li>
<li>
<p><code>edit-command-line</code><br />
edit the command line with an external editor.</p>
</li>
</ul>
<p>See <a href="User-Contributions.html#ZLE-Functions">ZLE Functions</a> for
descriptions of these.</p>
<hr />
<p><span id="Options-3"></span></p>
<h2 id="33-options"><a class="header" href="#33-options">3.3 Options</a></h2>
<p>The shell has a large number of options for changing its behaviour.
These cover all aspects of the shell; browsing the full documentation is
the only good way to become acquainted with the many possibilities. See
<a href="Options.html#Options">Options</a>.</p>
<hr />
<p><span id="Pattern-Matching"></span></p>
<h2 id="34-pattern-matching"><a class="header" href="#34-pattern-matching">3.4 Pattern Matching</a></h2>
<p>The shell has a rich set of patterns which are available for file
matching (described in the documentation as ‘filename generation’ and
also known for historical reasons as ‘globbing’) and for use when
programming. These are described in <a href="Expansion.html#Filename-Generation">Filename
Generation</a>.</p>
<p>Of particular interest are the following patterns that are not commonly
supported by other systems of pattern matching:</p>
<ul>
<li>
<p><code>**</code><br />
for matching over multiple directories</p>
</li>
<li>
<p><code>|</code><br />
for matching either of two alternatives</p>
</li>
<li>
<p><code>~</code>, <code>^</code><br />
the ability to exclude patterns from matching when the
<code>EXTENDED_GLOB</code> option is set</p>
</li>
<li>
<p><code>(``...``)</code><br />
glob qualifiers, included in parentheses at the end of the pattern,
which select files by type (such as directories) or attribute (such
as size).</p>
</li>
</ul>
<hr />
<p><span id="General-Comments-on-Syntax"></span></p>
<h2 id="35-general-comments-on-syntax"><a class="header" href="#35-general-comments-on-syntax">3.5 General Comments on Syntax</a></h2>
<p>Although the syntax of zsh is in ways similar to the Korn shell, and
therefore more remotely to the original UNIX shell, the Bourne shell,
its default behaviour does not entirely correspond to those shells.
General shell syntax is introduced in <a href="Shell-Grammar.html#Shell-Grammar">Shell
Grammar</a>.</p>
<p>One commonly encountered difference is that variables substituted onto
the command line are not split into words. See the description of the
shell option <code>SH_WORD_SPLIT</code> in <a href="Expansion.html#Parameter-Expansion">Parameter
Expansion</a>. In zsh, you can either
explicitly request the splitting (e.g. <code>${=foo}</code>) or use an array when
you want a variable to expand to more than one word. See <a href="Parameters.html#Array-Parameters">Array
Parameters</a>.</p>
<hr />
<p><span id="Programming"></span></p>
<h2 id="36-programming"><a class="header" href="#36-programming">3.6 Programming</a></h2>
<p>The most convenient way of adding enhancements to the shell is typically
by writing a shell function and arranging for it to be autoloaded.
Functions are described in <a href="Functions.html#Functions">Functions</a>. Users
changing from the C shell and its relatives should notice that aliases
are less used in zsh as they don’t perform argument substitution, only
simple text replacement.</p>
<p>A few general functions, other than those for the line editor described
above, are provided with the shell and are described in <a href="User-Contributions.html#User-Contributions">User
Contributions</a>. Features
include:</p>
<ul>
<li>
<p><code>promptinit</code><br />
a prompt theme system for changing prompts easily, see <a href="User-Contributions.html#Prompt-Themes">Prompt
Themes</a></p>
</li>
<li>
<p><code>zsh-mime-setup</code><br />
a MIME-handling system which dispatches commands according to the
suffix of a file as done by graphical file managers</p>
</li>
<li>
<p><code>zcalc</code><br />
a calculator</p>
</li>
<li>
<p><code>zargs</code><br />
a version of <code>xargs</code> that makes the <code>find</code> command redundant</p>
</li>
<li>
<p><code>zmv</code><br />
a command for renaming files by means of shell patterns.</p>
</li>
</ul>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Invocation.html#4-invocation">4 Invocation</a>
<ul>
<li><a href="Invocation.html#41-invocation">4.1 Invocation</a></li>
<li><a href="Invocation.html#42-compatibility">4.2 Compatibility</a></li>
<li><a href="Invocation.html#43-restricted-shell">4.3 Restricted Shell</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Invocation"></span> <span id="Invocation-1"></span></p>
<h1 id="4-invocation"><a class="header" href="#4-invocation">4 Invocation</a></h1>
<p><span id="index-invocation"></span></p>
<hr />
<p><span id="Invocation-2"></span></p>
<h2 id="41-invocation"><a class="header" href="#41-invocation">4.1 Invocation</a></h2>
<p><span id="index-shell-options"></span>
<span id="index-options_002c-shell"></span>
<span id="index-shell-flags"></span>
<span id="index-flags_002c-shell"></span></p>
<p>The following flags are interpreted by the shell when invoked to
determine where the shell will read commands from:</p>
<ul>
<li>
<p><code>-c</code><br />
Take the first argument as a command to execute, rather than reading
commands from a script or standard input. If any further arguments
are given, the first one is assigned to <code>$0</code>, rather than being used
as a positional parameter.</p>
</li>
<li>
<p><code>-i</code><br />
Force shell to be interactive. It is still possible to specify a
script to execute.</p>
</li>
<li>
<p><code>-s</code><br />
Force shell to read commands from the standard input. If the <code>-s</code>
flag is not present and an argument is given, the first argument is
taken to be the pathname of a script to execute.</p>
</li>
</ul>
<p>If there are any remaining arguments after option processing, and
neither of the options <code>-c</code> or <code>-s</code> was supplied, the first argument is
taken as the file name of a script containing shell commands to be
executed. If the option <code>PATH_SCRIPT</code> is set, and the file name does not
contain a directory path (i.e. there is no ‘<code>/</code>’ in the name), first the
current directory and then the command path given by the variable <code>PATH</code>
are searched for the script. If the option is not set or the file name
contains a ‘<code>/</code>’ it is used directly.</p>
<p>After the first one or two arguments have been appropriated as described
above, the remaining arguments are assigned to the positional
parameters.</p>
<p>For further options, which are common to invocation and the <code>set</code>
builtin, see <a href="Options.html#Options">Options</a>.</p>
<p>The long option ‘<code>-``-emulate</code>’ followed (in a separate word) by an
emulation mode may be passed to the shell. The emulation modes are those
described for the <code>emulate</code> builtin, see <a href="Shell-Builtin-Commands.html#Shell-Builtin-Commands">Shell Builtin
Commands</a>. The
‘<code>-``-emulate</code>’ option must precede any other options (which might
otherwise be overridden), but following options are honoured, so may be
used to modify the requested emulation mode. Note that certain extra
steps are taken to ensure a smooth emulation when this option is used
compared with the <code>emulate</code> command within the shell: for example,
variables that conflict with POSIX usage such as <code>path</code> are not defined
within the shell.</p>
<p>Options may be specified by name using the <code>-o</code> option. <code>-o</code> acts like a
single-letter option, but takes a following string as the option name.
For example,</p>
<div class="example">
<pre><code class="language-example">zsh -x -o shwordsplit scr
</code></pre>
</div>
<p>runs the script <code>scr</code>, setting the <code>XTRACE</code> option by the corresponding
letter ‘<code>-x</code>’ and the <code>SH_WORD_SPLIT</code> option by name. Options may be
turned <em>off</em> by name by using <code>+o</code> instead of <code>-o</code>. <code>-o</code> can be stacked
up with preceding single-letter options, so for example ‘<code>-xo shwordsplit</code>’ or ‘<code>-xoshwordsplit</code>’ is equivalent to ‘<code>-x -o shwordsplit</code>’.</p>
<p><span id="index-long-option"></span></p>
<p>Options may also be specified by name in GNU long option style,
‘<code>-``-``option-name</code>’. When this is done, ‘<code>-</code>’ characters in the
option name are permitted: they are translated into ‘<code>_</code>’, and thus
ignored. So, for example, ‘<code>zsh -``-sh-word-split</code>’ invokes zsh with the
<code>SH_WORD_SPLIT</code> option turned on. Like other option syntaxes, options
can be turned off by replacing the initial ‘<code>-</code>’ with a ‘<code>+</code>’; thus
‘<code>+-sh-word-split</code>’ is equivalent to ‘<code>-``-no-sh-word-split</code>’. Unlike
other option syntaxes, GNU-style long options cannot be stacked with any
other options, so for example ‘<code>-x-shwordsplit</code>’ is an error, rather
than being treated like ‘<code>-x -``-shwordsplit</code>’.</p>
<p><span id="index-_002d_002dversion"></span>
<span id="index-_002d_002dhelp"></span></p>
<p>The special GNU-style option ‘<code>-``-version</code>’ is handled; it sends to
standard output the shell’s version information, then exits
successfully. ‘<code>-``-help</code>’ is also handled; it sends to standard output
a list of options that can be used when invoking the shell, then exits
successfully.</p>
<p>Option processing may be finished, allowing following arguments that
start with ‘<code>-</code>’ or ‘<code>+</code>’ to be treated as normal arguments, in two
ways. Firstly, a lone ‘<code>-</code>’ (or ‘<code>+</code>’) as an argument by itself ends
option processing. Secondly, a special option ‘<code>-``-</code>’ (or ‘<code>+-</code>’),
which may be specified on its own (which is the standard POSIX usage) or
may be stacked with preceding options (so ‘<code>-x-</code>’ is equivalent to ‘<code>-x -``-</code>’). Options are not permitted to be stacked after ‘<code>-``-</code>’ (so
‘<code>-x-f</code>’ is an error), but note the GNU-style option form discussed
above, where ‘<code>-``-shwordsplit</code>’ is permitted and does not end option
processing.</p>
<p>Except when the sh/ksh emulation single-letter options are in effect,
the option ‘<code>-b</code>’ (or ‘<code>+b</code>’) ends option processing. ‘<code>-b</code>’ is like
‘<code>-``-</code>’, except that further single-letter options can be stacked
after the ‘<code>-b</code>’ and will take effect as normal.</p>
<hr />
<p><span id="Compatibility"></span> <span id="Compatibility-1"></span></p>
<h2 id="42-compatibility"><a class="header" href="#42-compatibility">4.2 Compatibility</a></h2>
<p><span id="index-compatibility"></span>
<span id="index-sh-compatibility"></span>
<span id="index-ksh-compatibility"></span></p>
<p>Zsh tries to emulate sh or ksh when it is invoked as <code>sh</code> or <code>ksh</code>
respectively; more precisely, it looks at the first letter of the name
by which it was invoked, excluding any initial ‘<code>r</code>’ (assumed to stand
for ‘restricted’), and if that is ‘<code>b</code>’, ‘<code>s</code>’ or ‘<code>k</code>’ it will emulate
sh or ksh. Furthermore, if invoked as <code>su</code> (which happens on certain
systems when the shell is executed by the <code>su</code> command), the shell will
try to find an alternative name from the <code>SHELL</code> environment variable
and perform emulation based on that.</p>
<p>In sh and ksh compatibility modes the following parameters are not
special and not initialized by the shell: <code>ARGC</code>, <code>argv</code>, <code>cdpath</code>,
<code>fignore</code>, <code>fpath</code>, <code>HISTCHARS</code>, <code>mailpath</code>, <code>MANPATH</code>, <code>manpath</code>,
<code>path</code>, <code>prompt</code>, <code>PROMPT</code>, <code>PROMPT2</code>, <code>PROMPT3</code>, <code>PROMPT4</code>, <code>psvar</code>,
<code>status</code>, <code>watch</code>.</p>
<p><span id="index-ENV_002c-use-of"></span></p>
<p>The usual zsh startup/shutdown scripts are not executed. Login shells
source <code>/etc/profile</code> followed by <code>$HOME/.profile</code>. If the <code>ENV</code>
environment variable is set on invocation, <code>$ENV</code> is sourced after the
profile scripts. The value of <code>ENV</code> is subjected to parameter expansion,
command substitution, and arithmetic expansion before being interpreted
as a pathname. Note that the <code>PRIVILEGED</code> option also affects the
execution of startup files.</p>
<p>The following options are set if the shell is invoked as <code>sh</code> or <code>ksh</code>:
<code>NO_BAD_PATTERN</code>, <code>NO_BANG_HIST</code>, <code>NO_BG_NICE</code>, <code>NO_EQUALS</code>,
<code>NO_FUNCTION_ARGZERO</code>, <code>GLOB_SUBST</code>, <code>NO_GLOBAL_EXPORT</code>, <code>NO_HUP</code>,
<code>INTERACTIVE_COMMENTS</code>, <code>KSH_ARRAYS</code>, <code>NO_MULTIOS</code>, <code>NO_NOMATCH</code>,
<code>NO_NOTIFY</code>, <code>POSIX_BUILTINS</code>, <code>NO_PROMPT_PERCENT</code>, <code>RM_STAR_SILENT</code>,
<code>SH_FILE_EXPANSION</code>, <code>SH_GLOB</code>, <code>SH_OPTION_LETTERS</code>, <code>SH_WORD_SPLIT</code>.
Additionally the <code>BSD_ECHO</code> and <code>IGNORE_BRACES</code> options are set if zsh
is invoked as <code>sh</code>. Also, the <code>KSH_OPTION_PRINT</code>, <code>LOCAL_OPTIONS</code>,
<code>PROMPT_BANG</code>, <code>PROMPT_SUBST</code> and <code>SINGLE_LINE_ZLE</code> options are set if
zsh is invoked as <code>ksh</code>.</p>
<hr />
<p><span id="Restricted-Shell"></span>
<span id="Restricted-Shell-1"></span></p>
<h2 id="43-restricted-shell"><a class="header" href="#43-restricted-shell">4.3 Restricted Shell</a></h2>
<p><span id="index-restricted-shell"></span>
<span id="index-RESTRICTED"></span></p>
<p>When the basename of the command used to invoke zsh starts with the
letter ‘<code>r</code>’ or the ‘<code>-r</code>’ command line option is supplied at
invocation, the shell becomes restricted. Emulation mode is determined
after stripping the letter ‘<code>r</code>’ from the invocation name. The following
are disabled in restricted mode:</p>
<ul>
<li>changing directories with the <code>cd</code> builtin</li>
<li>changing or unsetting the <code>EGID</code>, <code>EUID</code>, <code>GID</code>, <code>HISTFILE</code>,
<code>HISTSIZE</code>, <code>IFS</code>, <code>LD_AOUT_LIBRARY_PATH</code>, <code>LD_AOUT_PRELOAD</code>,
<code>LD_LIBRARY_PATH</code>, <code>LD_PRELOAD</code>, <code>MODULE_PATH</code>, <code>module_path</code>,
<code>PATH</code>, <code>path</code>, <code>SHELL</code>, <code>UID</code> and <code>USERNAME</code> parameters</li>
<li>specifying command names containing <code>/</code></li>
<li>specifying command pathnames using <code>hash</code></li>
<li>redirecting output to files</li>
<li>using the <code>exec</code> builtin command to replace the shell with another
command</li>
<li>using <code>jobs -Z</code> to overwrite the shell process’ argument and
environment space</li>
<li>using the <code>ARGV0</code> parameter to override <code>argv[0]</code> for external
commands</li>
<li>turning off restricted mode with <code>set +r</code> or <code>unsetopt RESTRICTED</code></li>
</ul>
<p>These restrictions are enforced after processing the startup files. The
startup files should set up <code>PATH</code> to point to a directory of commands
which can be safely invoked in the restricted environment. They may also
add further restrictions by disabling selected builtins.</p>
<p>Restricted mode can also be activated any time by setting the
<code>RESTRICTED</code> option. This immediately enables all the restrictions
described above even if the shell still has not processed all startup
files.</p>
<p>A shell <em>Restricted Mode</em> is an outdated way to restrict what users may
do: modern systems have better, safer and more reliable ways to confine
user actions, such as <em>chroot jails</em>, <em>containers</em> and <em>zones</em>.</p>
<p>A restricted shell is very difficult to implement safely. The feature
may be removed in a future version of zsh.</p>
<p>It is important to realise that the restrictions only apply to the
shell, not to the commands it runs (except for some shell builtins).
While a restricted shell can only run the restricted list of commands
accessible via the predefined ‘<code>PATH</code>’ variable, it does not prevent
those commands from running any other command.</p>
<p>As an example, if ‘<code>env</code>’ is among the list of <em>allowed</em> commands, then
it allows the user to run any command as ‘<code>env</code>’ is not a shell</p>
<p>So when implementing a restricted shell framework it is important to be
fully aware of what actions each of the <em>allowed</em> commands or features
(which may be regarded as <em>modules</em>) can perform.</p>
<p>Many commands can have their behaviour affected by environment
variables. Except for the few listed above, zsh does not restrict the
setting of environment variables.</p>
<p>If a ‘<code>perl</code>’, ‘<code>python</code>’, ‘<code>bash</code>’, or other general purpose
interpreted script it treated as a restricted command, the user can work
around the restriction by setting specially crafted ‘<code>PERL5LIB</code>’,
‘<code>PYTHONPATH</code>’, ‘<code>BASHENV</code>’ (etc.) environment variables. On GNU
systems, any command can be made to run arbitrary code when performing
character set conversion (including zsh itself) by setting a
‘<code>GCONV_PATH</code>’ environment variable. Those are only a few examples.</p>
<p>Bear in mind that, contrary to some other shells, ‘<code>readonly</code>’ is not a
security feature in zsh as it can be undone and so cannot be used to
mitigate the above.</p>
<p>A restricted shell only works if the allowed commands are few and
carefully written so as not to grant more access to users than intended.
It is also important to restrict what zsh module the user may load as
some of them, such as ‘<code>zsh/system</code>’, ‘<code>zsh/mapfile</code>’ and ‘<code>zsh/files</code>’,
allow bypassing most of the restrictions.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Files.html#5-files">5 Files</a>
<ul>
<li><a href="Files.html#51-startupshutdown-files">5.1 Startup/Shutdown Files</a></li>
<li><a href="Files.html#52-files">5.2 Files</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Files"></span> <span id="Files-1"></span></p>
<h1 id="5-files"><a class="header" href="#5-files">5 Files</a></h1>
<hr />
<p><span id="Startup_002fShutdown-Files"></span></p>
<h2 id="51-startupshutdown-files"><a class="header" href="#51-startupshutdown-files">5.1 Startup/Shutdown Files</a></h2>
<p><span id="index-files_002c-startup"></span>
<span id="index-startup-files"></span>
<span id="index-files_002c-shutdown"></span>
<span id="index-shutdown-files"></span>
<span id="index-RCS_002c-use-of"></span>
<span id="index-GLOBAL_005fRCS_002c-use-of"></span>
<span id="index-NO_005fRCS_002c-use-of"></span>
<span id="index-NO_005fGLOBAL_005fRCS_002c-use-of"></span>
<span id="index-ZDOTDIR_002c-use-of"></span>
<span id="index-zshenv"></span></p>
<p>Commands are first read from <code>/etc/zshenv</code>; this cannot be overridden.
Subsequent behaviour is modified by the <code>RCS</code> and <code>GLOBAL_RCS</code> options;
the former affects all startup files, while the second only affects
global startup files (those shown here with an path starting with a
<code>/</code>). If one of the options is unset at any point, any subsequent
startup file(s) of the corresponding type will not be read. It is also
possible for a file in <code>$ZDOTDIR</code> to re-enable <code>GLOBAL_RCS</code>. Both <code>RCS</code>
and <code>GLOBAL_RCS</code> are set by default.</p>
<p>Commands are then read from <code>$ZDOTDIR/.zshenv</code>.
<span id="index-LOGIN_002c-use-of"></span>
<span id="index-zprofile"></span> If the shell is a login shell,
commands are read from <code>/etc/zprofile</code> and then <code>$ZDOTDIR/.zprofile</code>.
<span id="index-zshrc"></span> Then, if the shell is interactive,
commands are read from <code>/etc/zshrc</code> and then <code>$ZDOTDIR/.zshrc</code>.
<span id="index-zlogin"></span> Finally, if the shell is a login shell,
<code>/etc/zlogin</code> and <code>$ZDOTDIR/.zlogin</code> are read.</p>
<p><span id="index-zlogout"></span></p>
<p>When a login shell exits, the files <code>$ZDOTDIR/.zlogout</code> and then
<code>/etc/zlogout</code> are read. This happens with either an explicit exit via
the <code>exit</code> or <code>logout</code> commands, or an implicit exit by reading
end-of-file from the terminal. However, if the shell terminates due to
<code>exec</code>’ing another process, the logout files are not read. These are
also affected by the <code>RCS</code> and <code>GLOBAL_RCS</code> options. Note also that the
<code>RCS</code> option affects the saving of history files, i.e. if <code>RCS</code> is unset
when the shell exits, no history file will be saved.</p>
<p><span id="index-HOME_002c-use-of"></span></p>
<p>If <code>ZDOTDIR</code> is unset, <code>HOME</code> is used instead. Files listed above as
being in <code>/etc</code> may be in another directory, depending on the
installation.</p>
<p>As <code>/etc/zshenv</code> is run for all instances of zsh, it is important that
it be kept as small as possible. In particular, it is a good idea to put
code that does not need to be run for every single shell behind a test
of the form ‘<code>if [[ -o rcs ]]; then ...</code>’ so that it will not be
executed when zsh is invoked with the ‘<code>-f</code>’ option.</p>
<hr />
<p><span id="Files-2"></span></p>
<h2 id="52-files"><a class="header" href="#52-files">5.2 Files</a></h2>
<p><span id="index-files-used"></span></p>
<p><code>$ZDOTDIR/.zshenv</code></p>
<p><code>$ZDOTDIR/.zprofile</code></p>
<p><code>$ZDOTDIR/.zshrc</code></p>
<p><code>$ZDOTDIR/.zlogin</code></p>
<p><code>$ZDOTDIR/.zlogout</code></p>
<p><code>${TMPPREFIX}*</code> (default is /tmp/zsh*)</p>
<p><code>/etc/zshenv</code></p>
<p><code>/etc/zprofile</code></p>
<p><code>/etc/zshrc</code></p>
<p><code>/etc/zlogin</code></p>
<p><code>/etc/zlogout</code> (installation-specific - <code>/etc</code> is the default)</p>
<p>Any of these files may be pre-compiled with the <code>zcompile</code> builtin
command (<a href="Shell-Builtin-Commands.html#Shell-Builtin-Commands">Shell Builtin
Commands</a>). If a
compiled file exists (named for the original file plus the <code>.zwc</code>
extension) and it is newer than the original file, the compiled file
will be used instead.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Shell-Grammar.html#6-shell-grammar">6 Shell Grammar</a>
<ul>
<li><a href="Shell-Grammar.html#61-simple-commands--pipelines">6.1 Simple Commands &amp; Pipelines</a></li>
<li><a href="Shell-Grammar.html#62-precommand-modifiers">6.2 Precommand Modifiers</a></li>
<li><a href="Shell-Grammar.html#63-complex-commands">6.3 Complex Commands</a></li>
<li><a href="Shell-Grammar.html#64-alternate-forms-for-complex-commands">6.4 Alternate Forms For Complex Commands</a></li>
<li><a href="Shell-Grammar.html#65-reserved-words">6.5 Reserved Words</a></li>
<li><a href="Shell-Grammar.html#66-errors">6.6 Errors</a></li>
<li><a href="Shell-Grammar.html#67-comments">6.7 Comments</a></li>
<li><a href="Shell-Grammar.html#68-aliasing">6.8 Aliasing</a>
<ul>
<li><a href="Shell-Grammar.html#681-alias-difficulties">6.8.1 Alias difficulties</a></li>
</ul>
</li>
<li><a href="Shell-Grammar.html#69-quoting">6.9 Quoting</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Shell-Grammar"></span> <span id="Shell-Grammar-1"></span></p>
<h1 id="6-shell-grammar"><a class="header" href="#6-shell-grammar">6 Shell Grammar</a></h1>
<p><span id="index-shell-grammar"></span>
<span id="index-grammar_002c-shell"></span></p>
<hr />
<p><span id="Simple-Commands-_0026-Pipelines"></span>
<span id="Simple-Commands-_0026-Pipelines-1"></span></p>
<h2 id="61-simple-commands--pipelines"><a class="header" href="#61-simple-commands--pipelines">6.1 Simple Commands &amp; Pipelines</a></h2>
<p><span id="index-simple-commands"></span>
<span id="index-commands_002c-simple"></span></p>
<p>A <em>simple command</em> is a sequence of optional parameter assignments
followed by blank-separated words, with optional redirections
interspersed. For a description of assignment, see the beginning of
<a href="Parameters.html#Parameters">Parameters</a>.</p>
<p>The first word is the command to be executed, and the remaining words,
if any, are arguments to the command. If a command name is given, the
parameter assignments modify the environment of the command when it is
executed. The value of a simple command is its exit status, or 128 plus
the signal number if terminated by a signal. For example,</p>
<div class="example">
<pre><code class="language-example">echo foo
</code></pre>
</div>
<p>is a simple command with arguments.</p>
<p><span id="index-pipeline"></span></p>
<p>A <em>pipeline</em> is either a simple command, or a sequence of two or more
simple commands where each command is separated from the next by ‘<code>|</code>’
or ‘<code>|&amp;</code>’. Where commands are separated by ‘<code>|</code>’, the standard output of
the first command is connected to the standard input of the next. ‘<code>|&amp;</code>’
is shorthand for ‘<code>2&gt;&amp;1 |</code>’, which connects both the standard output and
the standard error of the command to the standard input of the next. The
value of a pipeline is the value of the last command, unless the
pipeline is preceded by ‘<code>!</code>’ in which case the value is the logical
inverse of the value of the last command. For example,</p>
<div class="example">
<pre><code class="language-example">echo foo | sed 's/foo/bar/'
</code></pre>
</div>
<p>is a pipeline, where the output (‘<code>foo</code>’ plus a newline) of the first
command will be passed to the input of the second.</p>
<p><span id="index-coproc"></span> <span id="index-coprocess"></span></p>
<p>If a pipeline is preceded by ‘<code>coproc</code>’, it is executed as a coprocess;
a two-way pipe is established between it and the parent shell. The shell
can read from or write to the coprocess by means of the ‘<code>&gt;&amp;p</code>’ and
‘<code>&lt;&amp;p</code>’ redirection operators or with ‘<code>print -p</code>’ and ‘<code>read -p</code>’. A
pipeline cannot be preceded by both ‘<code>coproc</code>’ and ‘<code>!</code>’. If job control
is active, the coprocess can be treated in other than input and output
as an ordinary background job.</p>
<p><span id="index-sublist"></span></p>
<p>A <em>sublist</em> is either a single pipeline, or a sequence of two or more
pipelines separated by ‘<code>&amp;&amp;</code>’ or ‘<code>||</code>’. If two pipelines are separated
by ‘<code>&amp;&amp;</code>’, the second pipeline is executed only if the first succeeds
(returns a zero status). If two pipelines are separated by ‘<code>||</code>’, the
second is executed only if the first fails (returns a nonzero status).
Both operators have equal precedence and are left associative. The value
of the sublist is the value of the last pipeline executed. For example,</p>
<div class="example">
<pre><code class="language-example">dmesg | grep panic &amp;&amp; print yes
</code></pre>
</div>
<p>is a sublist consisting of two pipelines, the second just a simple
command which will be executed if and only if the <code>grep</code> command returns
a zero status. If it does not, the value of the sublist is that return
status, else it is the status returned by the <code>print</code> (almost certainly
zero).</p>
<p><span id="index-list"></span></p>
<p>A <em>list</em> is a sequence of zero or more sublists, in which each sublist
is terminated by ‘<code>;</code>’, ‘<code>&amp;</code>’, ‘<code>&amp;|</code>’, ‘<code>&amp;!</code>’, or a newline. This
terminator may optionally be omitted from the last sublist in the list
when the list appears as a complex command inside ‘<code>(</code>...<code>)</code>’ or
‘<code>{</code>...<code>}</code>’. When a sublist is terminated by ‘<code>;</code>’ or newline, the
shell waits for it to finish before executing the next sublist. If a
sublist is terminated by a ‘<code>&amp;</code>’, ‘<code>&amp;|</code>’, or ‘<code>&amp;!</code>’, the shell executes
the last pipeline in it in the background, and does not wait for it to
finish (note the difference from other shells which execute the whole
sublist in the background). A backgrounded pipeline returns a status of
zero.</p>
<p>More generally, a list can be seen as a set of any shell commands
whatsoever, including the complex commands below; this is implied
wherever the word ‘list’ appears in later descriptions. For example, the
commands in a shell function form a special sort of list.</p>
<hr />
<p><span id="Precommand-Modifiers"></span>
<span id="Precommand-Modifiers-1"></span></p>
<h2 id="62-precommand-modifiers"><a class="header" href="#62-precommand-modifiers">6.2 Precommand Modifiers</a></h2>
<p><span id="index-precommand-modifiers"></span>
<span id="index-modifiers_002c-precommand"></span></p>
<p>A simple command may be preceded by a <em>precommand modifier</em>, which will
alter how the command is interpreted. These modifiers are shell builtin
commands with the exception of <code>nocorrect</code> which is a reserved word.</p>
<p><span id="index-_002d"></span></p>
<p><code>-</code></p>
<p>The command is executed with a ‘<code>-</code>’ prepended to its <code>argv[0]</code> string.</p>
<p><span id="index-builtin"></span></p>
<p><code>builtin</code></p>
<p>The command word is taken to be the name of a builtin command, rather
than a shell function or external command.</p>
<p><span id="index-command"></span></p>
<p><code>command</code> [ <code>-pvV</code> ]</p>
<p>The command word is taken to be the name of an external command, rather
than a shell function or builtin. If the <code>POSIX_BUILTINS</code> option is set,
builtins will also be executed but certain special properties of them
are suppressed. The <code>-p</code> flag causes a default path to be searched
instead of that in <code>$path</code>. With the <code>-v</code> flag, <code>command</code> is similar to
<code>whence</code> and with <code>-V</code>, it is equivalent to <code>whence -v</code>.</p>
<p><span id="index-exec"></span></p>
<p><code>exec</code> [ <code>-cl</code> ] [ <code>-a</code> <code>argv0</code> ]</p>
<p>The following command together with any arguments is run in place of the
current process, rather than as a sub-process. The shell does not fork
and is replaced. The shell does not invoke <code>TRAPEXIT</code>, nor does it
source <code>zlogout</code> files. The options are provided for compatibility with
other shells.</p>
<p>The <code>-c</code> option clears the environment.</p>
<p>The <code>-l</code> option is equivalent to the <code>-</code> precommand modifier, to treat
the replacement command as a login shell; the command is executed with a
<code>-</code> prepended to its <code>argv[0]</code> string. This flag has no effect if used
together with the <code>-a</code> option.</p>
<p>The <code>-a</code> option is used to specify explicitly the <code>argv[0]</code> string (the
name of the command as seen by the process itself) to be used by the
replacement command and is directly equivalent to setting a value for
the <code>ARGV0</code> environment variable.</p>
<p><span id="index-nocorrect"></span></p>
<p><code>nocorrect</code></p>
<p>Spelling correction is not done on any of the words. This must appear
before any other precommand modifier, as it is interpreted immediately,
before any parsing is done. It has no effect in non-interactive shells.</p>
<p><span id="index-noglob"></span></p>
<p><code>noglob</code></p>
<p>Filename generation (globbing) is not performed on any of the words.</p>
<hr />
<p><span id="Complex-Commands"></span>
<span id="Complex-Commands-1"></span></p>
<h2 id="63-complex-commands"><a class="header" href="#63-complex-commands">6.3 Complex Commands</a></h2>
<p><span id="index-complex-commands"></span>
<span id="index-commands_002c-complex"></span></p>
<p>A <em>complex command</em> in zsh is one of the following:</p>
<p><span id="index-if"></span> <span id="index-if-construct"></span></p>
<p><code>if</code> <code>list</code> <code>then</code> <code>list</code> [ <code>elif</code> <code>list</code> <code>then</code> <code>list</code> ] ... [
<code>else</code> <code>list</code> ] <code>fi</code></p>
<p>The <code>if</code> <code>list</code> is executed, and if it returns a zero exit status, the
<code>then</code> <code>list</code> is executed. Otherwise, the <code>elif</code> <code>list</code> is executed and
if its status is zero, the <code>then</code> <code>list</code> is executed. If each <code>elif</code>
<code>list</code> returns nonzero status, the <code>else</code> <code>list</code> is executed.</p>
<p><span id="index-for"></span> <span id="index-for-loops"></span>
<span id="index-loops_002c-for"></span></p>
<p><code>for</code> <code>name</code> ... [ <code>in</code> <code>word</code> ... ] <code>term</code> <code>do</code> <code>list</code> <code>done</code></p>
<p>Expand the list of <code>word</code>s, and set the parameter <code>name</code> to each of them
in turn, executing <code>list</code> each time. If the ‘<code>in</code> <code>word</code>’ is omitted,
use the positional parameters instead of the <code>word</code>s.</p>
<p>The <code>term</code> consists of one or more newline or <code>;</code> which terminate the
<code>word</code>s, and are optional when the ‘<code>in</code> <code>word</code>’ is omitted.</p>
<p>More than one parameter <code>name</code> can appear before the list of <code>word</code>s. If
<code>N</code> <code>name</code>s are given, then on each execution of the loop the next <code>N</code>
<code>word</code>s are assigned to the corresponding parameters. If there are more
<code>name</code>s than remaining <code>word</code>s, the remaining parameters are each set to
the empty string. Execution of the loop ends when there is no remaining
<code>word</code> to assign to the first <code>name</code>. It is only possible for <code>in</code> to
appear as the first <code>name</code> in the list, else it will be treated as
marking the end of the list.</p>
<p><code>for ((</code> [<code>expr1</code>] <code>;</code> [<code>expr2</code>] <code>;</code> [<code>expr3</code>] <code>)) do</code> <code>list</code>
<code>done</code></p>
<p>The arithmetic expression <code>expr1</code> is evaluated first (see <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a>). The
arithmetic expression <code>expr2</code> is repeatedly evaluated until it evaluates
to zero and when non-zero, <code>list</code> is executed and the arithmetic
expression <code>expr3</code> evaluated. If any expression is omitted, then it
behaves as if it evaluated to 1.</p>
<p><span id="index-while"></span> <span id="index-while-loops"></span>
<span id="index-loops_002c-while"></span></p>
<p><code>while</code> <code>list</code> <code>do</code> <code>list</code> <code>done</code></p>
<p>Execute the <code>do</code> <code>list</code> as long as the <code>while</code> <code>list</code> returns a zero
exit status.</p>
<p><span id="index-until"></span> <span id="index-until-loops"></span>
<span id="index-loops_002c-until"></span></p>
<p><code>until</code> <code>list</code> <code>do</code> <code>list</code> <code>done</code></p>
<p>Execute the <code>do</code> <code>list</code> as long as <code>until</code> <code>list</code> returns a nonzero exit
status.</p>
<p><span id="index-repeat"></span> <span id="index-repeat-loops"></span>
<span id="index-loops_002c-repeat"></span></p>
<p><code>repeat</code> <code>word</code> <code>do</code> <code>list</code> <code>done</code></p>
<p><code>word</code> is expanded and treated as an arithmetic expression, which must
evaluate to a number <code>n</code>. <code>list</code> is then executed <code>n</code> times.</p>
<p>The <code>repeat</code> syntax is disabled by default when the shell starts in a
mode emulating another shell. It can be enabled with the command
‘<code>enable -r repeat</code>’</p>
<p><span id="index-case"></span> <span id="index-case-selection"></span>
<span id="index-selection_002c-case"></span></p>
<p><code>case</code> <code>word</code> <code>in</code> [ [<code>(</code>] <code>pattern</code> [ <code>|</code> <code>pattern</code> ] ... <code>)</code>
<code>list</code> (<code>;;</code>|<code>;&amp;</code>|<code>;|</code>) ] ... <code>esac</code></p>
<p>Execute the <code>list</code> associated with the first <code>pattern</code> that matches
<code>word</code>, if any. The form of the patterns is the same as that used for
filename generation. See <a href="Expansion.html#Filename-Generation">Filename
Generation</a>.</p>
<p>Note further that, unless the <code>SH_GLOB</code> option is set, the whole pattern
with alternatives is treated by the shell as equivalent to a group of
patterns within parentheses, although white space may appear about the
parentheses and the vertical bar and will be stripped from the pattern
at those points. White space may appear elsewhere in the pattern; this
is not stripped. If the <code>SH_GLOB</code> option is set, so that an opening
parenthesis can be unambiguously treated as part of the case syntax, the
expression is parsed into separate words and these are treated as strict
alternatives (as in other shells).</p>
<p>If the <code>list</code> that is executed is terminated with <code>;&amp;</code> rather than <code>;;</code>,
the following list is also executed. The rule for the terminator of the
following list <code>;;</code>, <code>;&amp;</code> or <code>;|</code> is applied unless the <code>esac</code> is
reached.</p>
<p>If the <code>list</code> that is executed is terminated with <code>;|</code> the shell
continues to scan the <code>pattern</code>s looking for the next match, executing
the corresponding <code>list</code>, and applying the rule for the corresponding
terminator <code>;;</code>, <code>;&amp;</code> or <code>;|</code>. Note that <code>word</code> is not re-expanded; all
applicable <code>pattern</code>s are tested with the same <code>word</code>.</p>
<p><span id="index-select"></span> <span id="index-user-selection"></span>
<span id="index-selection_002c-user"></span></p>
<p><code>select</code> <code>name</code> [ <code>in</code> <code>word</code> ... <code>term</code> ] <code>do</code> <code>list</code> <code>done</code></p>
<p>where <code>term</code> is one or more newline or <code>;</code> to terminate the <code>word</code>s.
<span id="index-REPLY_002c-use-of"></span> Print the set of <code>word</code>s,
each preceded by a number. If the <code>in</code> <code>word</code> is omitted, use the
positional parameters. The <code>PROMPT3</code> prompt is printed and a line is
read from the line editor if the shell is interactive and that is
active, or else standard input. If this line consists of the number of
one of the listed <code>word</code>s, then the parameter <code>name</code> is set to the
<code>word</code> corresponding to this number. If this line is empty, the
selection list is printed again. Otherwise, the value of the parameter
<code>name</code> is set to null. The contents of the line read from standard input
is saved in the parameter <code>REPLY</code>. <code>list</code> is executed for each selection
until a break or end-of-file is encountered.</p>
<p><span id="index-subshell"></span></p>
<p><code>(</code> <code>list</code> <code>)</code></p>
<p>Execute <code>list</code> in a subshell. Traps set by the <code>trap</code> builtin are reset
to their default values while executing <code>list</code>.</p>
<p><code>{</code> <code>list</code> <code>}</code></p>
<p>Execute <code>list</code>.</p>
<p><span id="index-always"></span> <span id="index-always-blocks"></span>
<span id="index-try-blocks"></span></p>
<p><code>{</code> <code>try-list</code> <code>} always {</code> <code>always-list</code> <code>}</code></p>
<p>First execute <code>try-list</code>. Regardless of errors, or <code>break</code> or <code>continue</code>
commands encountered within <code>try-list</code>, execute <code>always-list</code>. Execution
then continues from the result of the execution of <code>try-list</code>; in other
words, any error, or <code>break</code> or <code>continue</code> command is treated in the
normal way, as if <code>always-list</code> were not present. The two chunks of code
are referred to as the ‘try block’ and the ‘always block’.</p>
<p>Optional newlines or semicolons may appear after the <code>always</code>; note,
however, that they may <em>not</em> appear between the preceding closing brace
and the <code>always</code>.</p>
<p>An ‘error’ in this context is a condition such as a syntax error which
causes the shell to abort execution of the current function, script, or
list. Syntax errors encountered while the shell is parsing the code do
not cause the <code>always-list</code> to be executed. For example, an erroneously
constructed <code>if</code> block in <code>try-list</code> would cause the shell to abort
during parsing, so that <code>always-list</code> would not be executed, while an
erroneous substitution such as <code>${*foo*}</code> would cause a run-time error,
after which <code>always-list</code> would be executed.</p>
<p>An error condition can be tested and reset with the special integer
variable <code>TRY_BLOCK_ERROR</code>. Outside an <code>always-list</code> the value is
irrelevant, but it is initialised to <code>-1</code>. Inside <code>always-list</code>, the
value is 1 if an error occurred in the <code>try-list</code>, else 0. If
<code>TRY_BLOCK_ERROR</code> is set to 0 during the <code>always-list</code>, the error
condition caused by the <code>try-list</code> is reset, and shell execution
continues normally after the end of <code>always-list</code>. Altering the value
during the <code>try-list</code> is not useful (unless this forms part of an
enclosing <code>always</code> block).</p>
<p>Regardless of <code>TRY_BLOCK_ERROR</code>, after the end of <code>always-list</code> the
normal shell status <code>$?</code> is the value returned from <code>try-list</code>. This
will be non-zero if there was an error, even if <code>TRY_BLOCK_ERROR</code> was
set to zero.</p>
<p>The following executes the given code, ignoring any errors it causes.
This is an alternative to the usual convention of protecting code by
executing it in a subshell.</p>
<div class="example">
<pre><code class="language-example">{
# code which may cause an error
} always {
# This code is executed regardless of the error.
(( TRY_BLOCK_ERROR = 0 ))
}
# The error condition has been reset.
</code></pre>
</div>
<p>When a <code>try</code> block occurs outside of any function, a <code>return</code> or a
<code>exit</code> encountered in <code>try-list</code> does <em>not</em> cause the execution of
<code>always-list</code>. Instead, the shell exits immediately after any <code>EXIT</code>
trap has been executed. Otherwise, a <code>return</code> command encountered in
<code>try-list</code> will cause the execution of <code>always-list</code>, just like <code>break</code>
and <code>continue</code>.</p>
<p><span id="index-function"></span></p>
<p><code>function</code> <code>word</code> ... [ <code>()</code> ] [ <code>term</code> ] <code>{</code> <code>list</code> <code>}</code></p>
<p><code>word</code> ... <code>()</code> [ <code>term</code> ] <code>{</code> <code>list</code> <code>}</code></p>
<p><code>word</code> ... <code>()</code> [ <code>term</code> ] <code>command</code></p>
<p>where <code>term</code> is one or more newline or <code>;</code>. Define a function which is
referenced by any one of <code>word</code>. Normally, only one <code>word</code> is provided;
multiple <code>word</code>s are usually only useful for setting traps. The body of
the function is the <code>list</code> between the <code>{</code> and <code>}</code>. See
<a href="Functions.html#Functions">Functions</a>.</p>
<p>If the option <code>SH_GLOB</code> is set for compatibility with other shells, then
whitespace may appear between the left and right parentheses when there
is a single <code>word</code>; otherwise, the parentheses will be treated as
forming a globbing pattern in that case.</p>
<p>In any of the forms above, a redirection may appear outside the function
body, for example</p>
<div class="example">
<pre><code class="language-example">func() { ... } 2&gt;&amp;1
</code></pre>
</div>
<p>The redirection is stored with the function and applied whenever the
function is executed. Any variables in the redirection are expanded at
the point the function is executed, but outside the function scope.</p>
<p><span id="index-timing"></span> <span id="index-time"></span></p>
<p><code>time</code> [ <code>pipeline</code> ]</p>
<p>The <code>pipeline</code> is executed, and timing statistics are reported on the
standard error in the form specified by the <code>TIMEFMT</code> parameter. If
<code>pipeline</code> is omitted, print statistics about the shell process and its
children.</p>
<p><span id="index-conditional-expression"></span>
<span id="index-_005b_005b"></span></p>
<p><code>[[</code> <code>exp</code> <code>]]</code></p>
<p>Evaluates the conditional expression <code>exp</code> and return a zero exit status
if it is true. See <a href="Conditional-Expressions.html#Conditional-Expressions">Conditional
Expressions</a> for a
description of <code>exp</code>.</p>
<hr />
<p><span id="Alternate-Forms-For-Complex-Commands"></span>
<span id="Alternate-Forms-For-Complex-Commands-1"></span></p>
<h2 id="64-alternate-forms-for-complex-commands"><a class="header" href="#64-alternate-forms-for-complex-commands">6.4 Alternate Forms For Complex Commands</a></h2>
<p><span id="index-alternate-forms-for-complex-commands"></span>
<span id="index-commands_002c-alternate-forms-for-complex"></span></p>
<p>Many of zsh’s complex commands have alternate forms. These are
non-standard and are likely not to be obvious even to seasoned shell
programmers; they should not be used anywhere that portability of shell
code is a concern.</p>
<p>The short versions below only work if <code>sublist</code> is of the form ‘<code>{</code>
<code>list</code> <code>}</code>’ or if the <code>SHORT_LOOPS</code> option is set. For the <code>if</code>, <code>while</code>
and <code>until</code> commands, in both these cases the test part of the loop must
also be suitably delimited, such as by ‘<code>[[</code> <code>...</code> <code>]]</code>’ or ‘<code>((</code> <code>...</code>
<code>))</code>’, else the end of the test will not be recognized. For the <code>for</code>,
<code>repeat</code>, <code>case</code> and <code>select</code> commands no such special form for the
arguments is necessary, but the other condition (the special form of
<code>sublist</code> or use of the <code>SHORT_LOOPS</code> option) still applies.</p>
<ul>
<li>
<p><code>if</code> <code>list</code> <code>{</code> <code>list</code> <code>}</code> [ <code>elif</code> <code>list</code> <code>{</code> <code>list</code> <code>}</code> ] ... [
<code>else {</code> <code>list</code> <code>}</code> ]<br />
An alternate form of <code>if</code>. The rules mean that</p>
<div class="example">
<pre><code class="language-example">if [[ -o ignorebraces ]] {
print yes
}
</code></pre>
</div>
<p>works, but</p>
<div class="example">
<pre><code class="language-example">if true { # Does not work!
print yes
}
</code></pre>
</div>
<p>does <em>not</em>, since the test is not suitably delimited.</p>
</li>
<li>
<p><code>if</code> <code>list</code> <code>sublist</code><br />
A short form of the alternate <code>if</code>. The same limitations on the form
of <code>list</code> apply as for the previous form.</p>
</li>
<li>
<p><code>for</code> <code>name</code> ... <code>(</code> <code>word</code> ... <code>)</code> <code>sublist</code><br />
A short form of <code>for</code>.</p>
</li>
<li>
<p><code>for</code> <code>name</code> ... [ <code>in</code> <code>word</code> ... ] <code>term</code> <code>sublist</code><br />
where <code>term</code> is at least one newline or <code>;</code>. Another short form of
<code>for</code>.</p>
</li>
<li>
<p><code>for ((</code> [<code>expr1</code>] <code>;</code> [<code>expr2</code>] <code>;</code> [<code>expr3</code>] <code>))</code>
<code>sublist</code><br />
A short form of the arithmetic <code>for</code> command.</p>
<p><span id="index-foreach"></span></p>
</li>
<li>
<p><code>foreach</code> <code>name</code> ... <code>(</code> <code>word</code> ... <code>)</code> <code>list</code> <code>end</code><br />
Another form of <code>for</code>.</p>
</li>
<li>
<p><code>while</code> <code>list</code> <code>{</code> <code>list</code> <code>}</code><br />
An alternative form of <code>while</code>. Note the limitations on the form of
<code>list</code> mentioned above.</p>
</li>
<li>
<p><code>until</code> <code>list</code> <code>{</code> <code>list</code> <code>}</code><br />
An alternative form of <code>until</code>. Note the limitations on the form of
<code>list</code> mentioned above.</p>
</li>
<li>
<p><code>repeat</code> <code>word</code> <code>sublist</code><br />
This is a short form of <code>repeat</code>.</p>
</li>
<li>
<p><code>case</code> <code>word</code> <code>{</code> [ [<code>(</code>] <code>pattern</code> [ <code>|</code> <code>pattern</code> ] ... <code>)</code>
<code>list</code> (<code>;;</code>|<code>;&amp;</code>|<code>;|</code>) ] ... <code>}</code><br />
An alternative form of <code>case</code>.</p>
</li>
<li>
<p><code>select</code> <code>name</code> [ <code>in</code> <code>word</code> ... <code>term</code> ] <code>sublist</code><br />
where <code>term</code> is at least one newline or <code>;</code>. A short form of
<code>select</code>.</p>
</li>
<li>
<p><code>function</code> <code>word</code> ... [ <code>()</code> ] [ <code>term</code> ] <code>sublist</code><br />
This is a short form of <code>function</code>.</p>
</li>
</ul>
<hr />
<p><span id="Reserved-Words"></span> <span id="Reserved-Words-1"></span></p>
<h2 id="65-reserved-words"><a class="header" href="#65-reserved-words">6.5 Reserved Words</a></h2>
<p><span id="index-reserved-words"></span>
<span id="index-disable_002c-use-of"></span></p>
<p>The following words are recognized as reserved words when used as the
first word of a command unless quoted or disabled using <code>disable -r</code>:</p>
<p><code>do done esac then elif else fi for case if while function repeat time until select coproc nocorrect foreach end ! [[ { } declare export float integer local readonly typeset</code></p>
<p>Additionally, ‘<code>}</code>’ is recognized in any position if neither the
<code>IGNORE_BRACES</code> option nor the <code>IGNORE_CLOSE_BRACES</code> option is set.</p>
<hr />
<p><span id="Errors"></span> <span id="Errors-1"></span></p>
<h2 id="66-errors"><a class="header" href="#66-errors">6.6 Errors</a></h2>
<p><span id="index-errors_002c-handling-of"></span></p>
<p>Certain errors are treated as fatal by the shell: in an interactive
shell, they cause control to return to the command line, and in a
non-interactive shell they cause the shell to be aborted. In older
versions of zsh, a non-interactive shell running a script would not
abort completely, but would resume execution at the next command to be
read from the script, skipping the remainder of any functions or shell
constructs such as loops or conditions; this somewhat illogical
behaviour can be recovered by setting the option <code>CONTINUE_ON_ERROR</code>.</p>
<p>Fatal errors found in non-interactive shells include:</p>
<ul>
<li>Failure to parse shell options passed when invoking the shell</li>
<li>Failure to change options with the <code>set</code> builtin</li>
<li>Parse errors of all sorts, including failures to parse mathematical
expressions</li>
<li>Failures to set or modify variable behaviour with <code>typeset</code>,
<code>local</code>, <code>declare</code>, <code>export</code>, <code>integer</code>, <code>float</code></li>
<li>Execution of incorrectly positioned loop control structures
(<code>continue</code>, <code>break</code>)</li>
<li>Attempts to use regular expression with no regular expression module
available</li>
<li>Disallowed operations when the <code>RESTRICTED</code> options is set</li>
<li>Failure to create a pipe needed for a pipeline</li>
<li>Failure to create a multio</li>
<li>Failure to autoload a module needed for a declared shell feature</li>
<li>Errors creating command or process substitutions</li>
<li>Syntax errors in glob qualifiers</li>
<li>File generation errors where not caught by the option <code>BAD_PATTERN</code></li>
<li>All bad patterns used for matching within case statements</li>
<li>File generation failures where not caused by <code>NO_MATCH</code> or similar
options</li>
<li>All file generation errors where the pattern was used to create a
multio</li>
<li>Memory errors where detected by the shell</li>
<li>Invalid subscripts to shell variables</li>
<li>Attempts to assign read-only variables</li>
<li>Logical errors with variables such as assignment to the wrong type</li>
<li>Use of invalid variable names</li>
<li>Errors in variable substitution syntax</li>
<li>Failure to convert characters in <code>$’</code>...<code>’</code> expressions</li>
</ul>
<p>If the <code>POSIX_BUILTINS</code> option is set, more errors associated with shell
builtin commands are treated as fatal, as specified by the POSIX
standard.</p>
<hr />
<p><span id="Comments"></span> <span id="Comments-1"></span></p>
<h2 id="67-comments"><a class="header" href="#67-comments">6.7 Comments</a></h2>
<p><span id="index-comments"></span>
<span id="index-INTERACTIVE_005fCOMMENTS_002c-use-of"></span>
<span id="index-histchars_002c-use-of"></span></p>
<p>In non-interactive shells, or in interactive shells with the
<code>INTERACTIVE_COMMENTS</code> option set, a word beginning with the third
character of the <code>histchars</code> parameter (‘<code>#</code>’ by default) causes that
word and all the following characters up to a newline to be ignored.</p>
<hr />
<p><span id="Aliasing"></span> <span id="Aliasing-1"></span></p>
<h2 id="68-aliasing"><a class="header" href="#68-aliasing">6.8 Aliasing</a></h2>
<p><span id="index-aliasing"></span></p>
<p>Every eligible <em>word</em> in the shell input is checked to see if there is
an alias defined for it. If so, it is replaced by the text of the alias
if it is in command position (if it could be the first word of a simple
command), or if the alias is global. If the replacement text ends with a
space, the next word in the shell input is always eligible for purposes
of alias expansion. <span id="index-alias_002c-use-of"></span>
<span id="index-aliases_002c-global"></span> An alias is defined using
the <code>alias</code> builtin; global aliases may be defined using the <code>-g</code> option
to that builtin.</p>
<p>A <em>word</em> is defined as:</p>
<ul>
<li>Any plain string or glob pattern</li>
<li>Any quoted string, using any quoting method (note that the quotes
must be part of the alias definition for this to be eligible)</li>
<li>Any parameter reference or command substitution</li>
<li>Any series of the foregoing, concatenated without whitespace or
other tokens between them</li>
<li>Any reserved word (<code>case</code>, <code>do</code>, <code>else</code>, etc.)</li>
<li>With global aliasing, any command separator, any redirection
operator, and ‘<code>(</code>’ or ‘<code>)</code>’ when not part of a glob pattern</li>
</ul>
<p>Alias expansion is done on the shell input before any other expansion
except history expansion. Therefore, if an alias is defined for the word
<code>foo</code>, alias expansion may be avoided by quoting part of the word, e.g.
<code>\foo</code>. Any form of quoting works, although there is nothing to prevent
an alias being defined for the quoted form such as <code>\foo</code> as well.</p>
<p>When <code>POSIX_ALIASES</code> is set, only plain unquoted strings are eligible
for aliasing. The <code>alias</code> builtin does not reject ineligible aliases,
but they are not expanded.</p>
<p>For use with completion, which would remove an initial backslash
followed by a character that isn’t special, it may be more convenient to
quote the word by starting with a single quote, i.e. <code>’foo</code>; completion
will automatically add the trailing single quote.</p>
<hr />
<p><span id="Alias-difficulties"></span></p>
<h3 id="681-alias-difficulties"><a class="header" href="#681-alias-difficulties">6.8.1 Alias difficulties</a></h3>
<p>Although aliases can be used in ways that bend normal shell syntax, not
every string of non-white-space characters can be used as an alias.</p>
<p>Any set of characters not listed as a word above is not a word, hence no
attempt is made to expand it as an alias, no matter how it is defined
(i.e. via the builtin or the special parameter <code>aliases</code> described in
<a href="Zsh-Modules.html#The-zsh_002fparameter-Module">The zsh/parameter
Module</a>). However, as
noted in the case of <code>POSIX_ALIASES</code> above, the shell does not attempt
to deduce whether the string corresponds to a word at the time the alias
is created.</p>
<p>For example, an expression containing an <code>=</code> at the start of a command
line is an assignment and cannot be expanded as an alias; a lone <code>=</code> is
not an assignment but can only be set as an alias using the parameter,
as otherwise the <code>=</code> is taken part of the syntax of the builtin command.</p>
<p>It is not presently possible to alias the ‘<code>((</code>’ token that introduces
arithmetic expressions, because until a full statement has been parsed,
it cannot be distinguished from two consecutive ‘<code>(</code>’ tokens introducing
nested subshells. Also, if a separator such as <code>&amp;&amp;</code> is aliased, <code>\&amp;&amp;</code>
turns into the two tokens <code>\&amp;</code> and <code>&amp;</code>, each of which may have been
aliased separately. Similarly for <code>\&lt;&lt;</code>, <code>\&gt;|</code>, etc.</p>
<p>There is a commonly encountered problem with aliases illustrated by the
following code:</p>
<div class="example">
<pre><code class="language-example">alias echobar='echo bar'; echobar
</code></pre>
</div>
<p>This prints a message that the command <code>echobar</code> could not be found.
This happens because aliases are expanded when the code is read in; the
entire line is read in one go, so that when <code>echobar</code> is executed it is
too late to expand the newly defined alias. This is often a problem in
shell scripts, functions, and code executed with ‘<code>source</code>’ or ‘<code>.</code>’.
Consequently, use of functions rather than aliases is recommended in
non-interactive code.</p>
<p>Note also the unhelpful interaction of aliases and function definitions:</p>
<div class="example">
<pre><code class="language-example">alias func='noglob func'
func() {
echo Do something with $*
}
</code></pre>
</div>
<p>Because aliases are expanded in function definitions, this causes the
following command to be executed:</p>
<div class="example">
<pre><code class="language-example">noglob func() {
echo Do something with $*
}
</code></pre>
</div>
<p>which defines <code>noglob</code> as well as <code>func</code> as functions with the body
given. To avoid this, either quote the name <code>func</code> or use the
alternative function definition form ‘<code>function func</code>’. Ensuring the
alias is defined after the function works but is problematic if the code
fragment might be re-executed.</p>
<hr />
<p><span id="Quoting"></span> <span id="Quoting-1"></span></p>
<h2 id="69-quoting"><a class="header" href="#69-quoting">6.9 Quoting</a></h2>
<p><span id="index-quoting"></span></p>
<p>A character may be <em>quoted</em> (that is, made to stand for itself) by
preceding it with a ‘<code>\</code>’. ‘<code>\</code>’ followed by a newline is ignored.</p>
<p>A string enclosed between ‘<code>$’</code>’ and ‘<code>’</code>’ is processed the same way as
the string arguments of the <code>print</code> builtin, and the resulting string is
considered to be entirely quoted. A literal ‘<code>’</code>’ character can be
included in the string by using the ‘<code>\’</code>’ escape.</p>
<p><span id="index-RC_005fQUOTES_002c-use-of"></span></p>
<p>All characters enclosed between a pair of single quotes (<code>’’</code>) that is
not preceded by a ‘<code>$</code>’ are quoted. A single quote cannot appear within
single quotes unless the option <code>RC_QUOTES</code> is set, in which case a pair
of single quotes are turned into a single quote. For example,</p>
<div class="example">
<pre><code class="language-example">print ''''
</code></pre>
</div>
<p>outputs nothing apart from a newline if <code>RC_QUOTES</code> is not set, but one
single quote if it is set.</p>
<p>Inside double quotes (<code>&quot;&quot;</code>), parameter and command substitution occur,
and ‘<code>\</code>’ quotes the characters ‘<code>\</code>’, ‘<code>‘</code>’, ‘<code>&quot;</code>’, ‘<code>$</code>’, and the
first character of <code>$histchars</code> (default ‘<code>!</code>’).</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Redirection.html#7-redirection">7 Redirection</a>
<ul>
<li><a href="Redirection.html#71-opening-file-descriptors-using-parameters">7.1 Opening file descriptors using parameters</a></li>
<li><a href="Redirection.html#72-multios">7.2 Multios</a></li>
<li><a href="Redirection.html#73-redirections-with-no-command">7.3 Redirections with no command</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Redirection"></span> <span id="Redirection-1"></span></p>
<h1 id="7-redirection"><a class="header" href="#7-redirection">7 Redirection</a></h1>
<p><span id="index-redirection"></span>
<span id="index-file-descriptors"></span>
<span id="index-descriptors_002c-file"></span></p>
<p>If a command is followed by <code>&amp;</code> and job control is not active, then the
default standard input for the command is the empty file <code>/dev/null</code>.
Otherwise, the environment for the execution of a command contains the
file descriptors of the invoking shell as modified by input/output
specifications.</p>
<p>The following may appear anywhere in a simple command or may precede or
follow a complex command. Expansion occurs before <code>word</code> or <code>digit</code> is
used except as noted below. If the result of substitution on <code>word</code>
produces more than one filename, redirection occurs for each separate
filename in turn.</p>
<ul>
<li>
<p><code>&lt;</code> <code>word</code><br />
Open file <code>word</code> for reading as standard input. It is an error to
open a file in this fashion if it does not exist.</p>
</li>
<li>
<p><code>&lt;&gt;</code> <code>word</code><br />
Open file <code>word</code> for reading and writing as standard input. If the
file does not exist then it is created.</p>
</li>
<li>
<p><code>&gt;</code> <code>word</code><br />
Open file <code>word</code> for writing as standard output. If the file does
not exist then it is created. If the file exists, and the <code>CLOBBER</code>
option is unset, this causes an error; otherwise, it is truncated to
zero length.</p>
</li>
<li>
<p><code>&gt;|</code> <code>word</code><br />
<code>&gt;!</code> <code>word</code><br />
Same as <code>&gt;</code>, except that the file is truncated to zero length if it
exists, regardless of <code>CLOBBER</code>.</p>
</li>
<li>
<p><code>&gt;&gt;</code> <code>word</code><br />
Open file <code>word</code> for writing in append mode as standard output. If
the file does not exist, and the <code>CLOBBER</code> and <code>APPEND_CREATE</code>
options are both unset, this causes an error; otherwise, the file is
created.</p>
</li>
<li>
<p><code>&gt;&gt;|</code> <code>word</code><br />
<code>&gt;&gt;!</code> <code>word</code><br />
Same as <code>&gt;&gt;</code>, except that the file is created if it does not exist,
regardless of <code>CLOBBER</code> and <code>APPEND_CREATE</code>.</p>
</li>
<li>
<p><code>&lt;&lt;</code>[<code>-</code>] <code>word</code><br />
The shell input is read up to a line that is the same as <code>word</code>, or
to an end-of-file. No parameter expansion, command substitution or
filename generation is performed on <code>word</code>. The resulting document,
called a <em>here-document</em>, becomes the standard input.</p>
<p>If any character of <code>word</code> is quoted with single or double quotes or
a ‘<code>\</code>’, no interpretation is placed upon the characters of the
document. Otherwise, parameter and command substitution occurs,
‘<code>\</code>’ followed by a newline is removed, and ‘<code>\</code>’ must be used
to quote the characters ‘<code>\</code>’, ‘<code>$</code>’, ‘<code>‘</code>’ and the first character
of <code>word</code>.</p>
<p>Note that <code>word</code> itself does not undergo shell expansion. Backquotes
in <code>word</code> do not have their usual effect; instead they behave
similarly to double quotes, except that the backquotes themselves
are passed through unchanged. (This information is given for
completeness and it is not recommended that backquotes be used.)
Quotes in the form <code>$’``...``’</code> have their standard effect of
expanding backslashed references to special characters.</p>
<p>If <code>&lt;&lt;-</code> is used, then all leading tabs are stripped from <code>word</code> and
from the document.</p>
</li>
<li>
<p><code>&lt;&lt;&lt;</code> <code>word</code><br />
Perform shell expansion on <code>word</code> and pass the result to standard
input. This is known as a <em>here-string</em>. Compare the use of <code>word</code>
in here-documents above, where <code>word</code> does not undergo shell
expansion.</p>
</li>
<li>
<p><code>&lt;&amp;</code> <code>number</code><br />
<code>&gt;&amp;</code> <code>number</code><br />
The standard input/output is duplicated from file descriptor
<code>number</code> (see man page dup2(2)).</p>
</li>
<li>
<p><code>&lt;&amp; -</code><br />
<code>&gt;&amp; -</code><br />
Close the standard input/output.</p>
</li>
<li>
<p><code>&lt;&amp; p</code><br />
<code>&gt;&amp; p</code><br />
The input/output from/to the coprocess is moved to the standard
input/output.</p>
</li>
<li>
<p><code>&gt;&amp;</code> <code>word</code><br />
<code>&amp;&gt;</code> <code>word</code><br />
(Except where ‘<code>&gt;&amp;</code> <code>word</code>’ matches one of the above syntaxes;
‘<code>&amp;&gt;</code>’ can always be used to avoid this ambiguity.) Redirects
both standard output and standard error (file descriptor 2) in the
manner of ‘<code>&gt;</code> <code>word</code>’. Note that this does <em>not</em> have the same
effect as ‘<code>&gt;</code> <code>word</code> <code>2&gt;&amp;1</code>’ in the presence of multios (see the
section below).</p>
</li>
<li>
<p><code>&gt;&amp;|</code> <code>word</code><br />
<code>&gt;&amp;!</code> <code>word</code><br />
<code>&amp;&gt;|</code> <code>word</code><br />
<code>&amp;&gt;!</code> <code>word</code><br />
Redirects both standard output and standard error (file descriptor</p>
<ol start="2">
<li>in the manner of ‘<code>&gt;|</code> <code>word</code>’.</li>
</ol>
</li>
<li>
<p><code>&gt;&gt;&amp;</code> <code>word</code><br />
<code>&amp;&gt;&gt;</code> <code>word</code><br />
Redirects both standard output and standard error (file descriptor</p>
<ol start="2">
<li>in the manner of ‘<code>&gt;&gt;</code> <code>word</code>’.</li>
</ol>
</li>
<li>
<p><code>&gt;&gt;&amp;|</code> <code>word</code><br />
<code>&gt;&gt;&amp;!</code> <code>word</code><br />
<code>&amp;&gt;&gt;|</code> <code>word</code><br />
<code>&amp;&gt;&gt;!</code> <code>word</code><br />
Redirects both standard output and standard error (file descriptor</p>
<ol start="2">
<li>in the manner of ‘<code>&gt;&gt;|</code> <code>word</code>’.</li>
</ol>
</li>
</ul>
<p>If one of the above is preceded by a digit, then the file descriptor
referred to is that specified by the digit instead of the default 0 or</p>
<ol>
<li>The order in which redirections are specified is significant. The
shell evaluates each redirection in terms of the (<em>file descriptor</em>,
<em>file</em>) association at the time of evaluation. For example:</li>
</ol>
<blockquote>
<p>... <code>1&gt;``fname</code> <code>2&gt;&amp;1</code></p>
</blockquote>
<p>first associates file descriptor 1 with file <code>fname</code>. It then associates
file descriptor 2 with the file associated with file descriptor 1 (that
is, <code>fname</code>). If the order of redirections were reversed, file
descriptor 2 would be associated with the terminal (assuming file
descriptor 1 had been) and then file descriptor 1 would be associated
with file <code>fname</code>.</p>
<p>The ‘<code>|&amp;</code>’ command separator described in <a href="Shell-Grammar.html#Simple-Commands-_0026-Pipelines">Simple Commands &amp;
Pipelines</a> is a
shorthand for ‘<code>2&gt;&amp;1 |</code>’.</p>
<p>The various forms of process substitution, ‘<code>&lt;(``list``)</code>’, and
‘<code>=(``list``)</code>’ for input and ‘<code>&gt;(``list``)</code>’ for output, are often
used together with redirection. For example, if <code>word</code> in an output
redirection is of the form ‘<code>&gt;(``list``)</code>’ then the output is piped to
the command represented by <code>list</code>. See <a href="Expansion.html#Process-Substitution">Process
Substitution</a>.</p>
<hr />
<p><span id="Opening-file-descriptors-using-parameters"></span></p>
<h2 id="71-opening-file-descriptors-using-parameters"><a class="header" href="#71-opening-file-descriptors-using-parameters">7.1 Opening file descriptors using parameters</a></h2>
<p><span id="index-file-descriptors_002c-use-with-parameters"></span>
<span id="index-parameters_002c-for-using-file-descriptors"></span></p>
<p>When the shell is parsing arguments to a command, and the shell option
<code>IGNORE_BRACES</code> is not set, a different form of redirection is allowed:
instead of a digit before the operator there is a valid shell identifier
enclosed in braces. The shell will open a new file descriptor that is
guaranteed to be at least 10 and set the parameter named by the
identifier to the file descriptor opened. No whitespace is allowed
between the closing brace and the redirection character. For example:</p>
<blockquote>
<p>... <code>{myfd}&gt;&amp;1</code></p>
</blockquote>
<p>This opens a new file descriptor that is a duplicate of file descriptor
1 and sets the parameter <code>myfd</code> to the number of the file descriptor,
which will be at least 10. The new file descriptor can be written to
using the syntax <code>&gt;&amp;$myfd</code>. The file descriptor remains open in
subshells</p>
<p>The syntax <code>{``varid``}&gt;&amp;-</code>, for example <code>{myfd}&gt;&amp;-</code>, may be used to
close a file descriptor opened in this fashion. Note that the parameter
given by <code>varid</code> must previously be set to a file descriptor in this
case.</p>
<p>It is an error to open or close a file descriptor in this fashion when
the parameter is readonly. However, it is not an error to read or write
a file descriptor using <code>&lt;&amp;$``param</code> or <code>&gt;&amp;$``param</code> if <code>param</code> is
readonly.</p>
<p>If the option <code>CLOBBER</code> is unset, it is an error to open a file
descriptor using a parameter that is already set to an open file
descriptor previously allocated by this mechanism. Unsetting the
parameter before using it for allocating a file descriptor avoids the
error.</p>
<p>Note that this mechanism merely allocates or closes a file descriptor;
it does not perform any redirections from or to it. It is usually
convenient to allocate a file descriptor prior to use as an argument to
<code>exec</code>. The syntax does not in any case work when used around complex
commands such as parenthesised subshells or loops, where the opening
brace is interpreted as part of a command list to be executed in the
current shell.</p>
<p>The following shows a typical sequence of allocation, use, and closing
of a file descriptor:</p>
<div class="example">
<pre><code class="language-example">integer myfd
exec {myfd}&gt;~/logs/mylogfile.txt
print This is a log message. &gt;&amp;$myfd
exec {myfd}&gt;&amp;-
</code></pre>
</div>
<p>Note that the expansion of the variable in the expression <code>&gt;&amp;$myfd</code>
occurs at the point the redirection is opened. This is after the
expansion of command arguments and after any redirections to the left on
the command line have been processed.</p>
<hr />
<p><span id="Multios"></span></p>
<h2 id="72-multios"><a class="header" href="#72-multios">7.2 Multios</a></h2>
<p><span id="index-multios"></span>
<span id="index-MULTIOS_002c-use-of"></span></p>
<p>If the user tries to open a file descriptor for writing more than once,
the shell opens the file descriptor as a pipe to a process that copies
its input to all the specified outputs, similar to tee, provided the
<code>MULTIOS</code> option is set, as it is by default. Thus:</p>
<div class="example">
<pre><code class="language-example">date &gt;foo &gt;bar
</code></pre>
</div>
<p>writes the date to two files, named ‘<code>foo</code>’ and ‘<code>bar</code>’. Note that a
pipe is an implicit redirection; thus</p>
<div class="example">
<pre><code class="language-example">date &gt;foo | cat
</code></pre>
</div>
<p>writes the date to the file ‘<code>foo</code>’, and also pipes it to cat.</p>
<p>Note that the shell opens all the files to be used in the multio process
immediately, not at the point they are about to be written.</p>
<p>Note also that redirections are always expanded in order. This happens
regardless of the setting of the <code>MULTIOS</code> option, but with the option
in effect there are additional consequences. For example, the meaning of
the expression <code>&gt;&amp;1</code> will change after a previous redirection:</p>
<div class="example">
<pre><code class="language-example">date &gt;&amp;1 &gt;output
</code></pre>
</div>
<p>In the case above, the <code>&gt;&amp;1</code> refers to the standard output at the start
of the line; the result is similar to the <code>tee</code> command. However,
consider:</p>
<div class="example">
<pre><code class="language-example">date &gt;output &gt;&amp;1
</code></pre>
</div>
<p>As redirections are evaluated in order, when the <code>&gt;&amp;1</code> is encountered
the standard output is set to the file <code>output</code> and another copy of the
output is therefore sent to that file. This is unlikely to be what is
intended.</p>
<p>If the <code>MULTIOS</code> option is set, the word after a redirection operator is
also subjected to filename generation (globbing). Thus</p>
<div class="example">
<pre><code class="language-example">: &gt; *
</code></pre>
</div>
<p>will truncate all files in the current directory, assuming there’s at
least one. (Without the <code>MULTIOS</code> option, it would create an empty file
called ‘<code>*</code>’.) Similarly, you can do</p>
<div class="example">
<pre><code class="language-example">echo exit 0 &gt;&gt; *.sh
</code></pre>
</div>
<p>If the user tries to open a file descriptor for reading more than once,
the shell opens the file descriptor as a pipe to a process that copies
all the specified inputs to its output in the order specified, provided
the <code>MULTIOS</code> option is set. It should be noted that each file is opened
immediately, not at the point where it is about to be read: this
behaviour differs from <code>cat</code>, so if strictly standard behaviour is
needed, <code>cat</code> should be used instead.</p>
<p>Thus</p>
<div class="example">
<pre><code class="language-example">sort &lt;foo &lt;fubar
</code></pre>
</div>
<p>or even</p>
<div class="example">
<pre><code class="language-example">sort &lt;f{oo,ubar}
</code></pre>
</div>
<p>is equivalent to ‘<code>cat foo fubar | sort</code>’.</p>
<p>Expansion of the redirection argument occurs at the point the
redirection is opened, at the point described above for the expansion of
the variable in <code>&gt;&amp;$myfd</code>.</p>
<p>Note that a pipe is an implicit redirection; thus</p>
<div class="example">
<pre><code class="language-example">cat bar | sort &lt;foo
</code></pre>
</div>
<p>is equivalent to ‘<code>cat bar foo | sort</code>’ (note the order of the inputs).</p>
<p>If the <code>MULTIOS</code> option is <em>un</em>set, each redirection replaces the
previous redirection for that file descriptor. However, all files
redirected to are actually opened, so</p>
<div class="example">
<pre><code class="language-example">echo Hello &gt; bar &gt; baz
</code></pre>
</div>
<p>when <code>MULTIOS</code> is unset will truncate ‘<code>bar</code>’, and write ‘<code>Hello</code>’ into
‘<code>baz</code>’.</p>
<p>There is a problem when an output multio is attached to an external
program. A simple example shows this:</p>
<div class="example">
<pre><code class="language-example">cat file &gt;file1 &gt;file2
cat file1 file2
</code></pre>
</div>
<p>Here, it is possible that the second ‘<code>cat</code>’ will not display the full
contents of <code>file1</code> and <code>file2</code> (i.e. the original contents of <code>file</code>
repeated twice).</p>
<p>The reason for this is that the multios are spawned after the <code>cat</code>
process is forked from the parent shell, so the parent shell does not
wait for the multios to finish writing data. This means the command as
shown can exit before <code>file1</code> and <code>file2</code> are completely written. As a
workaround, it is possible to run the <code>cat</code> process as part of a job in
the current shell:</p>
<div class="example">
<pre><code class="language-example">{ cat file } &gt;file &gt;file2
</code></pre>
</div>
<p>Here, the <code>{``...``}</code> job will pause to wait for both files to be
written.</p>
<hr />
<p><span id="Redirections-with-no-command"></span></p>
<h2 id="73-redirections-with-no-command"><a class="header" href="#73-redirections-with-no-command">7.3 Redirections with no command</a></h2>
<p>When a simple command consists of one or more redirection operators and
zero or more parameter assignments, but no command name, zsh can behave
in several ways.</p>
<p><span id="index-NULLCMD_002c-use-of"></span>
<span id="index-CSH_005fNULLCMD_002c-use-of"></span></p>
<p>If the parameter <code>NULLCMD</code> is not set or the option <code>CSH_NULLCMD</code> is
set, an error is caused. This is the csh behavior and <code>CSH_NULLCMD</code> is
set by default when emulating csh.</p>
<p><span id="index-SH_005fNULLCMD_002c-use-of"></span></p>
<p>If the option <code>SH_NULLCMD</code> is set, the builtin ‘<code>:</code>’ is inserted as a
command with the given redirections. This is the default when emulating
sh or ksh.</p>
<p><span id="index-READNULLCMD_002c-use-of"></span></p>
<p>Otherwise, if the parameter <code>NULLCMD</code> is set, its value will be used as
a command with the given redirections. If both <code>NULLCMD</code> and
<code>READNULLCMD</code> are set, then the value of the latter will be used instead
of that of the former when the redirection is an input. The default for
<code>NULLCMD</code> is ‘<code>cat</code>’ and for <code>READNULLCMD</code> is ‘<code>more</code>’. Thus</p>
<div class="example">
<pre><code class="language-example">&lt; file
</code></pre>
</div>
<p>shows the contents of <code>file</code> on standard output, with paging if that is
a terminal. <code>NULLCMD</code> and <code>READNULLCMD</code> may refer to shell functions.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Command-Execution.html#8-command-execution">8 Command Execution</a></li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Command-Execution"></span>
<span id="Command-Execution-1"></span></p>
<h1 id="8-command-execution"><a class="header" href="#8-command-execution">8 Command Execution</a></h1>
<p><span id="index-command-execution"></span>
<span id="index-execution_002c-of-commands"></span>
<span id="index-command-not-found_002c-handling-of"></span>
<span id="index-command_005fnot_005ffound_005fhandler"></span></p>
<p>If a command name contains no slashes, the shell attempts to locate it.
If there exists a shell function by that name, the function is invoked
as described in <a href="Functions.html#Functions">Functions</a>. If there exists a
shell builtin by that name, the builtin is invoked.</p>
<p><span id="index-path_002c-use-of"></span></p>
<p>Otherwise, the shell searches each element of <code>$path</code> for a search is
unsuccessful, the shell prints an error message and returns a nonzero
exit status.</p>
<p>and the file is not a directory, it is assumed to be a shell script.
<code>/bin/sh</code> is spawned to execute it. If the program is a file beginning
with ‘<code>#!</code>’, the remainder of the first line specifies an interpreter
for the program. The shell will execute the specified interpreter on
operating systems that do</p>
<p>If no external command is found but a function
<code>command_not_found_handler</code> exists the shell executes this function with
all command line arguments. The return status of the function becomes
the status of the command. If the function wishes to mimic the behaviour
of the shell when the command is not found, it should print the message
‘<code>command not found:</code> <code>cmd</code>’ to standard error and return status 127.
Note that the handler is executed in a subshell forked to execute an
external command, hence changes to directories, shell parameters, etc.
have no effect on the main shell.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Functions.html#9-functions">9 Functions</a>
<ul>
<li><a href="Functions.html#91-autoloading-functions">9.1 Autoloading Functions</a></li>
<li><a href="Functions.html#92-anonymous-functions">9.2 Anonymous Functions</a></li>
<li><a href="Functions.html#93-special-functions">9.3 Special Functions</a>
<ul>
<li><a href="Functions.html#931-hook-functions">9.3.1 Hook Functions</a></li>
<li><a href="Functions.html#932-trap-functions">9.3.2 Trap Functions</a></li>
</ul>
</li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Functions"></span> <span id="Functions-3"></span></p>
<h1 id="9-functions"><a class="header" href="#9-functions">9 Functions</a></h1>
<p><span id="index-functions"></span>
<span id="index-function_002c-use-of"></span></p>
<p>Shell functions are defined with the <code>function</code> reserved word or the
special syntax ‘<code>funcname</code> <code>()</code>’. Shell functions are read in and stored
internally. Alias names are resolved when the function is read.
Functions are executed like commands with the arguments passed as
positional parameters. (See <a href="Command-Execution.html#Command-Execution">Command
Execution</a>.)</p>
<p>Functions execute in the same process as the caller and share all files
and present working directory with the caller. A trap on <code>EXIT</code> set
inside a function is executed after the function completes in the
environment of the caller.</p>
<p><span id="index-return_002c-use-of"></span></p>
<p>The <code>return</code> builtin is used to return from function calls.</p>
<p><span id="index-functions_002c-use-of"></span></p>
<p>Function identifiers can be listed with the <code>functions</code> builtin.
<span id="index-unfunction_002c-use-of"></span> Functions can be
undefined with the <code>unfunction</code> builtin.</p>
<hr />
<p><span id="Autoloading-Functions"></span></p>
<h2 id="91-autoloading-functions"><a class="header" href="#91-autoloading-functions">9.1 Autoloading Functions</a></h2>
<p><span id="index-autoloading-functions"></span>
<span id="index-functions_002c-autoloading"></span>
<span id="index-autoload_002c-use-of"></span>
<span id="index-fpath_002c-use-of"></span></p>
<p>A function can be marked as <em>undefined</em> using the <code>autoload</code> builtin (or
‘<code>functions -u</code>’ or ‘<code>typeset -fu</code>’). Such a function has no body. When
the function is first executed, the shell searches for its definition
using the elements of the <code>fpath</code> variable. Thus to define functions for
autoloading, a typical sequence is:</p>
<div class="example">
<pre><code class="language-example">fpath=(~/myfuncs $fpath)
autoload myfunc1 myfunc2 ...
</code></pre>
</div>
<p>The usual alias expansion during reading will be suppressed if the
<code>autoload</code> builtin or its equivalent is given the option <code>-U</code>. This is
recommended for the use of functions supplied with the zsh distribution.
<span id="index-zcompile_002c-use-of"></span> Note that for functions
precompiled with the <code>zcompile</code> builtin command the flag <code>-U</code> must be
provided when the <code>.zwc</code> file is created, as the corresponding
information is compiled into the latter.</p>
<p>For each <code>element</code> in <code>fpath</code>, the shell looks for three possible files,
the newest of which is used to load the definition for the function:</p>
<ul>
<li>
<p><code>element``.zwc</code><br />
A file created with the <code>zcompile</code> builtin command, which is
expected to contain the definitions for all functions in the
directory named <code>element</code>. The file is treated in the same manner as
a directory containing files for functions and is searched for the
definition of the function. If the definition is not found, the
search for a definition proceeds with the other two possibilities
described below.</p>
<p>If <code>element</code> already includes a <code>.zwc</code> extension (i.e. the extension
was explicitly given by the user), <code>element</code> is searched for the
definition of the function without comparing its age to that of
other files; in fact, there does not need to be any directory named
<code>element</code> without the suffix. Thus including an element such as
‘<code>/usr/local/funcs.zwc</code>’ in <code>fpath</code> will speed up the search for
functions, with the disadvantage that functions included must be
explicitly recompiled by hand before the shell notices any changes.</p>
</li>
<li>
<p><code>element``/``function``.zwc</code><br />
A file created with <code>zcompile</code>, which is expected to contain the
definition for <code>function</code>. It may include other function definitions
as well, but those are neither loaded nor executed; a file found in
this way is searched <em>only</em> for the definition of <code>function</code>.</p>
</li>
<li>
<p><code>element``/``function</code><br />
A file of zsh command text, taken to be the definition for
<code>function</code>.</p>
</li>
</ul>
<p>In summary, the order of searching is, first, in the <em>parents of</em>
directories in <code>fpath</code> for the newer of either a compiled directory or a
directory in <code>fpath</code>; second, if more than one of these contains a
definition for the function that is sought, the leftmost in the <code>fpath</code>
is chosen; and third, within a directory, the newer of either a compiled
function or an ordinary function definition is used.</p>
<p><span id="index-KSH_005fAUTOLOAD_002c-use-of"></span></p>
<p>If the <code>KSH_AUTOLOAD</code> option is set, or the file contains only a simple
definition of the function, the file’s contents will be executed. This
will normally define the function in question, but may also perform
initialization, which is executed in the context of the function
execution, and may therefore define local parameters. It is an error if
the function is not defined by loading the file.</p>
<p>Otherwise, the function body (with no surrounding ‘<code>funcname``() {``...``}</code>’) is taken to be the complete contents of the file. This
processing of the file results in the function being re-defined, the
function itself is not re-executed. To force the shell to perform
initialization and then call the function defined, the file should
contain initialization code (which will be executed then discarded) in
addition to a complete function definition (which will be retained for
subsequent calls to the function), and a call to the shell function,
including any arguments, at the end.</p>
<p>For example, suppose the autoload file <code>func</code> contains</p>
<div class="example">
<pre><code class="language-example">func() { print This is func; }
print func is initialized
</code></pre>
</div>
<p>then ‘<code>func; func</code>’ with <code>KSH_AUTOLOAD</code> set will produce both messages
on the first call, but only the message ‘<code>This is func</code>’ on the second
and subsequent calls. Without <code>KSH_AUTOLOAD</code> set, it will produce the
initialization message on the first call, and the other message on the
second and subsequent calls.</p>
<p>It is also possible to create a function that is not marked as
autoloaded, but which loads its own definition by searching <code>fpath</code>, by
using ‘<code>autoload -X</code>’ within a shell function. For example, the
following are equivalent:</p>
<div class="example">
<pre><code class="language-example">myfunc() {
autoload -X
}
myfunc args...
</code></pre>
</div>
<p>and</p>
<div class="example">
<pre><code class="language-example">unfunction myfunc # if myfunc was defined
autoload myfunc
myfunc args...
</code></pre>
</div>
<p>In fact, the <code>functions</code> command outputs ‘<code>builtin autoload -X</code>’ as the
body of an autoloaded function. This is done so that</p>
<div class="example">
<pre><code class="language-example">eval &quot;$(functions)&quot;
</code></pre>
</div>
<p>produces a reasonable result. A true autoloaded function can be
identified by the presence of the comment ‘<code># undefined</code>’ in the body,
because all comments are discarded from defined functions.</p>
<p>To load the definition of an autoloaded function <code>myfunc</code> without
executing <code>myfunc</code>, use:</p>
<div class="example">
<pre><code class="language-example">autoload +X myfunc
</code></pre>
</div>
<hr />
<p><span id="Anonymous-Functions"></span></p>
<h2 id="92-anonymous-functions"><a class="header" href="#92-anonymous-functions">9.2 Anonymous Functions</a></h2>
<p><span id="index-anonymous-functions"></span>
<span id="index-functions_002c-anonymous"></span></p>
<p>If no name is given for a function, it is ‘anonymous’ and is handled
specially. Either form of function definition may be used: a ‘<code>()</code>’ with
no preceding name, or a ‘<code>function</code>’ with an immediately following open
brace. The function is executed immediately at the point of definition
and is not stored for future use. The function name is set to
‘<code>(anon)</code>’.</p>
<p>Arguments to the function may be specified as words following the
closing brace defining the function, hence if there are none no
arguments (other than <code>$0</code>) are set. This is a difference from the way
other functions are parsed: normal function definitions may be followed
by certain keywords such as ‘<code>else</code>’ or ‘<code>fi</code>’, which will be treated as
arguments to anonymous functions, so that a newline or semicolon is
needed to force keyword interpretation.</p>
<p>Note also that the argument list of any enclosing script or function is
hidden (as would be the case for any other function called at this
point).</p>
<p>Redirections may be applied to the anonymous function in the same manner
as to a current-shell structure enclosed in braces. The main use of
anonymous functions is to provide a scope for local variables. This is
particularly convenient in start-up files as these do not provide their
own local variable scope.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">variable=outside
function {
local variable=inside
print &quot;I am $variable with arguments $*&quot;
} this and that
print &quot;I am $variable&quot;
</code></pre>
</div>
<p>outputs the following:</p>
<div class="example">
<pre><code class="language-example">I am inside with arguments this and that
I am outside
</code></pre>
</div>
<p>Note that function definitions with arguments that expand to nothing,
for example ‘<code>name=; function $name { ``...`` }</code>’, are not treated
as anonymous functions. Instead, they are treated as normal function
definitions where the definition is silently discarded.</p>
<hr />
<p><span id="Special-Functions"></span></p>
<h2 id="93-special-functions"><a class="header" href="#93-special-functions">9.3 Special Functions</a></h2>
<p>Certain functions, if defined, have special meaning to the shell.</p>
<hr />
<p><span id="Hook-Functions"></span></p>
<h3 id="931-hook-functions"><a class="header" href="#931-hook-functions">9.3.1 Hook Functions</a></h3>
<p><span id="index-functions_002c-hook"></span>
<span id="index-hook-functions"></span></p>
<p>For the functions below, it is possible to define an array that has the
same name as the function with ‘<code>_functions</code>’ appended. Any element in
such an array is taken as the name of a function to execute; it is
executed in the same context and with the same arguments as the basic
function. For example, if <code>$chpwd_functions</code> is an array containing the
values ‘<code>mychpwd</code>’, ‘<code>chpwd_save_dirstack</code>’, then the shell attempts to
execute the functions ‘<code>chpwd</code>’, ‘<code>mychpwd</code>’ and
‘<code>chpwd_save_dirstack</code>’, in that order. Any function that does not
exist is silently ignored. A function found by this mechanism is
referred to elsewhere as a ‘hook function’. An error in any function
causes subsequent functions not to be run. Note further that an error in
a <code>precmd</code> hook causes an immediately following <code>periodic</code> function not
to run (though it may run at the next opportunity).</p>
<p><span id="index-chpwd"></span>
<span id="index-chpwd_005ffunctions"></span></p>
<p><code>chpwd</code></p>
<p>Executed whenever the current working directory is changed.</p>
<p><span id="index-periodic"></span>
<span id="index-periodic_005ffunctions"></span></p>
<p><code>periodic</code></p>
<p><span id="index-PERIOD"></span></p>
<p>If the parameter <code>PERIOD</code> is set, this function is executed every
<code>$PERIOD</code> seconds, just before a prompt. Note that if multiple functions
are defined using the array <code>periodic_functions</code> only one period is
applied to the complete set of functions, and the scheduled time is not
reset if the list of functions is altered. Hence the set of functions is
always called together.</p>
<p><span id="index-precmd"></span>
<span id="index-precmd_005ffunctions"></span></p>
<p><code>precmd</code></p>
<p>Executed before each prompt. Note that precommand functions are not
re-executed simply because the command line is redrawn, as happens, for
example, when a notification about an exiting job is displayed.</p>
<p><span id="index-preexec"></span>
<span id="index-preexec_005ffunctions"></span></p>
<p><code>preexec</code></p>
<p>Executed just after a command has been read and is about to be executed.
If the history mechanism is active (regardless of whether the line was
discarded from the history buffer), the string that the user typed is
passed as the first argument, otherwise it is an empty string. The
actual command that will be executed (including expanded aliases) is
passed in two different forms: the second argument is a single-line,
size-limited version of the command (with things like function bodies
elided); the third argument contains the full text that is being
executed.</p>
<p><span id="index-zshaddhistory"></span>
<span id="index-zshaddhistory_005ffunctions"></span></p>
<p><code>zshaddhistory</code></p>
<p><span id="index-history_002c-hook-when-line-is-saved"></span></p>
<p>Executed when a history line has been read interactively, but before it
is executed. The sole argument is the complete history line (so that any
terminating newline will still be present).</p>
<p>If any of the hook functions returns status 1 (or any non-zero value
other than 2, though this is not guaranteed for future versions of the
shell) the history line will not be saved, although it lingers in the
history until the next line is executed, allowing you to reuse or edit
it immediately.</p>
<p>If any of the hook functions returns status 2 the history line will be
saved on the internal history list, but not written to the history file.
In case of a conflict, the first non-zero status value is taken.</p>
<p>A hook function may call ‘<code>fc -p</code> <code>...</code>’ to switch the history context
so that the history is saved in a different file from the that in the
global <code>HISTFILE</code> parameter. This is handled specially: the history
context is automatically restored after the processing of the history
line is finished.</p>
<p>The following example function works with one of the options
<code>INC_APPEND_HISTORY</code> or <code>SHARE_HISTORY</code> set, in order that the line is
written out immediately after the history entry is added. It first adds
the history line to the normal history with the newline stripped, which
is usually the correct behaviour. Then it switches the history context
so that the line will be written to a history file in the current
directory.</p>
<div class="example">
<pre><code class="language-example">zshaddhistory() {
print -sr -- ${1%%$'\n'}
fc -p .zsh_local_history
}
</code></pre>
</div>
<p><span id="index-zshexit"></span>
<span id="index-zshexit_005ffunctions"></span></p>
<p><code>zshexit</code></p>
<p>Executed at the point where the main shell is about to exit normally.
This is not called by exiting subshells, nor when the <code>exec</code> precommand
modifier is used before an external command. Also, unlike <code>TRAPEXIT</code>, it
is not called when functions exit.</p>
<hr />
<p><span id="Trap-Functions"></span></p>
<h3 id="932-trap-functions"><a class="header" href="#932-trap-functions">9.3.2 Trap Functions</a></h3>
<p>The functions below are treated specially but do not have corresponding
hook arrays.</p>
<ul>
<li>
<p><code>TRAP``NAL</code><br />
<span id="index-signals_002c-trapping"></span>
<span id="index-trapping-signals"></span></p>
<p>If defined and non-null, this function will be executed whenever the
shell catches a signal <code>SIG``NAL</code>, where <code>NAL</code> is a signal name as
specified for the <code>kill</code> builtin. The signal number will be passed
as the first parameter to the function.</p>
<p>If a function of this form is defined and null, the shell and
processes spawned by it will ignore <code>SIG``NAL</code>.</p>
<p>The return status from the function is handled specially. If it is
zero, the signal is assumed to have been handled, and execution
continues normally. Otherwise, the shell will behave as interrupted
except that the return status of the trap is retained.</p>
<p>Programs terminated by uncaught signals typically return the status
128 plus the signal number. Hence the following causes the handler
for <code>SIGINT</code> to print a message, then mimic the usual effect of the
signal.</p>
<div class="example">
<pre><code class="language-example">TRAPINT() {
print &quot;Caught SIGINT, aborting.&quot;
return $(( 128 + $1 ))
}
</code></pre>
</div>
<p>The functions <code>TRAPZERR</code>, <code>TRAPDEBUG</code> and <code>TRAPEXIT</code> are never
executed inside other traps.</p>
<p><span id="index-TRAPDEBUG"></span></p>
</li>
<li>
<p><code>TRAPDEBUG</code><br />
If the option <code>DEBUG_BEFORE_CMD</code> is set (as it is by default),
executed before each command; otherwise executed after each command.
See the description of the <code>trap</code> builtin in <a href="Shell-Builtin-Commands.html#Shell-Builtin-Commands">Shell Builtin
Commands</a> for
details of additional features provided in debug traps.</p>
<p><span id="index-TRAPEXIT"></span></p>
</li>
<li>
<p><code>TRAPEXIT</code><br />
Executed when the shell exits, or when the current function exits if
defined inside a function. The value of <code>$?</code> at the start of
execution is the exit status of the shell or the return status of
the function exiting.</p>
<p><span id="index-TRAPZERR"></span> <span id="index-TRAPERR"></span></p>
</li>
<li>
<p><code>TRAPZERR</code><br />
Executed whenever a command has a non-zero exit status. However, the
function is not executed if the command occurred in a sublist
followed by ‘<code>&amp;&amp;</code>’ or ‘<code>||</code>’; only the final command in a sublist of
this type causes the trap to be executed. The function <code>TRAPERR</code>
acts the same as <code>TRAPZERR</code> on systems where there is no <code>SIGERR</code>
(this is the usual case).</p>
</li>
</ul>
<p><span id="index-trap_002c-use-of"></span></p>
<p>The functions beginning ‘<code>TRAP</code>’ may alternatively be defined with the
<code>trap</code> builtin: this may be preferable for some uses. Setting a trap
with one form removes any trap of the other form for the same signal;
removing a trap in either form removes all traps for the same signal.
The forms</p>
<div class="example">
<pre><code class="language-example">TRAPNAL() {
# code
}
</code></pre>
</div>
<p>(’function traps’) and</p>
<div class="example">
<pre><code class="language-example">trap '
# code
' NAL
</code></pre>
</div>
<p>(’list traps’) are equivalent in most ways, the exceptions being the
following:</p>
<ul>
<li>Function traps have all the properties of normal functions,
appearing in the list of functions and being called with their own
function context rather than the context where the trap was
triggered.</li>
<li>The return status from function traps is special, whereas a return
from a list trap causes the surrounding context to return with the
given status.</li>
<li>Function traps are not reset within subshells, in accordance with
zsh behaviour; list traps are reset, in accordance with POSIX
behaviour.</li>
</ul>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Jobs-_0026-Signals.html#10-jobs--signals">10 Jobs &amp; Signals</a>
<ul>
<li><a href="Jobs-_0026-Signals.html#101-jobs">10.1 Jobs</a></li>
<li><a href="Jobs-_0026-Signals.html#102-signals">10.2 Signals</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Jobs-_0026-Signals"></span>
<span id="Jobs-_0026-Signals-1"></span></p>
<h1 id="10-jobs--signals"><a class="header" href="#10-jobs--signals">10 Jobs &amp; Signals</a></h1>
<hr />
<p><span id="Jobs"></span></p>
<h2 id="101-jobs"><a class="header" href="#101-jobs">10.1 Jobs</a></h2>
<p><span id="index-jobs"></span>
<span id="index-MONITOR_002c-use-of"></span></p>
<p>If the <code>MONITOR</code> option is set, an interactive shell associates a <em>job</em>
with each pipeline. command, and assigns them small integer numbers.
When a job is started asynchronously with ‘<code>&amp;</code>’, the shell prints a line
to standard error which looks like:</p>
<div class="example">
<pre><code class="language-example">[1] 1234
</code></pre>
</div>
<p>indicating that the job which was started asynchronously was job number
1 and had one (top-level) process, whose process ID was 1234.</p>
<p>If a job is started with ‘<code>&amp;|</code>’ or ‘<code>&amp;!</code>’, then that job is immediately
disowned. After startup, it to the job control features described here.</p>
<p>If you are running a job and wish to do something else you may hit the
key ^Z (control-Z) which sends a <code>TSTP</code> signal to the current job: this
key may be redefined by the <code>susp</code> option of the external <code>stty</code>
command. <span id="index-jobs_002c-suspending"></span>
<span id="index-suspending-jobs"></span> The shell will then normally
indicate that the job has been ‘suspended’, and print another prompt.
You can then manipulate the state of this job,
<span id="index-bg_002c-use-of"></span> putting it in the background
with the <code>bg</code> command, or run some other commands and then eventually
bring the job back into the foreground with
<span id="index-fg_002c-use-of"></span> the foreground command <code>fg</code>. A
^Z takes effect immediately and is like an interrupt in that pending
output and unread input are discarded when it is typed.</p>
<p>A job being run in the background will suspend if it tries to read from
the terminal.</p>
<p>Note that if the job running in the foreground is a shell function, then
suspending it will have the effect of causing the shell to fork. This is
necessary to separate the function’s state from that of the parent shell
performing the job control, so that the latter can return to the command
line prompt. As a result, even if <code>fg</code> is used to continue the job the
function will no longer be part of the parent shell, and any variables
set by the function will not be visible in the parent shell. Thus the
behaviour is different from the case where the function was never
suspended. Zsh is different from many other shells in this regard.</p>
<p>One additional side effect is that use of <code>disown</code> with a job created by
suspending shell code in this fashion is delayed: the job can only be
disowned once any process started from the parent shell has terminated.
At that point, the disowned job disappears silently from the job list.</p>
<p>The same behaviour is found when the shell is executing code as the
right hand side of a pipeline or any complex shell construct such as
<code>if</code>, <code>for</code>, etc., in order that the entire block of code can be managed
as a single job. <span id="index-background-jobs_002c-I_002fO"></span>
<span id="index-jobs_002c-background_002c-I_002fO"></span> Background
jobs are normally allowed to produce output, but this can be disabled by
giving the command ‘<code>stty tostop</code>’. If you set this tty option, then
background jobs will suspend when they try to produce output like they
do when they try to read input.</p>
<p>When a command is suspended and continued later with the <code>fg</code> or <code>wait</code>
builtins, zsh restores tty modes that were in effect when it was
suspended. This (intentionally) does not apply if the command is
continued via ‘<code>kill -CONT</code>’, nor when it is continued with <code>bg</code>.</p>
<p><span id="index-jobs_002c-referring-to"></span>
<span id="index-referring-to-jobs"></span></p>
<p>There are several ways to refer to jobs in the shell. A job can be
referred to by the process ID of any process of the job or by one of the
following:</p>
<ul>
<li>
<p><code>%``number</code><br />
The job with the given number.</p>
</li>
<li>
<p><code>%``string</code><br />
The last job whose command line begins with <code>string</code>.</p>
</li>
<li>
<p><code>%?``string</code><br />
The last job whose command line contains <code>string</code>.</p>
</li>
<li>
<p><code>%%</code><br />
Current job.</p>
</li>
<li>
<p><code>%+</code><br />
Equivalent to ‘<code>%%</code>’.</p>
</li>
<li>
<p><code>%-</code><br />
Previous job.</p>
</li>
</ul>
<p>The shell learns immediately whenever a process changes state.
<span id="index-NOTIFY_002c-use-of"></span> It normally informs you
whenever a job becomes blocked so that no further progress is possible.
If the <code>NOTIFY</code> option is not set, it waits until just before it prints
a prompt before it informs you. All such notifications are sent directly
to the terminal, not to the standard output or standard error.</p>
<p>When the monitor mode is on, each background job that completes triggers
any trap set for <code>CHLD</code>.</p>
<p>When you try to leave the shell while jobs are running or suspended, you
will be warned that ‘You have suspended (running) jobs’. You may use the
<code>jobs</code> command to see what they are. If you do this or immediately try
to exit again, the shell will not warn you a second time; the suspended
jobs will be terminated, and the running jobs will be sent a <code>SIGHUP</code>
signal, if the <code>HUP</code> option is set.
<span id="index-HUP_002c-use-of"></span></p>
<p><span id="index-jobs_002c-disowning"></span>
<span id="index-disowning-jobs"></span>
<span id="index-disown_002c-use-of"></span></p>
<p>To avoid having the shell terminate the running jobs, either use the
nohup command (see man page nohup(1)) or the <code>disown</code> builtin.</p>
<hr />
<p><span id="Signals"></span></p>
<h2 id="102-signals"><a class="header" href="#102-signals">10.2 Signals</a></h2>
<p>The <code>INT</code> and <code>QUIT</code> signals for an invoked command are ignored if the
command is followed by ‘<code>&amp;</code>’ and the <code>MONITOR</code> option is not active. The
shell itself always ignores the <code>QUIT</code> signal. Otherwise, signals have
the values inherited by the shell from its parent (but see the
<code>TRAP``NAL</code> special functions in <a href="Functions.html#Functions">Functions</a>).</p>
<p><span id="index-exiting-shell_002c-and-asynchronous-jobs"></span>
<span id="index-asynchronous-jobs_002c-and-exiting-shell"></span>
<span id="index-jobs_002c-asynchronous_002c-and-exiting-shell"></span></p>
<p>Certain jobs are run asynchronously by the shell other than those
explicitly put into the background; even in cases where the shell would
usually wait for such jobs, an explicit <code>exit</code> command or exit due to
the option <code>ERR_EXIT</code> will cause the shell to exit without waiting.
Examples of such asynchronous jobs are process substitution, see
<a href="Expansion.html#Process-Substitution">Process Substitution</a>, and the
handler processes for multios, see the section Multios in
<a href="Redirection.html#Redirection">Redirection</a>.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Arithmetic-Evaluation.html#11-arithmetic-evaluation">11 Arithmetic Evaluation</a></li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Arithmetic-Evaluation"></span>
<span id="Arithmetic-Evaluation-1"></span></p>
<h1 id="11-arithmetic-evaluation"><a class="header" href="#11-arithmetic-evaluation">11 Arithmetic Evaluation</a></h1>
<p><span id="index-arithmetic-evaluation"></span>
<span id="index-evaluation_002c-arithmetic"></span>
<span id="index-let_002c-use-of"></span></p>
<p>The shell can perform integer and floating point arithmetic, either
using the builtin <code>let</code>, or via a substitution of the form
<code>$((``...``))</code>. For integers, the shell is usually compiled to use
8-byte precision where this is available, otherwise precision is 4
bytes. This can be tested, for example, by giving the command ‘<code>print - $(( 12345678901 ))</code>’; if the number appears unchanged, the precision is
at least 8 bytes. Floating point arithmetic always uses the ‘double’
type with whatever corresponding precision is provided by the compiler
and the library.</p>
<p>The <code>let</code> builtin command takes arithmetic expressions as arguments;
each is evaluated separately. Since many of the arithmetic operators, as
well as spaces, require quoting, an alternative form is provided: for
any command which begins with a ‘<code>((</code>’, all the characters until a
matching ‘<code>))</code>’ are treated as a quoted expression and arithmetic
expansion performed as for an argument of <code>let</code>. More precisely,
‘<code>((``...``))</code>’ is equivalent to ‘<code>let &quot;``...``&quot;</code>’. The return status
is 0 if the arithmetic value of the expression is non-zero, 1 if it is
zero, and 2 if an error occurred.</p>
<p>For example, the following statement</p>
<div class="example">
<pre><code class="language-example">(( val = 2 + 1 ))
</code></pre>
</div>
<p>is equivalent to</p>
<div class="example">
<pre><code class="language-example">let &quot;val = 2 + 1&quot;
</code></pre>
</div>
<p>both assigning the value 3 to the shell variable <code>val</code> and returning a
zero status.</p>
<p><span id="index-arithmetic-base"></span>
<span id="index-bases_002c-in-arithmetic"></span></p>
<p>Integers can be in bases other than 10. A leading ‘<code>0x</code>’ or ‘<code>0X</code>’
denotes hexadecimal and a leading ‘<code>0b</code>’ or ‘<code>0B</code>’ binary. Integers may
also be of the form ‘<code>base``#``n</code>’, where <code>base</code> is a decimal number
between two and thirty-six representing the arithmetic base and <code>n</code> is a
number in that base (for example, ‘<code>16#ff</code>’ is 255 in hexadecimal). The
<code>base``#</code> may also be omitted, in which case base 10 is used. For
backwards compatibility the form ‘<code>[``base``]``n</code>’ is also accepted.</p>
<p>An integer expression or a base given in the form ‘<code>base``#``n</code>’ may
contain underscores (‘<code>_</code>’) after the leading digit for visual guidance;
these are ignored in computation. Examples are <code>1_000_000</code> or
<code>0xffff_ffff</code> which are equivalent to <code>1000000</code> and <code>0xffffffff</code>
respectively.</p>
<p>It is also possible to specify a base to be used for output in the form
‘<code>[#``base``]</code>’, for example ‘<code>[#16]</code>’. This is used when outputting
arithmetical substitutions or when assigning to scalar parameters, but
an explicitly defined integer or floating point parameter will not be
affected. If an integer variable is implicitly defined by an arithmetic
expression, any base specified in this way will be set as the variable’s
output arithmetic base as if the option ‘<code>-i</code> <code>base</code>’ to the <code>typeset</code>
builtin had been used. The expression has no precedence and if it occurs
more than once in a mathematical expression, the last encountered is
used. For clarity it is recommended that it appear at the beginning of
an expression. As an example:</p>
<div class="example">
<pre><code class="language-example">typeset -i 16 y
print $(( [#8] x = 32, y = 32 ))
print $x $y
</code></pre>
</div>
<p>outputs first ‘<code>8#40</code>’, the rightmost value in the given output base,
and then ‘<code>8#40 16#20</code>’, because <code>y</code> has been explicitly declared to
have output base 16, while <code>x</code> (assuming it does not already exist) is
implicitly typed by the arithmetic evaluation, where it acquires the
output base 8.</p>
<p>The <code>base</code> may be replaced or followed by an underscore, which may
itself be followed by a positive integer (if it is missing the value 3
is used). This indicates that underscores should be inserted into the
output string, grouping the number for visual clarity. The following
integer specifies the number of digits to group together. For example:</p>
<div class="example">
<pre><code class="language-example">setopt cbases
print $(( [#16_4] 65536 ** 2 ))
</code></pre>
</div>
<p>outputs ‘<code>0x1_0000_0000</code>’.</p>
<p>The feature can be used with floating point numbers, in which case the
base must be omitted; grouping is away from the decimal point. For
example,</p>
<div class="example">
<pre><code class="language-example">zmodload zsh/mathfunc
print $(( [#_] sqrt(1e7) ))
</code></pre>
</div>
<p>outputs ‘<code>3_162.277_660_168_379_5</code>’ (the number of decimal places shown
may vary).</p>
<p><span id="index-C_005fBASES_002c-use-of"></span>
<span id="index-OCTAL_005fZEROES_002c-use-of"></span></p>
<p>If the <code>C_BASES</code> option is set, hexadecimal numbers are output in the
standard C format, for example ‘<code>0xFF</code>’ instead of the usual ‘<code>16#FF</code>’.
If the option <code>OCTAL_ZEROES</code> is also set (it is not by default), octal
numbers will be treated similarly and hence appear as ‘<code>077</code>’ instead of
‘<code>8#77</code>’. This option has no effect on the output of bases other than
hexadecimal and octal, and these formats are always understood on input.</p>
<p>When an output base is specified using the ‘<code>[#``base``]</code>’ syntax, an
appropriate base prefix will be output if necessary, so that the value
output is valid syntax for input. If the <code>#</code> is doubled, for example
‘<code>[##16]</code>’, then no base prefix is output.</p>
<p>Floating point constants are recognized by the presence of a decimal
point or an exponent. The decimal point may be the first character of
the constant, but the exponent character <code>e</code> or <code>E</code> may not, as it will
be taken for a parameter name. All numeric parts (before and after the
decimal point and in the exponent) may contain underscores after the
leading digit for visual guidance; these are ignored in computation.</p>
<p><span id="index-arithmetic-operators"></span>
<span id="index-operators_002c-arithmetic"></span></p>
<p>An arithmetic expression uses nearly the same syntax and associativity
of expressions as in C.</p>
<p>In the native mode of operation, the following operators are supported
(listed in decreasing order of precedence):</p>
<ul>
<li>
<p><code>+ - ! ~ ++ –</code><br />
unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement</p>
</li>
<li>
<p><code>&lt;&lt; &gt;&gt;</code><br />
bitwise shift left, right</p>
</li>
<li>
<p><code>&amp;</code><br />
bitwise AND</p>
</li>
<li>
<p><code>^</code><br />
bitwise XOR</p>
</li>
<li>
<p><code>|</code><br />
bitwise OR</p>
</li>
<li>
<p><code>**</code><br />
exponentiation</p>
</li>
<li>
<p><code>* / %</code><br />
multiplication, division, modulus (remainder)</p>
</li>
<li>
<p><code>+ -</code><br />
addition, subtraction</p>
</li>
<li>
<p><code>&lt; &gt; &lt;= &gt;=</code><br />
comparison</p>
</li>
<li>
<p><code>== !=</code><br />
equality and inequality</p>
</li>
<li>
<p><code>&amp;&amp;</code><br />
logical AND</p>
</li>
<li>
<p><code>|| ^^</code><br />
logical OR, XOR</p>
</li>
<li>
<p><code>? :</code><br />
ternary operator</p>
</li>
<li>
<p><code>= += -= *= /= %= &amp;= ^= |= &lt;&lt;= &gt;&gt;= &amp;&amp;= ||= ^^= **=</code><br />
assignment</p>
</li>
<li>
<p><code>,</code><br />
comma operator</p>
</li>
</ul>
<p>The operators ‘<code>&amp;&amp;</code>’, ‘<code>||</code>’, ‘<code>&amp;&amp;=</code>’, and ‘<code>||=</code>’ are short-circuiting,
and only one of the latter two expressions in a ternary operator is
evaluated. Note the precedence of the bitwise AND, OR, and XOR
operators.</p>
<p>With the option <code>C_PRECEDENCES</code> the precedences (but no other
properties) of the operators are altered to be the same as those in most
other languages that support the relevant operators:</p>
<ul>
<li>
<p><code>+ - ! ~ ++ –</code><br />
unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement</p>
</li>
<li>
<p><code>**</code><br />
exponentiation</p>
</li>
<li>
<p><code>* / %</code><br />
multiplication, division, modulus (remainder)</p>
</li>
<li>
<p><code>+ -</code><br />
addition, subtraction</p>
</li>
<li>
<p><code>&lt;&lt; &gt;&gt;</code><br />
bitwise shift left, right</p>
</li>
<li>
<p><code>&lt; &gt; &lt;= &gt;=</code><br />
comparison</p>
</li>
<li>
<p><code>== !=</code><br />
equality and inequality</p>
</li>
<li>
<p><code>&amp;</code><br />
bitwise AND</p>
</li>
<li>
<p><code>^</code><br />
bitwise XOR</p>
</li>
<li>
<p><code>|</code><br />
bitwise OR</p>
</li>
<li>
<p><code>&amp;&amp;</code><br />
logical AND</p>
</li>
<li>
<p><code>^^</code><br />
logical XOR</p>
</li>
<li>
<p><code>||</code><br />
logical OR</p>
</li>
<li>
<p><code>? :</code><br />
ternary operator</p>
</li>
<li>
<p><code>= += -= *= /= %= &amp;= ^= |= &lt;&lt;= &gt;&gt;= &amp;&amp;= ||= ^^= **=</code><br />
assignment</p>
</li>
<li>
<p><code>,</code><br />
comma operator</p>
</li>
</ul>
<p>Note the precedence of exponentiation in both cases is below that of
unary operators, hence ‘<code>-3**2</code>’ evaluates as ‘<code>9</code>’, not ‘<code>-9</code>’. Use
parentheses where necessary: ‘<code>-(3**2)</code>’. This is for compatibility with
other shells.</p>
<p><span id="index-mathematical-functions_002c-use-of"></span>
<span id="index-functions_002c-math_002c-use-of"></span></p>
<p>Mathematical functions can be called with the syntax
‘<code>func``(``args``)</code>’, where the function decides if the <code>args</code> is
used as a string or a comma-separated list of arithmetic expressions.
The shell currently defines no mathematical functions by default, but
the module <code>zsh/mathfunc</code> may be loaded with the <code>zmodload</code> builtin to
provide standard floating point mathematical functions.</p>
<p>An expression of the form ‘<code>##``x</code>’ where <code>x</code> is any character sequence
such as ‘<code>a</code>’, ‘<code>^A</code>’, or ‘<code>\M-\C-x</code>’ gives the value of this character
and an expression of the form ‘<code>#``name</code>’ gives the value of the first
character of the contents of the parameter <code>name</code>. Character values are
according to the character set used in the current locale; for multibyte
character handling the option <code>MULTIBYTE</code> must be set. Note that this
form is different from ‘<code>$#``name</code>’, a standard parameter substitution
which gives the length of the parameter <code>name</code>. ‘<code>#\</code>’ is accepted
instead of ‘<code>##</code>’, but its use is deprecated.</p>
<p>Named parameters and subscripted arrays can be referenced by name within
an arithmetic expression without using the parameter expansion syntax.
For example,</p>
<div class="example">
<pre><code class="language-example">((val2 = val1 * 2))
</code></pre>
</div>
<p>assigns twice the value of <code>$val1</code> to the parameter named <code>val2</code>.</p>
<p>An internal integer representation of a named parameter can be specified
with the <code>integer</code> builtin.
<span id="index-parameters_002c-integer"></span>
<span id="index-integer-parameters"></span>
<span id="index-integer_002c-use-of"></span> Arithmetic evaluation is
performed on the value of each assignment to a named parameter declared
integer in this manner. Assigning a floating point number to an integer
results in rounding towards zero.</p>
<p><span id="index-parameters_002c-floating-point"></span>
<span id="index-floating-point-parameters"></span>
<span id="index-float_002c-use-of"></span></p>
<p>Likewise, floating point numbers can be declared with the <code>float</code>
builtin; there are two types, differing only in their output format, as
described for the <code>typeset</code> builtin. The output format can be bypassed
by using arithmetic substitution instead of the parameter substitution,
i.e. ‘<code>${``float``}</code>’ uses the defined format, but ‘<code>$((``float``))</code>’
uses a generic floating point format.</p>
<p>Promotion of integer to floating point values is performed where
necessary. In addition, if any operator which requires an integer
(‘<code>&amp;</code>’, ‘<code>|</code>’, ‘<code>^</code>’, ‘<code>&lt;&lt;</code>’, ‘<code>&gt;&gt;</code>’ and their equivalents with
assignment) is given a floating point argument, it will be silently
rounded towards zero except for ‘<code>~</code>’ which rounds down.</p>
<p>Users should beware that, in common with many other programming
languages but not software designed for calculation, the evaluation of
an expression in zsh is taken a term at a time and promotion of integers
to floating point does not occur in terms only containing integers. A
typical result of this is that a division such as <code>6/8</code> is truncated, in
this being rounded towards 0. The <code>FORCE_FLOAT</code> shell option can be used
in scripts or functions where floating point evaluation is required
throughout.</p>
<p>Scalar variables can hold integer or floating point values at different
times; there is no memory of the numeric type in this case.</p>
<p>If a variable is first assigned in a numeric context without previously
being declared, it will be implicitly typed as <code>integer</code> or <code>float</code> and
retain that type either until the type is explicitly changed or until
the end of the scope. This can have unforeseen consequences. For
example, in the loop</p>
<div class="example">
<pre><code class="language-example">for (( f = 0; f &lt; 1; f += 0.1 )); do
# use $f
done
</code></pre>
</div>
<p>if <code>f</code> has not already been declared, the first assignment will cause it
to be created as an integer, and consequently the operation ‘<code>f += 0.1</code>’
will always cause the result to be truncated to zero, so that the loop
will fail. A simple fix would be to turn the initialization into ‘<code>f = 0.0</code>’. It is therefore best to declare numeric variables with explicit
types.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Conditional-Expressions.html#12-conditional-expressions">12 Conditional Expressions</a></li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Conditional-Expressions"></span>
<span id="Conditional-Expressions-1"></span></p>
<h1 id="12-conditional-expressions"><a class="header" href="#12-conditional-expressions">12 Conditional Expressions</a></h1>
<p><span id="index-conditional-expressions"></span>
<span id="index-expressions_002c-conditional"></span></p>
<p>A <em>conditional expression</em> is used with the <code>[[</code> compound command to
test attributes of files and to compare strings. Each expression can be
constructed from one or more of the following unary or binary
expressions:</p>
<ul>
<li>
<p><code>-a</code> <code>file</code><br />
true if <code>file</code> exists.</p>
</li>
<li>
<p><code>-b</code> <code>file</code><br />
true if <code>file</code> exists and is a block special file.</p>
</li>
<li>
<p><code>-c</code> <code>file</code><br />
true if <code>file</code> exists and is a character special file.</p>
</li>
<li>
<p><code>-d</code> <code>file</code><br />
true if <code>file</code> exists and is a directory.</p>
</li>
<li>
<p><code>-e</code> <code>file</code><br />
true if <code>file</code> exists.</p>
</li>
<li>
<p><code>-f</code> <code>file</code><br />
true if <code>file</code> exists and is a regular file.</p>
</li>
<li>
<p><code>-g</code> <code>file</code><br />
true if <code>file</code> exists and has its setgid bit set.</p>
</li>
<li>
<p><code>-h</code> <code>file</code><br />
true if <code>file</code> exists and is a symbolic link.</p>
</li>
<li>
<p><code>-k</code> <code>file</code><br />
true if <code>file</code> exists and has its sticky bit set.</p>
</li>
<li>
<p><code>-n</code> <code>string</code><br />
true if length of <code>string</code> is non-zero.</p>
</li>
<li>
<p><code>-o</code> <code>option</code><br />
true if option named <code>option</code> is on. <code>option</code> may be a single
character, in which case it is a single letter option name. (See
<a href="Options.html#Specifying-Options">Specifying Options</a>.)</p>
<p>When no option named <code>option</code> exists, and the <code>POSIX_BUILTINS</code>
option hasn’t been set, return 3 with a warning. If that option is
set, return 1 with no warning.</p>
</li>
<li>
<p><code>-p</code> <code>file</code><br />
true if <code>file</code> exists and is a FIFO special file (named pipe).</p>
</li>
<li>
<p><code>-r</code> <code>file</code><br />
true if <code>file</code> exists and is readable by current process.</p>
</li>
<li>
<p><code>-s</code> <code>file</code><br />
true if <code>file</code> exists and has size greater than zero.</p>
</li>
<li>
<p><code>-t</code> <code>fd</code><br />
true if file descriptor number <code>fd</code> is open and associated with a
terminal device. (note: <code>fd</code> is not optional)</p>
</li>
<li>
<p><code>-u</code> <code>file</code><br />
true if <code>file</code> exists and has its setuid bit set.</p>
</li>
<li>
<p><code>-v</code> <code>varname</code><br />
true if shell variable <code>varname</code> is set.</p>
</li>
<li>
<p><code>-w</code> <code>file</code><br />
<code>-x</code> <code>file</code><br />
<code>-z</code> <code>string</code><br />
true if length of <code>string</code> is zero.</p>
</li>
<li>
<p><code>-L</code> <code>file</code><br />
true if <code>file</code> exists and is a symbolic link.</p>
</li>
<li>
<p><code>-O</code> <code>file</code><br />
true if <code>file</code> exists and is owned by the effective user ID of this
process.</p>
</li>
<li>
<p><code>-G</code> <code>file</code><br />
true if <code>file</code> exists and its group matches the effective group ID
of this process.</p>
</li>
<li>
<p><code>-S</code> <code>file</code><br />
true if <code>file</code> exists and is a socket.</p>
</li>
<li>
<p><code>-N</code> <code>file</code><br />
true if <code>file</code> exists and its access time is not newer than its
modification time.</p>
</li>
<li>
<p><code>file1</code> <code>-nt</code> <code>file2</code><br />
true if <code>file1</code> exists and is newer than <code>file2</code>.</p>
</li>
<li>
<p><code>file1</code> <code>-ot</code> <code>file2</code><br />
true if <code>file1</code> exists and is older than <code>file2</code>.</p>
</li>
<li>
<p><code>file1</code> <code>-ef</code> <code>file2</code><br />
true if <code>file1</code> and <code>file2</code> exist and refer to the same file.</p>
</li>
<li>
<p><code>string</code> <code>=</code> <code>pattern</code><br />
<code>string</code> <code>==</code> <code>pattern</code><br />
true if <code>string</code> matches <code>pattern</code>. The two forms are exactly
equivalent. The ‘<code>=</code>’ form is the traditional shell syntax (and
hence the only one generally used with the <code>test</code> and <code>[</code> builtins);
the ‘<code>==</code>’ form provides compatibility with other sorts of computer
language.</p>
</li>
<li>
<p><code>string</code> <code>!=</code> <code>pattern</code><br />
true if <code>string</code> does not match <code>pattern</code>.</p>
</li>
<li>
<p><code>string</code> <code>=~</code> <code>regexp</code><br />
true if <code>string</code> matches the regular expression <code>regexp</code>. If the
option <code>RE_MATCH_PCRE</code> is set <code>regexp</code> is tested as a PCRE regular
expression using the <code>zsh/pcre</code> module, else it is tested as a POSIX
extended regular expression using the <code>zsh/regex</code> module. Upon
successful match, some variables will be updated; no variables are
changed if the matching fails.</p>
<p>If the option <code>BASH_REMATCH</code> is not set the scalar parameter <code>MATCH</code>
is set to the substring that matched the pattern and the integer
parameters <code>MBEGIN</code> and <code>MEND</code> to the index of the start and end,
respectively, of the match in <code>string</code>, such that if <code>string</code> is
contained in variable <code>var</code> the expression ‘<code>${var[$MBEGIN,$MEND]}</code>’
is identical to ‘<code>$MATCH</code>’. The setting of the option <code>KSH_ARRAYS</code>
is respected. Likewise, the array <code>match</code> is set to the substrings
that matched parenthesised subexpressions and the arrays <code>mbegin</code>
and <code>mend</code> to the indices of the start and end positions,
respectively, of the substrings within <code>string</code>. The arrays are not
set if there were no parenthesised subexpressions. For example, if
the string ‘<code>a short string</code>’ is matched against the regular
expression ‘<code>s(...)t</code>’, then (assuming the option <code>KSH_ARRAYS</code> is
not set) <code>MATCH</code>, <code>MBEGIN</code> and <code>MEND</code> are ‘<code>short</code>’, <code>3</code> and <code>7</code>,
respectively, while <code>match</code>, <code>mbegin</code> and <code>mend</code> are single entry
arrays containing the strings ‘<code>hor</code>’, ‘<code>4</code>’ and ‘<code>6</code>’,
respectively.</p>
<p>If the option <code>BASH_REMATCH</code> is set the array <code>BASH_REMATCH</code> is set
to the substring that matched the pattern followed by the substrings
that matched parenthesised subexpressions within the pattern.</p>
</li>
<li>
<p><code>string1</code> <code>&lt;</code> <code>string2</code><br />
true if <code>string1</code> comes before <code>string2</code> based on ASCII value of
their characters.</p>
</li>
<li>
<p><code>string1</code> <code>&gt;</code> <code>string2</code><br />
true if <code>string1</code> comes after <code>string2</code> based on ASCII value of
their characters.</p>
</li>
<li>
<p><code>exp1</code> <code>-eq</code> <code>exp2</code><br />
true if <code>exp1</code> is numerically equal to <code>exp2</code>. Note that for purely
numeric comparisons use of the <code>((``...``))</code> builtin described in
<a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a> is
more convenient than conditional expressions.</p>
</li>
<li>
<p><code>exp1</code> <code>-ne</code> <code>exp2</code><br />
true if <code>exp1</code> is numerically not equal to <code>exp2</code>.</p>
</li>
<li>
<p><code>exp1</code> <code>-lt</code> <code>exp2</code><br />
true if <code>exp1</code> is numerically less than <code>exp2</code>.</p>
</li>
<li>
<p><code>exp1</code> <code>-gt</code> <code>exp2</code><br />
true if <code>exp1</code> is numerically greater than <code>exp2</code>.</p>
</li>
<li>
<p><code>exp1</code> <code>-le</code> <code>exp2</code><br />
true if <code>exp1</code> is numerically less than or equal to <code>exp2</code>.</p>
</li>
<li>
<p><code>exp1</code> <code>-ge</code> <code>exp2</code><br />
true if <code>exp1</code> is numerically greater than or equal to <code>exp2</code>.</p>
</li>
<li>
<p><code>(</code> <code>exp</code> <code>)</code><br />
true if <code>exp</code> is true.</p>
</li>
<li>
<p><code>!</code> <code>exp</code><br />
true if <code>exp</code> is false.</p>
</li>
<li>
<p><code>exp1</code> <code>&amp;&amp;</code> <code>exp2</code><br />
true if <code>exp1</code> and <code>exp2</code> are both true.</p>
</li>
<li>
<p><code>exp1</code> <code>||</code> <code>exp2</code><br />
true if either <code>exp1</code> or <code>exp2</code> is true.</p>
</li>
</ul>
<p>For compatibility, if there is a single argument that is not
syntactically significant, typically a variable, the condition is
treated as a test for whether the expression expands as a string of
non-zero length. In other words, <code>[[ $var ]]</code> is the same as <code>[[ -n $var ]]</code>. It is recommended that the second, explicit, form be used where
possible.</p>
<p>Normal shell expansion is performed on the <code>file</code>, <code>string</code> and
<code>pattern</code> arguments, but the result of each expansion is constrained to
be a single word, similar to the effect of double quotes.</p>
<p>Filename generation is not performed on any form of argument to
conditions. However, it can be forced in any case where normal shell
expansion is valid and when the option <code>EXTENDED_GLOB</code> is in effect by
using an explicit glob qualifier of the form <code>(#q)</code> at the end of the
string. A normal glob qualifier expression may appear between the ‘<code>q</code>’
and the closing parenthesis; if none appears the expression has no
effect beyond causing filename generation. The results of filename
generation are joined together to form a single word, as with the
results of other forms of expansion.</p>
<p>This special use of filename generation is only available with the <code>[[</code>
syntax. If the condition occurs within the <code>[</code> or <code>test</code> builtin
commands then globbing occurs instead as part of normal command line
expansion before the condition is evaluated. In this case it may
generate multiple words which are likely to confuse the syntax of the
test command.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">[[ -n file*(#qN) ]]
</code></pre>
</div>
<p>produces status zero if and only if there is at least one file in the
current directory beginning with the string ‘<code>file</code>’. The globbing
qualifier <code>N</code> ensures that the expression is empty if there is no
matching file.</p>
<p>Pattern metacharacters are active for the <code>pattern</code> arguments; the
patterns are the same as those used for filename generation, see
<a href="Expansion.html#Filename-Generation">Filename Generation</a>, but there is
no special behaviour of ‘<code>/</code>’ nor initial dots, and no glob qualifiers
are allowed.</p>
<p>In each of the above expressions, if <code>file</code> is of the form
‘<code>/dev/fd/``n</code>’, where <code>n</code> is an integer, then the test applied to the
open file whose descriptor number is <code>n</code>, even if the underlying system
does not support the <code>/dev/fd</code> directory.</p>
<p>In the forms which do numeric comparison, the expressions <code>exp</code> undergo
arithmetic expansion as if they were enclosed in <code>$((``...``))</code>.</p>
<p>For example, the following:</p>
<div class="example">
<pre><code class="language-example">[[ ( -f foo || -f bar ) &amp;&amp; $report = y* ]] &amp;&amp; print File exists.
</code></pre>
</div>
<p>tests if either file <code>foo</code> or file <code>bar</code> exists, and if so, if the value
of the parameter <code>report</code> begins with ‘<code>y</code>’; if the complete condition
is true, the message ‘<code>File exists.</code>’ is printed.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Prompt-Expansion.html#13-prompt-expansion">13 Prompt Expansion</a>
<ul>
<li><a href="Prompt-Expansion.html#131-expansion-of-prompt-sequences">13.1 Expansion of Prompt Sequences</a></li>
<li><a href="Prompt-Expansion.html#132-simple-prompt-escapes">13.2 Simple Prompt Escapes</a>
<ul>
<li><a href="Prompt-Expansion.html#1321-special-characters">13.2.1 Special characters</a></li>
<li><a href="Prompt-Expansion.html#1322-login-information">13.2.2 Login information</a></li>
<li><a href="Prompt-Expansion.html#1323-shell-state">13.2.3 Shell state</a></li>
<li><a href="Prompt-Expansion.html#1324-date-and-time">13.2.4 Date and time</a></li>
<li><a href="Prompt-Expansion.html#1325-visual-effects">13.2.5 Visual effects</a></li>
</ul>
</li>
<li><a href="Prompt-Expansion.html#133-conditional-substrings-in-prompts">13.3 Conditional Substrings in Prompts</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Prompt-Expansion"></span>
<span id="Prompt-Expansion-1"></span></p>
<h1 id="13-prompt-expansion"><a class="header" href="#13-prompt-expansion">13 Prompt Expansion</a></h1>
<hr />
<p><span id="Expansion-of-Prompt-Sequences"></span></p>
<h2 id="131-expansion-of-prompt-sequences"><a class="header" href="#131-expansion-of-prompt-sequences">13.1 Expansion of Prompt Sequences</a></h2>
<p><span id="index-prompt-expansion"></span>
<span id="index-expansion_002c-prompt"></span></p>
<p>Prompt sequences undergo a special form of expansion. This type of
expansion is also available using the <code>-P</code> option to the <code>print</code>
builtin.</p>
<p><span id="index-PROMPT_005fSUBST_002c-use-of"></span></p>
<p>If the <code>PROMPT_SUBST</code> option is set, the prompt string is first
subjected to <em>parameter expansion</em>, <em>command substitution</em> and
<em>arithmetic expansion</em>. See <a href="Expansion.html#Expansion">Expansion</a>.</p>
<p>Certain escape sequences may be recognised in the prompt string.</p>
<p><span id="index-PROMPT_005fBANG_002c-use-of"></span></p>
<p>If the <code>PROMPT_BANG</code> option is set, a ‘<code>!</code>’ in the prompt is replaced by
the current history event number. A literal ‘<code>!</code>’ may then be
represented as ‘<code>!!</code>’.</p>
<p><span id="index-PROMPT_005fPERCENT_002c-use-of"></span></p>
<p>If the <code>PROMPT_PERCENT</code> option is set, certain escape sequences that
start with ‘<code>%</code>’ are expanded. Many escapes are followed by a single
character, although some of these take an optional integer argument that
should appear between the ‘<code>%</code>’ and the next character of the sequence.
More complicated escape sequences are available to provide conditional
expansion.</p>
<hr />
<p><span id="Simple-Prompt-Escapes"></span></p>
<h2 id="132-simple-prompt-escapes"><a class="header" href="#132-simple-prompt-escapes">13.2 Simple Prompt Escapes</a></h2>
<hr />
<p><span id="Special-characters"></span></p>
<h3 id="1321-special-characters"><a class="header" href="#1321-special-characters">13.2.1 Special characters</a></h3>
<ul>
<li>
<p><code>%%</code><br />
A ‘<code>%</code>’.</p>
</li>
<li>
<p><code>%)</code><br />
A ‘<code>)</code>’.</p>
</li>
</ul>
<hr />
<p><span id="Login-information"></span></p>
<h3 id="1322-login-information"><a class="header" href="#1322-login-information">13.2.2 Login information</a></h3>
<ul>
<li>
<p><code>%l</code><br />
The line (tty) the user is logged in on, without ‘<code>/dev/</code>’ prefix.
If the name starts with ‘<code>/dev/tty</code>’, that prefix is stripped.</p>
</li>
<li>
<p><code>%M</code><br />
The full machine hostname.</p>
</li>
<li>
<p><code>%m</code><br />
The hostname up to the first ‘<code>.</code>’. An integer may follow the ‘<code>%</code>’
to specify how many components of the hostname are desired. With a
negative integer, trailing components of the hostname are shown.</p>
</li>
<li>
<p><code>%n</code><br />
<code>$USERNAME</code>.</p>
</li>
<li>
<p><code>%y</code><br />
The line (tty) the user is logged in on, without ‘<code>/dev/</code>’ prefix.
This does not treat ‘<code>/dev/tty</code>’ names specially.</p>
</li>
</ul>
<hr />
<p><span id="Shell-state"></span></p>
<h3 id="1323-shell-state"><a class="header" href="#1323-shell-state">13.2.3 Shell state</a></h3>
<ul>
<li>
<p><code>%#</code><br />
A ‘<code>#</code>’ if the shell is running with privileges, a ‘<code>%</code>’ if not.
Equivalent to ‘<code>%(!.#.%%)</code>’. The definition of ‘privileged’, for
these purposes, is that either the effective user ID is zero, or, if
POSIX.1e capabilities are supported, that capability vectors.</p>
</li>
<li>
<p><code>%?</code><br />
The return status of the last command executed just before the
prompt.</p>
</li>
<li>
<p><code>%_</code><br />
The status of the parser, i.e. the shell constructs (like ‘<code>if</code>’ and
‘<code>for</code>’) that have been started on the command line. If given an
integer number that many strings will be printed; zero or negative
or no integer means print as many as there are. This is most useful
in prompts <code>PS2</code> for continuation lines and <code>PS4</code> for debugging with
the <code>XTRACE</code> option; in the latter case it will also work
non-interactively.</p>
</li>
<li>
<p><code>%^</code><br />
The status of the parser in reverse. This is the same as ‘<code>%_</code>’
other than the order of strings. It is often used in <code>RPS2</code>.</p>
</li>
<li>
<p><code>%d</code><br />
<code>%/</code><br />
Current working directory. If an integer follows the ‘<code>%</code>’, it
specifies a number of trailing components of the current working
directory to show; zero means the whole path. A negative integer
specifies leading components, i.e. <code>%-1d</code> specifies the first
component.</p>
</li>
<li>
<p><code>%~</code><br />
As <code>%d</code> and <code>%/</code>, but if the current working directory starts with
<code>$HOME</code>, that part is replaced by a ‘<code>~</code>’. Furthermore, if it has a
named directory as its prefix, that part is replaced by a ‘<code>~</code>’
followed by the name of the directory, but only if the result is
shorter than the full path; <a href="Expansion.html#Filename-Expansion">Filename
Expansion</a>.</p>
</li>
<li>
<p><code>%e</code><br />
Evaluation depth of the current sourced file, shell function, or
<code>eval</code>. This is incremented or decremented every time the value of
<code>%N</code> is set or reverted to a previous value, respectively. This is
most useful for debugging as part of <code>$PS4</code>.</p>
</li>
<li>
<p><code>%h</code><br />
<code>%!</code><br />
Current history event number.</p>
</li>
<li>
<p><code>%i</code><br />
The line number currently being executed in the script, sourced
file, or shell function given by <code>%N</code>. This is most useful for
debugging as part of <code>$PS4</code>.</p>
</li>
<li>
<p><code>%I</code><br />
The line number currently being executed in the file <code>%x</code>. This is
similar to <code>%i</code>, but the line number is always a line number in the
file where the code was defined, even if the code is a shell
function.</p>
</li>
<li>
<p><code>%j</code><br />
The number of jobs.</p>
</li>
<li>
<p><code>%L</code><br />
The current value of <code>$SHLVL</code>.</p>
</li>
<li>
<p><code>%N</code><br />
The name of the script, sourced file, or shell function that zsh is
currently executing, whichever was started most recently. If there
is none, this is equivalent to the parameter <code>$0</code>. An integer may
follow the ‘<code>%</code>’ to specify a number of trailing path components to
show; zero means the full path. A negative integer specifies leading
components.</p>
</li>
<li>
<p><code>%x</code><br />
The name of the file containing the source code currently being
executed. This behaves as <code>%N</code> except that function and eval command
names are not shown, instead the file where they were defined.</p>
</li>
<li>
<p><code>%c</code><br />
<code>%.</code><br />
<code>%C</code><br />
Trailing component of the current working directory. An integer may
follow the ‘<code>%</code>’ to get more than one component. Unless ‘<code>%C</code>’ is
used, tilde contraction is performed first. These are deprecated as
<code>%c</code> and <code>%C</code> are equivalent to <code>%1~</code> and <code>%1/</code>, respectively, while
explicit positive integers have the same effect as for the latter
two sequences.</p>
</li>
</ul>
<hr />
<p><span id="Date-and-time"></span></p>
<h3 id="1324-date-and-time"><a class="header" href="#1324-date-and-time">13.2.4 Date and time</a></h3>
<ul>
<li>
<p><code>%D</code><br />
The date in <code>yy``-``mm``-``dd</code> format.</p>
</li>
<li>
<p><code>%T</code><br />
Current time of day, in 24-hour format.</p>
</li>
<li>
<p><code>%t</code><br />
<code>%@</code><br />
Current time of day, in 12-hour, am/pm format.</p>
</li>
<li>
<p><code>%*</code><br />
Current time of day in 24-hour format, with seconds.</p>
</li>
<li>
<p><code>%w</code><br />
The date in <code>day``-``dd</code> format.</p>
</li>
<li>
<p><code>%W</code><br />
The date in <code>mm``/``dd``/``yy</code> format.</p>
</li>
<li>
<p><code>%D{``string``}</code><br />
<code>string</code> is formatted using the <code>strftime</code> function. See man page
strftime(3) for more details. Various zsh extensions provide numbers
with no leading zero or space if the number is a single digit:</p>
<ul>
<li>
<p><code>%f</code><br />
a day of the month</p>
</li>
<li>
<p><code>%K</code><br />
the hour of the day on the 24-hour clock</p>
</li>
<li>
<p><code>%L</code><br />
the hour of the day on the 12-hour clock</p>
</li>
</ul>
<p>In addition, if the system supports the POSIX <code>gettimeofday</code> system
call, <code>%.</code> provides decimal fractions of a second since the epoch
with leading zeroes. By default three decimal places are provided,
but a number of digits up to 9 may be given following the <code>%</code>; hence
<code>%6.</code> outputs microseconds, and <code>%9.</code> outputs nanoseconds. (The
latter requires a nanosecond-precision <code>clock_gettime</code>; systems
lacking this will return a value multiplied by the appropriate power
of 10.) A typical example of this is the format ‘<code>%D{%H:%M:%S.%.}</code>’.</p>
<p>The GNU extension <code>%N</code> is handled as a synonym for <code>%9.</code>.</p>
<p>Additionally, the GNU extension that a ‘<code>-</code>’ between the <code>%</code> and the
format character causes a leading zero or space to be stripped is
handled directly by the shell for the format characters <code>d</code>, <code>f</code>,
<code>H</code>, <code>k</code>, <code>l</code>, <code>m</code>, <code>M</code>, <code>S</code> and <code>y</code>; any other format characters
are provided to the system’s strftime(3) with any leading ‘<code>-</code>’
present, so the handling is system dependent. Further GNU (or other)
extensions are also passed to strftime(3) and may work if the system
supports them.</p>
</li>
</ul>
<hr />
<p><span id="Visual-effects"></span></p>
<h3 id="1325-visual-effects"><a class="header" href="#1325-visual-effects">13.2.5 Visual effects</a></h3>
<ul>
<li>
<p><code>%B</code> (<code>%b</code>)<br />
Start (stop) boldface mode.</p>
</li>
<li>
<p><code>%E</code><br />
Clear to end of line.</p>
</li>
<li>
<p><code>%U</code> (<code>%u</code>)<br />
Start (stop) underline mode.</p>
</li>
<li>
<p><code>%S</code> (<code>%s</code>)<br />
Start (stop) standout mode.</p>
</li>
<li>
<p><code>%F</code> (<code>%f</code>)<br />
Start (stop) using a different foreground colour, if supported by
the terminal. The colour may be specified two ways: either as a
numeric argument, as normal, or by a sequence in braces following
the <code>%F</code>, for example <code>%F{red}</code>. In the latter case the values
allowed are as described for the <code>fg</code> <code>zle_highlight</code> attribute;
<a href="Zsh-Line-Editor.html#Character-Highlighting">Character
Highlighting</a>. This
means that numeric colours are allowed in the second format also.</p>
</li>
<li>
<p><code>%K</code> (<code>%k</code>)<br />
Start (stop) using a different bacKground colour. The syntax is
identical to that for <code>%F</code> and <code>%f</code>.</p>
</li>
<li>
<p><code>%{</code>...<code>%}</code><br />
Include a string as a literal escape sequence. The string within the
braces should not change the cursor position. Brace pairs can nest.</p>
<p>A positive numeric argument between the <code>%</code> and the <code>{</code> is treated
as described for <code>%G</code> below.</p>
</li>
<li>
<p><code>%G</code><br />
Within a <code>%{</code>...<code>%}</code> sequence, include a ‘glitch’: that is, assume
that a single character width will be output. This is useful when
outputting characters that otherwise cannot be correctly handled by
the shell, such as the alternate character set on some terminals.
The characters in question can be included within a <code>%{</code>...<code>%}</code>
sequence together with the appropriate number of <code>%G</code> sequences to
indicate the correct width. An integer between the ‘<code>%</code>’ and ‘<code>G</code>’
indicates a character width other than one. Hence <code>%{``seq``%2G%}</code>
outputs <code>seq</code> and assumes it takes up the width of two standard
characters.</p>
<p>Multiple uses of <code>%G</code> accumulate in the obvious fashion; the
position of the <code>%G</code> is unimportant. Negative integers are not
handled.</p>
<p>Note that when prompt truncation is in use it is advisable to divide
up output into single characters within each <code>%{</code>...<code>%}</code> group so
that the correct truncation point can be found.</p>
</li>
</ul>
<hr />
<p><span id="Conditional-Substrings-in-Prompts"></span></p>
<h2 id="133-conditional-substrings-in-prompts"><a class="header" href="#133-conditional-substrings-in-prompts">13.3 Conditional Substrings in Prompts</a></h2>
<ul>
<li>
<p><code>%v</code><br />
<span id="index-psvar_002c-use-of"></span></p>
<p>The value of the first element of the <code>psvar</code> array parameter.
Following the ‘<code>%</code>’ with an integer gives that element of the array.
Negative integers count from the end of the array.</p>
</li>
<li>
<p><code>%(``x``.``true-text``.``false-text``)</code><br />
Specifies a ternary expression. The character following the <code>x</code> is
arbitrary; the same character is used to separate the text for the
‘true’ result from that for the ‘false’ result. This separator may
not appear in the <code>true-text</code>, except as part of a %-escape
sequence. A ‘<code>)</code>’ may appear in the <code>false-text</code> as ‘<code>%)</code>’.
<code>true-text</code> and <code>false-text</code> may both contain arbitrarily-nested
escape sequences, including further ternary expressions.</p>
<p>The left parenthesis may be preceded or followed by a positive
integer <code>n</code>, which defaults to zero. A negative integer will be
multiplied by -1, except as noted below for ‘<code>l</code>’. The test
character <code>x</code> may be any of the following:</p>
<ul>
<li>
<p><code>!</code><br />
True if the shell is running with privileges.</p>
</li>
<li>
<p><code>#</code><br />
True if the effective uid of the current process is <code>n</code>.</p>
</li>
<li>
<p><code>?</code><br />
True if the exit status of the last command was <code>n</code>.</p>
</li>
<li>
<p><code>_</code><br />
True if at least <code>n</code> shell constructs were started.</p>
</li>
<li>
<p><code>C</code><br />
<code>/</code><br />
True if the current absolute path has at least <code>n</code> elements
relative to the root directory, hence <code>/</code> is counted as 0
elements.</p>
</li>
<li>
<p><code>c</code><br />
<code>.</code><br />
<code>~</code><br />
True if the current path, with prefix replacement, has at least
<code>n</code> elements relative to the root directory, hence <code>/</code> is
counted as 0 elements.</p>
</li>
<li>
<p><code>D</code><br />
True if the month is equal to <code>n</code> (January = 0).</p>
</li>
<li>
<p><code>d</code><br />
True if the day of the month is equal to <code>n</code>.</p>
</li>
<li>
<p><code>e</code><br />
True if the evaluation depth is at least <code>n</code>.</p>
</li>
<li>
<p><code>g</code><br />
True if the effective gid of the current process is <code>n</code>.</p>
</li>
<li>
<p><code>j</code><br />
True if the number of jobs is at least <code>n</code>.</p>
</li>
<li>
<p><code>L</code><br />
True if the <code>SHLVL</code> parameter is at least <code>n</code>.</p>
</li>
<li>
<p><code>l</code><br />
True if at least <code>n</code> characters have already been printed on the
current line. When <code>n</code> is negative, true if at least
<code>abs``(``n``)</code> characters remain before the opposite margin
(thus the left margin for <code>RPROMPT</code>).</p>
</li>
<li>
<p><code>S</code><br />
True if the <code>SECONDS</code> parameter is at least <code>n</code>.</p>
</li>
<li>
<p><code>T</code><br />
True if the time in hours is equal to <code>n</code>.</p>
</li>
<li>
<p><code>t</code><br />
True if the time in minutes is equal to <code>n</code>.</p>
</li>
<li>
<p><code>v</code><br />
True if the array <code>psvar</code> has at least <code>n</code> elements.</p>
</li>
<li>
<p><code>V</code><br />
True if element <code>n</code> of the array <code>psvar</code> is set and non-empty.</p>
</li>
<li>
<p><code>w</code><br />
True if the day of the week is equal to <code>n</code> (Sunday = 0).</p>
</li>
</ul>
</li>
<li>
<p><code>%&lt;``string``&lt;</code><br />
<code>%&gt;``string``&gt;</code><br />
<code>%[``xstring``]</code><br />
Specifies truncation behaviour for the remainder of the prompt
string. The third, deprecated, form is equivalent to
‘<code>%``xstringx</code>’, i.e. <code>x</code> may be ‘<code>&lt;</code>’ or ‘<code>&gt;</code>’. The <code>string</code>
will be displayed in place of the truncated portion of any string;
note this does not undergo prompt expansion.</p>
<p>The numeric argument, which in the third form may appear immediately
after the ‘<code>[</code>’, specifies the maximum permitted length of the
various strings that can be displayed in the prompt. In the first
two forms, this numeric argument may be negative, in which case the
truncation length is determined by subtracting the absolute value of
the numeric argument from the number of character positions
remaining on the current prompt line. If this results in a zero or
negative length, a length of 1 is used. In other words, a negative
argument arranges that after truncation at least <code>n</code> characters
remain before the right margin (left margin for <code>RPROMPT</code>).</p>
<p>The forms with ‘<code>&lt;</code>’ truncate at the left of the string, and the
forms with ‘<code>&gt;</code>’ truncate at the right of the string. For example,
if the current directory is ‘<code>/home/pike</code>’, the prompt ‘<code>%8&lt;..&lt;%/</code>’
will expand to ‘<code>..e/pike</code>’. In this string, the terminating
character (‘<code>&lt;</code>’, ‘<code>&gt;</code>’ or ‘<code>]</code>’), or in fact any character, may be
quoted by a preceding ‘<code>\</code>’; note when using <code>print -P</code>, however,
that this must be doubled as the string is also subject to standard
<code>print</code> processing, in addition to any backslashes removed by a
double quoted string: the worst case is therefore ‘<code>print -P &quot;%&lt;\\&lt;&lt;...&quot;</code>’.</p>
<p>If the <code>string</code> is longer than the specified truncation length, it
will appear in full, completely replacing the truncated string.</p>
<p>The part of the prompt string to be truncated runs to the end of the
string, or to the end of the next enclosing group of the ‘<code>%(</code>’
construct, or to the next truncation encountered at the same
grouping level (i.e. truncations inside a ‘<code>%(</code>’ are separate),
which ever comes first. In particular, a truncation with argument
zero (e.g., ‘<code>%&lt;&lt;</code>’) marks the end of the range of the string to be
truncated while turning off truncation from there on. For example,
the prompt ‘<code>%10&lt;...&lt;%~%&lt;&lt;%# </code>’ will print a truncated
representation of the current directory, followed by a ‘<code>%</code>’ or
‘<code>#</code>’, followed by a space. Without the ‘<code>%&lt;&lt;</code>’, those two
characters would be included in the string to be truncated. Note
that ‘<code>%-0&lt;&lt;</code>’ is not equivalent to ‘<code>%&lt;&lt;</code>’ but specifies that the
prompt is truncated at the right margin.</p>
<p>Truncation applies only within each individual line of the prompt,
as delimited by embedded newlines (if any). If the total length of
any line of the prompt after truncation is greater than the terminal
width, or if the part to be truncated contains embedded newlines,
truncation behavior is undefined and may change in a future version
of the shell. Use ‘<code>%-``n``(l.``true-text``.``false-text``)</code>’ to
remove parts of the prompt when the available space is less than
<code>n</code>.</p>
</li>
</ul>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Expansion.html#14-expansion">14 Expansion</a>
<ul>
<li><a href="Expansion.html#141-history-expansion">14.1 History Expansion</a>
<ul>
<li><a href="Expansion.html#1411-overview">14.1.1 Overview</a></li>
<li><a href="Expansion.html#1412-event-designators">14.1.2 Event Designators</a></li>
<li><a href="Expansion.html#1413-word-designators">14.1.3 Word Designators</a></li>
<li><a href="Expansion.html#1414-modifiers">14.1.4 Modifiers</a></li>
</ul>
</li>
<li><a href="Expansion.html#142-process-substitution">14.2 Process Substitution</a></li>
<li><a href="Expansion.html#143-parameter-expansion">14.3 Parameter Expansion</a>
<ul>
<li><a href="Expansion.html#1431-parameter-expansion-flags">14.3.1 Parameter Expansion Flags</a></li>
<li><a href="Expansion.html#1432-rules">14.3.2 Rules</a></li>
<li><a href="Expansion.html#1433-examples">14.3.3 Examples</a></li>
</ul>
</li>
<li><a href="Expansion.html#144-command-substitution">14.4 Command Substitution</a></li>
<li><a href="Expansion.html#145-arithmetic-expansion">14.5 Arithmetic Expansion</a></li>
<li><a href="Expansion.html#146-brace-expansion">14.6 Brace Expansion</a></li>
<li><a href="Expansion.html#147-filename-expansion">14.7 Filename Expansion</a>
<ul>
<li><a href="Expansion.html#1471-dynamic-named-directories">14.7.1 Dynamic named directories</a></li>
<li><a href="Expansion.html#1472-static-named-directories">14.7.2 Static named directories</a></li>
<li><a href="Expansion.html#1473--expansion">14.7.3 ‘=’ expansion</a></li>
<li><a href="Expansion.html#1474-notes">14.7.4 Notes</a></li>
</ul>
</li>
<li><a href="Expansion.html#148-filename-generation">14.8 Filename Generation</a>
<ul>
<li><a href="Expansion.html#1481-glob-operators">14.8.1 Glob Operators</a></li>
<li><a href="Expansion.html#1482-ksh-like-glob-operators">14.8.2 ksh-like Glob Operators</a></li>
<li><a href="Expansion.html#1483-precedence">14.8.3 Precedence</a></li>
<li><a href="Expansion.html#1484-globbing-flags">14.8.4 Globbing Flags</a></li>
<li><a href="Expansion.html#1485-approximate-matching">14.8.5 Approximate Matching</a></li>
<li><a href="Expansion.html#1486-recursive-globbing">14.8.6 Recursive Globbing</a></li>
<li><a href="Expansion.html#1487-glob-qualifiers">14.8.7 Glob Qualifiers</a></li>
</ul>
</li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Expansion"></span> <span id="Expansion-1"></span></p>
<h1 id="14-expansion"><a class="header" href="#14-expansion">14 Expansion</a></h1>
<p><span id="index-expansion"></span></p>
<p>The following types of expansions are performed in the indicated order
in five steps:</p>
<ul>
<li>
<p><em>History Expansion</em><br />
This is performed only in interactive shells.</p>
</li>
<li>
<p><em>Alias Expansion</em><br />
Aliases are expanded immediately before the command line is parsed
as explained in <a href="Shell-Grammar.html#Aliasing">Aliasing</a>.</p>
</li>
<li>
<p><em>Process Substitution</em><br />
<em>Parameter Expansion</em><br />
<em>Command Substitution</em><br />
<em>Arithmetic Expansion</em><br />
<em>Brace Expansion</em><br />
These five are performed in left-to-right fashion. On each argument,
any of the five steps that are needed are performed one after the
other. Hence, for example, all the parts of parameter expansion are
completed before command substitution is started. After these
expansions, all unquoted occurrences of the characters ‘<code>\</code>’,‘<code>’</code>’
and ‘<code>&quot;</code>’ are removed.</p>
</li>
<li>
<p><em>Filename Expansion</em><br />
If the <code>SH_FILE_EXPANSION</code> option is set, the order of expansion is
modified for compatibility with sh and ksh. In that case <em>filename
expansion</em> is performed immediately after <em>alias expansion</em>,
preceding the set of five expansions mentioned above.</p>
<p><span id="index-globbing"></span></p>
</li>
<li>
<p><em>Filename Generation</em><br />
This expansion, commonly referred to as globbing, is always done
last.</p>
</li>
</ul>
<p>The following sections explain the types of expansion in detail.</p>
<hr />
<p><span id="History-Expansion"></span>
<span id="History-Expansion-1"></span></p>
<h2 id="141-history-expansion"><a class="header" href="#141-history-expansion">14.1 History Expansion</a></h2>
<p><span id="index-history"></span>
<span id="index-history-expansion"></span>
<span id="index-expansion_002c-history"></span></p>
<p>History expansion allows you to use words from previous command lines in
the command line you are typing. This simplifies spelling corrections
and the repetition of complicated commands or arguments.</p>
<p><span id="index-HISTSIZE_002c-use-of"></span></p>
<p>Immediately before execution, each command is saved in the history list,
the size of which is controlled by the <code>HISTSIZE</code> parameter. The one
most recent command is always retained in any case. Each saved command
in the history list is called a history <em>event</em> and is assigned a
number, beginning with 1 (one) when the shell starts up. The history
number that you may see in your prompt (see <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>) is the number that
is to be assigned to the <em>next</em> command.</p>
<hr />
<p><span id="Overview"></span> <span id="Overview-2"></span></p>
<h3 id="1411-overview"><a class="header" href="#1411-overview">14.1.1 Overview</a></h3>
<p><span id="index-histchars_002c-use-of-1"></span></p>
<p>A history expansion begins with the first character of the <code>histchars</code>
parameter, which is ‘<code>!</code>’ by default, and may occur anywhere on the
command line, including inside double quotes (but not inside single
quotes <code>’...’</code> or C-style quotes <code>$’...’</code> nor when escaped with a
backslash).</p>
<p>The first character is followed by an optional event designator (<a href="Expansion.html#Event-Designators">Event
Designators</a>) and then an optional word designator
(<a href="Expansion.html#Word-Designators">Word Designators</a>); if neither of these designators
is present, no history expansion occurs.</p>
<p>Input lines containing history expansions are echoed after being
expanded, but before any other expansions take place and before the
command is executed. It is this expanded form that is recorded as the
history event for later references.</p>
<p>History expansions do not nest.</p>
<p>By default, a history reference with no event designator refers to the
same event as any preceding history reference on that command line; if
it is the only history reference in a command, it refers to the previous
command. <span id="index-CSH_005fJUNKIE_005fHISTORY_002c-use-of"></span>
However, if the option <code>CSH_JUNKIE_HISTORY</code> is set, then every history
reference with no event specification <em>always</em> refers to the previous
command.</p>
<p>For example, ‘<code>!</code>’ is the event designator for the previous command, so
‘<code>!!:1</code>’ always refers to the first word of the previous command, and
‘<code>!!$</code>’ always refers to the last word of the previous command. With
<code>CSH_JUNKIE_HISTORY</code> set, then ‘<code>!:1</code>’ and ‘<code>!$</code>’ function in the same
manner as ‘<code>!!:1</code>’ and ‘<code>!!$</code>’, respectively. Conversely, if
<code>CSH_JUNKIE_HISTORY</code> is unset, then ‘<code>!:1</code>’ and ‘<code>!$</code>’ refer to the
first and last words, respectively, of the same event referenced by the
nearest other history reference preceding them on the current command
line, or to the previous command if there is no preceding reference.</p>
<p>The character sequence ‘<code>^``foo``^``bar</code>’ (where ‘<code>^</code>’ is actually the
second character of the <code>histchars</code> parameter) repeats the last command,
replacing the string <code>foo</code> with <code>bar</code>. More precisely, the sequence
‘<code>^``foo``^``bar``^</code>’ is synonymous with ‘<code>!!:s``^``foo``^``bar``^</code>’,
hence other modifiers (see <a href="Expansion.html#Modifiers">Modifiers</a>) may follow the final
‘<code>^</code>’. In particular, ‘<code>^``foo``^``bar``^:G</code>’ performs a global
substitution.</p>
<p>If the shell encounters the character sequence ‘<code>!&quot;</code>’ in the input, the
history mechanism is temporarily disabled until the current list (see
<a href="Shell-Grammar.html#Shell-Grammar">Shell Grammar</a>) is fully parsed. The
‘<code>!&quot;</code>’ is removed from the input, and any subsequent ‘<code>!</code>’ characters
have no special significance.</p>
<p><span id="index-fc_002c-use-of"></span></p>
<p>A less convenient but more comprehensible form of command history
support is provided by the <code>fc</code> builtin.</p>
<hr />
<p><span id="Event-Designators"></span>
<span id="Event-Designators-1"></span></p>
<h3 id="1412-event-designators"><a class="header" href="#1412-event-designators">14.1.2 Event Designators</a></h3>
<p><span id="index-history-event-designators"></span>
<span id="index-event-designators_002c-history"></span></p>
<p>An event designator is a reference to a command-line entry in the
history list. In the list below, remember that the initial <code>‘!’</code> in each
item may be changed to another character by setting the <code>histchars</code>
parameter.</p>
<ul>
<li>
<p><code>!</code><br />
Start a history expansion, except when followed by a blank, newline,
‘<code>=</code>’ or ‘<code>(</code>’. If followed immediately by a word designator (<a href="Expansion.html#Word-Designators">Word
Designators</a>), this forms a history reference
with no event designator (<a href="Expansion.html#Overview">Overview</a>).</p>
</li>
<li>
<p><code>!!</code><br />
Refer to the previous command. By itself, this expansion repeats the
previous command.</p>
</li>
<li>
<p><code>!``n</code><br />
Refer to command-line <code>n</code>.</p>
</li>
<li>
<p><code>!-``n</code><br />
Refer to the current command-line minus <code>n</code>.</p>
</li>
<li>
<p><code>!``str</code><br />
Refer to the most recent command starting with <code>str</code>.</p>
</li>
<li>
<p><code>!?``str</code>[<code>?</code>]<br />
Refer to the most recent command containing <code>str</code>. The trailing
‘<code>?</code>’ is necessary if this reference is to be followed by a
modifier or followed by any text that is not to be considered part
of <code>str</code>.</p>
</li>
<li>
<p><code>!#</code><br />
Refer to the current command line typed in so far. The line is
treated as if it were complete up to and including the word before
the one with the ‘<code>!#</code>’ reference.</p>
</li>
<li>
<p><code>!{</code>...<code>}</code><br />
Insulate a history reference from adjacent characters (if
necessary).</p>
</li>
</ul>
<hr />
<p><span id="Word-Designators"></span>
<span id="Word-Designators-1"></span></p>
<h3 id="1413-word-designators"><a class="header" href="#1413-word-designators">14.1.3 Word Designators</a></h3>
<p><span id="index-history-word-designators"></span>
<span id="index-word-designators_002c-history"></span></p>
<p>A word designator indicates which word or words of a given command line
are to be included in a history reference. A ‘<code>:</code>’ usually separates the
event specification from the word designator. It may be omitted only if
the word designator begins with a ‘<code>^</code>’, ‘<code>$</code>’, ‘<code>*</code>’, ‘<code>-</code>’ or ‘<code>%</code>’.
Word designators include:</p>
<ul>
<li>
<p><code>0</code><br />
The first input word (command).</p>
</li>
<li>
<p><code>n</code><br />
The <code>n</code>th argument.</p>
</li>
<li>
<p><code>^</code><br />
The first argument. That is, <code>1</code>.</p>
</li>
<li>
<p><code>$</code><br />
The last argument.</p>
</li>
<li>
<p><code>%</code><br />
The word matched by (the most recent) <code>?``str</code> search.</p>
</li>
<li>
<p><code>x``-``y</code><br />
A range of words; <code>x</code> defaults to <code>0</code>.</p>
</li>
<li>
<p><code>*</code><br />
All the arguments, or a null value if there are none.</p>
</li>
<li>
<p><code>x``*</code><br />
Abbreviates ‘<code>x``-$</code>’.</p>
</li>
<li>
<p><code>x``-</code><br />
Like ‘<code>x``*</code>’ but omitting word <code>$</code>.</p>
</li>
</ul>
<p>Note that a ‘<code>%</code>’ word designator works only when used in one of ‘<code>!%</code>’,
‘<code>!:%</code>’ or ‘<code>!?``str``?:%</code>’, and only when used after a <code>!?</code> expansion
(possibly in an earlier command). Anything else results in an error,
although the error may not be the most obvious one.</p>
<hr />
<p><span id="Modifiers"></span> <span id="Modifiers-1"></span></p>
<h3 id="1414-modifiers"><a class="header" href="#1414-modifiers">14.1.4 Modifiers</a></h3>
<p><span id="index-modifiers"></span>
<span id="index-colon-modifiers"></span>
<span id="index-history-modifiers"></span>
<span id="index-globbing-modifiers"></span>
<span id="index-parameter-modifiers"></span></p>
<p>After the optional word designator, you can add a sequence of one or
more of the following modifiers, each preceded by a ‘<code>:</code>’. These
modifiers also work on the result of <em>filename generation</em> and
<em>parameter expansion</em>, except where noted.</p>
<ul>
<li>
<p><code>a</code><br />
Turn a file name into an absolute path: prepends the current
directory, if necessary; remove ‘<code>.</code>’ path segments; and remove
‘<code>..</code>’ path segments and the segments that immediately precede
them.</p>
<p>This transformation is agnostic about what is in the filesystem,
i.e. is on the logical, not the physical directory. It takes place
in the same manner as when changing directories when neither of the
options <code>CHASE_DOTS</code> or <code>CHASE_LINKS</code> is set. For example,
‘<code>/before/here/../after</code>’ is always transformed to
‘<code>/before/after</code>’, regardless of whether ‘<code>/before/here</code>’ exists
or what kind of object (dir, file, symlink, etc.) it is.</p>
</li>
<li>
<p><code>A</code><br />
Turn a file name into an absolute path as the ‘<code>a</code>’ modifier does,
and <em>then</em> pass the result through the <code>realpath(3)</code> library
function to resolve symbolic links.</p>
<p>Note: on systems that do not have a <code>realpath(3)</code> library function,
symbolic links are not resolved, so on those systems ‘<code>a</code>’ and ‘<code>A</code>’
are equivalent.</p>
<p>Note: <code>foo:A</code> and <code>realpath(foo)</code> are different on some inputs. For
<code>realpath(foo)</code> semantics, see the ‘<code>P</code>‘ modifier.</p>
</li>
<li>
<p><code>c</code><br />
Resolve a command name into an absolute path by searching the
command path given by the <code>PATH</code> variable. This does not work for
commands containing directory parts. Note also that this does not
usually work as a glob qualifier unless a file of the same name is
found in the current directory.</p>
</li>
<li>
<p><code>e</code><br />
Remove all but the part of the filename extension following the
‘<code>.</code>’; see the definition of the filename extension in the
description of the <code>r</code> modifier below. Note that according to that
definition the result will be empty if the string ends with a ‘<code>.</code>’.</p>
</li>
<li>
<p><code>h</code> [ <code>digits</code> ]<br />
Remove a trailing pathname component, shortening the path by one
directory level: this is the ‘head’ of the pathname. This works like
‘<code>dirname</code>’. If the <code>h</code> is followed immediately (with no spaces or
other separator) by any number of decimal digits, and the value of
the resulting number is non-zero, that number of leading components
is preserved instead of the final component being removed. In an
absolute path the leading ‘<code>/</code>’ is the first component, so, for
example, if <code>var=/my/path/to/something</code>, then <code>${var:h3}</code>
substitutes <code>/my/path</code>. Consecutive ‘/’s are treated the same as a
single ‘/’. In parameter substitution, digits may only be used if
the expression is in braces, so for example the short form
substitution <code>$var:h2</code> is treated as <code>${var:h}2</code>, not as
<code>${var:h2}</code>. No restriction applies to the use of digits in history
substitution or globbing qualifiers. If more components are
requested than are present, the entire path is substituted (so this
does not trigger a ‘failed modifier’ error in history expansion).</p>
</li>
<li>
<p><code>l</code><br />
Convert the words to all lowercase.</p>
</li>
<li>
<p><code>p</code><br />
Print the new command but do not execute it. Only works with history
expansion.</p>
</li>
<li>
<p><code>P</code><br />
Turn a file name into an absolute path, like <code>realpath(3)</code>. The
resulting path will be absolute, have neither ‘<code>.</code>’ nor ‘<code>..</code>’
components, and refer to the same directory entry as the input
filename.</p>
<p>Unlike <code>realpath(3)</code>, non-existent trailing components are permitted
and preserved.</p>
</li>
<li>
<p><code>q</code><br />
Quote the substituted words, escaping further substitutions. Works
with history expansion and parameter expansion, though for
parameters it is only useful if the resulting text is to be
re-evaluated such as by <code>eval</code>.</p>
</li>
<li>
<p><code>Q</code><br />
Remove one level of quotes from the substituted words.</p>
</li>
<li>
<p><code>r</code><br />
Remove a filename extension leaving the root name. Strings with no
filename extension are not altered. A filename extension is a ‘<code>.</code>’
followed by any number of characters (including zero) that are
neither ‘<code>.</code>’ nor ‘<code>/</code>’ and that continue to the end of the string.
For example, the extension of ‘<code>foo.orig.c</code>’ is ‘<code>.c</code>’, and
‘<code>dir.c/foo</code>’ has no extension.</p>
</li>
<li>
<p><code>s/``l``/``r</code>[<code>/</code>]<br />
Substitute <code>r</code> for <code>l</code> as described below. The substitution is done
only for the first string that matches <code>l</code>. For arrays and for
filename generation, this applies to each word of the expanded text.
See below for further notes on substitutions.</p>
<p>The forms ‘<code>gs/``l``/``r</code>’ and ‘<code>s/``l``/``r``/:G</code>’ perform global
substitution, i.e. substitute every occurrence of <code>r</code> for <code>l</code>. Note
that the <code>g</code> or <code>:G</code> must appear in exactly the position shown.</p>
<p>See further notes on this form of substitution below.</p>
</li>
<li>
<p><code>&amp;</code><br />
Repeat the previous <code>s</code> substitution. Like <code>s</code>, may be preceded
immediately by a <code>g</code>. In parameter expansion the <code>&amp;</code> must appear
inside braces, and in filename generation it must be quoted with a
backslash.</p>
</li>
<li>
<p><code>t</code> [ <code>digits</code> ]<br />
Remove all leading pathname components, leaving the final component
(tail). This works like ‘<code>basename</code>’. Any trailing slashes are first
removed. Decimal digits are handled as described above for (h), but
in this case that number of trailing components is preserved instead
of the default 1; 0 is treated the same as 1.</p>
</li>
<li>
<p><code>u</code><br />
Convert the words to all uppercase.</p>
</li>
<li>
<p><code>x</code><br />
Like <code>q</code>, but break into words at whitespace. Does not work with
parameter expansion.</p>
</li>
</ul>
<p>The <code>s/``l``/``r``/</code> substitution works as follows. By default the
left-hand side of substitutions are not patterns, but character strings.
Any character can be used as the delimiter in place of ‘<code>/</code>’. A
backslash quotes the delimiter character. The character ‘<code>&amp;</code>’, in the
right-hand-side <code>r</code>, is replaced by the text from the left-hand-side
<code>l</code>. The ‘<code>&amp;</code>’ can be quoted with a backslash. A null <code>l</code> uses the
previous string either from the previous <code>l</code> or from the contextual scan
string <code>s</code> from ‘<code>!?``s</code>’. You can omit the rightmost delimiter if a
newline immediately follows <code>r</code>; the rightmost ‘<code>?</code>’ in a context scan
can similarly be omitted. Note the same record of the last <code>l</code> and <code>r</code>
is maintained across all forms of expansion.</p>
<p>Note that if a ‘<code>&amp;</code>’ is used within glob qualifiers an extra backslash
is needed as a <code>&amp;</code> is a special character in this case.</p>
<p>Also note that the order of expansions affects the interpretation of <code>l</code>
and <code>r</code>. When used in a history expansion, which occurs before any other
expansions, <code>l</code> and <code>r</code> are treated as literal strings (except as
explained for <code>HIST_SUBST_PATTERN</code> below). When used in parameter
expansion, the replacement of <code>r</code> into the parameter’s value is done
first, and then any additional process, parameter, command, arithmetic,
or brace references are applied, which may evaluate those substitutions
and expansions more than once if <code>l</code> appears more than once in the
starting value. When used in a glob qualifier, any substitutions or
expansions are performed once at the time the qualifier is parsed, even
before the ‘<code>:s</code>’ expression itself is divided into <code>l</code> and <code>r</code> sides.</p>
<p>If the option <code>HIST_SUBST_PATTERN</code> is set, <code>l</code> is treated as a pattern
of the usual form described in <a href="Expansion.html#Filename-Generation">Filename
Generation</a>. This can be used in all the places
where modifiers are available; note, however, that in globbing
qualifiers parameter substitution has already taken place, so parameters
in the replacement string should be quoted to ensure they are replaced
at the correct time. Note also that complicated patterns used in
globbing qualifiers may need the extended glob qualifier notation
<code>(#q:s/``...``/``...``/)</code> in order for the shell to recognize the
expression as a glob qualifier. Further, note that bad patterns in the
substitution are not subject to the <code>NO_BAD_PATTERN</code> option so will
cause an error.</p>
<p>When <code>HIST_SUBST_PATTERN</code> is set, <code>l</code> may start with a <code>#</code> to indicate
that the pattern must match at the start of the string to be
substituted, and a <code>%</code> may appear at the start or after an <code>#</code> to
indicate that the pattern must match at the end of the string to be
substituted. The <code>%</code> or <code>#</code> may be quoted with two backslashes.</p>
<p>For example, the following piece of filename generation code with the
<code>EXTENDED_GLOB</code> option:</p>
<div class="example">
<pre><code class="language-example">print -r -- *.c(#q:s/#%(#b)s(*).c/'S${match[1]}.C'/)
</code></pre>
</div>
<p>takes the expansion of <code>*.c</code> and applies the glob qualifiers in the
<code>(#q``...``)</code> expression, which consists of a substitution modifier
anchored to the start and end of each word (<code>#%</code>). This turns on
backreferences (<code>(#b)</code>), so that the parenthesised subexpression is
available in the replacement string as <code>${match[1]}</code>. The replacement
string is quoted so that the parameter is not substituted before the
start of filename generation.</p>
<p>The following <code>f</code>, <code>F</code>, <code>w</code> and <code>W</code> modifiers work only with parameter
expansion and filename generation. They are listed here to provide a
single point of reference for all modifiers.</p>
<ul>
<li>
<p><code>f</code><br />
Repeats the immediately (without a colon) following modifier until
the resulting word doesn’t change any more.</p>
</li>
<li>
<p><code>F:``expr``:</code><br />
Like <code>f</code>, but repeats only <code>n</code> times if the expression <code>expr</code>
evaluates to <code>n</code>. Any character can be used instead of the ‘<code>:</code>’; if
‘<code>(</code>’, ‘<code>[</code>’, or ‘<code>{</code>’ is used as the opening delimiter, the closing
delimiter should be ’<code>)</code>’, ‘<code>]</code>’, or ‘<code>}</code>’, respectively.</p>
</li>
<li>
<p><code>w</code><br />
Makes the immediately following modifier work on each word in the
string.</p>
</li>
<li>
<p><code>W:``sep``:</code><br />
Like <code>w</code> but words are considered to be the parts of the string that
are separated by <code>sep</code>. Any character can be used instead of the
‘<code>:</code>’; opening parentheses are handled specially, see above.</p>
</li>
</ul>
<hr />
<p><span id="Process-Substitution"></span>
<span id="Process-Substitution-1"></span></p>
<h2 id="142-process-substitution"><a class="header" href="#142-process-substitution">14.2 Process Substitution</a></h2>
<p><span id="index-process-substitution"></span>
<span id="index-substitution_002c-process"></span></p>
<p>Each part of a command argument that takes the form ‘<code>&lt;(``list``)</code>’,
‘<code>&gt;(``list``)</code>’ or ‘<code>=(``list``)</code>’ is subject to process substitution.
The expression may be preceded or followed by other strings except that,
to prevent clashes with commonly occurring strings and patterns, the
last form must occur at the start of a command argument, and the forms
are only expanded when first parsing command or assignment arguments.
Process substitutions may be used following redirection operators; in
this case, the substitution must appear with no trailing string.</p>
<p>Note that ‘<code>&lt;&lt;(``list``)</code>’ is not a special syntax; it is equivalent to
‘<code>&lt; &lt;(``list``)</code>’, redirecting standard input from the result of
process substitution. Hence all the following documentation applies. The
second form (with the space) is recommended for clarity.</p>
<p>In the case of the <code>&lt;</code> or <code>&gt;</code> forms, the shell runs the commands in
<code>list</code> as a subprocess of the job executing the shell command line. If
the system supports the <code>/dev/fd</code> mechanism, the command argument is the
name of the device file corresponding to a file descriptor; otherwise,
if the system supports named pipes (FIFOs), the command argument will be
a named pipe. If the form with <code>&gt;</code> is selected then writing on this
special file will provide input for <code>list</code>. If <code>&lt;</code> is used, then the
file passed as an argument will be connected to the output of the <code>list</code>
process. For example,</p>
<div class="example">
<pre><code class="language-example">paste &lt;(cut -f1 file1) &lt;(cut -f3 file2) |
tee &gt;(process1) &gt;(process2) &gt;/dev/null
</code></pre>
</div>
<p>cuts fields 1 and 3 from the files <code>file1</code> and <code>file2</code> respectively,
pastes the results together, and sends it to the processes <code>process1</code>
and <code>process2</code>.</p>
<p>If <code>=(``...``)</code> is used instead of <code>&lt;(``...``)</code>, then the file passed as
an argument will be the name of a temporary file containing the output
of the <code>list</code> process. This may be used instead of the <code>&lt;</code> form for a
program that expects to lseek (see man page lseek(2)) on the input file.</p>
<p>There is an optimisation for substitutions of the form <code>=(&lt;&lt;&lt;``arg``)</code>,
where <code>arg</code> is a single-word argument to the here-string redirection
<code>&lt;&lt;&lt;</code>. This form produces a file name containing the value of <code>arg</code>
after any substitutions have been performed. This is handled entirely
within the current shell. This is effectively the reverse of the special
form <code>$(&lt;``arg``)</code> which treats <code>arg</code> as a file name and replaces it
with the file’s contents.</p>
<p>The <code>=</code> form is useful as both the <code>/dev/fd</code> and the named pipe
implementation of <code>&lt;(``...``)</code> have drawbacks. In the former case, some
programmes may automatically close the file descriptor in question
before examining the file on the command line, particularly if this is
necessary for security reasons such as when the programme is running
setuid. In the second case, if the programme does not actually open the
file, the subshell attempting to read from or write to the pipe will (in
a typical implementation, different operating systems may have different
behaviour) block for ever and have to be killed explicitly. In both
cases, the shell actually supplies the information using a pipe, so that
programmes that expect to lseek (see man page lseek(2)) on the file will
not work.</p>
<p>Also note that the previous example can be more compactly and
efficiently written (provided the <code>MULTIOS</code> option is set) as:</p>
<div class="example">
<pre><code class="language-example">paste &lt;(cut -f1 file1) &lt;(cut -f3 file2) &gt; &gt;(process1) &gt; &gt;(process2)
</code></pre>
</div>
<p>The shell uses pipes instead of FIFOs to implement the latter two
process substitutions in the above example.</p>
<p>There is an additional problem with <code>&gt;(``process``)</code>; when this is
attached to an external command, the parent shell does not wait for
<code>process</code> to finish and hence an immediately following command cannot
rely on the results being complete. The problem and solution are the
same as described in the section <em>MULTIOS</em> in
<a href="Redirection.html#Redirection">Redirection</a>. Hence in a simplified
version of the example above:</p>
<div class="example">
<pre><code class="language-example">paste &lt;(cut -f1 file1) &lt;(cut -f3 file2) &gt; &gt;(process)
</code></pre>
</div>
<p>(note that no <code>MULTIOS</code> are involved), <code>process</code> will be run
asynchronously as far as the parent shell is concerned. The workaround
is:</p>
<div class="example">
<pre><code class="language-example">{ paste &lt;(cut -f1 file1) &lt;(cut -f3 file2) } &gt; &gt;(process)
</code></pre>
</div>
<p>The extra processes here are spawned from the parent shell which will
wait for their completion.</p>
<p>Another problem arises any time a job with a substitution that requires
a temporary file is disowned by the shell, including the case where
‘<code>&amp;!</code>’ or ‘<code>&amp;|</code>’ appears at the end of a command containing a
substitution. In that case the temporary file will not be cleaned up as
the shell no longer has any memory of the job. A workaround is to use a
subshell, for example,</p>
<div class="example">
<pre><code class="language-example">(mycmd =(myoutput)) &amp;!
</code></pre>
</div>
<p>as the forked subshell will wait for the command to finish then remove
the temporary file.</p>
<p>A general workaround to ensure a process substitution endures for an
appropriate length of time is to pass it as a parameter to an anonymous
shell function (a piece of shell code that is run immediately with
function scope). For example, this code:</p>
<div class="example">
<pre><code class="language-example">() {
print File $1:
cat $1
} =(print This be the verse)
</code></pre>
</div>
<p>outputs something resembling the following</p>
<div class="example">
<pre><code class="language-example">File /tmp/zsh6nU0kS:
This be the verse
</code></pre>
</div>
<p>The temporary file created by the process substitution will be deleted
when the function exits.</p>
<hr />
<p><span id="Parameter-Expansion"></span>
<span id="Parameter-Expansion-1"></span></p>
<h2 id="143-parameter-expansion"><a class="header" href="#143-parameter-expansion">14.3 Parameter Expansion</a></h2>
<p><span id="index-parameter-expansion"></span>
<span id="index-expansion_002c-parameter"></span></p>
<p>The character ‘<code>$</code>’ is used to introduce parameter expansions. See
<a href="Parameters.html#Parameters">Parameters</a> for a description of
parameters, including arrays, associative arrays, and subscript notation
to access individual array elements.</p>
<p>Note in particular the fact that words of unquoted parameters are not
automatically split on whitespace unless the option <code>SH_WORD_SPLIT</code> is
set; see references to this option below for more details. This is an
important difference from other shells. However, as in other shells,
null words are elided from unquoted parameters’ expansions.</p>
<p>With default options, after the assignments:</p>
<div class="example">
<pre><code class="language-example">array=(&quot;first word&quot; &quot;&quot; &quot;third word&quot;)
scalar=&quot;only word&quot;
</code></pre>
</div>
<p>then <code>$array</code> substitutes two words, ‘<code>first word</code>’ and ‘<code>third word</code>’,
and <code>$scalar</code> substitutes a single word ‘<code>only word</code>’. Note that second
element of <code>array</code> was elided. Scalar parameters can be elided too if
their value is null (empty). To avoid elision, use quoting as follows:
<code>&quot;$scalar&quot;</code> for scalars and <code>&quot;${array[@]}&quot;</code> or <code>&quot;${(@)array}&quot;</code> for
arrays. (The last two forms are equivalent.)</p>
<p>Parameter expansions can involve <em>flags</em>, as in ‘<code>${(@kv)aliases}</code>’, and
other operators, such as ‘<code>${PREFIX:-&quot;/usr/local&quot;}</code>’. Parameter
expansions can also be nested. These topics will be introduced below.
The full rules are complicated and are noted at the end.</p>
<p>In the expansions discussed below that require a pattern, the form of
the pattern is the same as that used for filename generation; see
<a href="Expansion.html#Filename-Generation">Filename Generation</a>. Note that these patterns,
along with the replacement text of any substitutions, are themselves
subject to parameter expansion, command substitution, and arithmetic
expansion. In addition to the following operations, the colon modifiers
described in <a href="Expansion.html#Modifiers">Modifiers</a> in <a href="Expansion.html#History-Expansion">History
Expansion</a> can be applied: for example,
<code>${i:s/foo/bar/}</code> performs string substitution on the expansion of
parameter <code>$i</code>.</p>
<p>In the following descriptions, ‘<code>word</code>’ refers to a single word
substituted on the command line, not necessarily a space delimited word.</p>
<ul>
<li>
<p><code>${``name``}</code><br />
The value, if any, of the parameter <code>name</code> is substituted. The
braces are required if the expansion is to be followed by a letter,
digit, or underscore that is not to be interpreted as part of
<code>name</code>. In addition, more complicated forms of substitution usually
require the braces to be present; exceptions, which only apply if
the option <code>KSH_ARRAYS</code> is not set, are a single subscript or any
colon modifiers appearing after the name, or any of the characters
‘<code>^</code>’, ‘<code>=</code>’, ‘<code>~</code>’, ‘<code>#</code>’ or ‘<code>+</code>’ appearing before the name, all
of which work with or without braces.</p>
<p>If <code>name</code> is an array parameter, and the <code>KSH_ARRAYS</code> option is not
set, then the value of each element of <code>name</code> is substituted, one
element per word. Otherwise, the expansion results in one word only;
with <code>KSH_ARRAYS</code>, this is the first element of an array. No field
splitting is done on the result unless the <code>SH_WORD_SPLIT</code> option is
set. See also the flags <code>=</code> and <code>s:``string``:</code>.</p>
</li>
<li>
<p><code>${+``name``}</code><br />
If <code>name</code> is the name of a set parameter ‘<code>1</code>’ is substituted,
otherwise ‘<code>0</code>’ is substituted.</p>
</li>
<li>
<p><code>${``name``-``word``}</code><br />
<code>${``name``:-``word``}</code><br />
If <code>name</code> is set, or in the second form is non-null, then substitute
its value; otherwise substitute <code>word</code>. In the second form <code>name</code>
may be omitted, in which case <code>word</code> is always substituted.</p>
</li>
<li>
<p><code>${``name``+``word``}</code><br />
<code>${``name``:+``word``}</code><br />
If <code>name</code> is set, or in the second form is non-null, then substitute
<code>word</code>; otherwise substitute nothing.</p>
</li>
<li>
<p><code>${``name``=``word``}</code><br />
<code>${``name``:=``word``}</code><br />
<code>${``name``::=``word``}</code><br />
In the first form, if <code>name</code> is unset then set it to <code>word</code>; in the
second form, if <code>name</code> is unset or null then set it to <code>word</code>; and
in the third form, unconditionally set <code>name</code> to <code>word</code>. In all
forms, the value of the parameter is then substituted.</p>
</li>
<li>
<p><code>${``name``?``word``}</code><br />
<code>${``name``:?``word``}</code><br />
In the first form, if <code>name</code> is set, or in the second form if <code>name</code>
is both set and non-null, then substitute its value; otherwise,
print <code>word</code> and exit from the shell. Interactive shells instead
return to the prompt. If <code>word</code> is omitted, then a standard message
is printed.</p>
</li>
</ul>
<p>In any of the above expressions that test a variable and substitute an
alternate <code>word</code>, note that you can use standard shell quoting in the
<code>word</code> value to selectively override the splitting done by the
<code>SH_WORD_SPLIT</code> option and the <code>=</code> flag, but not splitting by the
<code>s:``string``:</code> flag.</p>
<p>In the following expressions, when <code>name</code> is an array and the
substitution is not quoted, or if the ‘<code>(@)</code>’ flag or the <code>name``[@]</code>
syntax is used, matching and replacement is performed on each array
element separately.</p>
<ul>
<li>
<p><code>${``name``#``pattern``}</code><br />
<code>${``name``##``pattern``}</code><br />
If the <code>pattern</code> matches the beginning of the value of <code>name</code>, then
substitute the value of <code>name</code> with the matched portion deleted;
otherwise, just substitute the value of <code>name</code>. In the first form,
the smallest matching pattern is preferred; in the second form, the
largest matching pattern is preferred.</p>
</li>
<li>
<p><code>${``name``%``pattern``}</code><br />
<code>${``name``%%``pattern``}</code><br />
If the <code>pattern</code> matches the end of the value of <code>name</code>, then
substitute the value of <code>name</code> with the matched portion deleted;
otherwise, just substitute the value of <code>name</code>. In the first form,
the smallest matching pattern is preferred; in the second form, the
largest matching pattern is preferred.</p>
</li>
<li>
<p><code>${``name``:#``pattern``}</code><br />
If the <code>pattern</code> matches the value of <code>name</code>, then substitute the
empty string; otherwise, just substitute the value of <code>name</code>. If
<code>name</code> is an array the matching array elements are removed (use the
‘<code>(M)</code>’ flag to remove the non-matched elements).</p>
</li>
<li>
<p><code>${``name``:|``arrayname``}</code><br />
If <code>arrayname</code> is the name (N.B., not contents) of an array
variable, then any elements contained in <code>arrayname</code> are removed
from the substitution of <code>name</code>. If the substitution is scalar,
either because <code>name</code> is a scalar variable or the expression is
quoted, the elements of <code>arrayname</code> are instead tested against the
entire expression.</p>
</li>
<li>
<p><code>${``name``:*``arrayname``}</code><br />
Similar to the preceding substitution, but in the opposite sense, so
that entries present in both the original substitution and as
elements of <code>arrayname</code> are retained and others removed.</p>
</li>
<li>
<p><code>${``name``:^``arrayname``}</code><br />
<code>${``name``:^^``arrayname``}</code><br />
Zips two arrays, such that the output array is twice as long as the
shortest (longest for ‘<code>:^^</code>’) of <code>name</code> and <code>arrayname</code>, with the
elements alternatingly being picked from them. For ‘<code>:^</code>’, if one of
the input arrays is longer, the output will stop when the end of the
shorter array is reached. Thus,</p>
<div class="example">
<pre><code class="language-example">a=(1 2 3 4); b=(a b); print ${a:^b}
</code></pre>
</div>
<p>will output ‘<code>1 a 2 b</code>’. For ‘<code>:^^</code>’, then the input is repeated
until all of the longer array has been used up and the above will
output ‘<code>1 a 2 b 3 a 4 b</code>’.</p>
<p>Either or both inputs may be a scalar, they will be treated as an
array of length 1 with the scalar as the only element. If either
array is empty, the other array is output with no extra elements
inserted.</p>
<p>Currently the following code will output ‘<code>a b</code>’ and ‘<code>1</code>’ as two
separate elements, which can be unexpected. The second print
provides a workaround which should continue to work if this is
changed.</p>
<div class="example">
<pre><code class="language-example">a=(a b); b=(1 2); print -l &quot;${a:^b}&quot;; print -l &quot;${${a:^b}}&quot;
</code></pre>
</div>
</li>
<li>
<p><code>${``name``:``offset``}</code><br />
<code>${``name``:``offset``:``length``}</code><br />
This syntax gives effects similar to parameter subscripting in the
form <code>$``name``[``start``,``end``]</code>, but is compatible with other
shells; note that both <code>offset</code> and <code>length</code> are interpreted
differently from the components of a subscript.</p>
<p>If <code>offset</code> is non-negative, then if the variable <code>name</code> is a scalar
substitute the contents starting <code>offset</code> characters from the first
character of the string, and if <code>name</code> is an array substitute
elements starting <code>offset</code> elements from the first element. If
<code>length</code> is given, substitute that many characters or elements,
otherwise the entire rest of the scalar or array.</p>
<p>A positive <code>offset</code> is always treated as the offset of a character
or element in <code>name</code> from the first character or element of the
array (this is different from native zsh subscript notation). Hence
0 refers to the first character or element regardless of the setting
of the option <code>KSH_ARRAYS</code>.</p>
<p>A negative offset counts backwards from the end of the scalar or
array, so that -1 corresponds to the last character or element, and
so on.</p>
<p>When positive, <code>length</code> counts from the <code>offset</code> position toward the
end of the scalar or array. When negative, <code>length</code> counts back from
the end. If this results in a position smaller than <code>offset</code>, a
diagnostic is printed and nothing is substituted.</p>
<p>The option <code>MULTIBYTE</code> is obeyed, i.e. the offset and length count
multibyte characters where appropriate.</p>
<p><code>offset</code> and <code>length</code> undergo the same set of shell substitutions as
for scalar assignment; in addition, they are then subject to
arithmetic evaluation. Hence, for example</p>
<div class="example">
<pre><code class="language-example">print ${foo:3}
print ${foo: 1 + 2}
print ${foo:$(( 1 + 2))}
print ${foo:$(echo 1 + 2)}
</code></pre>
</div>
<p>all have the same effect, extracting the string starting at the
fourth character of <code>$foo</code> if the substitution would otherwise
return a scalar, or the array starting at the fourth element if
<code>$foo</code> would return an array. Note that with the option <code>KSH_ARRAYS</code>
<code>$foo</code> always returns a scalar (regardless of the use of the offset
syntax) and a form such as <code>${foo[*]:3}</code> is required to extract
elements of an array named <code>foo</code>.</p>
<p>If <code>offset</code> is negative, the <code>-</code> may not appear immediately after
the <code>:</code> as this indicates the <code>${``name``:-``word``}</code> form of
substitution. Instead, a space may be inserted before the <code>-</code>.
Furthermore, neither <code>offset</code> nor <code>length</code> may begin with an
alphabetic character or <code>&amp;</code> as these are used to indicate
history-style modifiers. To substitute a value from a variable, the
recommended approach is to precede it with a <code>$</code> as this signifies
the intention (parameter substitution can easily be rendered
unreadable); however, as arithmetic substitution is performed, the
expression <code>${var: offs}</code> does work, retrieving the offset from
<code>$offs</code>.</p>
<p>For further compatibility with other shells there is a special case
for array offset 0. This usually accesses the first element of the
array. However, if the substitution refers to the positional
parameter array, e.g. <code>$@</code> or <code>$*</code>, then offset 0 instead refers to
<code>$0</code>, offset 1 refers to <code>$1</code>, and so on. In other words, the
positional parameter array is effectively extended by prepending
<code>$0</code>. Hence <code>${*:0:1}</code> substitutes <code>$0</code> and <code>${*:1:1}</code> substitutes
<code>$1</code>.</p>
</li>
<li>
<p><code>${``name``/``pattern``/``repl``}</code><br />
<code>${``name``//``pattern``/``repl``}</code><br />
<code>${``name``:/``pattern``/``repl``}</code><br />
Replace the longest possible match of <code>pattern</code> in the expansion of
parameter <code>name</code> by string <code>repl</code>. The first form replaces just the
first occurrence, the second form all occurrences, and the third
form replaces only if <code>pattern</code> matches the entire string. Both
<code>pattern</code> and <code>repl</code> are subject to double-quoted substitution, so
that expressions like <code>${name/$opat/$npat}</code> will work, but obey the
usual rule that pattern characters in <code>$opat</code> are not treated
specially unless either the option <code>GLOB_SUBST</code> is set, or <code>$opat</code>
is instead substituted as <code>${~opat}</code>.</p>
<p>The <code>pattern</code> may begin with a ‘<code>#</code>’, in which case the <code>pattern</code>
must match at the start of the string, or ‘<code>%</code>’, in which case it
must match at the end of the string, or ‘<code>#%</code>’ in which case the
<code>pattern</code> must match the entire string. The <code>repl</code> may be an empty
string, in which case the final ‘<code>/</code>’ may also be omitted. To quote
the final ‘<code>/</code>’ in other cases it should be preceded by a single
backslash; this is not necessary if the ‘<code>/</code>’ occurs inside a
substituted parameter. Note also that the ‘<code>#</code>’, ‘<code>%</code>’ and ‘<code>#%</code> are
not active if they occur inside a substituted parameter, even at the
start.</p>
<p>If, after quoting rules apply, <code>${``name``}</code> expands to an array,
the replacements act on each element individually. Note also the
effect of the <code>I</code> and <code>S</code> parameter expansion flags below; however,
the flags <code>M</code>, <code>R</code>, <code>B</code>, <code>E</code> and <code>N</code> are not useful.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">foo=&quot;twinkle twinkle little star&quot; sub=&quot;t*e&quot; rep=&quot;spy&quot;
print ${foo//${~sub}/$rep}
print ${(S)foo//${~sub}/$rep}
</code></pre>
</div>
<p>Here, the ‘<code>~</code>’ ensures that the text of <code>$sub</code> is treated as a
pattern rather than a plain string. In the first case, the longest
match for <code>t*e</code> is substituted and the result is ‘<code>spy star</code>’, while
in the second case, the shortest matches are taken and the result is
‘<code>spy spy lispy star</code>’.</p>
</li>
<li>
<p><code>${#``spec``}</code><br />
If <code>spec</code> is one of the above substitutions, substitute the length
in characters of the result instead of the result itself. If <code>spec</code>
is an array expression, substitute the number of elements of the
result. This has the side-effect that joining is skipped even in
quoted forms, which may affect other sub-expressions in <code>spec</code>. Note
that ‘<code>^</code>’, ‘<code>=</code>’, and ‘<code>~</code>’, below, must appear to the left of
‘<code>#</code>’ when these forms are combined.</p>
<p>If the option <code>POSIX_IDENTIFIERS</code> is not set, and <code>spec</code> is a simple
name, then the braces are optional; this is true even for special
parameters so e.g. <code>$#-</code> and <code>$#*</code> take the length of the string
<code>$-</code> and the array <code>$*</code> respectively. If <code>POSIX_IDENTIFIERS</code> is set,
then braces are required for the <code>#</code> to be treated in this fashion.</p>
</li>
<li>
<p><code>${^``spec``}</code><br />
<span id="index-RC_005fEXPAND_005fPARAM_002c-toggle"></span>
<span id="index-array-expansion-style_002c-rc"></span>
<span id="index-rc_002c-array-expansion-style"></span></p>
<p>Turn on the <code>RC_EXPAND_PARAM</code> option for the evaluation of <code>spec</code>;
if the ‘<code>^</code>’ is doubled, turn it off. When this option is set, array
expansions of the form <code>foo``${``xx``}``bar</code>, where the parameter
<code>xx</code> is set to <code>(``a b c``)</code>, are substituted with ‘<code>fooabar foobbar foocbar</code>’ instead of the default ‘<code>fooa b cbar</code>’. Note that an empty
array will therefore cause all arguments to be removed.</p>
<p>Internally, each such expansion is converted into the equivalent
list for brace expansion. E.g., <code>${^var}</code> becomes
<code>{$var[1],$var[2],</code>...<code>}</code>, and is processed as described in <a href="Expansion.html#Brace-Expansion">Brace
Expansion</a> below: note, however, the expansion
happens immediately, with any explicit brace expansion happening
later. If word splitting is also in effect the <code>$var[``N``]</code> may
themselves be split into different list elements.</p>
</li>
<li>
<p><code>${=``spec``}</code><br />
<span id="index-SH_005fWORD_005fSPLIT_002c-toggle"></span>
<span id="index-field-splitting_002c-sh-style_002c-parameter"></span>
<span id="index-sh_002c-field-splitting-style_002c-parameter"></span></p>
<p>Perform word splitting using the rules for <code>SH_WORD_SPLIT</code> during
the evaluation of <code>spec</code>, but regardless of whether the parameter
appears in double quotes; if the ‘<code>=</code>’ is doubled, turn it off.
<span id="index-IFS_002c-use-of"></span> This forces parameter
expansions to be split into separate words before substitution,
using <code>IFS</code> as a delimiter. This is done by default in most other
shells.</p>
<p>Note that splitting is applied to <code>word</code> in the assignment forms of
<code>spec</code> <em>before</em> the assignment to <code>name</code> is performed. This affects
the result of array assignments with the <code>A</code> flag.</p>
</li>
<li>
<p><code>${~``spec``}</code><br />
<span id="index-GLOB_005fSUBST_002c-toggle"></span></p>
<p>Turn on the <code>GLOB_SUBST</code> option for the evaluation of <code>spec</code>; if the
‘<code>~</code>’ is doubled, turn it off. When this option is set, the string
resulting from the expansion will be interpreted as a pattern
anywhere that is possible, such as in filename expansion and
filename generation and pattern-matching contexts like the right
hand side of the ‘<code>=</code>’ and ‘<code>!=</code>’ operators in conditions.</p>
<p>In nested substitutions, note that the effect of the <code>~</code> applies to
the result of the current level of substitution. A surrounding
pattern operation on the result may cancel it. Hence, for example,
if the parameter <code>foo</code> is set to <code>*</code>, <code>${~foo//\*/*.c}</code> is
substituted by the pattern <code>*.c</code>, which may be expanded by filename
generation, but <code>${${~foo}//\*/*.c}</code> substitutes to the string
<code>*.c</code>, which will not be further expanded.</p>
</li>
</ul>
<p>If a <code>${</code>...<code>}</code> type parameter expression or a <code>$(</code>...<code>)</code> type command
substitution is used in place of <code>name</code> above, it is expanded first and
the result is used as if it were the value of <code>name</code>. Thus it is
possible to perform nested operations: <code>${${foo#head}%tail}</code> substitutes
the value of <code>$foo</code> with both ‘<code>head</code>’ and ‘<code>tail</code>’ deleted. The form
with <code>$(</code>...<code>)</code> is often useful in combination with the flags described
next; see the examples below. Each <code>name</code> or nested <code>${</code>...<code>}</code> in a
parameter expansion may also be followed by a subscript expression as
described in <a href="Parameters.html#Array-Parameters">Array Parameters</a>.</p>
<p>Note that double quotes may appear around nested expressions, in which
case only the part inside is treated as quoted; for example,
<code>${(f)&quot;$(foo)&quot;}</code> quotes the result of <code>$(foo)</code>, but the flag ‘<code>(f)</code>’
(see below) is applied using the rules for unquoted expansions. Note
further that quotes are themselves nested in this context; for example,
in <code>&quot;${(@f)&quot;$(foo)&quot;}&quot;</code>, there are two sets of quotes, one surrounding
the whole expression, the other (redundant) surrounding the <code>$(foo)</code> as
before.</p>
<hr />
<p><span id="Parameter-Expansion-Flags"></span></p>
<h3 id="1431-parameter-expansion-flags"><a class="header" href="#1431-parameter-expansion-flags">14.3.1 Parameter Expansion Flags</a></h3>
<p><span id="index-parameter-expansion-flags"></span>
<span id="index-flags_002c-parameter-expansion"></span>
<span id="index-substitution_002c-parameter_002c-flags"></span></p>
<p>If the opening brace is directly followed by an opening parenthesis, the
string up to the matching closing parenthesis will be taken as a list of
flags. In cases where repeating a flag is meaningful, the repetitions
need not be consecutive; for example, ‘(<code>q%q%q</code>)’ means the same thing
as the more readable ‘(<code>%%qqq</code>)’. The following flags are supported:</p>
<ul>
<li>
<p><code>#</code><br />
Evaluate the resulting words as numeric expressions and output the
characters corresponding to the resulting integer. Note that this
form is entirely distinct from use of the <code>#</code> without parentheses.</p>
<p>If the <code>MULTIBYTE</code> option is set and the number is greater than 127
(i.e. not an ASCII character) it is treated as a Unicode character.</p>
</li>
<li>
<p><code>%</code><br />
Expand all <code>%</code> escapes in the resulting words in the same way as in
prompts (see <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>). If this flag is
given twice, full prompt expansion is done on the resulting words,
depending on the setting of the <code>PROMPT_PERCENT</code>, <code>PROMPT_SUBST</code> and
<code>PROMPT_BANG</code> options.</p>
</li>
<li>
<p><code>@</code><br />
In double quotes, array elements are put into separate words. E.g.,
‘<code>&quot;${(@)foo}&quot;</code>’ is equivalent to ‘<code>&quot;${foo[@]}&quot;</code>’ and
‘<code>&quot;${(@)foo[1,2]}&quot;</code>’ is the same as ‘<code>&quot;$foo[1]&quot; &quot;$foo[2]&quot;</code>’. This
is distinct from <em>field splitting</em> by the <code>f</code>, <code>s</code> or <code>z</code> flags,
which still applies within each array element.</p>
</li>
<li>
<p><code>A</code><br />
Convert the substitution into an array expression, even if it
otherwise would be scalar. This has lower precedence than
subscripting, so one level of nested expansion is required in order
that subscripts apply to array elements. Thus
<code>${${(A``)``name``}[1]}</code> yields the full value of <code>name</code> when <code>name</code>
is scalar.</p>
<p>This assigns an array parameter with ‘<code>${</code>...<code>=</code>...<code>}</code>’,
‘<code>${</code>...<code>:=</code>...<code>}</code>’ or ‘<code>${</code>...<code>::=</code>...<code>}</code>’. If this flag is
repeated (as in ‘<code>AA</code>’), assigns an associative array parameter.
Assignment is made before sorting or padding; if field splitting is
active, the <code>word</code> part is split before assignment. The <code>name</code> part
may be a subscripted range for ordinary arrays; when assigning an
associative array, the <code>word</code> part <em>must</em> be converted to an array,
for example by using ‘<code>${(AA)=``name``=</code>...<code>}</code>’ to activate field
splitting.</p>
<p>Surrounding context such as additional nesting or use of the value
in a scalar assignment may cause the array to be joined back into a
single string again.</p>
</li>
<li>
<p><code>a</code><br />
Sort in array index order; when combined with ‘<code>O</code>’ sort in reverse
array index order. Note that ‘<code>a</code>’ is therefore equivalent to the
default but ‘<code>Oa</code>’ is useful for obtaining an array’s elements in
reverse order.</p>
</li>
<li>
<p><code>b</code><br />
Quote with backslashes only characters that are special to pattern
matching. This is useful when the contents of the variable are to be
tested using <code>GLOB_SUBST</code>, including the <code>${~``...``}</code> switch.</p>
<p>Quoting using one of the <code>q</code> family of flags does not work for this
purpose since quotes are not stripped from non-pattern characters by
<code>GLOB_SUBST</code>. In other words,</p>
<div class="example">
<pre><code class="language-example">pattern=${(q)str}
[[ $str = ${~pattern} ]]
</code></pre>
</div>
<p>works if <code>$str</code> is ‘<code>a*b</code>’ but not if it is ‘<code>a b</code>’, whereas</p>
<div class="example">
<pre><code class="language-example">pattern=${(b)str}
[[ $str = ${~pattern} ]]
</code></pre>
</div>
<p>is always true for any possible value of <code>$str</code>.</p>
</li>
<li>
<p><code>c</code><br />
With <code>${#``name``}</code>, count the total number of characters in an
array, as if the elements were concatenated with spaces between
them. This is not a true join of the array, so other expressions
used with this flag may have an effect on the elements of the array
before it is counted.</p>
</li>
<li>
<p><code>C</code><br />
Capitalize the resulting words. ‘Words’ in this case refers to
sequences of alphanumeric characters separated by non-alphanumerics,
<em>not</em> to words that result from field splitting.</p>
</li>
<li>
<p><code>D</code><br />
Assume the string or array elements contain directories and attempt
to substitute the leading part of these by names. The remainder of
the path (the whole of it if the leading part was not substituted)
is then quoted so that the whole string can be used as a shell
argument. This is the reverse of ‘<code>~</code>’ substitution: see <a href="Expansion.html#Filename-Expansion">Filename
Expansion</a>.</p>
</li>
<li>
<p><code>e</code><br />
Perform single word shell expansions, namely <em>parameter expansion</em>,
<em>command substitution</em> and <em>arithmetic expansion</em>, on the result.
Such expansions can be nested but too deep recursion may have</p>
</li>
<li>
<p><code>f</code><br />
Split the result of the expansion at newlines. This is a shorthand
for ‘<code>ps:\n:</code>’.</p>
</li>
<li>
<p><code>F</code><br />
Join the words of arrays together using newline as a separator. This
is a shorthand for ‘<code>pj:\n:</code>’.</p>
</li>
<li>
<p><code>g:``opts``:</code><br />
Process escape sequences like the echo builtin when no options are
given (<code>g::</code>). With the <code>o</code> option, octal escapes don’t take a
leading zero. With the <code>c</code> option, sequences like ‘<code>^X</code>’ are also
processed. With the <code>e</code> option, processes ‘<code>\M-t</code>’ and similar
sequences like the print builtin. With both of the <code>o</code> and <code>e</code>
options, behaves like the print builtin except that in none of these
modes is ‘<code>\c</code>’ interpreted.</p>
</li>
<li>
<p><code>i</code><br />
Sort case-insensitively. May be combined with ‘<code>n</code>’ or ‘<code>O</code>’.</p>
</li>
<li>
<p><code>k</code><br />
If <code>name</code> refers to an associative array, substitute the <em>keys</em>
(element names) rather than the values of the elements. Used with
subscripts (including ordinary arrays), force indices or keys to be
substituted even if the subscript form refers to values. However,
this flag may not be combined with subscript ranges. With the
<code>KSH_ARRAYS</code> option a subscript ‘<code>[*]</code>’ or ‘<code>[@]</code>’ is needed to
operate on the whole array, as usual.</p>
</li>
<li>
<p><code>L</code><br />
Convert all letters in the result to lower case.</p>
</li>
<li>
<p><code>n</code><br />
Sort decimal integers numerically; if the first differing characters
of two test strings are not digits, sorting is lexical. Integers
with more initial zeroes are sorted before those with fewer or none.
Hence the array ‘<code>foo1 foo02 foo2 foo3 foo20 foo23</code>’ is sorted into
the order shown. May be combined with ‘<code>i</code>’ or ‘<code>O</code>’.</p>
</li>
<li>
<p><code>o</code><br />
Sort the resulting words in ascending order; if this appears on its
own the sorting is lexical and case-sensitive (unless the locale
renders it case-insensitive). Sorting in ascending order is the
default for other forms of sorting, so this is ignored if combined
with ‘<code>a</code>’, ‘<code>i</code>’ or ‘<code>n</code>’.</p>
</li>
<li>
<p><code>O</code><br />
Sort the resulting words in descending order; ‘<code>O</code>’ without ‘<code>a</code>’,
‘<code>i</code>’ or ‘<code>n</code>’ sorts in reverse lexical order. May be combined
with ‘<code>a</code>’, ‘<code>i</code>’ or ‘<code>n</code>’ to reverse the order of sorting.</p>
</li>
<li>
<p><code>P</code><br />
This forces the value of the parameter <code>name</code> to be interpreted as a
further parameter name, whose value will be used where appropriate.
Note that flags set with one of the <code>typeset</code> family of commands (in
particular case transformations) are not applied to the value of
<code>name</code> used in this fashion.</p>
<p>If used with a nested parameter or command substitution, the result
of that will be taken as a parameter name in the same way. For
example, if you have ‘<code>foo=bar</code>’ and ‘<code>bar=baz</code>’, the strings
<code>${(P)foo}</code>, <code>${(P)${foo}}</code>, and <code>${(P)$(echo bar)}</code> will be
expanded to ‘<code>baz</code>’.</p>
<p>Likewise, if the reference is itself nested, the expression with the
flag is treated as if it were directly replaced by the parameter
name. It is an error if this nested substitution produces an array
with more than one word. For example, if ‘<code>name=assoc</code>’ where the
parameter <code>assoc</code> is an associative array, then
‘<code>${${(P)name}[elt]}</code>’ refers to the element of the associative
subscripted ‘<code>elt</code>’.</p>
</li>
<li>
<p><code>q</code><br />
Quote characters that are special to the shell in the resulting
words with <code>$’\``NNN``’</code> form, with separate quotes for each octet.</p>
<p>If this flag is given twice, the resulting words are quoted in
single quotes and if it is given three times, the words are quoted
in double characters is attempted. If the flag is given four times,
the words are quoted in single quotes preceded by a <code>$</code>. Note that
in all three of these forms quoting is done unconditionally, even if
this does not change the way the resulting string would be
interpreted by the shell.</p>
<p>If a <code>q-</code> is given (only a single <code>q</code> may appear), a minimal form of
single quoting is used that only quotes the string if needed to
protect special characters. Typically this form gives the most
readable output.</p>
<p>If a <code>q+</code> is given, an extended form of minimal quoting is used that
This quoting is similar to that used by the output of values by the
<code>typeset</code> family of commands.</p>
</li>
<li>
<p><code>Q</code><br />
Remove one level of quotes from the resulting words.</p>
</li>
<li>
<p><code>t</code><br />
Use a string describing the type of the parameter where the value of
the parameter would usually appear. This string consists of keywords
separated by hyphens (‘<code>-</code>’). The first keyword in the string
describes the main type, it can be one of ‘<code>scalar</code>’, ‘<code>array</code>’,
‘<code>integer</code>’, ‘<code>float</code>’ or ‘<code>association</code>’. The other keywords
describe the type in more detail:</p>
<ul>
<li>
<p><code>local</code><br />
for local parameters</p>
</li>
<li>
<p><code>left</code><br />
for left justified parameters</p>
</li>
<li>
<p><code>right_blanks</code><br />
for right justified parameters with leading blanks</p>
</li>
<li>
<p><code>right_zeros</code><br />
for right justified parameters with leading zeros</p>
</li>
<li>
<p><code>lower</code><br />
for parameters whose value is converted to all lower case when
it is expanded</p>
</li>
<li>
<p><code>upper</code><br />
for parameters whose value is converted to all upper case when
it is expanded</p>
</li>
<li>
<p><code>readonly</code><br />
for readonly parameters</p>
</li>
<li>
<p><code>tag</code><br />
for tagged parameters</p>
</li>
<li>
<p><code>export</code><br />
for exported parameters</p>
</li>
<li>
<p><code>unique</code><br />
for arrays which keep only the first occurrence of duplicated
values</p>
</li>
<li>
<p><code>hide</code><br />
for parameters with the ‘hide’ flag</p>
</li>
<li>
<p><code>hideval</code><br />
for parameters with the ‘hideval’ flag</p>
</li>
<li>
<p><code>special</code><br />
for special parameters defined by the shell</p>
</li>
</ul>
</li>
<li>
<p><code>u</code><br />
Expand only the first occurrence of each unique word.</p>
</li>
<li>
<p><code>U</code><br />
Convert all letters in the result to upper case.</p>
</li>
<li>
<p><code>v</code><br />
Used with <code>k</code>, substitute (as two consecutive words) both the key
and the value of each associative array element. Used with
subscripts, force values to be substituted even if the subscript
form refers to indices or keys.</p>
</li>
<li>
<p><code>V</code><br />
Make any special characters in the resulting words visible.</p>
</li>
<li>
<p><code>w</code><br />
With <code>${#``name``}</code>, count words in arrays or strings; the <code>s</code> flag
may be used to set a word delimiter.</p>
</li>
<li>
<p><code>W</code><br />
Similar to <code>w</code> with the difference that empty words between repeated
delimiters are also counted.</p>
</li>
<li>
<p><code>X</code><br />
With this flag, parsing errors occurring with the <code>Q</code>, <code>e</code> and <code>#</code>
flags or the pattern matching forms such as
‘<code>${``name``#``pattern``}</code>’ are reported. Without the flag, errors
are silently ignored.</p>
</li>
<li>
<p><code>z</code><br />
Split the result of the expansion into words using shell parsing to
find the words, i.e. taking into account any quoting in the value.
Comments are not treated specially but as ordinary strings, similar
to interactive shells with the <code>INTERACTIVE_COMMENTS</code> option unset
(however, see the <code>Z</code> flag below for related options)</p>
<p>Note that this is done very late, even later than the ‘<code>(s)</code>’ flag.
So to access single words in the result use nested expansions as in
‘<code>${${(z)foo}[2]}</code>’. Likewise, to remove the quotes in the
resulting words use ‘<code>${(Q)${(z)foo}}</code>’.</p>
</li>
<li>
<p><code>0</code><br />
Split the result of the expansion on null bytes. This is a shorthand
for ‘<code>ps:\0:</code>’.</p>
</li>
</ul>
<p>The following flags (except <code>p</code>) are followed by one or more arguments
as shown. Any character, or the matching pairs ‘<code>(</code>...<code>)</code>’, ‘<code>{</code>...<code>}</code>’,
‘<code>[</code>...<code>]</code>’, or ‘<code>&lt;</code>...<code>&gt;</code>’, may be used in place of a colon as
delimiters, but note that when a flag takes more than one argument, a
matched pair of delimiters must surround each argument.</p>
<ul>
<li>
<p><code>p</code><br />
Recognize the same escape sequences as the <code>print</code> builtin in string
arguments to any of the flags described below that follow this
argument.</p>
<p>Alternatively, with this option string arguments may be in the form
<code>$``var</code> in which case the value of the variable is substituted.
Note this form is strict; the string argument does not undergo
general parameter expansion.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">sep=:
val=a:b:c
print ${(ps.$sep.)val}
</code></pre>
</div>
<p>splits the variable on a <code>:</code>.</p>
</li>
<li>
<p><code>~</code><br />
Strings inserted into the expansion by any of the flags below are to
be treated as patterns. This applies to the string arguments of
flags that follow <code>~</code> within the same set of parentheses. Compare
with <code>~</code> outside parentheses, which forces the entire substituted
string to be treated as a pattern. Hence, for example,</p>
<div class="example">
<pre><code class="language-example">[[ &quot;?&quot; = ${(~j.|.)array} ]]
</code></pre>
</div>
<p>treats ‘<code>|</code>’ as a pattern and succeeds if and only if <code>$array</code>
contains the string ‘<code>?</code>’ as an element. The <code>~</code> may be repeated to
toggle the behaviour; its effect only lasts to the end of the
parenthesised group.</p>
</li>
<li>
<p><code>j:``string``:</code><br />
Join the words of arrays together using <code>string</code> as a separator.
<span id="index-SH_005fWORD_005fSPLIT_002c-use-of"></span> Note that
this occurs before field splitting by the <code>s:``string``:</code> flag or
the <code>SH_WORD_SPLIT</code> option.</p>
</li>
<li>
<p><code>l:``expr``::``string1``::``string2``:</code><br />
Pad the resulting words on the left. Each word will be truncated if
required and placed in a field <code>expr</code> characters wide.</p>
<p>The arguments <code>:``string1``:</code> and <code>:``string2``:</code> are optional;
neither, the first, or both may be given. Note that the same pairs
of delimiters must be used for each of the three arguments. The
space to the left will be filled with <code>string1</code> (concatenated as
often as needed) or spaces if <code>string1</code> is not given. If both
<code>string1</code> and <code>string2</code> are given, <code>string2</code> is inserted once
directly to the left of each word, truncated if necessary, before
<code>string1</code> is used to produce any remaining padding.</p>
<p>If either of <code>string1</code> or <code>string2</code> is present but empty, i.e. there
are two delimiters together at that point, the first character of
<code>$IFS</code> is used instead.</p>
<p>If the <code>MULTIBYTE</code> option is in effect, the flag <code>m</code> may also be
given, in which case widths will be used for the calculation of
padding; otherwise individual multibyte characters are treated as
occupying one unit of width.</p>
<p>If the <code>MULTIBYTE</code> option is not in effect, each byte in the string
is treated as occupying one unit of width.</p>
<p>Control characters are always assumed to be one unit wide; this
allows the mechanism to be used for generating repetitions of
control characters.</p>
</li>
<li>
<p><code>m</code><br />
Only useful together with one of the flags <code>l</code> or <code>r</code> or with the
<code>#</code> length operator when the <code>MULTIBYTE</code> option is in effect. Use
the character width reported by the system in calculating how much
of the string it occupies or the overall unit, however certain Asian
character sets and certain special effects use wider characters;
combining characters have zero width. would actually be displayed
will vary.</p>
<p>If the <code>m</code> is repeated, the character either counts zero (if it has
effect of counting the number of glyphs (visibly separate
characters), except for the case where combining characters
themselves have non-zero width (true in certain alphabets).</p>
</li>
<li>
<p><code>r:``expr``::``string1``::``string2``:</code><br />
As <code>l</code>, but pad the words on the right and insert <code>string2</code>
immediately to the right of the string to be padded.</p>
<p>Left and right padding may be used together. In this case the
strategy is to apply left padding to the first half width of each of
the resulting words, and right padding to the second half. If the
string to be padded has odd width the extra padding is applied on
the left.</p>
</li>
<li>
<p><code>s:``string``:</code><br />
Force field splitting at the separator <code>string</code>. Note that a
<code>string</code> of two or more characters means that all of them must match
in sequence; this differs from the treatment of two or more
characters in the <code>IFS</code> parameter. See also the <code>=</code> flag and the
<code>SH_WORD_SPLIT</code> option. An empty string may also be given in which
case every character will be a separate element.</p>
<p>For historical reasons, the usual behaviour that empty array
elements are retained inside double quotes is disabled for arrays
generated by splitting; hence the following:</p>
<div class="example">
<pre><code class="language-example">line=&quot;one::three&quot;
print -l &quot;${(s.:.)line}&quot;
</code></pre>
</div>
<p>produces two lines of output for <code>one</code> and <code>three</code> and elides the
empty field. To override this behaviour, supply the ‘<code>(@)</code>’ flag as
well, i.e. <code>&quot;${(@s.:.)line}&quot;</code>.</p>
</li>
<li>
<p><code>Z:``opts``:</code><br />
As <code>z</code> but takes a combination of option letters between a following
pair of delimiter characters. With no options the effect is
identical to <code>z</code>. <code>(Z+c+)</code> causes comments to be parsed as a string
and retained; any field in the resulting array beginning with an
unquoted comment character is a comment. <code>(Z+C+)</code> causes comments to
be parsed and removed. The rule for comments is standard: anything
between a word starting with the third character of <code>$HISTCHARS</code>,
default <code>#</code>, up to the next newline is a comment. <code>(Z+n+)</code> causes
unquoted newlines to be treated as ordinary whitespace, else they
are treated as if they are shell code delimiters and converted to
semicolons. Options are combined within the same set of delimiters,
e.g. <code>(Z+Cn+)</code>.</p>
</li>
<li>
<p><code>_:``flags``:</code><br />
The underscore (<code>_</code>) flag is reserved for future use. As of this
revision of zsh, there are no valid <code>flags</code>; anything following an
underscore, other than an empty pair of delimiters, is treated as an
error, and the flag itself has no effect.</p>
</li>
</ul>
<p>The following flags are meaningful with the <code>${</code>...<code>#</code>...<code>}</code> or
<code>${</code>...<code>%</code>...<code>}</code> forms. The <code>S</code> and <code>I</code> flags may also be used with the
<code>${</code>...<code>/</code>...<code>}</code> forms.</p>
<ul>
<li>
<p><code>S</code><br />
With <code>#</code> or <code>##</code>, search for the match that starts closest to the
start of the string (a ‘substring match’). Of all matches at a
particular position, <code>#</code> selects the shortest and <code>##</code> the longest:</p>
<div class="example">
<pre><code class="language-example">% str=&quot;aXbXc&quot;
% echo ${(S)str#X*}
abXc
% echo ${(S)str##X*}
a
%
</code></pre>
</div>
<p>With <code>%</code> or <code>%%</code>, search for the match that starts closest to the
end of the string:</p>
<div class="example">
<pre><code class="language-example">% str=&quot;aXbXc&quot;
% echo ${(S)str%X*}
aXbc
% echo ${(S)str%%X*}
aXb
%
</code></pre>
</div>
<p>(Note that <code>%</code> and <code>%%</code> don’t search for the match that ends closest
to the end of the string, as one might expect.)</p>
<p>With substitution via <code>${</code>...<code>/</code>...<code>}</code> or <code>${</code>...<code>//</code>...<code>}</code>,
specifies non-greedy matching, i.e. that the shortest instead of the
longest match should be replaced:</p>
<div class="example">
<pre><code class="language-example">% str=&quot;abab&quot;
% echo ${str/*b/_}
_
% echo ${(S)str/*b/_}
_ab
%
</code></pre>
</div>
</li>
<li>
<p><code>I:``expr``:</code><br />
Search the <code>expr</code>th match (where <code>expr</code> evaluates to a number). This
only applies when searching for substrings, either with the <code>S</code>
flag, or with <code>${</code>...<code>/</code>...<code>}</code> (only the <code>expr</code>th match is
substituted) or <code>${</code>...<code>//</code>...<code>}</code> (all matches from the <code>expr</code>th on
are substituted). The default is to take the first match.</p>
<p>The <code>expr</code>th match is counted such that there is either one or zero
matches from each starting position in the string, although for
global substitution matches overlapping previous replacements are
ignored. With the <code>${</code>...<code>%</code>...<code>}</code> and <code>${</code>...<code>%%</code>...<code>}</code> forms, the
starting position for the match moves backwards from the end as the
index increases, while with the other forms it moves forward from
the start.</p>
<p>Hence with the string</p>
<div class="example">
<pre><code class="language-example">which switch is the right switch for Ipswich?
</code></pre>
</div>
<p>substitutions of the form <code>${</code>(<code>SI:``N``:</code>)<code>string#w*ch}</code> as <code>N</code>
increases from 1 will match and remove ‘<code>which</code>’, ‘<code>witch</code>’,
‘<code>witch</code>’ and ‘<code>wich</code>’; the form using ‘<code>##</code>’ will match and
remove ‘<code>which switch is the right switch for Ipswich</code>’, ‘<code>witch is the right switch for Ipswich</code>’, ‘<code>witch for Ipswich</code>’ and ‘<code>wich</code>’.
The form using ‘<code>%</code>’ will remove the same matches as for ‘<code>#</code>’, but
in reverse order, and the form using ‘<code>%%</code>’ will remove the same
matches as for ‘<code>##</code>’ in reverse order.</p>
</li>
<li>
<p><code>B</code><br />
Include the index of the beginning of the match in the result.</p>
</li>
<li>
<p><code>E</code><br />
Include the index one character past the end of the match in the
result (note this is inconsistent with other uses of parameter
index).</p>
</li>
<li>
<p><code>M</code><br />
Include the matched portion in the result.</p>
</li>
<li>
<p><code>N</code><br />
Include the length of the match in the result.</p>
</li>
<li>
<p><code>R</code><br />
Include the unmatched portion in the result (the <em>R</em>est).</p>
</li>
</ul>
<hr />
<p><span id="Rules"></span></p>
<h3 id="1432-rules"><a class="header" href="#1432-rules">14.3.2 Rules</a></h3>
<p>Here is a summary of the rules for substitution; this assumes that
braces are present around the substitution, i.e. <code>${``...``}</code>. Some
particular examples are given below. Note that the Zsh Development Group
accepts <em>no responsibility</em> for any brain damage which may occur during
the reading of the following rules.</p>
<ul>
<li>
<p><code>1.</code> <em>Nested substitution</em><br />
If multiple nested <code>${``...``}</code> forms are present, substitution is
performed from the inside outwards. At each level, the substitution
takes account of whether the current value is a scalar or an array,
whether the whole substitution is in double quotes, and what flags
are supplied to the current level of substitution, just as if the
nested substitution were the outermost. The flags are not propagated
up to enclosing substitutions; the nested substitution will return
either a scalar or an array as determined by the flags, possibly
adjusted for quoting. All the following steps take place where
applicable at all levels of substitution.</p>
<p>Note that, unless the ‘<code>(P)</code>’ flag is present, the flags and any
subscripts apply directly to the value of the nested substitution;
for example, the expansion <code>${${foo}}</code> behaves exactly the same as
<code>${foo}</code>. When the ‘<code>(P)</code>’ flag is present in a nested substitution,
the other substitution rules are applied to the value <em>before</em> it is
interpreted as a name, so <code>${${(P)foo}}</code> may differ from
<code>${(P)foo}</code>.</p>
<p>At each nested level of substitution, the substituted words undergo
all forms of single-word substitution (i.e. not filename
generation), including command substitution, arithmetic expansion
and filename expansion (i.e. leading <code>~</code> and <code>=</code>). Thus, for
example, <code>${${:-=cat}:h}</code> expands to the directory where the <code>cat</code>
program resides. (Explanation: the internal substitution has no
parameter but a default value <code>=cat</code>, which is expanded by filename
expansion to a full path; the outer substitution then applies the
modifier <code>:h</code> and takes the directory part of the path.)</p>
</li>
<li>
<p><code>2.</code> <em>Internal parameter flags</em><br />
Any parameter flags set by one of the <code>typeset</code> family of commands,
in particular the <code>-L</code>, <code>-R</code>, <code>-Z</code>, <code>-u</code> and <code>-l</code> options for
padding and capitalization, are applied directly to the parameter
value. Note these flags are options to the command, e.g. ‘<code>typeset -Z</code>’; they are not the same as the flags used within parameter
substitutions.</p>
<p>At the outermost level of substitution, the ‘<code>(P)</code>’ flag (rule <code>4.</code>)
ignores these transformations and uses the unmodified value of the
parameter as the name to be replaced. This is usually the desired
behavior because padding may make the value syntactically illegal as
a parameter name, but if capitalization changes are desired, use the
<code>${${(P)foo}}</code> form (rule <code>25.</code>).</p>
</li>
<li>
<p><code>3.</code> <em>Parameter subscripting</em><br />
If the value is a raw parameter reference with a subscript, such as
<code>${``var``[3]}</code>, the effect of subscripting is applied directly to
the parameter. Subscripts are evaluated left to right; subsequent
subscripts apply to the scalar or array value yielded by the
previous subscript. Thus if <code>var</code> is an array, <code>${var[1][2]}</code> is the
second character of the first word, but <code>${var[2,4][2]}</code> is the
entire third word (the second word of the range of words two through
four of the original array). Any number of subscripts may appear.
Flags such as ‘<code>(k)</code>’ and ‘<code>(v)</code>’ which alter the result of
subscripting are applied.</p>
</li>
<li>
<p><code>4.</code> <em>Parameter name replacement</em><br />
At the outermost level of nesting only, the ‘<code>(P)</code>’ flag is applied.
This treats the value so far as a parameter name (which may include
a subscript expression) and replaces that with the corresponding
value. This replacement occurs later if the ‘<code>(P)</code>’ flag appears in
a nested substitution.</p>
<p>If the value so far names a parameter that has internal flags (rule
<code>2.</code>), those internal flags are applied to the new value after
replacement.</p>
</li>
<li>
<p><code>5.</code> <em>Double-quoted joining</em><br />
If the value after this process is an array, and the substitution
appears in double quotes, and neither an ‘<code>(@)</code>’ flag nor a ‘<code>#</code>’
length operator is present at the current level, then words of the
value are joined with the first character of the parameter <code>$IFS</code>,
by default a space, between each word (single word arrays are not
modified). If the ‘<code>(j)</code>’ flag is present, that is used for joining
instead of <code>$IFS</code>.</p>
</li>
<li>
<p><code>6.</code> <em>Nested subscripting</em><br />
Any remaining subscripts (i.e. of a nested substitution) are
evaluated at this point, based on whether the value is an array or a
scalar. As with <code>3.</code>, multiple subscripts can appear. Note that
<code>${foo[2,4][2]}</code> is thus equivalent to <code>${${foo[2,4]}[2]}</code> and also
to <code>&quot;${${(@)foo[2,4]}[2]}&quot;</code> (the nested substitution returns an
array in both cases), but not to <code>&quot;${${foo[2,4]}[2]}&quot;</code> (the nested
substitution returns a scalar because of the quotes).</p>
</li>
<li>
<p><code>7.</code> <em>Modifiers</em><br />
Any modifiers, as specified by a trailing ‘<code>#</code>’, ‘<code>%</code>’, ‘<code>/</code>’
(possibly doubled) or by a set of modifiers of the form ‘<code>:...</code>’
(see <a href="Expansion.html#Modifiers">Modifiers</a> in <a href="Expansion.html#History-Expansion">History
Expansion</a>), are applied to the words of the
value at this level.</p>
</li>
<li>
<p><code>8.</code> <em>Character evaluation</em><br />
Any ‘<code>(#)</code>’ flag is applied, evaluating the result so far
numerically as a character.</p>
</li>
<li>
<p><code>9.</code> <em>Length</em><br />
Any initial ‘<code>#</code>’ modifier, i.e. in the form <code>${#``var``}</code>, is used
to evaluate the length of the expression so far.</p>
</li>
<li>
<p><code>10.</code> <em>Forced joining</em><br />
If the ‘<code>(j)</code>’ flag is present, or no ‘<code>(j)</code>’ flag is present but
the string is to be split as given by rule <code>11.</code>, and joining did
not take place at rule <code>5.</code>, any words in the value are joined
together using the given string or the first character of <code>$IFS</code> if
none. Note that the ‘<code>(F)</code>’ flag implicitly supplies a string for
joining in this manner.</p>
</li>
<li>
<p><code>11.</code> <em>Simple word splitting</em><br />
If one of the ‘<code>(s)</code>’ or ‘<code>(f)</code>’ flags are present, or the ‘<code>=</code>’
specifier was present (e.g. <code>${=``var``}</code>), the word is split on
occurrences of the specified string, or (for <code>=</code> with neither of the
two flags present) any of the characters in <code>$IFS</code>.</p>
<p>If no ‘<code>(s)</code>’, ‘<code>(f)</code>’ or ‘<code>=</code>’ was given, but the word is not
quoted and the option <code>SH_WORD_SPLIT</code> is set, the word is split on
occurrences of any of the characters in <code>$IFS</code>. Note this step, too,
takes place at all levels of a nested substitution.</p>
</li>
<li>
<p><code>12.</code> <em>Case modification</em><br />
Any case modification from one of the flags ‘<code>(L)</code>’, ‘<code>(U)</code>’ or
‘<code>(C)</code>’ is applied.</p>
</li>
<li>
<p><code>13.</code> <em>Escape sequence replacement</em><br />
First any replacements from the ‘<code>(g)</code>’ flag are performed, then any
prompt-style formatting from the ‘<code>(%)</code>’ family of flags is applied.</p>
</li>
<li>
<p><code>14.</code> <em>Quote application</em><br />
Any quoting or unquoting using ‘<code>(q)</code>’ and ‘<code>(Q)</code>’ and related flags
is applied.</p>
</li>
<li>
<p><code>15.</code> <em>Directory naming</em><br />
Any directory name substitution using ‘<code>(D)</code>’ flag is applied.</p>
</li>
<li>
<p><code>16.</code> <em>Visibility enhancement</em><br />
Any modifications to make characters visible using the ‘<code>(V)</code>’ flag
are applied.</p>
</li>
<li>
<p><code>17.</code> <em>Lexical word splitting</em><br />
If the ’<code>(z)</code>’ flag or one of the forms of the ’<code>(Z)</code>’ flag is
present, the word is split as if it were a shell command line, so
that quotation marks and other metacharacters are used to decide
what constitutes a word. Note this form of splitting is entirely
distinct from that described by rule <code>11.</code>: it does not use <code>$IFS</code>,
and does not cause forced joining.</p>
</li>
<li>
<p><code>18.</code> <em>Uniqueness</em><br />
If the result is an array and the ‘<code>(u)</code>’ flag was present,
duplicate elements are removed from the array.</p>
</li>
<li>
<p><code>19.</code> <em>Ordering</em><br />
If the result is still an array and one of the ‘<code>(o)</code>’ or ‘<code>(O)</code>’
flags was present, the array is reordered.</p>
</li>
<li>
<p><code>20.</code> <code>RC_EXPAND_PARAM</code><br />
At this point the decision is made whether any resulting array
elements are to be combined element by element with surrounding
text, as given by either the <code>RC_EXPAND_PARAM</code> option or the ‘<code>^</code>’
flag.</p>
</li>
<li>
<p><code>21.</code> <em>Re-evaluation</em><br />
Any ‘<code>(e)</code>’ flag is applied to the value, forcing it to be
re-examined for new parameter substitutions, but also for command
and arithmetic substitutions.</p>
</li>
<li>
<p><code>22.</code> <em>Padding</em><br />
Any padding of the value by the ‘<code>(l.``fill``.)</code>’ or
‘<code>(r.``fill``.)</code>’ flags is applied.</p>
</li>
<li>
<p><code>23.</code> <em>Semantic joining</em><br />
In contexts where expansion semantics requires a single word to
result, all words are rejoined with the first character of <code>IFS</code>
between. So in ‘<code>${(P``)${(f``)lines}}</code>’ the value of <code>${lines}</code> is
split at newlines, but then must be joined again before the ‘<code>(P)</code>’
flag can be applied.</p>
<p>If a single word is not required, this rule is skipped.</p>
</li>
<li>
<p><code>24.</code> <em>Empty argument removal</em><br />
If the substitution does not appear in double quotes, any resulting
zero-length argument, whether from a scalar or an element of an
array, is elided from the list of arguments inserted into the
command line.</p>
<p>Strictly speaking, the removal happens later as the same happens
with other forms of substitution; the point to note here is simply
that it occurs after any of the above parameter operations.</p>
</li>
<li>
<p><code>25.</code> <em>Nested parameter name replacement</em><br />
If the ‘<code>(P)</code>’ flag is present and rule <code>4.</code> has not applied, the
value so far is treated as a parameter name (which may include a
subscript expression) and replaced with the corresponding value,
with internal flags (rule <code>2.</code>) applied to the new value.</p>
</li>
</ul>
<hr />
<p><span id="Examples-1"></span></p>
<h3 id="1433-examples"><a class="header" href="#1433-examples">14.3.3 Examples</a></h3>
<p>The flag <code>f</code> is useful to split a double-quoted substitution line by
line. For example, <code>${(f)&quot;$(&lt;``file``)&quot;}</code> substitutes the contents of
<code>file</code> divided so that each line is an element of the resulting array.
Compare this with the effect of <code>$``(&lt;``file``)</code> alone, which divides
the file up by words, or the same inside double quotes, which makes the
entire content of the file a single string.</p>
<p>The following illustrates the rules for nested parameter expansions.
Suppose that <code>$foo</code> contains the array <code>(bar baz``)</code>:</p>
<ul>
<li>
<p><code>&quot;${(@)${foo}[1]}&quot;</code><br />
This produces the result <code>b</code>. First, the inner substitution
<code>&quot;${foo}&quot;</code>, which has no array (<code>@</code>) flag, produces a single word
result <code>&quot;bar baz&quot;</code>. The outer substitution <code>&quot;${(@)...[1]}&quot;</code> detects
that this is a scalar, so that (despite the ‘<code>(@)</code>’ flag) the
subscript picks the first character.</p>
</li>
<li>
<p><code>&quot;${${(@)foo}[1]}&quot;</code><br />
This produces the result ‘<code>bar</code>’. In this case, the inner
substitution <code>&quot;${(@)foo}&quot;</code> produces the array ‘<code>(bar baz``)</code>’. The
outer substitution <code>&quot;${...[1]}&quot;</code> detects that this is an array and
picks the first word. This is similar to the simple case
<code>&quot;${foo[1]}&quot;</code>.</p>
</li>
</ul>
<p>As an example of the rules for word splitting and joining, suppose
<code>$foo</code> contains the array ‘<code>(ax1 bx1``)</code>’. Then</p>
<ul>
<li>
<p><code>${(s/x/)foo}</code><br />
produces the words ‘<code>a</code>’, ‘<code>1 b</code>’ and ‘<code>1</code>’.</p>
</li>
<li>
<p><code>${(j/x/s/x/)foo}</code><br />
produces ‘<code>a</code>’, ‘<code>1</code>’, ‘<code>b</code>’ and ‘<code>1</code>’.</p>
</li>
<li>
<p><code>${(s/x/)foo%%1*}</code><br />
produces ‘<code>a</code>’ and ‘<code> b</code>’ (note the extra space). As substitution
occurs before either joining or splitting, the operation first
generates the modified array <code>(ax bx``)</code>, which is joined to give
<code>&quot;ax bx&quot;</code>, and then split to give ‘<code>a</code>’, ‘<code> b</code>’ and ‘’. The final
empty string will then be elided, as it is not in double quotes.</p>
</li>
</ul>
<hr />
<p><span id="Command-Substitution"></span>
<span id="Command-Substitution-1"></span></p>
<h2 id="144-command-substitution"><a class="header" href="#144-command-substitution">14.4 Command Substitution</a></h2>
<p><span id="index-command-substitution"></span>
<span id="index-substitution_002c-command"></span></p>
<p>A command enclosed in parentheses preceded by a dollar sign, like
‘<code>$(</code>...<code>)</code>’, or quoted with grave accents, like ‘<code>‘</code>...<code>‘</code>’, is
replaced with its standard output, with any trailing newlines deleted.
If the substitution is not enclosed in double quotes, the output is
broken into words using the <code>IFS</code> parameter.
<span id="index-IFS_002c-use-of-1"></span></p>
<p>The substitution ‘<code>$(cat</code> <code>foo``)</code>’ may be replaced by the faster
‘<code>$(&lt;``foo``)</code>’. In this case <code>foo</code> undergoes single word shell
expansions (<em>parameter expansion</em>, <em>command substitution</em> and
<em>arithmetic expansion</em>), but not filename generation.</p>
<p>If the option <code>GLOB_SUBST</code> is set, the result of any unquoted command
substitution, including the special form just mentioned, is eligible for
filename generation.</p>
<hr />
<p><span id="Arithmetic-Expansion"></span>
<span id="Arithmetic-Expansion-1"></span></p>
<h2 id="145-arithmetic-expansion"><a class="header" href="#145-arithmetic-expansion">14.5 Arithmetic Expansion</a></h2>
<p><span id="index-arithmetic-expansion"></span>
<span id="index-expansion_002c-arithmetic"></span></p>
<p>A string of the form ‘<code>$[``exp``]</code>’ or ‘<code>$((``exp``))</code>’ is substituted
with the value of the arithmetic expression <code>exp</code>. <code>exp</code> is subjected to
<em>parameter expansion</em>, <em>command substitution</em> and <em>arithmetic expansion</em>
before it is evaluated. See <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a>.</p>
<hr />
<p><span id="Brace-Expansion"></span> <span id="Brace-Expansion-1"></span></p>
<h2 id="146-brace-expansion"><a class="header" href="#146-brace-expansion">14.6 Brace Expansion</a></h2>
<p><span id="index-brace-expansion"></span>
<span id="index-expansion_002c-brace"></span></p>
<p>A string of the form ‘<code>foo``{``xx``,``yy``,``zz``}``bar</code>’ is expanded to
the individual words ‘<code>fooxxbar</code>’, ‘<code>fooyybar</code>’ and ‘<code>foozzbar</code>’.
Left-to-right order is preserved. This construct may be nested. Commas
may be quoted in order to include them literally in a word.</p>
<p>An expression of the form ‘<code>{``n1``..``n2``}</code>’, where <code>n1</code> and <code>n2</code> are
integers, is expanded to every number between <code>n1</code> and <code>n2</code> inclusive.
If either number begins with a zero, all the resulting numbers will be
padded with leading zeroes to that minimum width, but for negative
numbers the <code>-</code> character is also included in the width. If the numbers
are in decreasing order the resulting sequence will also be in
decreasing order.</p>
<p>An expression of the form ‘<code>{``n1``..``n2``..``n3``}</code>’, where <code>n1</code>,
<code>n2</code>, and <code>n3</code> are integers, is expanded as above, but only every <code>n3</code>th
number starting from <code>n1</code> is output. If <code>n3</code> is negative the numbers are
output in reverse order, this is slightly different from simply swapping
<code>n1</code> and <code>n2</code> in the case that the step <code>n3</code> doesn’t evenly divide the
range. Zero padding can be specified in any of the three numbers,
specifying it in the third can be useful to pad for example
‘<code>{-99..100..01}</code>’ which is not possible to specify by putting a 0 on
either of the first two numbers (i.e. pad to two characters).</p>
<p>An expression of the form ‘<code>{``c1``..``c2``}</code>’, where <code>c1</code> and <code>c2</code> are
single characters (which may be multibyte characters), is expanded to
every character in the range from <code>c1</code> to <code>c2</code> in whatever character
sequence is used internally. For characters with code points below 128
this is US ASCII (this is the only case most users will need). If any
intervening character is not If the character sequence is reversed, the
output is in reverse order, e.g. ‘<code>{d..a}</code>’ is substituted as ‘<code>d c b a</code>’.</p>
<p>If a brace expression matches none of the above forms, it is left
unchanged, unless the option <code>BRACE_CCL</code> (an abbreviation for ‘brace
character class’) is set.
<span id="index-BRACE_005fCCL_002c-use-of"></span> In that case, it is
expanded to a list of the individual characters between the braces
sorted into the order of the characters in the ASCII character set
(multibyte characters are not currently handled). The syntax is similar
to a <code>[</code>...<code>]</code> expression in filename generation: ‘<code>-</code>’ is treated
specially to denote a range of characters, but ‘<code>^</code>’ or ‘<code>!</code>’ as the
first character is treated normally. For example, ‘<code>{abcdef0-9}</code>’
expands to 16 words <code>0 1 2 3 4 5 6 7 8 9 a b c d e f</code>.</p>
<p>Note that brace expansion is not part of filename generation (globbing);
an expression such as <code>*/{foo,bar}</code> is split into two separate words
<code>*/foo</code> and <code>*/bar</code> before filename generation takes place. In
particular, note that this is liable to produce a ‘no match’ error if
<em>either</em> of the two expressions does not match; this is to be contrasted
with <code>*/(foo|bar)</code>, which is treated as a single pattern but otherwise
has similar effects.</p>
<p>To combine brace expansion with array expansion, see the <code>${^``spec``}</code>
form described in <a href="Expansion.html#Parameter-Expansion">Parameter Expansion</a> above.</p>
<hr />
<p><span id="Filename-Expansion"></span>
<span id="Filename-Expansion-1"></span></p>
<h2 id="147-filename-expansion"><a class="header" href="#147-filename-expansion">14.7 Filename Expansion</a></h2>
<p><span id="index-filename-expansion"></span>
<span id="index-expansion_002c-filename"></span></p>
<p>Each word is checked to see if it begins with an unquoted ‘<code>~</code>’. If it
does, then the word up to a ‘<code>/</code>’, or the end of the word if there is no
‘<code>/</code>’, is checked to see if it can be substituted in one of the ways
described here. If so, then the ‘<code>~</code>’ and the checked portion are
replaced with the appropriate substitute value.</p>
<p>A ‘<code>~</code>’ by itself is replaced by the value of <code>$HOME</code>. A ‘<code>~</code>’ followed
by a ‘<code>+</code>’ or a ‘<code>-</code>’ is replaced by current or previous working
directory, respectively.</p>
<p>A ‘<code>~</code>’ followed by a number is replaced by the directory at that
position in the directory stack. ‘<code>~0</code>’ is equivalent to ‘<code>~+</code>’, and
‘<code>~1</code>’ is the top of the stack. ‘<code>~+</code>’ followed by a number is
replaced by the directory at that position in the directory stack.
‘<code>~+0</code>’ is equivalent to ‘<code>~+</code>’, and ‘<code>~+1</code>’ is the top of the stack.
‘<code>~-</code>’ followed by a number is replaced by the directory that many
positions from the bottom of the stack. ‘<code>~-0</code>’ is the bottom of the
stack. <span id="index-PUSHD_005fMINUS_002c-use-of"></span> The
<code>PUSHD_MINUS</code> option exchanges the effects of ‘<code>~+</code>’ and ‘<code>~-</code>’ where
they are followed by a number.</p>
<hr />
<p><span id="Dynamic-named-directories"></span></p>
<h3 id="1471-dynamic-named-directories"><a class="header" href="#1471-dynamic-named-directories">14.7.1 Dynamic named directories</a></h3>
<p><span id="index-directories_002c-named_002c-dynamic"></span>
<span id="index-named-directories_002c-dynamic"></span>
<span id="index-dynamic-named-directories"></span></p>
<p>If the function <code>zsh_directory_name</code> exists, or the shell variable
<code>zsh_directory_name_functions</code> exists and contains an array of function
names, then the functions are used to implement dynamic directory
naming. The functions are tried in order until one returns status zero,
so it is important that functions test whether they can handle the case
in question and return an appropriate status.</p>
<p>A ‘<code>~</code>’ followed by a string <code>namstr</code> in unquoted square brackets is
treated specially as a dynamic directory name. Note that the first
unquoted closing square bracket always terminates <code>namstr</code>. The shell
function is passed two arguments: the string <code>n</code> (for name) and
<code>namstr</code>. It should either set the array <code>reply</code> to a single element
which is the directory corresponding to the name and return status zero
(executing an assignment as the last statement is usually sufficient),
or it should return status non-zero. In the former case the element of
reply is used as the directory; in the latter case the substitution is
deemed to have failed. If all functions fail and the option <code>NOMATCH</code> is
set, an error results.</p>
<p>The functions defined as above are also used to see if a directory can
be turned into a name, for example when printing the directory stack or
when expanding <code>%~</code> in prompts. In this case each function is passed two
arguments: the string <code>d</code> (for directory) and the candidate for dynamic
naming. The function should either return non-zero status, if the
directory cannot be named by the function, or it should set the array
reply to consist of two elements: the first is the dynamic name for the
directory (as would appear within ‘<code>~[``...``]</code>’), and the second is the
prefix length of the directory to be replaced. For example, if the trial
directory is <code>/home/myname/src/zsh</code> and the dynamic name for
<code>/home/myname/src</code> (which has 16 characters) is <code>s</code>, then the function
sets</p>
<div class="example">
<pre><code class="language-example">reply=(s 16)
</code></pre>
</div>
<p>The directory name so returned is compared with possible static names
for parts of the directory path, as described below; it is used if the
prefix length matched (16 in the example) is longer than that matched by
any static name.</p>
<p>It is not a requirement that a function implements both <code>n</code> and <code>d</code>
calls; for example, it might be appropriate for certain dynamic forms of
expansion not to be contracted to names. In that case any call with the
first argument <code>d</code> should cause a non-zero status to be returned.</p>
<p>The completion system calls ‘<code>zsh_directory_name c</code>’ followed by
equivalent calls to elements of the array
<code>zsh_directory_name_functions</code>, if it exists, in order to complete
dynamic names for directories. The code for this should be as for any
other completion function as described in <a href="Completion-System.html#Completion-System">Completion
System</a>.</p>
<p>As a working example, here is a function that expands any dynamic names
beginning with the string <code>p:</code> to directories below
<code>/home/pws/perforce</code>. In this simple case a static name for the
directory would be just as effective.</p>
<div class="example">
<pre><code class="language-example">zsh_directory_name() {
emulate -L zsh
setopt extendedglob
local -a match mbegin mend
if [[ $1 = d ]]; then
# turn the directory into a name
if [[ $2 = (#b)(/home/pws/perforce/)([^/]##)* ]]; then
typeset -ga reply
reply=(p:$match[2] $(( ${#match[1]} + ${#match[2]} )) )
else
return 1
fi
elif [[ $1 = n ]]; then
# turn the name into a directory
[[ $2 != (#b)p:(?*) ]] &amp;&amp; return 1
typeset -ga reply
reply=(/home/pws/perforce/$match[1])
elif [[ $1 = c ]]; then
# complete names
local expl
local -a dirs
dirs=(/home/pws/perforce/*(/:t))
dirs=(p:${^dirs})
_wanted dynamic-dirs expl 'dynamic directory' compadd -S\] -a dirs
return
else
return 1
fi
return 0
}
</code></pre>
</div>
<hr />
<p><span id="Static-named-directories"></span></p>
<h3 id="1472-static-named-directories"><a class="header" href="#1472-static-named-directories">14.7.2 Static named directories</a></h3>
<p><span id="index-directories_002c-named_002c-static"></span>
<span id="index-named-directories_002c-static"></span>
<span id="index-static-named-directories"></span></p>
<p>A ‘<code>~</code>’ followed by anything not already covered consisting of any
number of alphanumeric characters or underscore (‘<code>_</code>’), hyphen (‘<code>-</code>’),
or dot (‘<code>.</code>’) is looked up as a named directory, and replaced by the
value of that named directory if found. Named directories are typically
home directories for users on the system. They may also be defined if
the text after the ‘<code>~</code>’ is the name of a string shell parameter whose
value begins with a ‘<code>/</code>’. Note that trailing slashes will be removed
from the path to the directory (though the original parameter is not
modified).</p>
<p>It is also possible to define directory names using the <code>-d</code> option to
the <code>hash</code> builtin.</p>
<p>When the shell prints a path (e.g. when expanding <code>%~</code> in prompts or
when printing the directory stack), the path is checked to see if it has
a named directory as its prefix. If so, then the prefix portion is
replaced with a ‘<code>~</code>’ followed by the name of the directory. The shorter
of the two ways of referring to the directory is used, i.e. either the
directory name or the full path; the name is used if they are the same
length. The parameters <code>$PWD</code> and <code>$OLDPWD</code> are never abbreviated in
this fashion.</p>
<hr />
<p><span id="g_t_0060_003d_0027-expansion"></span></p>
<h3 id="1473--expansion"><a class="header" href="#1473--expansion">14.7.3 ‘=’ expansion</a></h3>
<p>If a word begins with an unquoted ‘<code>=</code>’ and the <code>EQUALS</code> option is set,
the remainder of the word is taken as the name of a command. If a
command exists by that name, the word is replaced by the full pathname
of the command.</p>
<hr />
<p><span id="Notes"></span></p>
<h3 id="1474-notes"><a class="header" href="#1474-notes">14.7.4 Notes</a></h3>
<p>Filename expansion is performed on the right hand side of a parameter
assignment, including those appearing after commands of the <code>typeset</code>
family. In this case, the right hand side will be treated as a
colon-separated list in the manner of the <code>PATH</code> parameter, so that a
‘<code>~</code>’ or an ‘<code>=</code>’ following a ‘<code>:</code>’ is eligible for expansion. All
such behaviour can be disabled by quoting the ‘<code>~</code>’, the ‘<code>=</code>’, or the
whole expression (but not simply the colon); the <code>EQUALS</code> option is also
respected.</p>
<p>If the option <code>MAGIC_EQUAL_SUBST</code> is set, any unquoted shell argument in
the form ‘<code>identifier``=``expression</code>’ becomes eligible for file
expansion as described in the previous paragraph. Quoting the first
‘<code>=</code>’ also inhibits this.</p>
<hr />
<p><span id="Filename-Generation"></span>
<span id="Filename-Generation-1"></span></p>
<h2 id="148-filename-generation"><a class="header" href="#148-filename-generation">14.8 Filename Generation</a></h2>
<p><span id="index-filename-generation"></span></p>
<p>If a word contains an unquoted instance of one of the characters ‘<code>*</code>’,
‘<code>(</code>’, ‘<code>|</code>’, ‘<code>&lt;</code>’, ‘<code>[</code>’, or ‘<code>?</code>’, it is regarded as a pattern for
filename generation, unless the <code>GLOB</code> option is unset.
<span id="index-GLOB_002c-use-of"></span> If the <code>EXTENDED_GLOB</code> option
is set, <span id="index-EXTENDED_005fGLOB_002c-use-of"></span> the ‘<code>^</code>’
and ‘<code>#</code>’ characters also denote a pattern; otherwise they are not
treated specially by the shell.</p>
<p>The word is replaced with a list of sorted filenames that match the
pattern. If no matching pattern is found, the shell gives an error
message, unless the <code>NULL_GLOB</code> option is set,
<span id="index-NULL_005fGLOB_002c-use-of"></span> in which case the
word is deleted; or unless the <code>NOMATCH</code> option is unset, in which case
the word is left unchanged. <span id="index-NOMATCH_002c-use-of"></span></p>
<p>In filename generation, the character ‘<code>/</code>’ must be matched explicitly;
also, a ‘<code>.</code>’ must be matched explicitly at the beginning of a pattern
or after a ‘<code>/</code>’, unless the <code>GLOB_DOTS</code> option is set.
<span id="index-GLOB_005fDOTS_002c-use-of"></span> No filename
generation pattern matches the files ‘<code>.</code>’ or ‘<code>..</code>’. In other instances
of pattern matching, the ‘<code>/</code>’ and ‘<code>.</code>’ are not treated specially.</p>
<hr />
<p><span id="Glob-Operators"></span></p>
<h3 id="1481-glob-operators"><a class="header" href="#1481-glob-operators">14.8.1 Glob Operators</a></h3>
<ul>
<li>
<p><code>*</code><br />
Matches any string, including the null string.</p>
</li>
<li>
<p><code>?</code><br />
Matches any character.</p>
</li>
<li>
<p><code>[</code>...<code>]</code><br />
Matches any of the enclosed characters. Ranges of characters can be
specified by separating two characters by a ‘<code>-</code>’. A ‘<code>-</code>’ or ‘<code>]</code>’
may be matched by including it as the first character in the list.
<span id="index-character-classes"></span> There are also several
named classes of characters, in the form ‘<code>[:``name``:]</code>’ with the
following meanings. The first set use the macros provided by the
operating system to test for the given character combinations,
including any modifications due to local language settings, see man
page ctype(3):</p>
<ul>
<li>
<p><code>[:alnum:]</code><br />
The character is alphanumeric</p>
</li>
<li>
<p><code>[:alpha:]</code><br />
The character is alphabetic</p>
</li>
<li>
<p><code>[:ascii:]</code><br />
The character is 7-bit, i.e. is a single-byte character without
the top bit set.</p>
</li>
<li>
<p><code>[:blank:]</code><br />
The character is a blank character</p>
</li>
<li>
<p><code>[:cntrl:]</code><br />
The character is a control character</p>
</li>
<li>
<p><code>[:digit:]</code><br />
The character is a decimal digit</p>
</li>
<li>
<p><code>[:graph:]</code><br />
<code>[:lower:]</code><br />
The character is a lowercase letter</p>
</li>
<li>
<p><code>[:print:]</code><br />
<code>[:punct:]</code><br />
<code>[:space:]</code><br />
The character is whitespace</p>
</li>
<li>
<p><code>[:upper:]</code><br />
The character is an uppercase letter</p>
</li>
<li>
<p><code>[:xdigit:]</code><br />
The character is a hexadecimal digit</p>
</li>
</ul>
<p>Another set of named classes is handled internally by the shell and
is not sensitive to the locale:</p>
<ul>
<li>
<p><code>[:IDENT:]</code><br />
The character is allowed to form part of a shell identifier,
such as a parameter name</p>
</li>
<li>
<p><code>[:IFS:]</code><br />
The character is used as an input field separator, i.e. is
contained in the <code>IFS</code> parameter</p>
</li>
<li>
<p><code>[:IFSSPACE:]</code><br />
The character is an IFS white space character; see the
documentation for <code>IFS</code> in <a href="Parameters.html#Parameters-Used-By-The-Shell">Parameters Used By The
Shell</a>.</p>
</li>
<li>
<p><code>[:INCOMPLETE:]</code><br />
Matches a byte that starts an incomplete multibyte character.
Note that there may be a sequence of more than one bytes that
taken together form the prefix of a multibyte character. To test
for a potentially incomplete byte sequence, use the pattern
‘<code>[[:INCOMPLETE:]]*</code>’. This will never match a sequence
starting with a valid multibyte character.</p>
</li>
<li>
<p><code>[:INVALID:]</code><br />
Matches a byte that does not start a valid multibyte character.
Note this may be a continuation byte of an incomplete multibyte
character as any part of a multibyte string consisting of
invalid and incomplete multibyte characters is treated as single
bytes.</p>
</li>
<li>
<p><code>[:WORD:]</code><br />
The character is treated as part of a word; this test is
sensitive to the value of the <code>WORDCHARS</code> parameter</p>
</li>
</ul>
<p>Note that the square brackets are additional to those enclosing the
whole set of characters, so to test for a single alphanumeric
character you need ‘<code>[[:alnum:]]</code>’. Named character sets can be used
alongside other types, e.g. ‘<code>[[:alpha:]0-9]</code>’.</p>
</li>
<li>
<p><code>[^</code>...<code>]</code><br />
<code>[!</code>...<code>]</code><br />
Like <code>[</code>...<code>]</code>, except that it matches any character which is not in
the given set.</p>
</li>
<li>
<p><code>&lt;</code>[<code>x</code>]<code>-</code>[<code>y</code>]<code>&gt;</code><br />
Matches any number in the range <code>x</code> to <code>y</code>, inclusive. Either of the
numbers may be omitted to make the range open-ended; hence ‘<code>&lt;-&gt;</code>’
matches any number. To match individual digits, the <code>[</code>...<code>]</code> form
is more efficient.</p>
<p>Be careful when using other wildcards adjacent to patterns of this
form; for example, <code>&lt;0-9&gt;*</code> will actually match any number
whatsoever at the start of the string, since the ‘<code>&lt;0-9&gt;</code>’ will
match the first digit, and the ‘<code>*</code>’ will match any others. This is
a trap for the unwary, but is match always succeeds. Expressions
such as ‘<code>&lt;0-9&gt;[^[:digit:]]*</code>’ can be used instead.</p>
</li>
<li>
<p><code>(</code>...<code>)</code><br />
Matches the enclosed pattern. This is used for grouping. If the
<code>KSH_GLOB</code> option is set, then a ‘<code>@</code>’, ‘<code>*</code>’, ‘<code>+</code>’, ‘<code>?</code>’ or ‘<code>!</code>’
immediately preceding the ‘<code>(</code>’ is treated specially, as detailed
below. The option <code>SH_GLOB</code> prevents bare parentheses from being
used in this way, though the <code>KSH_GLOB</code> option is still available.</p>
<p>Note that grouping cannot extend over multiple directories: it is an
error to have a ‘<code>/</code>’ within a group (this only applies for patterns
used in filename generation). There is one exception: a group of the
form <code>(``pat``/)#</code> appearing as a complete path segment can match a
sequence of directories. For example, <code>foo/(a*/)#bar</code> matches
<code>foo/bar</code>, <code>foo/any/bar</code>, <code>foo/any/anyother/bar</code>, and so on.</p>
</li>
<li>
<p><code>x``|``y</code><br />
Matches either <code>x</code> or <code>y</code>. This operator has lower precedence than
any other. The ‘<code>|</code>’ character must be within parentheses, to avoid
interpretation as a pipeline. The alternatives are tried in order
from left to right.</p>
</li>
<li>
<p><code>^``x</code><br />
(Requires <code>EXTENDED_GLOB</code> to be set.) Matches anything except the
pattern <code>x</code>. This has a higher precedence than ‘<code>/</code>’, so
‘<code>^foo/bar</code>’ will search directories in ‘<code>.</code>’ except ‘<code>./foo</code>’
for a file named ‘<code>bar</code>’.</p>
</li>
<li>
<p><code>x``~``y</code><br />
(Requires <code>EXTENDED_GLOB</code> to be set.) Match anything that matches
the pattern <code>x</code> but does not match <code>y</code>. This has lower precedence
than any operator except ‘<code>|</code>’, so ‘<code>*/*~foo/bar</code>’ will search for
all files in all directories in ‘<code>.</code>’ and then exclude ‘<code>foo/bar</code>’
if there was such a match. Multiple patterns can be excluded by
‘<code>foo``~``bar``~``baz</code>’. In the exclusion pattern (<code>y</code>), ‘<code>/</code>’ and
‘<code>.</code>’ are not treated specially the way they usually are in
globbing.</p>
</li>
<li>
<p><code>x``#</code><br />
(Requires <code>EXTENDED_GLOB</code> to be set.) Matches zero or more
occurrences of the pattern <code>x</code>. This operator has high precedence;
‘<code>12#</code>’ is equivalent to ‘<code>1(2#)</code>’, rather than ‘<code>(12)#</code>’. It is
an error for an unquoted ‘<code>#</code>’ to follow something which cannot be
repeated; this includes an empty string, a pattern already followed
by ‘<code>##</code>’, or parentheses when part of a <code>KSH_GLOB</code> pattern (for
example, ‘<code>!(``foo``)#</code>’ is invalid and must be replaced by
‘<code>*(!(``foo``))</code>’).</p>
</li>
<li>
<p><code>x``##</code><br />
(Requires <code>EXTENDED_GLOB</code> to be set.) Matches one or more
occurrences of the pattern <code>x</code>. This operator has high precedence;
‘<code>12##</code>’ is equivalent to ‘<code>1(2##)</code>’, rather than ‘<code>(12)##</code>’. No
more than two active ‘<code>#</code>’ characters may appear together. (Note the
potential clash with glob qualifiers in the form ‘<code>1(2##)</code>’ which
should therefore be avoided.)</p>
</li>
</ul>
<hr />
<p><span id="ksh_002dlike-Glob-Operators"></span></p>
<h3 id="1482-ksh-like-glob-operators"><a class="header" href="#1482-ksh-like-glob-operators">14.8.2 ksh-like Glob Operators</a></h3>
<p><span id="index-KSH_005fGLOB_002c-use-of"></span></p>
<p>If the <code>KSH_GLOB</code> option is set, the effects of parentheses can be
modified by a preceding ‘<code>@</code>’, ‘<code>*</code>’, ‘<code>+</code>’, ‘<code>?</code>’ or ‘<code>!</code>’. This
character need not be unquoted to have special effects, but the ‘<code>(</code>’
must be.</p>
<ul>
<li>
<p><code>@(</code>...<code>)</code><br />
Match the pattern in the parentheses. (Like ‘<code>(</code>...<code>)</code>’.)</p>
</li>
<li>
<p><code>*(</code>...<code>)</code><br />
Match any number of occurrences. (Like ‘<code>(</code>...<code>)#</code>’, except that
recursive directory searching is not supported.)</p>
</li>
<li>
<p><code>+(</code>...<code>)</code><br />
Match at least one occurrence. (Like ‘<code>(</code>...<code>)##</code>’, except that
recursive directory searching is not supported.)</p>
</li>
<li>
<p><code>?(</code>...<code>)</code><br />
Match zero or one occurrence. (Like ‘<code>(|</code>...<code>)</code>’.)</p>
</li>
<li>
<p><code>!(</code>...<code>)</code><br />
Match anything but the expression in parentheses. (Like
‘<code>(^(</code>...<code>))</code>’.)</p>
</li>
</ul>
<hr />
<p><span id="Precedence"></span></p>
<h3 id="1483-precedence"><a class="header" href="#1483-precedence">14.8.3 Precedence</a></h3>
<p><span id="index-precedence-of-glob-operators"></span></p>
<p>The precedence of the operators given above is (highest) ‘<code>^</code>’, ‘<code>/</code>’,
‘<code>~</code>’, ‘<code>|</code>’ (lowest); the remaining operators are simply treated from
left to right as part of a string, with ‘<code>#</code>’ and ‘<code>##</code>’ applying to the
shortest possible preceding unit (i.e. a character, ‘<code>?</code>’, ‘<code>[</code>...<code>]</code>’,
‘<code>&lt;</code>...<code>&gt;</code>’, or a parenthesised expression). As mentioned above, a
‘<code>/</code>’ used as a directory separator may not appear inside parentheses,
while a ‘<code>|</code>’ must do so; in patterns used in other contexts than
filename generation (for example, in <code>case</code> statements and tests within
‘<code>[[</code>...<code>]]</code>’), a ‘<code>/</code>’ is not special; and ‘<code>/</code>’ is also not special
after a ‘<code>~</code>’ appearing outside parentheses in a filename pattern.</p>
<hr />
<p><span id="Globbing-Flags"></span></p>
<h3 id="1484-globbing-flags"><a class="header" href="#1484-globbing-flags">14.8.4 Globbing Flags</a></h3>
<p>There are various flags which affect any text to their right up to the
end of the enclosing group or to the end of the pattern; they require
the <code>EXTENDED_GLOB</code> option. All take the form <code>(#``X``)</code> where <code>X</code> may
have one of the following forms:</p>
<ul>
<li>
<p><code>i</code><br />
Case insensitive: upper or lower case characters in the pattern
match upper or lower case characters.</p>
</li>
<li>
<p><code>l</code><br />
Lower case characters in the pattern match upper or lower case
characters; upper case characters in the pattern still only match
upper case characters.</p>
</li>
<li>
<p><code>I</code><br />
Case sensitive: locally negates the effect of <code>i</code> or <code>l</code> from that
point on.</p>
<p><span id="index-match"></span> <span id="index-mbegin"></span>
<span id="index-mend"></span></p>
</li>
<li>
<p><code>b</code><br />
Activate backreferences for parenthesised groups in the pattern;
this does not work in filename generation. When a pattern with a set
of active parentheses is matched, the strings matched by the groups
are stored in the array <code>$match</code>, the indices of the beginning of
the matched parentheses in the array <code>$mbegin</code>, and the indices of
the end in the array <code>$mend</code>, with the first element of each array
corresponding to the first parenthesised group, and so on. These
arrays are not otherwise special to the shell. The indices use the
same convention as does parameter substitution, so that elements of
<code>$mend</code> and <code>$mbegin</code> may be used in subscripts; the <code>KSH_ARRAYS</code>
option is respected. Sets of globbing flags are not considered
parenthesised groups; only the first nine active parentheses can be
referenced.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">foo=&quot;a_string_with_a_message&quot;
if [[ $foo = (a|an)_(#b)(*) ]]; then
print ${foo[$mbegin[1],$mend[1]]}
fi
</code></pre>
</div>
<p>prints ‘<code>string_with_a_message</code>’. Note that the first set of
parentheses is before the <code>(#b)</code> and does not create a
backreference.</p>
<p>Backreferences work with all forms of pattern matching other than
filename generation, but note that when performing matches on an
entire array, such as <code>${``array``#``pattern``}</code>, or a global
substitution, such as <code>${``param``//``pat``/``repl``}</code>, only the
data for the last match remains available. In the case of global
replacements this may still be useful. See the example for the <code>m</code>
flag below.</p>
<p>The numbering of backreferences strictly follows the order of the
opening parentheses from left to right in the pattern string,
although sets of parentheses may be nested. There are special rules
for parentheses followed by ‘<code>#</code>’ or ‘<code>##</code>’. Only the last match of
the parenthesis is remembered: for example, in ‘<code>[[ abab = (#b)([ab])# ]]</code>’, only the final ‘<code>b</code>’ is stored in <code>match[1]</code>. Thus
extra parentheses may be necessary to match the complete segment:
for example, use ‘<code>X((ab|cd)#)Y</code>’ to match a whole string of either
‘<code>ab</code>’ or ‘<code>cd</code>’ between ‘<code>X</code>’ and ‘<code>Y</code>’, using the value of
<code>$match[1]</code> rather than <code>$match[2]</code>.</p>
<p>If the match fails none of the parameters is altered, so in some
cases it may be necessary to initialise them beforehand. If some of
the backreferences fail to match — which happens if they are in an
alternate branch which fails to match, or if they are followed by
<code>#</code> and matched zero times — then the matched string is set to the
empty string, and the start and end indices are set to -1.</p>
<p>Pattern matching with backreferences is slightly slower than
without.</p>
</li>
<li>
<p><code>B</code><br />
Deactivate backreferences, negating the effect of the <code>b</code> flag from
that point on.</p>
</li>
<li>
<p><code>c``N``,``M</code><br />
The flag <code>(#c``N``,``M``)</code> can be used anywhere that the <code>#</code> or <code>##</code>
operators can be used except in the expressions ‘<code>(*/)#</code>’ and
‘<code>(*/)##</code>’ in filename generation, where ‘<code>/</code>’ has special
meaning; it cannot be combined with other globbing flags and a bad
pattern error occurs if it is misplaced. It is equivalent to the
form <code>{``N``,``M``}</code> in regular expressions. The previous character
or group is required to match between <code>N</code> and <code>M</code> times, inclusive.
The form <code>(#c``N``)</code> requires exactly <code>N</code> matches; <code>(#c,``M``)</code> is
equivalent to specifying <code>N</code> as 0; <code>(#c``N``,)</code> specifies that there
is no maximum limit on the number of matches.</p>
<p><span id="index-MATCH"></span> <span id="index-MBEGIN"></span>
<span id="index-MEND"></span></p>
</li>
<li>
<p><code>m</code><br />
Set references to the match data for the entire string matched; this
is similar to backreferencing and does not work in filename
generation. The flag must be in effect at the end of the pattern,
i.e. not local to a group. The parameters <code>$MATCH</code>, <code>$MBEGIN</code> and
<code>$MEND</code> will be set to the string matched and to the indices of the
beginning and end of the string, respectively. This is most useful
in parameter substitutions, as otherwise the string matched is
obvious.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">arr=(veldt jynx grimps waqf zho buck)
print ${arr//(#m)[aeiou]/${(U)MATCH}}
</code></pre>
</div>
<p>forces all the matches (i.e. all vowels) into uppercase, printing
‘<code>vEldt jynx grImps wAqf zhO bUck</code>’.</p>
<p>Unlike backreferences, there is no speed penalty for using match
references, other than the extra substitutions required for the
replacement strings in cases such as the example shown.</p>
</li>
<li>
<p><code>M</code><br />
Deactivate the <code>m</code> flag, hence no references to match data will be
created.</p>
</li>
<li>
<p><code>a``num</code><br />
Approximate matching: <code>num</code> errors are allowed in the string matched
by the pattern. The rules for this are described in the next
subsection.</p>
</li>
<li>
<p><code>s</code>, <code>e</code><br />
Unlike the other flags, these have only a local effect, and each
must appear on its own: ‘<code>(#s)</code>’ and ‘<code>(#e)</code>’ are the only valid
forms. The ‘<code>(#s)</code>’ flag succeeds only at the start of the test
string, and the ‘<code>(#e)</code>’ flag succeeds only at the end of the test
string; they correspond to ‘<code>^</code>’ and ‘<code>$</code>’ in standard regular
expressions. They are useful for matching path segments in patterns
other than those in filename generation (where path segments are in
any case treated separately). For example,
‘<code>*((#s)|/)test((#e)|/)*</code>’ matches a path segment ‘<code>test</code>’ in
any of the following strings: <code>test</code>, <code>test/at/start</code>,
<code>at/end/test</code>, <code>in/test/middle</code>.</p>
<p>Another use is in parameter substitution; for example
‘<code>${array/(#s)A*Z(#e)}</code>’ will remove only elements of an array
which match the complete pattern ‘<code>A*Z</code>’. There are other ways of
performing many operations of this type, however the combination of
the substitution operations ‘<code>/</code>’ and ‘<code>//</code>’ with the ‘<code>(#s)</code>’ and
‘<code>(#e)</code>’ flags provides a single simple and memorable method.</p>
<p>Note that assertions of the form ‘<code>(^(#s))</code>’ also work, i.e. match
anywhere except at the start of the string, although this actually
means ‘anything except a zero-length portion at the start of the
string’; you need to use ‘<code>(&quot;&quot;~(#s))</code>’ to match a zero-length
portion of the string not at the start.</p>
</li>
<li>
<p><code>q</code><br />
A ‘<code>q</code>’ and everything up to the closing parenthesis of the globbing
flags are ignored by the pattern matching code. This is intended to
support the use of glob qualifiers, see below. The result is that
the pattern ‘<code>(#b)(*).c(#q.)</code>’ can be used both for globbing and for
matching against a string. In the former case, the ‘<code>(#q.)</code>’ will be
treated as a glob qualifier and the ‘<code>(#b)</code>’ will not be useful,
while in the latter case the ‘<code>(#b)</code>’ is useful for backreferences
and the ‘<code>(#q.)</code>’ will be ignored. Note that colon modifiers in the
glob qualifiers are also not applied in ordinary pattern matching.</p>
</li>
<li>
<p><code>u</code><br />
Respect the current locale in determining the presence of multibyte
characters in a pattern, provided the shell was compiled with
<code>MULTIBYTE_SUPPORT</code>. This overrides the <code>MULTIBYTE</code> option; the
default behaviour is taken from the option. Compare <code>U</code>. (Mnemonic:
typically multibyte characters are from Unicode in the UTF-8
encoding, although any extension of ASCII supported by the system
library may be used.)</p>
</li>
<li>
<p><code>U</code><br />
All characters are considered to be a single byte long. The opposite
of <code>u</code>. This overrides the <code>MULTIBYTE</code> option.</p>
</li>
</ul>
<p>For example, the test string <code>fooxx</code> can be matched by the pattern
<code>(#i``)FOOXX</code>, but not by <code>(#l``)FOOXX</code>, <code>(#i``)FOO``(#I``)XX</code> or
<code>((#i``)FOOX``)X</code>. The string <code>(#ia2``)readme</code> specifies
case-insensitive matching of <code>readme</code> with up to two errors.</p>
<p>When using the ksh syntax for grouping both <code>KSH_GLOB</code> and
<code>EXTENDED_GLOB</code> must be set and the left parenthesis should be preceded
by <code>@</code>. Note also that the flags do not affect letters inside <code>[</code>...<code>]</code>
groups, in other words <code>(#i``)[a-z]</code> still matches only lowercase
letters. Finally, note that when examining whole paths
case-insensitively every directory must be searched for all files which
match, so that a pattern of the form <code>(#i``)/foo/bar/...</code> is potentially
slow.</p>
<hr />
<p><span id="Approximate-Matching"></span></p>
<h3 id="1485-approximate-matching"><a class="header" href="#1485-approximate-matching">14.8.5 Approximate Matching</a></h3>
<p>When matching approximately, the shell keeps a count of the errors
found, which cannot exceed the number specified in the <code>(#a``num``)</code>
flags. Four types of error are recognised:</p>
<ul>
<li>
<p>1.<br />
Different characters, as in <code>fooxbar</code> and <code>fooybar</code>.</p>
</li>
<li>
<p>2.<br />
Transposition of characters, as in <code>banana</code> and <code>abnana</code>.</p>
</li>
<li>
<p>3.<br />
A character missing in the target string, as with the pattern <code>road</code>
and target string <code>rod</code>.</p>
</li>
<li>
<p>4.<br />
An extra character appearing in the target string, as with <code>stove</code>
and <code>strove</code>.</p>
</li>
</ul>
<p>Thus, the pattern <code>(#a3``)abcd</code> matches <code>dcba</code>, with the errors
occurring by using the first rule twice and the second once, grouping
the string as <code>[d][cb][a]</code> and <code>[a][bc][d]</code>.</p>
<p>Non-literal parts of the pattern must match exactly, including
characters in character ranges: hence <code>(#a1``)???</code> matches strings of
length four, by applying rule 4 to an empty part of the pattern, but not
strings of length two, since all the <code>?</code> must match. Other characters
which must match exactly are initial dots in filenames (unless the
<code>GLOB_DOTS</code> option is set), and all slashes in filenames, so that <code>a/bc</code>
is two errors from <code>ab/c</code> (the slash cannot be transposed with another
character). Similarly, errors are counted separately for non-contiguous
strings in the pattern, so that <code>(ab|cd``)ef</code> is two errors from <code>aebf</code>.</p>
<p>When using exclusion via the <code>~</code> operator, approximate matching is
treated entirely separately for the excluded part and must be activated
separately. Thus, <code>(#a1``)README~READ_ME</code> matches <code>READ.ME</code> but not
<code>READ_ME</code>, as the trailing <code>READ_ME</code> is matched without approximation.
However, <code>(#a1``)README~(#a1``)READ_ME</code> does not match any pattern of
the form <code>READ``?``ME</code> as all such forms are now excluded.</p>
<p>Apart from exclusions, there is only one overall error count; however,
the maximum errors allowed may be altered locally, and this can be
delimited by grouping. For example, <code>(#a1``)cat``((#a0``)dog``)fox</code>
allows one error in total, which may not occur in the <code>dog</code> section, and
the pattern <code>(#a1``)cat``(#a0``)dog``(#a1``)fox</code> is equivalent. Note
that the point at which an error is first found is the crucial one for
establishing whether to use approximation; for example,
<code>(#a1)abc(#a0)xyz</code> will not match <code>abcdxyz</code>, because the error occurs at
the ‘<code>x</code>’, where approximation is turned off.</p>
<p>Entire path segments may be matched approximately, so that
‘<code>(#a1)/foo/d/is/available/at/the/bar</code>’ allows one error in any path
segment. This is much less efficient than without the <code>(#a1)</code>, however,
since every directory in the path must be scanned for a possible
approximate match. It is best to place the <code>(#a1)</code> after any path
segments which are known to be correct.</p>
<hr />
<p><span id="Recursive-Globbing"></span></p>
<h3 id="1486-recursive-globbing"><a class="header" href="#1486-recursive-globbing">14.8.6 Recursive Globbing</a></h3>
<p>A pathname component of the form ‘<code>(``foo``/)#</code>’ matches a path
consisting of zero or more directories matching the pattern <code>foo</code>.</p>
<p>As a shorthand, ‘<code>**/</code>’ is equivalent to ‘<code>(*/)#</code>’; note that this
therefore matches files in the current directory as well as
subdirectories. Thus:</p>
<div class="example">
<pre><code class="language-example">ls -ld -- (*/)#bar
</code></pre>
</div>
<p>or</p>
<div class="example">
<pre><code class="language-example">ls -ld -- **/bar
</code></pre>
</div>
<p>does a recursive directory search for files named ‘<code>bar</code>’ (potentially
including the file ‘<code>bar</code>’ in the current directory). This form does not
follow symbolic links; the alternative form ‘<code>***/</code>’ does, but is
otherwise identical. Neither of these can be combined with other forms
of globbing within the same path segment; in that case, the ‘<code>*</code>’
operators revert to their usual effect.</p>
<p>Even shorter forms are available when the option <code>GLOB_STAR_SHORT</code> is
set. In that case if no <code>/</code> immediately follows a <code>**</code> or <code>***</code> they are
treated as if both a <code>/</code> plus a further <code>*</code> are present. Hence:</p>
<div class="example">
<pre><code class="language-example">setopt GLOBSTARSHORT
ls -ld -- **.c
</code></pre>
</div>
<p>is equivalent to</p>
<div class="example">
<pre><code class="language-example">ls -ld -- **/*.c
</code></pre>
</div>
<hr />
<p><span id="Glob-Qualifiers"></span></p>
<h3 id="1487-glob-qualifiers"><a class="header" href="#1487-glob-qualifiers">14.8.7 Glob Qualifiers</a></h3>
<p><span id="index-globbing_002c-qualifiers"></span>
<span id="index-qualifiers_002c-globbing"></span></p>
<p>Patterns used for filename generation may end in a list of qualifiers
enclosed in parentheses. The qualifiers specify which filenames that
otherwise match the given pattern will be inserted in the argument list.</p>
<p><span id="index-BARE_005fGLOB_005fQUAL_002c-use-of"></span></p>
<p>If the option <code>BARE_GLOB_QUAL</code> is set, then a trailing set of
parentheses containing no ‘<code>|</code>’ or ‘<code>(</code>’ characters (or ‘<code>~</code>’ if it is
special) is taken as a set of glob qualifiers. A glob subexpression that
would normally be taken as glob qualifiers, for example ‘<code>(^x)</code>’, can be
forced to be treated as part of the glob pattern by doubling the
parentheses, in this case producing ‘<code>((^x))</code>’.</p>
<p>If the option <code>EXTENDED_GLOB</code> is set, a different syntax for glob
qualifiers is available, namely ‘<code>(#q``x``)</code>’ where <code>x</code> is any of the
same glob qualifiers used in the other format. The qualifiers must still
appear at the end of the pattern. However, with this syntax multiple
glob qualifiers may be chained together. They are treated as a logical
AND of the individual sets of flags. Also, as the syntax is unambiguous,
the expression will be treated as glob qualifiers just as long any
parentheses contained within it are balanced; appearance of ‘<code>|</code>’, ‘<code>(</code>’
or ‘<code>~</code>’ does not negate the effect. Note that qualifiers will be
recognised in this form even if a bare glob qualifier exists at the end
of files if both options are set; however, mixed syntax should probably
be avoided for the sake of clarity. Note that within conditions using
the ‘<code>[[</code>’ form the presence of a parenthesised expression <code>(#q``...``)</code>
at the end of a string indicates that globbing should be performed; the
expression may include glob qualifiers, but it is also valid if it is
simply <code>(#q)</code>. This does not apply to the right hand side of pattern
match operators as the syntax already has special significance.</p>
<p>A qualifier may be any one of the following:</p>
<ul>
<li>
<p><code>/</code><br />
directories</p>
</li>
<li>
<p><code>F</code><br />
‘full’ (i.e. non-empty) directories. Note that the opposite sense
<code>(^F``)</code> expands to empty directories and all non-directories. Use
<code>(/^F``)</code> for empty directories.</p>
</li>
<li>
<p><code>.</code><br />
plain files</p>
</li>
<li>
<p><code>@</code><br />
symbolic links</p>
</li>
<li>
<p><code>=</code><br />
sockets</p>
</li>
<li>
<p><code>p</code><br />
named pipes (FIFOs)</p>
</li>
<li>
<p><code>*</code><br />
<code>%</code><br />
device files (character or block special)</p>
</li>
<li>
<p><code>%b</code><br />
block special files</p>
</li>
<li>
<p><code>%c</code><br />
character special files</p>
</li>
<li>
<p><code>r</code><br />
owner-readable files (0400)</p>
</li>
<li>
<p><code>w</code><br />
<code>x</code><br />
<code>A</code><br />
group-readable files (0040)</p>
</li>
<li>
<p><code>I</code><br />
<code>E</code><br />
<code>R</code><br />
world-readable files (0004)</p>
</li>
<li>
<p><code>W</code><br />
<code>X</code><br />
<code>s</code><br />
setuid files (04000)</p>
</li>
<li>
<p><code>S</code><br />
setgid files (02000)</p>
</li>
<li>
<p><code>t</code><br />
files with the sticky bit (01000)</p>
</li>
<li>
<p><code>f``spec</code><br />
files with access rights matching <code>spec</code>. This <code>spec</code> may be a octal
number optionally preceded by a ‘<code>=</code>’, a ‘<code>+</code>’, or a ‘<code>-</code>’. If none
of these characters is given, the behavior is the same as for ‘<code>=</code>’.
The octal number describes the mode bits to be expected, if combined
with a ‘<code>=</code>’, the value given must match the file-modes exactly,
with a ‘<code>+</code>’, at least the bits in the given number must be set in
the file-modes, and with a ‘<code>-</code>’, the bits in the number must not be
set. Giving a ‘<code>?</code>’ instead of a octal digit anywhere in the number
ensures that the corresponding bits in the file-modes are not
checked, this is only useful in combination with ‘<code>=</code>’.</p>
<p>If the qualifier ‘<code>f</code>’ is followed by any other character anything
up to the next matching character (‘<code>[</code>’, ‘<code>{</code>’, and ‘<code>&lt;</code>’ match
‘<code>]</code>’, ‘<code>}</code>’, and ‘<code>&gt;</code>’ respectively, any other character matches
itself) is taken as a list of comma-separated <code>sub-spec</code>s. Each
<code>sub-spec</code> may be either an octal number as described above or a
list of any of the characters ‘<code>u</code>’, ‘<code>g</code>’, ‘<code>o</code>’, and ‘<code>a</code>’,
followed by a ‘<code>=</code>’, a ‘<code>+</code>’, or a ‘<code>-</code>’, followed by a list of any
of the characters ‘<code>r</code>’, ‘<code>w</code>’, ‘<code>x</code>’, ‘<code>s</code>’, and ‘<code>t</code>’, or an octal
digit. The first list of characters specify which access rights are
to be checked. If a ‘<code>u</code>’ is given, those for the owner of the file
are used, if a ‘<code>g</code>’ is given, those of the group are checked, a
‘<code>o</code>’ means to test those of other users, and the ‘<code>a</code>’ says to
test all three groups. The ‘<code>=</code>’, ‘<code>+</code>’, and ‘<code>-</code>’ again says how
the modes are to be checked and have the same meaning as described
for the first form above. The second list of characters finally says
which access rights are to be expected: ‘<code>r</code>’ for read access, ‘<code>w</code>’
for write access, ‘<code>x</code>’ for the right to execute the file (or to
search a directory), ‘<code>s</code>’ for the setuid and setgid bits, and ‘<code>t</code>’
for the sticky bit.</p>
<p>Thus, ‘<code>*(f70?)</code>’ gives the files for which the owner has read,
write, and execute permission, and for which other group members
have no rights, independent of the permissions for other users. The
pattern ‘<code>*(f-100)</code>’ gives all files for which the owner does not
have execute permission, and ‘<code>*(f:gu+w,o-rx:)</code>’ gives the files for
which the owner and the other members of the group have at least
write permission, and for which other users don’t have read or
execute permission.</p>
</li>
<li>
<p><code>e``string</code><br />
<code>+``cmd</code><br />
The <code>string</code> will be executed as shell code. The filename will be
included in the list if and only if the code returns a zero status
(usually the status of the last command).</p>
<p>In the first form, the first character after the ‘<code>e</code>’ will be used
as a separator and anything up to the next matching separator will
be taken as the <code>string</code>; ‘<code>[</code>’, ‘<code>{</code>’, and ‘<code>&lt;</code>’ match ‘<code>]</code>’,
‘<code>}</code>’, and ‘<code>&gt;</code>’, respectively, while any other character
matches itself. Note that expansions must be quoted in the <code>string</code>
to prevent them from being expanded before globbing is done.
<code>string</code> is then executed as shell code. The string <code>globqual</code> is
appended to the array <code>zsh_eval_context</code> the duration of execution.</p>
<p><span id="index-REPLY_002c-use-of-1"></span>
<span id="index-reply_002c-use-of"></span></p>
<p>During the execution of <code>string</code> the filename currently being tested
is available in the parameter <code>REPLY</code>; the parameter may be altered
to a string to be inserted into the list instead of the original
filename. In addition, the parameter <code>reply</code> may be set to an array
or a string, which overrides the value of <code>REPLY</code>. If set to an
array, the latter is inserted into the command line word by word.</p>
<p>For example, suppose a directory contains a single file ‘<code>lonely</code>’.
Then the expression ‘<code>*(e:’reply=(${REPLY}{1,2})’:)</code>’ will cause the
words ‘<code>lonely1</code>’ and ‘<code>lonely2</code>’ to be inserted into the command
line. Note the quoting of <code>string</code>.</p>
<p>The form <code>+``cmd</code> has the same effect, but no delimiters appear
around <code>cmd</code>. Instead, <code>cmd</code> is taken as the longest sequence of
characters following the <code>+</code> that are alphanumeric or underscore.
Typically <code>cmd</code> will be the name of a shell function that contains
the appropriate test. For example,</p>
<div class="example">
<pre><code class="language-example">nt() { [[ $REPLY -nt $NTREF ]] }
NTREF=reffile
ls -ld -- *(+nt)
</code></pre>
</div>
<p>lists all files in the directory that have been modified more
recently than <code>reffile</code>.</p>
</li>
<li>
<p><code>d``dev</code><br />
files on the device <code>dev</code></p>
</li>
<li>
<p><code>l</code>[<code>-</code>|<code>+</code>]<code>ct</code><br />
files having a link count less than <code>ct</code> (<code>-</code>), greater than <code>ct</code>
(<code>+</code>), or equal to <code>ct</code></p>
</li>
<li>
<p><code>U</code><br />
files owned by the effective user ID</p>
</li>
<li>
<p><code>G</code><br />
files owned by the effective group ID</p>
</li>
<li>
<p><code>u``id</code><br />
files owned by user ID <code>id</code> if that is a number. Otherwise, <code>id</code>
specifies a user name: the character after the ‘<code>u</code>’ will be taken
as a separator and the string between it and the next matching
separator will be taken as a user name. The starting separators
‘<code>[</code>’, ‘<code>{</code>’, and ‘<code>&lt;</code>’ match the final separators ‘<code>]</code>’, ‘<code>}</code>’,
and ‘<code>&gt;</code>’, respectively; any other character matches itself. The
selected files are those owned by this user. For example, ‘<code>u:foo:</code>’
or ‘<code>u[foo]</code>’ selects files owned by user ‘<code>foo</code>’.</p>
</li>
<li>
<p><code>g``id</code><br />
like <code>u``id</code> but with group IDs or names</p>
</li>
<li>
<p><code>a</code>[<code>Mwhms</code>][<code>-</code>|<code>+</code>]<code>n</code><br />
files accessed exactly <code>n</code> days ago. Files accessed within the last
<code>n</code> days are selected using a negative value for <code>n</code> (<code>-``n</code>). Files
accessed more than <code>n</code> days ago are selected by a positive <code>n</code> value
(<code>+``n</code>). Optional unit specifiers ‘<code>M</code>’, ‘<code>w</code>’, ‘<code>h</code>’, ‘<code>m</code>’ or
‘<code>s</code>’ (e.g. ‘<code>ah5</code>’) cause the check to be performed with months
(of 30 days), weeks, hours, minutes or seconds instead of days,
respectively. An explicit ‘<code>d</code>’ for days is also allowed.</p>
<p>Any fractional part of the difference between the access time and
the current part in the appropriate units is ignored in the
comparison. For instance, ‘<code>echo *(ah-5)</code>’ would echo files accessed
within the last five hours, while ‘<code>echo *(ah+5)</code>’ would echo files
accessed at least six hours ago, as times strictly between five and
six hours are treated as five hours.</p>
</li>
<li>
<p><code>m</code>[<code>Mwhms</code>][<code>-</code>|<code>+</code>]<code>n</code><br />
like the file access qualifier, except that it uses the file
modification time.</p>
</li>
<li>
<p><code>c</code>[<code>Mwhms</code>][<code>-</code>|<code>+</code>]<code>n</code><br />
like the file access qualifier, except that it uses the file inode
change time.</p>
</li>
<li>
<p><code>L</code>[<code>+</code>|<code>-</code>]<code>n</code><br />
files less than <code>n</code> bytes (<code>-</code>), more than <code>n</code> bytes (<code>+</code>), or
exactly <code>n</code> bytes in length.</p>
<p>If this flag is directly followed by a <em>size specifier</em> ‘<code>k</code>’
(‘<code>K</code>’), ‘<code>m</code>’ (‘<code>M</code>’), or ‘<code>p</code>’ (‘<code>P</code>’) (e.g. ‘<code>Lk-50</code>’) the
check is performed with kilobytes, megabytes, or blocks (of 512
bytes) instead. (On some systems additional specifiers are available
for gigabytes, ‘<code>g</code>’ or ‘<code>G</code>’, and terabytes, ‘<code>t</code>’ or ‘<code>T</code>’.) If a
size specifier is used a file is regarded as &quot;exactly&quot; the size if
the file size rounded up to the next unit is equal to the test size.
Hence ‘<code>*(Lm1)</code>’ matches files from 1 byte up to 1 Megabyte
inclusive. Note also that the set of files &quot;less than&quot; the test size
only includes files that would not match the equality test; hence
‘<code>*(Lm-1)</code>’ only matches files of zero size.</p>
</li>
<li>
<p><code>^</code><br />
negates all qualifiers following it</p>
</li>
<li>
<p><code>-</code><br />
toggles between making the qualifiers work on symbolic links (the
default) and the files they point to</p>
</li>
<li>
<p><code>M</code><br />
sets the <code>MARK_DIRS</code> option for the current pattern
<span id="index-MARK_005fDIRS_002c-setting-in-pattern"></span></p>
</li>
<li>
<p><code>T</code><br />
appends a trailing qualifier mark to the filenames, analogous to the
<code>LIST_TYPES</code> option, for the current pattern (overrides <code>M</code>)</p>
</li>
<li>
<p><code>N</code><br />
sets the <code>NULL_GLOB</code> option for the current pattern
<span id="index-NULL_005fGLOB_002c-setting-in-pattern"></span></p>
</li>
<li>
<p><code>D</code><br />
sets the <code>GLOB_DOTS</code> option for the current pattern
<span id="index-GLOB_005fDOTS_002c-setting-in-pattern"></span></p>
</li>
<li>
<p><code>n</code><br />
sets the <code>NUMERIC_GLOB_SORT</code> option for the current pattern
<span id="index-NUMERIC_005fGLOB_005fSORT_002c-setting-in-pattern"></span></p>
</li>
<li>
<p><code>Y``n</code><br />
enables short-circuit mode: the pattern will expand to at most <code>n</code>
filenames. If more than <code>n</code> matches exist, only the first <code>n</code>
matches in directory traversal order will be considered.</p>
<p>Implies <code>oN</code> when no <code>o``c</code> qualifier is used.</p>
</li>
<li>
<p><code>o``c</code><br />
specifies how the names of the files should be sorted. If <code>c</code> is <code>n</code>
they are sorted by name; if it is <code>L</code> they are sorted depending on
the size (length) of the files; if <code>l</code> they are sorted by the number
of links; if <code>a</code>, <code>m</code>, or <code>c</code> they are sorted by the time of the
last access, modification, or inode change respectively; if <code>d</code>,
files in subdirectories appear before those in the current directory
at each level of the search — this is best combined with other
criteria, for example ‘<code>odon</code>’ to sort on names for files within the
same directory; if <code>N</code>, no sorting is performed. Note that <code>a</code>, <code>m</code>,
and <code>c</code> compare the age against the current time, hence the first
name in the list is the youngest file. Also note that the modifiers
<code>^</code> and <code>-</code> are used, so ‘<code>*(^-oL)</code>’ gives a list of all files
sorted by file size in descending order, following any symbolic
links. Unless <code>oN</code> is used, multiple order specifiers may occur to
resolve ties.</p>
<p>The default sorting is <code>n</code> (by name) unless the <code>Y</code> glob qualifier
is used, in which case it is <code>N</code> (unsorted).</p>
<p><code>oe</code> and <code>o+</code> are special cases; they are each followed by shell
code, delimited as for the <code>e</code> glob qualifier and the <code>+</code> glob
qualifier respectively (see above). The code is executed for each
matched file with the parameter <code>REPLY</code> set to the name of the file
on entry and <code>globsort</code> appended to <code>zsh_eval_context</code>. The code
should modify the parameter <code>REPLY</code> in some fashion. On return, the
value of the parameter is used instead of the file name as the
string on which to sort. Unlike other sort operators, <code>oe</code> and <code>o+</code>
may be repeated, but note that the maximum number of sort operators
of any kind that may appear in any glob expression is 12.</p>
</li>
<li>
<p><code>O``c</code><br />
like ‘<code>o</code>’, but sorts in descending order; i.e. ‘<code>*(^oc)</code>’ is the
same as ‘<code>*(Oc)</code>’ and ‘<code>*(^Oc)</code>’ is the same as ‘<code>*(oc)</code>’; ‘<code>Od</code>’
puts files in the current directory before those in subdirectories
at each level of the search.</p>
</li>
<li>
<p><code>[``beg</code>[<code>,``end</code>]<code>]</code><br />
specifies which of the matched filenames should be included in the
returned list. The syntax is the same as for array subscripts. <code>beg</code>
and the optional <code>end</code> may be mathematical expressions. As in
parameter subscripting they may be negative to make them count from
the last match backward. E.g.: ‘<code>*(-OL[1,3])</code>’ gives a list of the
names of the three largest files.</p>
</li>
<li>
<p><code>P``string</code><br />
The <code>string</code> will be prepended to each glob match as a separate
word. <code>string</code> is delimited in the same way as arguments to the <code>e</code>
glob qualifier described above. The qualifier can be repeated; the
words are prepended separately so that the resulting command line
contains the words in the same order they were given in the list of
glob qualifiers.</p>
<p>A typical use for this is to prepend an option before all
occurrences of a file name; for example, the pattern ‘<code>*(P:-f:)</code>’
produces the command line arguments ‘<code>-f</code> <code>file1</code> <code>-f</code> <code>file2</code> ...’</p>
<p>If the modifier <code>^</code> is active, then <code>string</code> will be appended
instead of prepended. Prepending and appending is done independently
so both can be used on the same glob expression; for example by
writing ‘<code>*(P:foo:^P:bar:^P:baz:)</code>’ which produces the command line
arguments ‘<code>foo</code> <code>baz</code> <code>file1</code> <code>bar</code> ...’</p>
</li>
</ul>
<p>More than one of these lists can be combined, separated by commas. The
whole list matches if at least one of the sublists matches (they are
‘or’ed, the qualifiers in the sublists are ‘and’ed). Some
qualifiers, however, affect all matches generated, independent of the
sublist in which they are given. These are the qualifiers ‘<code>M</code>’, ‘<code>T</code>’,
‘<code>N</code>’, ‘<code>D</code>’, ‘<code>n</code>’, ‘<code>o</code>’, ‘<code>O</code>’ and the subscripts given in brackets
(‘<code>[``...``]</code>’).</p>
<p>If a ‘<code>:</code>’ appears in a qualifier list, the remainder of the expression
in parenthesis is interpreted as a modifier (see <a href="Expansion.html#Modifiers">Modifiers</a>
in <a href="Expansion.html#History-Expansion">History Expansion</a>). Each modifier must be
introduced by a separate ‘<code>:</code>’. Note also that the result after
modification does not have to be an existing file. The name of any
existing file can be followed by a modifier of the form ‘<code>(:``...``)</code>’
even if no actual filename generation is performed, although note that
the presence of the parentheses causes the entire expression to be
subjected to any global pattern matching options such as <code>NULL_GLOB</code>.
Thus:</p>
<div class="example">
<pre><code class="language-example">ls -ld -- *(-/)
</code></pre>
</div>
<p>lists all directories and symbolic links that point to directories, and</p>
<div class="example">
<pre><code class="language-example">ls -ld -- *(-@)
</code></pre>
</div>
<p>lists all broken symbolic links, and</p>
<div class="example">
<pre><code class="language-example">ls -ld -- *(%W)
</code></pre>
</div>
<div class="example">
<pre><code class="language-example">ls -ld -- *(W,X)
</code></pre>
</div>
<p>lists all files in the current directory that are</p>
<div class="example">
<pre><code class="language-example">print -rC1 /tmp/foo*(u0^@:t)
</code></pre>
</div>
<p>outputs the basename of all root-owned files beginning with the string
‘<code>foo</code>’ in <code>/tmp</code>, ignoring symlinks, and</p>
<div class="example">
<pre><code class="language-example">ls -ld -- *.*~(lex|parse).[ch](^D^l1)
</code></pre>
</div>
<p>lists all files having a link count of one whose names contain a dot
(but not those starting with a dot, since <code>GLOB_DOTS</code> is explicitly
switched off) except for <code>lex.c</code>, <code>lex.h</code>, <code>parse.c</code> and <code>parse.h</code>.</p>
<div class="example">
<pre><code class="language-example">print -rC1 b*.pro(#q:s/pro/shmo/)(#q.:s/builtin/shmiltin/)
</code></pre>
</div>
<p>demonstrates how colon modifiers and other qualifiers may be chained
together. The ordinary qualifier ‘<code>.</code>’ is applied first, then the colon
modifiers in order from left to right. So if <code>EXTENDED_GLOB</code> is set and
the base pattern matches the regular file <code>builtin.pro</code>, the shell will
print ‘<code>shmiltin.shmo</code>’.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Parameters.html#15-parameters">15 Parameters</a>
<ul>
<li><a href="Parameters.html#151-description">15.1 Description</a></li>
<li><a href="Parameters.html#152-array-parameters">15.2 Array Parameters</a>
<ul>
<li><a href="Parameters.html#1521-array-subscripts">15.2.1 Array Subscripts</a></li>
<li><a href="Parameters.html#1522-array-element-assignment">15.2.2 Array Element Assignment</a></li>
<li><a href="Parameters.html#1523-subscript-flags">15.2.3 Subscript Flags</a></li>
<li><a href="Parameters.html#1524-subscript-parsing">15.2.4 Subscript Parsing</a></li>
</ul>
</li>
<li><a href="Parameters.html#153-positional-parameters">15.3 Positional Parameters</a></li>
<li><a href="Parameters.html#154-local-parameters">15.4 Local Parameters</a></li>
<li><a href="Parameters.html#155-parameters-set-by-the-shell">15.5 Parameters Set By The Shell</a></li>
<li><a href="Parameters.html#156-parameters-used-by-the-shell">15.6 Parameters Used By The Shell</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Parameters"></span> <span id="Parameters-1"></span></p>
<h1 id="15-parameters"><a class="header" href="#15-parameters">15 Parameters</a></h1>
<p><span id="index-parameters"></span> <span id="index-variables"></span></p>
<hr />
<p><span id="Description-5"></span></p>
<h2 id="151-description"><a class="header" href="#151-description">15.1 Description</a></h2>
<p>A parameter has a name, a value, and a number of attributes. A name may
be any sequence of alphanumeric characters and underscores, or the
single characters ‘<code>*</code>’, ‘<code>@</code>’, ‘<code>#</code>’, ‘<code>?</code>’, ‘<code>-</code>’, ‘<code>$</code>’, or ‘<code>!</code>’. A
parameter whose name begins with an alphanumeric or underscore is also
referred to as a <em>variable</em>.</p>
<p><span id="index-scalar"></span>
<span id="index-parameters_002c-scalar"></span>
<span id="index-parameters_002c-array"></span>
<span id="index-parameters_002c-associative-array"></span>
<span id="index-hash"></span></p>
<p>The attributes of a parameter determine the <em>type</em> of its value, often
referred to as the parameter type or variable type, and also control
other processing that may be applied to the value when it is referenced.
The value type may be a <em>scalar</em> (a string, an integer, or a floating
point number), an array (indexed numerically), or an <em>associative</em> array
(an unordered set of name-value pairs, indexed by name, also referred to
as a <em>hash</em>).</p>
<p><span id="index-export"></span> <span id="index-environment"></span>
<span id="index-environment-variables"></span>
<span id="index-variables_002c-environment"></span></p>
<p>Named scalar parameters may have the <em>exported</em>, <code>-x</code>, attribute, to
copy them into the process environment, which is then passed from the
shell to any new processes that it starts. Exported parameters are
called <em>environment variables</em>. The shell also <em>imports</em> environment
variables at startup time and automatically marks the corresponding
parameters as exported. Some environment variables are not imported for
reasons of security or because they would interfere with the correct
operation of other shell features.</p>
<p><span id="index-special-parameters"></span>
<span id="index-parameters_002c-special"></span></p>
<p>Parameters may also be <em>special</em>, that is, they have a predetermined
meaning to the shell. Special parameters cannot have their type changed
or their readonly attribute turned off, and if a special parameter is
unset, then later recreated, the special properties will be retained.</p>
<p>To declare the type of a parameter, or to assign a string or numeric
value to a scalar parameter, use the <code>typeset</code> builtin.
<span id="index-typeset_002c-use-of"></span></p>
<p>The value of a scalar parameter may also be assigned by writing:
<span id="index-assignment"></span></p>
<blockquote>
<p><code>name``=``value</code></p>
</blockquote>
<p>In scalar assignment, <code>value</code> is expanded as a single string, in which
the elements of arrays are joined together; filename expansion is not
performed unless the option <code>GLOB_ASSIGN</code> is set.</p>
<p>When the integer attribute, <code>-i</code>, or a floating point attribute, <code>-E</code> or
<code>-F</code>, is set for <code>name</code>, the <code>value</code> is subject to arithmetic
evaluation. Furthermore, by replacing ‘<code>=</code>’ with ‘<code>+=</code>’, a parameter can
be incremented or appended to. See <a href="Parameters.html#Array-Parameters">Array Parameters</a>
and <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a> for
additional forms of assignment.</p>
<p>Note that assignment may implicitly change the attributes of a
parameter. For example, assigning a number to a variable in arithmetic
evaluation may change its type to integer or float, and with
<code>GLOB_ASSIGN</code> assigning a pattern to a variable may change its type to
an array.</p>
<p>To reference the value of a parameter, write ‘<code>$``name</code>’ or
‘<code>${``name``}</code>’. See <a href="Expansion.html#Parameter-Expansion">Parameter
Expansion</a> for complete details.
That section also explains the effect of the difference between scalar
and array assignment on parameter expansion.</p>
<hr />
<p><span id="Array-Parameters"></span>
<span id="Array-Parameters-1"></span></p>
<h2 id="152-array-parameters"><a class="header" href="#152-array-parameters">15.2 Array Parameters</a></h2>
<p>To assign an array value, write one of:
<span id="index-set_002c-use-of"></span>
<span id="index-array-assignment"></span></p>
<blockquote>
<p><code>set -A</code> <code>name</code> <code>value</code> ...</p>
</blockquote>
<blockquote>
<p><code>name``=(``value</code> ...<code>)</code></p>
</blockquote>
<blockquote>
<p><code>name``=(``[``key``]=``value</code> ...<code>)</code></p>
</blockquote>
<p>If no parameter <code>name</code> exists, an ordinary array parameter is created.
If the parameter <code>name</code> exists and is a scalar, it is replaced by a new
array.</p>
<p>In the third form, <code>key</code> is an expression that will be evaluated in
arithmetic context (in its simplest form, an integer) that gives the
index of the element to be assigned with <code>value</code>. In this form any
elements not explicitly mentioned that come before the largest index to
which a value is assigned are assigned an empty string. The indices may
be in any order. Note that this syntax is strict: <code>[</code> and <code>]=</code> must not
be quoted, and <code>key</code> may not consist of the unquoted string <code>]=</code>, but is
otherwise treated as a simple string. The enhanced forms of subscript
expression that may be used when directly subscripting a variable name,
described in the section Array Subscripts below, are not available.</p>
<p>The syntaxes with and without the explicit key may be mixed. An implicit
<code>key</code> is deduced by incrementing the index from the previously assigned
element. Note that it is not treated as an error if latter assignments
in this form overwrite earlier assignments.</p>
<p>For example, assuming the option <code>KSH_ARRAYS</code> is not set, the following:</p>
<div class="example">
<pre><code class="language-example">array=(one [3]=three four)
</code></pre>
</div>
<p>causes the array variable <code>array</code> to contain four elements <code>one</code>, an
empty string, <code>three</code> and <code>four</code>, in that order.</p>
<p>In the forms where only <code>value</code> is specified, full command line
expansion is performed.</p>
<p>In the <code>[``key``]=``value</code> form, both <code>key</code> and <code>value</code> undergo all
forms of expansion allowed for single word shell expansions (this does
not include filename generation); these are as performed by the
parameter expansion flag <code>(e)</code> as described in <a href="Expansion.html#Parameter-Expansion">Parameter
Expansion</a>. Nested parentheses may
surround <code>value</code> and are included as part of the value, which is joined
into a plain string; this differs from ksh which allows the values
themselves to be arrays. A future version of zsh may support that. To
cause the brackets to be interpreted as a character class for filename
generation, and therefore to treat the resulting list of files as a set
of values, quote the equal sign using any form of quoting. Example:</p>
<blockquote>
<p><code>name``=(``[a-z]’=’*)</code></p>
</blockquote>
<p>To append to an array without changing the existing values, use one of
the following:</p>
<blockquote>
<p><code>name``+=(``value</code> ...<code>)</code></p>
</blockquote>
<blockquote>
<p><code>name``+=(``[``key``]=``value</code> ...<code>)</code></p>
</blockquote>
<p>In the second form <code>key</code> may specify an existing index as well as an
index off the end of the old array; any existing value is overwritten by
<code>value</code>. Also, it is possible to use <code>[``key``]+=``value</code> to append to
the existing value at that index.</p>
<p>Within the parentheses on the right hand side of either form of the
assignment, newlines and semicolons are treated the same as white space,
separating individual <code>value</code>s. Any consecutive sequence of such
characters has the same effect.</p>
<p>Ordinary array parameters may also be explicitly declared with:
<span id="index-typeset_002c-use-of-1"></span></p>
<blockquote>
<p><code>typeset -a</code> <code>name</code></p>
</blockquote>
<p>Associative arrays <em>must</em> be declared before assignment, by using:</p>
<blockquote>
<p><code>typeset -A</code> <code>name</code></p>
</blockquote>
<p>When <code>name</code> refers to an associative array, the list in an assignment is
interpreted as alternating keys and values:</p>
<blockquote>
<p><code>set -A</code> <code>name</code> <code>key</code> <code>value</code> ...</p>
</blockquote>
<blockquote>
<p><code>name``=(``key</code> <code>value</code> ...<code>)</code></p>
</blockquote>
<blockquote>
<p><code>name``=(``[``key``]=``value</code> ...<code>)</code></p>
</blockquote>
<p>Note that only one of the two syntaxes above may be used in any given
assignment; the forms may not be mixed. This is unlike the case of
numerically indexed arrays.</p>
<p>Every <code>key</code> must have a <code>value</code> in this case. Note that this assigns to
the entire array, deleting any elements that do not appear in the list.
The append syntax may also be used with an associative array:</p>
<blockquote>
<p><code>name``+=(``key</code> <code>value</code> ...<code>)</code></p>
</blockquote>
<blockquote>
<p><code>name``+=(``[``key``]=``value</code> ...<code>)</code></p>
</blockquote>
<p>This adds a new key/value pair if the key is not already present, and
replaces the value for the existing key if it is. In the second form it
is also possible to use <code>[``key``]+=``value</code> to append to the existing
value at that key. Expansion is performed identically to the
corresponding forms for normal arrays, as described above.</p>
<p>To create an empty array (including associative arrays), use one of:</p>
<blockquote>
<p><code>set -A</code> <code>name</code></p>
</blockquote>
<blockquote>
<p><code>name``=()</code></p>
</blockquote>
<hr />
<p><span id="Array-Subscripts"></span></p>
<h3 id="1521-array-subscripts"><a class="header" href="#1521-array-subscripts">15.2.1 Array Subscripts</a></h3>
<p><span id="index-subscripts"></span></p>
<p>Individual elements of an array may be selected using a subscript. A
subscript of the form ‘<code>[``exp``]</code>’ selects the single element <code>exp</code>,
where <code>exp</code> is an arithmetic expression which will be subject to
arithmetic expansion as if it were surrounded by ‘<code>$((</code>...<code>))</code>’. The
elements are numbered beginning with 1, unless the <code>KSH_ARRAYS</code> option
is set in which case they are numbered from zero.
<span id="index-KSH_005fARRAYS_002c-use-of"></span></p>
<p>Subscripts may be used inside braces used to delimit a parameter name,
thus ‘<code>${foo[2]}</code>’ is equivalent to ‘<code>$foo[2]</code>’. If the <code>KSH_ARRAYS</code>
option is set, the braced form is the only one that works, as bracketed
expressions otherwise are not treated as subscripts.</p>
<p>If the <code>KSH_ARRAYS</code> option is not set, then by default accesses to an
array element with a subscript that evaluates to zero return an empty
string, while an attempt to write such an element is treated as an
error. For backward compatibility the <code>KSH_ZERO_SUBSCRIPT</code> option can be
set to cause subscript values 0 and 1 to be equivalent; see the
description of the option in <a href="Options.html#Description-of-Options">Description of
Options</a>.</p>
<p>The same subscripting syntax is used for associative arrays, except that
no arithmetic expansion is applied to <code>exp</code>. However, the parsing rules
for arithmetic expressions still apply, which affects the way that
certain special characters must be protected from interpretation. See
<em>Subscript Parsing</em> below for details.</p>
<p>A subscript of the form ‘<code>[*]</code>’ or ‘<code>[@]</code>’ evaluates to all elements of
an array; there is no difference between the two except when they appear
within double quotes. ‘<code>&quot;$foo[*]&quot;</code>’ evaluates to ‘<code>&quot;$foo[1] $foo[2]
</code>...<code>&quot;</code>’, whereas ‘<code>&quot;$foo[@]&quot;</code>’ evaluates to ‘<code>&quot;$foo[1]&quot; &quot;$foo[2]&quot;
</code>...’. For associative arrays, ‘<code>[*]</code>’ or ‘<code>[@]</code>’ evaluate to all the
values, in no particular order. Note that this does not substitute the
keys; see the documentation for the ‘<code>k</code>’ flag under <a href="Expansion.html#Parameter-Expansion">Parameter
Expansion</a> for complete details.
When an array parameter is referenced as ‘<code>$``name</code>’ (with no subscript)
it evaluates to ‘<code>$``name``[*]</code>’, unless the <code>KSH_ARRAYS</code> option is set
in which case it evaluates to ‘<code>${``name``[0]}</code>’ (for an associative
array, this means the value of the key ‘<code>0</code>’, which may not exist even
if there are values for other keys).</p>
<p>A subscript of the form ‘<code>[``exp1``,``exp2``]</code>’ selects all elements in
the range <code>exp1</code> to <code>exp2</code>, inclusive. (Associative arrays are
unordered, and so do not support ranges.) If one of the subscripts
evaluates to a negative number, say <code>-``n</code>, then the <code>n</code>th element from
the end of the array is used. Thus ‘<code>$foo[-3]</code>’ is the third element
from the end of the array <code>foo</code>, and ‘<code>$foo[1,-1]</code>’ is the same as
‘<code>$foo[*]</code>’.</p>
<p>Subscripting may also be performed on non-array values, in which case
the subscripts specify a substring to be extracted. For example, if
<code>FOO</code> is set to ‘<code>foobar</code>’, then ‘<code>echo $FOO[2,5]</code>’ prints ‘<code>ooba</code>’.
Note that some forms of subscripting described below perform pattern
matching, and in that case the substring extends from the start of the
match of the first subscript to the end of the match of the second
subscript. For example,</p>
<div class="example">
<pre><code class="language-example">string=&quot;abcdefghijklm&quot;
print ${string[(r)d?,(r)h?]}
</code></pre>
</div>
<p>prints ‘<code>defghi</code>’. This is an obvious generalisation of the rule for
single-character matches. For a single subscript, only a single
character is referenced (not the range of characters covered by the
match).</p>
<p>Note that in substring operations the second subscript is handled
differently by the <code>r</code> and <code>R</code> subscript flags: the former takes the
shortest match as the length and the latter the longest match. Hence in
the former case a <code>*</code> at the end is redundant while in the latter case
it matches the whole remainder of the string. This does not affect the
result of the single subscript case as here the length of the match is
irrelevant.</p>
<hr />
<p><span id="Array-Element-Assignment"></span></p>
<h3 id="1522-array-element-assignment"><a class="header" href="#1522-array-element-assignment">15.2.2 Array Element Assignment</a></h3>
<p>A subscript may be used on the left side of an assignment like so:</p>
<blockquote>
<p><code>name``[``exp``]=``value</code></p>
</blockquote>
<p>In this form of assignment the element or range specified by <code>exp</code> is
replaced by the expression on the right side. An array (but not an
associative array) may be created by assignment to a range or element.
Arrays do not nest, so assigning a parenthesized list of values to an
element or range changes the number of elements in the array, shifting
the other elements to accommodate the new values. (This is not supported
for associative arrays.)</p>
<p>This syntax also works as an argument to the <code>typeset</code> command:</p>
<blockquote>
<p><code>typeset</code> <code>&quot;``name``[``exp``]&quot;=``value</code></p>
</blockquote>
<p>The <code>value</code> may <em>not</em> be a parenthesized list in this case; only
single-element assignments may be made with <code>typeset</code>. Note that quotes
are necessary in this case to prevent the brackets from being
interpreted as filename generation operators. The <code>noglob</code> precommand
modifier could be used instead.</p>
<p>To delete an element of an ordinary array, assign ‘<code>()</code>’ to that
element. To delete an element of an associative array, use the <code>unset</code>
command:</p>
<blockquote>
<p><code>unset</code> <code>&quot;``name``[``exp``]&quot;</code></p>
</blockquote>
<hr />
<p><span id="Subscript-Flags"></span></p>
<h3 id="1523-subscript-flags"><a class="header" href="#1523-subscript-flags">15.2.3 Subscript Flags</a></h3>
<p><span id="index-subscript-flags"></span></p>
<p>If the opening bracket, or the comma in a range, in any subscript
expression is directly followed by an opening parenthesis, the string up
to the matching closing one is considered to be a list of flags, as in
‘<code>name``[(``flags``)``exp``]</code>’.</p>
<p>The flags <code>s</code>, <code>n</code> and <code>b</code> take an argument; the delimiter is shown
below as ‘<code>:</code>’, but any character, or the matching pairs ‘<code>(</code>...<code>)</code>’,
‘<code>{</code>...<code>}</code>’, ‘<code>[</code>...<code>]</code>’, or ‘<code>&lt;</code>...<code>&gt;</code>’, may be used, but note that
‘<code>&lt;</code>...<code>&gt;</code>’ can only be used if the subscript is inside a double
quoted expression or a parameter substitution enclosed in braces as
otherwise the expression is interpreted as a redirection.</p>
<p>The flags currently understood are:</p>
<ul>
<li>
<p><code>w</code><br />
If the parameter subscripted is a scalar then this flag makes
subscripting work on words instead of characters. The default word
separator is whitespace. When combined with the <code>i</code> or <code>I</code> flag, the
effect is to produce the index of the first character of the
first/last word which matches the given pattern; note that a failed
match in this case always yields 0.</p>
</li>
<li>
<p><code>s:``string``:</code><br />
This gives the <code>string</code> that separates words (for use with the <code>w</code>
flag). The delimiter character <code>:</code> is arbitrary; see above.</p>
</li>
<li>
<p><code>p</code><br />
Recognize the same escape sequences as the <code>print</code> builtin in the
string argument of a subsequent ‘<code>s</code>’ flag.</p>
</li>
<li>
<p><code>f</code><br />
If the parameter subscripted is a scalar then this flag makes
subscripting work on lines instead of characters, i.e. with elements
separated by newlines. This is a shorthand for ‘<code>pws:\n:</code>’.</p>
</li>
<li>
<p><code>r</code><br />
Reverse subscripting: if this flag is given, the <code>exp</code> is taken as a
pattern and the result is the first matching array element,
substring or word (if the parameter is an array, if it is a scalar,
or if it is a scalar and the ‘<code>w</code>’ flag is given, respectively). The
subscript used is the number of the matching element, so that pairs
of subscripts such as ‘<code>$foo[(r)??,3]</code>’ and ‘<code>$foo[(r)??,(r)f*]</code>’
are possible if the parameter is not an associative array. If the
parameter is an associative array, only the value part of each pair
is compared to the pattern, and the result is that value.</p>
<p>If a search through an ordinary array failed, the search sets the
subscript to one past the end of the array, and hence
<code>${array[(r)``pattern``]}</code> will substitute the empty string. Thus
the success of a search can be tested by using the <code>(i)</code> flag, for
example (assuming the option <code>KSH_ARRAYS</code> is not in effect):</p>
<div class="example">
<pre><code class="language-example">[[ ${array[(i)pattern]} -le ${#array} ]]
</code></pre>
</div>
<p>If <code>KSH_ARRAYS</code> is in effect, the <code>-le</code> should be replaced by <code>-lt</code>.</p>
</li>
<li>
<p><code>R</code><br />
Like ‘<code>r</code>’, but gives the last match. For associative arrays, gives
all possible matches. May be used for assigning to ordinary array
elements, but not for assigning to associative arrays. On failure,
for normal arrays this has the effect of returning the element
corresponding to subscript 0; this is empty unless one of the
options <code>KSH_ARRAYS</code> or <code>KSH_ZERO_SUBSCRIPT</code> is in effect.</p>
<p>Note that in subscripts with both ‘<code>r</code>’ and ‘<code>R</code>’ pattern characters
are active even if they were substituted for a parameter (regardless
of the setting of <code>GLOB_SUBST</code> which controls this feature in normal
pattern matching). The flag ‘<code>e</code>’ can be added to inhibit pattern
matching. As this flag does not inhibit other forms of substitution,
care is still required; using a parameter to hold the key has the
desired effect:</p>
<div class="example">
<pre><code class="language-example">key2='original key'
print ${array[(Re)$key2]}
</code></pre>
</div>
</li>
<li>
<p><code>i</code><br />
Like ‘<code>r</code>’, but gives the index of the match instead; this may not
be combined with a second argument. On the left side of an
assignment, behaves like ‘<code>r</code>’. For associative arrays, the key part
of each pair is compared to the pattern, and the first matching key
found is the result. On failure substitutes the length of the array
plus one, as discussed under the description of ‘<code>r</code>’, or the empty
string for an associative array.</p>
</li>
<li>
<p><code>I</code><br />
Like ‘<code>i</code>’, but gives the index of the last match, or all possible
matching keys in an associative array. On failure substitutes 0, or
the empty string for an associative array. This flag is best when
testing for values or keys that do not exist.</p>
</li>
<li>
<p><code>k</code><br />
If used in a subscript on an associative array, this flag causes the
keys to be interpreted as patterns, and returns the value for the
first key found where <code>exp</code> is matched by the key. Note this could
be any such key as no ordering of associative arrays is defined.
This flag does not work on the left side of an assignment to an
associative array element. If used on another type of parameter,
this behaves like ‘<code>r</code>’.</p>
</li>
<li>
<p><code>K</code><br />
On an associative array this is like ‘<code>k</code>’ but returns all values
where <code>exp</code> is matched by the keys. On other types of parameters
this has the same effect as ‘<code>R</code>’.</p>
</li>
<li>
<p><code>n:``expr``:</code><br />
If combined with ‘<code>r</code>’, ‘<code>R</code>’, ‘<code>i</code>’ or ‘<code>I</code>’, makes them give the
<code>n</code>th or <code>n</code>th last match (if <code>expr</code> evaluates to <code>n</code>). This flag is
ignored when the array is associative. The delimiter character <code>:</code>
is arbitrary; see above.</p>
</li>
<li>
<p><code>b:``expr``:</code><br />
If combined with ‘<code>r</code>’, ‘<code>R</code>’, ‘<code>i</code>’ or ‘<code>I</code>’, makes them begin at
the <code>n</code>th or <code>n</code>th last element, word, or character (if <code>expr</code>
evaluates to <code>n</code>). This flag is ignored when the array is
associative. The delimiter character <code>:</code> is arbitrary; see above.</p>
</li>
<li>
<p><code>e</code><br />
This flag causes any pattern matching that would be performed on the
subscript to use plain string matching instead. Hence
‘<code>${array[(re)*]}</code>’ matches only the array element whose value is
<code>*</code>. Note that other forms of substitution such as parameter
substitution are not inhibited.</p>
<p>This flag can also be used to force <code>*</code> or <code>@</code> to be interpreted as
a single key rather than as a reference to all values. It may be
used for either purpose on the left side of an assignment.</p>
</li>
</ul>
<p>See <em>Parameter Expansion Flags</em> (<a href="Expansion.html#Parameter-Expansion">Parameter
Expansion</a>) for additional ways to
manipulate the results of array subscripting.</p>
<hr />
<p><span id="Subscript-Parsing"></span></p>
<h3 id="1524-subscript-parsing"><a class="header" href="#1524-subscript-parsing">15.2.4 Subscript Parsing</a></h3>
<p>This discussion applies mainly to associative array key strings and to
patterns used for reverse subscripting (the ‘<code>r</code>’, ‘<code>R</code>’, ‘<code>i</code>’, etc.
flags), but it may also affect parameter substitutions that appear as
part of an arithmetic expression in an ordinary subscript.</p>
<p>To avoid subscript parsing limitations in assignments to associative
array elements, use the append syntax:</p>
<div class="example">
<pre><code class="language-example">aa+=('key with &quot;*strange*&quot; characters' 'value string')
</code></pre>
</div>
<p>The basic rule to remember when writing a subscript expression is that
all text between the opening ‘<code>[</code>’ and the closing ‘<code>]</code>’ is interpreted
<em>as if</em> it were in double quotes
(<a href="Shell-Grammar.html#Quoting">Quoting</a>). However, unlike double quotes
which normally cannot nest, subscript expressions may appear inside
double-quoted strings or inside other subscript expressions (or both!),
so the rules have two important differences.</p>
<p>The first difference is that brackets (‘<code>[</code>’ and ‘<code>]</code>’) must appear as
balanced pairs in a subscript expression unless they are preceded by a
backslash (‘<code>\</code>’). Therefore, within a subscript expression (and unlike
true double-quoting) the sequence ‘<code>\[</code>’ becomes ‘<code>[</code>’, and similarly
‘<code>\]</code>’ becomes ‘<code>]</code>’. This applies even in cases where a backslash is
not normally required; for example, the pattern ‘<code>[^[]</code>’ (to match any
character other than an open bracket) should be written ‘<code>[^\[]</code>’ in a
reverse-subscript pattern. However, note that ‘<code>\[^\[\]</code>’ and even
‘<code>\[^[]</code>’ mean the <em>same</em> thing, because backslashes are always
stripped when they appear before brackets!</p>
<p>The same rule applies to parentheses (‘<code>(</code>’ and ‘<code>)</code>’) and braces (‘<code>{</code>’
and ‘<code>}</code>’): they must appear either in balanced pairs or preceded by a
backslash, and backslashes that protect parentheses or braces are
removed during parsing. This is because parameter expansions may be
surrounded by balanced braces, and subscript flags are introduced by
balanced parentheses.</p>
<p>The second difference is that a double-quote (‘<code>&quot;</code>’) may appear as part
of a subscript expression without being preceded by a backslash, and
therefore that the two characters ‘<code>\&quot;</code>’ remain as two characters in the
subscript (in true double-quoting, ‘<code>\&quot;</code>’ becomes ‘<code>&quot;</code>’). However,
because of the standard shell quoting rules, any double-quotes that
appear must occur in balanced pairs unless preceded by a backslash. This
makes it more difficult to write a subscript expression that contains an
odd number of double-quote characters, but the reason for this
difference is so that when a subscript expression appears inside true
double-quotes, one can still write ‘<code>\&quot;</code>’ (rather than ‘<code>\\\&quot;</code>’) for
‘<code>&quot;</code>’.</p>
<p>To use an odd number of double quotes as a key in an assignment, use the
<code>typeset</code> builtin and an enclosing pair of double quotes; to refer to
the value of that key, again use double quotes:</p>
<div class="example">
<pre><code class="language-example">typeset -A aa
typeset &quot;aa[one\&quot;two\&quot;three\&quot;quotes]&quot;=QQQ
print &quot;$aa[one\&quot;two\&quot;three\&quot;quotes]&quot;
</code></pre>
</div>
<p>It is important to note that the quoting rules do not change when a
parameter expansion with a subscript is nested inside another subscript
expression. That is, it is not necessary to use additional backslashes
within the inner subscript expression; they are removed only once, from
the innermost subscript outwards. Parameters are also expanded from the
innermost subscript first, as each expansion is encountered left to
right in the outer expression.</p>
<p>A further complication arises from a way in which subscript parsing is
<em>not</em> different from double quote parsing. As in true double-quoting,
the sequences ‘<code>\*</code>’, and ‘<code>\@</code>’ remain as two characters when they
appear in a subscript expression. To use a literal ‘<code>*</code>’ or ‘<code>@</code>’ as an
associative array key, the ‘<code>e</code>’ flag must be used:</p>
<div class="example">
<pre><code class="language-example">typeset -A aa
aa[(e)*]=star
print $aa[(e)*]
</code></pre>
</div>
<p>A last detail must be considered when reverse subscripting is performed.
Parameters appearing in the subscript expression are first expanded and
then the complete expression is interpreted as a pattern. This has two
effects: first, parameters behave as if <code>GLOB_SUBST</code> were on (and it
cannot be turned off); second, backslashes are interpreted twice, once
when parsing the array subscript and again when parsing the pattern. In
a reverse subscript, it’s necessary to use <em>four</em> backslashes to cause a
single backslash to match literally in the pattern. For complex
patterns, it is often easiest to assign the desired pattern to a
parameter and then refer to that parameter in the subscript, because
then the backslashes, brackets, parentheses, etc., are seen only when
the complete expression is converted to a pattern. To match the value of
a parameter literally in a reverse subscript, rather than as a pattern,
use ‘<code>${(q``)``name``}</code>’ (<a href="Expansion.html#Parameter-Expansion">Parameter
Expansion</a>) to quote the expanded
value.</p>
<p>Note that the ‘<code>k</code>’ and ‘<code>K</code>’ flags are reverse subscripting for an
ordinary array, but are <em>not</em> reverse subscripting for an associative
array! (For an associative array, the keys in the array itself are
interpreted as patterns by those flags; the subscript is a plain string
in that case.)</p>
<p>One final note, not directly related to subscripting: the numeric names
of positional parameters (<a href="Parameters.html#Positional-Parameters">Positional
Parameters</a>) are parsed specially, so for
example ‘<code>$2foo</code>’ is equivalent to ‘<code>${2}foo</code>’. Therefore, to use
subscript syntax to extract a substring from a positional parameter, the
expansion must be surrounded by braces; for example, ‘<code>${2[3,5]}</code>’
evaluates to the third through fifth characters of the second positional
parameter, but ‘<code>$2[3,5]</code>’ is the entire second parameter concatenated
with the filename generation pattern ‘<code>[3,5]</code>’.</p>
<hr />
<p><span id="Positional-Parameters"></span>
<span id="Positional-Parameters-1"></span></p>
<h2 id="153-positional-parameters"><a class="header" href="#153-positional-parameters">15.3 Positional Parameters</a></h2>
<p>The positional parameters provide access to the command-line arguments
of a shell function, shell script, or the shell itself; see
<a href="Invocation.html#Invocation">Invocation</a>, and also
<a href="Functions.html#Functions">Functions</a>. The parameter <code>n</code>, where <code>n</code> is a
number, is the <code>n</code>th positional parameter. The parameter ‘<code>$0</code>’ is a
special case, see <a href="Parameters.html#Parameters-Set-By-The-Shell">Parameters Set By The
Shell</a>.</p>
<p>The parameters <code>*</code>, <code>@</code> and <code>argv</code> are arrays containing all the
positional parameters; thus ‘<code>$argv[``n``]</code>’, etc., is equivalent to
simply ‘<code>$``n</code>’. Note that the options <code>KSH_ARRAYS</code> or
<code>KSH_ZERO_SUBSCRIPT</code> apply to these arrays as well, so with either of
those options set, ‘<code>${argv[0]}</code>’ is equivalent to ‘<code>$1</code>’ and so on.</p>
<p>Positional parameters may be changed after the shell or function starts
by using the <code>set</code> builtin, by assigning to the <code>argv</code> array, or by
direct assignment of the form ‘<code>n``=``value</code>’ where <code>n</code> is the number of
the positional parameter to be changed. This also creates (with empty
values) any of the positions from 1 to <code>n</code> that do not already have
values. Note that, because the positional parameters form an array, an
array assignment of the form ‘<code>n``=(``value</code> ...<code>)</code>’ is allowed, and has
the effect of shifting all the values at positions greater than <code>n</code> by
as many positions as necessary to accommodate the new values.</p>
<hr />
<p><span id="Local-Parameters"></span>
<span id="Local-Parameters-1"></span></p>
<h2 id="154-local-parameters"><a class="header" href="#154-local-parameters">15.4 Local Parameters</a></h2>
<p>Shell function executions delimit scopes for shell parameters.
(Parameters are dynamically scoped.) The <code>typeset</code> builtin, and its
alternative forms <code>declare</code>, <code>integer</code>, <code>local</code> and <code>readonly</code> (but not
<code>export</code>), can be used to declare a parameter as being local to the
innermost scope.</p>
<p>When a parameter is read or assigned to, the innermost existing
parameter of that name is used. (That is, the local parameter hides any
less-local parameter.) However, assigning to a non-existent parameter,
or declaring a new parameter with <code>export</code>, causes it to be created in
the <em>outer</em>most scope.</p>
<p>Local parameters disappear when their scope ends. <code>unset</code> can be used to
delete a parameter while it is still in scope; any outer parameter of
the same name remains hidden.</p>
<p>Special parameters may also be made local; they retain their special
attributes unless either the existing or the newly-created parameter has
the <code>-h</code> (hide) attribute. This may have unexpected effects: there is no
default value, so if there is no assignment at the point the variable is
made local, it will be set to an empty value (or zero in the case of
integers). The following:</p>
<div class="example">
<pre><code class="language-example">typeset PATH=/new/directory:$PATH
</code></pre>
</div>
<p>is valid for temporarily allowing the shell or programmes called from it
to find the programs in <code>/new/directory</code> inside a function.</p>
<p>Note that the restriction in older versions of zsh that local parameters
were never exported has been removed.</p>
<hr />
<p><span id="Parameters-Set-By-The-Shell"></span>
<span id="Parameters-Set-By-The-Shell-1"></span></p>
<h2 id="155-parameters-set-by-the-shell"><a class="header" href="#155-parameters-set-by-the-shell">15.5 Parameters Set By The Shell</a></h2>
<p>In the parameter lists that follow, the mark ‘&lt;S&gt;’ indicates that the
parameter is special. ‘&lt;Z&gt;’ indicates that the parameter does not
exist when the shell initializes in <code>sh</code> or <code>ksh</code> emulation mode.</p>
<p>The following parameters are automatically set by the shell:</p>
<p><span id="index-_0021"></span></p>
<p><code>!</code> &lt;S&gt;</p>
<p>The process ID of the last command started in the background with <code>&amp;</code>,
put into the background with the <code>bg</code> builtin, or spawned with <code>coproc</code>.</p>
<p><span id="index-_0023"></span></p>
<p><code>#</code> &lt;S&gt;</p>
<p>The number of positional parameters in decimal. Note that some confusion
may occur with the syntax <code>$#``param</code> which substitutes the length of
<code>param</code>. Use <code>${#}</code> to resolve ambiguities. In particular, the sequence
‘<code>$#-``...</code>’ in an arithmetic expression is interpreted as the length
of the parameter <code>-</code>, q.v.</p>
<p><span id="index-ARGC"></span></p>
<p><code>ARGC</code> &lt;S&gt; &lt;Z&gt;</p>
<p>Same as <code>#</code>.</p>
<p><span id="index-_0024"></span></p>
<p><code>$</code> &lt;S&gt;</p>
<p>The process ID of this shell. Note that this indicates the original
shell started by invoking <code>zsh</code>; all processes forked from the shells
without executing a new program, such as subshells started by
<code>(``...``)</code>, substitute the same value.</p>
<p><span id="index-_002d-1"></span></p>
<p><code>-</code> &lt;S&gt;</p>
<p>Flags supplied to the shell on invocation or by the <code>set</code> or <code>setopt</code>
commands.</p>
<p><span id="index-_002a"></span></p>
<p><code>*</code> &lt;S&gt;</p>
<p>An array containing the positional parameters.</p>
<p><span id="index-argv"></span></p>
<p><code>argv</code> &lt;S&gt; &lt;Z&gt;</p>
<p>Same as <code>*</code>. Assigning to <code>argv</code> changes the local positional
parameters, but <code>argv</code> is <em>not</em> itself a local parameter. Deleting
<code>argv</code> with <code>unset</code> in any function deletes it everywhere, although only
the innermost positional parameter array is deleted (so <code>*</code> and <code>@</code> in
other scopes are not affected).</p>
<p><span id="index-_0040"></span></p>
<p><code>@</code> &lt;S&gt;</p>
<p>Same as <code>argv[@]</code>, even when <code>argv</code> is not set.</p>
<p><span id="index-_003f"></span></p>
<p><code>?</code> &lt;S&gt;</p>
<p>The exit status returned by the last command.</p>
<p><span id="index-0"></span></p>
<p><code>0</code> &lt;S&gt;</p>
<p>The name used to invoke the current shell, or as set by the <code>-c</code> command
line option upon invocation. If the <code>FUNCTION_ARGZERO</code> option is set,
<code>$0</code> is set upon entry to a shell function to the name of the function,
and upon entry to a sourced script to the name of the script, and reset
to its previous value when the function or script returns.</p>
<p><span id="index-status"></span></p>
<p><code>status</code> &lt;S&gt; &lt;Z&gt;</p>
<p>Same as <code>?</code>.</p>
<p><span id="index-pipestatus"></span></p>
<p><code>pipestatus</code> &lt;S&gt; &lt;Z&gt;</p>
<p>An array containing the exit statuses returned by all commands in the
last pipeline.</p>
<p><span id="index-_005f"></span></p>
<p><code>_</code> &lt;S&gt;</p>
<p>The last argument of the previous command. Also, this parameter is set
in the environment of every command executed to the full pathname of the
command.</p>
<p><span id="index-CPUTYPE"></span></p>
<p><code>CPUTYPE</code></p>
<p>The machine type (microprocessor class or machine model), as determined
at run time.</p>
<p><span id="index-EGID"></span></p>
<p><code>EGID</code> &lt;S&gt;</p>
<p>The effective group ID of the shell process. If you have sufficient
privileges, you may change the effective group ID of the shell process
by assigning to this parameter. Also (assuming sufficient privileges),
you may start a single command with a different effective group ID by
‘<code>(EGID=``gid``; command)</code>’</p>
<p>If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.</p>
<p><span id="index-EUID"></span></p>
<p><code>EUID</code> &lt;S&gt;</p>
<p>The effective user ID of the shell process. If you have sufficient
privileges, you may change the effective user ID of the shell process by
assigning to this parameter. Also (assuming sufficient privileges), you
may start a single command with a different effective user ID by
‘<code>(EUID=``uid``; command)</code>’</p>
<p>If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.</p>
<p><span id="index-ERRNO"></span></p>
<p><code>ERRNO</code> &lt;S&gt;</p>
<p>The value of errno (see man page errno(3)) as set by the most recently
failed system call. This value is system dependent and is intended for
debugging purposes. It is also useful with the <code>zsh/system</code> module which
allows the number to be turned into a name or message.</p>
<p><span id="index-FUNCNEST"></span></p>
<p><code>FUNCNEST</code> &lt;S&gt;</p>
<p>Integer. If greater than or equal to zero, the maximum nesting depth of
shell functions. When it is exceeded, an error is raised at the point
where a function is called. The default value is determined when the
shell is configured, but is typically 500. Increasing the value
increases the danger of a runaway function recursion causing the shell
to crash. Setting a negative value turns off the check.</p>
<p><span id="index-GID"></span></p>
<p><code>GID</code> &lt;S&gt;</p>
<p>The real group ID of the shell process. If you have sufficient
privileges, you may change the group ID of the shell process by
assigning to this parameter. Also (assuming sufficient privileges), you
may start a single command under a different group ID by ‘<code>(GID=``gid``; command)</code>’</p>
<p>If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.</p>
<p><span id="index-HISTCMD"></span></p>
<p><code>HISTCMD</code></p>
<p>The current history event number in an interactive shell, in other words
the event number for the command that caused <code>$HISTCMD</code> to be read. If
the current history event modifies the history, <code>HISTCMD</code> changes to the
new maximum history event number.</p>
<p><span id="index-HOST"></span></p>
<p><code>HOST</code></p>
<p>The current hostname.</p>
<p><span id="index-LINENO"></span></p>
<p><code>LINENO</code> &lt;S&gt;</p>
<p>The line number of the current line within the current script, sourced
file, or shell function being executed, whichever was started most
recently. Note that in the case of shell functions the line number
refers to the function as it appeared in the original definition, not
necessarily as displayed by the <code>functions</code> builtin.</p>
<p><span id="index-LOGNAME"></span></p>
<p><code>LOGNAME</code></p>
<p>If the corresponding variable is not set in the environment of the
shell, it is initialized to the login name corresponding to the current
login session. This parameter is exported by default but this can be
disabled using the <code>typeset</code> builtin. The value is set to the string
returned by the man page getlogin(3) system call if that is available.</p>
<p><span id="index-MACHTYPE"></span></p>
<p><code>MACHTYPE</code></p>
<p>The machine type (microprocessor class or machine model), as determined
at compile time.</p>
<p><span id="index-OLDPWD"></span></p>
<p><code>OLDPWD</code></p>
<p>The previous working directory. This is set when the shell initializes
and whenever the directory changes.</p>
<p><span id="index-OPTARG"></span></p>
<p><code>OPTARG</code> &lt;S&gt;</p>
<p>The value of the last option argument processed by the <code>getopts</code>
command.</p>
<p><span id="index-OPTIND"></span></p>
<p><code>OPTIND</code> &lt;S&gt;</p>
<p>The index of the last option argument processed by the <code>getopts</code>
command.</p>
<p><span id="index-OSTYPE"></span></p>
<p><code>OSTYPE</code></p>
<p>The operating system, as determined at compile time.</p>
<p><span id="index-PPID"></span></p>
<p><code>PPID</code> &lt;S&gt;</p>
<p>The process ID of the parent of the shell. As for <code>$$</code>, the value
indicates the parent of the original shell and does not change in
subshells.</p>
<p><span id="index-PWD"></span></p>
<p><code>PWD</code></p>
<p>The present working directory. This is set when the shell initializes
and whenever the directory changes.</p>
<p><span id="index-RANDOM"></span></p>
<p><code>RANDOM</code> &lt;S&gt;</p>
<p>A pseudo-random integer from 0 to 32767, newly generated each time this
parameter is referenced. The random number generator can be seeded by
assigning a numeric value to <code>RANDOM</code>.</p>
<p>sequence; subshells that reference <code>RANDOM</code> will result in identical
pseudo-random values unless the value of <code>RANDOM</code> is referenced or
seeded in the parent shell in between subshell invocations.</p>
<p><span id="index-SECONDS"></span></p>
<p><code>SECONDS</code> &lt;S&gt;</p>
<p>The number of seconds since shell invocation. If this parameter is
assigned a value, then the value returned upon reference will be the
value that was assigned plus the number of seconds since the assignment.</p>
<p>Unlike other special parameters, the type of the <code>SECONDS</code> parameter can
be changed using the <code>typeset</code> command. Only integer and one of the
floating point types are allowed. For example, ‘<code>typeset -F SECONDS</code>’
causes the value to be reported as a floating point number. The value is
available to microsecond accuracy, although the shell may show more or
fewer digits depending on the use of <code>typeset</code>. See the documentation
for the builtin <code>typeset</code> in <a href="Shell-Builtin-Commands.html#Shell-Builtin-Commands">Shell Builtin
Commands</a> for more
details.</p>
<p><span id="index-SHLVL"></span></p>
<p><code>SHLVL</code> &lt;S&gt;</p>
<p>Incremented by one each time a new shell is started.</p>
<p><span id="index-signals"></span></p>
<p><code>signals</code></p>
<p>An array containing the names of the signals. Note that with the
standard zsh numbering of array indices, where the first element has
index 1, the signals are offset by 1 from the signal number used by the
operating system. For example, on typical Unix-like systems <code>HUP</code> is
signal number 1, but is referred to as <code>$signals[2]</code>. This is because of
<code>EXIT</code> at position 1 in the array, which is used internally by zsh but
is not known to the operating system.</p>
<p><span id="index-TRY_005fBLOCK_005fERROR"></span></p>
<p><code>TRY_BLOCK_ERROR</code> &lt;S&gt;</p>
<p>In an <code>always</code> block, indicates whether the preceding list of code
caused an error. The value is 1 to indicate an error, 0 otherwise. It
may be reset, clearing the error condition. See <a href="Shell-Grammar.html#Complex-Commands">Complex
Commands</a></p>
<p><span id="index-TRY_005fBLOCK_005fINTERRUPT"></span></p>
<p><code>TRY_BLOCK_INTERRUPT</code> &lt;S&gt;</p>
<p>This variable works in a similar way to <code>TRY_BLOCK_ERROR</code>, but
represents the status of an interrupt from the signal SIGINT, which
typically comes from the keyboard when the user types <code>^C</code>. If set to 0,
any such interrupt will be reset; otherwise, the interrupt is propagated
after the <code>always</code> block.</p>
<p>Note that it is possible that an interrupt arrives during the execution
of the <code>always</code> block; this interrupt is also propagated.</p>
<p><span id="index-TTY"></span></p>
<p><code>TTY</code></p>
<p>The name of the tty associated with the shell, if any.</p>
<p><span id="index-TTYIDLE"></span></p>
<p><code>TTYIDLE</code> &lt;S&gt;</p>
<p>The idle time of the tty associated with the shell in seconds or -1 if
there is no such tty.</p>
<p><span id="index-UID"></span></p>
<p><code>UID</code> &lt;S&gt;</p>
<p>The real user ID of the shell process. If you have sufficient
privileges, you may change the user ID of the shell by assigning to this
parameter. Also (assuming sufficient privileges), you may start a single
command under a different user ID by ‘<code>(UID=``uid``; command)</code>’</p>
<p>If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.</p>
<p><span id="index-USERNAME"></span></p>
<p><code>USERNAME</code> &lt;S&gt;</p>
<p>The username corresponding to the real user ID of the shell process. If
you have sufficient privileges, you may change the username (and also
the user ID and group ID) of the shell by assigning to this parameter.
Also (assuming sufficient privileges), you may start a single command
under a different username (and user ID and group ID) by
‘<code>(USERNAME=``username``; command)</code>’</p>
<p><span id="index-VENDOR"></span></p>
<p><code>VENDOR</code></p>
<p>The vendor, as determined at compile time.</p>
<p><span id="index-zsh_005feval_005fcontext"></span>
<span id="index-ZSH_005fEVAL_005fCONTEXT"></span></p>
<p><code>zsh_eval_context</code> &lt;S&gt; &lt;Z&gt; (<code>ZSH_EVAL_CONTEXT</code> &lt;S&gt;)</p>
<p>An array (colon-separated list) indicating the context of shell code
that is being run. Each time a piece of shell code that is stored within
the shell is executed a string is temporarily appended to the array to
indicate the type of operation that is being performed. Read in order
the array gives an indication of the stack of operations being performed
with the most immediate context last.</p>
<p>Note that the variable does not give information on syntactic context
such as pipelines or subshells. Use <code>$ZSH_SUBSHELL</code> to detect subshells.</p>
<p>The context is one of the following:</p>
<ul>
<li>
<p><code>cmdarg</code><br />
Code specified by the <code>-c</code> option to the command line that invoked
the shell.</p>
</li>
<li>
<p><code>cmdsubst</code><br />
Command substitution using the <code>‘``...``‘</code> or <code>$(``...``)</code>
construct.</p>
</li>
<li>
<p><code>equalsubst</code><br />
File substitution using the <code>=(``...``)</code> construct.</p>
</li>
<li>
<p><code>eval</code><br />
Code executed by the <code>eval</code> builtin.</p>
</li>
<li>
<p><code>evalautofunc</code><br />
Code executed with the <code>KSH_AUTOLOAD</code> mechanism in order to define
an autoloaded function.</p>
</li>
<li>
<p><code>fc</code><br />
Code from the shell history executed by the <code>-e</code> option to the <code>fc</code>
builtin.</p>
</li>
<li>
<p><code>file</code><br />
Lines of code being read directly from a file, for example by the
<code>source</code> builtin.</p>
</li>
<li>
<p><code>filecode</code><br />
Lines of code being read from a <code>.zwc</code> file instead of directly from
the source file.</p>
</li>
<li>
<p><code>globqual</code><br />
Code executed by the <code>e</code> or <code>+</code> glob qualifier.</p>
</li>
<li>
<p><code>globsort</code><br />
Code executed to order files by the <code>o</code> glob qualifier.</p>
</li>
<li>
<p><code>insubst</code><br />
File substitution using the <code>&lt;(``...``)</code> construct.</p>
</li>
<li>
<p><code>loadautofunc</code><br />
Code read directly from a file to define an autoloaded function.</p>
</li>
<li>
<p><code>outsubst</code><br />
File substitution using the <code>&gt;(``...``)</code> construct.</p>
</li>
<li>
<p><code>sched</code><br />
Code executed by the <code>sched</code> builtin.</p>
</li>
<li>
<p><code>shfunc</code><br />
A shell function.</p>
</li>
<li>
<p><code>stty</code><br />
Code passed to <code>stty</code> by the <code>STTY</code> environment variable. Normally
this is passed directly to the system’s <code>stty</code> command, so this
value is unlikely to be seen in practice.</p>
</li>
<li>
<p><code>style</code><br />
Code executed as part of a style retrieved by the <code>zstyle</code> builtin
from the <code>zsh/zutil</code> module.</p>
</li>
<li>
<p><code>toplevel</code><br />
The highest execution level of a script or interactive shell.</p>
</li>
<li>
<p><code>trap</code><br />
Code executed as a trap defined by the <code>trap</code> builtin. Traps defined
as functions have the context <code>shfunc</code>. As traps are asynchronous
they may have a different hierarchy from other code.</p>
</li>
<li>
<p><code>zpty</code><br />
Code executed by the <code>zpty</code> builtin from the <code>zsh/zpty</code> module.</p>
</li>
<li>
<p><code>zregexparse-guard</code><br />
Code executed as a guard by the <code>zregexparse</code> command from the
<code>zsh/zutil</code> module.</p>
</li>
<li>
<p><code>zregexparse-action</code><br />
Code executed as an action by the <code>zregexparse</code> command from the
<code>zsh/zutil</code> module.</p>
</li>
</ul>
<p><span id="index-ZSH_005fARGZERO"></span></p>
<p><code>ZSH_ARGZERO</code></p>
<p>If zsh was invoked to run a script, this is the name of the script.
Otherwise, it is the name used to invoke the current shell. This is the
same as the value of <code>$0</code> when the <code>POSIX_ARGZERO</code> option is set, but is
always available.</p>
<p><span id="index-ZSH_005fEXECUTION_005fSTRING"></span></p>
<p><code>ZSH_EXECUTION_STRING</code></p>
<p>If the shell was started with the option <code>-c</code>, this contains the
argument passed to the option. Otherwise it is not set.</p>
<p><span id="index-ZSH_005fNAME"></span></p>
<p><code>ZSH_NAME</code></p>
<p>Expands to the basename of the command used to invoke this instance of
zsh.</p>
<p><span id="index-ZSH_005fPATCHLEVEL"></span></p>
<p><code>ZSH_PATCHLEVEL</code></p>
<p>The output of ‘<code>git describe –tags –long</code>’ for the zsh repository used
to build the shell. This is most useful in order to keep track of
versions of the shell during development between releases; hence most
users should not use it and should instead rely on <code>$ZSH_VERSION</code>.</p>
<p><code>zsh_scheduled_events</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fsched-Module">The zsh/sched Module</a>.</p>
<p><span id="index-ZSH_005fSCRIPT"></span></p>
<p><code>ZSH_SCRIPT</code></p>
<p>If zsh was invoked to run a script, this is the name of the script,
otherwise it is unset.</p>
<p><span id="index-ZSH_005fSUBSHELL-_003cS_003e"></span></p>
<p><code>ZSH_SUBSHELL</code></p>
<p>Readonly integer. Initially zero, incremented each time the shell forks
to create a subshell for executing code. Hence ‘<code>(print $ZSH_SUBSHELL)</code>’
and ‘<code>print $(print $ZSH_SUBSHELL)</code>’ output 1, while ‘<code>( (print $ZSH_SUBSHELL) )</code>’ outputs 2.</p>
<p><span id="index-ZSH_005fVERSION"></span></p>
<p><code>ZSH_VERSION</code></p>
<p>The version number of the release of zsh.</p>
<hr />
<p><span id="Parameters-Used-By-The-Shell"></span>
<span id="Parameters-Used-By-The-Shell-1"></span></p>
<h2 id="156-parameters-used-by-the-shell"><a class="header" href="#156-parameters-used-by-the-shell">15.6 Parameters Used By The Shell</a></h2>
<p>The following parameters are used by the shell. Again, ‘&lt;S&gt;’ indicates
that the parameter is special and ‘&lt;Z&gt;’ indicates that the parameter
does not exist when the shell initializes in <code>sh</code> or <code>ksh</code> emulation
mode.</p>
<p>In cases where there are two parameters with an upper- and lowercase
form of the same name, such as <code>path</code> and <code>PATH</code>, the lowercase form is
an array and the uppercase form is a scalar with the elements of the
array joined together by colons. These are similar to tied parameters
created via ‘<code>typeset -T</code>’. The normal use for the colon-separated form
is for exporting to the environment, while the array form is easier to
manipulate within the shell. Note that unsetting either of the pair will
unset the other; they retain their special properties when recreated,
and recreating one of the pair will recreate the other.</p>
<p><span id="index-ARGV0"></span></p>
<p><code>ARGV0</code></p>
<p>If exported, its value is used as the <code>argv[0]</code> of external commands.
Usually used in constructs like ‘<code>ARGV0=emacs nethack</code>’.</p>
<p><span id="index-editing-over-slow-connection"></span>
<span id="index-slow-connection_002c-editing-over"></span>
<span id="index-BAUD"></span></p>
<p><code>BAUD</code></p>
<p>The rate in bits per second at which data reaches the terminal. The line
editor will use this value in order to compensate for a slow terminal by
delaying updates to the display until necessary. If the parameter is
unset or the value is zero the compensation mechanism is turned off. The
parameter is not set by default.</p>
<p>This parameter may be profitably set in some circumstances, e.g. for
slow modems dialing into a communications server, or on a slow wide area
network. It should be set to the baud rate of the slowest part of the
link for best performance.</p>
<p><span id="index-cdpath"></span> <span id="index-CDPATH"></span></p>
<p><code>cdpath</code> &lt;S&gt; &lt;Z&gt; (<code>CDPATH</code> &lt;S&gt;)</p>
<p>An array (colon-separated list) of directories specifying the search
path for the <code>cd</code> command.</p>
<p><span id="index-COLUMNS"></span></p>
<p><code>COLUMNS</code> &lt;S&gt;</p>
<p>The number of columns for this terminal session. Used for printing
select lists and for the line editor.</p>
<p><span id="index-CORRECT_005fIGNORE"></span></p>
<p><code>CORRECT_IGNORE</code></p>
<p>If set, is treated as a pattern during spelling correction. Any
potential correction that matches the pattern is ignored. For example,
if the value is ‘<code>_*</code>’ then completion functions (which, by convention,
have names beginning with ‘<code>_</code>’) will never be offered as spelling
corrections. The pattern does not apply to the correction of file names,
as applied by the <code>CORRECT_ALL</code> option (so with the example just given
files beginning with ‘<code>_</code>’ in the current directory would still be
completed).</p>
<p><span id="index-CORRECT_005fIGNORE_005fFILE"></span></p>
<p><code>CORRECT_IGNORE_FILE</code></p>
<p>If set, is treated as a pattern during spelling correction of file
names. Any file name that matches the pattern is never offered as a
correction. For example, if the value is ‘<code>.*</code>’ then dot file names will
never be offered as spelling corrections. This is useful with the
<code>CORRECT_ALL</code> option.</p>
<p><span id="index-DIRSTACKSIZE"></span></p>
<p><code>DIRSTACKSIZE</code></p>
<p>The maximum size of the directory stack, by default there is no limit.
If the stack gets larger than this, it will be truncated automatically.
This is useful with the <code>AUTO_PUSHD</code> option.
<span id="index-AUTO_005fPUSHD_002c-use-of"></span></p>
<p><span id="index-ENV"></span></p>
<p><code>ENV</code></p>
<p>If the <code>ENV</code> environment variable is set when zsh is invoked as <code>sh</code> or
<code>ksh</code>, <code>$ENV</code> is sourced after the profile scripts. The value of <code>ENV</code>
is subjected to parameter expansion, command substitution, and
arithmetic expansion before being interpreted as a pathname. Note that
<code>ENV</code> is <em>not</em> used unless the shell is interactive and zsh is emulating
sh or ksh.</p>
<p><span id="index-FCEDIT"></span></p>
<p><code>FCEDIT</code></p>
<p>The default editor for the <code>fc</code> builtin. If <code>FCEDIT</code> is not set, the
parameter <code>EDITOR</code> is used; if that is not set either, a builtin
default, usually <code>vi</code>, is used.</p>
<p><span id="index-fignore"></span> <span id="index-FIGNORE"></span></p>
<p><code>fignore</code> &lt;S&gt; &lt;Z&gt; (<code>FIGNORE</code> &lt;S&gt;)</p>
<p>An array (colon separated list) containing the suffixes of files to be
ignored during filename completion. However, if completion only
generates files with suffixes in this list, then these files are
completed anyway.</p>
<p><span id="index-fpath"></span> <span id="index-FPATH"></span></p>
<p><code>fpath</code> &lt;S&gt; &lt;Z&gt; (<code>FPATH</code> &lt;S&gt;)</p>
<p>An array (colon separated list) of directories specifying the search
path for function definitions. This path is searched when a function
file is found, then it is read and executed in the current environment.</p>
<p><span id="index-histchars"></span></p>
<p><code>histchars</code> &lt;S&gt;</p>
<p>Three characters used by the shell’s history and lexical analysis
mechanism. The first character signals the start of a history expansion
(default ‘<code>!</code>’). The second character signals the start of a quick
history substitution (default ‘<code>^</code>’). The third character is the comment
character (default ‘<code>#</code>’).</p>
<p>The characters must be in the ASCII character set; any attempt to set
<code>histchars</code> to characters with a locale-dependent meaning will be
rejected with an error message.</p>
<p><span id="index-HISTCHARS"></span></p>
<p><code>HISTCHARS</code> &lt;S&gt; &lt;Z&gt;</p>
<p>Same as <code>histchars</code>. (Deprecated.)</p>
<p><span id="index-HISTFILE"></span></p>
<p><code>HISTFILE</code></p>
<p>The file to save the history in when an interactive shell exits. If
unset, the history is not saved.</p>
<p><span id="index-HISTORY_005fIGNORE"></span></p>
<p><code>HISTORY_IGNORE</code></p>
<p>If set, is treated as a pattern at the time history files are written.
Any potential history entry that matches the pattern is skipped. For
example, if the value is ‘<code>fc *</code>’ then commands that invoke the
interactive history editor are never written to the history file.</p>
<p>Note that <code>HISTORY_IGNORE</code> defines a single pattern: to specify
alternatives use the ‘<code>(``first``|``second``|``...``)</code>’ syntax.</p>
<p>Compare the <code>HIST_NO_STORE</code> option or the <code>zshaddhistory</code> hook, either
of which would prevent such commands from being added to the interactive
history at all. If you wish to use <code>HISTORY_IGNORE</code> to stop history
being added in the first place, you can define the following hook:</p>
<div class="example">
<pre><code class="language-example">zshaddhistory() {
emulate -L zsh
## uncomment if HISTORY_IGNORE
## should use EXTENDED_GLOB syntax
# setopt extendedglob
[[ $1 != ${~HISTORY_IGNORE} ]]
}
</code></pre>
</div>
<p><span id="index-HISTSIZE"></span></p>
<p><code>HISTSIZE</code> &lt;S&gt;</p>
<p>The maximum number of events stored in the internal history list. If you
use the <code>HIST_EXPIRE_DUPS_FIRST</code> option, setting this value larger than
the <code>SAVEHIST</code> size will give you the difference as a cushion for saving
duplicated history events.</p>
<p>If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.</p>
<p><span id="index-HOME"></span></p>
<p><code>HOME</code> &lt;S&gt;</p>
<p>The default argument for the <code>cd</code> command. This is not set automatically
by the shell in <code>sh</code>, <code>ksh</code> or <code>csh</code> emulation, but it is typically
present in the environment anyway, and if it becomes set it has its
usual special behaviour.</p>
<p><span id="index-IFS"></span></p>
<p><code>IFS</code> &lt;S&gt;</p>
<p>Internal field separators (by default space, tab, newline and NUL), that
are used to separate words which result from command or parameter
expansion and words read by the <code>read</code> builtin. Any characters from the
set space, tab and newline that appear in the IFS are called <em>IFS white
space</em>. One or more IFS white space characters or one non-IFS white
space character together with any adjacent IFS white space character
delimit a field. If an IFS white space character appears twice
consecutively in the IFS, this character is treated as if it were not an
IFS white space character.</p>
<p>If the parameter is unset, the default is used. Note this has a
different effect from setting the parameter to an empty string.</p>
<p><span id="index-KEYBOARD_005fHACK"></span></p>
<p><code>KEYBOARD_HACK</code></p>
<p>This variable defines a character to be removed from the end of the
command line before interpreting it (interactive shells only). It is
intended to fix the problem with keys placed annoyingly close to return
and replaces the <code>SUNKEYBOARDHACK</code> option which did this for backquotes
only. Should the chosen character be one of singlequote, doublequote or
backquote, there must also be an odd number of them on the command line
for the last one to be removed.</p>
<p>For backward compatibility, if the <code>SUNKEYBOARDHACK</code> option is
explicitly set, the value of <code>KEYBOARD_HACK</code> reverts to backquote. If
the option is explicitly unset, this variable is set to empty.</p>
<p><span id="index-KEYTIMEOUT"></span></p>
<p><code>KEYTIMEOUT</code></p>
<p>The time the shell waits, in hundredths of seconds, for another key to
be pressed when reading bound multi-character sequences.</p>
<p><span id="index-LANG"></span></p>
<p><code>LANG</code> &lt;S&gt;</p>
<p>This variable determines the locale category for any category not
specifically selected via a variable starting with ‘<code>LC_</code>’.</p>
<p><span id="index-LC_005fALL"></span></p>
<p><code>LC_ALL</code> &lt;S&gt;</p>
<p>This variable overrides the value of the ‘<code>LANG</code>’ variable and the value
of any of the other variables starting with ‘<code>LC_</code>’.</p>
<p><span id="index-LC_005fCOLLATE"></span></p>
<p><code>LC_COLLATE</code> &lt;S&gt;</p>
<p>This variable determines the locale category for character collation
information within ranges in glob brackets and for sorting.</p>
<p><span id="index-LC_005fCTYPE"></span></p>
<p><code>LC_CTYPE</code> &lt;S&gt;</p>
<p>This variable determines the locale category for character handling
functions. If the <code>MULTIBYTE</code> option is in effect this variable or
<code>LANG</code> should contain a value that reflects the character set in use,
even if it is a single-byte character set, unless only the 7-bit subset
(ASCII) is used. For example, if the character set Linux distributions)
or <code>en_US.ISO8859-1</code> (MacOS).</p>
<p><span id="index-LC_005fMESSAGES"></span></p>
<p><code>LC_MESSAGES</code> &lt;S&gt;</p>
<p>This variable determines the language in which messages should be
written. Note that zsh does not use message catalogs.</p>
<p><span id="index-LC_005fNUMERIC"></span></p>
<p><code>LC_NUMERIC</code> &lt;S&gt;</p>
<p>This variable affects the decimal point character and thousands
separator character for the formatted input/output functions and string
conversion functions. Note that zsh ignores this setting when parsing
floating point mathematical expressions.</p>
<p><span id="index-LC_005fTIME"></span></p>
<p><code>LC_TIME</code> &lt;S&gt;</p>
<p>This variable determines the locale category for date and time
formatting in prompt escape sequences.</p>
<p><span id="index-LINES"></span></p>
<p><code>LINES</code> &lt;S&gt;</p>
<p>The number of lines for this terminal session. Used for printing select
lists and for the line editor.</p>
<p><span id="index-LISTMAX"></span></p>
<p><code>LISTMAX</code></p>
<p>In the line editor, the number of matches to list without asking most as
many lines as given by the absolute value. If set to zero, the shell
asks only if the top of the listing would scroll off the screen.</p>
<p><span id="index-LOGCHECK"></span></p>
<p><code>LOGCHECK</code></p>
<p>The interval in seconds between checks for login/logout activity using
the <code>watch</code> parameter.</p>
<p><span id="index-MAIL"></span></p>
<p><code>MAIL</code></p>
<p>If this parameter is set and <code>mailpath</code> is not set, the shell looks for
mail in the specified file.</p>
<p><span id="index-MAILCHECK"></span></p>
<p><code>MAILCHECK</code></p>
<p>The interval in seconds between checks for new mail.</p>
<p><span id="index-mailpath"></span> <span id="index-MAILPATH"></span></p>
<p><code>mailpath</code> &lt;S&gt; &lt;Z&gt; (<code>MAILPATH</code> &lt;S&gt;)</p>
<p>An array (colon-separated list) of filenames to check for new mail. Each
filename can be followed by a ‘<code>?</code>’ and a message that will be printed.
The message will undergo parameter expansion, command substitution and
arithmetic expansion with the variable <code>$_</code> defined as the name of the
file that has changed. The default message is ‘<code>You have new mail</code>’. If
an element is a directory instead of a file the shell will recursively
check every file in every subdirectory of the element.</p>
<p><span id="index-manpath"></span> <span id="index-MANPATH"></span></p>
<p><code>manpath</code> &lt;S&gt; &lt;Z&gt; (<code>MANPATH</code> &lt;S&gt; &lt;Z&gt;)</p>
<p>An array (colon-separated list) whose value is not used by the shell.
The <code>manpath</code> array can be useful, however, since setting it also sets
<code>MANPATH</code>, and vice versa.</p>
<p><code>match</code></p>
<p><code>mbegin</code></p>
<p><code>mend</code></p>
<p>Arrays set by the shell when the <code>b</code> globbing flag is used in pattern
matches. See the subsection <em>Globbing flags</em> in <a href="Expansion.html#Filename-Generation">Filename
Generation</a>.</p>
<p><code>MATCH</code></p>
<p><code>MBEGIN</code></p>
<p><code>MEND</code></p>
<p>Set by the shell when the <code>m</code> globbing flag is used in pattern matches.
See the subsection <em>Globbing flags</em> in <a href="Expansion.html#Filename-Generation">Filename
Generation</a>.</p>
<p><span id="index-module_005fpath"></span>
<span id="index-MODULE_005fPATH"></span></p>
<p><code>module_path</code> &lt;S&gt; &lt;Z&gt; (<code>MODULE_PATH</code> &lt;S&gt;)</p>
<p>An array (colon-separated list) of directories that <code>zmodload</code> searches
for dynamically loadable modules. This is initialized to a standard
pathname, usually ‘<code>/usr/local/lib/zsh/$ZSH_VERSION</code>’. (The
‘<code>/usr/local/lib</code>’ part varies from installation to installation.) For
security reasons, any value set in the environment when the shell is
started will be ignored.</p>
<p>These parameters only exist if the installation supports dynamic module
loading.</p>
<p><span id="index-NULLCMD"></span>
<span id="index-null-command-style"></span>
<span id="index-csh_002c-null-command-style"></span>
<span id="index-ksh_002c-null-command-style"></span></p>
<p><code>NULLCMD</code> &lt;S&gt;</p>
<p>The command name to assume if a redirection is specified with no
command. Defaults to <code>cat</code>. For sh/ksh behavior, change this to <code>:</code>. For
csh-like behavior, unset this parameter; the shell will print an error
message if null commands are entered.</p>
<p><span id="index-path"></span> <span id="index-PATH"></span></p>
<p><code>path</code> &lt;S&gt; &lt;Z&gt; (<code>PATH</code> &lt;S&gt;)</p>
<p>An array (colon-separated list) of directories to search for commands.
When this parameter is set, each directory is scanned</p>
<p><span id="index-POSTEDIT"></span></p>
<p><code>POSTEDIT</code> &lt;S&gt;</p>
<p>This string is output whenever the line editor exits. It usually
contains termcap strings to reset the terminal.</p>
<p><span id="index-PROMPT"></span></p>
<p><code>PROMPT</code> &lt;S&gt; &lt;Z&gt;</p>
<p><span id="index-PROMPT2"></span></p>
<p><code>PROMPT2</code> &lt;S&gt; &lt;Z&gt;</p>
<p><span id="index-PROMPT3"></span></p>
<p><code>PROMPT3</code> &lt;S&gt; &lt;Z&gt;</p>
<p><span id="index-PROMPT4"></span></p>
<p><code>PROMPT4</code> &lt;S&gt; &lt;Z&gt;</p>
<p>Same as <code>PS1</code>, <code>PS2</code>, <code>PS3</code> and <code>PS4</code>, respectively.</p>
<p><span id="index-prompt"></span></p>
<p><code>prompt</code> &lt;S&gt; &lt;Z&gt;</p>
<p>Same as <code>PS1</code>.</p>
<p><span id="index-PROMPT_005fEOL_005fMARK"></span></p>
<p><code>PROMPT_EOL_MARK</code></p>
<p>When the <code>PROMPT_CR</code> and <code>PROMPT_SP</code> options are set, the
<code>PROMPT_EOL_MARK</code> parameter can be used to customize how the end of
partial lines are shown. This parameter undergoes prompt expansion, with
the <code>PROMPT_PERCENT</code> option set. If not set, the default behavior is
equivalent to the value ‘<code>%B%S%#%s%b</code>’.</p>
<p><span id="index-PS1"></span></p>
<p><code>PS1</code> &lt;S&gt;</p>
<p>The primary prompt string, printed before a command is read. It
undergoes a special form of expansion before being displayed; see
<a href="Prompt-Expansion.html#Prompt-Expansion">Prompt Expansion</a>. The default
is ‘<code>%m%# </code>’.</p>
<p><span id="index-PS2"></span></p>
<p><code>PS2</code> &lt;S&gt;</p>
<p>The secondary prompt, printed when the shell needs more information to
complete a command. It is expanded in the same way as <code>PS1</code>. The default
is ‘<code>%_&gt; </code>’, which displays any shell constructs or quotation marks
which are currently being processed.</p>
<p><span id="index-PS3"></span></p>
<p><code>PS3</code> &lt;S&gt;</p>
<p>Selection prompt used within a <code>select</code> loop. It is expanded in the same
way as <code>PS1</code>. The default is ‘<code>?# </code>’.</p>
<p><span id="index-PS4"></span></p>
<p><code>PS4</code> &lt;S&gt;</p>
<p>The execution trace prompt. Default is ‘<code>+%N:%i&gt; </code>’, which displays
the name of the current shell structure and the line number within it.
In sh or ksh emulation, the default is ‘<code>+ </code>’.</p>
<p><span id="index-psvar"></span> <span id="index-PSVAR"></span></p>
<p><code>psvar</code> &lt;S&gt; &lt;Z&gt; (<code>PSVAR</code> &lt;S&gt;)</p>
<p>An array (colon-separated list) whose elements can be used in <code>PROMPT</code>
strings. Setting <code>psvar</code> also sets <code>PSVAR</code>, and vice versa.</p>
<p><span id="index-READNULLCMD"></span></p>
<p><code>READNULLCMD</code> &lt;S&gt;</p>
<p>The command name to assume if a single input redirection is specified
with no command. Defaults to <code>more</code>.</p>
<p><span id="index-REPORTMEMORY"></span></p>
<p><code>REPORTMEMORY</code></p>
<p>If nonnegative, commands whose maximum resident set size (roughly
speaking, main memory usage) in kilobytes is greater than this value
have timing statistics reported. The format used to output statistics is
the value of the <code>TIMEFMT</code> parameter, which is the same as for the
<code>REPORTTIME</code> variable and the <code>time</code> builtin; note that by default this
does not output memory usage. Appending <code>&quot; max RSS %M&quot;</code> to the value of
<code>TIMEFMT</code> causes it to output the value that triggered the report. If
<code>REPORTTIME</code> is also in use, at most a single report is printed for both
triggers. This feature requires the <code>getrusage()</code> system call, commonly
supported by modern Unix-like systems.</p>
<p><span id="index-REPORTTIME"></span></p>
<p><code>REPORTTIME</code></p>
<p>If nonnegative, commands whose combined user and system execution times
(measured in seconds) are greater than this value have timing statistics
printed for them. Output is suppressed for commands executed within the
line editor, including completion; commands explicitly marked with the
<code>time</code> keyword still cause the summary to be printed in this case.</p>
<p><span id="index-REPLY"></span></p>
<p><code>REPLY</code></p>
<p>This parameter is reserved by convention to pass string values between
shell scripts and shell builtins in situations where a function call or
redirection are impossible or undesirable. The <code>read</code> builtin and the
<code>select</code> complex command may set <code>REPLY</code>, and filename generation both
sets and examines its value when evaluating certain expressions. Some
modules also employ <code>REPLY</code> for similar purposes.</p>
<p><span id="index-reply"></span></p>
<p><code>reply</code></p>
<p>As <code>REPLY</code>, but for array values rather than strings.</p>
<p><span id="index-RPROMPT"></span></p>
<p><code>RPROMPT</code> &lt;S&gt;</p>
<p><span id="index-RPS1"></span></p>
<p><code>RPS1</code> &lt;S&gt;</p>
<p>This prompt is displayed on the right-hand side of the screen when the
primary prompt is being displayed on the left. This does not work if the
<code>SINGLE_LINE_ZLE</code> option is set. It is expanded in the same way as
<code>PS1</code>.</p>
<p><span id="index-RPROMPT2"></span></p>
<p><code>RPROMPT2</code> &lt;S&gt;</p>
<p><span id="index-RPS2"></span></p>
<p><code>RPS2</code> &lt;S&gt;</p>
<p>This prompt is displayed on the right-hand side of the screen when the
secondary prompt is being displayed on the left. This does not work if
the <code>SINGLE_LINE_ZLE</code> option is set. It is expanded in the same way as
<code>PS2</code>.</p>
<p><span id="index-SAVEHIST"></span></p>
<p><code>SAVEHIST</code></p>
<p>The maximum number of history events to save in the history file.</p>
<p>If this is made local, it is not implicitly set to 0, but may be
explicitly set locally.</p>
<p><span id="index-SPROMPT"></span></p>
<p><code>SPROMPT</code> &lt;S&gt;</p>
<p>The prompt used for spelling correction. The sequence ‘<code>%R</code>’ expands to
the string which presumably needs spelling correction, and ‘<code>%r</code>’
expands to the proposed correction. All other prompt escapes are also
allowed.</p>
<p>The actions available at the prompt are <code>[nyae]</code>:</p>
<ul>
<li>
<p><code>n</code> (‘no’) (default)<br />
Discard the correction and run the command.</p>
</li>
<li>
<p><code>y</code> (‘yes’)<br />
Make the correction and run the command.</p>
</li>
<li>
<p><code>a</code> (‘abort’)<br />
Discard the entire command line without running it.</p>
</li>
<li>
<p><code>e</code> (‘edit’)<br />
Resume editing the command line.</p>
</li>
</ul>
<p><span id="index-STTY"></span></p>
<p><code>STTY</code></p>
<p>If this parameter is set in a command’s environment, the shell runs the
<code>stty</code> command with the value of this parameter as arguments in order to
set up the terminal before executing the command. The modes apply only
to the command, and are reset when it finishes or is suspended. If the
command is suspended and continued later with the <code>fg</code> or <code>wait</code>
builtins it will see the modes specified by <code>STTY</code>, as if it were not
suspended. This (intentionally) does not apply if the command is
continued via ‘<code>kill -CONT</code>’. <code>STTY</code> is ignored if the command is run in
the background, or if it is in the environment of the shell but not
explicitly assigned to in the input line. This avoids running stty at
every external command by accidentally exporting it. Also note that
<code>STTY</code> should not be used for window size specifications; these will not
be local to the command.</p>
<p><span id="index-TERM"></span></p>
<p><code>TERM</code> &lt;S&gt;</p>
<p>The type of terminal in use. This is used when looking up termcap
sequences. An assignment to <code>TERM</code> causes zsh to re-initialize the
terminal, even if the value does not change (e.g., ‘<code>TERM=$TERM</code>’). It
is necessary to make such an assignment upon any change to the terminal
definition database or terminal type in order for the new settings to
take effect.</p>
<p><span id="index-TERMINFO"></span></p>
<p><code>TERMINFO</code> &lt;S&gt;</p>
<p>A reference to your terminfo database, used by the ‘terminfo’ library
when the system has it; see man page terminfo(5). If set, this causes
the shell to reinitialise the terminal, making the workaround
‘<code>TERM=$TERM</code>’ unnecessary.</p>
<p><span id="index-TERMINFO_005fDIRS"></span></p>
<p><code>TERMINFO_DIRS</code> &lt;S&gt;</p>
<p>A colon-seprarated list of terminfo databases, used by the ‘terminfo’
library when the system has it; see man page terminfo(5). This variable
is only used by certain terminal libraries, in particular ncurses; see
man page terminfo(5) to check support on your system. If set, this
causes the shell to reinitialise the terminal, making the workaround
‘<code>TERM=$TERM</code>’ unnecessary. Note that unlike other colon-separated
arrays this is not tied to a zsh array.</p>
<p><span id="index-TIMEFMT"></span></p>
<p><code>TIMEFMT</code></p>
<p>The format of process time reports with the <code>time</code> keyword. The default
is ‘<code>%J %U user %S system %P cpu %*E total</code>’. Recognizes the following
escape sequences, although not all may be available on all systems, and
some that are available may not be useful:</p>
<ul>
<li>
<p><code>%%</code><br />
A ‘<code>%</code>’.</p>
</li>
<li>
<p><code>%U</code><br />
CPU seconds spent in user mode.</p>
</li>
<li>
<p><code>%S</code><br />
CPU seconds spent in kernel mode.</p>
</li>
<li>
<p><code>%E</code><br />
Elapsed time in seconds.</p>
</li>
<li>
<p><code>%P</code><br />
The CPU percentage, computed as 100*(<code>%U</code>+<code>%S</code>)/<code>%E</code>.</p>
</li>
<li>
<p><code>%W</code><br />
Number of times the process was swapped.</p>
</li>
<li>
<p><code>%X</code><br />
The average amount in (shared) text space used in kilobytes.</p>
</li>
<li>
<p><code>%D</code><br />
The average amount in (unshared) data/stack space used in kilobytes.</p>
</li>
<li>
<p><code>%K</code><br />
The total space used (<code>%X</code>+<code>%D</code>) in kilobytes.</p>
</li>
<li>
<p><code>%M</code><br />
The maximum memory the process had in use at any time in kilobytes.</p>
</li>
<li>
<p><code>%F</code><br />
The number of major page faults (page needed to be brought from
disk).</p>
</li>
<li>
<p><code>%R</code><br />
The number of minor page faults.</p>
</li>
<li>
<p><code>%I</code><br />
The number of input operations.</p>
</li>
<li>
<p><code>%O</code><br />
The number of output operations.</p>
</li>
<li>
<p><code>%r</code><br />
The number of socket messages received.</p>
</li>
<li>
<p><code>%s</code><br />
The number of socket messages sent.</p>
</li>
<li>
<p><code>%k</code><br />
The number of signals received.</p>
</li>
<li>
<p><code>%w</code><br />
Number of voluntary context switches (waits).</p>
</li>
<li>
<p><code>%c</code><br />
Number of involuntary context switches.</p>
</li>
<li>
<p><code>%J</code><br />
The name of this job.</p>
</li>
</ul>
<p>A star may be inserted between the percent sign and flags printing time
(e.g., ‘<code>%*E</code>’); this causes the time to be printed in
‘<code>hh``:``mm``:``ss``.``ttt</code>’ format (hours and minutes are only
printed if they are not zero). Alternatively, ‘<code>m</code>’ or ‘<code>u</code>’ may be used
(e.g., ‘<code>%mE</code>’) to produce time output in milliseconds or microseconds,
respectively.</p>
<p><span id="index-TMOUT"></span></p>
<p><code>TMOUT</code></p>
<p>If this parameter is nonzero, the shell will receive an <code>ALRM</code> signal if
a command is not entered within the specified number of seconds after
issuing a prompt. If there is a trap on <code>SIGALRM</code>, it will be executed
and a new alarm is scheduled using the value of the <code>TMOUT</code> parameter
after executing the trap. If no trap is set, and the idle time of the
terminal is not less than the value of the <code>TMOUT</code> parameter, zsh
terminates. Otherwise a new alarm is scheduled to <code>TMOUT</code> seconds after
the last keypress.</p>
<p><span id="index-TMPPREFIX"></span></p>
<p><code>TMPPREFIX</code></p>
<p>A pathname prefix which the shell will use for all temporary files. Note
that this should include an initial part for the file name as well as
any directory names. The default is ‘<code>/tmp/zsh</code>’.</p>
<p><span id="index-TMPSUFFIX"></span></p>
<p><code>TMPSUFFIX</code></p>
<p>A filename suffix which the shell will use for temporary files created
by process substitutions (e.g., ‘<code>=(list)</code>’). Note that the value should
include a leading dot ‘<code>.</code>’ if intended to be interpreted as a file
extension. The default is not to append any suffix, thus this parameter
should be assigned only when needed and then unset again.</p>
<p><span id="index-watch"></span> <span id="index-WATCH"></span></p>
<p><code>watch</code> &lt;S&gt; &lt;Z&gt; (<code>WATCH</code> &lt;S&gt;)</p>
<p>An array (colon-separated list) of login/logout events to report.</p>
<p>If it contains the single word ‘<code>all</code>’, then all login/logout events are
reported. If it contains the single word ‘<code>notme</code>’, then all events are
reported as with ‘<code>all</code>’ except <code>$USERNAME</code>.</p>
<p>An entry in this list may consist of a username, an ‘<code>@</code>’ followed by a
remote hostname, and a ‘<code>%</code>’ followed by a line (tty). Any of these may
be a pattern (be sure to quote this during the assignment to <code>watch</code> so
that it does not immediately perform file generation); the setting of
the <code>EXTENDED_GLOB</code> option is respected. Any or all of these components
may be present in an entry; if a login/logout event matches all of them,
it is reported.</p>
<p>For example, with the <code>EXTENDED_GLOB</code> option set, the following:</p>
<div class="example">
<pre><code class="language-example">watch=('^(pws|barts)')
</code></pre>
</div>
<p>causes reports for activity associated with any user other than <code>pws</code> or
<code>barts</code>.</p>
<p><span id="index-WATCHFMT"></span></p>
<p><code>WATCHFMT</code></p>
<p>The format of login/logout reports if the <code>watch</code> parameter is set.
Default is ‘<code>%n has %a %l from %m</code>’. Recognizes the following escape
sequences:</p>
<ul>
<li>
<p><code>%n</code><br />
The name of the user that logged in/out.</p>
</li>
<li>
<p><code>%a</code><br />
The observed action, i.e. &quot;logged on&quot; or &quot;logged off&quot;.</p>
</li>
<li>
<p><code>%l</code><br />
The line (tty) the user is logged in on.</p>
</li>
<li>
<p><code>%M</code><br />
The full hostname of the remote host.</p>
</li>
<li>
<p><code>%m</code><br />
The hostname up to the first ‘<code>.</code>’. If only the IP address is
available or the utmp field contains the name of an X-windows
display, the whole name is printed.</p>
<p><em>NOTE:</em> The ‘<code>%m</code>’ and ‘<code>%M</code>’ escapes will work only if there is a
host name field in the utmp on your machine. Otherwise they are
treated as ordinary strings.</p>
</li>
<li>
<p><code>%S</code> (<code>%s</code>)<br />
Start (stop) standout mode.</p>
</li>
<li>
<p><code>%U</code> (<code>%u</code>)<br />
Start (stop) underline mode.</p>
</li>
<li>
<p><code>%B</code> (<code>%b</code>)<br />
Start (stop) boldface mode.</p>
</li>
<li>
<p><code>%t</code><br />
<code>%@</code><br />
The time, in 12-hour, am/pm format.</p>
</li>
<li>
<p><code>%T</code><br />
The time, in 24-hour format.</p>
</li>
<li>
<p><code>%w</code><br />
The date in ‘<code>day``-``dd</code>’ format.</p>
</li>
<li>
<p><code>%W</code><br />
The date in ‘<code>mm``/``dd``/``yy</code>’ format.</p>
</li>
<li>
<p><code>%D</code><br />
The date in ‘<code>yy``-``mm``-``dd</code>’ format.</p>
</li>
<li>
<p><code>%D{``string``}</code><br />
The date formatted as <code>string</code> using the <code>strftime</code> function, with
zsh extensions as described by <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>.</p>
</li>
<li>
<p><code>%(``x``:``true-text``:``false-text``)</code><br />
Specifies a ternary expression. The character following the <code>x</code> is
arbitrary; the same character is used to separate the text for the
&quot;true&quot; result from that for the &quot;false&quot; result. Both the separator
and the right parenthesis may be escaped with a backslash. Ternary
expressions may be nested.</p>
<p>The test character <code>x</code> may be any one of ‘<code>l</code>’, ‘<code>n</code>’, ‘<code>m</code>’ or
‘<code>M</code>’, which indicate a ‘true’ result if the corresponding
escape sequence would return a non-empty value; or it may be ‘<code>a</code>’,
which indicates a ‘true’ result if the watched user has logged in,
or ‘false’ if he has logged out. Other characters evaluate to
neither true nor false; the entire expression is omitted in this
case.</p>
<p>If the result is ‘true’, then the <code>true-text</code> is formatted according
to the rules above and printed, and the <code>false-text</code> is skipped. If
‘false’, the <code>true-text</code> is skipped and the <code>false-text</code> is
formatted and printed. Either or both of the branches may be empty,
but both separators must be present in any case.</p>
</li>
</ul>
<p><span id="index-WORDCHARS"></span></p>
<p><code>WORDCHARS</code> &lt;S&gt;</p>
<p>A list of non-alphanumeric characters considered part of a word by the
line editor.</p>
<p><span id="index-ZBEEP"></span></p>
<p><code>ZBEEP</code></p>
<p>If set, this gives a string of characters, which can use all the same
codes as the <code>bindkey</code> command as described in <a href="Zsh-Modules.html#The-zsh_002fzle-Module">The zsh/zle
Module</a>, that will be output to
the terminal instead of beeping. This may have a visible instead of an
audible effect; for example, the string ‘<code>\e[?5h\e[?5l</code>’ on a vt100 or
xterm will have the effect of flashing reverse video on and off (if you
usually use reverse video, you should use the string ‘<code>\e[?5l\e[?5h</code>’
instead). This takes precedence over the <code>NOBEEP</code> option.</p>
<p><span id="index-ZDOTDIR"></span></p>
<p><code>ZDOTDIR</code></p>
<p>The directory to search for shell startup files (.zshrc, etc), if not
<code>$HOME</code>.</p>
<p><span id="index-zle_005fbracketed_005fpaste"></span>
<span id="index-bracketed-paste"></span>
<span id="index-enabling-bracketed-paste"></span></p>
<p><code>zle_bracketed_paste</code></p>
<p>Many terminal emulators have a feature that allows applications to
identify when text is pasted into the terminal rather than being typed
normally. For ZLE, this means that special characters such as tabs and
newlines can be inserted instead of invoking editor commands.
Furthermore, pasted text forms a single undo event and if the region is
active, pasted text will replace the region.</p>
<p>This two-element array contains the terminal escape sequences for
enabling and disabling the feature. These escape sequences are used to
enable bracketed paste when ZLE is active and disable it at other times.
Unsetting the parameter has the effect of ensuring that bracketed paste
remains disabled.</p>
<p><span id="index-zle_005fhighlight"></span></p>
<p><code>zle_highlight</code></p>
<p>An array describing contexts in which ZLE should highlight the input
text. See <a href="Zsh-Line-Editor.html#Character-Highlighting">Character
Highlighting</a>.</p>
<p><span id="index-ZLE_005fLINE_005fABORTED"></span></p>
<p><code>ZLE_LINE_ABORTED</code></p>
<p>This parameter is set by the line editor when an error occurs. It
contains the line that was being edited at the point of the error.
‘<code>print -zr – $ZLE_LINE_ABORTED</code>’ can be used to recover the line.
Only the most recent line of this kind is remembered.</p>
<p><span id="index-ZLE_005fREMOVE_005fSUFFIX_005fCHARS"></span>
<span id="index-ZLE_005fSPACE_005fSUFFIX_005fCHARS"></span></p>
<p><code>ZLE_REMOVE_SUFFIX_CHARS</code></p>
<p><code>ZLE_SPACE_SUFFIX_CHARS</code></p>
<p>These parameters are used by the line editor. In certain circumstances
suffixes (typically space or slash) added by the completion system will
be removed automatically, either because the next editing command as
requiring the suffix to be removed.</p>
<p>These variables can contain the sets of characters that will cause the
suffix to be removed. If <code>ZLE_REMOVE_SUFFIX_CHARS</code> is set, those
characters will cause the suffix to be removed; if
<code>ZLE_SPACE_SUFFIX_CHARS</code> is set, those characters will cause the suffix
to be removed and replaced by a space.</p>
<p>If <code>ZLE_REMOVE_SUFFIX_CHARS</code> is not set, the default behaviour is
equivalent to:</p>
<div class="example">
<pre><code class="language-example">ZLE_REMOVE_SUFFIX_CHARS=$' \t\n;&amp;|'
</code></pre>
</div>
<p>If <code>ZLE_REMOVE_SUFFIX_CHARS</code> is set but is empty, no characters have
this behaviour. <code>ZLE_SPACE_SUFFIX_CHARS</code> takes precedence, so that the
following:</p>
<div class="example">
<pre><code class="language-example">ZLE_SPACE_SUFFIX_CHARS=$'&amp;|'
</code></pre>
</div>
<p>causes the characters ‘<code>&amp;</code>’ and ‘<code>|</code>’ to remove the suffix but to
replace it with a space.</p>
<p>To illustrate the difference, suppose that the option
<code>AUTO_REMOVE_SLASH</code> is in effect and the directory <code>DIR</code> has just been
completed, with an appended <code>/</code>, following which the user types ‘<code>&amp;</code>’.
The default result is ‘<code>DIR&amp;</code>’. With <code>ZLE_REMOVE_SUFFIX_CHARS</code> set but
without including ‘<code>&amp;</code>’ the result is ‘<code>DIR/&amp;</code>’. With
<code>ZLE_SPACE_SUFFIX_CHARS</code> set to include ‘<code>&amp;</code>’ the result is ‘<code>DIR &amp;</code>’.</p>
<p>Note that certain completions may provide their own suffix removal or
replacement behaviour which overrides the values described here. See the
completion system documentation in <a href="Completion-System.html#Completion-System">Completion
System</a>.</p>
<p><span id="index-ZLE_005fRPROMPT_005fINDENT"></span></p>
<p><code>ZLE_RPROMPT_INDENT</code> &lt;S&gt;</p>
<p>If set, used to give the indentation between the right hand side of the
right prompt in the line editor as given by <code>RPS1</code> or <code>RPROMPT</code> and the
right hand side of the screen. If not set, the value 1 is used.</p>
<p>Typically this will be used to set the value to 0 so that the prompt
appears flush with the right hand side of the screen. This is not the
default as many terminals do not handle this correctly, in particular
when the prompt appears at the extreme bottom right of the screen.
Recent virtual terminals are more likely to handle this case correctly.
Some experimentation is necessary.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Options.html#16-options">16 Options</a>
<ul>
<li><a href="Options.html#161-specifying-options">16.1 Specifying Options</a></li>
<li><a href="Options.html#162-description-of-options">16.2 Description of Options</a>
<ul>
<li><a href="Options.html#1621-changing-directories">16.2.1 Changing Directories</a></li>
<li><a href="Options.html#1622-completion">16.2.2 Completion</a></li>
<li><a href="Options.html#1623-expansion-and-globbing">16.2.3 Expansion and Globbing</a></li>
<li><a href="Options.html#1624-history">16.2.4 History</a></li>
<li><a href="Options.html#1625-initialisation">16.2.5 Initialisation</a></li>
<li><a href="Options.html#1626-inputoutput">16.2.6 Input/Output</a></li>
<li><a href="Options.html#1627-job-control">16.2.7 Job Control</a></li>
<li><a href="Options.html#1628-prompting">16.2.8 Prompting</a></li>
<li><a href="Options.html#1629-scripts-and-functions">16.2.9 Scripts and Functions</a></li>
<li><a href="Options.html#16210-shell-emulation">16.2.10 Shell Emulation</a></li>
<li><a href="Options.html#16211-shell-state">16.2.11 Shell State</a></li>
<li><a href="Options.html#16212-zle">16.2.12 Zle</a></li>
</ul>
</li>
<li><a href="Options.html#163-option-aliases">16.3 Option Aliases</a></li>
<li><a href="Options.html#164-single-letter-options">16.4 Single Letter Options</a>
<ul>
<li><a href="Options.html#1641-default-set">16.4.1 Default set</a></li>
<li><a href="Options.html#1642-shksh-emulation-set">16.4.2 sh/ksh emulation set</a></li>
<li><a href="Options.html#1643-also-note">16.4.3 Also note</a></li>
</ul>
</li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Options"></span> <span id="Options-1"></span></p>
<h1 id="16-options"><a class="header" href="#16-options">16 Options</a></h1>
<p><span id="index-options"></span></p>
<hr />
<p><span id="Specifying-Options"></span>
<span id="Specifying-Options-1"></span></p>
<h2 id="161-specifying-options"><a class="header" href="#161-specifying-options">16.1 Specifying Options</a></h2>
<p><span id="index-options_002c-specifying"></span></p>
<p>Options are primarily referred to by name. These names are case
insensitive and underscores are ignored. For example, ‘<code>allexport</code>’ is
equivalent to ‘<code>A__lleXP_ort</code>’.</p>
<p>The sense of an option name may be inverted by preceding it with ‘<code>no</code>’,
so ‘<code>setopt No_Beep</code>’ is equivalent to ‘<code>unsetopt beep</code>’. This inversion
can only be done once, so ‘<code>nonobeep</code>’ is <em>not</em> a synonym for ‘<code>beep</code>’.
Similarly, ‘<code>tify</code>’ is not a synonym for ‘<code>nonotify</code>’ (the inversion of
‘<code>notify</code>’).</p>
<p>Some options also have one or more single letter names. There are two
sets of single letter options: one used by default, and another used to
emulate sh/ksh (used when the <code>SH_OPTION_LETTERS</code> option is set). The
single letter options can be used on the shell command line, or with the
<code>set</code>, <code>setopt</code> and <code>unsetopt</code> builtins, as normal Unix options preceded
by ‘<code>-</code>’.</p>
<p>The sense of the single letter options may be inverted by using ‘<code>+</code>’
instead of ‘<code>-</code>’. Some of the single letter option names refer to an
option being off, in which case the inversion of that name refers to the
option being on. For example, ‘<code>+n</code>’ is the short name of ‘<code>exec</code>’, and
‘<code>-n</code>’ is the short name of its inversion, ‘<code>noexec</code>’.</p>
<p>In strings of single letter options supplied to the shell at startup,
trailing whitespace will be ignored; for example the string ‘<code>-f </code>’
will be treated just as ‘<code>-f</code>’, but the string ‘<code>-f i</code>’ is an error.
This is because many systems which implement the ‘<code>#!</code>’ mechanism for
calling scripts do not strip trailing whitespace.</p>
<hr />
<p><span id="Description-of-Options"></span>
<span id="Description-of-Options-1"></span></p>
<h2 id="162-description-of-options"><a class="header" href="#162-description-of-options">16.2 Description of Options</a></h2>
<p><span id="index-options_002c-description"></span></p>
<p>In the following list, options set by default in all emulations are
marked &lt;D&gt;; those set by default only in csh, ksh, sh, or zsh
emulations are marked &lt;C&gt;, &lt;K&gt;, &lt;S&gt;, &lt;Z&gt; as appropriate. When
listing options (by ‘<code>setopt</code>’, ‘<code>unsetopt</code>’, ‘<code>set -o</code>’ or ‘<code>set +o</code>’),
those turned on by default appear in the list prefixed with ‘<code>no</code>’.
Hence (unless <code>KSH_OPTION_PRINT</code> is set), ‘<code>setopt</code>’ shows all options
whose settings are changed from the default.</p>
<hr />
<p><span id="Changing-Directories"></span></p>
<h3 id="1621-changing-directories"><a class="header" href="#1621-changing-directories">16.2.1 Changing Directories</a></h3>
<p><span id="index-AUTO_005fCD"></span>
<span id="index-NO_005fAUTO_005fCD"></span>
<span id="index-AUTOCD"></span> <span id="index-NOAUTOCD"></span>
<span id="index-cd_002c-automatic"></span></p>
<p><code>AUTO_CD</code> (<code>-J</code>)</p>
<p>If a command is issued that can’t be executed as a normal command, and
the command is the name of a directory, perform the <code>cd</code> command to that
directory. This option is only applicable if the option <code>SHIN_STDIN</code> is
set, i.e. if commands are being read from standard input. The option is
designed for interactive use; it is recommended that <code>cd</code> be used
explicitly in scripts to avoid ambiguity.</p>
<p><span id="index-AUTO_005fPUSHD"></span>
<span id="index-NO_005fAUTO_005fPUSHD"></span>
<span id="index-AUTOPUSHD"></span> <span id="index-NOAUTOPUSHD"></span>
<span id="index-cd_002c-behaving-like-pushd"></span>
<span id="index-pushd_002c-making-cd-behave-like"></span></p>
<p><code>AUTO_PUSHD</code> (<code>-N</code>)</p>
<p>Make <code>cd</code> push the old directory onto the directory stack.</p>
<p><span id="index-CDABLE_005fVARS"></span>
<span id="index-NO_005fCDABLE_005fVARS"></span>
<span id="index-CDABLEVARS"></span>
<span id="index-NOCDABLEVARS"></span>
<span id="index-cd_002c-to-parameter"></span></p>
<p><code>CDABLE_VARS</code> (<code>-T</code>)</p>
<p>If the argument to a <code>cd</code> command (or an implied <code>cd</code> with the <code>AUTO_CD</code>
option set) is not a directory, and does not begin with a slash, try to
expand the expression as if it were preceded by a ‘<code>~</code>’ (see <a href="Expansion.html#Filename-Expansion">Filename
Expansion</a>).</p>
<p><span id="index-CD_005fSILENT"></span>
<span id="index-NO_005fCD_005fSILENT"></span>
<span id="index-CDSILENT"></span> <span id="index-NOCDSILENT"></span>
<span id="index-cd_002c-silencing"></span>
<span id="index-autocd_002c-silencing"></span></p>
<p><code>CD_SILENT</code></p>
<p>Never print the working directory after a <code>cd</code> (whether explicit or
implied with the <code>AUTO_CD</code> option set). <code>cd</code> normally prints the working
directory when the argument given to it was <code>-</code>, a stack entry, or the
name of a directory found under <code>CDPATH</code>. Note that this is distinct
from <code>pushd</code>’s stack-printing behaviour, which is controlled by
<code>PUSHD_SILENT</code>. This option overrides the printing-related effects of
<code>POSIX_CD</code>.</p>
<p><span id="index-CHASE_005fDOTS"></span>
<span id="index-NO_005fCHASE_005fDOTS"></span>
<span id="index-CHASEDOTS"></span> <span id="index-NOCHASEDOTS"></span>
<span id="index-cd_002c-with-_002e_002e-in-argument"></span></p>
<p><code>CHASE_DOTS</code></p>
<p>When changing to a directory containing a path segment ‘<code>..</code>’ which
would otherwise be treated as canceling the previous segment in the path
(in other words, ‘<code>foo/..</code>’ would be removed from the path, or if ‘<code>..</code>’
is the first part of the path, the last part of the current working
directory would be removed), instead resolve the path to the physical
directory. This option is overridden by <code>CHASE_LINKS</code>.</p>
<p>For example, suppose <code>/foo/bar</code> is a link to the directory <code>/alt/rod</code>.
Without this option set, ‘<code>cd /foo/bar/..</code>’ changes to <code>/foo</code>; with it
set, it changes to <code>/alt</code>. The same applies if the current directory is
<code>/foo/bar</code> and ‘<code>cd ..</code>’ is used. Note that all other symbolic links in
the path will also be resolved.</p>
<p><span id="index-CHASE_005fLINKS"></span>
<span id="index-NO_005fCHASE_005fLINKS"></span>
<span id="index-CHASELINKS"></span>
<span id="index-NOCHASELINKS"></span>
<span id="index-links_002c-symbolic"></span>
<span id="index-symbolic-links"></span></p>
<p><code>CHASE_LINKS</code> (<code>-w</code>)</p>
<p>Resolve symbolic links to their true values when changing directory.
This also has the effect of <code>CHASE_DOTS</code>, i.e. a ‘<code>..</code>’ path segment
will be treated as referring to the physical parent, even if the
preceding path segment is a symbolic link.</p>
<p><span id="index-POSIX_005fCD"></span> <span id="index-POSIXCD"></span>
<span id="index-NO_005fPOSIX_005fCD"></span>
<span id="index-NOPOSIXCD"></span>
<span id="index-CDPATH_002c-order-of-checking"></span></p>
<p><code>POSIX_CD</code> &lt;K&gt; &lt;S&gt;</p>
<p>Modifies the behaviour of <code>cd</code>, <code>chdir</code> and <code>pushd</code> commands to make
them more compatible with the POSIX standard. The behaviour with the
option unset is described in the documentation for the <code>cd</code> builtin in
<a href="Shell-Builtin-Commands.html#Shell-Builtin-Commands">Shell Builtin
Commands</a>. If the
option is set, the shell does not test for directories beneath the local
directory (‘<code>.</code>’) until after all directories in <code>cdpath</code> have been
tested, and the <code>cd</code> and <code>chdir</code> commands do not recognise arguments of
the form ‘{<code>+</code>|<code>-</code>}<code>n</code>’ as directory stack entries.</p>
<p>Also, if the option is set, the conditions under which the shell prints
the new directory after changing to it are modified. It is no longer
restricted to interactive shells (although printing of the directory
stack with <code>pushd</code> is still limited to interactive shells); and any use
of a component of <code>CDPATH</code>, including a ‘<code>.</code>’ but excluding an empty
component that is otherwise treated as ‘<code>.</code>’, causes the directory to be
printed.</p>
<p><span id="index-PUSHD_005fIGNORE_005fDUPS"></span>
<span id="index-NO_005fPUSHD_005fIGNORE_005fDUPS"></span>
<span id="index-PUSHDIGNOREDUPS"></span>
<span id="index-NOPUSHDIGNOREDUPS"></span>
<span id="index-directory-stack_002c-ignoring-duplicates"></span></p>
<p><code>PUSHD_IGNORE_DUPS</code></p>
<p>Don’t push multiple copies of the same directory onto the directory
stack.</p>
<p><span id="index-PUSHD_005fMINUS"></span>
<span id="index-NO_005fPUSHD_005fMINUS"></span>
<span id="index-PUSHDMINUS"></span>
<span id="index-NOPUSHDMINUS"></span>
<span id="index-directory-stack_002c-controlling-syntax"></span></p>
<p><code>PUSHD_MINUS</code></p>
<p>Exchanges the meanings of ‘<code>+</code>’ and ‘<code>-</code>’ when used with a number to
specify a directory in the stack.</p>
<p><span id="index-PUSHD_005fSILENT"></span>
<span id="index-NO_005fPUSHD_005fSILENT"></span>
<span id="index-PUSHDSILENT"></span>
<span id="index-NOPUSHDSILENT"></span>
<span id="index-directory-stack_002c-silencing"></span></p>
<p><code>PUSHD_SILENT</code> (<code>-E</code>)</p>
<p>Do not print the directory stack after <code>pushd</code> or <code>popd</code>.</p>
<p><span id="index-PUSHD_005fTO_005fHOME"></span>
<span id="index-NO_005fPUSHD_005fTO_005fHOME"></span>
<span id="index-PUSHDTOHOME"></span>
<span id="index-NOPUSHDTOHOME"></span>
<span id="index-pushd_002c-to-home"></span></p>
<p><code>PUSHD_TO_HOME</code> (<code>-D</code>)</p>
<p>Have <code>pushd</code> with no arguments act like ‘<code>pushd $HOME</code>’.</p>
<hr />
<p><span id="Completion-4"></span></p>
<h3 id="1622-completion"><a class="header" href="#1622-completion">16.2.2 Completion</a></h3>
<p><span id="index-ALWAYS_005fLAST_005fPROMPT"></span>
<span id="index-NO_005fALWAYS_005fLAST_005fPROMPT"></span>
<span id="index-ALWAYSLASTPROMPT"></span>
<span id="index-NOALWAYSLASTPROMPT"></span></p>
<p><code>ALWAYS_LAST_PROMPT</code> &lt;D&gt;</p>
<p>If unset, key functions that list completions try to return to the last
prompt if given a numeric argument. If set these functions try to return
to the last prompt if given <em>no</em> numeric argument.</p>
<p><span id="index-ALWAYS_005fTO_005fEND"></span>
<span id="index-NO_005fALWAYS_005fTO_005fEND"></span>
<span id="index-ALWAYSTOEND"></span>
<span id="index-NOALWAYSTOEND"></span></p>
<p><code>ALWAYS_TO_END</code></p>
<p>If a completion is performed with the cursor within a word, and a full
completion is inserted, the cursor is moved to the end of the word. That
is, the cursor is moved to the end of the word if either a single match
is inserted or menu completion is performed.</p>
<p><span id="index-AUTO_005fLIST"></span>
<span id="index-NO_005fAUTO_005fLIST"></span>
<span id="index-AUTOLIST"></span> <span id="index-NOAUTOLIST"></span>
<span id="index-completion_002c-listing-choices"></span></p>
<p><code>AUTO_LIST</code> (<code>-9</code>) &lt;D&gt;</p>
<p>Automatically list choices on an ambiguous completion.</p>
<p><span id="index-AUTO_005fMENU"></span>
<span id="index-NO_005fAUTO_005fMENU"></span>
<span id="index-AUTOMENU"></span> <span id="index-NOAUTOMENU"></span>
<span id="index-completion_002c-menu"></span></p>
<p><code>AUTO_MENU</code> &lt;D&gt;</p>
<p>Automatically use menu completion after the second consecutive request
for completion, for example by pressing the tab key repeatedly. This
option is overridden by <code>MENU_COMPLETE</code>.</p>
<p><span id="index-AUTO_005fNAME_005fDIRS"></span>
<span id="index-NO_005fAUTO_005fNAME_005fDIRS"></span>
<span id="index-AUTONAMEDIRS"></span>
<span id="index-NOAUTONAMEDIRS"></span>
<span id="index-directories_002c-named"></span></p>
<p><code>AUTO_NAME_DIRS</code></p>
<p>Any parameter that is set to the absolute name of a directory
immediately becomes a name for that directory, that will be used by the
‘<code>%~</code>’ and related prompt sequences, and will be available when
completion is performed on a word starting with ‘<code>~</code>’. (Otherwise, the
parameter must be used in the form ‘<code>~``param</code>’ first.)</p>
<p><span id="index-AUTO_005fPARAM_005fKEYS"></span>
<span id="index-NO_005fAUTO_005fPARAM_005fKEYS"></span>
<span id="index-AUTOPARAMKEYS"></span>
<span id="index-NOAUTOPARAMKEYS"></span></p>
<p><code>AUTO_PARAM_KEYS</code> &lt;D&gt;</p>
<p>If a parameter name was completed and a following character (normally a
space) automatically inserted, and the next character typed is one of
those that have to come directly after the name (like ‘<code>}</code>’, ‘<code>:</code>’,
etc.), the automatically added character is deleted, so that the
character typed comes immediately after the parameter name. Completion
in a brace expansion is affected similarly: the added character is a
‘<code>,</code>’, which will be removed if ‘<code>}</code>’ is typed next.</p>
<p><span id="index-AUTO_005fPARAM_005fSLASH"></span>
<span id="index-NO_005fAUTO_005fPARAM_005fSLASH"></span>
<span id="index-AUTOPARAMSLASH"></span>
<span id="index-NOAUTOPARAMSLASH"></span></p>
<p><code>AUTO_PARAM_SLASH</code> &lt;D&gt;</p>
<p>If a parameter is completed whose content is the name of a directory,
then add a trailing slash instead of a space.</p>
<p><span id="index-AUTO_005fREMOVE_005fSLASH"></span>
<span id="index-NO_005fAUTO_005fREMOVE_005fSLASH"></span>
<span id="index-AUTOREMOVESLASH"></span>
<span id="index-NOAUTOREMOVESLASH"></span>
<span id="index-slash_002c-removing-trailing"></span></p>
<p><code>AUTO_REMOVE_SLASH</code> &lt;D&gt;</p>
<p>When the last character resulting from a completion is a slash and the
next character typed is a word delimiter, a slash, or a character that
ends a command (such as a semicolon or an ampersand), remove the slash.</p>
<p><span id="index-BASH_005fAUTO_005fLIST"></span>
<span id="index-NO_005fBASH_005fAUTO_005fLIST"></span>
<span id="index-BASHAUTOLIST"></span>
<span id="index-NOBASHAUTOLIST"></span>
<span id="index-completion_002c-listing-choices_002c-bash-style"></span></p>
<p><code>BASH_AUTO_LIST</code></p>
<p>On an ambiguous completion, automatically list choices when the
completion function is called twice in succession. This takes precedence
over <code>AUTO_LIST</code>. The setting of <code>LIST_AMBIGUOUS</code> is respected. If
<code>AUTO_MENU</code> is set, the menu behaviour will then start with the third
press. Note that this will not work with <code>MENU_COMPLETE</code>, since repeated
completion calls immediately cycle through the list in that case.</p>
<p><span id="index-COMPLETE_005fALIASES"></span>
<span id="index-NO_005fCOMPLETE_005fALIASES"></span>
<span id="index-COMPLETEALIASES"></span>
<span id="index-NOCOMPLETEALIASES"></span>
<span id="index-aliases_002c-completion-of"></span></p>
<p><code>COMPLETE_ALIASES</code></p>
<p>Prevents aliases on the command line from being internally substituted
before completion is attempted. The effect is to make the alias a
distinct command for completion purposes.</p>
<p><span id="index-COMPLETE_005fIN_005fWORD"></span>
<span id="index-NO_005fCOMPLETE_005fIN_005fWORD"></span>
<span id="index-COMPLETEINWORD"></span>
<span id="index-NOCOMPLETEINWORD"></span></p>
<p><code>COMPLETE_IN_WORD</code></p>
<p>If unset, the cursor is set to the end of the word if completion is
started. Otherwise it stays there and completion is done from both ends.</p>
<p><span id="index-GLOB_005fCOMPLETE"></span>
<span id="index-NO_005fGLOB_005fCOMPLETE"></span>
<span id="index-GLOBCOMPLETE"></span>
<span id="index-NOGLOBCOMPLETE"></span></p>
<p><code>GLOB_COMPLETE</code></p>
<p>When the current word has a glob pattern, do not insert all the words
resulting from the expansion but generate matches as for completion and
cycle through them like <code>MENU_COMPLETE</code>. The matches are generated as if
a ‘<code>*</code>’ was added to the end of the word, or inserted at the cursor when
<code>COMPLETE_IN_WORD</code> is set. This actually uses pattern matching, not
globbing, so it works not only for files but for any completion, such as
options, user names, etc.</p>
<p>Note that when the pattern matcher is used, matching control (for
example, case-insensitive or anchored matching) cannot be used. This
limitation only applies when the current word contains a pattern; simply
turning on the <code>GLOB_COMPLETE</code> option does not have this effect.</p>
<p><span id="index-HASH_005fLIST_005fALL"></span>
<span id="index-NO_005fHASH_005fLIST_005fALL"></span>
<span id="index-HASHLISTALL"></span>
<span id="index-NOHASHLISTALL"></span></p>
<p><code>HASH_LIST_ALL</code> &lt;D&gt;</p>
<p>Whenever a command completion or spelling correction is attempted, make
sure the entire command path is hashed first. This makes the first
completion slower but avoids false reports of spelling errors.</p>
<p><span id="index-LIST_005fAMBIGUOUS"></span>
<span id="index-NO_005fLIST_005fAMBIGUOUS"></span>
<span id="index-LISTAMBIGUOUS"></span>
<span id="index-NOLISTAMBIGUOUS"></span>
<span id="index-ambiguous-completion"></span>
<span id="index-completion_002c-ambiguous"></span></p>
<p><code>LIST_AMBIGUOUS</code> &lt;D&gt;</p>
<p>This option works when <code>AUTO_LIST</code> or <code>BASH_AUTO_LIST</code> is also set. If
there is an unambiguous prefix to insert on the command line, that is
done without a completion list being displayed; in other words,
auto-listing behaviour only takes place when nothing would be inserted.
In the case of <code>BASH_AUTO_LIST</code>, this means that the list will be
delayed to the third call of the function.</p>
<p><span id="index-LIST_005fBEEP"></span>
<span id="index-NO_005fLIST_005fBEEP"></span>
<span id="index-LISTBEEP"></span> <span id="index-NOLISTBEEP"></span>
<span id="index-beep_002c-ambiguous-completion"></span>
<span id="index-completion_002c-beep-on-ambiguous"></span></p>
<p><code>LIST_BEEP</code> &lt;D&gt;</p>
<p>Beep on an ambiguous completion. More accurately, this forces the
completion widgets to return status 1 on an ambiguous completion, which
causes the shell to beep if the option <code>BEEP</code> is also set; this may be
modified if completion is called from a user-defined widget.</p>
<p><span id="index-LIST_005fPACKED"></span>
<span id="index-NO_005fLIST_005fPACKED"></span>
<span id="index-LISTPACKED"></span>
<span id="index-NOLISTPACKED"></span>
<span id="index-completion_002c-listing"></span></p>
<p><code>LIST_PACKED</code></p>
<p>Try to make the completion list smaller (occupying less lines) by
printing the matches in columns with different widths.</p>
<p><span id="index-LIST_005fROWS_005fFIRST"></span>
<span id="index-NO_005fLIST_005fROWS_005fFIRST"></span>
<span id="index-LISTROWSFIRST"></span>
<span id="index-NOLISTROWSFIRST"></span>
<span id="index-completion_002c-listing-order"></span></p>
<p><code>LIST_ROWS_FIRST</code></p>
<p>Lay out the matches in completion lists sorted horizontally, that is,
the second match is to the right of the first one, not under it as
usual.</p>
<p><span id="index-LIST_005fTYPES"></span>
<span id="index-NO_005fLIST_005fTYPES"></span>
<span id="index-LISTTYPES"></span> <span id="index-NOLISTTYPES"></span>
<span id="index-marking-file-types"></span>
<span id="index-files_002c-marking-type-of"></span></p>
<p><code>LIST_TYPES</code> (<code>-X</code>) &lt;D&gt;</p>
<p>When listing files that are possible completions, show the type of each
file with a trailing identifying mark.</p>
<p><span id="index-MENU_005fCOMPLETE"></span>
<span id="index-NO_005fMENU_005fCOMPLETE"></span>
<span id="index-MENUCOMPLETE"></span>
<span id="index-NOMENUCOMPLETE"></span>
<span id="index-completion_002c-menu-1"></span></p>
<p><code>MENU_COMPLETE</code> (<code>-Y</code>)</p>
<p>On an ambiguous completion, instead of listing possibilities or beeping,
insert the first match immediately. Then when completion is requested
again, remove the first match and insert the second match, etc. When
there are no more matches, go back to the first one again.
<code>reverse-menu-complete</code> may be used to loop through the list in the
other direction. This option overrides <code>AUTO_MENU</code>.</p>
<p><span id="index-REC_005fEXACT"></span>
<span id="index-NO_005fREC_005fEXACT"></span>
<span id="index-RECEXACT"></span> <span id="index-NORECEXACT"></span>
<span id="index-completion_002c-exact-matches"></span></p>
<p><code>REC_EXACT</code> (<code>-S</code>)</p>
<p>If the string on the command line exactly matches one of the possible
completions, it is accepted, even if there is another completion (i.e.
that string with something else added) that also matches.</p>
<hr />
<p><span id="Expansion-and-Globbing"></span></p>
<h3 id="1623-expansion-and-globbing"><a class="header" href="#1623-expansion-and-globbing">16.2.3 Expansion and Globbing</a></h3>
<p><span id="index-BAD_005fPATTERN"></span>
<span id="index-NO_005fBAD_005fPATTERN"></span>
<span id="index-BADPATTERN"></span>
<span id="index-NOBADPATTERN"></span>
<span id="index-globbing_002c-bad-pattern"></span>
<span id="index-filename-generation_002c-bad-pattern"></span></p>
<p><code>BAD_PATTERN</code> (<code>+2</code>) &lt;C&gt; &lt;Z&gt;</p>
<p>If a pattern for filename generation is badly formed, print an error
message. (If this option is unset, the pattern will be left unchanged.)</p>
<p><span id="index-BARE_005fGLOB_005fQUAL"></span>
<span id="index-NO_005fBARE_005fGLOB_005fQUAL"></span>
<span id="index-BAREGLOBQUAL"></span>
<span id="index-NOBAREGLOBQUAL"></span>
<span id="index-globbing-qualifiers_002c-enable"></span>
<span id="index-enable-globbing-qualifiers"></span></p>
<p><code>BARE_GLOB_QUAL</code> &lt;Z&gt;</p>
<p>In a glob pattern, treat a trailing set of parentheses as a qualifier
list, if it contains no ‘<code>|</code>’, ‘<code>(</code>’ or (if special) ‘<code>~</code>’ characters.
See <a href="Expansion.html#Filename-Generation">Filename Generation</a>.</p>
<p><span id="index-BRACE_005fCCL"></span>
<span id="index-NO_005fBRACE_005fCCL"></span>
<span id="index-BRACECCL"></span> <span id="index-NOBRACECCL"></span>
<span id="index-brace-expansion_002c-extending"></span>
<span id="index-expansion_002c-brace_002c-extending"></span></p>
<p><code>BRACE_CCL</code></p>
<p>Expand expressions in braces which would not otherwise undergo brace
expansion to a lexically ordered list of all the characters. See <a href="Expansion.html#Brace-Expansion">Brace
Expansion</a>.</p>
<p><span id="index-CASE_005fGLOB"></span>
<span id="index-NO_005fCASE_005fGLOB"></span>
<span id="index-CASEGLOB"></span> <span id="index-NOCASEGLOB"></span>
<span id="index-case_002dinsensitive-globbing_002c-option"></span></p>
<p><code>CASE_GLOB</code> &lt;D&gt;</p>
<p>Make globbing (filename generation) sensitive to case. Note that other
uses of patterns are always sensitive to case. If the option is unset,
the presence of any character which is special to filename generation
will cause case-insensitive matching. For example, <code>cvs(/)</code> can match
the directory <code>CVS</code> owing to the presence of the globbing flag (unless
the option <code>BARE_GLOB_QUAL</code> is unset).</p>
<p><span id="index-CASE_005fMATCH"></span>
<span id="index-NO_005fCASE_005fMATCH"></span>
<span id="index-CASEMATCH"></span> <span id="index-NOCASEMATCH"></span>
<span id="index-case_002dinsensitive-regular-expression-matches_002c-option"></span>
<span id="index-regular-expressions_002c-case_002dinsensitive-matching_002c-option"></span></p>
<p><code>CASE_MATCH</code> &lt;D&gt;</p>
<p>Make regular expressions using the <code>zsh/regex</code> module (including matches
with <code>=~</code>) sensitive to case.</p>
<p><span id="index-CSH_005fNULL_005fGLOB"></span>
<span id="index-NO_005fCSH_005fNULL_005fGLOB"></span>
<span id="index-CSHNULLGLOB"></span>
<span id="index-NOCSHNULLGLOB"></span>
<span id="index-csh_002c-null-globbing-style"></span>
<span id="index-null-globbing-style_002c-csh"></span>
<span id="index-globbing_002c-null_002c-style_002c-csh"></span></p>
<p><code>CSH_NULL_GLOB</code> &lt;C&gt;</p>
<p>If a pattern for filename generation has no matches, delete the pattern
from the argument list; do not report an error unless all the patterns
in a command have no matches. Overrides <code>NOMATCH</code>.</p>
<p><span id="index-EQUALS"></span> <span id="index-NO_005fEQUALS"></span>
<span id="index-NOEQUALS"></span>
<span id="index-filename-expansion_002c-_003d"></span></p>
<p><code>EQUALS</code> &lt;Z&gt;</p>
<p>Perform <code>=</code> filename expansion. (See <a href="Expansion.html#Filename-Expansion">Filename
Expansion</a>.)</p>
<p><span id="index-EXTENDED_005fGLOB"></span>
<span id="index-NO_005fEXTENDED_005fGLOB"></span>
<span id="index-EXTENDEDGLOB"></span>
<span id="index-NOEXTENDEDGLOB"></span>
<span id="index-globbing_002c-extended"></span></p>
<p><code>EXTENDED_GLOB</code></p>
<p>Treat the ‘<code>#</code>’, ‘<code>~</code>’ and ‘<code>^</code>’ characters as part of patterns for
filename generation, etc. (An initial unquoted ‘<code>~</code>’ always produces
named directory expansion.)</p>
<p><span id="index-FORCE_005fFLOAT"></span>
<span id="index-NO_005fFORCE_005fFLOAT"></span>
<span id="index-FORCEFLOAT"></span>
<span id="index-NOFORCEFLOAT"></span>
<span id="index-floating-point_002c-forcing-use-of"></span>
<span id="index-forcing-use-of-floating-point"></span></p>
<p><code>FORCE_FLOAT</code></p>
<p>Constants in arithmetic evaluation will be treated as floating point
even without the use of a decimal point; the values of integer variables
will be converted to floating point when used in arithmetic expressions.
Integers in any base will be converted.</p>
<p><span id="index-GLOB"></span> <span id="index-NO_005fGLOB"></span>
<span id="index-NOGLOB"></span>
<span id="index-globbing_002c-enabling"></span>
<span id="index-enabling-globbing"></span></p>
<p><code>GLOB</code> (<code>+F</code>, ksh: <code>+f</code>) &lt;D&gt;</p>
<p>Perform filename generation (globbing). (See <a href="Expansion.html#Filename-Generation">Filename
Generation</a>.)</p>
<p><span id="index-GLOB_005fASSIGN"></span>
<span id="index-NO_005fGLOB_005fASSIGN"></span>
<span id="index-GLOBASSIGN"></span>
<span id="index-NOGLOBASSIGN"></span></p>
<p><code>GLOB_ASSIGN</code> &lt;C&gt;</p>
<p>If this option is set, filename generation (globbing) is performed on
the right hand side of scalar parameter assignments of the form
‘<code>name``=``pattern</code> (e.g. ‘<code>foo=*</code>’). If the result has more than one
word the parameter will become an array with those words as arguments.
This option is provided for backwards compatibility only: globbing is
always performed on the right hand side of array assignments of the form
‘<code>name``=(``value``)</code>’ (e.g. ‘<code>foo=(*)</code>’) and this form is recommended
for clarity; with this option set, it is not possible to predict whether
the result will be an array or a scalar.</p>
<p><span id="index-GLOB_005fDOTS"></span>
<span id="index-NO_005fGLOB_005fDOTS"></span>
<span id="index-GLOBDOTS"></span> <span id="index-NOGLOBDOTS"></span>
<span id="index-globbing_002c-of-_002e-files"></span></p>
<p><code>GLOB_DOTS</code> (<code>-4</code>)</p>
<p>Do not require a leading ‘<code>.</code>’ in a filename to be matched explicitly.</p>
<p><span id="index-GLOB_005fSTAR_005fSHORT"></span>
<span id="index-NO_005fGLOB_005fSTAR_005fSHORT"></span>
<span id="index-GLOBSTARSHORT"></span>
<span id="index-NOGLOBSTARSHORT"></span>
<span id="index-globbing_002c-short-forms"></span>
<span id="index-globbing_002c-_002a_002a-special"></span></p>
<p><code>GLOB_STAR_SHORT</code></p>
<p>When this option is set and the default zsh-style globbing is in effect,
the pattern ‘<code>**/*</code>’ can be abbreviated to ‘<code>**</code>’ and the pattern
‘<code>***/*</code>’ can be abbreviated to <code>***</code>. Hence ‘<code>**.c</code>’ finds a file
ending in <code>.c</code> in any subdirectory, and ‘<code>***.c</code>’ does the same while
also following symbolic links. A <code>/</code> immediately after the ‘<code>**</code>’ or
‘<code>***</code>’ forces the pattern to be treated as the unabbreviated form.</p>
<p><span id="index-GLOB_005fSUBST"></span>
<span id="index-NO_005fGLOB_005fSUBST"></span>
<span id="index-GLOBSUBST"></span> <span id="index-NOGLOBSUBST"></span></p>
<p><code>GLOB_SUBST</code> &lt;C&gt; &lt;K&gt; &lt;S&gt;</p>
<p>Treat any characters resulting from parameter expansion as being
eligible for filename expansion and filename generation, and any
characters resulting from command substitution as being eligible for
filename generation. Braces (and commas in between) do not become
eligible for expansion.</p>
<p><span id="index-HIST_005fSUBST_005fPATTERN"></span>
<span id="index-NO_005fHIST_005fSUBST_005fPATTERN"></span>
<span id="index-HISTSUBSTPATTERN"></span>
<span id="index-NOHISTSUBSTPATTERN"></span></p>
<p><code>HIST_SUBST_PATTERN</code></p>
<p>Substitutions using the <code>:s</code> and <code>:&amp;</code> history modifiers are performed
with pattern matching instead of string matching. This occurs wherever
history modifiers are valid, including glob qualifiers and parameters.
See <a href="Expansion.html#Modifiers">Modifiers</a>.</p>
<p><span id="index-IGNORE_005fBRACES"></span>
<span id="index-NO_005fIGNORE_005fBRACES"></span>
<span id="index-IGNOREBRACES"></span>
<span id="index-NOIGNOREBRACES"></span>
<span id="index-disabling-brace-expansion"></span>
<span id="index-brace-expansion_002c-disabling"></span>
<span id="index-expansion_002c-brace_002c-disabling"></span></p>
<p><code>IGNORE_BRACES</code> (<code>-I</code>) &lt;S&gt;</p>
<p>Do not perform brace expansion. For historical reasons this also
includes the effect of the <code>IGNORE_CLOSE_BRACES</code> option.</p>
<p><span id="index-IGNORE_005fCLOSE_005fBRACES"></span>
<span id="index-NO_005fIGNORE_005fCLOSE_005fBRACES"></span>
<span id="index-IGNORECLOSEBRACES"></span>
<span id="index-NOIGNORECLOSEBRACES"></span></p>
<p><code>IGNORE_CLOSE_BRACES</code></p>
<p>When neither this option nor <code>IGNORE_BRACES</code> is set, a sole close brace
character ‘<code>}</code>’ is syntactically significant at any point on a command
line. This has the effect that no semicolon or newline is necessary
before the brace terminating a function or current shell construct. When
either option is set, a closing brace is syntactically significant only
in command position. Unlike <code>IGNORE_BRACES</code>, this option does not
disable brace expansion.</p>
<p>For example, with both options unset a function may be defined in the
following fashion:</p>
<div class="example">
<pre><code class="language-example">args() { echo $# }
</code></pre>
</div>
<p>while if either option is set, this does not work and something
equivalent to the following is required:</p>
<div class="example">
<pre><code class="language-example">args() { echo $#; }
</code></pre>
</div>
<p><span id="index-KSH_005fGLOB"></span>
<span id="index-NO_005fKSH_005fGLOB"></span>
<span id="index-KSHGLOB"></span> <span id="index-NOKSHGLOB"></span></p>
<p><code>KSH_GLOB</code> &lt;K&gt;</p>
<p>In pattern matching, the interpretation of parentheses is affected by a
preceding ‘<code>@</code>’, ‘<code>*</code>’, ‘<code>+</code>’, ‘<code>?</code>’ or ‘<code>!</code>’. See <a href="Expansion.html#Filename-Generation">Filename
Generation</a>.</p>
<p><span id="index-MAGIC_005fEQUAL_005fSUBST"></span>
<span id="index-NO_005fMAGIC_005fEQUAL_005fSUBST"></span>
<span id="index-MAGICEQUALSUBST"></span>
<span id="index-NOMAGICEQUALSUBST"></span></p>
<p><code>MAGIC_EQUAL_SUBST</code></p>
<p>All unquoted arguments of the form ‘<code>anything``=``expression</code>’ appearing
after the command name have filename expansion (that is, where
<code>expression</code> has a leading ‘<code>~</code>’ or ‘<code>=</code>’) performed on <code>expression</code> as
if it were a parameter assignment. The argument is not otherwise treated
specially; it is passed to the command as a single argument, and not
used as an actual parameter assignment. For example, in <code>echo foo=~/bar:~/rod</code>, both occurrences of <code>~</code> would be replaced. Note that
this happens anyway with <code>typeset</code> and similar statements.</p>
<p>This option respects the setting of the <code>KSH_TYPESET</code> option. In other
words, if both options are in effect, arguments looking like assignments
will not undergo word splitting.</p>
<p><span id="index-MARK_005fDIRS"></span>
<span id="index-NO_005fMARK_005fDIRS"></span>
<span id="index-MARKDIRS"></span> <span id="index-NOMARKDIRS"></span>
<span id="index-directories_002c-marking"></span>
<span id="index-marking-directories"></span></p>
<p><code>MARK_DIRS</code> (<code>-8</code>, ksh: <code>-X</code>)</p>
<p>Append a trailing ‘<code>/</code>’ to all directory names resulting from filename
generation (globbing).</p>
<p><span id="index-MULTIBYTE"></span>
<span id="index-NO_005fMULTIBYTE"></span>
<span id="index-NOMULTIBYTE"></span>
<span id="index-characters_002c-multibyte_002c-in-expansion-and-globbing"></span>
<span id="index-multibyte-characters_002c-in-expansion-and-globbing"></span></p>
<p><code>MULTIBYTE</code> &lt;D&gt;</p>
<p>Respect multibyte characters when found in strings. When this option is
set, strings are examined using the system library to determine how many
bytes form a character, depending on the current locale. This affects
the way characters are counted in pattern matching, parameter values and
various delimiters.</p>
<p>The option is on by default if the shell was compiled with
<code>MULTIBYTE_SUPPORT</code>; otherwise it is off by default and has no effect if
turned on.</p>
<p>If the option is off a single byte is always treated as a single
character. This setting is designed purely for examining strings known
to contain raw bytes or other values that may not be characters in the
current locale. It is not necessary to unset the option merely because
the character set for the current locale does not contain multibyte
characters.</p>
<p>The option does not affect the shell’s editor, which always uses the
locale to determine multibyte characters. This is because the character
set displayed by the terminal emulator is independent of shell settings.</p>
<p><span id="index-NOMATCH"></span> <span id="index-NO_005fNOMATCH"></span>
<span id="index-NONOMATCH"></span>
<span id="index-globbing_002c-no-matches"></span></p>
<p><code>NOMATCH</code> (<code>+3</code>) &lt;C&gt; &lt;Z&gt;</p>
<p>If a pattern for filename generation has no matches, print an error,
instead of leaving it unchanged in the argument list. This also applies
to file expansion of an initial ‘<code>~</code>’ or ‘<code>=</code>’.</p>
<p><span id="index-NULL_005fGLOB"></span>
<span id="index-NO_005fNULL_005fGLOB"></span>
<span id="index-NULLGLOB"></span> <span id="index-NONULLGLOB"></span>
<span id="index-globbing_002c-no-matches-1"></span></p>
<p><code>NULL_GLOB</code> (<code>-G</code>)</p>
<p>If a pattern for filename generation has no matches, delete the pattern
from the argument list instead of reporting an error. Overrides
<code>NOMATCH</code>.</p>
<p><span id="index-NUMERIC_005fGLOB_005fSORT"></span>
<span id="index-NO_005fNUMERIC_005fGLOB_005fSORT"></span>
<span id="index-NUMERICGLOBSORT"></span>
<span id="index-NONUMERICGLOBSORT"></span>
<span id="index-globbing_002c-sorting-numerically"></span></p>
<p><code>NUMERIC_GLOB_SORT</code></p>
<p>If numeric filenames are matched by a filename generation pattern, sort
the filenames numerically rather than lexicographically.</p>
<p><span id="index-RC_005fEXPAND_005fPARAM"></span>
<span id="index-NO_005fRC_005fEXPAND_005fPARAM"></span>
<span id="index-RCEXPANDPARAM"></span>
<span id="index-NORCEXPANDPARAM"></span>
<span id="index-rc_002c-parameter-expansion-style"></span>
<span id="index-parameter-expansion-style_002c-rc"></span></p>
<p><code>RC_EXPAND_PARAM</code> (<code>-P</code>)</p>
<p>Array expansions of the form ‘<code>foo``${``xx``}``bar</code>’, where the
parameter <code>xx</code> is set to <code>(``a b c``)</code>, are substituted with ‘<code>fooabar foobbar foocbar</code>’ instead of the default ‘<code>fooa b cbar</code>’. Note that an
empty array will therefore cause all arguments to be removed.</p>
<p><span id="index-REMATCH_005fPCRE"></span>
<span id="index-NO_005fREMATCH_005fPCRE"></span>
<span id="index-REMATCHPCRE"></span>
<span id="index-NOREMATCHPCRE"></span>
<span id="index-regexp_002c-PCRE"></span>
<span id="index-PCRE_002c-regexp"></span></p>
<p><code>REMATCH_PCRE</code></p>
<p>If set, regular expression matching with the <code>=~</code> operator will use
Perl-Compatible Regular Expressions from the PCRE library. (The
<code>zsh/pcre</code> module must be available.) If not set, regular expressions
will use the extended regexp syntax provided by the system libraries.</p>
<p><span id="index-SH_005fGLOB"></span>
<span id="index-NO_005fSH_005fGLOB"></span>
<span id="index-SHGLOB"></span> <span id="index-NOSHGLOB"></span>
<span id="index-sh_002c-globbing-style"></span>
<span id="index-globbing-style_002c-sh"></span></p>
<p><code>SH_GLOB</code> &lt;K&gt; &lt;S&gt;</p>
<p>Disables the special meaning of ‘<code>(</code>’, ‘<code>|</code>’, ‘<code>)</code>’ and ’<code>&lt;</code>’ for
globbing the result of parameter and command substitutions, and in some
other places where the shell accepts patterns. If <code>SH_GLOB</code> is set but
<code>KSH_GLOB</code> is not, the shell allows the interpretation of subshell
expressions enclosed in parentheses in some cases where there is no
space before the opening parenthesis, e.g. <code>!(true)</code> is interpreted as
if there were a space after the <code>!</code>. This option is set by default if
zsh is invoked as <code>sh</code> or <code>ksh</code>.</p>
<p><span id="index-UNSET"></span> <span id="index-NO_005fUNSET"></span>
<span id="index-NOUNSET"></span>
<span id="index-parameters_002c-substituting-unset"></span>
<span id="index-unset-parameters_002c-substituting"></span></p>
<p><code>UNSET</code> (<code>+u</code>, ksh: <code>+u</code>) &lt;K&gt; &lt;S&gt; &lt;Z&gt;</p>
<p>Treat unset parameters as if they were empty when substituting, and as
if they were zero when reading their values in arithmetic expansion and
arithmetic commands. Otherwise they are treated as an error.</p>
<p><span id="index-WARN_005fCREATE_005fGLOBAL"></span>
<span id="index-NO_005fWARN_005fCREATE_005fGLOBAL"></span>
<span id="index-WARNCREATEGLOBAL"></span>
<span id="index-NOWARNCREATEGLOBAL"></span>
<span id="index-parameters_002c-warning-when-created-globally"></span></p>
<p><code>WARN_CREATE_GLOBAL</code></p>
<p>Print a warning message when a global parameter is created in a function
by an assignment or in math context. This often indicates that a
parameter has not been declared local when it should have been.
Parameters explicitly declared global from within a function using
<code>typeset -g</code> do not cause a warning. Note that there is no warning when
a local parameter is assigned to in a nested function, which may also
indicate an error.</p>
<p><span id="index-WARN_005fNESTED_005fVAR"></span>
<span id="index-NO_005fWARN_005fNESTED_005fVAR"></span>
<span id="index-WARNNESTEDVAR"></span>
<span id="index-NO_005fWARNNESTEDVAR"></span>
<span id="index-parameters_002c-warning-when-setting-in-enclosing-scope"></span></p>
<p><code>WARN_NESTED_VAR</code></p>
<p>Print a warning message when an existing parameter from an enclosing
function scope, or global, is set in a function by an assignment or in
math context. Assignment to shell special parameters does not cause a
warning. This is the companion to <code>WARN_CREATE_GLOBAL</code> as in this case
the warning is only printed when a parameter is <em>not</em> created. Where
possible, use of <code>typeset -g</code> to set the parameter suppresses the error,
but note that this needs to be used every time the parameter is set. To
restrict the effect of this option to a single function scope, use
‘<code>functions -W</code>’.</p>
<p>For example, the following code produces a warning for the assignment
inside the function <code>nested</code> as that overrides the value within
<code>toplevel</code></p>
<div class="example">
<pre><code class="language-example">toplevel() {
local foo=&quot;in fn&quot;
nested
}
nested() {
foo=&quot;in nested&quot;
}
setopt warn_nested_var
toplevel
</code></pre>
</div>
<hr />
<p><span id="History"></span></p>
<h3 id="1624-history"><a class="header" href="#1624-history">16.2.4 History</a></h3>
<p><span id="index-APPEND_005fHISTORY"></span>
<span id="index-NO_005fAPPEND_005fHISTORY"></span>
<span id="index-APPENDHISTORY"></span>
<span id="index-NOAPPENDHISTORY"></span>
<span id="index-history_002c-appending-to-a-file"></span></p>
<p><code>APPEND_HISTORY</code> &lt;D&gt;</p>
<p>If this is set, zsh sessions will append their history list to the
history file, rather than replace it. Thus, multiple parallel zsh
sessions will all have the new entries from their history lists added to
the history file, in the order that they exit. The file will still be
periodically re-written to trim it when the number of lines grows 20%
beyond the value specified by <code>$SAVEHIST</code> (see also the
<code>HIST_SAVE_BY_COPY</code> option).</p>
<p><span id="index-BANG_005fHIST"></span>
<span id="index-NO_005fBANG_005fHIST"></span>
<span id="index-BANGHIST"></span> <span id="index-NOBANGHIST"></span>
<span id="index-history_002c-enable-substitution"></span>
<span id="index-enable-history-substitution"></span></p>
<p><code>BANG_HIST</code> (<code>+K</code>) &lt;C&gt; &lt;Z&gt;</p>
<p>Perform textual history expansion, csh-style, treating the character
‘<code>!</code>’ specially.</p>
<p><span id="index-EXTENDED_005fHISTORY"></span>
<span id="index-NO_005fEXTENDED_005fHISTORY"></span>
<span id="index-EXTENDEDHISTORY"></span>
<span id="index-NOEXTENDEDHISTORY"></span>
<span id="index-history_002c-timestamping"></span></p>
<p><code>EXTENDED_HISTORY</code> &lt;C&gt;</p>
<p>Save each command’s beginning timestamp (in seconds since the epoch) and
the duration (in seconds) to the history file. The format of this
prefixed data is:</p>
<p>‘<code> : ``&lt;beginning time&gt;``:``&lt;elapsed seconds&gt;``;``&lt;command&gt;</code>’.</p>
<p><span id="index-HIST_005fALLOW_005fCLOBBER"></span>
<span id="index-NO_005fHIST_005fALLOW_005fCLOBBER"></span>
<span id="index-HISTALLOWCLOBBER"></span>
<span id="index-NOHISTALLOWCLOBBER"></span></p>
<p><code>HIST_ALLOW_CLOBBER</code></p>
<p>Add ‘<code>|</code>’ to output redirections in the history. This allows history
references to clobber files even when <code>CLOBBER</code> is unset.</p>
<p><span id="index-HIST_005fBEEP"></span>
<span id="index-NO_005fHIST_005fBEEP"></span>
<span id="index-HISTBEEP"></span> <span id="index-NOHISTBEEP"></span>
<span id="index-history-beeping"></span>
<span id="index-beep_002c-history"></span></p>
<p><code>HIST_BEEP</code> &lt;D&gt;</p>
<p>Beep in ZLE when a widget attempts to access a history entry which isn’t
there.</p>
<p><span id="index-HIST_005fEXPIRE_005fDUPS_005fFIRST"></span>
<span id="index-NO_005fHIST_005fEXPIRE_005fDUPS_005fFIRST"></span>
<span id="index-HISTEXPIREDUPSFIRST"></span>
<span id="index-NOHISTEXPIREDUPSFIRST"></span>
<span id="index-history_002c-expiring-duplicates"></span></p>
<p><code>HIST_EXPIRE_DUPS_FIRST</code></p>
<p>If the internal history needs to be trimmed to add the current command
line, setting this option will cause the oldest history event that has a
duplicate to be lost before losing a unique event from the list. You
should be sure to set the value of <code>HISTSIZE</code> to a larger number than
<code>SAVEHIST</code> in order to give you some room for the duplicated events,
otherwise this option will behave just like <code>HIST_IGNORE_ALL_DUPS</code> once
the history fills up with unique events.</p>
<p><span id="index-HIST_005fFCNTL_005fLOCK"></span>
<span id="index-NO_005fHIST_005fFCNTL_005fLOCK"></span>
<span id="index-HISTFCNTLLOCK"></span>
<span id="index-NOHISTFCNTLLOCK"></span></p>
<p><code>HIST_FCNTL_LOCK</code></p>
<p>When writing out the history file, by default zsh uses ad-hoc file
locking to avoid known problems with locking on some operating systems.
With this option locking is done by means of the system’s <code>fcntl</code> call,
where this method is available. On recent operating systems this may
provide better performance, in particular avoiding history corruption
when files are stored on NFS.</p>
<p><span id="index-HIST_005fFIND_005fNO_005fDUPS"></span>
<span id="index-NO_005fHIST_005fFIND_005fNO_005fDUPS"></span>
<span id="index-HISTFINDNODUPS"></span>
<span id="index-NOHISTFINDNODUPS"></span>
<span id="index-history_002c-ignoring-duplicates-in-search"></span></p>
<p><code>HIST_FIND_NO_DUPS</code></p>
<p>When searching for history entries in the line editor, do not display
duplicates of a line previously found, even if the duplicates are not
contiguous.</p>
<p><span id="index-HIST_005fIGNORE_005fALL_005fDUPS"></span>
<span id="index-NO_005fHIST_005fIGNORE_005fALL_005fDUPS"></span>
<span id="index-HISTIGNOREALLDUPS"></span>
<span id="index-NOHISTIGNOREALLDUPS"></span>
<span id="index-history_002c-ignoring-all-duplicates"></span></p>
<p><code>HIST_IGNORE_ALL_DUPS</code></p>
<p>If a new command line being added to the history list duplicates an
older one, the older command is removed from the list (even if it is not
the previous event).</p>
<p><span id="index-HIST_005fIGNORE_005fDUPS"></span>
<span id="index-NO_005fHIST_005fIGNORE_005fDUPS"></span>
<span id="index-HISTIGNOREDUPS"></span>
<span id="index-NOHISTIGNOREDUPS"></span>
<span id="index-history_002c-ignoring-duplicates"></span></p>
<p><code>HIST_IGNORE_DUPS</code> (<code>-h</code>)</p>
<p>Do not enter command lines into the history list if they are duplicates
of the previous event.</p>
<p><span id="index-HIST_005fIGNORE_005fSPACE"></span>
<span id="index-NO_005fHIST_005fIGNORE_005fSPACE"></span>
<span id="index-HISTIGNORESPACE"></span>
<span id="index-NOHISTIGNORESPACE"></span>
<span id="index-history_002c-ignoring-spaces"></span></p>
<p><code>HIST_IGNORE_SPACE</code> (<code>-g</code>)</p>
<p>Remove command lines from the history list when the first character on
the line is a space, or when one of the expanded aliases contains a
leading space. Only normal aliases (not global or suffix aliases) have
this behaviour. Note that the command lingers in the internal history
until the next command is entered before it vanishes, allowing you to
briefly reuse or edit the line. If you want to make it vanish right away
without entering another command, type a space and press return.</p>
<p><span id="index-HIST_005fLEX_005fWORDS"></span>
<span id="index-NO_005fHIST_005fLEX_005fWORDS"></span>
<span id="index-HISTLEXWORDS"></span>
<span id="index-NOHISTLEXWORDS"></span></p>
<p><code>HIST_LEX_WORDS</code></p>
<p>By default, shell history that is read in from files is split into words
on all white space. This means that arguments with quoted whitespace are
not correctly handled, with the consequence that references to words in
history lines that have been read from a file may be inaccurate. When
this option is set, words read in from a history file are divided up in
a similar fashion to normal shell command line handling. Although this
produces more accurately delimited words, if the size of the history
file is large this can be slow. Trial and error is necessary to decide.</p>
<p><span id="index-HIST_005fNO_005fFUNCTIONS"></span>
<span id="index-NO_005fHIST_005fNO_005fFUNCTIONS"></span>
<span id="index-HISTNOFUNCTIONS"></span>
<span id="index-NOHISTNOFUNCTIONS"></span></p>
<p><code>HIST_NO_FUNCTIONS</code></p>
<p>Remove function definitions from the history list. Note that the
function lingers in the internal history until the next command is
entered before it vanishes, allowing you to briefly reuse or edit the
definition.</p>
<p><span id="index-HIST_005fNO_005fSTORE"></span>
<span id="index-NO_005fHIST_005fNO_005fSTORE"></span>
<span id="index-HISTNOSTORE"></span>
<span id="index-NOHISTNOSTORE"></span></p>
<p><code>HIST_NO_STORE</code></p>
<p>Remove the <code>history</code> (<code>fc -l</code>) command from the history list when
invoked. Note that the command lingers in the internal history until the
next command is entered before it vanishes, allowing you to briefly
reuse or edit the line.</p>
<p><span id="index-HIST_005fREDUCE_005fBLANKS"></span>
<span id="index-NO_005fHIST_005fREDUCE_005fBLANKS"></span>
<span id="index-HISTREDUCEBLANKS"></span>
<span id="index-NOHISTREDUCEBLANKS"></span></p>
<p><code>HIST_REDUCE_BLANKS</code></p>
<p>Remove superfluous blanks from each command line being added to the
history list.</p>
<p><span id="index-HIST_005fSAVE_005fBY_005fCOPY"></span>
<span id="index-NO_005fHIST_005fSAVE_005fBY_005fCOPY"></span>
<span id="index-HISTSAVEBYCOPY"></span>
<span id="index-NOHISTSAVEBYCOPY"></span></p>
<p><code>HIST_SAVE_BY_COPY</code> &lt;D&gt;</p>
<p>When the history file is re-written, we normally write out a copy of the
file named <code>$HISTFILE.new</code> and then rename it over the old one. However,
if this option is unset, we instead truncate the old history file and
write out the new version in-place. If one of the history-appending
options is enabled, this option only has an effect when the enlarged
history file needs to be re-written to trim it down to size. Disable
this only if you have special needs, as doing so makes it possible to
lose history entries if zsh gets interrupted during the save.</p>
<p>When writing out a copy of the history file, zsh preserves the old
file’s permissions and group information, but will refuse to write out
a new file if it would change the history file’s owner.</p>
<p><span id="index-HIST_005fSAVE_005fNO_005fDUPS"></span>
<span id="index-NO_005fHIST_005fSAVE_005fNO_005fDUPS"></span>
<span id="index-HISTSAVENODUPS"></span>
<span id="index-NOHISTSAVENODUPS"></span></p>
<p><code>HIST_SAVE_NO_DUPS</code></p>
<p>When writing out the history file, older commands that duplicate newer
ones are omitted.</p>
<p><span id="index-HIST_005fVERIFY"></span>
<span id="index-NO_005fHIST_005fVERIFY"></span>
<span id="index-HISTVERIFY"></span>
<span id="index-NOHISTVERIFY"></span>
<span id="index-history_002c-verifying-substitution"></span></p>
<p><code>HIST_VERIFY</code></p>
<p>Whenever the user enters a line with history expansion, don’t execute
the line directly; instead, perform history expansion and reload the
line into the editing buffer.</p>
<p><span id="index-INC_005fAPPEND_005fHISTORY"></span>
<span id="index-NO_005fINC_005fAPPEND_005fHISTORY"></span>
<span id="index-INCAPPENDHISTORY"></span>
<span id="index-NOINCAPPENDHISTORY"></span>
<span id="index-history_002c-incremental-appending-to-a-file"></span></p>
<p><code>INC_APPEND_HISTORY</code></p>
<p>This option works like <code>APPEND_HISTORY</code> except that new history lines
are added to the <code>$HISTFILE</code> incrementally (as soon as they are
entered), rather than waiting until the shell exits. The file will still
be periodically re-written to trim it when the number of lines grows 20%
beyond the value specified by <code>$SAVEHIST</code> (see also the
<code>HIST_SAVE_BY_COPY</code> option).</p>
<p><span id="index-INC_005fAPPEND_005fHISTORY_005fTIME"></span>
<span id="index-NO_005fINC_005fAPPEND_005fHISTORY_005fTIME"></span>
<span id="index-INCAPPENDHISTORYTIME"></span>
<span id="index-NOINCAPPENDHISTORYTIME"></span>
<span id="index-history_002c-incremental-appending-to-a-file-with-time"></span></p>
<p><code>INC_APPEND_HISTORY_TIME</code></p>
<p>This option is a variant of <code>INC_APPEND_HISTORY</code> in which, where
possible, the history entry is written out to the file after the command
is finished, so that the time taken by the command is recorded correctly
in the history file in <code>EXTENDED_HISTORY</code> format. This means that the
history entry will not be available immediately from other instances of
the shell that are using the same history file.</p>
<p>This option is only useful if <code>INC_APPEND_HISTORY</code> and <code>SHARE_HISTORY</code>
are turned off. The three options should be considered mutually
exclusive.</p>
<p><span id="index-SHARE_005fHISTORY"></span>
<span id="index-NO_005fSHARE_005fHISTORY"></span>
<span id="index-SHAREHISTORY"></span>
<span id="index-NOSHAREHISTORY"></span>
<span id="index-share-history"></span>
<span id="index-history_002c-sharing"></span></p>
<p><code>SHARE_HISTORY</code> &lt;K&gt;</p>
<p>This option both imports new commands from the history file, and also
causes your typed commands to be appended to the history file (the
latter is like specifying <code>INC_APPEND_HISTORY</code>, which should be turned
off if this option is in effect). The history lines are also output with
timestamps ala <code>EXTENDED_HISTORY</code> (which makes it easier to find the
spot where we left off reading the file after it gets re-written).</p>
<p>By default, history movement commands visit the imported lines as well
as the local lines, but you can toggle this on and off with the
set-local-history zle binding. It is also possible to create a zle
widget that will make some commands ignore imported commands, and some
include them.</p>
<p>If you find that you want more control over when commands get imported,
you may wish to turn <code>SHARE_HISTORY</code> off, <code>INC_APPEND_HISTORY</code> or
<code>INC_APPEND_HISTORY_TIME</code> (see above) on, and then manually import
commands whenever you need them using ‘<code>fc -RI</code>’.</p>
<hr />
<p><span id="Initialisation"></span></p>
<h3 id="1625-initialisation"><a class="header" href="#1625-initialisation">16.2.5 Initialisation</a></h3>
<p><span id="index-ALL_005fEXPORT"></span>
<span id="index-NO_005fALL_005fEXPORT"></span>
<span id="index-ALLEXPORT"></span> <span id="index-NOALLEXPORT"></span>
<span id="index-export_002c-automatic"></span></p>
<p><code>ALL_EXPORT</code> (<code>-a</code>, ksh: <code>-a</code>)</p>
<p>All parameters subsequently defined are automatically exported.</p>
<p><span id="index-GLOBAL_005fEXPORT"></span>
<span id="index-NO_005fGLOBAL_005fEXPORT"></span>
<span id="index-GLOBALEXPORT"></span>
<span id="index-NOGLOBALEXPORT"></span>
<span id="index-environment_002c-and-local-parameters"></span></p>
<p><code>GLOBAL_EXPORT</code> &lt;Z&gt;</p>
<p>If this option is set, passing the <code>-x</code> flag to the builtins <code>declare</code>,
<code>float</code>, <code>integer</code>, <code>readonly</code> and <code>typeset</code> (but not <code>local</code>) will also
set the <code>-g</code> flag; hence parameters exported to the environment will not
be made local to the enclosing function, unless they were already or the
flag <code>+g</code> is given explicitly. If the option is unset, exported
parameters will be made local in just the same way as any other
parameter.</p>
<p>This option is set by default for backward compatibility; it is not
recommended that its behaviour be relied upon. Note that the builtin
<code>export</code> always sets both the <code>-x</code> and <code>-g</code> flags, and hence its effect
extends beyond the scope of the enclosing function; this is the</p>
<p><span id="index-exporting_002c-and-local-parameters"></span>
<span id="index-GLOBAL_005fRCS"></span>
<span id="index-NO_005fGLOBAL_005fRCS"></span>
<span id="index-GLOBALRCS"></span> <span id="index-NOGLOBALRCS"></span>
<span id="index-startup-files_002c-global_002c-inhibiting"></span>
<span id="index-files_002c-global-startup_002c-inhibiting"></span></p>
<p><code>GLOBAL_RCS</code> (<code>-d</code>) &lt;D&gt;</p>
<p>If this option is unset, the startup files <code>/etc/zprofile</code>,
<code>/etc/zshrc</code>, <code>/etc/zlogin</code> and <code>/etc/zlogout</code> will not be run. It can
be disabled and re-enabled at any time, including inside local startup
files (<code>.zshrc</code>, etc.).</p>
<p><span id="index-RCS"></span> <span id="index-NO_005fRCS"></span>
<span id="index-NORCS"></span>
<span id="index-startup-files_002c-sourcing"></span></p>
<p><code>RCS</code> (<code>+f</code>) &lt;D&gt;</p>
<p>After <code>/etc/zshenv</code> is sourced on startup, source the <code>.zshenv</code>,
<code>/etc/zprofile</code>, <code>.zprofile</code>, <code>/etc/zshrc</code>, <code>.zshrc</code>, <code>/etc/zlogin</code>,
<code>.zlogin</code>, and <code>.zlogout</code> files, as described in
<a href="Files.html#Files">Files</a>. If this option is unset, the <code>/etc/zshenv</code>
file is still sourced, but any of the others will not be; it can be set
at any time to prevent the remaining startup files after the currently
executing one from being sourced.</p>
<hr />
<p><span id="Input_002fOutput"></span></p>
<h3 id="1626-inputoutput"><a class="header" href="#1626-inputoutput">16.2.6 Input/Output</a></h3>
<p><span id="index-ALIASES"></span> <span id="index-NO_005fALIASES"></span>
<span id="index-NOALIASES"></span>
<span id="index-aliases_002c-expansion"></span></p>
<p><code>ALIASES</code> &lt;D&gt;</p>
<p>Expand aliases.</p>
<p><span id="index-CLOBBER"></span> <span id="index-NO_005fCLOBBER"></span>
<span id="index-NOCLOBBER"></span>
<span id="index-clobbering_002c-of-files"></span>
<span id="index-file-clobbering_002c-allowing"></span></p>
<p><code>CLOBBER</code> (<code>+C</code>, ksh: <code>+C</code>) &lt;D&gt;</p>
<p>Allows ‘<code>&gt;</code>’ redirection to truncate existing files. Otherwise ‘<code>&gt;!</code>’ or
‘<code>&gt;|</code>’ must be used to truncate a file.</p>
<p>If the option is not set, and the option <code>APPEND_CREATE</code> is also not
set, ‘<code>&gt;&gt;!</code>’ or ‘<code>&gt;&gt;|</code>’ must be used to create a file. If either option
is set, ‘<code>&gt;&gt;</code>’ may be used.</p>
<p><span id="index-CORRECT"></span> <span id="index-NO_005fCORRECT"></span>
<span id="index-NOCORRECT"></span>
<span id="index-correction_002c-spelling"></span>
<span id="index-spelling-correction"></span></p>
<p><code>CORRECT</code> (<code>-0</code>)</p>
<p>Try to correct the spelling of commands. Note that, when the
<code>HASH_LIST_ALL</code> option is not set or when some directories in the path
are not readable, this may falsely report spelling errors the first time
some commands are used.</p>
<p>The shell variable <code>CORRECT_IGNORE</code> may be set to a pattern to match
words that will never be offered as corrections.</p>
<p><span id="index-CORRECT_005fALL"></span>
<span id="index-NO_005fCORRECT_005fALL"></span>
<span id="index-CORRECTALL"></span>
<span id="index-NOCORRECTALL"></span></p>
<p><code>CORRECT_ALL</code> (<code>-O</code>)</p>
<p>Try to correct the spelling of all arguments in a line.</p>
<p>The shell variable <code>CORRECT_IGNORE_FILE</code> may be set to a pattern to
match file names that will never be offered as corrections.</p>
<p><span id="index-DVORAK"></span> <span id="index-NO_005fDVORAK"></span>
<span id="index-NODVORAK"></span></p>
<p><code>DVORAK</code></p>
<p>Use the Dvorak keyboard instead of the standard qwerty keyboard as a
basis for examining spelling mistakes for the <code>CORRECT</code> and
<code>CORRECT_ALL</code> options and the <code>spell-word</code> editor command.</p>
<p><span id="index-FLOW_005fCONTROL"></span>
<span id="index-NO_005fFLOW_005fCONTROL"></span>
<span id="index-FLOWCONTROL"></span>
<span id="index-NOFLOWCONTROL"></span>
<span id="index-flow-control"></span></p>
<p><code>FLOW_CONTROL</code> &lt;D&gt;</p>
<p>If this option is unset, output flow control via start/stop characters
(usually assigned to ^S/^Q) is disabled in the shell’s editor.</p>
<p><span id="index-IGNORE_005fEOF"></span>
<span id="index-NO_005fIGNORE_005fEOF"></span>
<span id="index-IGNOREEOF"></span> <span id="index-NOIGNOREEOF"></span>
<span id="index-EOF_002c-ignoring"></span></p>
<p><code>IGNORE_EOF</code> (<code>-7</code>)</p>
<p>Do not exit on end-of-file. Require the use of <code>exit</code> or <code>logout</code>
instead. However, ten consecutive EOFs will cause the shell to exit
anyway, to avoid the shell hanging if its tty goes away.</p>
<p>Also, if this option is set and the Zsh Line Editor is used, widgets
implemented by shell functions can be bound to EOF (normally Control-D)
without printing the normal warning message. This works only for normal
widgets, not for completion widgets.</p>
<p><span id="index-INTERACTIVE_005fCOMMENTS"></span>
<span id="index-NO_005fINTERACTIVE_005fCOMMENTS"></span>
<span id="index-INTERACTIVECOMMENTS"></span>
<span id="index-NOINTERACTIVECOMMENTS"></span>
<span id="index-comments_002c-in-interactive-shells"></span></p>
<p><code>INTERACTIVE_COMMENTS</code> (<code>-k</code>) &lt;K&gt; &lt;S&gt;</p>
<p>Allow comments even in interactive shells.</p>
<p><span id="index-HASH_005fCMDS"></span>
<span id="index-NO_005fHASH_005fCMDS"></span>
<span id="index-HASHCMDS"></span> <span id="index-NOHASHCMDS"></span>
<span id="index-hashing_002c-of-commands"></span>
<span id="index-command-hashing"></span></p>
<p><code>HASH_CMDS</code> &lt;D&gt;</p>
<p>Note the location of each command the first time it is executed.
Subsequent invocations of the same command will use the saved location,
avoiding a path search. If this option is unset, no path hashing is done
at all. However, when <code>CORRECT</code> is set, commands whose names do not
appear in reporting them as spelling errors.</p>
<p><span id="index-HASH_005fDIRS"></span>
<span id="index-NO_005fHASH_005fDIRS"></span>
<span id="index-HASHDIRS"></span> <span id="index-NOHASHDIRS"></span>
<span id="index-hashing_002c-of-directories"></span>
<span id="index-directories_002c-hashing"></span></p>
<p><code>HASH_DIRS</code> &lt;D&gt;</p>
<p>Whenever a command name is hashed, hash the directory containing it, as
well as all directories that occur earlier in the path. Has no effect if
neither <code>HASH_CMDS</code> nor <code>CORRECT</code> is set.</p>
<p><span id="index-HASH_005fEXECUTABLES_005fONLY"></span>
<span id="index-NO_005fHASH_005fEXECUTABLES_005fONLY"></span>
<span id="index-HASHEXECUTABLESONLY"></span>
<span id="index-NOHASHEXECUTABLESONLY"></span></p>
<p><code>HASH_EXECUTABLES_ONLY</code></p>
<p>When hashing commands because of <code>HASH_CMDS</code>, check that the is unset by
default as if the path contains a large number of commands, or consists
of many remote files, the additional tests can take a long time. Trial
and error is needed to show if this option is beneficial.</p>
<p><span id="index-MAIL_005fWARNING"></span>
<span id="index-NO_005fMAIL_005fWARNING"></span>
<span id="index-MAILWARNING"></span>
<span id="index-NOMAILWARNING"></span>
<span id="index-mail_002c-warning-of-reading"></span></p>
<p><code>MAIL_WARNING</code> (<code>-U</code>)</p>
<p>Print a warning message if a mail file has been accessed since the shell
last checked.</p>
<p><span id="index-PATH_005fDIRS"></span>
<span id="index-NO_005fPATH_005fDIRS"></span>
<span id="index-PATHDIRS"></span> <span id="index-NOPATHDIRS"></span>
<span id="index-path-search_002c-extended"></span></p>
<p><code>PATH_DIRS</code> (<code>-Q</code>)</p>
<p>Perform a path search even on command names with slashes in them. Thus
if ‘<code>/usr/local/bin</code>’ is in the user’s path, and he or she types
‘<code>X11/xinit</code>’, the command ‘<code>/usr/local/bin/X11/xinit</code>’ will be
executed (assuming it exists). Commands explicitly beginning with ‘<code>/</code>’,
‘<code>./</code>’ or ‘<code>../</code>’ are not subject to the path search. This also applies
to the ‘<code>.</code>’ and <code>source</code> builtins.</p>
<p>Note that subdirectories of the current directory are always searched
for indicated by this option, and regardless of whether ‘<code>.</code>’ or the
current directory appear in the command search path.</p>
<p><span id="index-PATH_005fSCRIPT"></span>
<span id="index-NO_005fPATH_005fSCRIPT"></span>
<span id="index-PATHSCRIPT"></span>
<span id="index-NOPATHSCRIPT"></span>
<span id="index-path-search_002c-for-script-argument-to-shell"></span></p>
<p><code>PATH_SCRIPT</code> &lt;K&gt; &lt;S&gt;</p>
<p>If this option is not set, a script passed as the first non-option
argument to the shell must contain the name of the file to open. If this
option is set, and the script does not specify a directory path, the
script is looked for first in the current directory, then in the command
path. See <a href="Invocation.html#Invocation">Invocation</a>.</p>
<p><span id="index-PRINT_005fEIGHT_005fBIT"></span>
<span id="index-NO_005fPRINT_005fEIGHT_005fBIT"></span>
<span id="index-PRINTEIGHTBIT"></span>
<span id="index-NOPRINTEIGHTBIT"></span>
<span id="index-eight-bit-characters_002c-printing"></span></p>
<p><code>PRINT_EIGHT_BIT</code></p>
<p>Print eight bit characters literally in completion lists, etc. This
option is not necessary if your system correctly returns the
printability of eight bit characters (see man page ctype(3)).</p>
<p><span id="index-PRINT_005fEXIT_005fVALUE"></span>
<span id="index-NO_005fPRINT_005fEXIT_005fVALUE"></span>
<span id="index-PRINTEXITVALUE"></span>
<span id="index-NOPRINTEXITVALUE"></span>
<span id="index-exit-status_002c-printing"></span></p>
<p><code>PRINT_EXIT_VALUE</code> (<code>-1</code>)</p>
<p>Print the exit value of programs with non-zero exit status. This is only
available at the command line in interactive shells.</p>
<p><span id="index-RC_005fQUOTES"></span>
<span id="index-NO_005fRC_005fQUOTES"></span>
<span id="index-RCQUOTES"></span> <span id="index-NORCQUOTES"></span>
<span id="index-rc_002c-quoting-style"></span>
<span id="index-quoting-style_002c-rc"></span></p>
<p><code>RC_QUOTES</code></p>
<p>Allow the character sequence ‘<code>’’</code>’ to signify a single quote within
singly quoted strings. Note this does not apply in quoted strings using
the format <code>$’``...``’</code>, where a backslashed single quote can be used.</p>
<p><span id="index-RM_005fSTAR_005fSILENT"></span>
<span id="index-NO_005fRM_005fSTAR_005fSILENT"></span>
<span id="index-RMSTARSILENT"></span>
<span id="index-NORMSTARSILENT"></span>
<span id="index-rm-_002a_002c-querying-before"></span>
<span id="index-querying-before-rm-_002a"></span></p>
<p><code>RM_STAR_SILENT</code> (<code>-H</code>) &lt;K&gt; &lt;S&gt;</p>
<p>Do not query the user before executing ‘<code>rm *</code>’ or ‘<code>rm path/*</code>’.</p>
<p><span id="index-RM_005fSTAR_005fWAIT"></span>
<span id="index-NO_005fRM_005fSTAR_005fWAIT"></span>
<span id="index-RMSTARWAIT"></span>
<span id="index-NORMSTARWAIT"></span>
<span id="index-rm-_002a_002c-waiting-before"></span>
<span id="index-waiting-before-rm-_002a"></span></p>
<p><code>RM_STAR_WAIT</code></p>
<p>If querying the user before executing ‘<code>rm *</code>’ or ‘<code>rm path/*</code>’, first
wait ten seconds and ignore anything typed in that time. This avoids the
problem of reflexively answering ‘yes’ to the query when one didn’t
really mean it. The wait and query can always be avoided by expanding
the ‘<code>*</code>’ in ZLE (with tab).</p>
<p><span id="index-SHORT_005fLOOPS"></span>
<span id="index-NO_005fSHORT_005fLOOPS"></span>
<span id="index-SHORTLOOPS"></span>
<span id="index-NOSHORTLOOPS"></span></p>
<p><code>SHORT_LOOPS</code> &lt;C&gt; &lt;Z&gt;</p>
<p>Allow the short forms of <code>for</code>, <code>repeat</code>, <code>select</code>, <code>if</code>, and <code>function</code>
constructs.</p>
<p><span id="index-SUN_005fKEYBOARD_005fHACK"></span>
<span id="index-NO_005fSUN_005fKEYBOARD_005fHACK"></span>
<span id="index-SUNKEYBOARDHACK"></span>
<span id="index-NOSUNKEYBOARDHACK"></span>
<span id="index-sun-keyboard_002c-annoying"></span>
<span id="index-annoying-keyboard_002c-sun"></span></p>
<p><code>SUN_KEYBOARD_HACK</code> (<code>-L</code>)</p>
<p>If a line ends with a backquote, and there are an odd number of
backquotes on the line, ignore the trailing backquote. This is useful on
some keyboards where the return key is too small, and the backquote key
lies annoyingly close to it. As an alternative the variable
<code>KEYBOARD_HACK</code> lets you choose the character to be removed.</p>
<hr />
<p><span id="Job-Control"></span></p>
<h3 id="1627-job-control"><a class="header" href="#1627-job-control">16.2.7 Job Control</a></h3>
<p><span id="index-AUTO_005fCONTINUE"></span>
<span id="index-NO_005fAUTO_005fCONTINUE"></span>
<span id="index-AUTOCONTINUE"></span>
<span id="index-NOAUTOCONTINUE"></span>
<span id="index-jobs_002c-continuing-automatically"></span>
<span id="index-continuing-jobs-automatically"></span></p>
<p><code>AUTO_CONTINUE</code></p>
<p>with the <code>disown</code> builtin command are automatically sent a <code>CONT</code> signal
to make them running.</p>
<p><span id="index-AUTO_005fRESUME"></span>
<span id="index-NO_005fAUTO_005fRESUME"></span>
<span id="index-AUTORESUME"></span>
<span id="index-NOAUTORESUME"></span>
<span id="index-jobs_002c-resuming-automatically"></span>
<span id="index-resuming-jobs-automatically"></span></p>
<p><code>AUTO_RESUME</code> (<code>-W</code>)</p>
<p>Treat single word simple commands without redirection as candidates for
resumption of an existing job.</p>
<p><span id="index-BG_005fNICE"></span>
<span id="index-NO_005fBG_005fNICE"></span>
<span id="index-BGNICE"></span> <span id="index-NOBGNICE"></span>
<span id="index-jobs_002c-background-priority"></span>
<span id="index-background-jobs_002c-priority-of"></span>
<span id="index-priority-of-background-jobs"></span></p>
<p><code>BG_NICE</code> (<code>-6</code>) &lt;C&gt; &lt;Z&gt;</p>
<p>Run all background jobs at a lower priority. This option is set by
default.</p>
<p><span id="index-CHECK_005fJOBS"></span>
<span id="index-NO_005fCHECK_005fJOBS"></span>
<span id="index-CHECKJOBS"></span> <span id="index-NOCHECKJOBS"></span>
<span id="index-exiting_002c-checking-jobs-when"></span>
<span id="index-logging-out_002c-checking-jobs-when"></span></p>
<p><code>CHECK_JOBS</code> &lt;Z&gt;</p>
<p>Report the status of background and suspended jobs before exiting a
shell with job control; a second attempt to exit the shell will succeed.
<code>NO_CHECK_JOBS</code> is best used only in combination with <code>NO_HUP</code>, else
such jobs will be killed automatically.</p>
<p>The check is omitted if the commands run from the previous command line
included a ‘<code>jobs</code>’ command, since it is assumed the user is aware that
there are background or suspended jobs. A ‘<code>jobs</code>’ command run from one
of the hook functions defined in the section Special Functions in
<a href="Functions.html#Functions">Functions</a> is not counted for this purpose.</p>
<p><span id="index-CHECK_005fRUNNING_005fJOBS"></span>
<span id="index-NO_005fCHECK_005fRUNNING_005fJOBS"></span>
<span id="index-CHECKRUNNINGJOBS"></span>
<span id="index-NOCHECKRUNNINGJOBS"></span>
<span id="index-exiting_002c-checking-running-jobs-when"></span>
<span id="index-logging-out_002c-checking-running-jobs-when"></span></p>
<p><code>CHECK_RUNNING_JOBS</code> &lt;Z&gt;</p>
<p>Check for both running and suspended jobs when <code>CHECK_JOBS</code> is enabled.
When this option is disabled, zsh checks only for suspended jobs, which
matches the default behavior of bash.</p>
<p>This option has no effect unless <code>CHECK_JOBS</code> is set.</p>
<p><span id="index-HUP"></span> <span id="index-NO_005fHUP"></span>
<span id="index-NOHUP"></span> <span id="index-jobs_002c-HUP"></span></p>
<p><code>HUP</code> &lt;Z&gt;</p>
<p>Send the <code>HUP</code> signal to running jobs when the shell exits.</p>
<p><span id="index-LONG_005fLIST_005fJOBS"></span>
<span id="index-NO_005fLONG_005fLIST_005fJOBS"></span>
<span id="index-LONGLISTJOBS"></span>
<span id="index-NOLONGLISTJOBS"></span>
<span id="index-jobs_002c-list-format"></span></p>
<p><code>LONG_LIST_JOBS</code> (<code>-R</code>)</p>
<p>Print job notifications in the long format by default.</p>
<p><span id="index-MONITOR"></span> <span id="index-NO_005fMONITOR"></span>
<span id="index-NOMONITOR"></span>
<span id="index-job-control_002c-allowing"></span></p>
<p><code>MONITOR</code> (<code>-m</code>, ksh: <code>-m</code>)</p>
<p>Allow job control. Set by default in interactive shells.</p>
<p><span id="index-NOTIFY"></span> <span id="index-NO_005fNOTIFY"></span>
<span id="index-NONOTIFY"></span>
<span id="index-background-jobs_002c-notification"></span>
<span id="index-notification-of-background-jobs"></span></p>
<p><code>NOTIFY</code> (<code>-5</code>, ksh: <code>-b</code>) &lt;Z&gt;</p>
<p>Report the status of background jobs immediately, rather than waiting
until just before printing a prompt.</p>
<p><span id="index-POSIX_005fJOBS"></span>
<span id="index-POSIXJOBS"></span>
<span id="index-NO_005fPOSIX_005fJOBS"></span>
<span id="index-NOPOSIXJOBS"></span>
<span id="index-bg_002c-output-in-POSIX-format"></span>
<span id="index-fg_002c-output-in-POSIX-format"></span>
<span id="index-job-control_002c-in-subshell"></span>
<span id="index-jobs_002c-output-in-subshell"></span></p>
<p><code>POSIX_JOBS</code> &lt;K&gt; &lt;S&gt;</p>
<p>This option makes job control more compliant with the POSIX standard.</p>
<p>When the option is not set, the <code>MONITOR</code> option is unset on entry to
subshells, so that job control is no longer active. When the option is
set, the <code>MONITOR</code> option and job control remain active in the subshell,
but note that the subshell has no access to jobs in the parent shell.</p>
<p>When the option is not set, jobs put in the background or foreground
with <code>bg</code> or <code>fg</code> are displayed with the same information that would be
reported by <code>jobs</code>. When the option is set, only the text is printed.
The output from <code>jobs</code> itself is not affected by the option.</p>
<p>When the option is not set, job information from the parent shell is
saved for output within a subshell (for example, within a pipeline).
When the option is set, the output of <code>jobs</code> is empty until a job is
started within the subshell.</p>
<p>In previous versions of the shell, it was necessary to enable
<code>POSIX_JOBS</code> in order for the builtin command <code>wait</code> to return the
status of background jobs that had already exited. This is no longer the
case.</p>
<hr />
<p><span id="Prompting"></span></p>
<h3 id="1628-prompting"><a class="header" href="#1628-prompting">16.2.8 Prompting</a></h3>
<p><span id="index-PROMPT_005fBANG"></span>
<span id="index-NO_005fPROMPT_005fBANG"></span>
<span id="index-PROMPTBANG"></span>
<span id="index-NOPROMPTBANG"></span>
<span id="index-prompt_002c-_0021-expansion"></span></p>
<p><code>PROMPT_BANG</code> &lt;K&gt;</p>
<p>If set, ‘<code>!</code>’ is treated specially in prompt expansion. See <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>.</p>
<p><span id="index-PROMPT_005fCR"></span>
<span id="index-NO_005fPROMPT_005fCR"></span>
<span id="index-PROMPTCR"></span> <span id="index-NOPROMPTCR"></span>
<span id="index-prompt_002c-with-CR"></span></p>
<p><code>PROMPT_CR</code> (<code>+V</code>) &lt;D&gt;</p>
<p>Print a carriage return just before printing a prompt in the line
editor. This is on by default as multi-line editing is only possible if
the editor knows where the start of the line appears.</p>
<p><span id="index-PROMPT_005fSP"></span>
<span id="index-NO_005fPROMPT_005fSP"></span>
<span id="index-PROMPTSP"></span> <span id="index-NOPROMPTSP"></span>
<span id="index-prompt_002c-save-partial-lines"></span></p>
<p><code>PROMPT_SP</code> &lt;D&gt;</p>
<p>Attempt to preserve a partial line (i.e. a line that did not end with a
newline) that would otherwise be covered up by the command prompt due to
the <code>PROMPT_CR</code> option. This works by outputting some cursor-control
characters, including a series of spaces, that should make the terminal
wrap to the next line when a partial line is present (note that this is
only successful if your terminal has automatic margins, which is
typical).</p>
<p>When a partial line is preserved, by default you will see an
inverse+bold character at the end of the partial line: a ‘<code>%</code>’ for a
normal user or a ‘<code>#</code>’ for root. If set, the shell parameter
<code>PROMPT_EOL_MARK</code> can be used to customize how the end of partial lines
are shown.</p>
<p>NOTE: if the <code>PROMPT_CR</code> option is not set, enabling this option will
have no effect. This option is on by default.</p>
<p><span id="index-PROMPT_005fPERCENT"></span>
<span id="index-NO_005fPROMPT_005fPERCENT"></span>
<span id="index-PROMPTPERCENT"></span>
<span id="index-NOPROMPTPERCENT"></span>
<span id="index-prompt_002c-_0025-expansion"></span></p>
<p><code>PROMPT_PERCENT</code> &lt;C&gt; &lt;Z&gt;</p>
<p>If set, ‘<code>%</code>’ is treated specially in prompt expansion. See <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>.</p>
<p><span id="index-PROMPT_005fSUBST"></span>
<span id="index-NO_005fPROMPT_005fSUBST"></span>
<span id="index-PROMPTSUBST"></span>
<span id="index-NOPROMPTSUBST"></span>
<span id="index-prompt_002c-parameter-expansion"></span></p>
<p><code>PROMPT_SUBST</code> &lt;K&gt; &lt;S&gt;</p>
<p>If set, <em>parameter expansion</em>, <em>command substitution</em> and <em>arithmetic
expansion</em> are performed in prompts. Substitutions within prompts do not
affect the command status.</p>
<p><span id="index-TRANSIENT_005fRPROMPT"></span>
<span id="index-NO_005fTRANSIENT_005fRPROMPT"></span>
<span id="index-TRANSIENTRPROMPT"></span>
<span id="index-NOTRANSIENTRPROMPT"></span></p>
<p><code>TRANSIENT_RPROMPT</code></p>
<p>Remove any right prompt from display when accepting a command line. This
may be useful with terminals with other cut/paste methods.</p>
<hr />
<p><span id="Scripts-and-Functions"></span></p>
<h3 id="1629-scripts-and-functions"><a class="header" href="#1629-scripts-and-functions">16.2.9 Scripts and Functions</a></h3>
<p><span id="index-ALIAS_005fFUNC_005fDEF"></span>
<span id="index-NO_005fALIAS_005fFUNC_005fDEF"></span>
<span id="index-ALIASFUNCDEF"></span>
<span id="index-NOALIASFUNCDEF"></span>
<span id="index-functions_002c-defining-with-expanded-aliases"></span>
<span id="index-aliases_002c-expanding-in-function-definition"></span></p>
<p><code>ALIAS_FUNC_DEF</code> &lt;S&gt;</p>
<p>By default, zsh does not allow the definition of functions using the
‘<code>name</code> <code>()</code>’ syntax if <code>name</code> was expanded as an alias: this causes
an error. This is usually the desired behaviour, as otherwise the
combination of an alias and a function based on the same definition can
easily cause problems.</p>
<p>When this option is set, aliases can be used for defining functions.</p>
<p>For example, consider the following definitions as they might occur in a
startup file.</p>
<div class="example">
<pre><code class="language-example">alias foo=bar
foo() {
print This probably does not do what you expect.
}
</code></pre>
</div>
<p>Here, <code>foo</code> is expanded as an alias to <code>bar</code> before the <code>()</code> is
encountered, so the function defined would be named <code>bar</code>. By default
this is instead an error in native mode. Note that quoting any part of
the function name, or using the keyword <code>function</code>, avoids the problem,
so is recommended when the function name can also be an alias.</p>
<p><span id="index-C_005fBASES"></span>
<span id="index-NO_005fC_005fBASES"></span>
<span id="index-CBASES"></span> <span id="index-NOCBASES"></span>
<span id="index-bases_002c-output-in-C-format"></span>
<span id="index-hexadecimal_002c-output-in-C-format"></span>
<span id="index-octal_002c-output-in-C-format"></span></p>
<p><code>C_BASES</code></p>
<p>Output hexadecimal numbers in the standard C format, for example
‘<code>0xFF</code>’ instead of the usual ‘<code>16#FF</code>’. If the option
<code>OCTAL_ZEROES</code> is also set (it is not by default), octal numbers will be
treated similarly and hence appear as ‘<code>077</code>’ instead of ‘<code>8#77</code>’. This
option has no effect on the choice of the output base, nor on the output
of bases other than hexadecimal and octal. Note that these formats will
be understood on input irrespective of the setting of <code>C_BASES</code>.</p>
<p><span id="index-C_005fPRECEDENCES"></span>
<span id="index-NO_005fC_005fPRECEDENCES"></span>
<span id="index-CPRECEDENCES"></span>
<span id="index-NOCPRECEDENCES"></span>
<span id="index-precedence_002c-operator"></span>
<span id="index-operator-precedence"></span></p>
<p><code>C_PRECEDENCES</code></p>
<p>This alters the precedence of arithmetic operators to be more like C and
other programming languages; <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a> has an
explicit list.</p>
<p><span id="index-DEBUG_005fBEFORE_005fCMD"></span>
<span id="index-NO_005fDEBUG_005fBEFORE_005fCMD"></span>
<span id="index-DEBUGBEFORECMD"></span>
<span id="index-NODEBUGBEFORECMD"></span>
<span id="index-traps_002c-DEBUG_002c-before-or-after-command"></span>
<span id="index-DEBUG-trap_002c-before-or-after-command"></span></p>
<p><code>DEBUG_BEFORE_CMD</code> &lt;D&gt;</p>
<p>Run the <code>DEBUG</code> trap before each command; otherwise it is run after each
command. Setting this option mimics the behaviour of ksh 93; with the
option unset the behaviour is that of ksh 88.</p>
<p><span id="index-ERR_005fEXIT"></span>
<span id="index-NO_005fERR_005fEXIT"></span>
<span id="index-ERREXIT"></span> <span id="index-NOERREXIT"></span>
<span id="index-exit-status_002c-trapping"></span></p>
<p><code>ERR_EXIT</code> (<code>-e</code>, ksh: <code>-e</code>)</p>
<p>If a command has a non-zero exit status, execute the <code>ZERR</code> trap, if
set, and exit. This is disabled while running initialization scripts.</p>
<p>The behaviour is also disabled inside <code>DEBUG</code> traps. In this case the
option is handled specially: it is unset on entry to the trap. If the
option <code>DEBUG_BEFORE_CMD</code> is set, as it is by default, and the option
<code>ERR_EXIT</code> is found to have been set on exit, then the command for which
the <code>DEBUG</code> trap is being executed is skipped. The option is restored
after the trap exits.</p>
<p>Non-zero status in a command list containing <code>&amp;&amp;</code> or <code>||</code> is ignored for
commands not at the end of the list. Hence</p>
<div class="example">
<pre><code class="language-example">false &amp;&amp; true
</code></pre>
</div>
<p>does not trigger exit.</p>
<p>Exiting due to <code>ERR_EXIT</code> has certain interactions with asynchronous
jobs noted in <a href="Jobs-_0026-Signals.html#Jobs-_0026-Signals">Jobs &amp;
Signals</a>.</p>
<p><span id="index-ERR_005fRETURN"></span>
<span id="index-NO_005fERR_005fRETURN"></span>
<span id="index-ERRRETURN"></span> <span id="index-NOERRRETURN"></span>
<span id="index-function-return_002c-on-error"></span>
<span id="index-return-from-function_002c-on-error"></span></p>
<p><code>ERR_RETURN</code></p>
<p>If a command has a non-zero exit status, return immediately from the
enclosing function. The logic is similar to that for <code>ERR_EXIT</code>, except
that an implicit <code>return</code> statement is executed instead of an <code>exit</code>.
This will trigger an exit at the outermost level of a non-interactive
script.</p>
<p>Normally this option inherits the behaviour of <code>ERR_EXIT</code> that code
followed by ‘<code>&amp;&amp;</code>’ ‘<code>||</code>’ does not trigger a return. Hence in the
following:</p>
<div class="example">
<pre><code class="language-example">summit || true
</code></pre>
</div>
<p>no return is forced as the combined effect always has a zero return
status.</p>
<p>Note. however, that if <code>summit</code> in the above example is itself a
function, code inside it is considered separately: it may force a return
from <code>summit</code> (assuming the option remains set within <code>summit</code>), but not
from the enclosing context. This behaviour is different from <code>ERR_EXIT</code>
which is unaffected by function scope.</p>
<p><span id="index-EVAL_005fLINENO"></span>
<span id="index-NO_005fEVAL_005fLINENO"></span>
<span id="index-EVALLINENO"></span>
<span id="index-NOEVALLINENO"></span>
<span id="index-line-number_002c-in-evaluated-expression"></span></p>
<p><code>EVAL_LINENO</code> &lt;Z&gt;</p>
<p>If set, line numbers of expressions evaluated using the builtin <code>eval</code>
are tracked separately of the enclosing environment. This applies both
to the parameter <code>LINENO</code> and the line number output by the prompt
escape <code>%i</code>. If the option is set, the prompt escape <code>%N</code> will output
the string ‘<code>(eval)</code>’ instead of the script or function name as an
indication. (The two prompt escapes are typically used in the parameter
<code>PS4</code> to be output when the option <code>XTRACE</code> is set.) If <code>EVAL_LINENO</code> is
unset, the line number of the surrounding script or function is retained
during the evaluation.</p>
<p><span id="index-EXEC"></span> <span id="index-NO_005fEXEC"></span>
<span id="index-NOEXEC"></span>
<span id="index-command-execution_002c-enabling"></span></p>
<p><code>EXEC</code> (<code>+n</code>, ksh: <code>+n</code>) &lt;D&gt;</p>
<p>Do execute commands. Without this option, commands are read and checked
for syntax errors, but not executed. This option cannot be turned off in
an interactive shell, except when ‘<code>-n</code>’ is supplied to the shell at
startup.</p>
<p><span id="index-FUNCTION_005fARGZERO"></span>
<span id="index-NO_005fFUNCTION_005fARGZERO"></span>
<span id="index-FUNCTIONARGZERO"></span>
<span id="index-NOFUNCTIONARGZERO"></span>
<span id="index-_00240_002c-setting"></span></p>
<p><code>FUNCTION_ARGZERO</code> &lt;C&gt; &lt;Z&gt;</p>
<p>When executing a shell function or sourcing a script, set <code>$0</code>
temporarily to the name of the function/script. Note that toggling
<code>FUNCTION_ARGZERO</code> from on to off (or off to on) does not change the
current value of <code>$0</code>. Only the state upon entry to the function or
script has an effect. Compare <code>POSIX_ARGZERO</code>.</p>
<p><span id="index-LOCAL_005fLOOPS"></span>
<span id="index-NO_005fLOCAL_005fLOOPS"></span>
<span id="index-LOCALLOOPS"></span>
<span id="index-NOLOCALLOOPS"></span>
<span id="index-break_002c-inside-function"></span>
<span id="index-continue_002c-inside-function"></span>
<span id="index-function_002c-scope-of-break-and-continue"></span></p>
<p><code>LOCAL_LOOPS</code></p>
<p>When this option is not set, the effect of <code>break</code> and <code>continue</code>
commands may propagate outside function scope, affecting loops in
calling functions. When the option is set in a calling function, a
<code>break</code> or a <code>continue</code> that is not caught within a called function
(regardless of the setting of the option within that function) produces
a warning and the effect is cancelled.</p>
<p><span id="index-LOCAL_005fOPTIONS"></span>
<span id="index-NO_005fLOCAL_005fOPTIONS"></span>
<span id="index-LOCALOPTIONS"></span>
<span id="index-NOLOCALOPTIONS"></span></p>
<p><code>LOCAL_OPTIONS</code> &lt;K&gt;</p>
<p>If this option is set at the point of return from a shell function, most
options (including this one) which were in force upon entry to the
function are restored; options that are not restored are <code>PRIVILEGED</code>
and <code>RESTRICTED</code>. Otherwise, only this option, and the <code>LOCAL_LOOPS</code>,
<code>XTRACE</code> and <code>PRINT_EXIT_VALUE</code> options are restored. Hence if this is
explicitly unset by a shell function the other options in force at the
point of return will remain so. A shell function can also guarantee
itself a known shell configuration with a formulation like ‘<code>emulate -L zsh</code>’; the <code>-L</code> activates <code>LOCAL_OPTIONS</code>.</p>
<p><span id="index-LOCAL_005fPATTERNS"></span>
<span id="index-NO_005fLOCAL_005fPATTERNS"></span>
<span id="index-LOCALPATTERNS"></span>
<span id="index-NOLOCALPATTERNS"></span></p>
<p><code>LOCAL_PATTERNS</code></p>
<p>If this option is set at the point of return from a shell function, the
state of pattern disables, as set with the builtin command ‘<code>disable -p</code>’, is restored to what it was when the function was entered. The
behaviour of this option is similar to the effect of <code>LOCAL_OPTIONS</code> on
options; hence ‘<code>emulate -L sh</code>’ (or indeed any other emulation with the
<code>-L</code> option) activates <code>LOCAL_PATTERNS</code>.</p>
<p><span id="index-LOCAL_005fTRAPS"></span>
<span id="index-NO_005fLOCAL_005fTRAPS"></span>
<span id="index-LOCALTRAPS"></span>
<span id="index-NOLOCALTRAPS"></span></p>
<p><code>LOCAL_TRAPS</code> &lt;K&gt;</p>
<p>If this option is set when a signal trap is set inside a function, then
the previous status of the trap for that signal will be restored when
the function exits. Note that this option must be set <em>prior</em> to
altering the trap behaviour in a function; unlike <code>LOCAL_OPTIONS</code>, the
value on exit from the function is irrelevant. However, it does not need
to be set before any global trap for that to be correctly restored by a
function. For example,</p>
<div class="example">
<pre><code class="language-example">unsetopt localtraps
trap - INT
fn() { setopt localtraps; trap '' INT; sleep 3; }
</code></pre>
</div>
<p>will restore normal handling of <code>SIGINT</code> after the function exits.</p>
<p><span id="index-MULTI_005fFUNC_005fDEF"></span>
<span id="index-NO_005fMULTI_005fFUNC_005fDEF"></span>
<span id="index-MULTIFUNCDEF"></span>
<span id="index-NOMULTIFUNCDEF"></span></p>
<p><code>MULTI_FUNC_DEF</code> &lt;Z&gt;</p>
<p>Allow definitions of multiple functions at once in the form ‘<code>fn1 fn2``...``()</code>’; if the option is not set, this causes a parse error.
Definition of multiple functions with the <code>function</code> keyword is always
allowed. Multiple function definitions are not often used and can cause
obscure errors.</p>
<p><span id="index-MULTIOS"></span> <span id="index-NO_005fMULTIOS"></span>
<span id="index-NOMULTIOS"></span></p>
<p><code>MULTIOS</code> &lt;Z&gt;</p>
<p>Perform implicit tees or cats when multiple redirections are attempted
(see <a href="Redirection.html#Redirection">Redirection</a>).</p>
<p><span id="index-OCTAL_005fZEROES"></span>
<span id="index-NO_005fOCTAL_005fZEROES"></span>
<span id="index-OCTALZEROES"></span>
<span id="index-NOOCTALZEROES"></span>
<span id="index-octal_002c-arithmetic-expressions"></span></p>
<p><code>OCTAL_ZEROES</code> &lt;S&gt;</p>
<p>Interpret any integer constant beginning with a 0 as octal, per IEEE Std
1003.2-1992 (ISO 9945-2:1993). This is not enabled by default as it
causes problems with parsing of, for example, date and time strings with
leading zeroes.</p>
<p>Sequences of digits indicating a numeric base such as the ‘<code>08</code>’
component in ‘<code>08#77</code>’ are always interpreted as decimal, regardless of
leading zeroes.</p>
<p><span id="index-PIPE_005fFAIL"></span>
<span id="index-NO_005fPIPE_005fFAIL"></span>
<span id="index-PIPEFAIL"></span> <span id="index-NOPIPEFAIL"></span>
<span id="index-exit-status-from-pipeline"></span>
<span id="index-status_002c-on-exit-from-pipeline"></span>
<span id="index-pipeline_002c-exit-status-from"></span></p>
<p><code>PIPE_FAIL</code></p>
<p>By default, when a pipeline exits the exit status recorded by the shell
and returned by the shell variable <code>$?</code> reflects that of the rightmost
element of a pipeline. If this option is set, the exit status instead
reflects the status of the rightmost element of the pipeline that was
non-zero, or zero if all elements exited with zero status.</p>
<p><span id="index-SOURCE_005fTRACE"></span>
<span id="index-NO_005fSOURCE_005fTRACE"></span>
<span id="index-SOURCETRACE"></span>
<span id="index-NOSOURCETRACE"></span></p>
<p><code>SOURCE_TRACE</code></p>
<p>If set, zsh will print an informational message announcing the name of
each file it loads. The format of the output is similar to that for the
<code>XTRACE</code> option, with the message <code>&lt;sourcetrace&gt;</code>. A file may be loaded
by the shell itself when it starts up and shuts down (<code>Startup/Shutdown Files</code>) or by the use of the ‘<code>source</code>’ and ‘<code>dot</code>’ builtin commands.</p>
<p><span id="index-TYPESET_005fSILENT"></span>
<span id="index-NO_005fTYPESET_005fSILENT"></span>
<span id="index-TYPESETSILENT"></span>
<span id="index-NOTYPESETSILENT"></span></p>
<p><code>TYPESET_SILENT</code></p>
<p>If this is unset, executing any of the ‘<code>typeset</code>’ family of commands
with no options and a list of parameters that have no values to be
assigned but already exist will display the value of the parameter. If
the option is set, they will only be shown when parameters are selected
with the ‘<code>-m</code>’ option. The option ‘<code>-p</code>’ is available whether or not
the option is set.</p>
<p><span id="index-VERBOSE"></span> <span id="index-NO_005fVERBOSE"></span>
<span id="index-NOVERBOSE"></span>
<span id="index-tracing_002c-of-input-lines"></span>
<span id="index-input_002c-tracing"></span></p>
<p><code>VERBOSE</code> (<code>-v</code>, ksh: <code>-v</code>)</p>
<p>Print shell input lines as they are read.</p>
<p><span id="index-XTRACE"></span> <span id="index-NO_005fXTRACE"></span>
<span id="index-NOXTRACE"></span>
<span id="index-tracing_002c-of-commands"></span>
<span id="index-commands_002c-tracing"></span></p>
<p><code>XTRACE</code> (<code>-x</code>, ksh: <code>-x</code>)</p>
<p>Print commands and their arguments as they are executed. The output is
preceded by the value of <code>$PS4</code>, formatted as described in <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>.</p>
<hr />
<p><span id="Shell-Emulation"></span></p>
<h3 id="16210-shell-emulation"><a class="header" href="#16210-shell-emulation">16.2.10 Shell Emulation</a></h3>
<p><span id="index-APPEND_005fCREATE"></span>
<span id="index-NO_005fAPPEND_005fCREATE"></span>
<span id="index-APPENDCREATE"></span>
<span id="index-NOAPPENDCREATE"></span>
<span id="index-clobbering_002c-POSIX-compatibility"></span>
<span id="index-file-clobbering_002c-POSIX-compatibility"></span>
<span id="index-no-clobber_002c-POSIX-compatible"></span></p>
<p><code>APPEND_CREATE</code> &lt;K&gt; &lt;S&gt;</p>
<p>This option only applies when <code>NO_CLOBBER</code> (-<code>C</code>) is in effect.</p>
<p>If this option is not set, the shell will report an error when a append
redirection (<code>&gt;&gt;</code>) is used on a file that does not already exists (the
traditional zsh behaviour of <code>NO_CLOBBER</code>). If the option is set, no
error is reported (POSIX behaviour).</p>
<p><span id="index-BASH_005fREMATCH"></span>
<span id="index-NO_005fBASH_005fREMATCH"></span>
<span id="index-BASHREMATCH"></span>
<span id="index-NOBASHREMATCH"></span>
<span id="index-bash_002c-BASH_005fREMATCH-variable"></span>
<span id="index-regexp_002c-bash-BASH_005fREMATCH-variable"></span></p>
<p><code>BASH_REMATCH</code></p>
<p>When set, matches performed with the <code>=~</code> operator will set the
<code>BASH_REMATCH</code> array variable, instead of the default <code>MATCH</code> and
<code>match</code> variables. The first element of the <code>BASH_REMATCH</code> array will
contain the entire matched text and subsequent elements will contain
extracted substrings. This option makes more sense when <code>KSH_ARRAYS</code> is
also set, so that the entire matched portion is stored at index 0 and
the first substring is at index 1. Without this option, the <code>MATCH</code>
variable contains the entire matched text and the <code>match</code> array variable
contains substrings.</p>
<p><span id="index-BSD_005fECHO"></span>
<span id="index-NO_005fBSD_005fECHO"></span>
<span id="index-BSDECHO"></span> <span id="index-NOBSDECHO"></span>
<span id="index-echo_002c-BSD-compatible"></span></p>
<p><code>BSD_ECHO</code> &lt;S&gt;</p>
<p>Make the <code>echo</code> builtin compatible with the BSD man page echo(1)
command. This disables backslashed escape sequences in echo strings
unless the <code>-e</code> option is specified.</p>
<p><span id="index-CONTINUE_005fON_005fERROR"></span>
<span id="index-NO_005fCONTINUE_005fON_005fERROR"></span>
<span id="index-CONTINUEONERROR"></span>
<span id="index-NOCONTINUEONERROR"></span>
<span id="index-error_002c-option-to-continue-script-on"></span></p>
<p><code>CONTINUE_ON_ERROR</code></p>
<p>If a fatal error is encountered (see
<a href="Shell-Grammar.html#Errors">Errors</a>), and the code is running in a
script, the shell will resume execution at the next statement in the
script at the top level, in other words outside all functions or shell
constructs such as loops and conditions. This mimics the behaviour of
interactive shells, where the shell returns to the line editor to read a
new command; it was the normal behaviour in versions of zsh before
5.0.1.</p>
<p><span id="index-CSH_005fJUNKIE_005fHISTORY"></span>
<span id="index-NO_005fCSH_005fJUNKIE_005fHISTORY"></span>
<span id="index-CSHJUNKIEHISTORY"></span>
<span id="index-NOCSHJUNKIEHISTORY"></span>
<span id="index-csh_002c-history-style"></span>
<span id="index-history-style_002c-csh"></span></p>
<p><code>CSH_JUNKIE_HISTORY</code> &lt;C&gt;</p>
<p>A history reference without an event specifier will always refer to the
previous command. Without this option, such a history reference refers
to the same event as the previous history reference on the current
command line, defaulting to the previous command.</p>
<p><span id="index-CSH_005fJUNKIE_005fLOOPS"></span>
<span id="index-NO_005fCSH_005fJUNKIE_005fLOOPS"></span>
<span id="index-CSHJUNKIELOOPS"></span>
<span id="index-NOCSHJUNKIELOOPS"></span>
<span id="index-csh_002c-loop-style"></span>
<span id="index-loop-style_002c-csh"></span></p>
<p><code>CSH_JUNKIE_LOOPS</code> &lt;C&gt;</p>
<p>Allow loop bodies to take the form ‘<code>list``; end</code>’ instead of ‘<code> do ``list``; done</code>’.</p>
<p><span id="index-CSH_005fJUNKIE_005fQUOTES"></span>
<span id="index-NO_005fCSH_005fJUNKIE_005fQUOTES"></span>
<span id="index-CSHJUNKIEQUOTES"></span>
<span id="index-NOCSHJUNKIEQUOTES"></span>
<span id="index-csh_002c-quoting-style"></span>
<span id="index-quoting-style_002c-csh"></span></p>
<p><code>CSH_JUNKIE_QUOTES</code> &lt;C&gt;</p>
<p>Changes the rules for single- and double-quoted text to match that of
csh. These require that embedded newlines be preceded by a backslash;
unescaped newlines will cause an error message. In double-quoted
strings, it is made impossible to escape ‘<code>$</code>’, ‘<code>‘</code>’ or ‘<code>&quot;</code>’ (and
‘<code>\</code>’ itself no longer needs escaping). Command substitutions are
only expanded once, and cannot be nested.</p>
<p><span id="index-CSH_005fNULLCMD"></span>
<span id="index-NO_005fCSH_005fNULLCMD"></span>
<span id="index-CSHNULLCMD"></span>
<span id="index-NOCSHNULLCMD"></span>
<span id="index-NULLCMD_002c-ignoring"></span>
<span id="index-READNULLCMD_002c-ignoring"></span>
<span id="index-redirections-with-no-command_002c-csh"></span>
<span id="index-csh_002c-redirections-with-no-command"></span></p>
<p><code>CSH_NULLCMD</code> &lt;C&gt;</p>
<p>Do not use the values of <code>NULLCMD</code> and <code>READNULLCMD</code> when running
redirections with no command. This make such redirections fail (see
<a href="Redirection.html#Redirection">Redirection</a>).</p>
<p><span id="index-KSH_005fARRAYS"></span>
<span id="index-NO_005fKSH_005fARRAYS"></span>
<span id="index-KSHARRAYS"></span> <span id="index-NOKSHARRAYS"></span>
<span id="index-arrays_002c-ksh-style"></span>
<span id="index-array-style_002c-ksh"></span>
<span id="index-ksh_002c-array-style"></span></p>
<p><code>KSH_ARRAYS</code> &lt;K&gt; &lt;S&gt;</p>
<p>Emulate ksh array handling as closely as possible. If this option is
set, array elements are numbered from zero, an array parameter without
subscript refers to the first element instead of the whole array, and
braces are required to delimit a subscript (‘<code>${path[2]}</code>’ rather than
just ‘<code>$path[2]</code>’) or to apply modifiers to any parameter (‘<code>${PWD:h}</code>’
rather than ‘<code>$PWD:h</code>’).</p>
<p><span id="index-KSH_005fAUTOLOAD"></span>
<span id="index-NO_005fKSH_005fAUTOLOAD"></span>
<span id="index-KSHAUTOLOAD"></span>
<span id="index-NOKSHAUTOLOAD"></span></p>
<p><code>KSH_AUTOLOAD</code> &lt;K&gt; &lt;S&gt;</p>
<p>Emulate ksh function autoloading. This means that when a function is
autoloaded, the corresponding file is merely executed, and must define
the function itself. (By default, the function is defined to the
contents of the file. However, the most common ksh-style case - of the
file containing only a simple definition of the function - is always
handled in the ksh-compatible manner.)</p>
<p><span id="index-KSH_005fOPTION_005fPRINT"></span>
<span id="index-NO_005fKSH_005fOPTION_005fPRINT"></span>
<span id="index-KSHOPTIONPRINT"></span>
<span id="index-NOKSHOPTIONPRINT"></span>
<span id="index-option-printing_002c-ksh-style"></span>
<span id="index-option-printing-style_002c-ksh"></span>
<span id="index-ksh_002c-option-printing-style"></span></p>
<p><code>KSH_OPTION_PRINT</code> &lt;K&gt;</p>
<p>Alters the way options settings are printed: instead of separate lists
of set and unset options, all options are shown, marked ‘on’ if they are
in the non-default state, ‘off’ otherwise.</p>
<p><span id="index-KSH_005fTYPESET"></span>
<span id="index-NO_005fKSH_005fTYPESET"></span>
<span id="index-KSHTYPESET"></span>
<span id="index-NOKSHTYPESET"></span>
<span id="index-argument-splitting_002c-in-typeset-etc_002e"></span>
<span id="index-ksh_002c-argument-splitting-in-typeset"></span></p>
<p><code>KSH_TYPESET</code></p>
<p>This option is now obsolete: a better appropximation to the behaviour of
other shells is obtained with the reserved word interface to <code>declare</code>,
<code>export</code>, <code>float</code>, <code>integer</code>, <code>local</code>, <code>readonly</code> and <code>typeset</code>. Note
that the option is only applied when the reserved word interface is
<em>not</em> in use.</p>
<p>Alters the way arguments to the <code>typeset</code> family of commands, including
<code>declare</code>, <code>export</code>, <code>float</code>, <code>integer</code>, <code>local</code> and <code>readonly</code>, are
processed. Without this option, zsh will perform normal word splitting
after command and parameter expansion in arguments of an assignment;
with it, word splitting does not take place in those cases.</p>
<p><span id="index-KSH_005fZERO_005fSUBSCRIPT"></span>
<span id="index-NO_005fKSH_005fZERO_005fSUBSCRIPT"></span>
<span id="index-KSHZEROSUBSCRIPT"></span>
<span id="index-NOKSHZEROSUBSCRIPT"></span>
<span id="index-arrays_002c-behaviour-of-index-zero"></span></p>
<p><code>KSH_ZERO_SUBSCRIPT</code></p>
<p>Treat use of a subscript of value zero in array or string expressions as
a reference to the first element, i.e. the element that usually has the
subscript 1. Ignored if <code>KSH_ARRAYS</code> is also set.</p>
<p>If neither this option nor <code>KSH_ARRAYS</code> is set, accesses to an element
of an array or string with subscript zero return an empty element or
string, while attempts to set element zero of an array or string are
treated as an error. However, attempts to set an otherwise valid
subscript range that includes zero will succeed. For example, if
<code>KSH_ZERO_SUBSCRIPT</code> is not set,</p>
<div class="example">
<pre><code class="language-example">array[0]=(element)
</code></pre>
</div>
<p>is an error, while</p>
<div class="example">
<pre><code class="language-example">array[0,1]=(element)
</code></pre>
</div>
<p>is not and will replace the first element of the array.</p>
<p>This option is for compatibility with older versions of the shell and is
not recommended in new code.</p>
<p><span id="index-POSIX_005fALIASES"></span>
<span id="index-NO_005fPOSIX_005fALIASES"></span>
<span id="index-POSIXALIASES"></span>
<span id="index-NOPOSIXALIASES"></span></p>
<p><code>POSIX_ALIASES</code> &lt;K&gt; &lt;S&gt;</p>
<p>When this option is set, reserved words are not candidates for alias
expansion: it is still possible to declare any of them as an alias, but
the alias will never be expanded. Reserved words are described in
<a href="Shell-Grammar.html#Reserved-Words">Reserved Words</a>.</p>
<p>Alias expansion takes place while text is being read; hence when this
option is set it does not take effect until the end of any function or
other piece of shell code parsed as one unit. Note this may cause
differences from other shells even when the option is in effect. For
example, when running a command with ‘<code>zsh -c</code>’, or even ‘<code>zsh -o posixaliases -c</code>’, the entire command argument is parsed as one unit, so
aliases defined within the argument are not available even in later
lines. If in doubt, avoid use of aliases in non-interactive code.</p>
<p><span id="index-POSIX_005fARGZERO"></span>
<span id="index-NO_005fPOSIX_005fARGZERO"></span>
<span id="index-POSIXARGZERO"></span>
<span id="index-NOPOSIXARGZERO"></span>
<span id="index-_00240_002c-using"></span></p>
<p><code>POSIX_ARGZERO</code></p>
<p>This option may be used to temporarily disable <code>FUNCTION_ARGZERO</code> and
thereby restore the value of <code>$0</code> to the name used to invoke the shell
(or as set by the <code>-c</code> command line option). For compatibility with
previous versions of the shell, emulations use <code>NO_FUNCTION_ARGZERO</code>
instead of <code>POSIX_ARGZERO</code>, which may result in unexpected scoping of
<code>$0</code> if the emulation mode is changed inside a function or script. To
avoid this, explicitly enable <code>POSIX_ARGZERO</code> in the <code>emulate</code> command:</p>
<div class="example">
<pre><code class="language-example">emulate sh -o POSIX_ARGZERO
</code></pre>
</div>
<p>Note that <code>NO_POSIX_ARGZERO</code> has no effect unless <code>FUNCTION_ARGZERO</code> was
already enabled upon entry to the function or script.</p>
<p><span id="index-POSIX_005fBUILTINS"></span>
<span id="index-NO_005fPOSIX_005fBUILTINS"></span>
<span id="index-POSIXBUILTINS"></span>
<span id="index-NOPOSIXBUILTINS"></span></p>
<p><code>POSIX_BUILTINS</code> &lt;K&gt; &lt;S&gt;</p>
<p>When this option is set the <code>command</code> builtin can be used to execute
shell builtin commands. Parameter assignments specified before shell
functions and special builtins are kept after the command completes
unless the special builtin is prefixed with the <code>command</code> builtin.
Special builtins are <code>.</code>, <code>:</code>, <code>break</code>, <code>continue</code>, <code>declare</code>, <code>eval</code>,
<code>exit</code>, <code>export</code>, <code>integer</code>, <code>local</code>, <code>readonly</code>, <code>return</code>, <code>set</code>,
<code>shift</code>, <code>source</code>, <code>times</code>, <code>trap</code> and <code>unset</code>.</p>
<p>In addition, various error conditions associated with the above builtins
or <code>exec</code> cause a non-interactive shell to exit and an interactive shell
to return to its top-level processing.</p>
<p>Furthermore, functions and shell builtins are not executed after an
<code>exec</code> prefix; the command to be executed must be an external command
found in the path.</p>
<p>Furthermore, the <code>getopts</code> builtin behaves in a POSIX-compatible fashion
in that the associated variable <code>OPTIND</code> is not made local to functions.</p>
<p>Moreover, the warning and special exit code from <code>[[ -o ``non_existent_option`` ]]</code> are suppressed.</p>
<p><span id="index-POSIX_005fIDENTIFIERS"></span>
<span id="index-NO_005fPOSIX_005fIDENTIFIERS"></span>
<span id="index-POSIXIDENTIFIERS"></span>
<span id="index-NOPOSIXIDENTIFIERS"></span></p>
<p><code>POSIX_IDENTIFIERS</code> &lt;K&gt; &lt;S&gt;</p>
<p>When this option is set, only the ASCII characters <code>a</code> to <code>z</code>, <code>A</code> to
<code>Z</code>, <code>0</code> to <code>9</code> and <code>_</code> may be used in identifiers (names of shell
parameters and modules).</p>
<p>In addition, setting this option limits the effect of parameter
substitution with no braces, so that the expression <code>$#</code> is treated as
the parameter <code>$#</code> even if followed by a valid parameter name. When it
is unset, zsh allows expressions of the form <code>$#``name</code> to refer to the
length of <code>$``name</code>, even for special variables, for example in
expressions such as <code>$#-</code> and <code>$#*</code>.</p>
<p>Another difference is that with the option set assignment to an unset
variable in arithmetic context causes the variable to be created as a
scalar rather than a numeric type. So after ‘<code>unset t; (( t = 3 ))</code>’.
without <code>POSIX_IDENTIFIERS</code> set <code>t</code> has integer type, while with it set
it has scalar type.</p>
<p>When the option is unset and multibyte character support is enabled
(i.e. it is compiled in and the option <code>MULTIBYTE</code> is set), then
additionally any alphanumeric characters in the local character set may
be used in identifiers. Note that scripts and functions written with
this feature are or function is parsed; setting them during execution is
not sufficient as the syntax <code>variable``=``value</code> has already been
parsed as a command rather than an assignment.</p>
<p>If multibyte character support is not compiled into the shell this
option is ignored; all octets with the top bit set may be used in
identifiers. This is non-standard but is the traditional zsh behaviour.</p>
<p><span id="index-POSIX_005fSTRINGS"></span>
<span id="index-NO_005fPOSIX_005fSTRINGS"></span>
<span id="index-POSIXSTRINGS"></span>
<span id="index-NOPOSIXSTRINGS"></span>
<span id="index-discarding-embedded-nulls-in-_0024_0027_002e_002e_002e_0027"></span>
<span id="index-embedded-nulls_002c-in-_0024_0027_002e_002e_002e_0027"></span>
<span id="index-nulls_002c-embedded-in-_0024_0027_002e_002e_002e_0027"></span></p>
<p><code>POSIX_STRINGS</code> &lt;K&gt; &lt;S&gt;</p>
<p>This option affects processing of quoted strings. Currently it only
affects the behaviour of null characters, i.e. character 0 in the</p>
<p>When this option is not set, null characters embedded within strings of
the form <code>$’``...``’</code> are treated as ordinary characters. The entire
string is maintained within the shell and output to files where
necessary, although owing to restrictions of the library interface the
string is truncated at the null character in file names, environment
variables, or in arguments to external programs.</p>
<p>When this option is set, the <code>$’``...``’</code> expression is truncated at the
null character. Note that remaining parts of the same string beyond the
termination of the quotes are not truncated.</p>
<p>For example, the command line argument <code>a$’b\0c’d</code> is treated with the
option off as the characters <code>a</code>, <code>b</code>, null, <code>c</code>, <code>d</code>, and with the
option on as the characters <code>a</code>, <code>b</code>, <code>d</code>.</p>
<p><span id="index-POSIX_005fTRAPS"></span>
<span id="index-NO_005fPOSIX_005fTRAPS"></span>
<span id="index-POSIXTRAPS"></span>
<span id="index-NOPOSIXTRAPS"></span>
<span id="index-traps_002c-on-function-exit"></span>
<span id="index-traps_002c-POSIX-compatibility"></span></p>
<p><code>POSIX_TRAPS</code> &lt;K&gt; &lt;S&gt;</p>
<p>When this option is set, the usual zsh behaviour of executing traps for
<code>EXIT</code> on exit from shell functions is suppressed. In that case,
manipulating <code>EXIT</code> traps always alters the global trap for exiting the
shell; the <code>LOCAL_TRAPS</code> option is ignored for the <code>EXIT</code> trap.
Furthermore, a <code>return</code> statement executed in a trap with no argument
passes back from the function the value from the surrounding context,
not from code executed within the trap.</p>
<p><span id="index-SH_005fFILE_005fEXPANSION"></span>
<span id="index-NO_005fSH_005fFILE_005fEXPANSION"></span>
<span id="index-SHFILEEXPANSION"></span>
<span id="index-NOSHFILEEXPANSION"></span>
<span id="index-sh_002c-expansion-style"></span>
<span id="index-expansion-style_002c-sh"></span></p>
<p><code>SH_FILE_EXPANSION</code> &lt;K&gt; &lt;S&gt;</p>
<p>Perform filename expansion (e.g., <code>~</code> expansion) <em>before</em> parameter
expansion, command substitution, arithmetic expansion and brace
expansion. If this option is unset, it is performed <em>after</em> brace
expansion, so things like ‘<code>~$USERNAME</code>’ and ‘<code>~{pfalstad,rc}</code>’ will
work.</p>
<p><span id="index-SH_005fNULLCMD"></span>
<span id="index-NO_005fSH_005fNULLCMD"></span>
<span id="index-SHNULLCMD"></span> <span id="index-NOSHNULLCMD"></span>
<span id="index-NULLCMD_002c-ignoring-1"></span>
<span id="index-READNULLCMD_002c-ignoring-1"></span>
<span id="index-sh_002c-redirections-with-no-command"></span>
<span id="index-ksh_002c-redirections-with-no-command"></span>
<span id="index-redirections-with-no-command_002c-sh"></span>
<span id="index-redirections-with-no-command_002c-ksh"></span></p>
<p><code>SH_NULLCMD</code> &lt;K&gt; &lt;S&gt;</p>
<p>Do not use the values of <code>NULLCMD</code> and <code>READNULLCMD</code> when doing
redirections, use ‘<code>:</code>’ instead (see
<a href="Redirection.html#Redirection">Redirection</a>).</p>
<p><span id="index-SH_005fOPTION_005fLETTERS"></span>
<span id="index-NO_005fSH_005fOPTION_005fLETTERS"></span>
<span id="index-SHOPTIONLETTERS"></span>
<span id="index-NOSHOPTIONLETTERS"></span>
<span id="index-sh_002c-single-letter-options-style"></span>
<span id="index-ksh_002c-single-letter-options-style"></span>
<span id="index-single-letter-options_002c-ksh-style"></span>
<span id="index-options_002c-single-letter_002c-ksh-style"></span></p>
<p><code>SH_OPTION_LETTERS</code> &lt;K&gt; &lt;S&gt;</p>
<p>If this option is set the shell tries to interpret single letter options
(which are used with <code>set</code> and <code>setopt</code>) like ksh does. This also
affects the value of the <code>-</code> special parameter.</p>
<p><span id="index-SH_005fWORD_005fSPLIT"></span>
<span id="index-NO_005fSH_005fWORD_005fSPLIT"></span>
<span id="index-SHWORDSPLIT"></span>
<span id="index-NOSHWORDSPLIT"></span>
<span id="index-field-splitting_002c-sh-style"></span>
<span id="index-sh_002c-field-splitting-style"></span></p>
<p><code>SH_WORD_SPLIT</code> (<code>-y</code>) &lt;K&gt; &lt;S&gt;</p>
<p>Causes field splitting to be performed on unquoted parameter expansions.
Note that this option has nothing to do with word splitting. (See
<a href="Expansion.html#Parameter-Expansion">Parameter Expansion</a>.)</p>
<p><span id="index-TRAPS_005fASYNC"></span>
<span id="index-NO_005fTRAPS_005fASYNC"></span>
<span id="index-TRAPSASYNC"></span>
<span id="index-NOTRAPSASYNC"></span>
<span id="index-traps_002c-asynchronous"></span></p>
<p><code>TRAPS_ASYNC</code></p>
<p>While waiting for a program to exit, handle signals and run traps
immediately. Otherwise the trap is run after a child process has exited.
Note this does not affect the point at which traps are run for any case
other than when the shell is waiting for a child process.</p>
<hr />
<p><span id="Shell-State"></span></p>
<h3 id="16211-shell-state"><a class="header" href="#16211-shell-state">16.2.11 Shell State</a></h3>
<p><span id="index-INTERACTIVE"></span>
<span id="index-NO_005fINTERACTIVE"></span>
<span id="index-NOINTERACTIVE"></span></p>
<p><code>INTERACTIVE</code> (<code>-i</code>, ksh: <code>-i</code>)</p>
<p>This is an interactive shell. This option is set upon initialisation if
the standard input is a tty and commands are being read from standard
input. (See the discussion of <code>SHIN_STDIN</code>.) This heuristic may be
overridden by specifying a state for this option on the command line.
The value of this option can only be changed via flags supplied at
invocation of the shell. It cannot be changed once zsh is running.</p>
<p><span id="index-LOGIN"></span> <span id="index-NO_005fLOGIN"></span>
<span id="index-NOLOGIN"></span></p>
<p><code>LOGIN</code> (<code>-l</code>, ksh: <code>-l</code>)</p>
<p>This is a login shell. If this option is not explicitly set, the shell
becomes a login shell if the first character of the <code>argv[0]</code> passed to
the shell is a ‘<code>-</code>’.</p>
<p><span id="index-PRIVILEGED"></span>
<span id="index-NO_005fPRIVILEGED"></span>
<span id="index-NOPRIVILEGED"></span>
<span id="index-privileged-mode"></span>
<span id="index-mode_002c-privileged"></span></p>
<p><code>PRIVILEGED</code> (<code>-p</code>, ksh: <code>-p</code>)</p>
<p>Turn on privileged mode. Typically this is used when script is to be run
with elevated privileges. This should be done as follows directly with
the <code>-p</code> option to zsh so that it takes effect during startup.</p>
<div class="example">
<pre><code class="language-example">#!/bin/zsh -p
</code></pre>
</div>
<p>The option is enabled automatically on startup if the effective user
(group) ID is not equal to the real user (group) ID. In this case,
turning the option off causes the effective user and group IDs to be set
to the real user and group IDs. Be aware that if that fails the shell
may be running with different IDs than was intended so a script should
check for failure and act accordingly, for example:</p>
<div class="example">
<pre><code class="language-example">unsetopt privileged || exit
</code></pre>
</div>
<p>The <code>PRIVILEGED</code> option disables sourcing user startup files. If zsh is
invoked as ‘<code>sh</code>’ or ‘<code>ksh</code>’ with this option set, <code>/etc/suid_profile</code>
is sourced (after <code>/etc/profile</code> on interactive shells). Sourcing
<code>~/.profile</code> is disabled and the contents of the <code>ENV</code> variable is
ignored. This option cannot be changed using the <code>-m</code> option of <code>setopt</code>
and <code>unsetopt</code>, and changing it inside a function always changes it
globally regardless of the <code>LOCAL_OPTIONS</code> option.</p>
<p><span id="index-RESTRICTED-1"></span>
<span id="index-NO_005fRESTRICTED"></span>
<span id="index-NORESTRICTED"></span>
<span id="index-restricted-shell-1"></span></p>
<p><code>RESTRICTED</code> (<code>-r</code>)</p>
<p>Enables restricted mode. This option cannot be changed using <code>unsetopt</code>,
and setting it inside a function always changes it globally regardless
of the <code>LOCAL_OPTIONS</code> option. See <a href="Invocation.html#Restricted-Shell">Restricted
Shell</a>.</p>
<p><span id="index-SHIN_005fSTDIN"></span>
<span id="index-NO_005fSHIN_005fSTDIN"></span>
<span id="index-SHINSTDIN"></span> <span id="index-NOSHINSTDIN"></span></p>
<p><code>SHIN_STDIN</code> (<code>-s</code>, ksh: <code>-s</code>)</p>
<p>Commands are being read from the standard input. Commands are read from
standard input if no command is specified with <code>-c</code> and no file of
commands is specified. If <code>SHIN_STDIN</code> is set explicitly on the command
line, any argument that would otherwise have been taken as a file to run
will instead be treated as a normal positional parameter. Note that
setting or unsetting this option on the command line does not
necessarily affect the state the option will have while the shell is
running - that is purely an indicator of whether or not commands are
<em>actually</em> being read from standard input. The value of this option can
only be changed via flags supplied at invocation of the shell. It cannot
be changed once zsh is running.</p>
<p><span id="index-SINGLE_005fCOMMAND"></span>
<span id="index-NO_005fSINGLE_005fCOMMAND"></span>
<span id="index-SINGLECOMMAND"></span>
<span id="index-NOSINGLECOMMAND"></span>
<span id="index-single-command"></span>
<span id="index-INTERACTIVE_002c-use-of"></span></p>
<p><code>SINGLE_COMMAND</code> (<code>-t</code>, ksh: <code>-t</code>)</p>
<p>If the shell is reading from standard input, it exits after a single
command has been executed. This also makes the shell non-interactive,
unless the <code>INTERACTIVE</code> option is explicitly set on the command line.
The value of this option can only be changed via flags supplied at
invocation of the shell. It cannot be changed once zsh is running.</p>
<hr />
<p><span id="Zle"></span></p>
<h3 id="16212-zle"><a class="header" href="#16212-zle">16.2.12 Zle</a></h3>
<p><span id="index-BEEP"></span> <span id="index-NO_005fBEEP"></span>
<span id="index-NOBEEP"></span>
<span id="index-beep_002c-enabling"></span>
<span id="index-enabling-the-beep"></span></p>
<p><code>BEEP</code> (<code>+B</code>) &lt;D&gt;</p>
<p>Beep on error in ZLE.</p>
<p><span id="index-COMBINING_005fCHARS"></span>
<span id="index-NO_005fCOMBINING_005fCHARS"></span>
<span id="index-COMBININGCHARS"></span>
<span id="index-NOCOMBININGCHARS"></span>
<span id="index-characters_002c-_0028Unicode_0029-combining"></span>
<span id="index-combining-characters-_0028Unicode_0029"></span>
<span id="index-Unicode-combining-characters"></span></p>
<p><code>COMBINING_CHARS</code></p>
<p>Assume that the terminal displays combining characters correctly.
Specifically, if a base alphanumeric character is followed by one or
more zero-width punctuation characters, assume that the zero-width
characters will be displayed as modifications to the base character
within the same width. Not all terminals handle this. If this option is
not set, zero-width characters are displayed separately with special
mark-up.</p>
<p>If this option is set, the pattern test <code>[[:WORD:]]</code> matches a
zero-width punctuation character on the assumption that it will be used
as part of a word in combination with a word character. Otherwise the
base shell does not handle combining characters specially.</p>
<p><span id="index-EMACS"></span> <span id="index-NO_005fEMACS"></span>
<span id="index-NOEMACS"></span></p>
<p><code>EMACS</code></p>
<p>If ZLE is loaded, turning on this option has the equivalent effect of
‘<code>bindkey -e</code>’. In addition, the VI option is unset. Turning it off
has no effect. The option setting is not guaranteed to reflect the
current keymap. This option is provided for compatibility; <code>bindkey</code> is
the recommended interface.</p>
<p><span id="index-OVERSTRIKE"></span>
<span id="index-NO_005fOVERSTRIKE"></span>
<span id="index-NOOVERSTRIKE"></span>
<span id="index-editor_002c-overstrike-mode"></span>
<span id="index-overstrike-mode_002c-of-editor"></span></p>
<p><code>OVERSTRIKE</code></p>
<p>Start up the line editor in overstrike mode.</p>
<p><span id="index-SINGLE_005fLINE_005fZLE"></span>
<span id="index-NO_005fSINGLE_005fLINE_005fZLE"></span>
<span id="index-SINGLELINEZLE"></span>
<span id="index-NOSINGLELINEZLE"></span>
<span id="index-editor_002c-single-line-mode"></span></p>
<p><code>SINGLE_LINE_ZLE</code> (<code>-M</code>) &lt;K&gt;</p>
<p>Use single-line command line editing instead of multi-line.</p>
<p>Note that although this is on by default in ksh emulation it only
provides superficial compatibility with the ksh line editor and reduces
the effectiveness of the zsh line editor. As it has no effect on shell
syntax, many users may wish to disable this option when using ksh
emulation interactively.</p>
<p><span id="index-VI"></span> <span id="index-NO_005fVI"></span>
<span id="index-NOVI"></span></p>
<p><code>VI</code></p>
<p>If ZLE is loaded, turning on this option has the equivalent effect of
‘<code>bindkey -v</code>’. In addition, the EMACS option is unset. Turning it off
has no effect. The option setting is not guaranteed to reflect the
current keymap. This option is provided for compatibility; <code>bindkey</code> is
the recommended interface.</p>
<p><span id="index-ZLE"></span> <span id="index-NO_005fZLE"></span>
<span id="index-NOZLE"></span>
<span id="index-editor_002c-enabling"></span>
<span id="index-enabling-the-editor"></span></p>
<p><code>ZLE</code> (<code>-Z</code>)</p>
<p>Use the zsh line editor. Set by default in interactive shells connected
to a terminal.</p>
<hr />
<p><span id="Option-Aliases"></span> <span id="Option-Aliases-1"></span></p>
<h2 id="163-option-aliases"><a class="header" href="#163-option-aliases">16.3 Option Aliases</a></h2>
<p><span id="index-options_002c-aliases"></span></p>
<p>Some options have alternative names. These aliases are never used for
output, but can be used just like normal option names when specifying
options to the shell.</p>
<p><span id="index-BRACE_005fEXPAND"></span>
<span id="index-NO_005fBRACE_005fEXPAND"></span>
<span id="index-BRACEEXPAND"></span>
<span id="index-NOBRACEEXPAND"></span></p>
<p><code>BRACE_EXPAND</code></p>
<p><em>NO_</em><code>IGNORE_BRACES</code> (ksh and bash compatibility)</p>
<p><span id="index-DOT_005fGLOB"></span>
<span id="index-NO_005fDOT_005fGLOB"></span>
<span id="index-DOTGLOB"></span> <span id="index-NODOTGLOB"></span></p>
<p><code>DOT_GLOB</code></p>
<p><code>GLOB_DOTS</code> (bash compatibility)</p>
<p><span id="index-HASH_005fALL"></span>
<span id="index-NO_005fHASH_005fALL"></span>
<span id="index-HASHALL"></span> <span id="index-NOHASHALL"></span></p>
<p><code>HASH_ALL</code></p>
<p><code>HASH_CMDS</code> (bash compatibility)</p>
<p><span id="index-HIST_005fAPPEND"></span>
<span id="index-NO_005fHIST_005fAPPEND"></span>
<span id="index-HISTAPPEND"></span>
<span id="index-NOHISTAPPEND"></span></p>
<p><code>HIST_APPEND</code></p>
<p><code>APPEND_HISTORY</code> (bash compatibility)</p>
<p><span id="index-HIST_005fEXPAND"></span>
<span id="index-NO_005fHIST_005fEXPAND"></span>
<span id="index-HISTEXPAND"></span>
<span id="index-NOHISTEXPAND"></span></p>
<p><code>HIST_EXPAND</code></p>
<p><code>BANG_HIST</code> (bash compatibility)</p>
<p><span id="index-LOG"></span> <span id="index-NO_005fLOG"></span>
<span id="index-NOLOG"></span></p>
<p><code>LOG</code></p>
<p><em>NO_</em><code>HIST_NO_FUNCTIONS</code> (ksh compatibility)</p>
<p><span id="index-MAIL_005fWARN"></span>
<span id="index-NO_005fMAIL_005fWARN"></span>
<span id="index-MAILWARN"></span> <span id="index-NOMAILWARN"></span></p>
<p><code>MAIL_WARN</code></p>
<p><code>MAIL_WARNING</code> (bash compatibility)</p>
<p><span id="index-ONE_005fCMD"></span>
<span id="index-NO_005fONE_005fCMD"></span>
<span id="index-ONECMD"></span> <span id="index-NOONECMD"></span></p>
<p><code>ONE_CMD</code></p>
<p><code>SINGLE_COMMAND</code> (bash compatibility)</p>
<p><span id="index-PHYSICAL"></span>
<span id="index-NO_005fPHYSICAL"></span>
<span id="index-NOPHYSICAL"></span></p>
<p><code>PHYSICAL</code></p>
<p><code>CHASE_LINKS</code> (ksh and bash compatibility)</p>
<p><span id="index-PROMPT_005fVARS"></span>
<span id="index-NO_005fPROMPT_005fVARS"></span>
<span id="index-PROMPTVARS"></span>
<span id="index-NOPROMPTVARS"></span></p>
<p><code>PROMPT_VARS</code></p>
<p><code>PROMPT_SUBST</code> (bash compatibility)</p>
<p><span id="index-STDIN"></span> <span id="index-NO_005fSTDIN"></span>
<span id="index-NOSTDIN"></span></p>
<p><code>STDIN</code></p>
<p><code>SHIN_STDIN</code> (ksh compatibility)</p>
<p><span id="index-TRACK_005fALL"></span>
<span id="index-NO_005fTRACK_005fALL"></span>
<span id="index-TRACKALL"></span> <span id="index-NOTRACKALL"></span></p>
<p><code>TRACK_ALL</code></p>
<p><code>HASH_CMDS</code> (ksh compatibility)</p>
<hr />
<p><span id="Single-Letter-Options"></span>
<span id="Single-Letter-Options-1"></span></p>
<h2 id="164-single-letter-options"><a class="header" href="#164-single-letter-options">16.4 Single Letter Options</a></h2>
<p><span id="index-options_002c-single-letter"></span>
<span id="index-single-letter-options"></span></p>
<hr />
<p><span id="Default-set"></span></p>
<h3 id="1641-default-set"><a class="header" href="#1641-default-set">16.4.1 Default set</a></h3>
<ul>
<li>
<p><code>-0</code><br />
CORRECT</p>
</li>
<li>
<p><code>-1</code><br />
PRINT_EXIT_VALUE</p>
</li>
<li>
<p><code>-2</code><br />
*NO_*BAD_PATTERN</p>
</li>
<li>
<p><code>-3</code><br />
*NO_*NOMATCH</p>
</li>
<li>
<p><code>-4</code><br />
GLOB_DOTS</p>
</li>
<li>
<p><code>-5</code><br />
NOTIFY</p>
</li>
<li>
<p><code>-6</code><br />
BG_NICE</p>
</li>
<li>
<p><code>-7</code><br />
IGNORE_EOF</p>
</li>
<li>
<p><code>-8</code><br />
MARK_DIRS</p>
</li>
<li>
<p><code>-9</code><br />
AUTO_LIST</p>
</li>
<li>
<p><code>-B</code><br />
*NO_*BEEP</p>
</li>
<li>
<p><code>-C</code><br />
*NO_*CLOBBER</p>
</li>
<li>
<p><code>-D</code><br />
PUSHD_TO_HOME</p>
</li>
<li>
<p><code>-E</code><br />
PUSHD_SILENT</p>
</li>
<li>
<p><code>-F</code><br />
*NO_*GLOB</p>
</li>
<li>
<p><code>-G</code><br />
NULL_GLOB</p>
</li>
<li>
<p><code>-H</code><br />
RM_STAR_SILENT</p>
</li>
<li>
<p><code>-I</code><br />
IGNORE_BRACES</p>
</li>
<li>
<p><code>-J</code><br />
AUTO_CD</p>
</li>
<li>
<p><code>-K</code><br />
*NO_*BANG_HIST</p>
</li>
<li>
<p><code>-L</code><br />
SUN_KEYBOARD_HACK</p>
</li>
<li>
<p><code>-M</code><br />
SINGLE_LINE_ZLE</p>
</li>
<li>
<p><code>-N</code><br />
AUTO_PUSHD</p>
</li>
<li>
<p><code>-O</code><br />
CORRECT_ALL</p>
</li>
<li>
<p><code>-P</code><br />
RC_EXPAND_PARAM</p>
</li>
<li>
<p><code>-Q</code><br />
PATH_DIRS</p>
</li>
<li>
<p><code>-R</code><br />
LONG_LIST_JOBS</p>
</li>
<li>
<p><code>-S</code><br />
REC_EXACT</p>
</li>
<li>
<p><code>-T</code><br />
CDABLE_VARS</p>
</li>
<li>
<p><code>-U</code><br />
MAIL_WARNING</p>
</li>
<li>
<p><code>-V</code><br />
*NO_*PROMPT_CR</p>
</li>
<li>
<p><code>-W</code><br />
AUTO_RESUME</p>
</li>
<li>
<p><code>-X</code><br />
LIST_TYPES</p>
</li>
<li>
<p><code>-Y</code><br />
MENU_COMPLETE</p>
</li>
<li>
<p><code>-Z</code><br />
ZLE</p>
</li>
<li>
<p><code>-a</code><br />
ALL_EXPORT</p>
</li>
<li>
<p><code>-e</code><br />
ERR_EXIT</p>
</li>
<li>
<p><code>-f</code><br />
*NO_*RCS</p>
</li>
<li>
<p><code>-g</code><br />
HIST_IGNORE_SPACE</p>
</li>
<li>
<p><code>-h</code><br />
HIST_IGNORE_DUPS</p>
</li>
<li>
<p><code>-i</code><br />
INTERACTIVE</p>
</li>
<li>
<p><code>-k</code><br />
INTERACTIVE_COMMENTS</p>
</li>
<li>
<p><code>-l</code><br />
LOGIN</p>
</li>
<li>
<p><code>-m</code><br />
MONITOR</p>
</li>
<li>
<p><code>-n</code><br />
*NO_*EXEC</p>
</li>
<li>
<p><code>-p</code><br />
PRIVILEGED</p>
</li>
<li>
<p><code>-r</code><br />
RESTRICTED</p>
</li>
<li>
<p><code>-s</code><br />
SHIN_STDIN</p>
</li>
<li>
<p><code>-t</code><br />
SINGLE_COMMAND</p>
</li>
<li>
<p><code>-u</code><br />
*NO_*UNSET</p>
</li>
<li>
<p><code>-v</code><br />
VERBOSE</p>
</li>
<li>
<p><code>-w</code><br />
CHASE_LINKS</p>
</li>
<li>
<p><code>-x</code><br />
XTRACE</p>
</li>
<li>
<p><code>-y</code><br />
SH_WORD_SPLIT</p>
</li>
</ul>
<hr />
<p><span id="sh_002fksh-emulation-set"></span></p>
<h3 id="1642-shksh-emulation-set"><a class="header" href="#1642-shksh-emulation-set">16.4.2 sh/ksh emulation set</a></h3>
<ul>
<li>
<p><code>-C</code><br />
*NO_*CLOBBER</p>
</li>
<li>
<p><code>-T</code><br />
TRAPS_ASYNC</p>
</li>
<li>
<p><code>-X</code><br />
MARK_DIRS</p>
</li>
<li>
<p><code>-a</code><br />
ALL_EXPORT</p>
</li>
<li>
<p><code>-b</code><br />
NOTIFY</p>
</li>
<li>
<p><code>-e</code><br />
ERR_EXIT</p>
</li>
<li>
<p><code>-f</code><br />
*NO_*GLOB</p>
</li>
<li>
<p><code>-i</code><br />
INTERACTIVE</p>
</li>
<li>
<p><code>-l</code><br />
LOGIN</p>
</li>
<li>
<p><code>-m</code><br />
MONITOR</p>
</li>
<li>
<p><code>-n</code><br />
*NO_*EXEC</p>
</li>
<li>
<p><code>-p</code><br />
PRIVILEGED</p>
</li>
<li>
<p><code>-r</code><br />
RESTRICTED</p>
</li>
<li>
<p><code>-s</code><br />
SHIN_STDIN</p>
</li>
<li>
<p><code>-t</code><br />
SINGLE_COMMAND</p>
</li>
<li>
<p><code>-u</code><br />
*NO_*UNSET</p>
</li>
<li>
<p><code>-v</code><br />
VERBOSE</p>
</li>
<li>
<p><code>-x</code><br />
XTRACE</p>
</li>
</ul>
<hr />
<p><span id="Also-note"></span></p>
<h3 id="1643-also-note"><a class="header" href="#1643-also-note">16.4.3 Also note</a></h3>
<ul>
<li>
<p><code>-A</code><br />
Used by <code>set</code> for setting arrays</p>
</li>
<li>
<p><code>-b</code><br />
Used on the command line to specify end of option processing</p>
</li>
<li>
<p><code>-c</code><br />
Used on the command line to specify a single command</p>
</li>
<li>
<p><code>-m</code><br />
Used by <code>setopt</code> for pattern-matching option setting</p>
</li>
<li>
<p><code>-o</code><br />
Used in all places to allow use of long option names</p>
</li>
<li>
<p><code>-s</code><br />
Used by <code>set</code> to sort positional parameters</p>
</li>
</ul>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Shell-Builtin-Commands.html#17-shell-builtin-commands">17 Shell Builtin Commands</a></li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Shell-Builtin-Commands"></span>
<span id="Shell-Builtin-Commands-1"></span></p>
<h1 id="17-shell-builtin-commands"><a class="header" href="#17-shell-builtin-commands">17 Shell Builtin Commands</a></h1>
<p><span id="index-builtin-commands"></span>
<span id="index-commands_002c-builtin"></span></p>
<p>Some shell builtin commands take options as described in individual
entries; these are often referred to in the list below as ‘<code>flags</code>’ to
avoid confusion with shell options, which may also have an effect on the
behaviour of builtin commands. In this introductory section, ‘<code>option</code>’
always has the meaning of an option to a command that should be familiar
to most command line users.</p>
<p>Typically, options are single letters preceded by a hyphen (<code>-</code>).
Options that take an argument accept it either immediately following the
option letter or after white space, for example ‘<code>print -C3 {1..9}</code>’ or
‘<code>print -C 3 {1..9}</code>’ are equivalent. Arguments to options are not the
same as arguments to the command; the documentation indicates which is
which. Options that do not take an argument may be combined in a single
word, for example ‘<code>print -rca – *</code>’ and ‘<code>print -r -c -a – *</code>’ are
equivalent.</p>
<p>Some shell builtin commands also take options that begin with ‘<code>+</code>’
instead of ‘<code>-</code>’. The list below makes clear which commands these are.</p>
<p>Options (together with their individual arguments, if any) must appear
in a group before any non-option arguments; once the first non-option
argument has been found, option processing is terminated.</p>
<p>All builtin commands other than ‘<code>echo</code>’ and precommand modifiers, even
those that have no options, can be given the argument ‘<code>-``-</code>’ to
terminate option processing. This indicates that the following words are
non-option arguments, but is otherwise ignored. This is useful in cases
where arguments to the command may begin with ‘<code>-</code>’. For historical
reasons, most builtin commands (including ‘<code>echo</code>’) also recognize a
single ‘<code>-</code>’ in a separate word for this purpose; note that this is less
standard and use of ‘<code>-``-</code>’ is recommended.</p>
<ul>
<li>
<p><code>-</code> <code>simple command</code><br />
See <a href="Shell-Grammar.html#Precommand-Modifiers">Precommand Modifiers</a>.</p>
<p><span id="index-_002e"></span></p>
</li>
<li>
<p><code>.</code> <code>file</code> [ <code>arg</code> ... ]<br />
Read commands from <code>file</code> and execute them in the current shell
environment.</p>
<p>If <code>file</code> does not contain a slash, or if <code>PATH_DIRS</code> is set, the
shell looks in the components of <code>$path</code> to find the directory
containing <code>file</code>. Files in the current directory are not read
unless ‘<code>.</code>’ appears somewhere in <code>$path</code>. If a file named
‘<code>file``.zwc</code>’ is found, is newer than <code>file</code>, and is the compiled
form (created with the <code>zcompile</code> builtin) of <code>file</code>, then commands
are read from that file instead of <code>file</code>.</p>
<p>If any arguments <code>arg</code> are given, they become the positional
parameters; the old positional parameters are restored when the
<code>file</code> is done executing. However, if no arguments are given, the
positional parameters remain those of the calling context, and no
restoring is done.</p>
<p>If <code>file</code> was not found the return status is 127; if <code>file</code> was
found but contained a syntax error the return status is 126; else
the return status is the exit status of the last command executed.</p>
<p><span id="index-_003a"></span>
<span id="index-expanding-parameters"></span>
<span id="index-parameters_002c-expanding"></span>
<span id="index-doing-nothing"></span></p>
</li>
<li>
<p><code>:</code> [ <code>arg</code> ... ]<br />
This command does nothing, although normal argument expansions is
performed which may have effects on shell parameters. A zero exit
status is returned.</p>
<p><span id="index-alias"></span>
<span id="index-aliases_002c-defining"></span>
<span id="index-aliases_002c-listing"></span></p>
</li>
<li>
<p><code>alias</code> [ {<code>+</code>|<code>-</code>}<code>gmrsL</code> ] [ <code>name</code>[<code>=``value</code>] ... ]<br />
For each <code>name</code> with a corresponding <code>value</code>, define an alias with
that value. A trailing space in <code>value</code> causes the next word to be
checked for alias expansion. If the <code>-g</code> flag is present, define a
global alias; global aliases are expanded even if they do not occur
in command position.</p>
<p>If the <code>-s</code> flag is present, define a suffix alias: if the command
word on a command line is in the form ‘<code>text``.``name</code>’, where
<code>text</code> is any non-empty string, it is replaced by the text ‘<code>value</code>
<code>text``.``name</code>’. Note that <code>name</code> is treated as a literal string,
not a pattern. A trailing space in <code>value</code> is not special in this
case. For example,</p>
<div class="example">
<pre><code class="language-example">alias -s ps='gv --'
</code></pre>
</div>
<p>will cause the command ‘<code>*.ps</code>’ to be expanded to ‘<code>gv – *.ps</code>’. As
alias expansion is carried out earlier than globbing, the ‘<code>*.ps</code>’
will then be expanded. Suffix aliases constitute a different name
space from other aliases (so in the above example it is still
possible to create an alias for the command <code>ps</code>) and the two sets
are never listed together.</p>
<p>For each <code>name</code> with no <code>value</code>, print the value of <code>name</code>, if any.
With no arguments, print all currently defined aliases other than
suffix aliases. If the <code>-m</code> flag is given the arguments are taken as
patterns (they should be quoted to preserve them from being
interpreted as glob patterns), and the aliases matching these
patterns are printed. When printing aliases and one of the <code>-g</code>,
<code>-r</code> or <code>-s</code> flags is present, restrict the printing to global,
regular or suffix aliases, respectively; a regular alias is one
which is neither a global nor a suffix alias. Using ‘<code>+</code>’ instead of
‘<code>-</code>’, or ending the option list with a single ‘<code>+</code>’, prevents the
values of the aliases from being printed.</p>
<p>If the <code>-L</code> flag is present, then print each status is nonzero if a
<code>name</code> (with no <code>value</code>) is given for which no alias has been
defined.</p>
<p>For more on aliases, include common problems, see
<a href="Shell-Grammar.html#Aliasing">Aliasing</a>.</p>
<p><span id="index-autoload"></span>
<span id="index-functions_002c-autoloading-1"></span>
<span id="index-autoloading-functions-1"></span></p>
</li>
<li>
<p><code>autoload</code> [ {<code>+</code>|<code>-</code>}<code>RTUXdkmrtWz</code> ] [ <code>-w</code> ] [ <code>name</code> ...
]<br />
<span id="index-fpath_002c-searching"></span></p>
<p>See the section ‘Autoloading Functions’ in
<a href="Functions.html#Functions">Functions</a> for full details. The <code>fpath</code>
parameter will be searched to find the function definition when the
function is first referenced.</p>
<p>If <code>name</code> consists of an absolute path, the function is defined to
load from the file given (searching as usual for dump files in the
given location). The name of the function is the basename
(non-directory part) of the file. It is normally an error if the
function is not found in the given location; however, if the option
<code>-d</code> is given, searching for the function defaults to <code>$fpath</code>. If a
function is loaded by absolute path, any functions loaded from it
that are marked for <code>autoload</code> without an absolute path have the
load path of the parent function temporarily prepended to <code>$fpath</code>.</p>
<p>If the option <code>-r</code> or <code>-R</code> is given, the function is searched for
immediately and the location is recorded internally for use when the
function is executed; a relative path is expanded using the value of
<code>$PWD</code>. This protects against a change to <code>$fpath</code> after the call to
<code>autoload</code>. With <code>-r</code>, if the function is not found, it is silently
left unresolved until execution; with <code>-R</code>, an error message is
printed and command processing aborted immediately the search fails,
i.e. at the <code>autoload</code> command rather than at function execution..</p>
<p>The flag <code>-X</code> may be used only inside a shell function. It causes
the calling function to be marked for autoloading and then
immediately loaded and executed, with the current array of
positional parameters as arguments. This replaces the previous
definition of the function. If no function definition is found, an
error is printed and the function remains undefined and marked for
autoloading. If an argument is given, it is used as a directory
(i.e. it does not include the name of the function) in which the
function is to be found; this may be combined with the <code>-d</code> option
to allow the function search to default to <code>$fpath</code> if it is not in
the given location.</p>
<p>The flag <code>+X</code> attempts to load each <code>name</code> as an autoloaded
function, but does <em>not</em> execute it. The exit status is zero
(success) if the function was not previously defined <em>and</em> a
definition for it was found. This does <em>not</em> replace any existing
definition of the function. The exit status is nonzero (failure) if
the function was already defined or when no definition was found. In
the latter case the function remains undefined and marked for
autoloading. If ksh-style autoloading is enabled, the function
created will contain the contents of the file plus a call to the
function itself appended to it, thus giving normal ksh autoloading
behaviour on the first call to the function. If the <code>-m</code> flag is
also given each <code>name</code> is treated as a pattern and all functions
already marked for autoload that match the pattern are loaded.</p>
<p>With the <code>-t</code> flag, turn on execution tracing; with <code>-T</code>, turn on
execution tracing only for the current function, turning it off on
entry to any called functions that do not also have tracing enabled.</p>
<p>With the <code>-U</code> flag, alias expansion is suppressed when the function
is loaded.</p>
<p>With the <code>-w</code> flag, the <code>name</code>s are taken as names of files compiled
with the <code>zcompile</code> builtin, and all functions defined in them are
marked for autoloading.</p>
<p>The flags <code>-z</code> and <code>-k</code> mark the function to be autoloaded using the
zsh or ksh style, as if the option <code>KSH_AUTOLOAD</code> were unset or were
set, respectively. The flags override the setting of the option at
the time the function is loaded.</p>
<p>Note that the <code>autoload</code> command makes no attempt to ensure the
shell options set during the loading or execution of the file have
any particular value. For this, the <code>emulate</code> command can be used:</p>
<div class="example">
<pre><code class="language-example">emulate zsh -c 'autoload -Uz func'
</code></pre>
</div>
<p>arranges that when <code>func</code> is loaded the shell is in native <code>zsh</code>
emulation, and this emulation is also applied when <code>func</code> is run.</p>
<p>Some of the functions of <code>autoload</code> are also provided by <code>functions -u</code> or <code>functions -U</code>, but <code>autoload</code> is a more comprehensive
interface.</p>
<p><span id="index-bg"></span>
<span id="index-jobs_002c-backgrounding"></span></p>
</li>
<li>
<p><code>bg</code> [ <code>job</code> ... ]<br />
<code>job</code> ... <code>&amp;</code><br />
Put each specified <code>job</code> in the background, or the current job if
none is specified.</p>
</li>
<li>
<p><code>bindkey</code><br />
See <a href="Zsh-Line-Editor.html#Zle-Builtins">Zle Builtins</a>.</p>
<p><span id="index-break"></span>
<span id="index-exiting-loops"></span>
<span id="index-loops_002c-exiting"></span></p>
</li>
<li>
<p><code>break</code> [ <code>n</code> ]<br />
Exit from an enclosing <code>for</code>, <code>while</code>, <code>until</code>, <code>select</code> or <code>repeat</code>
loop. If an arithmetic expression <code>n</code> is specified, then break <code>n</code>
levels instead of just one.</p>
<p><span id="index-builtin-1"></span></p>
</li>
<li>
<p><code>builtin</code> <code>name</code> [ <code>args</code> ... ]<br />
Executes the builtin <code>name</code>, with the given <code>args</code>.</p>
<p><span id="index-bye"></span></p>
</li>
<li>
<p><code>bye</code><br />
Same as <code>exit</code>.</p>
</li>
<li>
<p><code>cap</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcap-Module">The zsh/cap Module</a>.</p>
<p><span id="index-cd"></span>
<span id="index-directories_002c-changing"></span></p>
</li>
<li>
<p><code>cd</code> [ <code>-qsLP</code> ] [ <code>arg</code> ]<br />
<code>cd</code> [ <code>-qsLP</code> ] <code>old</code> <code>new</code><br />
<code>cd</code> [ <code>-qsLP</code> ] {<code>+</code>|<code>-</code>}<code>n</code><br />
Change the current directory. In the first form, change the current
directory to <code>arg</code>, or to the value of <code>$HOME</code> if <code>arg</code> is not
specified. If <code>arg</code> is ‘<code>-</code>’, change to the previous directory.</p>
<p>Otherwise, if <code>arg</code> begins with a slash, attempt to change to the
directory given by <code>arg</code>.</p>
<p>If <code>arg</code> does not begin with a slash, the behaviour depends on
whether the current directory ‘<code>.</code>’ occurs in the list of
directories contained in the shell parameter <code>cdpath</code>. If it does
not, first attempt to change to the directory <code>arg</code> under the
current directory, and if that fails but <code>cdpath</code> is set and
contains at least one element attempt to change to the directory
<code>arg</code> under each component of <code>cdpath</code> in turn until successful. If
‘<code>.</code>’ occurs in <code>cdpath</code>, then <code>cdpath</code> is searched strictly in
order so that ‘<code>.</code>’ is only tried at the appropriate point.</p>
<p>The order of testing <code>cdpath</code> is modified if the option <code>POSIX_CD</code>
is set, as described in the documentation for the option.</p>
<p>If no directory is found, the option <code>CDABLE_VARS</code> is set, and a
parameter named <code>arg</code> exists whose value begins with a slash, treat
its value as the directory. In that case, the parameter is added to
the named</p>
<p>The second form of <code>cd</code> substitutes the string <code>new</code> for the string
<code>old</code> in the name of the current directory, and tries to change to
this new directory.</p>
<p>The third form of <code>cd</code> extracts an entry from the directory stack,
and changes to that directory. An argument of the form ‘<code>+``n</code>’
identifies a stack entry by counting from the left of the list shown
by the <code>dirs</code> command, starting with zero. An argument of the form
‘<code>-``n</code>’ counts from the right. If the <code>PUSHD_MINUS</code> option is
set, the meanings of ‘<code>+</code>’ and ‘<code>-</code>’ in this context are swapped. If
the <code>POSIX_CD</code> option is set, this form of <code>cd</code> is not recognised
and will be interpreted as the first form.</p>
<p>If the <code>-q</code> (quiet) option is specified, the hook function <code>chpwd</code>
and the functions in the array <code>chpwd_functions</code> are not called.
This is useful for calls to <code>cd</code> that do not change the environment
seen by an interactive user.</p>
<p>If the <code>-s</code> option is specified, <code>cd</code> refuses to change the current
directory if the given pathname contains symlinks. If the <code>-P</code>
option is given or the <code>CHASE_LINKS</code> option is set, symbolic links
are resolved to their true values. If the <code>-L</code> option is given
symbolic links are retained in the directory (and not resolved)
regardless of the state of the <code>CHASE_LINKS</code> option.</p>
<p><span id="index-chdir"></span></p>
</li>
<li>
<p><code>chdir</code><br />
Same as <code>cd</code>.</p>
</li>
<li>
<p><code>clone</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fclone-Module">The zsh/clone
Module</a>.</p>
<p><span id="index-command-1"></span></p>
</li>
<li>
<p><code>command</code> [ <code>-pvV</code> ] <code>simple command</code><br />
The simple command argument is taken as an external command instead
of a function or builtin and is executed. If the <code>POSIX_BUILTINS</code>
option is set, builtins will also be executed but certain special
properties of them are suppressed. The <code>-p</code> flag causes a default
path to be searched instead of that in <code>$path</code>. With the <code>-v</code> flag,
<code>command</code> is similar to <code>whence</code> and with <code>-V</code>, it is equivalent to
<code>whence -v</code>.</p>
<p>See also <a href="Shell-Grammar.html#Precommand-Modifiers">Precommand
Modifiers</a>.</p>
</li>
<li>
<p><code>comparguments</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
</li>
<li>
<p><code>compcall</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcompctl-Module">The zsh/compctl
Module</a>.</p>
</li>
<li>
<p><code>compctl</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcompctl-Module">The zsh/compctl
Module</a>.</p>
</li>
<li>
<p><code>compdescribe</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
</li>
<li>
<p><code>compfiles</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
</li>
<li>
<p><code>compgroups</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
</li>
<li>
<p><code>compquote</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
</li>
<li>
<p><code>comptags</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
</li>
<li>
<p><code>comptry</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
</li>
<li>
<p><code>compvalues</code><br />
See <a href="Zsh-Modules.html#The-zsh_002fcomputil-Module">The zsh/computil
Module</a>.</p>
<p><span id="index-continue"></span>
<span id="index-loops_002c-continuing"></span>
<span id="index-continuing-loops"></span></p>
</li>
<li>
<p><code>continue</code> [ <code>n</code> ]<br />
Resume the next iteration of the enclosing <code>for</code>, <code>while</code>, <code>until</code>,
<code>select</code> or <code>repeat</code> loop. If an arithmetic expression <code>n</code> is
specified, break out of <code>n</code>-1 loops and resume at the <code>n</code>th
enclosing loop.</p>
<p><span id="index-declare"></span></p>
</li>
<li>
<p><code>declare</code><br />
Same as <code>typeset</code>.</p>
<p><span id="index-dirs"></span>
<span id="index-directory-stack_002c-printing"></span></p>
</li>
<li>
<p><code>dirs</code> [ <code>-c</code> ] [ <code>arg</code> ... ]<br />
<code>dirs</code> [ <code>-lpv</code> ]<br />
With no arguments, print the contents of the directory stack.
Directories are added to this stack with the <code>pushd</code> command, and
removed with the <code>cd</code> or <code>popd</code> commands. If arguments are
specified, load them onto the directory stack, replacing anything
that was there, and push the current directory onto the stack.</p>
<ul>
<li>
<p><code>-c</code><br />
clear the directory stack.</p>
</li>
<li>
<p><code>-l</code><br />
print directory names in full instead of using of using <code>~</code>
expressions (<a href="Expansion.html#Filename-Expansion">Filename
Expansion</a>).</p>
</li>
<li>
<p><code>-p</code><br />
print directory entries one per line.</p>
</li>
<li>
<p><code>-v</code><br />
number the directories in the stack when printing.</p>
</li>
</ul>
<p><span id="index-disable"></span>
<span id="index-disabling-commands"></span>
<span id="index-commands_002c-disabling"></span></p>
</li>
<li>
<p><code>disable</code> [ <code>-afmprs</code> ] <code>name</code> ...<br />
<code>’?’</code><br />
The pattern character <code>?</code> wherever it occurs, including when
preceding a parenthesis with <code>KSH_GLOB</code>.</p>
</li>
<li>
<p><code>’*’</code><br />
The pattern character <code>*</code> wherever it occurs, including recursive
globbing and when preceding a parenthesis with <code>KSH_GLOB</code>.</p>
</li>
<li>
<p><code>’[’</code><br />
Character classes.</p>
</li>
<li>
<p><code>’&lt;’</code> (<code>NO_SH_GLOB</code>)<br />
Numeric ranges.</p>
</li>
<li>
<p><code>’|’</code> (<code>NO_SH_GLOB</code>)<br />
Alternation in grouped patterns, case statements, or KSH_GLOB
parenthesised expressions.</p>
</li>
<li>
<p><code>’(’</code> (<code>NO_SH_GLOB</code>)<br />
Grouping using single parentheses. Disabling this does not disable
the use of parentheses for <code>KSH_GLOB</code> where they are introduced by a
special character, nor for glob qualifiers (use ‘<code>setopt NO_BARE_GLOB_QUAL</code>’ to disable glob qualifiers that use parentheses
only).</p>
</li>
<li>
<p><code>’~’</code> (<code>EXTENDED_GLOB</code>)<br />
Exclusion in the form <code>A``~``B</code>.</p>
</li>
<li>
<p><code>’^’</code> (<code>EXTENDED_GLOB</code>)<br />
Exclusion in the form <code>A``^``B</code>.</p>
</li>
<li>
<p><code>’#’</code> (<code>EXTENDED_GLOB</code>)<br />
The pattern character <code>#</code> wherever it occurs, both for repetition of
a previous pattern and for indicating globbing flags.</p>
</li>
<li>
<p><code>’?(’</code> (<code>KSH_GLOB</code>)<br />
The grouping form <code>?(``...``)</code>. Note this is also disabled if <code>’?’</code>
is disabled.</p>
</li>
<li>
<p><code>’*(’</code> (<code>KSH_GLOB</code>)<br />
The grouping form <code>*(``...``)</code>. Note this is also disabled if <code>’*’</code>
is disabled.</p>
</li>
<li>
<p><code>’+(’</code> (<code>KSH_GLOB</code>)<br />
The grouping form <code>+(``...``)</code>.</p>
</li>
<li>
<p><code>’!(’</code> (<code>KSH_GLOB</code>)<br />
The grouping form <code>!(``...``)</code>.</p>
</li>
<li>
<p><code>’@(’</code> (<code>KSH_GLOB</code>)<br />
The grouping form <code>@(``...``)</code>.</p>
</li>
</ul>
<p><span id="index-disown"></span>
<span id="index-jobs_002c-disowning-1"></span></p>
<p><code>disown</code> [ <code>job</code> ... ]</p>
<p><code>job</code> ... <code>&amp;|</code></p>
<p><code>job</code> ... <code>&amp;!</code></p>
<p>no longer report their status, and will not complain if you try to exit
an interactive shell with them running or stopped. If no <code>job</code> is
specified, disown the current job.</p>
<p>If the <code>job</code>s are currently stopped and the <code>AUTO_CONTINUE</code> option is
not set, a warning is printed containing information about how to make
them running after they have been disowned. If one of the latter two
forms is used, the <code>job</code>s will automatically be made running,
independent of the setting of the <code>AUTO_CONTINUE</code> option.</p>
<p><span id="index-echo"></span></p>
<p><code>echo</code> [ <code>-neE</code> ] [ <code>arg</code> ... ]</p>
<p>Write each <code>arg</code> on the standard output, with a space separating each
one. If the <code>-n</code> flag is not present, print a newline at the end. <code>echo</code>
recognizes the following escape sequences:</p>
<ul>
<li>
<p><code>\a</code><br />
bell character</p>
</li>
<li>
<p><code>\b</code><br />
backspace</p>
</li>
<li>
<p><code>\c</code><br />
suppress subsequent characters and final newline</p>
</li>
<li>
<p><code>\e</code><br />
escape</p>
</li>
<li>
<p><code>\f</code><br />
form feed</p>
</li>
<li>
<p><code>\n</code><br />
linefeed (newline)</p>
</li>
<li>
<p><code>\r</code><br />
carriage return</p>
</li>
<li>
<p><code>\t</code><br />
horizontal tab</p>
</li>
<li>
<p><code>\v</code><br />
vertical tab</p>
</li>
<li>
<p><code>\\</code><br />
backslash</p>
</li>
<li>
<p><code>\0``NNN</code><br />
character code in octal</p>
</li>
<li>
<p><code>\x``NN</code><br />
character code in hexadecimal</p>
</li>
<li>
<p><code>\u``NNNN</code><br />
unicode character code in hexadecimal</p>
</li>
<li>
<p><code>\U``NNNNNNNN</code><br />
unicode character code in hexadecimal</p>
</li>
</ul>
<p><span id="index-BSD_005fECHO_002c-use-of"></span></p>
<p>The <code>-E</code> flag, or the <code>BSD_ECHO</code> option, can be used to disable these
escape sequences. In the latter case, <code>-e</code> flag can be used to enable
them.</p>
<p>Note that for standards compliance a double dash does not terminate
option processing; instead, it is printed directly. However, a single
dash does terminate option processing, so the first dash, possibly
following options, is not printed, but everything following it is
printed as an argument. The single dash behaviour is different <code>printf</code>,
and for a more controllable way of printing text within zsh, see
<code>print</code>.</p>
<p><code>echotc</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002ftermcap-Module">The zsh/termcap
Module</a>.</p>
<p><code>echoti</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fterminfo-Module">The zsh/terminfo
Module</a>.</p>
<p><span id="index-emulate"></span>
<span id="index-compatibility_002c-sh"></span>
<span id="index-compatibility_002c-ksh"></span>
<span id="index-compatibility_002c-csh"></span>
<span id="index-sh_002c-compatibility"></span>
<span id="index-ksh_002c-compatibility"></span>
<span id="index-csh_002c-compatibility"></span></p>
<p><code>emulate</code> [ <code>-lLR</code> ] [ {<code>zsh</code>|<code>sh</code>|<code>ksh</code>|<code>csh</code>} [ <code>flags</code> ... ] ]</p>
<p>Without any argument print current emulation mode.</p>
<p>With single argument set up zsh options to emulate the specified shell
as much as possible. csh will never be fully emulated. If the argument
is not one of the shells listed above, <code>zsh</code> will be used as a default;
more precisely, the tests performed on the argument are the same as
those used to determine the emulation at startup based on the shell
name, see <a href="Invocation.html#Compatibility">Compatibility</a> . In addition
to setting shell options, the command also restores the pristine state
of pattern enables, as if all patterns had been enabled using <code>enable -p</code>.</p>
<p>If the <code>emulate</code> command occurs inside a function that has been marked
for execution tracing with <code>functions -t</code> then the <code>xtrace</code> option will
be turned on regardless of emulation mode or other options. Note that
code executed inside the function by the <code>.</code>, <code>source</code>, or <code>eval</code>
commands is not considered to be running directly from the function,
hence does not provoke this behaviour.</p>
<p>are reset to their default value corresponding to the specified
emulation mode, except for certain options describing the interactive
environment; otherwise, only those options likely to cause portability
problems in scripts and functions are altered. If the <code>-L</code> switch is
given, the options <code>LOCAL_OPTIONS</code>, <code>LOCAL_PATTERNS</code> and <code>LOCAL_TRAPS</code>
will be set as well, causing the effects of the <code>emulate</code> command and
any <code>setopt</code>, <code>disable -p</code> or <code>enable -p</code>, and <code>trap</code> commands to be
local to the immediately surrounding shell function, if any; normally
these options are turned off in all emulation modes except <code>ksh</code>. The
<code>-L</code> switch is mutually exclusive with the use of <code>-c</code> in <code>flags</code>.</p>
<p>If there is a single argument and the <code>-l</code> switch is given, the options
that would be set or unset (the latter indicated with the prefix ‘<code>no</code>’)
are listed. <code>-l</code> can be combined with <code>-L</code> or <code>-R</code> and the list will be
modified in the appropriate way. Note the list does not depend on the
current setting of options, i.e. it includes all options that may in
principle change, not just those that would actually change.</p>
<p>The <code>flags</code> may be any of the invocation-time flags described in
<a href="Invocation.html#Invocation">Invocation</a>, except that ‘<code>-o EMACS</code>’ and
‘<code>-o VI</code>’ may not be used. Flags such as ‘<code>+r</code>’/‘<code>+o RESTRICTED</code>’ may
be prohibited in some circumstances.</p>
<p>If <code>-c</code> <code>arg</code> appears in <code>flags</code>, <code>arg</code> is evaluated while the requested
emulation is temporarily in effect. In this case the emulation mode and
all options are restored to their previous values before <code>emulate</code>
returns. The <code>-R</code> switch may precede the name of the shell to emulate;
note this has a meaning distinct from including <code>-R</code> in <code>flags</code>.</p>
<p>Use of <code>-c</code> enables ‘sticky’ emulation mode for functions defined within
the evaluated expression: the emulation mode is associated thereafter
with the function so that whenever the function is executed the
emulation (respecting the <code>-R</code> switch, if present) and all options are
set (and pattern disables cleared) before entry to the function, and the
state is restored after exit. If the function is called when the sticky
emulation is already in effect, either within an ‘<code>emulate</code> <code>shell</code>
<code>-c</code>’ expression or within another function with the same sticky
emulation, entry and exit from the function do not cause options to be
altered (except due to standard processing such as the <code>LOCAL_OPTIONS</code>
option). This also applies to functions marked for autoload within the
sticky emulation; the appropriate set of options will be applied at the
point the function is loaded as well as when it is run.</p>
<p>For example:</p>
<div class="example">
<pre><code class="language-example">emulate sh -c 'fni() { setopt cshnullglob; }
fno() { fni; }'
fno
</code></pre>
</div>
<p>The two functions <code>fni</code> and <code>fno</code> are defined with sticky <code>sh</code>
emulation. <code>fno</code> is then executed, causing options associated with
emulations to be set to their values in <code>sh</code>. <code>fno</code> then calls <code>fni</code>;
because <code>fni</code> is also marked for sticky <code>sh</code> emulation, no option
changes take place on entry to or exit from it. Hence the option
<code>cshnullglob</code>, turned off by <code>sh</code> emulation, will be turned on within
<code>fni</code> and remain on return to <code>fno</code>. On exit from <code>fno</code>, the emulation
mode and all options will be restored to the state they were in before
entry to the temporary emulation.</p>
<p>The documentation above is typically sufficient for the intended
environment. More detailed rules follow.</p>
<ul>
<li>
<p>1.<br />
The sticky emulation environment provided by ‘<code>emulate</code> <code>shell</code>
<code>-c</code>’ is identical to that provided by entry to a function marked
for sticky emulation as a consequence of being defined in such an
environment. Hence, for example, the sticky emulation is inherited
by subfunctions defined within functions with sticky emulation.</p>
</li>
<li>
<p>2.<br />
No change of options takes place on entry to or exit from functions
that are not marked for sticky emulation, other than those that
would normally take place, even if those functions are called within
sticky emulation.</p>
</li>
<li>
<p>3.<br />
No special handling is provided for functions marked for <code>autoload</code>
nor for functions present in wordcode created by the <code>zcompile</code>
command.</p>
</li>
<li>
<p>4.<br />
The presence or absence of the <code>-R</code> switch to <code>emulate</code> corresponds
to different sticky emulation modes, so for example ‘<code>emulate sh -c</code>’, ‘<code>emulate -R sh -c</code>’ and ‘<code>emulate csh -c</code>’ are treated as
three distinct sticky emulations.</p>
</li>
<li>
<p>5.<br />
Difference in shell options supplied in addition to the basic
emulation also mean the sticky emulations are different, so for
example ‘<code>emulate zsh -c</code>’ and ‘<code>emulate zsh -o cbases -c</code>’ are
treated as distinct sticky emulations.</p>
</li>
</ul>
<p><span id="index-enable"></span>
<span id="index-enabling-commands"></span>
<span id="index-commands_002c-enabling"></span></p>
<p><code>enable</code> [ <code>-afmprs</code> ] <code>name</code> ...</p>
<p>earlier with <code>disable</code>. The default is to enable builtin commands. The
<code>-a</code> option causes <code>enable</code> to act on regular or global aliases. The
<code>-s</code> option causes <code>enable</code> to act on suffix aliases. The <code>-f</code> option
causes <code>enable</code> to act on shell functions. The <code>-r</code> option causes
<code>enable</code> to act on reserved words. Without arguments printed. With the
<code>-m</code> flag the arguments are taken as patterns disabled with the
<code>disable</code> builtin command.</p>
<p><code>enable -p</code> reenables patterns disabled with <code>disable -p</code>. Note that it
does not override globbing options; for example, ‘<code>enable -p &quot;~&quot;</code>’ does
not cause the pattern character <code>~</code> to be active unless the
<code>EXTENDED_GLOB</code> option is also set. To enable all possible patterns (so
that they may be individually disabled with <code>disable -p</code>), use ‘<code>setopt EXTENDED_GLOB KSH_GLOB NO_SH_GLOB</code>’.</p>
<p><span id="index-eval"></span>
<span id="index-evaluating-arguments-as-commands"></span></p>
<p><code>eval</code> [ <code>arg</code> ... ]</p>
<p>Read the arguments as input to the shell and execute the resulting
command(s) in the current shell process. The return status is the same
as if the commands had been executed directly by the shell; if there are
no <code>args</code> or they contain no commands (i.e. are an empty string or
whitespace) the return status is zero.</p>
<p><code>exec</code> [ <code>-cl</code> ] [ <code>-a</code> <code>argv0</code> ] [ <code>command</code> [ <code>arg</code> ... ] ]</p>
<p>Replace the current shell with <code>command</code> rather than forking. If
<code>command</code> is a shell builtin command or a shell function, the shell
executes it, and exits when the command is complete.</p>
<p>With <code>-c</code> clear the environment; with <code>-l</code> prepend <code>-</code> to the <code>argv[0]</code>
string of the command executed (to simulate a login shell); with <code>-a</code>
<code>argv0</code> set the <code>argv[0]</code> string of the command executed. See
<a href="Shell-Grammar.html#Precommand-Modifiers">Precommand Modifiers</a>.</p>
<p>If the option <code>POSIX_BUILTINS</code> is set, <code>command</code> is never interpreted as
a shell builtin command or shell function. This means further precommand
modifiers such as <code>builtin</code> and <code>noglob</code> are also not interpreted within
the shell. Hence <code>command</code> is always found by searching the command
path.</p>
<p><span id="index-redirection_002c-current-shell_0027s-I_002fO"></span></p>
<p>If <code>command</code> is omitted but any redirections are specified, then the
redirections will take effect in the current shell.</p>
<p><span id="index-exit"></span></p>
<p><code>exit</code> [ <code>n</code> ]</p>
<p>Exit the shell with the exit status specified by an arithmetic
expression <code>n</code>; if none is specified, use the exit status from the last
command executed. <span id="index-IGNORE_005fEOF_002c-use-of"></span> An
EOF condition will also cause the shell to exit, unless the <code>IGNORE_EOF</code>
option is set.</p>
<p>See notes at the end of <a href="Jobs-_0026-Signals.html#Jobs-_0026-Signals">Jobs &amp;
Signals</a> for some possibly
unexpected interactions of the <code>exit</code> command with jobs.</p>
<p><span id="index-export-1"></span></p>
<p><code>export</code> [ <code>name</code>[<code>=``value</code>] ... ]</p>
<p>The specified <code>name</code>s are marked for automatic export to the environment
of subsequently executed commands. Equivalent to <code>typeset -gx</code>. If a
parameter specified does not already exist, it is created in the global
scope.</p>
<p><span id="index-false"></span>
<span id="index-doing-nothing_002c-unsuccessfully"></span></p>
<p><code>false</code> [ <code>arg</code> ... ]</p>
<p>Do nothing and return an exit status of 1.</p>
<p><span id="index-fc"></span>
<span id="index-history_002c-editing"></span>
<span id="index-editing-history"></span></p>
<p><code>fc</code> [ <code>-e</code> <code>ename</code> ] [ <code>-LI</code> ] [ <code>-m</code> <code>match</code> ] [ <code>old``=``new</code>
... ] [ <code>first</code> [ <code>last</code> ] ]</p>
<p><code>fc -l </code>[ <code>-LI</code> ] [ <code>-nrdfEiD</code> ] [ <code>-t</code> <code>timefmt</code> ] [ <code>-m</code>
<code>match</code> ]</p>
<p><code>      </code>[ <code>old``=``new</code> ... ] [ <code>first</code> [ <code>last</code> ] ]</p>
<p><code>fc -p </code>[ <code>-a</code> ] [ <code>filename</code> [ <code>histsize</code> [ <code>savehistsize</code> ] ]
]</p>
<p><code>fc</code> <code>-P</code></p>
<p><code>fc</code> <code>-ARWI</code> [ <code>filename</code> ]</p>
<p>The <code>fc</code> command controls the interactive history mechanism. Note that
reading and writing of history options is only performed if the shell is
interactive. Usually this is detected automatically, but it can be
forced by setting the <code>interactive</code> option when starting the shell.</p>
<p>The first two forms of this command select a range of events from
<code>first</code> to <code>last</code> from the history list. The arguments <code>first</code> and
<code>last</code> may be specified as a number or as a string. A negative number is
used as an offset to the current history event number. A string
specifies the most recent event beginning with the given string. All
substitutions <code>old``=``new</code>, if any, are then performed on the text of
the events.</p>
<p>In addition to the number range,</p>
<ul>
<li>
<p><code>-I</code><br />
restricts to only internal events (not from <code>$HISTFILE</code>)</p>
</li>
<li>
<p><code>-L</code><br />
restricts to only local events (not from other shells, see
<code>SHARE_HISTORY</code> in <a href="Options.html#Description-of-Options">Description of
Options</a> – note that
<code>$HISTFILE</code> is considered local when read at startup)</p>
</li>
<li>
<p><code>-m</code><br />
takes the first argument as a pattern (should be quoted) and only
the history events matching this pattern are considered</p>
</li>
</ul>
<p>If <code>first</code> is not specified, it will be set to -1 (the most recent
event), or to -16 if the <code>-l</code> flag is given. If <code>last</code> is not specified,
it will be set to <code>first</code>, or to -1 if the <code>-l</code> flag is given. However,
if the current event has added entries to the history with ‘<code>print -s</code>’
or ‘<code>fc -R</code>’, then the default <code>last</code> for <code>-l</code> includes all new history
entries since the current event began.</p>
<p>When the <code>-l</code> flag is given, the resulting events are listed on standard
output. Otherwise the editor program specified by <code>-e</code> <code>ename</code> is
invoked on a file containing these history events. If <code>-e</code> is not given,
the value of the parameter <code>FCEDIT</code> is used; if that is not set the
value of the parameter <code>EDITOR</code> is used; if that is not set a builtin
default, usually ‘<code>vi</code>’ is used. If <code>ename</code> is ‘<code>-</code>’, no editor is
invoked. When editing is complete, the edited command is executed.</p>
<p>The flag <code>-r</code> reverses the order of the events and the flag <code>-n</code>
suppresses event numbers when listing.</p>
<p>Also when listing,</p>
<ul>
<li>
<p><code>-d</code><br />
prints timestamps for each event</p>
</li>
<li>
<p><code>-f</code><br />
prints full time-date stamps in the US ‘<code>MM``/``DD``/``YY</code>
<code>hh``:``mm</code>’ format</p>
</li>
<li>
<p><code>-E</code><br />
prints full time-date stamps in the European ‘<code>dd``.``mm``.``yyyy</code>
<code>hh``:``mm</code>’ format</p>
</li>
<li>
<p><code>-i</code><br />
prints full time-date stamps in ISO8601 ‘<code>yyyy``-``mm``-``dd</code>
<code>hh``:``mm</code>’ format</p>
</li>
<li>
<p><code>-t</code> <code>fmt</code><br />
prints time and date stamps in the given format; <code>fmt</code> is formatted
with the strftime function with the zsh extensions described for the
<code>%D{``string``}</code> prompt format in <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>. The resulting
formatted string must be no more than 256 characters or will not be
printed</p>
</li>
<li>
<p><code>-D</code><br />
prints elapsed times; may be combined with one of the options above</p>
</li>
</ul>
<p><span id="index-history_002c-stack"></span>
<span id="index-stack_002c-history"></span></p>
<p>‘<code>fc -p</code>’ pushes the current history list onto a stack and switches to a
new history list. If the <code>-a</code> option is also specified, this history
list will be automatically popped when the current function scope is
exited, which is a much better solution than creating a trap function to
call ‘<code>fc -P</code>’ manually. If no arguments are specified, the history list
is left empty, <code>$HISTFILE</code> is unset, and <code>$HISTSIZE</code> &amp; <code>$SAVEHIST</code> are
set to their default values. If one argument is given, <code>$HISTFILE</code> is
set to that filename, <code>$HISTSIZE</code> &amp; <code>$SAVEHIST</code> are left unchanged, and
the history file is read in (if it exists) to initialize the new list.
If a second argument is specified, <code>$HISTSIZE</code> &amp; <code>$SAVEHIST</code> are instead
set to the single specified numeric value. Finally, if a third argument
is specified, <code>$SAVEHIST</code> is set to a separate value from <code>$HISTSIZE</code>.
You are free to change these environment values for the new history list
however you desire in order to manipulate the new history list.</p>
<p>‘<code>fc -P</code>’ pops the history list back to an older list saved by ‘<code>fc -p</code>’. The current list is saved to its <code>$HISTFILE</code> before it is
destroyed (assuming that <code>$HISTFILE</code> and <code>$SAVEHIST</code> are set
appropriately, of course). The values of <code>$HISTFILE</code>, <code>$HISTSIZE</code>, and
<code>$SAVEHIST</code> are restored to the values they had when ‘<code>fc -p</code>’ was
called. Note that this restoration can conflict with making these
variables &quot;local&quot;, so your best bet is to avoid local declarations for
these variables in functions that use ‘<code>fc -p</code>’. The one other
guaranteed-safe combination is declaring these variables to be local at
the top of your function and using the automatic option (<code>-a</code>) with ‘<code>fc -p</code>’. Finally, note that it is legal to manually pop a push marked for
automatic popping if you need to do so before the function exits.</p>
<p><span id="index-history_002c-file"></span>
<span id="index-file_002c-history"></span></p>
<p>‘<code>fc -R</code>’ reads the history from the given file, ‘<code>fc -W</code>’ writes the
history out to the given file, and ‘<code>fc -A</code>’ appends the history out to
the given file. If no filename is specified, the <code>$HISTFILE</code> is assumed.
If the <code>-I</code> option is added to <code>-R</code>, only those events that are not
already contained within the internal history list are added. If the
<code>-I</code> option is added to <code>-A</code> or <code>-W</code>, only those events that are new
since last incremental append/write to the history file are
appended/written. In any case, the created file will have no more than
<code>$SAVEHIST</code> entries.</p>
<p><span id="index-fg"></span>
<span id="index-jobs_002c-foregrounding"></span>
<span id="index-jobs_002c-resuming"></span></p>
<p><code>fg</code> [ <code>job</code> ... ]</p>
<p><code>job</code> ...</p>
<p>Bring each specified <code>job</code> in turn to the foreground. If no <code>job</code> is
specified, resume the current job.</p>
<p><span id="index-float"></span></p>
<p><code>float</code> [ {<code>+</code>|<code>-</code>}<code>Hghlprtux</code> ] [ {<code>+</code>|<code>-</code>}<code>EFLRZ</code> [ <code>n</code> ] ] [
<code>name</code>[<code>=``value</code>] ... ]</p>
<p>Equivalent to <code>typeset -E</code>, except that options irrelevant to floating
point numbers are not permitted.</p>
<p><span id="index-functions-1"></span></p>
<p><code>functions</code> [ {<code>+</code>|<code>-</code>}<code>UkmtTuWz</code> ] [ <code>-x</code> <code>num</code> ] [ <code>name</code> ... ]</p>
<p><code>functions -c</code> <code>oldfn</code> <code>newfn</code></p>
<p><code>functions -M</code> [<code>-s</code>] <code>mathfn</code> [ <code>min</code> [ <code>max</code> [ <code>shellfn</code> ] ] ]</p>
<p><code>functions -M</code> [ <code>-m</code> <code>pattern</code> ... ]</p>
<p><code>functions +M</code> [ <code>-m</code> ] <code>mathfn</code> ...</p>
<p>Equivalent to <code>typeset -f</code>, with the exception of the <code>-c</code>, <code>-x</code>, <code>-M</code>
and <code>-W</code> options. For <code>functions -u</code> and <code>functions -U</code>, see <code>autoload</code>,
which provides additional options.</p>
<p>The <code>-x</code> option indicates that any functions output will have each
leading tab for indentation, added by the shell to show syntactic
structure, expanded to the given number <code>num</code> of spaces. <code>num</code> can also
be 0 to suppress all indentation.</p>
<p>The <code>-W</code> option turns on the option <code>WARN_NESTED_VAR</code> for the named
function or functions only. The option is turned off at the start of
nested functions (apart from anonoymous functions) unless the called
function also has the <code>-W</code> attribute.</p>
<p>The <code>-c</code> option causes <code>oldfn</code> to be copied to <code>newfn</code>. The copy is
efficiently handled internally by reference counting. If <code>oldfn</code> was
marked for autoload it is first loaded and if this fails the copy fails.
Either function may subsequently be redefined without affecting the
other. A typical idiom is that <code>oldfn</code> is the name of a library shell
function which is then redefined to call <code>newfn</code>, thereby installing a
modified version of the function.</p>
<p>Use of the <code>-M</code> option may not be combined with any of the options
handled by <code>typeset -f</code>.</p>
<p><code>functions -M</code> <code>mathfn</code> defines <code>mathfn</code> as the name of a mathematical
function recognised in all forms of arithmetical expressions; see
<a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a>. By
default <code>mathfn</code> may take any number of comma-separated arguments. If
<code>min</code> is given, it must have exactly <code>min</code> args; if <code>min</code> and <code>max</code> are
both given, it must have at least <code>min</code> and at most <code>max</code> args. <code>max</code>
may be -1 to indicate that there is no upper limit.</p>
<p>By default the function is implemented by a shell function of the same
name; if <code>shellfn</code> is specified it gives the name of the corresponding
shell function while <code>mathfn</code> remains the name used in arithmetical
expressions. The name of the function in <code>$0</code> is <code>mathfn</code> (not <code>shellfn</code>
as would usually be the case), provided the option <code>FUNCTION_ARGZERO</code> is
in effect. The positional parameters in the shell function correspond to
the arguments of the mathematical function call. The result of the last
arithmetical expression evaluated inside the shell function (even if it
is a form that normally only returns a status) gives the result of the
mathematical function.</p>
<p>If the additional option <code>-s</code> is given to <code>functions -M</code>, the argument
to the function is a single string: anything between the opening and
matching closing parenthesis is passed to the function as a single
argument, even if it includes commas or white space. The minimum and
maximum argument specifiers must therefore be 1 if given. An empty
argument list is passed as a zero-length string.</p>
<p><code>functions -M</code> with no arguments lists all such user-defined functions
in the same form as a definition. With the additional option <code>-m</code> and a
list of arguments, all functions whose <code>mathfn</code> matches one of the
pattern arguments are listed.</p>
<p><code>function +M</code> removes the list of mathematical functions; with the
additional option <code>-m</code> the arguments are treated as patterns and all
functions whose <code>mathfn</code> matches the pattern are removed. Note that the
shell function implementing the behaviour is not removed (regardless of
whether its name coincides with <code>mathfn</code>).</p>
<p>For example, the following prints the cube of 3:</p>
<div class="example">
<pre><code class="language-example">zmath_cube() { (( $1 * $1 * $1 )) }
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))
</code></pre>
</div>
<p>The following string function takes a single argument, including the
commas, so prints 11:</p>
<div class="example">
<pre><code class="language-example">stringfn() { (( $#1 )) }
functions -Ms stringfn
print $(( stringfn(foo,bar,rod) ))
</code></pre>
</div>
<p><code>getcap</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fcap-Module">The zsh/cap Module</a>.</p>
<p><span id="index-getln"></span>
<span id="index-line_002c-reading"></span>
<span id="index-reading-a-line"></span></p>
<p><code>getln</code> [ <code>-AclneE</code> ] <code>name</code> ...</p>
<p>Read the top value from the buffer stack and put it in the shell
parameter <code>name</code>. Equivalent to <code>read -zr</code>.</p>
<p><span id="index-getopts"></span>
<span id="index-options_002c-processing"></span></p>
<p><code>getopts</code> <code>optstring</code> <code>name</code> [ <code>arg</code> ... ]</p>
<p>Checks the <code>arg</code>s for legal options. If the <code>arg</code>s are omitted, use the
positional parameters. A valid option argument begins with a ‘<code>+</code>’ or a
‘<code>-</code>’. An argument not beginning with a ‘<code>+</code>’ or a ‘<code>-</code>’, or the
argument ‘<code>-``-</code>’, ends the options. Note that a single ‘<code>-</code>’ is not
considered a valid option argument. <code>optstring</code> contains the letters
that <code>getopts</code> recognizes. If a letter is followed by a ‘<code>:</code>’, that
option requires an argument. The options can be separated from the
argument by blanks.</p>
<p>Each time it is invoked, <code>getopts</code> places the option letter it finds in
the shell parameter <code>name</code>, prepended with a ‘<code>+</code>’ when <code>arg</code> begins
with a ‘<code>+</code>’. The index of the next <code>arg</code> is stored in <code>OPTIND</code>. The
option argument, if any, is stored in <code>OPTARG</code>.
<span id="index-OPTIND_002c-use-of"></span>
<span id="index-OPTARG_002c-use-of"></span></p>
<p>The first option to be examined may be changed by explicitly assigning
to <code>OPTIND</code>. <code>OPTIND</code> has an initial value of <code>1</code>, and is normally set
to <code>1</code> upon entry to a shell function and restored upon exit (this is
disabled by the <code>POSIX_BUILTINS</code> option). <code>OPTARG</code> is not reset and
retains its value from the most recent call to <code>getopts</code>. If either of
<code>OPTIND</code> or <code>OPTARG</code> is explicitly unset, it remains unset, and the
index or option argument is not stored. The option itself is still
stored in <code>name</code> in this case.</p>
<p>A leading ‘<code>:</code>’ in <code>optstring</code> causes <code>getopts</code> to store the letter of
any invalid option in <code>OPTARG</code>, and to set <code>name</code> to ‘<code>?</code>’ for an
unknown option and to ‘<code>:</code>’ when a required argument is missing.
Otherwise, <code>getopts</code> sets <code>name</code> to ‘<code>?</code>’ and prints an error message
when an option is invalid. The exit status is nonzero when there are no
more options.</p>
<p><span id="index-hash-1"></span></p>
<p><code>hash</code> [ <code>-Ldfmrv</code> ] [ <code>name</code>[<code>=``value</code>] ] ...</p>
<p><code>hash</code> can be used to directly modify the contents of the command</p>
<p>A command <code>name</code> starting with a <code>/</code> is never hashed, whether by
explicit use of the <code>hash</code> command or otherwise. Such a command is
always found by direct look up in the file system.</p>
<p>Given no arguments, and neither the <code>-r</code> or <code>-f</code> options,</p>
<p>It will be subsequently rebuilt in the normal fashion. all the absolute
directories in the <code>PATH</code>, These two options cannot be used with any
arguments.</p>
<p>The <code>-m</code> option causes the arguments to be taken as patterns matching
those patterns are printed. This is the only way to display</p>
<p>For each <code>name</code> with a corresponding <code>value</code>, put ‘<code>name</code>’ in whenever
‘<code>name</code>’ is used as a command argument, the shell will try to execute
the file given by ‘<code>value</code>’. that ‘<code>value</code>’ may be referred to as
‘<code>~``name</code>’.</p>
<p>For each <code>name</code> with no checking what the appropriate <code>value</code> is in the
normal manner for</p>
<p>added by explicit specification. If has no effect if used with <code>-f</code>.</p>
<p>the form of a call to hash.</p>
<p><span id="index-history-1"></span></p>
<p><code>history</code></p>
<p>Same as <code>fc -l</code>.</p>
<p><span id="index-integer"></span></p>
<p><code>integer</code> [ {<code>+</code>|<code>-</code>}<code>Hghlprtux</code> ] [ {<code>+</code>|<code>-</code>}<code>LRZi</code> [ <code>n</code> ] ] [
<code>name</code>[<code>=``value</code>] ... ]</p>
<p>Equivalent to <code>typeset -i</code>, except that options irrelevant to integers
are not permitted.</p>
<p><span id="index-jobs-1"></span></p>
<p><code>jobs</code> [ <code>-dlprs</code> ] [ <code>job</code> ... ]</p>
<p><code>jobs -Z</code> <code>string</code></p>
<p>Lists information about each given job, or all jobs if <code>job</code> is omitted.
The <code>-l</code> flag lists process IDs, and the <code>-p</code> flag lists process groups.
If the <code>-r</code> flag is specified only running jobs will be listed and if
the <code>-s</code> flag is given only stopped jobs are shown. If the <code>-d</code> flag is
given, the directory from which the job was started (which may not be
the current directory of the job) will also be shown.</p>
<p>The <code>-Z</code> option replaces the shell’s argument and environment space with
the given string, truncated if necessary to fit. This will normally be
visible in <code>ps</code> (man page ps(1)) listings. This feature is typically
used by daemons, to indicate their state.</p>
<p><span id="index-kill"></span> <span id="index-killing-jobs"></span>
<span id="index-jobs_002c-killing"></span></p>
<p><code>kill</code> [ <code>-s</code> <code>signal_name</code> | <code>-n</code> <code>signal_number</code> | <code>-``sig</code> ] <code>job</code>
...</p>
<p><code>kill</code> <code>-l</code> [ <code>sig</code> ... ]</p>
<p>Sends either <code>SIGTERM</code> or the specified signal to the given jobs or
processes. Signals are given by number or by names, with or without the
‘<code>SIG</code>’ prefix. If the signal being sent is not ‘<code>KILL</code>’ or ‘<code>CONT</code>’,
then the job will be sent a ‘<code>CONT</code>’ signal if it is stopped. The
argument <code>job</code> can be the process ID of a job not in the job list. In
the second form, <code>kill -l</code>, if <code>sig</code> is not specified the signal names
are listed. Otherwise, for each <code>sig</code> that is a name, the corresponding
signal number is listed. For each <code>sig</code> that is a signal number or a
number representing the exit status of a process which was terminated or
stopped by a signal the name of the signal is printed.</p>
<p>On some systems, alternative signal names are allowed for a few signals.
Typical examples are <code>SIGCHLD</code> and <code>SIGCLD</code> or <code>SIGPOLL</code> and <code>SIGIO</code>,
assuming they correspond to the same signal number. <code>kill -l</code> will only
list the preferred form, however <code>kill -l</code> <code>alt</code> will show if the
alternative form corresponds to a signal number. For example, under
Linux <code>kill -l IO</code> and <code>kill -l POLL</code> both output 29, hence <code>kill -IO</code>
and <code>kill -POLL</code> have the same effect.</p>
<p>Many systems will allow process IDs to be negative to kill a process
group or zero to kill the current process group.</p>
<p><span id="index-let"></span></p>
<p><code>let</code> <code>arg</code> ...</p>
<p>Evaluate each <code>arg</code> as an arithmetic expression. See <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a> for a
description of arithmetic expressions. The exit status is 0 if the value
of the last expression is nonzero, 1 if it is zero, and 2 if an error
occurred.</p>
<p><span id="index-limit"></span> <span id="index-resource-limits"></span>
<span id="index-limits_002c-resource"></span></p>
<p><code>limit</code> [ <code>-hs</code> ] [ <code>resource</code> [ <code>limit</code> ] ] ...</p>
<p>Set or display resource limits. Unless the <code>-s</code> flag is given, the limit
applies only the children of the shell. If <code>-s</code> is given without other
arguments, the resource limits of the current shell is set to the
previously set resource limits of the children.</p>
<p>If <code>limit</code> is not specified, print the current limit placed on
<code>resource</code>, otherwise set the limit to the specified value. If the <code>-h</code>
flag is given, use hard limits instead of soft limits. If no <code>resource</code>
is given, print all limits.</p>
<p>When looping over multiple resources, the shell will abort immediately
if it detects a badly formed argument. However, if it fails to set a
limit for some other reason it will continue trying to set the remaining
limits.</p>
<p><code>resource</code> can be one of:</p>
<ul>
<li>
<p><code>addressspace</code><br />
Maximum amount of address space used.</p>
</li>
<li>
<p><code>aiomemorylocked</code><br />
Maximum amount of memory locked in RAM for AIO operations.</p>
</li>
<li>
<p><code>aiooperations</code><br />
Maximum number of AIO operations.</p>
</li>
<li>
<p><code>cachedthreads</code><br />
Maximum number of cached threads.</p>
</li>
<li>
<p><code>coredumpsize</code><br />
Maximum size of a core dump.</p>
</li>
<li>
<p><code>cputime</code><br />
Maximum CPU seconds per process.</p>
</li>
<li>
<p><code>datasize</code><br />
Maximum data size (including stack) for each process.</p>
</li>
<li>
<p><code>descriptors</code><br />
Maximum value for a file descriptor.</p>
</li>
<li>
<p><code>filesize</code><br />
Largest single file allowed.</p>
</li>
<li>
<p><code>kqueues</code><br />
Maximum number of kqueues allocated.</p>
</li>
<li>
<p><code>maxproc</code><br />
Maximum number of processes.</p>
</li>
<li>
<p><code>maxpthreads</code><br />
Maximum number of threads per process.</p>
</li>
<li>
<p><code>memorylocked</code><br />
Maximum amount of memory locked in RAM.</p>
</li>
<li>
<p><code>memoryuse</code><br />
Maximum resident set size.</p>
</li>
<li>
<p><code>msgqueue</code><br />
Maximum number of bytes in POSIX message queues.</p>
</li>
<li>
<p><code>posixlocks</code><br />
Maximum number of POSIX locks per user.</p>
</li>
<li>
<p><code>pseudoterminals</code><br />
Maximum number of pseudo-terminals.</p>
</li>
<li>
<p><code>resident</code><br />
Maximum resident set size.</p>
</li>
<li>
<p><code>sigpending</code><br />
Maximum number of pending signals.</p>
</li>
<li>
<p><code>sockbufsize</code><br />
Maximum size of all socket buffers.</p>
</li>
<li>
<p><code>stacksize</code><br />
Maximum stack size for each process.</p>
</li>
<li>
<p><code>swapsize</code><br />
Maximum amount of swap used.</p>
</li>
<li>
<p><code>vmemorysize</code><br />
Maximum amount of virtual memory.</p>
</li>
</ul>
<p>Which of these resource limits are available depends on the system.
<code>resource</code> can be abbreviated to any unambiguous prefix. It can also be
an integer, which corresponds to the integer defined for the resource by
the operating system.</p>
<p>If argument corresponds to a number which is out of the range of the
resources configured into the shell, the shell will try to read or write
the limit anyway, and will report an error if this fails. As the shell
does not store such resources internally, an attempt to set the limit
will fail unless the <code>-s</code> option is present.</p>
<p><code>limit</code> is a number, with an optional scaling factor, as follows:</p>
<ul>
<li>
<p><code>n``h</code><br />
hours</p>
</li>
<li>
<p><code>n``k</code><br />
kilobytes (default)</p>
</li>
<li>
<p><code>n``m</code><br />
megabytes or minutes</p>
</li>
<li>
<p><code>n``g</code><br />
gigabytes</p>
</li>
<li>
<p>[<code>mm``:</code>]<code>ss</code><br />
minutes and seconds</p>
</li>
</ul>
<p>The <code>limit</code> command is not made available by default when the shell
starts in a mode emulating another shell. It can be made available with
the command ‘<code>zmodload -F zsh/rlimits b:limit</code>’.</p>
<p><span id="index-local"></span></p>
<p><code>local</code> [ {<code>+</code>|<code>-</code>}<code>AHUahlprtux</code> ] [ {<code>+</code>|<code>-</code>}<code>EFLRZi</code> [ <code>n</code> ] ]
[ <code>name</code>[<code>=``value</code>] ... ]</p>
<p>Same as <code>typeset</code>, except that the options <code>-g</code>, and <code>-f</code> are not
permitted. In this case the <code>-x</code> option does not force the use of <code>-g</code>,
i.e. exported variables will be local to functions.</p>
<p><span id="index-log"></span> <span id="index-watch_002c-use-of"></span>
<span id="index-watching-users"></span>
<span id="index-users_002c-watching"></span></p>
<p><code>log</code></p>
<p>List all users currently logged in who are affected by the current
setting of the <code>watch</code> parameter.</p>
<p><span id="index-logout"></span></p>
<p><code>logout</code> [ <code>n</code> ]</p>
<p>Same as <code>exit</code>, except that it only works in a login shell.</p>
<p><code>noglob</code> <code>simple command</code></p>
<p>See <a href="Shell-Grammar.html#Precommand-Modifiers">Precommand Modifiers</a>.</p>
<p><span id="index-popd"></span></p>
<p><code>popd</code> [ <code>-q</code> ] [ {<code>+</code>|<code>-</code>}<code>n</code> ]</p>
<p>Remove an entry from the directory stack, and perform a <code>cd</code> to the new
top directory. With no argument, the current top entry is removed. An
argument of the form ‘<code>+``n</code>’ identifies a stack entry by counting from
the left of the list shown by the <code>dirs</code> command, starting with zero. An
argument of the form <code>-``n</code> counts from the right.
<span id="index-PUSHD_005fMINUS_002c-use-of-1"></span> If the
<code>PUSHD_MINUS</code> option is set, the meanings of ‘<code>+</code>’ and ‘<code>-</code>’ in this
context are swapped.</p>
<p>If the <code>-q</code> (quiet) option is specified, the hook function <code>chpwd</code> and
the functions in the array <code>$chpwd_functions</code> are not called, and the
new directory stack is not printed. This is useful for calls to <code>popd</code>
that do not change the environment seen by an interactive user.</p>
<p><span id="index-print"></span></p>
<p><code>print </code>[ <code>-abcDilmnNoOpPrsSz</code> ] [ <code>-u</code> <code>n</code> ] [ <code>-f</code> <code>format</code> ]
[ <code>-C</code> <code>cols</code> ]</p>
<p><code>      </code>[ <code>-v</code> <code>name</code> ] [ <code>-xX</code> <code>tabstop</code> ] [ <code>-R</code> [ <code>-en</code> ]] [
<code>arg</code> ... ]</p>
<p>With the ‘<code>-f</code>’ option the arguments are printed as described by
<code>printf</code>. With no flags or with the flag ‘<code>-</code>’, the arguments are
printed on the standard output as described by <code>echo</code>, with the
following differences: the escape sequence ‘<code>\M-``x</code>’ (or ‘<code>\M``x</code>’)
metafies the character <code>x</code> (sets the highest bit), ‘<code>\C-``x</code>’ (or
‘<code>\C``x</code>’) produces a control character (‘<code>\C-@</code>’ and ‘<code>\C-?</code>’ give
the characters NULL and delete), a character code in octal is
represented by ‘<code>\``NNN</code>’ (instead of ‘<code>\0``NNN</code>’), and ‘<code>\E</code>’ is a
synonym for ‘<code>\e</code>’. Finally, if not in an escape sequence, ‘<code>\</code>’ escapes
the following character and is not printed.</p>
<ul>
<li>
<p><code>-a</code><br />
Print arguments with the column incrementing first. Only useful with
the <code>-c</code> and <code>-C</code> options.</p>
</li>
<li>
<p><code>-b</code><br />
Recognize all the escape sequences defined for the <code>bindkey</code>
command, see <a href="Zsh-Line-Editor.html#Zle-Builtins">Zle Builtins</a>.</p>
</li>
<li>
<p><code>-c</code><br />
Print the arguments in columns. Unless <code>-a</code> is also given, arguments
are printed with the row incrementing first.</p>
</li>
<li>
<p><code>-C</code> <code>cols</code><br />
Print the arguments in <code>cols</code> columns. Unless <code>-a</code> is also given,
arguments are printed with the row incrementing first.</p>
</li>
<li>
<p><code>-D</code><br />
Treat the arguments as paths, replacing directory prefixes with <code>~</code>
expressions corresponding to directory names, as appropriate.</p>
</li>
<li>
<p><code>-i</code><br />
If given together with <code>-o</code> or <code>-O</code>, sorting is performed
case-independently.</p>
</li>
<li>
<p><code>-l</code><br />
Print the arguments separated by newlines instead of spaces. Note:
if the list of arguments is empty, <code>print -l</code> will still output one
empty line. To print a possibly-empty list of arguments one per
line, use <code>print -C1</code>, as in ‘<code>print -rC1 – &quot;$list[@]&quot;</code>’.</p>
</li>
<li>
<p><code>-m</code><br />
Take the first argument as a pattern (should be quoted), and remove
it from the argument list together with subsequent arguments that do
not match this pattern.</p>
</li>
<li>
<p><code>-n</code><br />
Do not add a newline to the output.</p>
</li>
<li>
<p><code>-N</code><br />
Print the arguments separated and terminated by nulls. Again, <code>print -rNC1 – &quot;$list[@]&quot;</code> is a canonical way to print an arbitrary list as
null-delimited records.</p>
</li>
<li>
<p><code>-o</code><br />
Print the arguments sorted in ascending order.</p>
</li>
<li>
<p><code>-O</code><br />
Print the arguments sorted in descending order.</p>
</li>
<li>
<p><code>-p</code><br />
Print the arguments to the input of the coprocess.</p>
</li>
<li>
<p><code>-P</code><br />
Perform prompt expansion (see <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>). In combination
with ‘<code>-f</code>’, prompt escape sequences are parsed only within
interpolated arguments, not within the format string.</p>
</li>
<li>
<p><code>-r</code><br />
Ignore the escape conventions of <code>echo</code>.</p>
</li>
<li>
<p><code>-R</code><br />
Emulate the BSD <code>echo</code> command, which does not process escape
sequences unless the <code>-e</code> flag is given. The <code>-n</code> flag suppresses
the trailing newline. Only the <code>-e</code> and <code>-n</code> flags are recognized
after <code>-R</code>; all other arguments and options are printed.</p>
</li>
<li>
<p><code>-s</code><br />
Place the results in the history list instead of on the standard
output. Each argument to the <code>print</code> command is treated as a single
word in the history, regardless of its content.</p>
</li>
<li>
<p><code>-S</code><br />
Place the results in the history list instead of on the standard
output. In this case only a single argument is allowed; it will be
split into words as if it were a full shell command line. The effect
is similar to reading the line from a history file with the
<code>HIST_LEX_WORDS</code> option active.</p>
</li>
<li>
<p><code>-u</code> <code>n</code><br />
Print the arguments to file descriptor <code>n</code>.</p>
</li>
<li>
<p><code>-v</code> <code>name</code><br />
Store the printed arguments as the value of the parameter <code>name</code>.</p>
</li>
<li>
<p><code>-x</code> <code>tab-stop</code><br />
Expand leading tabs on each line of output in the printed string
assuming a tab stop every <code>tab-stop</code> characters. This is appropriate
for formatting code that may be indented with tabs. Note that
leading tabs of any argument to print, not just the first, are
expanded, even if <code>print</code> is using spaces to separate arguments (the
column count is maintained across arguments but may be incorrect on
output owing to previous unexpanded tabs).</p>
<p>The start of the output of each print command is assumed to be
aligned with a tab stop. Widths of multibyte characters are handled
if the option <code>MULTIBYTE</code> is in effect. This option is ignored if
other formatting options are in effect, namely column alignment or
<code>printf</code> style, or if output is to a special location such as shell
history or the command line editor.</p>
</li>
<li>
<p><code>-X</code> <code>tab-stop</code><br />
This is similar to <code>-x</code>, except that all tabs in the printed string
are expanded. This is appropriate if tabs in the arguments are</p>
</li>
<li>
<p><code>-z</code><br />
Push the arguments onto the editing buffer stack, separated by
spaces.</p>
</li>
</ul>
<p>If any of ‘<code>-m</code>’, ‘<code>-o</code>’ or ‘<code>-O</code>’ are used in combination with ‘<code>-f</code>’
and there are no arguments (after the removal process in the case of
‘<code>-m</code>’) then nothing is printed.</p>
<p><span id="index-printf"></span></p>
<p><code>printf</code> [ <code>-v</code> <code>name</code> ] <code>format</code> [ <code>arg</code> ... ]</p>
<p>Print the arguments according to the format specification. Formatting
rules are the same as used in C. The same escape sequences as for <code>echo</code>
are recognised in the format. All C conversion specifications ending in
one of <code>csdiouxXeEfgGn</code> are handled. In addition to this, ‘<code>%b</code>’ can be
used instead of ‘<code>%s</code>’ to cause escape sequences in the argument to be
recognised and ‘<code>%q</code>’ can be used to quote the argument in such a way
that allows it to be reused as shell input. With the numeric format
specifiers, if the corresponding argument starts with a quote character,
the numeric value of the following character is used as the number to
print; otherwise the argument is evaluated as an arithmetic expression.
See <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a> for a
description of arithmetic expressions. With ‘<code>%n</code>’, the corresponding
argument is taken as an identifier which is created as an integer
parameter.</p>
<p>Normally, conversion specifications are applied to each argument in
order but they can explicitly specify the <code>n</code>th argument is to be used
by replacing ‘<code>%</code>’ by ‘<code>%``n``$</code>’ and ‘<code>*</code>’ by ‘<code>*``n``$</code>’. It is
recommended that you do not mix references of this explicit style with
the normal style and the handling of such mixed styles may be subject to
future change.</p>
<p>If arguments remain unused after formatting, the format string is reused
until all arguments have been consumed. With the <code>print</code> builtin, this
can be suppressed by using the <code>-r</code> option. If more arguments are
required by the format than have been specified, the behaviour is as if
zero or an empty string had been specified as the argument.</p>
<p>The <code>-v</code> option causes the output to be stored as the value of the
parameter <code>name</code>, instead of printed. If <code>name</code> is an array and the
format string is reused when consuming arguments then one array element
will be used for each use of the format string.</p>
<p><span id="index-pushd"></span>
<span id="index-PUSHD_005fTO_005fHOME_002c-use-of"></span>
<span id="index-PUSHD_005fMINUS_002c-use-of-2"></span>
<span id="index-CDABLE_005fVARS_002c-use-of"></span>
<span id="index-PUSHD_005fSILENT_002c-use-of"></span></p>
<p><code>pushd</code> [ <code>-qsLP</code> ] [ <code>arg</code> ]</p>
<p><code>pushd</code> [ <code>-qsLP</code> ] <code>old</code> <code>new</code></p>
<p><code>pushd</code> [ <code>-qsLP</code> ] {<code>+</code>|<code>-</code>}<code>n</code></p>
<p>Change the current directory, and push the old current directory onto
the directory stack. In the first form, change the current directory to
<code>arg</code>. If <code>arg</code> is not specified, change to the second directory on the
stack (that is, exchange the top two entries), or change to <code>$HOME</code> if
the <code>PUSHD_TO_HOME</code> option is set or if there is only one entry on the
stack. Otherwise, <code>arg</code> is interpreted as it would be by <code>cd</code>. The
meaning of <code>old</code> and <code>new</code> in the second form is also the same as for
<code>cd</code>.</p>
<p>The third form of <code>pushd</code> changes directory by rotating the directory
list. An argument of the form ‘<code>+``n</code>’ identifies a stack entry by
counting from the left of the list shown by the <code>dirs</code> command, starting
with zero. An argument of the form ‘<code>-``n</code>’ counts from the right. If
the <code>PUSHD_MINUS</code> option is set, the meanings of ‘<code>+</code>’ and ‘<code>-</code>’ in this
context are swapped.</p>
<p>If the <code>-q</code> (quiet) option is specified, the hook function <code>chpwd</code> and
the functions in the array <code>$chpwd_functions</code> are not called, and the
new directory stack is not printed. This is useful for calls to <code>pushd</code>
that do not change the environment seen by an interactive user.</p>
<p>If the option <code>-q</code> is not specified and the shell option <code>PUSHD_SILENT</code>
is not set, the directory stack will be printed after a <code>pushd</code> is
performed.</p>
<p>The options <code>-s</code>, <code>-L</code> and <code>-P</code> have the same meanings as for the <code>cd</code>
builtin.</p>
<p><span id="index-pushln"></span></p>
<p><code>pushln</code> [ <code>arg</code> ... ]</p>
<p>Equivalent to <code>print -nz</code>.</p>
<p><span id="index-pwd"></span>
<span id="index-CHASE_005fLINKS_002c-use-of"></span></p>
<p><code>pwd</code> [ <code>-rLP</code> ]</p>
<p>Print the absolute pathname of the current working directory. If the
<code>-r</code> or the <code>-P</code> flag is specified, or the <code>CHASE_LINKS</code> option is set
and the <code>-L</code> flag is not given, the printed path will not contain
symbolic links.</p>
<p><span id="index-r"></span></p>
<p><code>r</code></p>
<p>Same as <code>fc -e -</code>.</p>
<p><span id="index-read"></span> <span id="index-IFS_002c-use-of-2"></span></p>
<p><code>read </code>[ <code>-rszpqAclneE</code> ] [ <code>-t</code> [ <code>num</code> ] ] [ <code>-k</code> [ <code>num</code> ]
] [ <code>-d</code> <code>delim</code> ]</p>
<p><code>     </code>[ <code>-u</code> <code>n</code> ] [ <code>name</code>[<code>?``prompt</code>] ] [ <code>name</code> ... ]</p>
<p><span id="index-REPLY_002c-use-of-2"></span>
<span id="index-reply_002c-use-of-1"></span></p>
<p>Read one line and break it into fields using the characters in <code>$IFS</code> as
separators, except as noted below. The first field is assigned to the
first <code>name</code>, the second field to the second <code>name</code>, etc., with leftover
fields assigned to the last <code>name</code>. If <code>name</code> is omitted then <code>REPLY</code> is
used for scalars and <code>reply</code> for arrays.</p>
<ul>
<li>
<p><code>-r</code><br />
Raw mode: a ‘<code>\</code>’ at the end of a line does not signify line
continuation and backslashes in the line don’t quote the following
character and are not removed.</p>
</li>
<li>
<p><code>-s</code><br />
Don’t echo back characters if reading from the terminal.</p>
</li>
<li>
<p><code>-q</code><br />
Read only one character from the terminal and set <code>name</code> to ‘<code>y</code>’ if
this character was ‘<code>y</code>’ or ‘<code>Y</code>’ and to ‘<code>n</code>’ otherwise. With this
flag set the return status is zero only if the character was ‘<code>y</code>’
or ‘<code>Y</code>’. This option may be used with a timeout (see <code>-t</code>); if the
read times out, or encounters end of file, status 2 is returned.
Input is read from the terminal unless one of <code>-u</code> or <code>-p</code> is
present. This option may also be used within zle widgets.</p>
</li>
<li>
<p><code>-k</code> [ <code>num</code> ]<br />
Read only one (or <code>num</code>) characters. All are assigned to the first
<code>name</code>, without word splitting. This flag is ignored when <code>-q</code> is
present. Input is read from the terminal unless one of <code>-u</code> or <code>-p</code>
is present. This option may also be used within zle widgets.</p>
<p>Note that despite the mnemonic ‘key’ this option does read full
characters, which may consist of multiple bytes if the option
<code>MULTIBYTE</code> is set.</p>
</li>
<li>
<p><code>-z</code><br />
Read one entry from the editor buffer stack and assign it to the
first <code>name</code>, without word splitting. Text is pushed onto the stack
with ‘<code>print -z</code>’ or with <code>push-line</code> from the line editor (see <a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh
Line Editor</a>). This flag is
ignored when the <code>-k</code> or <code>-q</code> flags are present.</p>
</li>
<li>
<p><code>-e</code><br />
<code>-E</code><br />
The input read is printed (echoed) to the standard output. If the
<code>-e</code> flag is used, no input is assigned to the parameters.</p>
</li>
<li>
<p><code>-A</code><br />
The first <code>name</code> is taken as the name of an array and all words are
assigned to it.</p>
</li>
<li>
<p><code>-c</code><br />
<code>-l</code><br />
These flags are allowed only if called inside a function used for
completion (specified with the <code>-K</code> flag to <code>compctl</code>). If the <code>-c</code>
flag is given, the words of the current command are read. If the
<code>-l</code> flag is given, the whole line is assigned as a scalar. If both
flags are present, <code>-l</code> is used and <code>-c</code> is ignored.</p>
</li>
<li>
<p><code>-n</code><br />
Together with <code>-c</code>, the number of the word the cursor is on is read.
With <code>-l</code>, the index of the character the cursor is on is read. Note
that the command name is word number 1, not word 0, and that when
the cursor is at the end of the line, its character index is the
length of the line plus one.</p>
</li>
<li>
<p><code>-u</code> <code>n</code><br />
Input is read from file descriptor <code>n</code>.</p>
</li>
<li>
<p><code>-p</code><br />
Input is read from the coprocess.</p>
</li>
<li>
<p><code>-d</code> <code>delim</code><br />
Input is terminated by the first character of <code>delim</code> instead of by
newline.</p>
</li>
<li>
<p><code>-t</code> [ <code>num</code> ]<br />
Test if input is available before attempting to read. If <code>num</code> is
present, it must begin with a digit and will be evaluated to give a
number of seconds, which may be a floating point number; in this
case the read times out if input is not available within this time.
If <code>num</code> is not present, it is taken to be zero, so that <code>read</code>
returns immediately if no input is available. If no input is
available, return status 1 and do not set any variables.</p>
<p>This option is not available when reading from the editor buffer
with <code>-z</code>, when called from within completion with <code>-c</code> or <code>-l</code>,
with <code>-q</code> which clears the input queue before reading, or within zle
where other mechanisms should be used to test for input.</p>
<p>Note that read does not attempt to alter the input processing mode.
The default mode is canonical input, in which an entire line is read
at a time, so usually ‘<code>read -t</code>’ will not read anything until an
entire line has been typed. However, when reading from the terminal
with <code>-k</code> input is processed one key at a time; in this case, only
availability of the first character is tested, so that e.g. ‘<code>read -t -k 2</code>’ can still block on the second character. Use two instances
of ‘<code>read -t -k</code>’ if this is not what is wanted.</p>
</li>
</ul>
<p>If the first argument contains a ‘<code>?</code>’, the remainder of this word is
used as a <code>prompt</code> on standard error when the shell is interactive.</p>
<p>The value (exit status) of <code>read</code> is 1 when an end-of-file is
encountered, or when <code>-c</code> or <code>-l</code> is present and the command is not
called from a <code>compctl</code> function, or as described for <code>-q</code>. Otherwise
the value is 0.</p>
<p>The behavior of some combinations of the <code>-k</code>, <code>-p</code>, <code>-q</code>, <code>-u</code> and <code>-z</code>
flags is undefined. Presently <code>-q</code> cancels all the others, <code>-p</code> cancels
<code>-u</code>, <code>-k</code> cancels <code>-z</code>, and otherwise <code>-z</code> cancels both <code>-p</code> and <code>-u</code>.</p>
<p>The <code>-c</code> or <code>-l</code> flags cancel any and all of <code>-kpquz</code>.</p>
<p><span id="index-parameters_002c-marking-readonly"></span></p>
<p><code>readonly</code></p>
<p>Same as <code>typeset -r</code>. With the <code>POSIX_BUILTINS</code> option set, same as
<code>typeset -gr</code>.</p>
<p><span id="index-rehash"></span></p>
<p><code>rehash</code></p>
<p>Same as <code>hash -r</code>.</p>
<p><span id="index-return"></span>
<span id="index-functions_002c-returning-from"></span></p>
<p><code>return</code> [ <code>n</code> ]</p>
<p>Causes a shell function or ‘<code>.</code>’ script to return to the invoking script
with the return status specified by an arithmetic expression <code>n</code>. If <code>n</code>
is omitted, the return status is that of the last command executed.</p>
<p>If <code>return</code> was executed from a trap in a <code>TRAP``NAL</code> function, the
effect is different for zero and non-zero return status. With zero
status (or after an implicit return at the end of the trap), the shell
will return to whatever it was previously processing; with a non-zero
status, the shell will behave as interrupted except that the return
status of the trap is retained. Note that the numeric value of the
signal which caused the trap is passed as the first argument, so the
statement ‘<code>return $((128+$1))</code>’ will return the same status as if the
signal had not been trapped.</p>
<p><code>sched</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fsched-Module">The zsh/sched Module</a>.</p>
<p><span id="index-set"></span>
<span id="index-parameters_002c-listing"></span>
<span id="index-parameters_002c-positional"></span>
<span id="index-parameters_002c-setting-array"></span>
<span id="index-array-parameters_002c-setting"></span>
<span id="index-KSH_005fARRAYS_002c-use-of-1"></span></p>
<p><code>set </code>[ {<code>+</code>|<code>-</code>}<code>options</code> | {<code>+</code>|<code>-</code>}<code>o</code> [ <code>option_name</code> ] ] ...
[ {<code>+</code>|<code>-</code>}<code>A</code> [ <code>name</code> ] ]</p>
<p><code>    </code>[ <code>arg</code> ... ]</p>
<p>Set the options for the shell and/or set the positional parameters, or
declare and set an array. If the <code>-s</code> option is given, it causes the
specified arguments to be sorted before assigning them to the positional
parameters (or to the array <code>name</code> if <code>-A</code> is used). With <code>+s</code> sort
arguments in descending order. For the meaning of the other flags, see
<a href="Options.html#Options">Options</a>. Flags may be specified by name using
the <code>-o</code> option. If no option name is supplied with <code>-o</code>, the current
option states are printed: see the description of <code>setopt</code> below for
more information on the format. With <code>+o</code> they are printed in a form
that can be used as input to the shell.</p>
<p>If the <code>-A</code> flag is specified, <code>name</code> is set to an array containing the
given <code>arg</code>s; if no <code>name</code> is specified, all arrays are printed together
with their values.</p>
<p>If <code>+A</code> is used and <code>name</code> is an array, the given arguments will replace
the initial elements of that array; if no <code>name</code> is specified, all
arrays are printed without their values.</p>
<p>The behaviour of arguments after <code>-A</code> <code>name</code> or <code>+A</code> <code>name</code> depends on
whether the option <code>KSH_ARRAYS</code> is set. If it is not set, all arguments
following <code>name</code> are treated as values for the array, regardless of
their form. If the option is set, normal option processing continues at
that point; only regular arguments are treated as values for the array.
This means that</p>
<div class="example">
<pre><code class="language-example">set -A array -x -- foo
</code></pre>
</div>
<p>sets <code>array</code> to ‘<code>-x -``- foo</code>’ if <code>KSH_ARRAYS</code> is not set, but sets the
array to <code>foo</code> and turns on the option ‘<code>-x</code>’ if it is set.</p>
<p>If the <code>-A</code> flag is not present, but there are arguments beyond the
options, the positional parameters are set. If the option list (if any)
is terminated by ‘<code>-``-</code>’, and there are no further arguments, the
positional parameters will be unset.</p>
<p>If no arguments and no ‘<code>-``-</code>’ are given, then the names and values of
all parameters are printed on the standard output. If the only argument
is ‘<code>+</code>’, the names of all parameters are printed.</p>
<p>For historical reasons, ‘<code>set -</code>’ is treated as ‘<code>set +xv</code>’ and ‘<code>set -</code>
<code>args</code>’ as ‘<code>set +xv –</code> <code>args</code>’ when in any other emulation mode than
zsh’s native mode.</p>
<p><code>setcap</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fcap-Module">The zsh/cap Module</a>.</p>
<p><span id="index-setopt"></span>
<span id="index-options_002c-setting"></span></p>
<p><code>setopt</code> [ {<code>+</code>|<code>-</code>}<code>options</code> | {<code>+</code>|<code>-</code>}<code>o</code> <code>option_name</code> ] [ <code>-m</code>
] [ <code>name</code> ... ]</p>
<p>Set the options for the shell. All options specified either with flags
or by name are set.</p>
<p>If no arguments are supplied, the names of all options currently set are
printed. The form is chosen so as to minimize the differences from the
default options for the current emulation (the default emulation being
native <code>zsh</code>, shown as <code>&lt;Z&gt;</code> in <a href="Options.html#Description-of-Options">Description of
Options</a>). Options that are on by
default for the emulation are shown with the prefix <code>no</code> only if they
are off, while other options are shown without the prefix <code>no</code> and only
if they are on. In addition to options changed from the default state by
the user, any options activated automatically by the shell (for example,
<code>SHIN_STDIN</code> or <code>INTERACTIVE</code>) will be shown in the list. The format is
further modified by the option <code>KSH_OPTION_PRINT</code>, however the rationale
for choosing options with or without the <code>no</code> prefix remains the same in
this case.</p>
<p>If the <code>-m</code> flag is given the arguments are taken as patterns (which
should be quoted to protect them from filename expansion), and all
options with names matching these patterns are set.</p>
<p>Note that a bad option name does not cause execution of subsequent shell
code to be aborted; this is behaviour is different from that of ‘<code>set -o</code>’. This is because <code>set</code> is regarded as a special builtin by the
POSIX standard, but <code>setopt</code> is not.</p>
<p><span id="index-shift"></span>
<span id="index-parameters_002c-positional-1"></span></p>
<p><code>shift</code> [ <code>-p</code> ] [ <code>n</code> ] [ <code>name</code> ... ]</p>
<p>The positional parameters <code>${``n</code>+1<code>}</code> ... are renamed to <code>$1</code> ...,
where <code>n</code> is an arithmetic expression that defaults to 1. If any <code>name</code>s
are given then the arrays with these names are shifted instead of the
positional parameters.</p>
<p>If the option <code>-p</code> is given arguments are instead removed (popped) from
the end rather than the start of the array.</p>
<p><span id="index-source"></span></p>
<p><code>source</code> <code>file</code> [ <code>arg</code> ... ]</p>
<p>Same as ‘<code>.</code>’, except that the current directory is always searched and
is always searched first, before directories in <code>$path</code>.</p>
<p><code>stat</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fstat-Module">The zsh/stat Module</a>.</p>
<p><span id="index-suspend"></span>
<span id="index-shell_002c-suspending"></span>
<span id="index-suspending-the-shell"></span></p>
<p><code>suspend</code> [ <code>-f</code> ]</p>
<p>Suspend the execution of the shell (send it a <code>SIGTSTP</code>) until it
receives a <code>SIGCONT</code>. Unless the <code>-f</code> option is given, this will refuse
to suspend a login shell.</p>
<p><span id="index-test"></span></p>
<p><code>test</code> [ <code>arg</code> ... ]</p>
<p><code>[</code> [ <code>arg</code> ... ] <code>]</code></p>
<p>Like the system version of <code>test</code>. Added for compatibility; use
conditional expressions instead (see <a href="Conditional-Expressions.html#Conditional-Expressions">Conditional
Expressions</a>). The
main differences between the conditional expression syntax and the
<code>test</code> and <code>[</code> builtins are: these commands are not handled
syntactically, so for example an empty variable expansion may cause an
argument to be omitted; syntax errors cause status 2 to be returned
instead of a shell error; and arithmetic operators expect integer
arguments rather than arithmetic expressions.</p>
<p>The command attempts to implement POSIX and its extensions where these
are specified. Unfortunately there are intrinsic ambiguities in the
syntax; in particular there is no distinction between test operators and
strings that resemble them. The standard attempts to resolve these for
small numbers of arguments (up to four); for five or more arguments
compatibility cannot be relied on. Users are urged wherever possible to
use the ‘<code>[[</code>’ test syntax which does not have these ambiguities.</p>
<p><span id="index-times"></span>
<span id="index-shell_002c-timing"></span>
<span id="index-timing-the-shell"></span></p>
<p><code>times</code></p>
<p>Print the accumulated user and system times for the shell and for
processes run from the shell.</p>
<p><span id="index-trap"></span>
<span id="index-signals_002c-trapping-1"></span>
<span id="index-trapping-signals-1"></span></p>
<p><code>trap</code> [ <code>arg</code> ] [ <code>sig</code> ... ]</p>
<p><code>arg</code> is a series of commands (usually quoted to protect it from
immediate evaluation by the shell) to be read and executed when the
shell receives any of the signals specified by one or more <code>sig</code> args.
Each <code>sig</code> can be given as a number, or as the name of a signal either
with or without the string <code>SIG</code> in front (e.g. 1, HUP, and SIGHUP are
all the same signal).</p>
<p>If <code>arg</code> is ‘<code>-</code>’, then the specified signals are reset to their
defaults, or, if no <code>sig</code> args are present, all traps are reset.</p>
<p>If <code>arg</code> is an empty string, then the specified signals are ignored by
the shell (and by the commands it invokes).</p>
<p>If <code>arg</code> is omitted but one or more <code>sig</code> args are provided (i.e. the
first argument is a valid signal number or name), the effect is the same
as if <code>arg</code> had been specified as ‘<code>-</code>’.</p>
<p>The <code>trap</code> command with no arguments prints a list of commands
associated with each signal.</p>
<p>If <code>sig</code> is <code>ZERR</code> then <code>arg</code> will be executed after each command with a
nonzero exit status. <code>ERR</code> is an alias for <code>ZERR</code> on systems that have
no <code>SIGERR</code> signal (this is the usual case).</p>
<p>If <code>sig</code> is <code>DEBUG</code> then <code>arg</code> will be executed before each command if
the option <code>DEBUG_BEFORE_CMD</code> is set (as it is by default), else after
each command. Here, a ‘command’ is what is described as a ‘sublist’ in
the shell grammar, see <a href="Shell-Grammar.html#Simple-Commands-_0026-Pipelines">Simple Commands &amp;
Pipelines</a>. If
<code>DEBUG_BEFORE_CMD</code> is set various additional features are available.
First, it is possible to skip the next command by setting the option
<code>ERR_EXIT</code>; see the description of the <code>ERR_EXIT</code> option in <a href="Options.html#Description-of-Options">Description
of Options</a>. Also, the shell
parameter <code>ZSH_DEBUG_CMD</code> is set to the string corresponding to the
command to be executed following the trap. Note that this string is
reconstructed from the internal format and may not be formatted the same
way as the original text. The parameter is unset after the trap is
executed.</p>
<p>If <code>sig</code> is <code>0</code> or <code>EXIT</code> and the <code>trap</code> statement is executed inside
the body of a function, then the command <code>arg</code> is executed after the
function completes. The value of <code>$?</code> at the start of execution is the
exit status of the shell or the return status of the function exiting.
If <code>sig</code> is <code>0</code> or <code>EXIT</code> and the <code>trap</code> statement is not executed
inside the body of a function, then the command <code>arg</code> is executed when
the shell terminates; the trap runs before any <code>zshexit</code> hook functions.</p>
<p><code>ZERR</code>, <code>DEBUG</code>, and <code>EXIT</code> traps are not executed inside other traps.
<code>ZERR</code> and <code>DEBUG</code> traps are kept within subshells, while other traps
are reset.</p>
<p>Note that traps defined with the <code>trap</code> builtin are slightly different
from those defined as ‘<code>TRAP``NAL</code> () { ... }’, as the latter have their
own function environment (line numbers, local variables, etc.) while the
former use the environment of the command in which they were called. For
example,</p>
<div class="example">
<pre><code class="language-example">trap 'print $LINENO' DEBUG
</code></pre>
</div>
<p>will print the line number of a command executed after it has run, while</p>
<div class="example">
<pre><code class="language-example">TRAPDEBUG() { print $LINENO; }
</code></pre>
</div>
<p>will always print the number zero.</p>
<p>Alternative signal names are allowed as described under <code>kill</code> above.
Defining a trap under either name causes any trap under an alternative
name to be removed. However, it is recommended that for consistency
users stick exclusively to one name or another.</p>
<p><span id="index-true"></span>
<span id="index-doing-nothing_002c-successfully"></span></p>
<p><code>true</code> [ <code>arg</code> ... ]</p>
<p>Do nothing and return an exit status of 0.</p>
<p><span id="index-ttyctl"></span>
<span id="index-tty_002c-freezing"></span></p>
<p><code>ttyctl</code> [ <code>-fu</code> ]</p>
<p>The <code>-f</code> option freezes the tty (i.e. terminal or terminal emulator),
and <code>-u</code> unfreezes it. When the tty is frozen, no changes made to the
tty settings by external programs will be honored by the shell, except
for changes in the size of the screen; the shell will simply reset the
settings to their previous values as soon as each command exits or is
suspended. Thus, <code>stty</code> and similar programs have no effect when the tty
is frozen. Freezing the tty does not cause the current state to be
remembered: instead, it causes future changes to the state to be
blocked.</p>
<p>Without options it reports whether the terminal is frozen or not.</p>
<p>Note that, regardless of whether the tty is frozen or not, the shell
needs to change the settings when the line editor starts, so unfreezing
the tty does not guarantee settings made on the command line are
preserved. Strings of commands run between editing the command line will
see a consistent tty state. See also the shell variable <code>STTY</code> for a
means of initialising the tty before running external commands.</p>
<p><span id="index-type"></span></p>
<p><code>type</code> [ <code>-wfpamsS</code> ] <code>name</code> ...</p>
<p>Equivalent to <code>whence -v</code>.</p>
<p><span id="index-typeset"></span>
<span id="index-parameters_002c-setting"></span>
<span id="index-parameters_002c-declaring"></span></p>
<p><code>typeset </code>[ {<code>+</code>|<code>-</code>}<code>AHUaghlmrtux</code> ] [ {<code>+</code>|<code>-</code>}<code>EFLRZip</code> [ <code>n</code>
] ]</p>
<p><code>        </code>[ <code>+</code> ] [ <code>name</code>[<code>=``value</code>] ... ]</p>
<p><code> typeset ``-T</code> [ {<code>+</code>|<code>-</code>}<code>Uglrux</code> ] [ {<code>+</code>|<code>-</code>}<code>LRZp</code> [ <code>n</code> ] ]</p>
<p><code>        </code>[ <code>+</code> | <code>SCALAR</code>[<code>=``value</code>] <code>array</code>[<code>=(``value</code> ...<code>)</code>]
[ <code>sep</code> ] ]</p>
<p><code>typeset</code> <code>-f</code> [ {<code>+</code>|<code>-</code>}<code>TUkmtuz</code> ] [ <code>+</code> ] [ <code>name</code> ... ]</p>
<p>Set or display attributes and values for shell parameters.</p>
<p>Except as noted below for control flags that change the behavior, a
parameter is created for each <code>name</code> that does not already refer to one.
When inside a function, a new parameter is created for every <code>name</code>
(even those that already exist), and is unset again when the function
completes. See <a href="Parameters.html#Local-Parameters">Local Parameters</a>. The
same rules apply to special shell parameters, which retain their special
attributes when made local.</p>
<p>For each <code>name``=``value</code> assignment, the parameter <code>name</code> is set to
<code>value</code>.</p>
<p>If the shell option <code>TYPESET_SILENT</code> is not set, for each remaining
<code>name</code> that refers to a parameter that is already set, the name and
value of the parameter are printed in the form of an assignment. Nothing
is printed for newly-created parameters, or when any attribute flags
listed below are given along with the <code>name</code>. Using ‘<code>+</code>’ instead of
minus to introduce an attribute turns it off.</p>
<p>If no <code>name</code> is present, the names and values of all parameters are
printed. In this case the attribute flags restrict the display to only
those parameters that have the specified attributes, and using ‘<code>+</code>’
rather than ‘<code>-</code>’ to introduce the flag suppresses printing of the
values of parameters when there is no parameter name.</p>
<p>All forms of the command handle scalar assignment. Array assignment is
possible if any of the reserved words <code>declare</code>, <code>export</code>, <code>float</code>,
<code>integer</code>, <code>local</code>, <code>readonly</code> or <code>typeset</code> is matched when the line is
parsed (N.B. not when it is executed). In this case the arguments are
parsed as assignments, except that the ‘<code>+=</code>’ syntax and the
<code>GLOB_ASSIGN</code> option are not supported, and scalar values after <code>=</code> are
<em>not</em> split further into words, even if expanded (regardless of the
setting of the <code>KSH_TYPESET</code> option; this option is obsolete).</p>
<p>Examples of the differences between command and reserved word parsing:</p>
<div class="example">
<pre><code class="language-example"># Reserved word parsing
typeset svar=$(echo one word) avar=(several words)
</code></pre>
</div>
<p>The above creates a scalar parameter <code>svar</code> and an array parameter
<code>avar</code> as if the assignments had been</p>
<div class="example">
<pre><code class="language-example">svar=&quot;one word&quot;
avar=(several words)
</code></pre>
</div>
<p>On the other hand:</p>
<div class="example">
<pre><code class="language-example"># Normal builtin interface
builtin typeset svar=$(echo two words)
</code></pre>
</div>
<p>The <code>builtin</code> keyword causes the above to use the standard builtin
interface to <code>typeset</code> in which argument parsing is performed in the
same way as for other commands. This example creates a scalar <code>svar</code>
containing the value <code>two</code> and another scalar parameter <code>words</code> with no
value. An array value in this case would either cause an error or be
treated as an obscure set of glob qualifiers.</p>
<p>Arbitrary arguments are allowed if they take the form of assignments
after command line expansion; however, these only perform scalar
assignment:</p>
<div class="example">
<pre><code class="language-example">var='svar=val'
typeset $var
</code></pre>
</div>
<p>The above sets the scalar parameter <code>svar</code> to the value <code>val</code>.
Parentheses around the value within <code>var</code> would not cause array
assignment as they will be treated as ordinary characters when <code>$var</code> is
substituted. Any non-trivial expansion in the name part of the
assignment causes the argument to be treated in this fashion:</p>
<div class="example">
<pre><code class="language-example">typeset {var1,var2,var3}=name
</code></pre>
</div>
<p>The above syntax is valid, and has the expected effect of setting the
three parameters to the same value, but the command line is parsed as a
set of three normal command line arguments to <code>typeset</code> after expansion.
Hence it is not possible to assign to multiple arrays by this means.</p>
<p>Note that each interface to any of the commands my be disabled
separately. For example, ‘<code>disable -r typeset</code>’ disables the reserved
word interface to <code>typeset</code>, exposing the builtin interface, while
‘<code>disable typeset</code>’ disables the builtin. Note that disabling the
reserved word interface for <code>typeset</code> may cause problems with the output
of ‘<code>typeset -p</code>’, which assumes the reserved word interface is
available in order to restore array and associative array values.</p>
<p>Unlike parameter assignment statements, <code>typeset</code>’s exit status on an
assignment that involves a command substitution does not reflect the
exit status of the command substitution. Therefore, to test for an error
in a command substitution, separate the declaration of the parameter
from its initialization:</p>
<div class="example">
<pre><code class="language-example"># WRONG
typeset var1=$(exit 1) || echo &quot;Trouble with var1&quot;
# RIGHT
typeset var1 &amp;&amp; var1=$(exit 1) || echo &quot;Trouble with var1&quot;
</code></pre>
</div>
<p>To initialize a parameter <code>param</code> to a command output and mark it
readonly, use <code> typeset -r ``param</code> or <code> readonly ``param</code> after the
parameter assignment statement.</p>
<p>If no attribute flags are given, and either no <code>name</code> arguments are
present or the flag <code>+m</code> is used, then each parameter name printed is
preceded by a list of the attributes of that parameter (<code>array</code>,
<code>association</code>, <code>exported</code>, <code>float</code>, <code>integer</code>, <code>readonly</code>, or
<code>undefined</code> for autoloaded parameters not yet loaded). If <code>+m</code> is used
with attribute flags, and all those flags are introduced with <code>+</code>, the
matching parameter names are printed but their values are not.</p>
<p>The following control flags change the behavior of <code>typeset</code>:</p>
<ul>
<li>
<p><code>+</code><br />
If ‘<code>+</code>’ appears by itself in a separate word as the last option,
then the names of all parameters (functions with <code>-f</code>) are printed,
but the values (function bodies) are not. No <code>name</code> arguments may
appear, and it is an error for any other options to follow ‘<code>+</code>’.
The effect of ‘<code>+</code>’ is as if all attribute flags which precede it
were given with a ‘<code>+</code>’ prefix. For example, ‘<code>typeset -U +</code>’ is
equivalent to ‘<code>typeset +U</code>’ and displays the names of all arrays
having the uniqueness attribute, whereas ‘<code>typeset -f -U +</code>’
displays the names of all autoloadable functions. If <code>+</code> is the only
option, then type information (array, readonly, etc.) is also
printed for each parameter, in the same manner as ‘<code>typeset +m &quot;*&quot;</code>’.</p>
</li>
<li>
<p><code>-g</code><br />
The <code>-g</code> (global) means that any resulting parameter will not be
restricted to local scope. Note that this does not necessarily mean
that the parameter will be global, as the flag will apply to any
existing parameter (even if unset) from an enclosing function. This
flag does not affect the parameter after creation, hence it has no
effect when listing existing parameters, nor does the flag <code>+g</code> have
any effect except in combination with <code>-m</code> (see below).</p>
</li>
<li>
<p><code>-m</code><br />
If the <code>-m</code> flag is given the <code>name</code> arguments are taken as patterns
(use quoting to prevent these from being interpreted as file
patterns). With no attribute flags, all parameters (or functions
with the <code>-f</code> flag) with matching names are printed (the shell
option <code>TYPESET_SILENT</code> is not used in this case).</p>
<p>If the <code>+g</code> flag is combined with <code>-m</code>, a new local parameter is
created for every matching parameter that is not already local.
Otherwise <code>-m</code> applies all other flags or assignments to the
existing parameters.</p>
<p>Except when assignments are made with <code>name``=``value</code>, using <code>+m</code>
forces the matching parameters and their attributes to be printed,
even inside a function. Note that <code>-m</code> is ignored if no patterns are
given, so ‘<code>typeset -m</code>’ displays attributes but ‘<code>typeset -a +m</code>’
does not.</p>
</li>
<li>
<p><code>-p</code> [ <code>n</code> ]<br />
If the <code>-p</code> option is given, parameters and values are printed in
the form of a typeset command with an assignment, regardless of
other flags and options. Note that the <code>-H</code> flag on parameters is
respected; no value will be shown for these parameters.</p>
<p><code>-p</code> may be followed by an optional integer argument. Currently only
the value <code>1</code> is supported. In this case arrays and associative
arrays are printed with newlines between indented elements for
readability.</p>
</li>
<li>
<p><code>-T</code> [ <code>scalar</code>[<code>=``value</code>] <code>array</code>[<code>=(``value</code> ...<code>)</code>] [
<code>sep</code> ] ]<br />
This flag has a different meaning when used with <code>-f</code>; see below.
Otherwise the <code>-T</code> option requires zero, two, or three arguments to
be present. With no arguments, the list of parameters created in
this fashion is shown. With two or three arguments, the first two
are the name of a scalar and of an array parameter (in that order)
that will be tied together in the manner of <code>$PATH</code> and <code>$path</code>. The
optional third argument is a single-character separator which will
be used to join the elements of the array to form the scalar; if
absent, a colon is used, as with <code>$PATH</code>. Only the first character
of the separator is significant; any remaining characters are
ignored. Multibyte characters are not yet supported.</p>
<p>Only one of the scalar and array parameters may be assigned an
initial value (the restrictions on assignment forms described above
also apply).</p>
<p>Both the scalar and the array may be manipulated as normal. If one
is unset, the other will automatically be unset too. There is no way
of untying the variables without unsetting them, nor of converting
the type of one of them with another <code>typeset</code> command; <code>+T</code> does
not work, assigning an array to <code>scalar</code> is an error, and assigning
a scalar to <code>array</code> sets it to be a single-element array.</p>
<p>Note that both ‘<code>typeset -xT ...</code>’ and ‘<code>export -T ...</code>’ work, but
only the scalar will be marked for export. Setting the value using
the scalar version causes a split on all separators (which cannot be
quoted). It is possible to apply <code>-T</code> to two previously tied
variables but with a different separator character, in which case
the variables remain joined as before but the separator is changed.</p>
<p>When an existing scalar is tied to a new array, the value of the
scalar is preserved but no attribute other than export will be
preserved.</p>
</li>
</ul>
<p>Attribute flags that transform the final value (<code>-L</code>, <code>-R</code>, <code>-Z</code>, <code>-l</code>,
<code>-u</code>) are only applied to the expanded value at the point of a parameter
expansion expression using ‘<code>$</code>’. They are not applied when a parameter
is retrieved internally by the shell for any purpose.</p>
<p>The following attribute flags may be specified:</p>
<ul>
<li>
<p><code>-A</code><br />
The names refer to associative array parameters; see <a href="Parameters.html#Array-Parameters">Array
Parameters</a>.</p>
</li>
<li>
<p><code>-L</code> [ <code>n</code> ]<br />
Left justify and remove leading blanks from the value when the
parameter is expanded. If <code>n</code> is nonzero, it defines the width of
the field. If <code>n</code> is zero, the width is determined by the width of
the value of the first assignment. In the case of numeric
parameters, the length of the complete value assigned to the
parameter is used to determine the width, not the value that would
be output.</p>
<p>The width is the count of characters, which may be multibyte
characters if the <code>MULTIBYTE</code> option is in effect. Note that the
screen width of the character is not taken into account; if this is
required, use padding with parameter expansion flags
<code>${(ml``...``)``...``}</code> as described in ‘Parameter Expansion Flags’
in <a href="Expansion.html#Parameter-Expansion">Parameter Expansion</a>.</p>
<p>When the parameter is expanded, it is filled on the right with
blanks or truncated if necessary to fit the field. Note truncation
can lead to unexpected results with numeric parameters. Leading
zeros are removed if the <code>-Z</code> flag is also set.</p>
</li>
<li>
<p><code>-R</code> [ <code>n</code> ]<br />
Similar to <code>-L</code>, except that right justification is used; when the
parameter is expanded, the field is left filled with blanks or
truncated from the end. May not be combined with the <code>-Z</code> flag.</p>
</li>
<li>
<p><code>-U</code><br />
For arrays (but not for associative arrays), keep only the first
occurrence of each duplicated value. This may also be set for tied
parameters (see <code>-T</code>) or colon-separated special parameters like
<code>PATH</code> or <code>FIGNORE</code>, etc. Note the flag takes effect on assignment,
and the type of the variable being assigned to is determinative; for
variables with shared values it is therefore recommended to set the
flag for all interfaces, e.g. ‘<code>typeset -U PATH path</code>’.</p>
<p>This flag has a different meaning when used with <code>-f</code>; see below.</p>
</li>
<li>
<p><code>-Z</code> [ <code>n</code> ]<br />
Specially handled if set along with the <code>-L</code> flag. Otherwise,
similar to <code>-R</code>, except that leading zeros are used for padding
instead of blanks if the first non-blank character is a digit.
Numeric parameters are specially handled: they are always eligible
for padding with zeroes, and the zeroes are inserted at an
appropriate place in the output.</p>
</li>
<li>
<p><code>-a</code><br />
The names refer to array parameters. An array parameter may be
created this way, but it may be assigned to in the <code>typeset</code>
statement only if the reserved word form of <code>typeset</code> is enabled (as
it is by default). When displaying, both normal and associative
arrays are shown.</p>
</li>
<li>
<p><code>-f</code><br />
The names refer to functions rather than parameters. No assignments
can be made, and the only other valid flags are <code>-t</code>, <code>-T</code>, <code>-k</code>,
<code>-u</code>, <code>-U</code> and <code>-z</code>. The flag <code>-t</code> turns on execution tracing for
this function; the flag <code>-T</code> does the same, but turns off tracing
for any named (not anonymous) function called from the present one,
unless that function also has the <code>-t</code> or <code>-T</code> flag. The <code>-u</code> and
<code>-U</code> flags cause the function to be marked for autoloading; <code>-U</code>
also causes alias expansion to be suppressed when the function is
loaded. See the description of the ‘<code>autoload</code>’ builtin for details.</p>
<p>Note that the builtin <code>functions</code> provides the same basic
capabilities as <code>typeset -f</code> but gives access to a few extra
options; <code>autoload</code> gives further additional options for the case
<code>typeset -fu</code> and <code>typeset -fU</code>.</p>
</li>
<li>
<p><code>-h</code><br />
<code>-H</code><br />
Hide value: specifies that <code>typeset</code> will not display the value of
the parameter when listing parameters; the display for such
parameters is always as if the ‘<code>+</code>’ flag had been given. Use of the
parameter is in other respects normal, and the option does not apply
if the parameter is specified by name, or by pattern with the <code>-m</code>
option. This is on by default for the parameters in the
<code>zsh/parameter</code> and <code>zsh/mapfile</code> modules. Note, however, that
unlike the <code>-h</code> flag this is also useful for non-special parameters.</p>
</li>
<li>
<p><code>-i</code> [ <code>n</code> ]<br />
Use an internal integer representation. If <code>n</code> is nonzero it defines
the output arithmetic base, otherwise it is determined by the first
assignment. Bases from 2 to 36 inclusive are allowed.</p>
</li>
<li>
<p><code>-E</code> [ <code>n</code> ]<br />
Use an internal double-precision floating point representation. On
output the variable will be converted to scientific notation. If <code>n</code>
is nonzero it defines the number of significant figures to display;
the default is ten.</p>
</li>
<li>
<p><code>-F</code> [ <code>n</code> ]<br />
Use an internal double-precision floating point representation. On
output the variable will be converted to fixed-point decimal
notation. If <code>n</code> is nonzero it defines the number of digits to
display after the decimal point; the default is ten.</p>
</li>
<li>
<p><code>-l</code><br />
Convert the result to lower case whenever the parameter is expanded.
The value is <em>not</em> converted when assigned.</p>
</li>
<li>
<p><code>-r</code><br />
The given <code>name</code>s are marked readonly. Note that if <code>name</code> is a
special parameter, the readonly attribute can be turned on, but
cannot then be turned off.</p>
<p>If the <code>POSIX_BUILTINS</code> option is set, the readonly attribute is
more restrictive: unset variables can be marked readonly and cannot
then be set; furthermore, the readonly attribute cannot be removed
from any variable.</p>
<p>It is still possible to change other attributes of the variable
though, some of which like <code>-U</code> or <code>-Z</code> would affect the value. More
generally, the readonly attribute should not be relied on as a
security mechanism.</p>
<p>Note that in zsh (like in pdksh but unlike most other shells) it is
still possible to create a local variable of the same name as this
is considered a different variable (though this variable, too, can
be marked readonly). Special variables that have been made readonly
retain their value and readonly attribute when made local.</p>
</li>
<li>
<p><code>-t</code><br />
Tags the named parameters. Tags have no special meaning to the
shell. This flag has a different meaning when used with <code>-f</code>; see
above.</p>
</li>
<li>
<p><code>-u</code><br />
Convert the result to upper case whenever the parameter is expanded.
The value is <em>not</em> converted when assigned. This flag has a
different meaning when used with <code>-f</code>; see above.</p>
</li>
<li>
<p><code>-x</code><br />
Mark for automatic export to the environment of subsequently
executed commands. If the option <code>GLOBAL_EXPORT</code> is set, this
implies the option <code>-g</code>, unless <code>+g</code> is also explicitly given; in
other words the parameter is not made local to the enclosing
function. This is for compatibility with previous versions of zsh.</p>
</li>
</ul>
<p><span id="index-ulimit"></span>
<span id="index-resource-limits-1"></span>
<span id="index-limits_002c-resource-1"></span></p>
<p><code>ulimit</code> [ <code>-HSa</code> ] [ { <code>-bcdfiklmnpqrsTtvwx</code> | <code>-N</code> <code>resource</code> } [
<code>limit</code> ] ... ]</p>
<p>Set or display resource limits of the shell and the processes started by
the shell. The value of <code>limit</code> can be a number in the unit specified
below or one of the values ‘<code>unlimited</code>’, which removes the limit on the
resource, or ‘<code>hard</code>’, which uses the current value of the hard limit on
the resource.</p>
<p>By default, only soft limits are manipulated. If the <code>-H</code> flag is given
use hard limits instead of soft limits. If the <code>-S</code> flag is given
together with the <code>-H</code> flag set both hard and soft limits.</p>
<p>If no options are used, the file size limit (<code>-f</code>) is assumed.</p>
<p>If <code>limit</code> is omitted the current value of the specified resources are
printed. When more than one resource value is printed, the limit name
and unit is printed before each value.</p>
<p>When looping over multiple resources, the shell will abort immediately
if it detects a badly formed argument. However, if it fails to set a
limit for some other reason it will continue trying to set the remaining
limits.</p>
<p>Not all the following resources are supported on all systems. Running
<code>ulimit -a</code> will show which are supported.</p>
<ul>
<li>
<p><code>-a</code><br />
Lists all of the current resource limits.</p>
</li>
<li>
<p><code>-b</code><br />
Socket buffer size in bytes (N.B. not kilobytes)</p>
</li>
<li>
<p><code>-c</code><br />
512-byte blocks on the size of core dumps.</p>
</li>
<li>
<p><code>-d</code><br />
Kilobytes on the size of the data segment.</p>
</li>
<li>
<p><code>-f</code><br />
512-byte blocks on the size of files written.</p>
</li>
<li>
<p><code>-i</code><br />
The number of pending signals.</p>
</li>
<li>
<p><code>-k</code><br />
The number of kqueues allocated.</p>
</li>
<li>
<p><code>-l</code><br />
Kilobytes on the size of locked-in memory.</p>
</li>
<li>
<p><code>-m</code><br />
Kilobytes on the size of physical memory.</p>
</li>
<li>
<p><code>-n</code><br />
open file descriptors.</p>
</li>
<li>
<p><code>-p</code><br />
The number of pseudo-terminals.</p>
</li>
<li>
<p><code>-q</code><br />
Bytes in POSIX message queues.</p>
</li>
<li>
<p><code>-r</code><br />
Maximum real time priority. On some systems where this is not
available, such as NetBSD, this has the same effect as <code>-T</code> for
compatibility with <code>sh</code>.</p>
</li>
<li>
<p><code>-s</code><br />
Kilobytes on the size of the stack.</p>
</li>
<li>
<p><code>-T</code><br />
The number of simultaneous threads available to the user.</p>
</li>
<li>
<p><code>-t</code><br />
CPU seconds to be used.</p>
</li>
<li>
<p><code>-u</code><br />
The number of processes available to the user.</p>
</li>
<li>
<p><code>-v</code><br />
Kilobytes on the size of virtual memory. On some systems this refers
to the limit called ‘address space’.</p>
</li>
<li>
<p><code>-w</code><br />
Kilobytes on the size of swapped out memory.</p>
</li>
<li>
<p><code>-x</code><br />
The number of locks on files.</p>
</li>
</ul>
<p>A resource may also be specified by integer in the form ‘<code>-N</code>
<code>resource</code>’, where <code>resource</code> corresponds to the integer defined for
the resource by the operating system. This may be used to set the limits
for resources known to the shell which do not correspond to option
letters. Such limits will be shown by number in the output of ‘<code>ulimit -a</code>’.</p>
<p>The number may alternatively be out of the range of limits compiled into
the shell. The shell will try to read or write the limit anyway, and
will report an error if this fails.</p>
<p><span id="index-umask"></span> <span id="index-umask-1"></span></p>
<p><code>umask</code> [ <code>-S</code> ] [ <code>mask</code> ]</p>
<p>The umask is set to <code>mask</code>. <code>mask</code> can be either an octal number or a
symbolic value as described in man page chmod(1). If <code>mask</code> is omitted,
the current value is printed. The <code>-S</code> option causes the mask to be
printed as a symbolic value. Otherwise, the mask is printed as an octal
number. Note that in the symbolic form the permissions you specify are
those which are to be allowed (not denied) to the users specified.</p>
<p><span id="index-aliases_002c-removing"></span></p>
<p><code>unalias</code> [ <code>-ams</code> ] <code>name</code> ...</p>
<p>Removes aliases. This command works the same as <code>unhash -a</code>, except that
the <code>-a</code> option removes all regular or global aliases, or with <code>-s</code> all
suffix aliases: in this case no <code>name</code> arguments may appear. The options
<code>-m</code> (remove by pattern) and <code>-s</code> without <code>-a</code> (remove listed suffix
aliases) behave as for <code>unhash -a</code>. Note that the meaning of <code>-a</code> is
different between <code>unalias</code> and <code>unhash</code>.</p>
<p><span id="index-functions_002c-removing"></span>
<span id="index-unfunction"></span></p>
<p><code>unfunction</code></p>
<p>Same as <code>unhash -f</code>.</p>
<p><span id="index-unhash"></span></p>
<p><code>unhash</code> [ <code>-adfms</code> ] <code>name</code> ...</p>
<p>option causes <code>unhash</code> to remove regular or global aliases; note when
removing a global aliases that the argument must be quoted to prevent it
from being expanded before being passed to the command. The <code>-s</code> option
causes <code>unhash</code> to remove suffix aliases. The <code>-f</code> option causes
<code>unhash</code> to remove shell functions. The <code>-d</code> options causes <code>unhash</code> to
remove named directories. If the <code>-m</code> flag is given the arguments are
taken as patterns (should be quoted) and all elements</p>
<p><span id="index-unlimit"></span>
<span id="index-resource-limits-2"></span>
<span id="index-limits_002c-resource-2"></span></p>
<p><code>unlimit</code> [ <code>-hs</code> ] <code>resource</code> ...</p>
<p>The resource limit for each <code>resource</code> is set to the hard limit. If the
<code>-h</code> flag is given and the shell has appropriate privileges, the hard
resource limit for each <code>resource</code> is removed. The resources of the
shell process are only changed if the <code>-s</code> flag is given.</p>
<p>The <code>unlimit</code> command is not made available by default when the shell
starts in a mode emulating another shell. It can be made available with
the command ‘<code>zmodload -F zsh/rlimits b:unlimit</code>’.</p>
<p><span id="index-unset"></span>
<span id="index-parameters_002c-unsetting"></span></p>
<p><code>unset</code> [ <code>-fmv</code> ] <code>name</code> ...</p>
<p>Each named parameter is unset. Local parameters remain local even if
unset; they appear unset within scope, but the previous value will still
reappear when the scope ends.</p>
<p>Individual elements of associative array parameters may be unset by
using subscript syntax on <code>name</code>, which should be quoted (or the entire
command prefixed with <code>noglob</code>) to protect the subscript from filename
generation.</p>
<p>If the <code>-m</code> flag is specified the arguments are taken as patterns
(should be quoted) and all parameters with matching names are unset.
Note that this cannot be used when unsetting associative array elements,
as the subscript will be treated as part of the pattern.</p>
<p>The <code>-v</code> flag specifies that <code>name</code> refers to parameters. This is the
default behaviour.</p>
<p><code>unset -f</code> is equivalent to <code>unfunction</code>.</p>
<p><span id="index-unsetopt"></span>
<span id="index-options_002c-unsetting"></span></p>
<p><code>unsetopt</code> [ {<code>+</code>|<code>-</code>}<code>options</code> | {<code>+</code>|<code>-</code>}<code>o</code> <code>option_name</code> ] [
<code>name</code> ... ]</p>
<p>Unset the options for the shell. All options specified either with flags
or by name are unset. If no arguments are supplied, the names of all
options currently unset are printed. If the <code>-m</code> flag is given the
arguments are taken as patterns (which should be quoted to preserve them
from being interpreted as glob patterns), and all options with names
matching these patterns are unset.</p>
<p><code>vared</code></p>
<p>See <a href="Zsh-Line-Editor.html#Zle-Builtins">Zle Builtins</a>.</p>
<p><span id="index-wait"></span> <span id="index-waiting-for-jobs"></span>
<span id="index-jobs_002c-waiting-for"></span></p>
<p><code>wait</code> [ <code>job</code> ... ]</p>
<p>Wait for the specified jobs or processes. If <code>job</code> is not given then all
currently active child processes are waited for. Each <code>job</code> can be
either a job specification or the process ID The exit status from this
command is that of the job waited for. If <code>job</code> represents an unknown
job or process ID, a warning is printed (unless the <code>POSIX_BUILTINS</code>
option is set) and the exit status is 127.</p>
<p>It is possible to wait for recent processes (specified by process ID,
not by job) that were running in the background even if the process has
exited. Typically the process ID will be recorded by capturing the value
of the variable <code>$!</code> immediately after the process has been started.
There is a limit on the number of process IDs remembered by the shell;
this is given by the value of the system configuration parameter
<code>CHILD_MAX</code>. When this limit is reached, older process IDs are
discarded, least recently started processes first.</p>
<p>Note there is no protection against the process ID wrapping, i.e. if the
wait is not executed soon enough there is a chance the process waited
for is the wrong one. A conflict implies both process IDs have been
generated by the shell, as other processes are not recorded, and that
the user is potentially interested in both, so this problem is intrinsic
to process IDs.</p>
<p><span id="index-whence"></span></p>
<p><code>whence</code> [ <code>-vcwfpamsS</code> ] [ <code>-x</code> <code>num</code> ] <code>name</code> ...</p>
<p>For each <code>name</code>, indicate how it would be interpreted if used as a
command name.</p>
<p>If <code>name</code> is not an alias, built-in command, external command, shell
function, hashed command, or a reserved word, the exit status shall be
non-zero, and — if <code>-v</code>, <code>-c</code>, or <code>-w</code> was passed — a message will be
written to standard output. (This is different from other shells that
write that message to standard error.)</p>
<p><code>whence</code> is most useful when <code>name</code> is only the last path component of a
command, i.e. does not include a ‘<code>/</code>’; in particular, pattern matching
only succeeds if just the non-directory component of the command is
passed.</p>
<ul>
<li>
<p><code>-v</code><br />
Produce a more verbose report.</p>
</li>
<li>
<p><code>-c</code><br />
Print the results in a csh-like format. This takes precedence over
<code>-v</code>.</p>
</li>
<li>
<p><code>-w</code><br />
For each <code>name</code>, print ‘<code>name``:</code> <code>word</code>’ where <code>word</code> is one of
<code>alias</code>, <code>builtin</code>, <code>command</code>, <code>function</code>, <code>hashed</code>, <code>reserved</code> or
<code>none</code>, according as <code>name</code> corresponds to an alias, a built-in
command, an external command, a shell function, a command defined
with the <code>hash</code> builtin, a reserved word, or is not recognised. This
takes precedence over <code>-v</code> and <code>-c</code>.</p>
</li>
<li>
<p><code>-f</code><br />
Causes the contents of a shell function to be displayed, which would
otherwise not happen unless the <code>-c</code> flag were used.</p>
</li>
<li>
<p><code>-p</code><br />
Do a path search for <code>name</code> even if it is an alias, reserved word,
shell function or builtin.</p>
</li>
<li>
<p><code>-a</code><br />
Do a search for all occurrences of <code>name</code> throughout the command
path. Normally only the first occurrence is printed.</p>
</li>
<li>
<p><code>-m</code><br />
The arguments are taken as patterns (pattern characters should be
quoted), and the information is displayed for each command matching
one of these patterns.</p>
</li>
<li>
<p><code>-s</code><br />
If a pathname contains symlinks, print the symlink-free pathname as
well.</p>
</li>
<li>
<p><code>-S</code><br />
As <code>-s</code>, but if the pathname had to be resolved by following
multiple symlinks, the intermediate steps are printed, too. The
symlink resolved at each step might be anywhere in the path.</p>
</li>
<li>
<p><code>-x</code> <code>num</code><br />
Expand tabs when outputting shell functions using the <code>-c</code> option.
This has the same effect as the <code>-x</code> option to the <code>functions</code>
builtin.</p>
</li>
</ul>
<p><span id="index-where"></span></p>
<p><code>where</code> [ <code>-wpmsS</code> ] [ <code>-x</code> <code>num</code> ] <code>name</code> ...</p>
<p>Equivalent to <code>whence -ca</code>.</p>
<p><span id="index-which"></span></p>
<p><code>which</code> [ <code>-wpamsS</code> ] [ <code>-x</code> <code>num</code> ] <code>name</code> ...</p>
<p>Equivalent to <code>whence -c</code>.</p>
<p><span id="index-zcompile"></span>
<span id="index-_002ezwc-files_002c-creation"></span>
<span id="index-compilation"></span></p>
<p><code>zcompile</code> [ <code>-U</code> ] [ <code>-z</code> | <code>-k</code> ] [ <code>-R</code> | <code>-M</code> ] <code>file</code> [
<code>name</code> ... ]</p>
<p><code>zcompile</code> <code>-ca</code> [ <code>-m</code> ] [ <code>-R</code> | <code>-M</code> ] <code>file</code> [ <code>name</code> ... ]</p>
<p><code>zcompile -t</code> <code>file</code> [ <code>name</code> ... ]</p>
<p>This builtin command can be used to compile functions or scripts,
storing the compiled form in a file, and to examine files containing the
compiled form. This allows faster autoloading of functions and sourcing
of scripts by avoiding parsing of the text when the files are read.</p>
<p>The first form (without the <code>-c</code>, <code>-a</code> or <code>-t</code> options) creates a
compiled file. If only the <code>file</code> argument is given, the output file has
the name ‘<code>file``.zwc</code>’ and will be placed in the same directory as the
<code>file</code>. The shell will load the compiled file instead of the normal
function file when the function is autoloaded; see
<a href="Functions.html#Functions">Functions</a> for a description of how
autoloaded functions are searched. The extension <code>.zwc</code> stands for ‘zsh
word code’.</p>
<p><span id="index-fpath_002c-with-zcompile"></span></p>
<p>If there is at least one <code>name</code> argument, all the named files are
compiled into the output <code>file</code> given as the first argument. If <code>file</code>
does not end in <code>.zwc</code>, this extension is automatically appended. Files
containing multiple compiled functions are called ‘digest’ files, and
are intended to be used as elements of the <code>FPATH</code>/<code>fpath</code> special
array.</p>
<p>The second form, with the <code>-c</code> or <code>-a</code> options, writes the compiled
definitions for all the named functions into <code>file</code>. For <code>-c</code>, the names
must be functions currently defined in the shell, not those marked for
autoloading. Undefined functions that are marked for autoloading may be
written by using the <code>-a</code> option, in which case the <code>fpath</code> is searched
and the contents of the definition files for those functions, if found,
are compiled into <code>file</code>. If both <code>-c</code> and <code>-a</code> are given, names of both
defined functions and functions marked for autoloading may be given. In
either case, the functions in files written with the <code>-c</code> or <code>-a</code> option
will be autoloaded as if the <code>KSH_AUTOLOAD</code> option were unset.</p>
<p>The reason for handling loaded and not-yet-loaded functions with
different options is that some definition files for autoloading define
multiple functions, including the function with the same name as the
file, and, at the end, call that function. In such cases the output of
‘<code>zcompile -c</code>’ does not include the additional functions defined in
the file, and any other initialization code in the file is lost. Using
‘<code>zcompile -a</code>’ captures all this extra information.</p>
<p>If the <code>-m</code> option is combined with <code>-c</code> or <code>-a</code>, the <code>name</code>s are used
as patterns and all functions whose names match one of these patterns
will be written. If no <code>name</code> is given, the definitions of all functions
currently defined or marked as autoloaded will be written.</p>
<p>Note the second form cannot be used for compiling functions that include
redirections as part of the definition rather than within the body of
the function; for example</p>
<div class="example">
<pre><code class="language-example">fn1() { { ... } &gt;~/logfile }
</code></pre>
</div>
<p>can be compiled but</p>
<div class="example">
<pre><code class="language-example">fn1() { ... } &gt;~/logfile
</code></pre>
</div>
<p>cannot. It is possible to use the first form of <code>zcompile</code> to compile
autoloadable functions that include the full function definition instead
of just the body of the function.</p>
<p>The third form, with the <code>-t</code> option, examines an existing compiled
file. Without further arguments, the names of the original files
compiled into it are listed. The first line of output shows the version
of the shell which compiled the file and how the file will be used (i.e.
by reading it directly or by mapping it into memory). With arguments,
nothing is output and the return status is set to zero if definitions
for <em>all</em> <code>name</code>s were found in the compiled file, and non-zero if the
definition for at least one <code>name</code> was not found.</p>
<p>Other options:</p>
<ul>
<li>
<p><code>-U</code><br />
Aliases are not expanded when compiling the <code>name</code>d files.</p>
</li>
<li>
<p><code>-R</code><br />
When the compiled file is read, its contents are copied into the
shell’s memory, rather than memory-mapped (see <code>-M</code>). This happens
automatically on systems that do not support memory mapping.</p>
<p>When compiling scripts instead of autoloadable functions, it is
often desirable to use this option; otherwise the whole file,
including the code to define functions which have already been
defined, will remain mapped, consequently wasting memory.</p>
</li>
<li>
<p><code>-M</code><br />
The compiled file is mapped into the shell’s memory when read. This
is done in such a way that multiple instances of the shell running
on the same host will share this mapped file. If neither <code>-R</code> nor
<code>-M</code> is given, the <code>zcompile</code> builtin decides what to do based on
the size of the compiled file.</p>
</li>
<li>
<p><code>-k</code><br />
<code>-z</code><br />
These options are used when the compiled file contains functions
which are to be autoloaded. If <code>-z</code> is given, the function will be
autoloaded as if the <code>KSH_AUTOLOAD</code> option is <em>not</em> set, even if it
is set at the time the compiled file is read, while if the <code>-k</code> is
given, the function will be loaded as if <code>KSH_AUTOLOAD</code> <em>is</em> set.
These options also take precedence over any <code>-k</code> or <code>-z</code> options
specified to the <code>autoload</code> builtin. If neither of these options is
given, the function will be loaded as determined by the setting of
the <code>KSH_AUTOLOAD</code> option at the time the compiled file is read.</p>
<p>These options may also appear as many times as necessary between the
listed <code>name</code>s to specify the loading style of all following
functions, up to the next <code>-k</code> or <code>-z</code>.</p>
</li>
</ul>
<p>The created file always contains two versions of the compiled format,
one for big-endian machines and one for small-endian machines. The
upshot of this is that the compiled file is machine independent and if
it is read or mapped, only one half of the file is actually used (and
mapped).</p>
<p><code>zformat</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil Module</a>.</p>
<p><code>zftp</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fzftp-Module">The zsh/zftp Module</a>.</p>
<p><code>zle</code></p>
<p>See <a href="Zsh-Line-Editor.html#Zle-Builtins">Zle Builtins</a>.</p>
<p><span id="index-zmodload"></span>
<span id="index-modules_002c-loading"></span>
<span id="index-loading-modules"></span></p>
<p><code>zmodload</code> [ <code>-dL</code> ] [ <code>-s</code> ] [ ... ]</p>
<p><code>zmodload -F</code> [ <code>-alLme</code> <code>-P</code> <code>param</code> ] <code>module</code> [ [<code>+-</code>]<code>feature</code>
... ]</p>
<p><code>zmodload -e</code> [ <code>-A</code> ] [ ... ]</p>
<p><code>zmodload</code> [ <code>-a</code> [ <code>-bcpf</code> [ <code>-I</code> ] ] ] [ <code>-iL</code> ] ...</p>
<p><code>zmodload</code> <code>-u</code> [ <code>-abcdpf</code> [ <code>-I</code> ] ] [ <code>-iL</code> ] ...</p>
<p><code>zmodload</code> <code>-A</code> [ <code>-L</code> ] [ <code>modalias</code>[<code>=``module</code>] ... ]</p>
<p><code>zmodload</code> <code>-R</code> <code>modalias</code> ...</p>
<p>Performs operations relating to zsh’s loadable modules. Loading of
modules while the shell is running (‘dynamical loading’) is not
available on all operating systems, or on all installations on a
particular operating system, although the <code>zmodload</code> command itself is
always available and can be used to manipulate modules built into
versions of the</p>
<p>Without arguments the names of all currently loaded binary modules are
printed. The <code>-L</code> option causes this list to be in the form of a series
of <code>zmodload</code> commands. Forms with arguments are:</p>
<ul>
<li>
<p><code>zmodload</code> [ <code>-is</code> ] <code>name</code> ...<br />
<code>zmodload</code> <code>-u</code> [ <code>-i</code> ] <code>name</code> ...<br />
In the simplest case, <code>zmodload</code> loads a binary module. The module
must be in a file with a name consisting of the specified <code>name</code>
followed by a standard suffix, usually ‘<code>.so</code>’ (‘<code>.sl</code>’ on HPUX). If
the module to be loaded is already loaded the duplicate module is
ignored. If <code>zmodload</code> detects an inconsistency, such as an invalid
module name or circular dependency list, the current code block is
aborted. If it is available, the module is loaded if necessary,
while if it is not available, non-zero status is silently returned.
The option <code>-i</code> is accepted for compatibility but has no effect.</p>
<p>The <code>name</code>d module is searched for in the same way a command is,
using <code>$module_path</code> instead of <code>$path</code>. However, the path search is
performed even when the module name contains a ‘<code>/</code>’, which it
usually does. There is no way to prevent the path search.</p>
<p>If the module supports features (see below), <code>zmodload</code> tries to
enable all features when loading a module. If the module was
successfully loaded but not all features could be enabled,
<code>zmodload</code> returns status 2.</p>
<p>If the option <code>-s</code> is given, no error is printed if the module was
not available (though other errors indicating a problem with the
module are printed). The return status indicates if the module was
loaded. This is appropriate if the caller considers the module
optional.</p>
<p>With <code>-u</code>, <code>zmodload</code> unloads modules. The same <code>name</code> must be given
that was given when the module was loaded, but it is not necessary
for the module to exist in the file system. The <code>-i</code> option
suppresses the error if the module is already unloaded (or was never
loaded).</p>
<p>Each module has a boot and a cleanup function. The module will not
be loaded if its boot function fails. Similarly a module can only be
unloaded if its cleanup function runs successfully.</p>
</li>
<li>
<p><code>zmodload -F</code> [ <code>-almLe</code> <code>-P</code> <code>param</code> ] <code>module</code> [
[<code>+-</code>]<code>feature</code> ... ]<br />
<code>zmodload -F</code> allows more selective control over the features
provided by modules. With no options apart from <code>-F</code>, the module
named <code>module</code> is loaded, if it was not already loaded, and the list
of <code>feature</code>s is set to the required state. If no <code>feature</code>s are
specified, the module is loaded, if it was not already loaded, but
the state of features is unchanged. Each feature may be preceded by
a <code>+</code> to turn the feature on, or <code>-</code> to turn it off; the <code>+</code> is
assumed if neither character is present. Any feature not explicitly
mentioned is left in its current state; if the module was not
previously loaded this means any such features will remain disabled.
The return status is zero if all features were set, 1 if the module
failed to load, and 2 if some features could not be set (for
example, a parameter couldn’t be added because there was a different
parameter of the same name) but the module was loaded.</p>
<p>The standard features are builtins, conditions, parameters and math
functions; these are indicated by the prefix ‘<code>b:</code>’, ‘<code>c:</code>’ (‘<code>C:</code>’
for an infix condition), ‘<code>p:</code>’ and ‘<code>f:</code>’, respectively, followed
by the name that the corresponding feature would have in the shell.
For example, ‘<code>b:strftime</code>’ indicates a builtin named <code>strftime</code> and
<code>p:EPOCHSECONDS</code> indicates a parameter named <code>EPOCHSECONDS</code>. The
module may provide other (‘abstract’) features of its own as
indicated by its documentation; these have no prefix.</p>
<p>With <code>-l</code> or <code>-L</code>, features provided by the module are listed. With
<code>-l</code> alone, a list of features together with their states is shown,
one feature per line. With <code>-L</code> alone, a <code>zmodload -F</code> command that
would cause enabled features of the module to be turned on is shown.
With <code>-lL</code>, a <code>zmodload -F</code> command that would cause all the
features to be set to their current state is shown. If one of these
combinations is given with the option <code>-P</code> <code>param</code> then the
parameter <code>param</code> is set to an array of features, either features
together with their state or (if <code>-L</code> alone is given) enabled
features.</p>
<p>With the option <code>-L</code> the module name may be omitted; then a list of
all enabled features for all modules providing features is printed
in the form of <code>zmodload -F</code> commands. If <code>-l</code> is also given, the
state of both enabled and disabled features is output in that form.</p>
<p>A set of features may be provided together with <code>-l</code> or <code>-L</code> and a
module name; in that case only the state of those features is
considered. Each feature may be preceded by <code>+</code> or <code>-</code> but the
character has no effect. If no set of features is provided, all
features are considered.</p>
<p>With <code>-e</code>, the command first tests that the module is loaded; if it
is not, status 1 is returned. If the module is loaded, the list of
features given as an argument is examined. Any feature given with no
prefix is simply tested to see if the module provides it; any
feature given with a prefix <code>+</code> or <code>-</code> is tested to see if is
provided and in the given state. If the tests on all features in the
list succeed, status 0 is returned, else status 1.</p>
<p>With <code>-m</code>, each entry in the given list of features is taken as a
pattern to be matched against the list of features provided by the
module. An initial <code>+</code> or <code>-</code> must be given explicitly. This may not
be combined with the <code>-a</code> option as autoloads must be specified
explicitly.</p>
<p>With <code>-a</code>, the given list of features is marked for autoload from
the specified module, which may not yet be loaded. An optional <code>+</code>
may appear before the feature name. If the feature is prefixed with
<code>-</code>, any existing autoload is removed. The options <code>-l</code> and <code>-L</code> may
be used to list autoloads. Autoloading is specific to individual
features; when the module is loaded only the requested feature is
enabled. Autoload requests are preserved if the module is
subsequently unloaded until an explicit ‘<code>zmodload -Fa</code> <code>module</code>
<code>-``feature</code>’ is issued. It is not an error to request an autoload
for a feature of a module that is already loaded.</p>
<p>When the module is loaded each autoload is checked against the
features actually provided by the module; if the feature is not
provided the autoload request is deleted. A warning message is
output; if the module is being loaded to provide a different
feature, and that autoload is successful, there is no effect on the
status of the current command. If the module is already loaded at
the time when <code>zmodload -Fa</code> is run, an error message is printed and
status 1 returned.</p>
<p><code>zmodload -Fa</code> can be used with the <code>-l</code>, <code>-L</code>, <code>-e</code> and <code>-P</code>
options for listing and testing the existence of autoloadable
features. In this case <code>-l</code> is ignored if <code>-L</code> is specified.
<code>zmodload -FaL</code> with no module name lists autoloads for all modules.</p>
<p>Note that only standard features as described above can be
autoloaded; other features require the module to be loaded before
enabling.</p>
</li>
<li>
<p><code>zmodload</code> <code>-d</code> [ <code>-L</code> ] [ <code>name</code> ]<br />
<code>zmodload</code> <code>-d</code> <code>name</code> <code>dep</code> ...<br />
<code>zmodload</code> <code>-ud</code> <code>name</code> [ <code>dep</code> ... ]<br />
The <code>-d</code> option can be used to specify module dependencies. The
modules named in the second and subsequent arguments will be loaded
before the module named in the first argument.</p>
<p>With <code>-d</code> and one argument, all dependencies for that module are
listed. With <code>-d</code> and no arguments, all module dependencies are
listed. This listing is by default in a Makefile-like format. The
<code>-L</code> option changes this format to a list of <code>zmodload -d</code> commands.</p>
<p>If <code>-d</code> and <code>-u</code> are both used, dependencies are removed. If only
one argument is given, all dependencies for that module are removed.</p>
</li>
<li>
<p><code>zmodload</code> <code>-ab</code> [ <code>-L</code> ]<br />
<code>zmodload</code> <code>-ab</code> [ <code>-i</code> ] <code>name</code> [ <code>builtin</code> ... ]<br />
<code>zmodload</code> <code>-ub</code> [ <code>-i</code> ] <code>builtin</code> ...<br />
The <code>-ab</code> option defines autoloaded builtins. It defines the
specified <code>builtin</code>s. When any of those builtins is called, the
module specified in the first argument is loaded and all its
features are enabled (for selective control of features use
‘<code>zmodload -F -a</code>’ as described above). If only the <code>name</code> is
given, one builtin is defined, with the same name as the module.
<code>-i</code> suppresses the error if the builtin is already defined or
autoloaded, but not if another builtin of the same name is already
defined.</p>
<p>With <code>-ab</code> and no arguments, all autoloaded builtins are listed,
with the module name (if different) shown in parentheses after the
builtin name. The <code>-L</code> option changes this format to a list of
<code>zmodload -a</code> commands.</p>
<p>If <code>-b</code> is used together with the <code>-u</code> option, it removes builtins
previously defined with <code>-ab</code>. This is only possible if the builtin
is not yet loaded. <code>-i</code> suppresses the error if the builtin is
already removed (or never existed).</p>
<p>Autoload requests are retained if the module is subsequently
unloaded until an explicit ‘<code>zmodload -ub</code> <code>builtin</code>’ is issued.</p>
</li>
<li>
<p><code>zmodload</code> <code>-ac</code> [ <code>-IL</code> ]<br />
<code>zmodload</code> <code>-ac</code> [ <code>-iI</code> ] <code>name</code> [ <code>cond</code> ... ]<br />
<code>zmodload</code> <code>-uc</code> [ <code>-iI</code> ] <code>cond</code> ...<br />
The <code>-ac</code> option is used to define autoloaded condition codes. The
<code>cond</code> strings give the names of the conditions defined by the
module. The optional <code>-I</code> option is used to define infix condition
names. Without this option prefix condition names are defined.</p>
<p>If given no condition names, all defined names are listed (as a
series of <code>zmodload</code> commands if the <code>-L</code> option is given).</p>
<p>The <code>-uc</code> option removes definitions for autoloaded conditions.</p>
</li>
<li>
<p><code>zmodload</code> <code>-ap</code> [ <code>-L</code> ]<br />
<code>zmodload</code> <code>-ap</code> [ <code>-i</code> ] <code>name</code> [ <code>parameter</code> ... ]<br />
<code>zmodload</code> <code>-up</code> [ <code>-i</code> ] <code>parameter</code> ...<br />
The <code>-p</code> option is like the <code>-b</code> and <code>-c</code> options, but makes
<code>zmodload</code> work on autoloaded parameters instead.</p>
</li>
<li>
<p><code>zmodload</code> <code>-af</code> [ <code>-L</code> ]<br />
<code>zmodload</code> <code>-af</code> [ <code>-i</code> ] <code>name</code> [ <code>function</code> ... ]<br />
<code>zmodload</code> <code>-uf</code> [ <code>-i</code> ] <code>function</code> ...<br />
The <code>-f</code> option is like the <code>-b</code>, <code>-p</code>, and <code>-c</code> options, but makes
<code>zmodload</code> work on autoloaded math functions instead.</p>
</li>
<li>
<p><code>zmodload</code> <code>-a</code> [ <code>-L</code> ]<br />
<code>zmodload</code> <code>-a</code> [ <code>-i</code> ] <code>name</code> [ <code>builtin</code> ... ]<br />
<code>zmodload</code> <code>-ua</code> [ <code>-i</code> ] <code>builtin</code> ...<br />
Equivalent to <code>-ab</code> and <code>-ub</code>.</p>
</li>
<li>
<p><code>zmodload -e</code> [ <code>-A</code> ] [ <code>string</code> ... ]<br />
The <code>-e</code> option without arguments lists all loaded modules; if the
<code>-A</code> option is also given, module aliases corresponding to loaded
modules are also shown. If arguments are provided, nothing is
printed; the return status is set to zero if all <code>string</code>s given as
arguments are names of loaded modules and to one if at least on
<code>string</code> is not the name of a loaded module. This can be used to
test for the availability of things implemented by modules. In this
case, any aliases are automatically resolved and the <code>-A</code> flag is
not used.</p>
</li>
<li>
<p><code>zmodload</code> <code>-A</code> [ <code>-L</code> ] [ <code>modalias</code>[<code>=``module</code>] ... ]<br />
For each argument, if both <code>modalias</code> and <code>module</code> are given, define
<code>modalias</code> to be an alias for the module <code>module</code>. If the module
<code>modalias</code> is ever subsequently requested, either via a call to
<code>zmodload</code> or implicitly, the shell will attempt to load <code>module</code>
instead. If <code>module</code> is not given, show the definition of
<code>modalias</code>. If no arguments are given, list all defined module
aliases. When listing, if the <code>-L</code> flag was also given, list the
definition as a <code>zmodload</code> command to recreate the alias.</p>
<p>The existence of aliases for modules is completely independent of
whether the name resolved is actually loaded as a module: while the
alias exists, loading and unloading the module under any alias has
exactly the same effect as using the resolved name, and does not
affect the connection between the alias and the resolved name which
can be removed either by <code>zmodload -R</code> or by redefining the alias.
Chains of aliases (i.e. where the first resolved name is itself an
alias) are valid so long as these are not circular. As the aliases
take the same format as module names, they may include path
separators: in this case, there is no requirement for any part of
the path named to exist as the alias will be resolved first. For
example, ‘<code>any/old/alias</code>’ is always a valid alias.</p>
<p>Dependencies added to aliased modules are actually added to the
resolved module; these remain if the alias is removed. It is valid
to create an alias whose name is one of the standard shell modules
and which resolves to a different module. However, if a module has
dependencies, it will not be possible to use the module name as an
alias as the module will already be marked as a loadable module in
its own right.</p>
<p>Apart from the above, aliases can be used in the <code>zmodload</code> command
anywhere module names are required. However, aliases will not be
shown in lists of loaded modules with a bare ‘<code>zmodload</code>’.</p>
</li>
<li>
<p><code>zmodload</code> <code>-R</code> <code>modalias</code> ...<br />
For each <code>modalias</code> argument that was previously defined as a module
alias via <code>zmodload -A</code>, delete the alias. If any was not defined,
an error is caused and the remainder of the line is ignored.</p>
</li>
</ul>
<p>Note that <code>zsh</code> makes no distinction between modules that were linked
into the shell and modules that are loaded dynamically. In both cases
this builtin command has to be used to make available the builtins and
other things defined by modules (unless the module is autoloaded on
these definitions). This is true even for systems that don’t support
dynamic loading of modules.</p>
<p><code>zparseopts</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil Module</a>.</p>
<p><code>zprof</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fzprof-Module">The zsh/zprof Module</a>.</p>
<p><code>zpty</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fzpty-Module">The zsh/zpty Module</a>.</p>
<p><code>zregexparse</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil Module</a>.</p>
<p><code>zsocket</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fnet_002fsocket-Module">The zsh/net/socket
Module</a>.</p>
<p><code>zstyle</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil Module</a>.</p>
<p><code>ztcp</code></p>
<p>See <a href="Zsh-Modules.html#The-zsh_002fnet_002ftcp-Module">The zsh/net/tcp
Module</a>.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Zsh-Line-Editor.html#18-zsh-line-editor">18 Zsh Line Editor</a>
<ul>
<li><a href="Zsh-Line-Editor.html#181-description">18.1 Description</a></li>
<li><a href="Zsh-Line-Editor.html#182-keymaps">18.2 Keymaps</a>
<ul>
<li><a href="Zsh-Line-Editor.html#1821-reading-commands">18.2.1 Reading Commands</a></li>
<li><a href="Zsh-Line-Editor.html#1822-local-keymaps">18.2.2 Local Keymaps</a></li>
</ul>
</li>
<li><a href="Zsh-Line-Editor.html#183-zle-builtins">18.3 Zle Builtins</a></li>
<li><a href="Zsh-Line-Editor.html#184-widgets">18.4 Widgets</a></li>
<li><a href="Zsh-Line-Editor.html#185-user-defined-widgets">18.5 User-Defined Widgets</a>
<ul>
<li><a href="Zsh-Line-Editor.html#1851-special-widgets">18.5.1 Special Widgets</a></li>
</ul>
</li>
<li><a href="Zsh-Line-Editor.html#186-standard-widgets">18.6 Standard Widgets</a>
<ul>
<li><a href="Zsh-Line-Editor.html#1861-movement">18.6.1 Movement</a></li>
<li><a href="Zsh-Line-Editor.html#1862-history-control">18.6.2 History Control</a></li>
<li><a href="Zsh-Line-Editor.html#1863-modifying-text">18.6.3 Modifying Text</a></li>
<li><a href="Zsh-Line-Editor.html#1864-arguments">18.6.4 Arguments</a></li>
<li><a href="Zsh-Line-Editor.html#1865-completion">18.6.5 Completion</a></li>
<li><a href="Zsh-Line-Editor.html#1866-miscellaneous">18.6.6 Miscellaneous</a></li>
<li><a href="Zsh-Line-Editor.html#1867-text-objects">18.6.7 Text Objects</a></li>
</ul>
</li>
<li><a href="Zsh-Line-Editor.html#187-character-highlighting">18.7 Character Highlighting</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Zsh-Line-Editor"></span> <span id="Zsh-Line-Editor-1"></span></p>
<h1 id="18-zsh-line-editor"><a class="header" href="#18-zsh-line-editor">18 Zsh Line Editor</a></h1>
<p><span id="index-line-editor"></span>
<span id="index-editor_002c-line"></span> <span id="index-ZLE-1"></span></p>
<hr />
<p><span id="Description-9"></span></p>
<h2 id="181-description"><a class="header" href="#181-description">18.1 Description</a></h2>
<p><span id="index-ZLE_002c-use-of"></span></p>
<p>If the <code>ZLE</code> option is set (which it is by default in interactive
shells) and the shell input is attached to the terminal, the user is
able to edit command lines.</p>
<p>There are two display modes. The first, multiline mode, is the default.
It only works if the <code>TERM</code> parameter is set to a valid terminal type
that can move the cursor up. The second, single line mode, is used if
<code>TERM</code> is invalid or incapable of moving the cursor up, or if the
<code>SINGLE_LINE_ZLE</code> option is set.
<span id="index-SINGLE_005fLINE_005fZLE_002c-use-of"></span>
<span id="index-ksh_002c-editor-mode"></span>
<span id="index-editor-ksh-style"></span> This mode is similar to ksh,
and uses no termcap sequences. If <code>TERM</code> is &quot;emacs&quot;, the <code>ZLE</code> option
will be unset by default.</p>
<p><span id="index-BAUD_002c-use-of"></span>
<span id="index-COLUMNS_002c-use-of"></span>
<span id="index-LINES_002c-use-of"></span></p>
<p>The parameters <code>BAUD</code>, <code>COLUMNS</code>, and <code>LINES</code> are also used by the line
editor. See <a href="Parameters.html#Parameters-Used-By-The-Shell">Parameters Used By The
Shell</a>.</p>
<p><span id="index-zle_005fhighlight_002c-use-of"></span></p>
<p>The parameter <code>zle_highlight</code> is also used by the line editor; see
<a href="Zsh-Line-Editor.html#Character-Highlighting">Character Highlighting</a>. Highlighting of
special characters and the region between the cursor and the mark (as
set with <code>set-mark-command</code> in Emacs mode, or by <code>visual-mode</code> in Vi
mode) is enabled by default; consult this reference for more
information. Irascible conservatives will wish to know that all
highlighting may be disabled by the following setting:</p>
<div class="example">
<pre><code class="language-example">zle_highlight=(none)
</code></pre>
</div>
<p>In many places, references are made to the <code>numeric argument</code>. This can
by default be entered in emacs mode by holding the alt key and typing a
number, or pressing escape before each digit, and in vi command mode by
typing the number before entering a command. Generally the numeric
argument causes the next command entered to be repeated the specified
number of times, unless otherwise noted below; this is implemented by
the <code>digit-argument</code> widget. See also <a href="Zsh-Line-Editor.html#Arguments">Arguments</a> for some
other ways the numeric argument can be modified.</p>
<hr />
<p><span id="Keymaps"></span> <span id="Keymaps-1"></span></p>
<h2 id="182-keymaps"><a class="header" href="#182-keymaps">18.2 Keymaps</a></h2>
<p><span id="index-keymaps"></span> <span id="index-key-bindings"></span>
<span id="index-bindings_002c-key"></span></p>
<p>A keymap in ZLE contains a set of bindings between key sequences and ZLE
commands. The empty key sequence cannot be bound.</p>
<p>There can be any number of keymaps at any time, and each keymap has one
or more names. If all of a keymap’s names are deleted, it disappears.
<span id="index-bindkey_002c-use-of"></span> <code>bindkey</code> can be used to
manipulate keymap names.</p>
<p>Initially, there are eight keymaps:</p>
<ul>
<li>
<p><code>emacs</code><br />
EMACS emulation</p>
</li>
<li>
<p><code>viins</code><br />
vi emulation - insert mode</p>
</li>
<li>
<p><code>vicmd</code><br />
vi emulation - command mode</p>
</li>
<li>
<p><code>viopp</code><br />
vi emulation - operator pending</p>
</li>
<li>
<p><code>visual</code><br />
vi emulation - selection active</p>
</li>
<li>
<p><code>isearch</code><br />
incremental search mode</p>
</li>
<li>
<p><code>command</code><br />
read a command name</p>
</li>
<li>
<p><code>.safe</code><br />
fallback keymap</p>
</li>
</ul>
<p>The ‘<code>.safe</code>’ keymap is special. It can never be altered, and the name
can never be removed. However, it can be linked to other names, which
can be removed. In the future other special keymaps may be added; users
should avoid using names beginning with ‘<code>.</code>’ for their own keymaps.</p>
<p><span id="index-VISUAL"></span> <span id="index-EDITOR"></span></p>
<p>In addition to these names, either ‘<code>emacs</code>’ or ‘<code>viins</code>’ is also linked
to the name ‘<code>main</code>’. If one of the <code>VISUAL</code> or <code>EDITOR</code> environment
variables contain the string ‘<code>vi</code>’ when the shell starts up then it
will be ‘<code>viins</code>’, otherwise it will be ‘<code>emacs</code>’. <code>bindkey</code>’s <code>-e</code> and
<code>-v</code> options provide a convenient way to override this default choice.</p>
<p>When the editor starts up, it will select the ‘<code>main</code>’ keymap. If that
keymap doesn’t exist, it will use ‘<code>.safe</code>’ instead.</p>
<p>In the ‘<code>.safe</code>’ keymap, each single key is bound to <code>self-insert</code>,
except for ^J (line feed) and ^M (return) which are bound to
<code>accept-line</code>. This is deliberately not pleasant to use; if you are
using it, it means you deleted the main keymap, and you should put it
back.</p>
<hr />
<p><span id="Reading-Commands"></span></p>
<h3 id="1821-reading-commands"><a class="header" href="#1821-reading-commands">18.2.1 Reading Commands</a></h3>
<p>When ZLE is reading a command from the terminal, it may read a sequence
that is bound to some command and is also a prefix of a longer bound
string. In this case ZLE will wait a certain time to see if more
characters are typed, and if not (or they don’t match any longer string)
it will execute the binding. This timeout is defined by the <code>KEYTIMEOUT</code>
parameter; its default is 0.4 sec. There is no timeout if the prefix
string is not itself bound to a command.</p>
<p>The key timeout is also applied when ZLE is reading the bytes from a
multibyte character string when it is in the appropriate mode. (This
requires that the shell was compiled with multibyte mode enabled;
typically also the locale has characters with the UTF-8 encoding,
although any multibyte encoding known to the operating system is
supported.) If the second or a subsequent byte is not read within the
timeout period, the shell acts as if <code>?</code> were typed and resets the input
state.</p>
<p>As well as ZLE commands, key sequences can be bound to other strings, by
using ‘<code>bindkey -s</code>’. When such a sequence is read, the replacement
string is pushed back as input, and the command reading process starts
again using these fake keystrokes. This input can itself invoke further
replacement strings, but in order to detect loops the process will be
stopped if there are twenty such replacements without a real command
being read.</p>
<p>A key sequence typed by the user can be turned into a command name for
use in user-defined widgets with the <code>read-command</code> widget, described in
<a href="Zsh-Line-Editor.html#Miscellaneous">Miscellaneous</a> below.</p>
<hr />
<p><span id="Local-Keymaps"></span></p>
<h3 id="1822-local-keymaps"><a class="header" href="#1822-local-keymaps">18.2.2 Local Keymaps</a></h3>
<p><span id="index-local-keymaps"></span></p>
<p>While for normal editing a single keymap is used exclusively, in many
modes a local keymap allows for some keys to be customised. For example,
in an incremental search mode, a binding in the <code>isearch</code> keymap will
override a binding in the <code>main</code> keymap but all keys that are not
overridden can still be used.</p>
<p>If a key sequence is defined in a local keymap, it will hide a key
sequence in the global keymap that is a prefix of that sequence. An
example of this occurs with the binding of <code>iw</code> in <code>viopp</code> as this hides
the binding of <code>i</code> in <code>vicmd</code>. However, a longer sequence in the global
keymap that shares the same prefix can still apply so for example the
binding of <code>^Xa</code> in the global keymap will be unaffected by the binding
of <code>^Xb</code> in the local keymap.</p>
<hr />
<p><span id="Zle-Builtins"></span> <span id="Zle-Builtins-1"></span></p>
<h2 id="183-zle-builtins"><a class="header" href="#183-zle-builtins">18.3 Zle Builtins</a></h2>
<p><span id="index-zle_002c-builtin-commands"></span></p>
<p>The ZLE module contains three related builtin commands. The <code>bindkey</code>
command manipulates keymaps and key bindings; the <code>vared</code> command
invokes ZLE on the value of a shell parameter; and the <code>zle</code> command
manipulates editing widgets and allows command line access to ZLE
commands from within shell functions.</p>
<p><span id="index-bindkey"></span>
<span id="index-keys_002c-rebinding"></span>
<span id="index-rebinding-keys"></span>
<span id="index-keys_002c-binding"></span>
<span id="index-binding-keys"></span> <span id="index-keymaps-1"></span></p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-l</code> [ <code>-L</code> ] [ <code>keymap</code> ... ]</p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-d</code></p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-D</code> <code>keymap</code> ...</p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-A</code> <code>old-keymap new-keymap</code></p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-N</code> <code>new-keymap</code> [ <code>old-keymap</code> ]</p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-m</code></p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-r</code> <code>in-string</code> ...</p>
<p><code>bindkey</code> [ <code>options</code> ] <code>-s</code> <code>in-string out-string</code> ...</p>
<p><code>bindkey</code> [ <code>options</code> ] <code>in-string command</code> ...</p>
<p><code>bindkey</code> [ <code>options</code> ] [ <code>in-string</code> ]</p>
<p><code>bindkey</code>’s options can be divided into three categories: keymap
selection for the current command, operation selection, and others. The
keymap selection options are:</p>
<ul>
<li>
<p><code>-e</code><br />
Selects keymap ‘<code>emacs</code>’ for any operations by the current command,
and also links ‘<code>emacs</code>’ to ‘<code>main</code>’ so that it is selected by
default the next time the editor starts.</p>
</li>
<li>
<p><code>-v</code><br />
Selects keymap ‘<code>viins</code>’ for any operations by the current command,
and also links ‘<code>viins</code>’ to ‘<code>main</code>’ so that it is selected by
default the next time the editor starts.</p>
</li>
<li>
<p><code>-a</code><br />
Selects keymap ‘<code>vicmd</code>’ for any operations by the current command.</p>
</li>
<li>
<p><code>-M</code> <code>keymap</code><br />
The <code>keymap</code> specifies a keymap name that is selected for any
operations by the current command.</p>
</li>
</ul>
<p>If a keymap selection is required and none of the options above are
used, the ‘<code>main</code>’ keymap is used. Some operations do not permit a
keymap to be selected, namely:</p>
<ul>
<li>
<p><code>-l</code><br />
List all existing keymap names; if any arguments are given, list
just those keymaps.</p>
<p>If the <code>-L</code> option is also used, list in the form of <code>bindkey</code>
commands to create or link the keymaps. ‘<code>bindkey -lL main</code>’ shows
which keymap is linked to ‘<code>main</code>’, if any, and hence if the
standard emacs or vi emulation is in effect. This option does not
show the <code>.safe</code> keymap because it cannot be created in that
fashion; however, neither is ‘<code>bindkey -lL .safe</code>’ reported as an
error, it simply outputs nothing.</p>
</li>
<li>
<p><code>-d</code><br />
Delete all existing keymaps and reset to the default state.</p>
</li>
<li>
<p><code>-D</code> <code>keymap</code> ...<br />
Delete the named <code>keymap</code>s.</p>
</li>
<li>
<p><code>-A</code> <code>old-keymap new-keymap</code><br />
Make the <code>new-keymap</code> name an alias for <code>old-keymap</code>, so that both
names refer to the same keymap. The names have equal standing; if
either is deleted, the other remains. If there is already a keymap
with the <code>new-keymap</code> name, it is deleted.</p>
</li>
<li>
<p><code>-N</code> <code>new-keymap</code> [ <code>old-keymap</code> ]<br />
Create a new keymap, named <code>new-keymap</code>. If a keymap already has
that name, it is deleted. If an <code>old-keymap</code> name is given, the new
keymap is initialized to be a duplicate of it, otherwise the new
keymap will be empty.</p>
</li>
</ul>
<p>To use a newly created keymap, it should be linked to <code>main</code>. Hence the
sequence of commands to create and use a new keymap ‘<code>mymap</code>’
initialized from the <code>emacs</code> keymap (which remains unchanged) is:</p>
<div class="example">
<pre><code class="language-example">bindkey -N mymap emacs
bindkey -A mymap main
</code></pre>
</div>
<p>Note that while ‘<code>bindkey -A</code> <code>newmap</code> <code>main</code>’ will work when <code>newmap</code>
is <code>emacs</code> or <code>viins</code>, it will not work for <code>vicmd</code>, as switching from
vi insert to command mode becomes impossible.</p>
<p>The following operations act on the ‘<code>main</code>’ keymap if no keymap
selection option was given:</p>
<ul>
<li>
<p><code>-m</code><br />
Add the built-in set of meta-key bindings to the selected keymap.
Only keys that are unbound or bound to <code>self-insert</code> are affected.</p>
</li>
<li>
<p><code>-r</code> <code>in-string</code> ...<br />
Unbind the specified <code>in-string</code>s in the selected keymap. This is
exactly equivalent to binding the strings to <code>undefined-key</code>.</p>
<p>When <code>-R</code> is also used, interpret the <code>in-string</code>s as ranges.</p>
<p>When <code>-p</code> is also used, the <code>in-string</code>s specify prefixes. Any
binding that has the given <code>in-string</code> as a prefix, not including
the binding for the <code>in-string</code> itself, if any, will be removed. For
example,</p>
<div class="example">
<pre><code class="language-example">bindkey -rpM viins '^['
</code></pre>
</div>
<p>will remove all bindings in the vi-insert keymap beginning with an
escape character (probably cursor keys), but leave the binding for
the escape character itself (probably <code>vi-cmd-mode</code>). This is
incompatible with the option <code>-R</code>.</p>
</li>
<li>
<p><code>-s</code> <code>in-string out-string</code> ...<br />
Bind each <code>in-string</code> to each <code>out-string</code>. When <code>in-string</code> is
typed, <code>out-string</code> will be pushed back and treated as input to the
line editor. When <code>-R</code> is also used, interpret the <code>in-string</code>s as
ranges.</p>
<p>Note that both <code>in-string</code> and <code>out-string</code> are subject to the same
form of interpretation, as described below.</p>
</li>
<li>
<p><code>in-string command</code> ...<br />
Bind each <code>in-string</code> to each <code>command</code>. When <code>-R</code> is used,
interpret the <code>in-string</code>s as ranges.</p>
</li>
<li>
<p>[ <code>in-string</code> ]<br />
List key bindings. If an <code>in-string</code> is specified, the binding of
that string in the selected keymap is displayed. Otherwise, all key
bindings in the selected keymap are displayed. (As a special case,
if the <code>-e</code> or <code>-v</code> option is used alone, the keymap is <em>not</em>
displayed - the implicit linking of keymaps is the only thing that
happens.)</p>
<p>When the option <code>-p</code> is used, the <code>in-string</code> must be present. The
listing shows all bindings which have the given key sequence as a
prefix, not including any bindings for the key sequence itself.</p>
<p>When the <code>-L</code> option is used, the list is in the form of <code>bindkey</code>
commands to create the key bindings.</p>
</li>
</ul>
<p>When the <code>-R</code> option is used as noted above, a valid range consists of
two characters, with an optional ‘<code>-</code>’ between them. All characters
between the two specified, inclusive, are bound as specified.</p>
<p>For either <code>in-string</code> or <code>out-string</code>, the following escape sequences
are recognised:</p>
<ul>
<li>
<p><code>\a</code><br />
bell character</p>
</li>
<li>
<p><code>\b</code><br />
backspace</p>
</li>
<li>
<p><code>\e</code>, <code>\E</code><br />
escape</p>
</li>
<li>
<p><code>\f</code><br />
form feed</p>
</li>
<li>
<p><code>\n</code><br />
linefeed (newline)</p>
</li>
<li>
<p><code>\r</code><br />
carriage return</p>
</li>
<li>
<p><code>\t</code><br />
horizontal tab</p>
</li>
<li>
<p><code>\v</code><br />
vertical tab</p>
</li>
<li>
<p><code>\``NNN</code><br />
character code in octal</p>
</li>
<li>
<p><code>\x``NN</code><br />
character code in hexadecimal</p>
</li>
<li>
<p><code>\u``NNNN</code><br />
unicode character code in hexadecimal</p>
</li>
<li>
<p><code>\U``NNNNNNNN</code><br />
unicode character code in hexadecimal</p>
</li>
<li>
<p><code>\M</code>[<code>-</code>]<code>X</code><br />
character with meta bit set</p>
</li>
<li>
<p><code>\C</code>[<code>-</code>]<code>X</code><br />
control character</p>
</li>
<li>
<p><code>^``X</code><br />
control character</p>
</li>
</ul>
<p>In all other cases, ‘<code>\</code>’ escapes the following character. Delete is
written as ‘<code>^?</code>’. Note that ‘<code>\M^?</code>’ and ‘<code>^\M?</code>’ are not the same, and
that (unlike emacs), the bindings ‘<code>\M-``X</code>’ and ‘<code>\e``X</code>’ are entirely
distinct, although they are initialized to the same bindings by
‘<code>bindkey -m</code>’.</p>
<p><span id="index-vared"></span>
<span id="index-parameters_002c-editing"></span>
<span id="index-editing-parameters"></span></p>
<p><code>vared </code>[ <code>-Aacghe</code> ] [ <code>-p</code> <code>prompt</code> ] [ <code>-r</code> <code>rprompt</code> ]</p>
<p><code>      </code>[ <code>-M</code> <code>main-keymap</code> ] [ <code>-m</code> <code>vicmd-keymap</code> ]</p>
<p><code>      </code>[ <code>-i</code> <code>init-widget</code> ] [ <code>-f</code> <code>finish-widget</code> ]</p>
<p><code>      </code>[ <code>-t</code> <code>tty</code> ] <code>name</code></p>
<p>The value of the parameter <code>name</code> is loaded into the edit buffer, and
the line editor is invoked. When the editor exits, <code>name</code> is set to the
string value returned by the editor. When the <code>-c</code> flag is given, the
parameter is created if it doesn’t already exist. The <code>-a</code> flag may be
given with <code>-c</code> to create an array parameter, or the <code>-A</code> flag to create
an associative array. If the type of an existing parameter does not
match the type to be created, the parameter is unset and recreated. The
<code>-g</code> flag may be given to suppress warnings from the
<code>WARN_CREATE_GLOBAL</code> and <code>WARN_NESTED_VAR</code> options.</p>
<p>If an array or array slice is being edited, separator characters as
defined in <code>$IFS</code> will be shown quoted with a backslash, as will
backslashes themselves. Conversely, when the edited text is split into
an array, a backslash quotes an immediately following separator
character or backslash; no other special handling of backslashes, or any
handling of quotes, is performed.</p>
<p>Individual elements of existing array or associative array parameters
may be edited by using subscript syntax on <code>name</code>. New elements are
created automatically, even without <code>-c</code>.</p>
<p>If the <code>-p</code> flag is given, the following string will be taken as the
prompt to display at the left. If the <code>-r</code> flag is given, the following
string gives the prompt to display at the right. If the <code>-h</code> flag is
specified, the history can be accessed from ZLE. If the <code>-e</code> flag is
given, typing <code>^D</code> (Control-D) on an empty line causes <code>vared</code> to exit
immediately with a non-zero return value.</p>
<p>The <code>-M</code> option gives a keymap to link to the <code>main</code> keymap during
editing, and the <code>-m</code> option gives a keymap to link to the <code>vicmd</code>
keymap during editing. For vi-style editing, this allows a pair of
keymaps to override <code>viins</code> and <code>vicmd</code>. For emacs-style editing, only
<code>-M</code> is normally needed but the <code>-m</code> option may still be used. On exit,
the previous keymaps will be restored.</p>
<p><code>Vared</code> calls the usual ‘<code>zle-line-init</code>’ and ‘<code>zle-line-finish</code>’ hooks
before and after it takes control. Using the <code>-i</code> and <code>-f</code> options, it
is possible to replace these with other custom widgets.</p>
<p>If ‘<code>-t</code> <code>tty</code>’ is given, <code>tty</code> is the name of a terminal device to be
used instead of the default <code>/dev/tty</code>. If <code>tty</code> does not refer to a
terminal an error is reported.</p>
<p><span id="index-zle"></span>
<span id="index-widgets_002c-rebinding"></span>
<span id="index-rebinding-widgets"></span>
<span id="index-widgets_002c-binding"></span>
<span id="index-binding-widgets"></span>
<span id="index-widgets_002c-invoking"></span>
<span id="index-invoking-widgets"></span>
<span id="index-widgets_002c-calling"></span>
<span id="index-calling-widgets"></span>
<span id="index-widgets_002c-defining"></span>
<span id="index-defining-widgets"></span></p>
<p><code>zle</code></p>
<p><code>zle</code> <code>-l</code> [ <code>-L</code> | <code>-a</code> ] [ <code>string</code> ... ]</p>
<p><code>zle</code> <code>-D</code> <code>widget</code> ...</p>
<p><code>zle</code> <code>-A</code> <code>old-widget</code> <code>new-widget</code></p>
<p><code>zle</code> <code>-N</code> <code>widget</code> [ <code>function</code> ]</p>
<p><code>zle</code> <code>-f</code> <code>flag</code> [ <code>flag</code>... ]</p>
<p><code>zle</code> <code>-C</code> <code>widget</code> <code>completion-widget</code> <code>function</code></p>
<p><code>zle</code> <code>-R</code> [ <code>-c</code> ] [ <code>display-string</code> ] [ <code>string</code> ... ]</p>
<p><code>zle</code> <code>-M</code> <code>string</code></p>
<p><code>zle</code> <code>-U</code> <code>string</code></p>
<p><code>zle</code> <code>-K</code> <code>keymap</code></p>
<p><code>zle</code> <code>-F</code> [ <code>-L</code> | <code>-w</code> ] [ <code>fd</code> [ <code>handler</code> ] ]</p>
<p><code>zle</code> <code>-I</code></p>
<p><code>zle</code> <code>-T</code> [ <code>tc</code> <code>function</code> | <code>-r</code> <code>tc</code> | <code>-L</code> ]</p>
<p><code>zle</code> <code>widget</code> [ <code>-n</code> <code>num</code> ] [ <code>-Nw</code> ] [ <code>-K</code> <code>keymap</code> ] <code>args</code>
...</p>
<p>The <code>zle</code> builtin performs a number of different actions concerning ZLE.</p>
<p>With no options and no arguments, only the return status will be set. It
is zero if ZLE is currently active and widgets could be invoked using
this builtin command and non-zero otherwise. Note that even if non-zero
status is returned, zle may still be active as part of the completion
system; this does not allow direct calls to ZLE widgets.</p>
<p>Otherwise, which operation it performs depends on its options:</p>
<ul>
<li>
<p><code>-l</code> [ <code>-L</code> | <code>-a</code> ] [ <code>string</code> ]<br />
List all existing user-defined widgets. If the <code>-L</code> option is used,
list in the form of <code>zle</code> commands to create the widgets.</p>
<p>When combined with the <code>-a</code> option, all widget names are listed,
including the builtin ones. In this case the <code>-L</code> option is ignored.</p>
<p>If at least one <code>string</code> is given, and <code>-a</code> is present or <code>-L</code> is
not used, nothing will be printed. The return status will be zero if
all <code>string</code>s are names of existing widgets and non-zero if at least
one <code>string</code> is not a name of a defined widget. If <code>-a</code> is also
present, all widget names are used for the comparison including
builtin widgets, else only user-defined widgets are used.</p>
<p>If at least one <code>string</code> is present and the <code>-L</code> option is used,
user-defined widgets matching any <code>string</code> are listed in the form of
<code>zle</code> commands to create the widgets.</p>
</li>
<li>
<p><code>-D</code> <code>widget</code> ...<br />
Delete the named <code>widget</code>s.</p>
</li>
<li>
<p><code>-A</code> <code>old-widget</code> <code>new-widget</code><br />
Make the <code>new-widget</code> name an alias for <code>old-widget</code>, so that both
names refer to the same widget. The names have equal standing; if
either is deleted, the other remains. If there is already a widget
with the <code>new-widget</code> name, it is deleted.</p>
</li>
<li>
<p><code>-N</code> <code>widget</code> [ <code>function</code> ]<br />
Create a user-defined widget. If there is already a widget with the
specified name, it is overwritten. When the new widget is invoked
from within the editor, the specified shell <code>function</code> is called. If
no function name is specified, it defaults to the same name as the
widget. For further information, see <a href="Zsh-Line-Editor.html#Zle-Widgets">Widgets</a>.</p>
</li>
<li>
<p><code>-f</code> <code>flag</code> [ <code>flag</code>... ]<br />
Set various flags on the running widget. Possible values for <code>flag</code>
are:</p>
<p><code>yank</code> for indicating that the widget has yanked text into the
buffer. If the widget is wrapping an existing internal widget, no
further action is necessary, but if it has inserted the text
manually, then it should also take care to set <code>YANK_START</code> and
<code>YANK_END</code> correctly. <code>yankbefore</code> does the same but is used when
the yanked text appears after the cursor.</p>
<p><code>kill</code> for indicating that text has been killed into the cutbuffer.
When repeatedly invoking a kill widget, text is appended to the
cutbuffer instead of replacing it, but when wrapping such widgets,
it is necessary to call ‘<code>zle -f kill</code>’ to retain this effect.</p>
<p><code>vichange</code> for indicating that the widget represents a vi change
that can be repeated as a whole with ‘<code>vi-repeat-change</code>’. The flag
should be set early in the function before inspecting the value of
<code>NUMERIC</code> or invoking other widgets. This has no effect for a widget
invoked from insert mode. If insert mode is active when the widget
finishes, the change extends until next returning to command mode.</p>
<p><span id="index-completion-widgets_002c-creating"></span></p>
</li>
<li>
<p><code>-C</code> <code>widget</code> <code>completion-widget</code> <code>function</code><br />
Create a user-defined completion widget named <code>widget</code>. The
completion widget will behave like the built-in completion-widget
whose name is given as <code>completion-widget</code>. To generate the
completions, the shell function <code>function</code> will be called. For
further information, see <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a>.</p>
</li>
<li>
<p><code>-R</code> [ <code>-c</code> ] [ <code>display-string</code> ] [ <code>string</code> ... ]<br />
Redisplay the command line; this is to be called from within a
user-defined widget to allow changes to become visible. If a
<code>display-string</code> is given and not empty, this is shown in the status
line (immediately below the line being edited).</p>
<p>If the optional <code>string</code>s are given they are listed below the prompt
in the same way as completion lists are printed. If no <code>string</code>s are
given but the <code>-c</code> option is used such a list is cleared.</p>
<p>Note that this option is only useful for widgets that do not exit
immediately after using it because the strings displayed will be
erased immediately after return from the widget.</p>
<p>This command can safely be called outside user defined widgets; if
zle is active, the display will be refreshed, while if zle is not
active, the command has no effect. In this case there will usually
be no other arguments.</p>
<p>The status is zero if zle was active, else one.</p>
</li>
<li>
<p><code>-M</code> <code>string</code><br />
As with the <code>-R</code> option, the <code>string</code> will be displayed below the
command line; unlike the <code>-R</code> option, the string will not be put
into the status line but will instead be printed normally below the
prompt. This means that the <code>string</code> will still be displayed after
the widget returns (until it is overwritten by subsequent commands).</p>
</li>
<li>
<p><code>-U</code> <code>string</code><br />
This pushes the characters in the <code>string</code> onto the input stack of
ZLE. After the widget currently executed finishes ZLE will behave as
if the characters in the <code>string</code> were typed by the user.</p>
<p>As ZLE uses a stack, if this option is used repeatedly the last
string pushed onto the stack will be processed first. However, the
characters in each <code>string</code> will be processed in the order in which
they appear in the string.</p>
</li>
<li>
<p><code>-K</code> <code>keymap</code><br />
Selects the keymap named <code>keymap</code>. An error message will be
displayed if there is no such keymap.</p>
<p>This keymap selection affects the interpretation of following
keystrokes within this invocation of ZLE. Any following invocation
(e.g., the next command line) will start as usual with the ‘<code>main</code>’
keymap selected.</p>
</li>
<li>
<p><code>-F</code> [ <code>-L</code> | <code>-w</code> ] [ <code>fd</code> [ <code>handler</code> ] ]<br />
Only available if your system supports one of the ‘poll’ or ‘select’
system calls; most modern systems do.</p>
<p>Installs <code>handler</code> (the name of a shell function) to handle input
from file descriptor <code>fd</code>. Installing a handler for an <code>fd</code> which is
already handled causes the existing handler to be replaced. Any
number of handlers for any number of readable file descriptors may
be installed. Note that zle makes no attempt to check whether this
<code>fd</code> is actually readable when installing the handler. The user must
make their own arrangements for handling the file descriptor when
zle is not active.</p>
<p>When zle is attempting to read data, it will examine both the
terminal and the list of handled <code>fd</code>’s. If data becomes available
on a handled <code>fd</code>, zle calls <code>handler</code> with the fd which is ready
for reading as the first argument. Under normal circumstances this
is the only argument, but if an error was detected, a second
argument provides details: ‘<code>hup</code>’ for a disconnect, ‘<code>nval</code>’ for a
closed or otherwise invalid descriptor, or ‘<code>err</code>’ for any other
condition. Systems that support only the ‘select’ system call always
use ‘<code>err</code>’.</p>
<p>If the option <code>-w</code> is also given, the <code>handler</code> is instead a line
editor widget, typically a shell function made into a widget using
‘<code>zle -N</code>’. In that case <code>handler</code> can use all the facilities of
zle to update the current editing line. Note, however, that as
handling <code>fd</code> takes place at a low level changes to the display will
not automatically appear; the widget should call ‘<code>zle -R</code>’ to force
redisplay. As of this writing, widget handlers only support a single
argument and thus are never passed a string for error state, so
widgets must be prepared to test the descriptor themselves.</p>
<p>If either type of handler produces output to the terminal, it should
call ‘<code>zle -I</code>’ before doing so (see below). Handlers should not
attempt to read from the terminal.</p>
<p>If no <code>handler</code> is given, but an <code>fd</code> is present, any handler for
that <code>fd</code> is removed. If there is none, an error message is printed
and status 1 is returned.</p>
<p>If no arguments are given, or the <code>-L</code> option is supplied, a list of
handlers is printed in a form which can be stored for later
execution.</p>
<p>An <code>fd</code> (but not a <code>handler</code>) may optionally be given with the <code>-L</code>
option; in this case, the function will list the handler if any,
else silently return status 1.</p>
<p>Note that this feature should be used with care. Activity on one of
the <code>fd</code>’s which is not properly handled can cause the terminal to
become unusable. Removing an <code>fd</code> handler from within a signal trap
may cause</p>
<p>Here is a simple example of using this feature. A connection to a
remote TCP port is created using the ztcp command; see <a href="Zsh-Modules.html#The-zsh_002fnet_002ftcp-Module">The
zsh/net/tcp
Module</a>. Then a
handler is installed which simply prints out any data which arrives
on this connection. Note that ‘select’ will indicate that the file
descriptor needs handling if the remote side has closed the
connection; we handle that by testing for a failed read.</p>
<div class="example">
<pre><code class="language-example">if ztcp pwspc 2811; then
tcpfd=$REPLY
handler() {
zle -I
local line
if ! read -r line &lt;&amp;$1; then
# select marks this fd if we reach EOF,
# so handle this specially.
print &quot;[Read on fd $1 failed, removing.]&quot; &gt;&amp;2
zle -F $1
return 1
fi
print -r - $line
}
zle -F $tcpfd handler
fi
</code></pre>
</div>
</li>
<li>
<p><code>-I</code><br />
Unusually, this option is most useful outside ordinary widget
functions, though it may be used within if normal output to the
terminal is required. It invalidates the current zle display in
preparation for output; typically this will be from a trap function.
It has no effect if zle is not active. When a trap exits, the shell
checks to see if the display needs restoring, hence the following
will print output in such a way as not to disturb the line being
edited:</p>
<div class="example">
<pre><code class="language-example">TRAPUSR1() {
# Invalidate zle display
[[ -o zle ]] &amp;&amp; zle -I
# Show output
print Hello
}
</code></pre>
</div>
<p>In general, the trap function may need to test whether zle is active
before using this method (as shown in the example), since the
<code>zsh/zle</code> module may not even be loaded; if it is not, the command
can be skipped.</p>
<p>It is possible to call ‘<code>zle -I</code>’ several times before control is
returned to the editor; the display will only be invalidated the
first time to minimise disruption.</p>
<p>Note that there are normally better ways of manipulating the display
from within zle widgets; see, for example, ‘<code>zle -R</code>’ above.</p>
<p>The returned status is zero if zle was invalidated, even though this
may have been by a previous call to ‘<code>zle -I</code>’ or by a system
notification. To test if a zle widget may be called at this point,
execute <code>zle</code> with no arguments and examine the return status.</p>
</li>
<li>
<p><code>-T</code><br />
This is used to add, list or remove internal transformations on the
processing performed by the line editor. It is typically used only
for debugging or testing and is therefore of little interest to the
general user.</p>
<p>‘<code>zle -T</code> <code>transformation</code> <code>func</code>’ specifies that the given
<code>transformation</code> (see below) is effected by shell function <code>func</code>.</p>
<p>‘<code>zle -Tr</code> <code>transformation</code>’ removes the given <code>transformation</code> if
it was present (it is not an error if none was).</p>
<p>‘<code>zle -TL</code>’ can be used to list all transformations currently in
operation.</p>
<p>Currently the only transformation is <code>tc</code>. This is used instead of
outputting termcap codes to the terminal. When the transformation is
in operation the shell function is passed the termcap code that
would be output as its first argument; if the operation required a
numeric argument, that is passed as a second argument. The function
should set the shell variable <code>REPLY</code> to the transformed termcap
code. Typically this is used to produce some simply formatted
version of the code and optional argument for debugging or testing.
Note that this transformation is not applied to other non-printing
characters such as carriage returns and newlines.</p>
</li>
<li>
<p><code>widget</code> [ <code>-n</code> <code>num</code> ] [ <code>-Nw</code> ] [ <code>-K</code> <code>keymap</code> ] <code>args</code>
...<br />
Invoke the specified <code>widget</code>. This can only be done when ZLE is
active; normally this will be within a user-defined widget.</p>
<p>With the options <code>-n</code> and <code>-N</code>, the current numeric argument will be
saved and then restored after the call to <code>widget</code>; ‘<code>-n</code> <code>num</code>’
sets the numeric argument temporarily to <code>num</code>, while ‘<code>-N</code>’ sets it
to the default, i.e. as if there were none.</p>
<p>With the option <code>-K</code>, <code>keymap</code> will be used as the current keymap
during the execution of the widget. The previous keymap will be
restored when the widget exits.</p>
<p>Normally, calling a widget in this way does not set the special
parameter <code>WIDGET</code> and related parameters, so that the environment
appears as if the top-level widget called by the user were still
active. With the option <code>-w</code>, <code>WIDGET</code> and related parameters are
set to reflect the widget being executed by the <code>zle</code> call.</p>
<p>Any further arguments will be passed to the widget; note that as
standard argument handling is performed, any general argument list
should be preceded by <code>-``-</code>. If it is a shell function, these are
passed down as positional parameters; for builtin widgets it is up
to the widget in question what it does with them. Currently
arguments are only handled by the incremental-search commands, the
<code>history-search-forward</code> and <code>-backward</code> and the corresponding
functions prefixed by <code>vi-</code>, and by <code>universal-argument</code>. No error
is flagged if the command does not use the arguments, or only uses
some of them.</p>
<p>The return status reflects the success or failure of the operation
carried out by the widget, or if it is a user-defined widget the
return status of the shell function.</p>
<p>A non-zero return status causes the shell to beep when the widget
exits, unless the <code>BEEP</code> options was unset or the widget was called
via the <code>zle</code> command. Thus if a user defined widget requires an
immediate beep, it should call the <code>beep</code> widget directly.</p>
</li>
</ul>
<hr />
<p><span id="Zle-Widgets"></span> <span id="Widgets-1"></span></p>
<h2 id="184-widgets"><a class="header" href="#184-widgets">18.4 Widgets</a></h2>
<p><span id="index-widgets"></span></p>
<p>All actions in the editor are performed by ‘widgets’. A widget’s job is
simply to perform some small action. The ZLE commands that key sequences
in keymaps are bound to are in fact widgets. Widgets can be user-defined
or built in.</p>
<p>The standard widgets built into ZLE are listed in Standard Widgets
below. Other built-in widgets can be defined by other modules (see <a href="Zsh-Modules.html#Zsh-Modules">Zsh
Modules</a>). Each built-in widget has two
names: its normal canonical name, and the same name preceded by a ‘<code>.</code>’.
The ‘<code>.</code>’ name is special: it can’t be rebound to a different widget.
This makes the widget available even when its usual name has been
redefined.</p>
<p>User-defined widgets are defined using ‘<code>zle -N</code>’, and implemented as
shell functions. When the widget is executed, the corresponding shell
function is executed, and can perform editing (or other) actions. It is
recommended that user-defined widgets should not have names starting
with ‘<code>.</code>’.</p>
<hr />
<p><span id="User_002dDefined-Widgets"></span></p>
<h2 id="185-user-defined-widgets"><a class="header" href="#185-user-defined-widgets">18.5 User-Defined Widgets</a></h2>
<p><span id="index-widgets_002c-user_002ddefined"></span></p>
<p>User-defined widgets, being implemented as shell functions, can execute
any normal shell command. They can also run other widgets (whether
built-in or user-defined) using the <code>zle</code> builtin command. The standard
input of the function is redirected from /dev/null to prevent external
commands from unintentionally blocking ZLE by reading from the terminal,
but <code>read -k</code> or <code>read -q</code> can be used to read characters. Finally, they
can examine and edit the ZLE buffer being edited by reading and setting
the special parameters described below.</p>
<p><span id="index-parameters_002c-editor"></span>
<span id="index-parameters_002c-zle"></span></p>
<p>These special parameters are always available in widget functions, but
are not in any way special outside ZLE. If they have some normal value
outside ZLE, that value is temporarily inaccessible, but will return
when the widget function exits. These special parameters in fact have
local scope, like parameters created in a function using <code>local</code>.</p>
<p>Inside completion widgets and traps called while ZLE is active, these
parameters are available read-only.</p>
<p>Note that the parameters appear as local to any ZLE widget in which they
appear. Hence if it is desired to override them this needs to be done
within a nested function:</p>
<div class="example">
<pre><code class="language-example">widget-function() {
# $WIDGET here refers to the special variable
# that is local inside widget-function
() {
# This anonymous nested function allows WIDGET
# to be used as a local variable. The -h
# removes the special status of the variable.
local -h WIDGET
}
}
</code></pre>
</div>
<p><span id="index-BUFFER"></span></p>
<p><code>BUFFER</code> (scalar)</p>
<p>The entire contents of the edit buffer. If it is written to, the cursor
remains at the same offset, unless that would put it outside the buffer.</p>
<p><span id="index-BUFFERLINES"></span></p>
<p><code>BUFFERLINES</code> (integer)</p>
<p>The number of screen lines needed for the edit buffer currently
displayed on screen (i.e. without any changes to the preceding
parameters done after the last redisplay); read-only.</p>
<p><span id="index-CONTEXT"></span></p>
<p><code>CONTEXT</code> (scalar)</p>
<p>The context in which zle was called to read a line; read-only. One of
the values:</p>
<ul>
<li>
<p><code>start</code><br />
The start of a command line (at prompt <code>PS1</code>).</p>
</li>
<li>
<p><code>cont</code><br />
A continuation to a command line (at prompt <code>PS2</code>).</p>
</li>
<li>
<p><code>select</code><br />
In a <code>select</code> loop (at prompt <code>PS3</code>).</p>
</li>
<li>
<p><code>vared</code><br />
Editing a variable in <code>vared</code>.</p>
</li>
</ul>
<p><span id="index-CURSOR"></span></p>
<p><code>CURSOR</code> (integer)</p>
<p>The offset of the cursor, within the edit buffer. This is in the range 0
to <code>$#BUFFER</code>, and is by definition equal to <code>$#LBUFFER</code>. Attempts to
move the cursor outside the buffer will result in the cursor being moved
to the appropriate end of the buffer.</p>
<p><span id="index-CUTBUFFER"></span></p>
<p><code>CUTBUFFER</code> (scalar)</p>
<p>The last item cut using one of the ‘<code>kill-</code>’ commands; the string which
the next yank would insert in the line. Later entries in the kill ring
are in the array <code>killring</code>. Note that the command ‘<code>zle copy-region-as-kill</code> <code>string</code>’ can be used to set the text of the cut
buffer from a shell function and cycle the kill ring in the same way as
interactively killing text.</p>
<p><span id="index-HISTNO"></span></p>
<p><code>HISTNO</code> (integer)</p>
<p>The current history number. Setting this has the same effect as moving
up or down in the history to the corresponding history line. An attempt
to set it is ignored if the line is not stored in the history. Note this
is not the same as the parameter <code>HISTCMD</code>, which always gives the
number of the history line being added to the main shell’s history.
<code>HISTNO</code> refers to the line being retrieved within zle.</p>
<p><span id="index-ISEARCHMATCH_005fACTIVE"></span>
<span id="index-ISEARCHMATCH_005fSTART"></span>
<span id="index-ISEARCHMATCH_005fEND"></span></p>
<p><code>ISEARCHMATCH_ACTIVE</code> (integer)</p>
<p><code>ISEARCHMATCH_START</code> (integer)</p>
<p><code>ISEARCHMATCH_END</code> (integer)</p>
<p><code>ISEARCHMATCH_ACTIVE</code> indicates whether a part of the <code>BUFFER</code> is
currently matched by an incremental search pattern. <code>ISEARCHMATCH_START</code>
and <code>ISEARCHMATCH_END</code> give the location of the matched part and are in
the same units as <code>CURSOR</code>. They are only valid for reading when
<code>ISEARCHMATCH_ACTIVE</code> is non-zero.</p>
<p>All parameters are read-only.</p>
<p><span id="index-KEYMAP"></span></p>
<p><code>KEYMAP</code> (scalar)</p>
<p>The name of the currently selected keymap; read-only.</p>
<p><span id="index-KEYS"></span></p>
<p><code>KEYS</code> (scalar)</p>
<p>The keys typed to invoke this widget, as a literal string; read-only.</p>
<p><span id="index-KEYS_005fQUEUED_005fCOUNT"></span></p>
<p><code>KEYS_QUEUED_COUNT</code> (integer)</p>
<p>The number of bytes pushed back to the input queue and therefore
available for reading immediately before any I/O is done; read-only. See
also <code>PENDING</code>; the two values are distinct.</p>
<p><span id="index-killring"></span></p>
<p><code>killring</code> (array)</p>
<p>The array of previously killed items, with the most recently killed
first. This gives the items that would be retrieved by a <code>yank-pop</code> in
the same order. Note, however, that the most recently killed item is in
<code>$CUTBUFFER</code>; <code>$killring</code> shows the array of previous entries.</p>
<p>The default size for the kill ring is eight, however the length may be
changed by normal array operations. Any empty string in the kill ring is
ignored by the <code>yank-pop</code> command, hence the size of the array
effectively sets the maximum length of the kill ring, while the number
of non-zero strings gives the current length, both as seen by the user
at the command line.</p>
<p><span id="index-LASTABORTEDSEARCH"></span></p>
<p><code>LASTABORTEDSEARCH</code> (scalar)</p>
<p>The last search string used by an interactive search that was aborted by
the user (status 3 returned by the search widget).</p>
<p><span id="index-LASTSEARCH"></span></p>
<p><code>LASTSEARCH</code> (scalar)</p>
<p>The last search string used by an interactive search; read-only. This is
set even if the search failed (status 0, 1 or 2 returned by the search
widget), but not if it was aborted by the user.</p>
<p><span id="index-LASTWIDGET"></span></p>
<p><code>LASTWIDGET</code> (scalar)</p>
<p>The name of the last widget that was executed; read-only.</p>
<p><span id="index-LBUFFER"></span></p>
<p><code>LBUFFER</code> (scalar)</p>
<p>The part of the buffer that lies to the left of the cursor position. If
it is assigned to, only that part of the buffer is replaced, and the
cursor remains between the new <code>$LBUFFER</code> and the old <code>$RBUFFER</code>.</p>
<p><span id="index-MARK"></span></p>
<p><code>MARK</code> (integer)</p>
<p>Like <code>CURSOR</code>, but for the mark. With vi-mode operators that wait for a
movement command to select a region of text, setting <code>MARK</code> allows the
selection to extend in both directions from the initial cursor position.</p>
<p><span id="index-NUMERIC"></span></p>
<p><code>NUMERIC</code> (integer)</p>
<p>The numeric argument. If no numeric argument was given, this parameter
is unset. When this is set inside a widget function, builtin widgets
called with the <code>zle</code> builtin command will use the value assigned. If it
is unset inside a widget function, builtin widgets called behave as if
no numeric argument was given.</p>
<p><span id="index-PENDING"></span></p>
<p><code>PENDING</code> (integer)</p>
<p>The number of bytes pending for input, i.e. the number of bytes which
have already been typed and can immediately be read. On systems where
the shell is not able to get this information, this parameter will
always have a value of zero. Read-only. See also <code>KEYS_QUEUED_COUNT</code>;
the two values are distinct.</p>
<p><span id="index-PREBUFFER"></span></p>
<p><code>PREBUFFER</code> (scalar)</p>
<p>In a multi-line input at the secondary prompt, this read-only parameter
contains the contents of the lines before the one the cursor is
currently in.</p>
<p><span id="index-PREDISPLAY"></span></p>
<p><code>PREDISPLAY</code> (scalar)</p>
<p>does not have to be a complete line; to display a complete line, a
newline must be appended explicitly. The text is reset on each new
invocation (but not recursive invocation) of zle.</p>
<p><span id="index-POSTDISPLAY"></span></p>
<p><code>POSTDISPLAY</code> (scalar)</p>
<p>does not have to be a complete line; to display a complete line, a
newline must be prepended explicitly. The text is reset on each new
invocation (but not recursive invocation) of zle.</p>
<p><span id="index-RBUFFER"></span></p>
<p><code>RBUFFER</code> (scalar)</p>
<p>The part of the buffer that lies to the right of the cursor position. If
it is assigned to, only that part of the buffer is replaced, and the
cursor remains between the old <code>$LBUFFER</code> and the new <code>$RBUFFER</code>.</p>
<p><span id="index-REGION_005fACTIVE"></span></p>
<p><code>REGION_ACTIVE</code> (integer)</p>
<p>Indicates if the region is currently active. It can be assigned 0 or 1
to deactivate and activate the region respectively. A value of 2
activates the region in line-wise mode with the highlighted text
extending for whole lines only; see <a href="Zsh-Line-Editor.html#Character-Highlighting">Character
Highlighting</a>.</p>
<p><span id="index-region_005fhighlight"></span></p>
<p><code>region_highlight</code> (array)</p>
<p>Each element of this array may be set to a string that describes
highlighting for an arbitrary region of the command line that will take
effect the next time the command line is redisplayed. Highlighting and
<code>POSTDISPLAY</code> are possible, but note that the <code>P</code> flag is needed for
character indexing to include <code>PREDISPLAY</code>.</p>
<p>Each string consists of the following parts:</p>
<ul>
<li>Optionally, a ‘<code>P</code>’ to signify that the start and end offset that
follow include any string set by the <code>PREDISPLAY</code> special parameter;
this is needed if the predisplay string itself is to be highlighted.
Whitespace may follow the ‘<code>P</code>’.</li>
<li>A start offset in the same units as <code>CURSOR</code>, terminated by
whitespace.</li>
<li>An end offset in the same units as <code>CURSOR</code>, terminated by
whitespace.</li>
<li>A highlight specification in the same format as used for contexts in
the parameter <code>zle_highlight</code>, see <a href="Zsh-Line-Editor.html#Character-Highlighting">Character
Highlighting</a>; for example, <code>standout</code> or
<code>fg=red,bold</code>.</li>
</ul>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">region_highlight=(&quot;P0 20 bold&quot;)
</code></pre>
</div>
<p>specifies that the first twenty characters of the text including any
predisplay string should be highlighted in bold.</p>
<p>Note that the effect of <code>region_highlight</code> is not saved and disappears
as soon as the line is accepted.</p>
<p>The final highlighting on the command line depends on both
<code>region_highlight</code> and <code>zle_highlight</code>; see <a href="Zsh-Line-Editor.html#Character-Highlighting">Character
Highlighting</a> for details.</p>
<p><span id="index-registers"></span></p>
<p><code>registers</code> (associative array)</p>
<p>The contents of each of the vi register buffers. These are typically set
using <code>vi-set-buffer</code> followed by a delete, change or yank command.</p>
<p><span id="index-SUFFIX_005fACTIVE"></span>
<span id="index-SUFFIX_005fSTART"></span>
<span id="index-SUFFIX_005fEND"></span></p>
<p><code>SUFFIX_ACTIVE</code> (integer)</p>
<p><code>SUFFIX_START</code> (integer)</p>
<p><code>SUFFIX_END</code> (integer)</p>
<p><code>SUFFIX_ACTIVE</code> indicates whether an auto-removable completion suffix is
currently active. <code>SUFFIX_START</code> and <code>SUFFIX_END</code> give the location of
the suffix and are in the same units as <code>CURSOR</code>. They are only valid
for reading when <code>SUFFIX_ACTIVE</code> is non-zero.</p>
<p>All parameters are read-only.</p>
<p><span id="index-UNDO_005fCHANGE_005fNO"></span></p>
<p><code>UNDO_CHANGE_NO</code> (integer)</p>
<p>A number representing the state of the undo history. The only use of
this is passing as an argument to the <code>undo</code> widget in order to undo
back to the recorded point. Read-only.</p>
<p><span id="index-UNDO_005fLIMIT_005fNO"></span></p>
<p><code>UNDO_LIMIT_NO</code> (integer)</p>
<p>A number corresponding to an existing change in the undo history;
compare <code>UNDO_CHANGE_NO</code>. If this is set to a value greater than zero,
the <code>undo</code> command will not allow the line to be undone beyond the given
change number. It is still possible to use ‘<code>zle undo</code> <code>change</code>’ in a
widget to undo beyond that point; in that case, it will not be possible
to undo at all until <code>UNDO_LIMIT_NO</code> is reduced. Set to 0 to disable the
limit.</p>
<p>A typical use of this variable in a widget function is as follows (note
the additional function scope is required):</p>
<div class="example">
<pre><code class="language-example">() {
local UNDO_LIMIT_NO=$UNDO_CHANGE_NO
# Perform some form of recursive edit.
}
</code></pre>
</div>
<p><span id="index-WIDGET"></span></p>
<p><code>WIDGET</code> (scalar)</p>
<p>The name of the widget currently being executed; read-only.</p>
<p><span id="index-WIDGETFUNC"></span></p>
<p><code>WIDGETFUNC</code> (scalar)</p>
<p>The name of the shell function that implements a widget defined with
either <code>zle -N</code> or <code>zle -C</code>. In the former case, this is the second
argument to the <code>zle -N</code> command that defined the widget, or the first
argument if there was no second argument. In the latter case this is the
third argument to the <code>zle -C</code> command that defined the widget.
Read-only.</p>
<p><span id="index-WIDGETSTYLE"></span></p>
<p><code>WIDGETSTYLE</code> (scalar)</p>
<p>Describes the implementation behind the completion widget currently
being executed; the second argument that followed <code>zle -C</code> when the
widget was defined. This is the name of a builtin completion widget. For
widgets defined with <code>zle -N</code> this is set to the empty string.
Read-only.</p>
<p><span id="index-YANK_005fACTIVE"></span>
<span id="index-YANK_005fSTART"></span>
<span id="index-YANK_005fEND"></span></p>
<p><code>YANK_ACTIVE</code> (integer)</p>
<p><code>YANK_START</code> (integer)</p>
<p><code>YANK_END</code> (integer)</p>
<p><code>YANK_ACTIVE</code> indicates whether text has just been yanked (pasted) into
the buffer. <code>YANK_START</code> and <code>YANK_END</code> give the location of the pasted
text and are in the same units as <code>CURSOR</code>. They are only valid for
reading when <code>YANK_ACTIVE</code> is non-zero. They can also be assigned by
widgets that insert text in a yank-like fashion, for example wrappers of
<code>bracketed-paste</code>. See also <code>zle -f</code>.</p>
<p><code>YANK_ACTIVE</code> is read-only.</p>
<p><span id="index-ZLE_005fRECURSIVE"></span></p>
<p><code>ZLE_RECURSIVE</code> (integer)</p>
<p>Usually zero, but incremented inside any instance of <code>recursive-edit</code>.
Hence indicates the current recursion level.</p>
<p><code>ZLE_RECURSIVE</code> is read-only.</p>
<p><span id="index-ZLE_005fSTATE"></span></p>
<p><code>ZLE_STATE</code> (scalar)</p>
<p>Contains a set of space-separated words that describe the current <code>zle</code>
state.</p>
<p>Currently, the states shown are the insert mode as set by the
<code>overwrite-mode</code> or <code>vi-replace</code> widgets and whether history commands
will visit imported entries as controlled by the set-local-history
widget. The string contains ‘<code>insert</code>’ if characters to be inserted on
the command line move existing characters to the right or ‘<code>overwrite</code>’
if characters to be inserted overwrite existing characters. It contains
‘<code>localhistory</code>’ if only local history commands will be visited or
‘<code>globalhistory</code>’ if imported history commands will also be visited.</p>
<p>The substrings are sorted in alphabetical order so that if you want to
test for two specific substrings in a future-proof way, you can do match
by doing:</p>
<div class="example">
<pre><code class="language-example">if [[ $ZLE_STATE == *globalhistory*insert* ]]; then ...; fi
</code></pre>
</div>
<hr />
<p><span id="Special-Widgets"></span></p>
<h3 id="1851-special-widgets"><a class="header" href="#1851-special-widgets">18.5.1 Special Widgets</a></h3>
<p>There are a few user-defined widgets which are special to the shell. If
they do not exist, no special action is taken. The environment provided
is identical to that for any other editing widget.</p>
<p><span id="index-zle_002disearch_002dexit"></span></p>
<p><code>zle-isearch-exit</code></p>
<p>Executed at the end of incremental search at the point where the isearch
prompt is removed from the display. See <code>zle-isearch-update</code> for an
example.</p>
<p><span id="index-zle_002disearch_002dupdate"></span></p>
<p><code>zle-isearch-update</code></p>
<p>Executed within incremental search when the display is about to be
redrawn. Additional output below the incremental search prompt can be
generated by using ‘<code>zle -M</code>’ within the widget. For example,</p>
<div class="example">
<pre><code class="language-example">zle-isearch-update() { zle -M &quot;Line $HISTNO&quot;; }
zle -N zle-isearch-update
</code></pre>
</div>
<p>Note the line output by ‘<code>zle -M</code>’ is not deleted on exit from
incremental search. This can be done from a <code>zle-isearch-exit</code> widget:</p>
<div class="example">
<pre><code class="language-example">zle-isearch-exit() { zle -M &quot;&quot;; }
zle -N zle-isearch-exit
</code></pre>
</div>
<p><span id="index-zle_002dline_002dpre_002dredraw"></span></p>
<p><code>zle-line-pre-redraw</code></p>
<p>Executed whenever the input line is about to be redrawn, providing an
opportunity to update the region_highlight array.</p>
<p><span id="index-zle_002dline_002dinit"></span></p>
<p><code>zle-line-init</code></p>
<p>Executed every time the line editor is started to read a new line of
input. The following example puts the line editor into vi command mode
when it starts up.</p>
<div class="example">
<pre><code class="language-example">zle-line-init() { zle -K vicmd; }
zle -N zle-line-init
</code></pre>
</div>
<p>(The command inside the function sets the keymap directly; it is
equivalent to <code>zle vi-cmd-mode</code>.)</p>
<p><span id="index-zle_002dline_002dfinish"></span></p>
<p><code>zle-line-finish</code></p>
<p>This is similar to <code>zle-line-init</code> but is executed every time the line
editor has finished reading a line of input.</p>
<p><span id="index-zle_002dhistory_002dline_002dset"></span></p>
<p><code>zle-history-line-set</code></p>
<p>Executed when the history line changes.</p>
<p><span id="index-zle_002dkeymap_002dselect"></span></p>
<p><code>zle-keymap-select</code></p>
<p>Executed every time the keymap changes, i.e. the special parameter
<code>KEYMAP</code> is set to a different value, while the line editor is active.
Initialising the keymap when the line editor starts does not cause the
widget to be called.</p>
<p>The value <code>$KEYMAP</code> within the function reflects the new keymap. The old
keymap is passed as the sole argument.</p>
<p>This can be used for detecting switches between the vi command (<code>vicmd</code>)
and insert (usually <code>main</code>) keymaps.</p>
<hr />
<p><span id="Standard-Widgets"></span></p>
<h2 id="186-standard-widgets"><a class="header" href="#186-standard-widgets">18.6 Standard Widgets</a></h2>
<p><span id="index-widgets_002c-standard"></span></p>
<p>The following is a list of all the standard widgets, and their default
bindings in emacs mode, vi command mode and vi insert mode (the
‘<code>emacs</code>’, ‘<code>vicmd</code>’ and ‘<code>viins</code>’ keymaps, respectively).</p>
<p>Note that cursor keys are bound to movement keys in all three keymaps;
the shell assumes that the cursor keys send the key sequences reported
by the terminal-handling library (termcap or terminfo). The key
sequences shown in the list are those based on the VT100, common on many
modern terminals, but in fact these are not necessarily bound. In the
case of the <code>viins</code> keymap, the initial escape character of the
sequences serves also to return to the <code>vicmd</code> keymap: whether this
happens is determined by the <code>KEYTIMEOUT</code> parameter, see
<a href="Parameters.html#Parameters">Parameters</a>.</p>
<hr />
<p><span id="Movement"></span> <span id="Movement-1"></span></p>
<h3 id="1861-movement"><a class="header" href="#1861-movement">18.6.1 Movement</a></h3>
<p><span id="index-vi_002dbackward_002dblank_002dword"></span></p>
<p><code>vi-backward-blank-word</code> (unbound) (<code>B</code>) (unbound)</p>
<p>Move backward one word, where a word is defined as a series of non-blank
characters.</p>
<p><span id="index-vi_002dbackward_002dblank_002dword_002dend"></span></p>
<p><code>vi-backward-blank-word-end</code> (unbound) (<code>gE</code>) (unbound)</p>
<p>Move to the end of the previous word, where a word is defined as a
series of non-blank characters.</p>
<p><span id="index-backward_002dchar"></span></p>
<p><code>backward-char</code> (<code>^B ESC-[D</code>) (unbound) (unbound)</p>
<p>Move backward one character.</p>
<p><span id="index-vi_002dbackward_002dchar"></span></p>
<p><code>vi-backward-char</code> (unbound) (<code>^H h ^?</code>) (<code>ESC-[D</code>)</p>
<p>Move backward one character, without changing lines.</p>
<p><span id="index-backward_002dword"></span></p>
<p><code>backward-word</code> (<code>ESC-B ESC-b</code>) (unbound) (unbound)</p>
<p>Move to the beginning of the previous word.</p>
<p><span id="index-emacs_002dbackward_002dword"></span></p>
<p><code>emacs-backward-word</code></p>
<p>Move to the beginning of the previous word.</p>
<p><span id="index-vi_002dbackward_002dword"></span></p>
<p><code>vi-backward-word</code> (unbound) (<code>b</code>) (unbound)</p>
<p>Move to the beginning of the previous word, vi-style.</p>
<p><span id="index-vi_002dbackward_002dword_002dend"></span></p>
<p><code>vi-backward-word-end</code> (unbound) (<code>ge</code>) (unbound)</p>
<p>Move to the end of the previous word, vi-style.</p>
<p><span id="index-beginning_002dof_002dline"></span></p>
<p><code>beginning-of-line</code> (<code>^A</code>) (unbound) (unbound)</p>
<p>Move to the beginning of the line. If already at the beginning of the
line, move to the beginning of the previous line, if any.</p>
<p><span id="index-vi_002dbeginning_002dof_002dline"></span></p>
<p><code>vi-beginning-of-line</code></p>
<p>Move to the beginning of the line, without changing lines.</p>
<p><span id="index-down_002dline"></span></p>
<p><code>down-line</code> (unbound) (unbound) (unbound)</p>
<p>Move down a line in the buffer.</p>
<p><span id="index-end_002dof_002dline"></span></p>
<p><code>end-of-line</code> (<code>^E</code>) (unbound) (unbound)</p>
<p>Move to the end of the line. If already at the end of the line, move to
the end of the next line, if any.</p>
<p><span id="index-vi_002dend_002dof_002dline"></span></p>
<p><code>vi-end-of-line</code> (unbound) (<code>$</code>) (unbound)</p>
<p>Move to the end of the line. If an argument is given to this command,
the cursor will be moved to the end of the line (argument - 1) lines
down.</p>
<p><span id="index-vi_002dforward_002dblank_002dword"></span></p>
<p><code>vi-forward-blank-word</code> (unbound) (<code>W</code>) (unbound)</p>
<p>Move forward one word, where a word is defined as a series of non-blank
characters.</p>
<p><span id="index-vi_002dforward_002dblank_002dword_002dend"></span></p>
<p><code>vi-forward-blank-word-end</code> (unbound) (<code>E</code>) (unbound)</p>
<p>Move to the end of the current word, or, if at the end of the current
word, to the end of the next word, where a word is defined as a series
of non-blank characters.</p>
<p><span id="index-forward_002dchar"></span></p>
<p><code>forward-char</code> (<code>^F ESC-[C</code>) (unbound) (unbound)</p>
<p>Move forward one character.</p>
<p><span id="index-vi_002dforward_002dchar"></span></p>
<p><code>vi-forward-char</code> (unbound) (<code>space l</code>) (<code>ESC-[C</code>)</p>
<p>Move forward one character.</p>
<p><span id="index-vi_002dfind_002dnext_002dchar"></span></p>
<p><code>vi-find-next-char</code> (<code>^X^F</code>) (<code>f</code>) (unbound)</p>
<p>Read a character from the keyboard, and move to the next occurrence of
it in the line.</p>
<p><span id="index-vi_002dfind_002dnext_002dchar_002dskip"></span></p>
<p><code>vi-find-next-char-skip</code> (unbound) (<code>t</code>) (unbound)</p>
<p>Read a character from the keyboard, and move to the position just before
the next occurrence of it in the line.</p>
<p><span id="index-vi_002dfind_002dprev_002dchar"></span></p>
<p><code>vi-find-prev-char</code> (unbound) (<code>F</code>) (unbound)</p>
<p>Read a character from the keyboard, and move to the previous occurrence
of it in the line.</p>
<p><span id="index-vi_002dfind_002dprev_002dchar_002dskip"></span></p>
<p><code>vi-find-prev-char-skip</code> (unbound) (<code>T</code>) (unbound)</p>
<p>Read a character from the keyboard, and move to the position just after
the previous occurrence of it in the line.</p>
<p><span id="index-vi_002dfirst_002dnon_002dblank"></span></p>
<p><code>vi-first-non-blank</code> (unbound) (<code>^</code>) (unbound)</p>
<p>Move to the first non-blank character in the line.</p>
<p><span id="index-vi_002dforward_002dword"></span></p>
<p><code>vi-forward-word</code> (unbound) (<code>w</code>) (unbound)</p>
<p>Move forward one word, vi-style.</p>
<p><span id="index-forward_002dword"></span></p>
<p><code>forward-word</code> (<code>ESC-F ESC-f</code>) (unbound) (unbound)</p>
<p>Move to the beginning of the next word. The editor’s idea of a word is
specified with the <code>WORDCHARS</code> parameter.</p>
<p><span id="index-emacs_002dforward_002dword"></span></p>
<p><code>emacs-forward-word</code></p>
<p>Move to the end of the next word.</p>
<p><span id="index-vi_002dforward_002dword_002dend"></span></p>
<p><code>vi-forward-word-end</code> (unbound) (<code>e</code>) (unbound)</p>
<p>Move to the end of the next word.</p>
<p><span id="index-vi_002dgoto_002dcolumn"></span></p>
<p><code>vi-goto-column</code> (<code>ESC-|</code>) (<code>|</code>) (unbound)</p>
<p>Move to the column specified by the numeric argument.</p>
<p><span id="index-vi_002dgoto_002dmark"></span></p>
<p><code>vi-goto-mark</code> (unbound) (<code>‘</code>) (unbound)</p>
<p>Move to the specified mark.</p>
<p><span id="index-vi_002dgoto_002dmark_002dline"></span></p>
<p><code>vi-goto-mark-line</code> (unbound) (<code>’</code>) (unbound)</p>
<p>Move to beginning of the line containing the specified mark.</p>
<p><span id="index-vi_002drepeat_002dfind"></span></p>
<p><code>vi-repeat-find</code> (unbound) (<code>;</code>) (unbound)</p>
<p>Repeat the last <code>vi-find</code> command.</p>
<p><span id="index-vi_002drev_002drepeat_002dfind"></span></p>
<p><code>vi-rev-repeat-find</code> (unbound) (<code>,</code>) (unbound)</p>
<p>Repeat the last <code>vi-find</code> command in the opposite direction.</p>
<p><span id="index-up_002dline"></span></p>
<p><code>up-line</code> (unbound) (unbound) (unbound)</p>
<p>Move up a line in the buffer.</p>
<hr />
<p><span id="History-Control"></span> <span id="History-Control-1"></span></p>
<h3 id="1862-history-control"><a class="header" href="#1862-history-control">18.6.2 History Control</a></h3>
<p><span id="index-beginning_002dof_002dbuffer_002dor_002dhistory"></span></p>
<p><code>beginning-of-buffer-or-history</code> (<code>ESC-&lt;</code>) (<code>gg</code>) (unbound)</p>
<p>Move to the beginning of the buffer, or if already there, move to the
first event in the history list.</p>
<p><span id="index-beginning_002dof_002dline_002dhist"></span></p>
<p><code>beginning-of-line-hist</code></p>
<p>Move to the beginning of the line. If already at the beginning of the
buffer, move to the previous history line.</p>
<p><span id="index-beginning_002dof_002dhistory"></span></p>
<p><code>beginning-of-history</code></p>
<p>Move to the first event in the history list.</p>
<p><span id="index-down_002dline_002dor_002dhistory"></span></p>
<p><code>down-line-or-history</code> (<code>^N ESC-[B</code>) (<code>j</code>) (<code>ESC-[B</code>)</p>
<p>Move down a line in the buffer, or if already at the bottom line, move
to the next event in the history list.</p>
<p><span id="index-vi_002ddown_002dline_002dor_002dhistory"></span></p>
<p><code>vi-down-line-or-history</code> (unbound) (<code>+</code>) (unbound)</p>
<p>Move down a line in the buffer, or if already at the bottom line, move
to the next event in the history list. Then move to the first non-blank
character on the line.</p>
<p><span id="index-down_002dline_002dor_002dsearch"></span></p>
<p><code>down-line-or-search</code></p>
<p>Move down a line in the buffer, or if already at the bottom line, search
forward in the history for a line beginning with the first word in the
buffer.</p>
<p>If called from a function by the <code>zle</code> command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.</p>
<p><span id="index-down_002dhistory"></span></p>
<p><code>down-history</code> (unbound) (<code>^N</code>) (unbound)</p>
<p>Move to the next event in the history list.</p>
<p><span id="index-history_002dbeginning_002dsearch_002dbackward"></span></p>
<p><code>history-beginning-search-backward</code></p>
<p>Search backward in the history for a line beginning with the current
line up to the cursor. This leaves the cursor in its original position.</p>
<p><span id="index-end_002dof_002dbuffer_002dor_002dhistory"></span></p>
<p><code>end-of-buffer-or-history</code> (<code>ESC-&gt;</code>) (unbound) (unbound)</p>
<p>Move to the end of the buffer, or if already there, move to the last
event in the history list.</p>
<p><span id="index-end_002dof_002dline_002dhist"></span></p>
<p><code>end-of-line-hist</code></p>
<p>Move to the end of the line. If already at the end of the buffer, move
to the next history line.</p>
<p><span id="index-end_002dof_002dhistory"></span></p>
<p><code>end-of-history</code></p>
<p>Move to the last event in the history list.</p>
<p><span id="index-vi_002dfetch_002dhistory"></span></p>
<p><code>vi-fetch-history</code> (unbound) (<code>G</code>) (unbound)</p>
<p>Fetch the history line specified by the numeric argument. This defaults
to the current history line (i.e. the one that isn’t history yet).</p>
<p><span id="index-history_002dincremental_002dsearch_002dbackward"></span></p>
<p><code>history-incremental-search-backward</code> (<code>^R ^Xr</code>) (unbound) (unbound)</p>
<p>Search backward incrementally for a specified string. The search is
case-insensitive if the search string does not have uppercase letters
and no numeric argument was given. The string may begin with ‘<code>^</code>’ to
anchor the search to the beginning of the line. When called from a
user-defined function returns the following statuses: 0, if the search
succeeded; 1, if the search failed; 2, if the search term was a bad
pattern; 3, if the search was aborted by the <code>send-break</code> command.</p>
<p>A restricted set of editing functions is available in the mini-buffer.
Keys are looked up in the special <code>isearch</code> keymap, and if not found
there in the main keymap (note that by default the <code>isearch</code> keymap is
empty). An interrupt signal, as defined by the stty setting, will stop
the search and go back to the original line. An undefined key will have
the same effect. Note that the following always perform the same task
within incremental searches and cannot be replaced by user defined
widgets, nor can the set of functions be extended. The supported
functions are:</p>
<ul>
<li>
<p><code>accept-and-hold</code><br />
<code>accept-and-infer-next-history</code><br />
<code>accept-line</code><br />
<code>accept-line-and-down-history</code><br />
Perform the usual function after exiting incremental search. The
command line displayed is executed.</p>
</li>
<li>
<p><code>backward-delete-char</code><br />
<code>vi-backward-delete-char</code><br />
Back up one place in the search history. If the search has been
repeated this does not immediately erase a character in the
minibuffer.</p>
</li>
<li>
<p><code>accept-search</code><br />
Exit incremental search, retaining the command line but performing
no further action. Note that this function is not bound by default
and has no effect outside incremental search.</p>
</li>
<li>
<p><code>backward-delete-word</code><br />
<code>backward-kill-word</code><br />
<code>vi-backward-kill-word</code><br />
Back up one character in the minibuffer; if multiple searches have
been performed since the character was inserted the search history
is rewound to the point just before the character was entered. Hence
this has the effect of repeating <code>backward-delete-char</code>.</p>
</li>
<li>
<p><code>clear-screen</code><br />
Clear the screen, remaining in incremental search mode.</p>
</li>
<li>
<p><code>history-incremental-search-backward</code><br />
Find the next occurrence of the contents of the mini-buffer. If the
mini-buffer is empty, the most recent previously used search string
is reinstated.</p>
</li>
<li>
<p><code>history-incremental-search-forward</code><br />
Invert the sense of the search.</p>
</li>
<li>
<p><code>magic-space</code><br />
Inserts a non-magical space.</p>
</li>
<li>
<p><code>quoted-insert</code><br />
<code>vi-quoted-insert</code><br />
Quote the character to insert into the minibuffer.</p>
</li>
<li>
<p><code>redisplay</code><br />
Redisplay the command line, remaining in incremental search mode.</p>
</li>
<li>
<p><code>vi-cmd-mode</code><br />
Select the ‘<code>vicmd</code>’ keymap; the ‘<code>main</code>’ keymap (insert mode) will
be selected initially.</p>
<p>In addition, the modifications that were made while in vi insert
mode are merged to form a single undo event.</p>
</li>
<li>
<p><code>vi-repeat-search</code><br />
<code>vi-rev-repeat-search</code><br />
Repeat the search. The direction of the search is indicated in the
mini-buffer.</p>
</li>
</ul>
<p>Any character that is not bound to one of the above functions, or
<code>self-insert</code> or <code>self-insert-unmeta</code>, will cause the mode to be exited.
The character is then looked up and executed in the keymap in effect at
that point.</p>
<p>When called from a widget function by the <code>zle</code> command, the incremental
search commands can take a string argument. This will be treated as a
string of keys, as for arguments to the <code>bindkey</code> command, and used as
initial input for the command. Any characters in the string which are
unused by the incremental search will be silently ignored. For example,</p>
<div class="example">
<pre><code class="language-example">zle history-incremental-search-backward forceps
</code></pre>
</div>
<p>will search backwards for <code>forceps</code>, leaving the minibuffer containing
the string ‘<code>forceps</code>’.</p>
<p><span id="index-history_002dincremental_002dsearch_002dforward"></span></p>
<p><code>history-incremental-search-forward</code> (<code>^S ^Xs</code>) (unbound) (unbound)</p>
<p>Search forward incrementally for a specified string. The search is
case-insensitive if the search string does not have uppercase letters
and no numeric argument was given. The string may begin with ‘<code>^</code>’ to
anchor the search to the beginning of the line. The functions available
in the mini-buffer are the same as for
<code>history-incremental-search-backward</code>.</p>
<p><span id="index-history_002dincremental_002dpattern_002dsearch_002dbackward"></span>
<span id="index-history_002dincremental_002dpattern_002dsearch_002dforward"></span></p>
<p><code>history-incremental-pattern-search-backward</code></p>
<p><code>history-incremental-pattern-search-forward</code></p>
<p>These widgets behave similarly to the corresponding widgets with no
<code>-pattern</code>, but the search string typed by the user is treated as a
pattern, respecting the current settings of the various options
affecting pattern matching. See <a href="Expansion.html#Filename-Generation">Filename
Generation</a> for a description of
patterns. If no numeric argument was given lowercase letters in the
search string may match uppercase letters in the history. The string may
begin with ‘<code>^</code>’ to anchor the search to the beginning of the line.</p>
<p>The prompt changes to indicate an invalid pattern; this may simply
indicate the pattern is not yet complete.</p>
<p>Note that only non-overlapping matches are reported, so an expression
with wildcards may return fewer matches on a line than are visible by
inspection.</p>
<p><span id="index-history_002dsearch_002dbackward"></span></p>
<p><code>history-search-backward</code> (<code>ESC-P ESC-p</code>) (unbound) (unbound)</p>
<p>Search backward in the history for a line beginning with the first word
in the buffer.</p>
<p>If called from a function by the <code>zle</code> command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.</p>
<p><span id="index-vi_002dhistory_002dsearch_002dbackward"></span></p>
<p><code>vi-history-search-backward</code> (unbound) (<code>/</code>) (unbound)</p>
<p>Search backward in the history for a specified string. The string may
begin with ‘<code>^</code>’ to anchor the search to the beginning of the line.</p>
<p>A restricted set of editing functions is available in the mini-buffer.
An interrupt signal, as defined by the stty setting, will stop the
search. The functions available in the mini-buffer are: <code>accept-line</code>,
<code>backward-delete-char</code>, <code>vi-backward-delete-char</code>, <code>backward-kill-word</code>,
<code>vi-backward-kill-word</code>, <code>clear-screen</code>, <code>redisplay</code>, <code>quoted-insert</code>
and <code>vi-quoted-insert</code>.</p>
<p><code>vi-cmd-mode</code> is treated the same as accept-line, and <code>magic-space</code> is
treated as a space. Any other character that is not bound to self-insert
or self-insert-unmeta will beep and be ignored. If the function is
called from vi command mode, the bindings of the current insert mode
will be used.</p>
<p>If called from a function by the <code>zle</code> command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.</p>
<p><span id="index-history_002dsearch_002dforward"></span></p>
<p><code>history-search-forward</code> (<code>ESC-N ESC-n</code>) (unbound) (unbound)</p>
<p>Search forward in the history for a line beginning with the first word
in the buffer.</p>
<p>If called from a function by the <code>zle</code> command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.</p>
<p><span id="index-vi_002dhistory_002dsearch_002dforward"></span></p>
<p><code>vi-history-search-forward</code> (unbound) (<code>?</code>) (unbound)</p>
<p>Search forward in the history for a specified string. The string may
begin with ‘<code>^</code>’ to anchor the search to the beginning of the line. The
functions available in the mini-buffer are the same as for
<code>vi-history-search-backward</code>. Argument handling is also the same as for
that command.</p>
<p><span id="index-infer_002dnext_002dhistory"></span></p>
<p><code>infer-next-history</code> (<code>^X^N</code>) (unbound) (unbound)</p>
<p>Search in the history list for a line matching the current one and fetch
the event following it.</p>
<p><span id="index-insert_002dlast_002dword"></span></p>
<p><code>insert-last-word</code> (<code>ESC-_ ESC-.</code>) (unbound) (unbound)</p>
<p>Insert the last word from the previous history event at the cursor
position. If a positive numeric argument is given, insert that word from
the end of the previous history event. If the argument is zero or
negative insert that word from the left (zero inserts the previous
command word). Repeating this command replaces the word just inserted
with the last word from the history event prior to the one just used;
numeric arguments can be used in the same way to pick a word from that
event.</p>
<p>When called from a shell function invoked from a user-defined widget,
the command can take one to three arguments. The first argument
specifies a history offset which applies to successive calls to this
widget: if it is -1, the default behaviour is used, while if it is 1,
successive calls will move forwards through the history. The value 0 can
be used to indicate that the history line examined by the previous
execution of the command will be reexamined. Note that negative numbers
should be preceded by a ‘<code>-``-</code>’ argument to avoid confusing them with
options.</p>
<p>If two arguments are given, the second specifies the word on the command
line in normal array index notation (as a more natural alternative to
the numeric argument). Hence 1 is the first word, and -1 (the default)
is the last word.</p>
<p>If a third argument is given, its value is ignored, but it is used to
signify that the history offset is relative to the current history line,
rather than the one remembered after the previous invocations of
<code>insert-last-word</code>.</p>
<p>For example, the default behaviour of the command corresponds to</p>
<div class="example">
<pre><code class="language-example">zle insert-last-word -- -1 -1
</code></pre>
</div>
<p>while the command</p>
<div class="example">
<pre><code class="language-example">zle insert-last-word -- -1 1 -
</code></pre>
</div>
<p>always copies the first word of the line in the history immediately
before the line being edited. This has the side effect that later
invocations of the widget will be relative to that line.</p>
<p><span id="index-vi_002drepeat_002dsearch"></span></p>
<p><code>vi-repeat-search</code> (unbound) (<code>n</code>) (unbound)</p>
<p>Repeat the last vi history search.</p>
<p><span id="index-vi_002drev_002drepeat_002dsearch"></span></p>
<p><code>vi-rev-repeat-search</code> (unbound) (<code>N</code>) (unbound)</p>
<p>Repeat the last vi history search, but in reverse.</p>
<p><span id="index-up_002dline_002dor_002dhistory"></span></p>
<p><code>up-line-or-history</code> (<code>^P ESC-[A</code>) (<code>k</code>) (<code>ESC-[A</code>)</p>
<p>Move up a line in the buffer, or if already at the top line, move to the
previous event in the history list.</p>
<p><span id="index-vi_002dup_002dline_002dor_002dhistory"></span></p>
<p><code>vi-up-line-or-history</code> (unbound) (<code>-</code>) (unbound)</p>
<p>Move up a line in the buffer, or if already at the top line, move to the
previous event in the history list. Then move to the first non-blank
character on the line.</p>
<p><span id="index-up_002dline_002dor_002dsearch"></span></p>
<p><code>up-line-or-search</code></p>
<p>Move up a line in the buffer, or if already at the top line, search
backward in the history for a line beginning with the first word in the
buffer.</p>
<p>If called from a function by the <code>zle</code> command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.</p>
<p><span id="index-up_002dhistory"></span></p>
<p><code>up-history</code> (unbound) (<code>^P</code>) (unbound)</p>
<p>Move to the previous event in the history list.</p>
<p><span id="index-history_002dbeginning_002dsearch_002dforward"></span></p>
<p><code>history-beginning-search-forward</code></p>
<p>Search forward in the history for a line beginning with the current line
up to the cursor. This leaves the cursor in its original position.</p>
<p><span id="index-set_002dlocal_002dhistory"></span></p>
<p><code>set-local-history</code></p>
<p>By default, history movement commands visit the imported lines as well
as the local lines. This widget lets you toggle this on and off, or set
it with the numeric argument. Zero for both local and imported lines and
nonzero for only local lines.</p>
<hr />
<p><span id="Modifying-Text"></span> <span id="Modifying-Text-1"></span></p>
<h3 id="1863-modifying-text"><a class="header" href="#1863-modifying-text">18.6.3 Modifying Text</a></h3>
<p><span id="index-vi_002dadd_002deol"></span></p>
<p><code>vi-add-eol</code> (unbound) (<code>A</code>) (unbound)</p>
<p>Move to the end of the line and enter insert mode.</p>
<p><span id="index-vi_002dadd_002dnext"></span></p>
<p><code>vi-add-next</code> (unbound) (<code>a</code>) (unbound)</p>
<p>Enter insert mode after the current cursor position, without changing
lines.</p>
<p><span id="index-backward_002ddelete_002dchar"></span></p>
<p><code>backward-delete-char</code> (<code>^H ^?</code>) (unbound) (unbound)</p>
<p>Delete the character behind the cursor.</p>
<p><span id="index-vi_002dbackward_002ddelete_002dchar"></span></p>
<p><code>vi-backward-delete-char</code> (unbound) (<code>X</code>) (<code>^H</code>)</p>
<p>Delete the character behind the cursor, without changing lines. If in
insert mode, this won’t delete past the point where insert mode was last
entered.</p>
<p><span id="index-backward_002ddelete_002dword"></span></p>
<p><code>backward-delete-word</code></p>
<p>Delete the word behind the cursor.</p>
<p><span id="index-backward_002dkill_002dline"></span></p>
<p><code>backward-kill-line</code></p>
<p>Kill from the beginning of the line to the cursor position.</p>
<p><span id="index-backward_002dkill_002dword"></span></p>
<p><code>backward-kill-word</code> (<code>^W ESC-^H ESC-^?</code>) (unbound) (unbound)</p>
<p>Kill the word behind the cursor.</p>
<p><span id="index-vi_002dbackward_002dkill_002dword"></span></p>
<p><code>vi-backward-kill-word</code> (unbound) (unbound) (<code>^W</code>)</p>
<p>Kill the word behind the cursor, without going past the point where
insert mode was last entered.</p>
<p><span id="index-capitalize_002dword"></span></p>
<p><code>capitalize-word</code> (<code>ESC-C ESC-c</code>) (unbound) (unbound)</p>
<p>Capitalize the current word and move past it.</p>
<p><span id="index-vi_002dchange"></span></p>
<p><code>vi-change</code> (unbound) (<code>c</code>) (unbound)</p>
<p>Read a movement command from the keyboard, and kill from the cursor
position to the endpoint of the movement. Then enter insert mode. If the
command is <code>vi-change</code>, change the current line.</p>
<p>For compatibility with vi, if the command is <code>vi-forward-word</code> or
<code>vi-forward-blank-word</code>, the whitespace after the word is not included.
If you prefer the more consistent behaviour with the whitespace included
use the following key binding:</p>
<div class="example">
<pre><code class="language-example">bindkey -a -s cw dwi
</code></pre>
</div>
<p><span id="index-vi_002dchange_002deol"></span></p>
<p><code>vi-change-eol</code> (unbound) (<code>C</code>) (unbound)</p>
<p>Kill to the end of the line and enter insert mode.</p>
<p><span id="index-vi_002dchange_002dwhole_002dline"></span></p>
<p><code>vi-change-whole-line</code> (unbound) (<code>S</code>) (unbound)</p>
<p>Kill the current line and enter insert mode.</p>
<p><span id="index-copy_002dregion_002das_002dkill"></span></p>
<p><code>copy-region-as-kill</code> (<code>ESC-W ESC-w</code>) (unbound) (unbound)</p>
<p>Copy the area from the cursor to the mark to the kill buffer.</p>
<p>If called from a ZLE widget function in the form ‘<code>zle copy-region-as-kill</code> <code>string</code>’ then <code>string</code> will be taken as the text
to copy to the kill buffer. The cursor, the mark and the text on the
command line are not used in this case.</p>
<p><span id="index-copy_002dprev_002dword"></span></p>
<p><code>copy-prev-word</code> (<code>ESC-^_</code>) (unbound) (unbound)</p>
<p>Duplicate the word to the left of the cursor.</p>
<p><span id="index-copy_002dprev_002dshell_002dword"></span></p>
<p><code>copy-prev-shell-word</code></p>
<p>Like <code>copy-prev-word</code>, but the word is found by using shell parsing,
whereas <code>copy-prev-word</code> looks for blanks. This makes a difference when
the word is quoted and contains spaces.</p>
<p><span id="index-vi_002ddelete"></span></p>
<p><code>vi-delete</code> (unbound) (<code>d</code>) (unbound)</p>
<p>Read a movement command from the keyboard, and kill from the cursor
position to the endpoint of the movement. If the command is <code>vi-delete</code>,
kill the current line.</p>
<p><span id="index-delete_002dchar"></span></p>
<p><code>delete-char</code></p>
<p>Delete the character under the cursor.</p>
<p><span id="index-vi_002ddelete_002dchar"></span></p>
<p><code>vi-delete-char</code> (unbound) (<code>x</code>) (unbound)</p>
<p>Delete the character under the cursor, without going past the end of the
line.</p>
<p><span id="index-delete_002dword"></span></p>
<p><code>delete-word</code></p>
<p>Delete the current word.</p>
<p><span id="index-down_002dcase_002dword"></span></p>
<p><code>down-case-word</code> (<code>ESC-L ESC-l</code>) (unbound) (unbound)</p>
<p>Convert the current word to all lowercase and move past it.</p>
<p><span id="index-vi_002ddown_002dcase"></span></p>
<p><code>vi-down-case</code> (unbound) (<code>gu</code>) (unbound)</p>
<p>Read a movement command from the keyboard, and convert all characters
from the cursor position to the endpoint of the movement to lowercase.
If the movement command is <code>vi-down-case</code>, swap the case of all
characters on the current line.</p>
<p><span id="index-kill_002dword"></span></p>
<p><code>kill-word</code> (<code>ESC-D ESC-d</code>) (unbound) (unbound)</p>
<p>Kill the current word.</p>
<p><span id="index-gosmacs_002dtranspose_002dchars"></span></p>
<p><code>gosmacs-transpose-chars</code></p>
<p>Exchange the two characters behind the cursor.</p>
<p><span id="index-vi_002dindent"></span></p>
<p><code>vi-indent</code> (unbound) (<code>&gt;</code>) (unbound)</p>
<p>Indent a number of lines.</p>
<p><span id="index-vi_002dinsert"></span></p>
<p><code>vi-insert</code> (unbound) (<code>i</code>) (unbound)</p>
<p>Enter insert mode.</p>
<p><span id="index-vi_002dinsert_002dbol"></span></p>
<p><code>vi-insert-bol</code> (unbound) (<code>I</code>) (unbound)</p>
<p>Move to the first non-blank character on the line and enter insert mode.</p>
<p><span id="index-vi_002djoin"></span></p>
<p><code>vi-join</code> (<code>^X^J</code>) (<code>J</code>) (unbound)</p>
<p>Join the current line with the next one.</p>
<p><span id="index-kill_002dline"></span></p>
<p><code>kill-line</code> (<code>^K</code>) (unbound) (unbound)</p>
<p>Kill from the cursor to the end of the line. If already on the end of
the line, kill the newline character.</p>
<p><span id="index-vi_002dkill_002dline"></span></p>
<p><code>vi-kill-line</code> (unbound) (unbound) (<code>^U</code>)</p>
<p>Kill from the cursor back to wherever insert mode was last entered.</p>
<p><span id="index-vi_002dkill_002deol"></span></p>
<p><code>vi-kill-eol</code> (unbound) (<code>D</code>) (unbound)</p>
<p>Kill from the cursor to the end of the line.</p>
<p><span id="index-kill_002dregion"></span></p>
<p><code>kill-region</code></p>
<p>Kill from the cursor to the mark.</p>
<p><span id="index-kill_002dbuffer"></span></p>
<p><code>kill-buffer</code> (<code>^X^K</code>) (unbound) (unbound)</p>
<p>Kill the entire buffer.</p>
<p><span id="index-kill_002dwhole_002dline"></span></p>
<p><code>kill-whole-line</code> (<code>^U</code>) (unbound) (unbound)</p>
<p>Kill the current line.</p>
<p><span id="index-vi_002dmatch_002dbracket"></span></p>
<p><code>vi-match-bracket</code> (<code>^X^B</code>) (<code>%</code>) (unbound)</p>
<p>Move to the bracket character (one of <code>{}</code>, <code>()</code> or <code>[]</code>) that matches
the one under the cursor. If the cursor is not on a bracket character,
move forward without going past the end of the line to find one, and
then go to the matching bracket.</p>
<p><span id="index-vi_002dopen_002dline_002dabove"></span></p>
<p><code>vi-open-line-above</code> (unbound) (<code>O</code>) (unbound)</p>
<p>Open a line above the cursor and enter insert mode.</p>
<p><span id="index-vi_002dopen_002dline_002dbelow"></span></p>
<p><code>vi-open-line-below</code> (unbound) (<code>o</code>) (unbound)</p>
<p>Open a line below the cursor and enter insert mode.</p>
<p><span id="index-vi_002doper_002dswap_002dcase"></span></p>
<p><code>vi-oper-swap-case</code> (unbound) (<code>g~</code>) (unbound)</p>
<p>Read a movement command from the keyboard, and swap the case of all
characters from the cursor position to the endpoint of the movement. If
the movement command is <code>vi-oper-swap-case</code>, swap the case of all
characters on the current line.</p>
<p><span id="index-overwrite_002dmode"></span></p>
<p><code>overwrite-mode</code> (<code>^X^O</code>) (unbound) (unbound)</p>
<p>Toggle between overwrite mode and insert mode.</p>
<p><span id="index-vi_002dput_002dbefore"></span></p>
<p><code>vi-put-before</code> (unbound) (<code>P</code>) (unbound)</p>
<p>Insert the contents of the kill buffer before the cursor. If the kill
buffer contains a sequence of lines (as opposed to characters), paste it
above the current line.</p>
<p><span id="index-vi_002dput_002dafter"></span></p>
<p><code>vi-put-after</code> (unbound) (<code>p</code>) (unbound)</p>
<p>Insert the contents of the kill buffer after the cursor. If the kill
buffer contains a sequence of lines (as opposed to characters), paste it
below the current line.</p>
<p><span id="index-put_002dreplace_002dselection"></span></p>
<p><code>put-replace-selection</code> (unbound) (unbound) (unbound)</p>
<p>Replace the contents of the current region or selection with the
contents of the kill buffer. If the kill buffer contains a sequence of
lines (as opposed to characters), the current line will be split by the
pasted lines.</p>
<p><span id="index-quoted_002dinsert"></span></p>
<p><code>quoted-insert</code> (<code>^V</code>) (unbound) (unbound)</p>
<p>Insert the next character typed into the buffer literally. An interrupt
character will not be inserted.</p>
<p><span id="index-vi_002dquoted_002dinsert"></span></p>
<p><code>vi-quoted-insert</code> (unbound) (unbound) (<code>^Q ^V</code>)</p>
<p>Display a ‘<code>^</code>’ at the cursor position, and insert the next character
typed into the buffer literally. An interrupt character will not be
inserted.</p>
<p><span id="index-quote_002dline"></span></p>
<p><code>quote-line</code> (<code>ESC-’</code>) (unbound) (unbound)</p>
<p>Quote the current line; that is, put a ‘<code>’</code>’ character at the beginning
and the end, and convert all ‘<code>’</code>’ characters to ‘<code>’\’’</code>’.</p>
<p><span id="index-quote_002dregion"></span></p>
<p><code>quote-region</code> (<code>ESC-&quot;</code>) (unbound) (unbound)</p>
<p>Quote the region from the cursor to the mark.</p>
<p><span id="index-vi_002dreplace"></span></p>
<p><code>vi-replace</code> (unbound) (<code>R</code>) (unbound)</p>
<p>Enter overwrite mode.</p>
<p><span id="index-vi_002drepeat_002dchange"></span></p>
<p><code>vi-repeat-change</code> (unbound) (<code>.</code>) (unbound)</p>
<p>Repeat the last vi mode text modification. If a count was used with the
modification, it is remembered. If a count is given to this command, it
overrides the remembered count, and is remembered for future uses of
this command. The cut buffer specification is similarly remembered.</p>
<p><span id="index-vi_002dreplace_002dchars"></span></p>
<p><code>vi-replace-chars</code> (unbound) (<code>r</code>) (unbound)</p>
<p>Replace the character under the cursor with a character read from the
keyboard.</p>
<p><span id="index-self_002dinsert"></span></p>
<p>Insert a character into the buffer at the cursor position.</p>
<p><span id="index-self_002dinsert_002dunmeta"></span></p>
<p><code>self-insert-unmeta</code> (<code>ESC-^I ESC-^J ESC-^M</code>) (unbound) (unbound)</p>
<p>Insert a character into the buffer after stripping the meta bit and
converting ^M to ^J.</p>
<p><span id="index-vi_002dsubstitute"></span></p>
<p><code>vi-substitute</code> (unbound) (<code>s</code>) (unbound)</p>
<p>Substitute the next character(s).</p>
<p><span id="index-vi_002dswap_002dcase"></span></p>
<p><code>vi-swap-case</code> (unbound) (<code>~</code>) (unbound)</p>
<p>Swap the case of the character under the cursor and move past it.</p>
<p><span id="index-transpose_002dchars"></span></p>
<p><code>transpose-chars</code> (<code>^T</code>) (unbound) (unbound)</p>
<p>Exchange the two characters to the left of the cursor if at end of line,
else exchange the character under the cursor with the character to the
left.</p>
<p><span id="index-transpose_002dwords"></span></p>
<p><code>transpose-words</code> (<code>ESC-T ESC-t</code>) (unbound) (unbound)</p>
<p>Exchange the current word with the one before it.</p>
<p>With a positive numeric argument <em>N</em>, the word around the cursor, or
following it if the cursor is between words, is transposed with the
preceding <em>N</em> words. The cursor is put at the end of the resulting group
of words.</p>
<p>With a negative numeric argument <em>-N</em>, the effect is the same as using a
positive argument <em>N</em> except that the original cursor position is
retained, regardless of how the words are rearranged.</p>
<p><span id="index-vi_002dunindent"></span></p>
<p><code>vi-unindent</code> (unbound) (<code>&lt;</code>) (unbound)</p>
<p>Unindent a number of lines.</p>
<p><span id="index-vi_002dup_002dcase"></span></p>
<p><code>vi-up-case</code> (unbound) (<code>gU</code>) (unbound)</p>
<p>Read a movement command from the keyboard, and convert all characters
from the cursor position to the endpoint of the movement to lowercase.
If the movement command is <code>vi-up-case</code>, swap the case of all characters
on the current line.</p>
<p><span id="index-up_002dcase_002dword"></span></p>
<p><code>up-case-word</code> (<code>ESC-U ESC-u</code>) (unbound) (unbound)</p>
<p>Convert the current word to all caps and move past it.</p>
<p><span id="index-yank"></span></p>
<p><code>yank</code> (<code>^Y</code>) (unbound) (unbound)</p>
<p>Insert the contents of the kill buffer at the cursor position.</p>
<p><span id="index-yank_002dpop"></span></p>
<p><code>yank-pop</code> (<code>ESC-y</code>) (unbound) (unbound)</p>
<p>Remove the text just yanked, rotate the kill-ring (the history of
previously killed text) and yank the new top. Only works following
<code>yank</code>, <code>vi-put-before</code>, <code>vi-put-after</code> or <code>yank-pop</code>.</p>
<p><span id="index-vi_002dyank"></span></p>
<p><code>vi-yank</code> (unbound) (<code>y</code>) (unbound)</p>
<p>Read a movement command from the keyboard, and copy the region from the
cursor position to the endpoint of the movement into the kill buffer. If
the command is <code>vi-yank</code>, copy the current line.</p>
<p><span id="index-vi_002dyank_002dwhole_002dline"></span></p>
<p><code>vi-yank-whole-line</code> (unbound) (<code>Y</code>) (unbound)</p>
<p>Copy the current line into the kill buffer.</p>
<p><span id="index-vi_002dyank_002deol"></span></p>
<p><code>vi-yank-eol</code></p>
<p>Copy the region from the cursor position to the end of the line into the
kill buffer. Arguably, this is what Y should do in vi, but it isn’t what
it actually does.</p>
<hr />
<p><span id="Arguments"></span> <span id="Arguments-1"></span></p>
<h3 id="1864-arguments"><a class="header" href="#1864-arguments">18.6.4 Arguments</a></h3>
<p><span id="index-digit_002dargument"></span></p>
<p><code>digit-argument</code> (<code>ESC-0</code>..<code>ESC-9</code>) (<code>1</code>-<code>9</code>) (unbound)</p>
<p>Start a new numeric argument, or add to the current one. See also
<code>vi-digit-or-beginning-of-line</code>. This only works if bound to a key
sequence ending in a decimal digit.</p>
<p>Inside a widget function, a call to this function treats the last key of
the key sequence which called the widget as the digit.</p>
<p><span id="index-neg_002dargument"></span></p>
<p><code>neg-argument</code> (<code>ESC-``-</code>) (unbound) (unbound)</p>
<p>Changes the sign of the following argument.</p>
<p><span id="index-universal_002dargument"></span></p>
<p><code>universal-argument</code></p>
<p>Multiply the argument of the next command by 4. Alternatively, if this
command is followed by an integer (positive or negative), use that as
the argument for the next command. Thus digits cannot be repeated using
this command. For example, if this command occurs twice, followed
immediately by <code>forward-char</code>, move forward sixteen spaces; if instead
it is followed by <code>-2</code>, then <code>forward-char</code>, move backward two spaces.</p>
<p>Inside a widget function, if passed an argument, i.e. ‘<code>zle universal-argument</code> <code>num</code>’, the numeric argument will be set to <code>num</code>;
this is equivalent to ‘<code>NUMERIC=``num</code>’.</p>
<p><span id="index-argument_002dbase"></span></p>
<p><code>argument-base</code></p>
<p>Use the existing numeric argument as a numeric base, which must be in
the range 2 to 36 inclusive. Subsequent use of <code>digit-argument</code> and
<code>universal-argument</code> will input a new numeric argument in the given
base. The usual hexadecimal convention is used: the letter <code>a</code> or <code>A</code>
corresponds to 10, and so on. Arguments in bases requiring digits from
10 upwards are more conveniently input with <code>universal-argument</code>, since
<code>ESC-a</code> etc. are not usually bound to <code>digit-argument</code>.</p>
<p>The function can be used with a command argument inside a user-defined
widget. The following code sets the base to 16 and lets the user input a
hexadecimal argument until a key out of the digit range is typed:</p>
<div class="example">
<pre><code class="language-example">zle argument-base 16
zle universal-argument
</code></pre>
</div>
<hr />
<p><span id="Completion"></span> <span id="Completion-2"></span></p>
<h3 id="1865-completion"><a class="header" href="#1865-completion">18.6.5 Completion</a></h3>
<p><span id="index-accept_002dand_002dmenu_002dcomplete"></span></p>
<p><code>accept-and-menu-complete</code></p>
<p>In a menu completion, insert the current completion into the buffer, and
advance to the next possible completion.</p>
<p><span id="index-complete_002dword"></span></p>
<p><code>complete-word</code></p>
<p>Attempt completion on the current word.</p>
<p><span id="index-delete_002dchar_002dor_002dlist"></span></p>
<p><code>delete-char-or-list</code> (<code>^D</code>) (unbound) (unbound)</p>
<p>Delete the character under the cursor. If the cursor is at the end of
the line, list possible completions for the current word.</p>
<p><span id="index-expand_002dcmd_002dpath"></span></p>
<p><code>expand-cmd-path</code></p>
<p>Expand the current command to its full pathname.</p>
<p><span id="index-expand_002dor_002dcomplete"></span></p>
<p><code>expand-or-complete</code> (<code>TAB</code>) (unbound) (<code>TAB</code>)</p>
<p>Attempt shell expansion on the current word. If that fails, attempt
completion.</p>
<p><span id="index-expand_002dor_002dcomplete_002dprefix"></span></p>
<p><code>expand-or-complete-prefix</code></p>
<p>Attempt shell expansion on the current word up to cursor.</p>
<p><span id="index-expand_002dhistory"></span></p>
<p><code>expand-history</code> (<code>ESC-space ESC-!</code>) (unbound) (unbound)</p>
<p>Perform history expansion on the edit buffer.</p>
<p><span id="index-expand_002dword"></span></p>
<p><code>expand-word</code> (<code>^X*</code>) (unbound) (unbound)</p>
<p>Attempt shell expansion on the current word.</p>
<p><span id="index-list_002dchoices"></span></p>
<p><code>list-choices</code> (<code>ESC-^D</code>) (<code>^D =</code>) (<code>^D</code>)</p>
<p>List possible completions for the current word.</p>
<p><span id="index-list_002dexpand"></span></p>
<p><code>list-expand</code> (<code>^Xg ^XG</code>) (<code>^G</code>) (<code>^G</code>)</p>
<p>List the expansion of the current word.</p>
<p><span id="index-magic_002dspace"></span></p>
<p><code>magic-space</code></p>
<p>Perform history expansion and insert a space into the buffer. This is
intended to be bound to space.</p>
<p><span id="index-menu_002dcomplete"></span>
<span id="index-MENU_005fCOMPLETE_002c-use-of"></span></p>
<p><code>menu-complete</code></p>
<p>Like <code>complete-word</code>, except that menu completion is used. See the
<code>MENU_COMPLETE</code> option.</p>
<p><span id="index-menu_002dexpand_002dor_002dcomplete"></span></p>
<p><code>menu-expand-or-complete</code></p>
<p>Like <code>expand-or-complete</code>, except that menu completion is used.</p>
<p><span id="index-reverse_002dmenu_002dcomplete"></span></p>
<p><code>reverse-menu-complete</code></p>
<p>Perform menu completion, like <code>menu-complete</code>, except that if a menu
completion is already in progress, move to the <em>previous</em> completion
rather than the next.</p>
<p><span id="index-end_002dof_002dlist"></span></p>
<p><code>end-of-list</code></p>
<p>When a previous completion displayed a list below the prompt, this
widget can be used to move the prompt below the list.</p>
<hr />
<p><span id="Miscellaneous"></span> <span id="Miscellaneous-1"></span></p>
<h3 id="1866-miscellaneous"><a class="header" href="#1866-miscellaneous">18.6.6 Miscellaneous</a></h3>
<p><span id="index-accept_002dand_002dhold"></span></p>
<p><code>accept-and-hold</code> (<code>ESC-A ESC-a</code>) (unbound) (unbound)</p>
<p>Push the contents of the buffer on the buffer stack and execute it.</p>
<p><span id="index-accept_002dand_002dinfer_002dnext_002dhistory"></span></p>
<p><code>accept-and-infer-next-history</code></p>
<p>Execute the contents of the buffer. Then search the history list for a
line matching the current one and push the event following onto the
buffer stack.</p>
<p><span id="index-accept_002dline"></span></p>
<p><code>accept-line</code> (<code>^J ^M</code>) (<code>^J ^M</code>) (<code>^J ^M</code>)</p>
<p>Finish editing the buffer. Normally this causes the buffer to be
executed as a shell command.</p>
<p><span id="index-accept_002dline_002dand_002ddown_002dhistory"></span></p>
<p><code>accept-line-and-down-history</code> (<code>^O</code>) (unbound) (unbound)</p>
<p>Execute the current line, and push the next history event on the buffer
stack.</p>
<p><span id="index-auto_002dsuffix_002dremove"></span></p>
<p><code>auto-suffix-remove</code></p>
<p>If the previous action added a suffix (space, slash, etc.) to the word
on the command line, remove it. Otherwise do nothing. Removing the
suffix ends any active menu completion or menu selection.</p>
<p>This widget is intended to be called from user-defined widgets to
enforce a desired suffix-removal behavior.</p>
<p><span id="index-auto_002dsuffix_002dretain"></span></p>
<p><code>auto-suffix-retain</code></p>
<p>If the previous action added a suffix (space, slash, etc.) to the word
on the command line, force it to be preserved. Otherwise do nothing.
Retaining the suffix ends any active menu completion or menu selection.</p>
<p>This widget is intended to be called from user-defined widgets to
enforce a desired suffix-preservation behavior.</p>
<p><span id="index-beep"></span></p>
<p><code>beep</code></p>
<p>Beep, unless the <code>BEEP</code> option is unset.</p>
<p><span id="index-bracketed_002dpaste"></span></p>
<p><code>bracketed-paste</code></p>
<p>This widget is invoked when text is pasted to the terminal emulator. It
is not intended to be bound to actual keys but instead to the special
sequence generated by the terminal emulator when text is pasted.</p>
<p>When invoked interactively, the pasted text is inserted to the buffer
and placed in the cutbuffer. If a numeric argument is given, shell
quoting will be applied to the pasted text before it is inserted.</p>
<p>When a named buffer is specified with <code>vi-set-buffer</code> (<code>&quot;x</code>), the pasted
text is stored in that named buffer but not inserted.</p>
<p>When called from a widget function as ‘<code>bracketed-paste</code> <code>name</code>‘, the
pasted text is assigned to the variable <code>name</code> and no other processing
is done.</p>
<p>See also the <code>zle_bracketed_paste</code> parameter.</p>
<p><span id="index-vi_002dcmd_002dmode"></span></p>
<p><code>vi-cmd-mode</code> (<code>^X^V</code>) (unbound) (<code>^[</code>)</p>
<p>Enter command mode; that is, select the ‘<code>vicmd</code>’ keymap. Yes, this is
bound by default in emacs mode.</p>
<p><span id="index-vi_002dcaps_002dlock_002dpanic"></span></p>
<p><code>vi-caps-lock-panic</code></p>
<p>Hang until any lowercase key is pressed. This is for vi users without
the mental capacity to keep track of their caps lock key (like the
author).</p>
<p><span id="index-clear_002dscreen"></span></p>
<p><code>clear-screen</code> (<code>^L ESC-^L</code>) (<code>^L</code>) (<code>^L</code>)</p>
<p>Clear the screen and redraw the prompt.</p>
<p><span id="index-deactivate_002dregion"></span></p>
<p><code>deactivate-region</code></p>
<p>Make the current region inactive. This disables vim-style visual
selection mode if it is active.</p>
<p><span id="index-describe_002dkey_002dbriefly"></span></p>
<p><code>describe-key-briefly</code></p>
<p>Reads a key sequence, then prints the function bound to that sequence.</p>
<p><span id="index-exchange_002dpoint_002dand_002dmark"></span></p>
<p><code>exchange-point-and-mark</code> (<code>^X^X</code>) (unbound) (unbound)</p>
<p>Exchange the cursor position (point) with the position of the mark.
Unless a negative numeric argument is given, the region between point
and mark is activated so that it can be highlighted. If a zero numeric
argument is given, the region is activated but point and mark are not
swapped.</p>
<p><span id="index-execute_002dnamed_002dcmd"></span></p>
<p><code>execute-named-cmd</code> (<code>ESC-x</code>) (<code>:</code>) (unbound)</p>
<p>Read the name of an editor command and execute it. Aliasing this widget
with ‘<code>zle -A</code>’ or replacing it with ‘<code>zle -N</code>’ has no effect when
interpreting key bindings, but ‘<code>zle execute-named-cmd</code>’ will invoke
such an alias or replacement.</p>
<p>A restricted set of editing functions is available in the mini-buffer.
Keys are looked up in the special <code>command</code> keymap, and if not found
there in the main keymap. An interrupt signal, as defined by the stty
setting, will abort the function. Note that the following always perform
the same task within the <code>executed-named-cmd</code> environment and cannot be
replaced by user defined widgets, nor can the set of functions be
extended. The allowed functions are: <code>backward-delete-char</code>,
<code>vi-backward-delete-char</code>, <code>clear-screen</code>, <code>redisplay</code>, <code>quoted-insert</code>,
<code>vi-quoted-insert</code>, <code>backward-kill-word</code>, <code>vi-backward-kill-word</code>,
<code>kill-whole-line</code>, <code>vi-kill-line</code>, <code>backward-kill-line</code>, <code>list-choices</code>,
<code>delete-char-or-list</code>, <code>complete-word</code>, <code>accept-line</code>,
<code>expand-or-complete</code> and <code>expand-or-complete-prefix</code>.</p>
<p><code>kill-region</code> kills the last word, and vi-cmd-mode is treated the same
as accept-line. The space and tab characters, if not bound to one of
these functions, will complete the name and then list the possibilities
if the <code>AUTO_LIST</code> option is set. Any other character that is not bound
to <code>self-insert</code> or <code>self-insert-unmeta</code> will beep and be ignored. The
bindings of the current insert mode will be used.</p>
<p>Currently this command may not be redefined or called by name.</p>
<p><span id="index-execute_002dlast_002dnamed_002dcmd"></span></p>
<p><code>execute-last-named-cmd</code> (<code>ESC-z</code>) (unbound) (unbound)</p>
<p>Redo the last function executed with <code>execute-named-cmd</code>.</p>
<p>Like <code>execute-named-cmd</code>, this command may not be redefined, but it may
be called by name.</p>
<p><span id="index-get_002dline"></span></p>
<p><code>get-line</code> (<code>ESC-G ESC-g</code>) (unbound) (unbound)</p>
<p>Pop the top line off the buffer stack and insert it at the cursor
position.</p>
<p><span id="index-pound_002dinsert"></span></p>
<p><code>pound-insert</code> (unbound) (<code>#</code>) (unbound)</p>
<p>If there is no # character at the beginning of the buffer, add one to
the beginning of each line. If there is one, remove a # from each line
that has one. In either case, accept the current line. The
<code>INTERACTIVE_COMMENTS</code> option must be set for this to have any
usefulness.</p>
<p><span id="index-vi_002dpound_002dinsert"></span></p>
<p><code>vi-pound-insert</code></p>
<p>If there is no # character at the beginning of the current line, add
one. If there is one, remove it. The <code>INTERACTIVE_COMMENTS</code> option must
be set for this to have any usefulness.</p>
<p><span id="index-push_002dinput"></span></p>
<p><code>push-input</code></p>
<p>Push the entire current multiline construct onto the buffer stack and
return to the top-level (<code>PS1</code>) prompt. If the current parser construct
is only a single line, this is exactly like <code>push-line</code>. Next time the
editor starts up or is popped with <code>get-line</code>, the construct will be
popped off the top of the buffer stack and loaded into the editing
buffer.</p>
<p><span id="index-push_002dline"></span></p>
<p><code>push-line</code> (<code>^Q ESC-Q ESC-q</code>) (unbound) (unbound)</p>
<p>Push the current buffer onto the buffer stack and clear the buffer. Next
time the editor starts up, the buffer will be popped off the top of the
buffer stack and loaded into the editing buffer.</p>
<p><span id="index-push_002dline_002dor_002dedit"></span></p>
<p><code>push-line-or-edit</code></p>
<p>At the top-level (<code>PS1</code>) prompt, equivalent to <code>push-line</code>. At a
secondary (<code>PS2</code>) prompt, move the entire current multiline construct
into the editor buffer. The latter is equivalent to <code>push-input</code>
followed by <code>get-line</code>.</p>
<p><span id="index-read_002dcommand"></span></p>
<p><code>read-command</code></p>
<p>Only useful from a user-defined widget. A keystroke is read just as in
normal operation, but instead of the command being executed the name of
the command that would be executed is stored in the shell parameter
<code>REPLY</code>. This can be used as the argument of a future <code>zle</code> command. If
the key sequence is not bound, status 1 is returned; typically, however,
<code>REPLY</code> is set to <code>undefined-key</code> to indicate a useless key sequence.</p>
<p><span id="index-recursive_002dedit"></span></p>
<p><code>recursive-edit</code></p>
<p>Only useful from a user-defined widget. At this point in the function,
the editor regains control until one of the standard widgets which would
normally cause zle to exit (typically an <code>accept-line</code> caused by hitting
the return key) is executed. Instead, control returns to the
user-defined widget. The status returned is non-zero if the return was
caused by an error, but the function still continues executing and hence
may tidy up. This makes it safe for the user-defined widget to alter the
command line or key bindings temporarily.</p>
<p>The following widget, <code>caps-lock</code>, serves as an example.</p>
<div class="example">
<pre><code class="language-example">self-insert-ucase() {
LBUFFER+=${(U)KEYS[-1]}
}
integer stat
zle -N self-insert self-insert-ucase
zle -A caps-lock save-caps-lock
zle -A accept-line caps-lock
zle recursive-edit
stat=$?
zle -A .self-insert self-insert
zle -A save-caps-lock caps-lock
zle -D save-caps-lock
(( stat )) &amp;&amp; zle send-break
return $stat
</code></pre>
</div>
<p>This causes typed letters to be inserted capitalised until either
<code>accept-line</code> (i.e. typically the return key) is typed or the
<code>caps-lock</code> widget is invoked again; the later is handled by saving the
old definition of <code>caps-lock</code> as <code>save-caps-lock</code> and then rebinding it
to invoke <code>accept-line</code>. Note that an error from the recursive edit is
detected as a non-zero return status and propagated by using the
<code>send-break</code> widget.</p>
<p><span id="index-redisplay"></span></p>
<p><code>redisplay</code> (unbound) (<code>^R</code>) (<code>^R</code>)</p>
<p>Redisplays the edit buffer.</p>
<p><span id="index-reset_002dprompt"></span></p>
<p><code>reset-prompt</code> (unbound) (unbound) (unbound)</p>
<p>Force the prompts on both the left and right of the screen to be
re-expanded, then redisplay the edit buffer. This reflects changes both
to the prompt variables themselves and changes in the expansion of the
values (for example, changes in time or directory, or changes to the
value of variables referred to by the prompt).</p>
<p>Otherwise, the prompt is only expanded each time zle starts, and when
the display has been interrupted by output from another part of the
shell (such as a job notification) which causes the command line to be
reprinted.</p>
<p><code>reset-prompt</code> doesn’t alter the special parameter <code>LASTWIDGET</code>.</p>
<p><span id="index-send_002dbreak"></span></p>
<p><code>send-break</code> (<code>^G ESC-^G</code>) (unbound) (unbound)</p>
<p>Abort the current editor function, e.g. <code>execute-named-command</code>, or the
editor itself, e.g. if you are in <code>vared</code>. Otherwise abort the parsing
of the current line; in this case the aborted line is available in the
shell variable <code>ZLE_LINE_ABORTED</code>. If the editor is aborted from within
<code>vared</code>, the variable <code>ZLE_VARED_ABORTED</code> is set.</p>
<p><span id="index-run_002dhelp"></span></p>
<p><code>run-help</code> (<code>ESC-H ESC-h</code>) (unbound) (unbound)</p>
<p>Push the buffer onto the buffer stack, and execute the command
‘<code>run-help</code> <code>cmd</code>’, where <code>cmd</code> is the current command. <code>run-help</code> is
normally aliased to <code>man</code>.</p>
<p><span id="index-vi_002dset_002dbuffer"></span></p>
<p><code>vi-set-buffer</code> (unbound) (<code>&quot;</code>) (unbound)</p>
<p>Specify a buffer to be used in the following command. There are 37
buffers that can be specified: the 26 ‘named’ buffers <code>&quot;a</code> to <code>&quot;z</code>, the
‘yank’ buffer <code>&quot;0</code>, the nine ‘queued’ buffers <code>&quot;1</code> to <code>&quot;9</code> and the
‘black hole’ buffer <code>&quot;_</code>. The named buffers can also be specified as
<code>&quot;A</code> to <code>&quot;Z</code>.</p>
<p>When a buffer is specified for a cut, change or yank command, the text
concerned replaces the previous contents of the specified buffer. If a
named buffer is specified using a capital, the newly cut text is
appended to the buffer instead of overwriting it. When using the <code>&quot;_</code>
buffer, nothing happens. This can be useful for deleting text without
affecting any buffers.</p>
<p>If no buffer is specified for a cut or change command, <code>&quot;1</code> is used, and
the contents of <code>&quot;1</code> to <code>&quot;8</code> are each shifted along one buffer; the
contents of <code>&quot;9</code> is lost. If no buffer is specified for a yank command,
<code>&quot;0</code> is used. Finally, a paste command without a specified buffer will
paste the text from the most recent command regardless of any buffer
that might have been used with that command.</p>
<p>When called from a widget function by the <code>zle</code> command, the buffer can
optionally be specified with an argument. For example,</p>
<div class="example">
<pre><code class="language-example">zle vi-set-buffer A
</code></pre>
</div>
<p><span id="index-vi_002dset_002dmark"></span></p>
<p><code>vi-set-mark</code> (unbound) (<code>m</code>) (unbound)</p>
<p>Set the specified mark at the cursor position.</p>
<p><span id="index-set_002dmark_002dcommand"></span></p>
<p><code>set-mark-command</code> (<code>^@</code>) (unbound) (unbound)</p>
<p>Set the mark at the cursor position. If called with a negative numeric
argument, do not set the mark but deactivate the region so that it is no
longer highlighted (it is still usable for other purposes). Otherwise
the region is marked as active.</p>
<p><span id="index-spell_002dword"></span></p>
<p><code>spell-word</code> (<code>ESC-$ ESC-S ESC-s</code>) (unbound) (unbound)</p>
<p>Attempt spelling correction on the current word.</p>
<p><span id="index-split_002dundo"></span></p>
<p><code>split-undo</code></p>
<p>Breaks the undo sequence at the current change. This is useful in vi
mode as changes made in insert mode are coalesced on entering command
mode. Similarly, <code>undo</code> will normally revert as one all the changes made
by a user-defined widget.</p>
<p><span id="index-undefined_002dkey"></span></p>
<p><code>undefined-key</code></p>
<p>This command is executed when a key sequence that is not bound to any
command is typed. By default it beeps.</p>
<p><span id="index-undo"></span></p>
<p><code>undo</code> (<code>^_ ^Xu ^X^U</code>) (<code>u</code>) (unbound)</p>
<p>Incrementally undo the last text modification. When called from a
user-defined widget, takes an optional argument indicating a previous
state of the undo history as returned by the <code>UNDO_CHANGE_NO</code> variable;
modifications are undone until that state is reached, subject to any
limit imposed by the <code>UNDO_LIMIT_NO</code> variable.</p>
<p>Note that when invoked from vi command mode, the full prior change made
in insert mode is reverted, the changes having been merged when command
mode was selected.</p>
<p><span id="index-redo"></span></p>
<p><code>redo</code> (unbound) (<code>^R</code>) (unbound)</p>
<p>Incrementally redo undone text modifications.</p>
<p><span id="index-vi_002dundo_002dchange"></span></p>
<p><code>vi-undo-change</code> (unbound) (unbound) (unbound)</p>
<p>Undo the last text modification. If repeated, redo the modification.</p>
<p><span id="index-visual_002dmode"></span></p>
<p><code>visual-mode</code> (unbound) (<code>v</code>) (unbound)</p>
<p>Toggle vim-style visual selection mode. If line-wise visual mode is
currently enabled then it is changed to being character-wise. If used
following an operator, it forces the subsequent movement command to be
treated as a character-wise movement.</p>
<p><span id="index-visual_002dline_002dmode"></span></p>
<p><code>visual-line-mode</code> (unbound) (<code>V</code>) (unbound)</p>
<p>Toggle vim-style line-wise visual selection mode. If character-wise
visual mode is currently enabled then it is changed to being line-wise.
If used following an operator, it forces the subsequent movement command
to be treated as a line-wise movement.</p>
<p><span id="index-what_002dcursor_002dposition"></span></p>
<p><code>what-cursor-position</code> (<code>^X=</code>) (<code>ga</code>) (unbound)</p>
<p>Print the character under the cursor, its code as an octal, decimal and
hexadecimal number, the current cursor position within the buffer and
the column of the cursor in the current line.</p>
<p><span id="index-where_002dis"></span></p>
<p><code>where-is</code></p>
<p>Read the name of an editor command and print the listing of key
sequences that invoke the specified command. A restricted set of editing
functions is available in the mini-buffer. Keys are looked up in the
special <code>command</code> keymap, and if not found there in the main keymap.</p>
<p><span id="index-which_002dcommand"></span></p>
<p><code>which-command</code> (<code>ESC-?</code>) (unbound) (unbound)</p>
<p>Push the buffer onto the buffer stack, and execute the command
‘<code>which-command</code> <code>cmd</code>’. where <code>cmd</code> is the current command.
<code>which-command</code> is normally aliased to <code>whence</code>.</p>
<p><span id="index-vi_002ddigit_002dor_002dbeginning_002dof_002dline"></span></p>
<p><code>vi-digit-or-beginning-of-line</code> (unbound) (<code>0</code>) (unbound)</p>
<p>If the last command executed was a digit as part of an argument,
continue the argument. Otherwise, execute vi-beginning-of-line.</p>
<hr />
<p><span id="Text-Objects"></span> <span id="Text-Objects-1"></span></p>
<h3 id="1867-text-objects"><a class="header" href="#1867-text-objects">18.6.7 Text Objects</a></h3>
<p><span id="index-text-objects"></span></p>
<p>Text objects are commands that can be used to select a block of text
according to some criteria. They are a feature of the vim text editor
and so are primarily intended for use with vi operators or from visual
selection mode. However, they can also be used from vi-insert or emacs
mode. Key bindings listed below apply to the <code>viopp</code> and <code>visual</code>
keymaps.</p>
<p><span id="index-select_002da_002dblank_002dword"></span></p>
<p><code>select-a-blank-word</code> (<code>aW</code>)</p>
<p>Select a word including adjacent blanks, where a word is defined as a
series of non-blank characters. With a numeric argument, multiple words
will be selected.</p>
<p><span id="index-select_002da_002dshell_002dword"></span></p>
<p><code>select-a-shell-word</code> (<code>aa</code>)</p>
<p>Select the current command argument applying the normal rules for
quoting.</p>
<p><span id="index-select_002da_002dword"></span></p>
<p><code>select-a-word</code> (<code>aw</code>)</p>
<p>Select a word including adjacent blanks, using the normal vi-style word
definition. With a numeric argument, multiple words will be selected.</p>
<p><span id="index-select_002din_002dblank_002dword"></span></p>
<p><code>select-in-blank-word</code> (<code>iW</code>)</p>
<p>Select a word, where a word is defined as a series of non-blank
characters. With a numeric argument, multiple words will be selected.</p>
<p><span id="index-select_002din_002dshell_002dword"></span></p>
<p><code>select-in-shell-word</code> (<code>ia</code>)</p>
<p>Select the current command argument applying the normal rules for
quoting. If the argument begins and ends with matching quote characters,
these are not included in the selection.</p>
<p><span id="index-select_002din_002dword"></span></p>
<p><code>select-in-word</code> (<code>iw</code>)</p>
<p>Select a word, using the normal vi-style word definition. With a numeric
argument, multiple words will be selected.</p>
<hr />
<p><span id="Character-Highlighting"></span>
<span id="Character-Highlighting-1"></span></p>
<h2 id="187-character-highlighting"><a class="header" href="#187-character-highlighting">18.7 Character Highlighting</a></h2>
<p><span id="index-zle_005fhighlight_002c-setting"></span></p>
<p>The line editor has the ability to highlight characters or regions of
the line that have a particular significance. This is controlled by the
array parameter <code>zle_highlight</code>, if it has been set by the user.</p>
<p>If the parameter contains the single entry <code>none</code> all highlighting is
turned off. Note the parameter is still expected to be an array.</p>
<p>Otherwise each entry of the array should consist of a word indicating a
context for highlighting, then a colon, then a comma-separated list of
the types of highlighting to apply in that context.</p>
<p>The contexts available for highlighting are the following:</p>
<p><span id="index-region_002c-highlighting"></span>
<span id="index-highlighting_002c-region"></span></p>
<p><code>default</code></p>
<p>Any text within the command line not affected by any other highlighting.</p>
<p><code>isearch</code></p>
<p>When one of the incremental history search widgets is active, the area
of the command line matched by the search string or pattern.</p>
<p><code>region</code></p>
<p>The currently selected text. In emacs terminology, this is referred to
as the region and is bounded by the cursor (point) and the mark. The
region is only highlighted if it is active, which is the case after the
mark is modified with <code>set-mark-command</code> or <code>exchange-point-and-mark</code>.
Note that whether or not the region is active has no effect on its use
within emacs style widgets, it simply determines whether it is
highlighted. In vi mode, the region corresponds to selected text in
visual mode.</p>
<p><span id="index-special-characters_002c-highlighting"></span>
<span id="index-highlighting_002c-special-characters"></span></p>
<p><code>special</code></p>
<p>representation but are shown in a special manner by the line editor.
These characters are described below.</p>
<p><span id="index-completion-removable-suffix_002c-highlighting"></span>
<span id="index-suffix_002c-highlighting-removable_002c-in-completion"></span>
<span id="index-removable-suffix_002c-highlighting-in-completion"></span></p>
<p><code>suffix</code></p>
<p>This context is used in completion for characters that are marked as
suffixes that will be removed if the completion ends at that point, the
most obvious example being a slash (<code>/</code>) after a directory name. Note
that suffix removal is configurable; the circumstances under which the
suffix will be removed may differ for different completions.</p>
<p><code>paste</code></p>
<p>Following a command to paste text, the characters that were inserted.</p>
<p>When <code>region_highlight</code> is set, the contexts that describe a region —
<code>isearch</code>, <code>region</code>, <code>suffix</code>, and <code>paste</code> — are applied first, then
<code>region_highlight</code> is applied, then the remaining <code>zle_highlight</code>
contexts are applied. If a particular character is affected by multiple
specifications, the last specification wins.</p>
<p><code>zle_highlight</code> may contain additional fields for controlling how
terminal sequences to change colours are output. Each of the following
is followed by a colon and a string in the same form as for key
bindings. This will not be necessary for the vast majority of terminals
as the defaults shown in parentheses are widely used.</p>
<p><span id="index-escape-sequences_002c-terminal_002c-for-highlighting"></span>
<span id="index-terminal-escape-sequences-for-highlighting"></span></p>
<p><code>fg_start_code</code> (<code>\e[3</code>)</p>
<p>The start of the escape sequence for the foreground colour. This is
followed by one to three ASCII digits representing the colour. Only used
for palette colors, i.e. not 24-bit colors specified via a color
triplet.</p>
<p><code>fg_default_code</code> (<code>9</code>)</p>
<p>The number to use instead of the colour to reset the default foreground
colour.</p>
<p><code>fg_end_code</code> (<code>m</code>)</p>
<p>The end of the escape sequence for the foreground colour.</p>
<p><code>bg_start_code</code> (<code>\e[4</code>)</p>
<p>The start of the escape sequence for the background colour. See
<code>fg_start_code</code> above.</p>
<p><code>bg_default_code</code> (<code>9</code>)</p>
<p>The number to use instead of the colour to reset the default background
colour.</p>
<p><code>bg_end_code</code> (<code>m</code>)</p>
<p>The end of the escape sequence for the background colour.</p>
<p>The available types of highlighting are the following. Note that not all
types of highlighting are available on all terminals:</p>
<ul>
<li>
<p><code>none</code><br />
No highlighting is applied to the given context. It is not useful
for this to appear with other types of highlighting; it is used to
override a default.</p>
</li>
<li>
<p><code>fg=``colour</code><br />
The foreground colour should be set to <code>colour</code>, a decimal integer,
the name of one of the eight most widely-supported colours or as a
‘<code>#</code>’ followed by an RGB triplet in hexadecimal format.</p>
<p>Not all terminals support this and, of those that do, not all
provide facilities to test the support, hence the user should decide
based on the terminal type. Most terminals support the colours
<code>black</code>, <code>red</code>, <code>green</code>, <code>yellow</code>, <code>blue</code>, <code>magenta</code>, <code>cyan</code> and
<code>white</code>, which can be set by name. In addition. <code>default</code> may be
used to set the terminal’s default foreground colour. Abbreviations
are allowed; <code>b</code> or <code>bl</code> selects black. Some terminals may generate
additional colours if the <code>bold</code> attribute is also present.</p>
<p>On recent terminals and on systems with an up-to-date terminal
database the number of colours supported may be tested by the
command ‘<code>echotc Co</code>’; if this succeeds, it indicates a limit on the
number of colours which will be enforced by the line editor. The
number of colours is in any case limited to 256 (i.e. the range 0 to
255).</p>
<p>Some modern terminal emulators have support for 24-bit true colour
(16 million colours). In this case, the hex triplet format can be
used. This consists of a ‘<code>#</code>’ followed by either a three or six
digit hexadecimal number describing the red, green and blue
components of the colour. Hex triplets can also be used with 88 and
256 colour terminals via the <code>zsh/nearcolor</code> module (see <a href="Zsh-Modules.html#The-zsh_002fnearcolor-Module">The
zsh/nearcolor
Module</a>).</p>
<p>Colour is also known as color.</p>
</li>
<li>
<p><code>bg=``colour</code><br />
The background colour should be set to <code>colour</code>. This works
similarly to the foreground colour, except the background is not
usually affected by the bold attribute.</p>
</li>
<li>
<p><code>bold</code><br />
The characters in the given context are shown in a bold font. Not
all terminals distinguish bold fonts.</p>
</li>
<li>
<p><code>standout</code><br />
The characters in the given context are shown in the terminal’s
standout mode. The actual effect is specific to the terminal; on
many terminals it is inverse video. On some such terminals, where
the cursor does not blink it appears with standout mode negated,
making it less than clear where the cursor actually is. On such
terminals one of the other effects may be preferable for
highlighting the region and matched search string.</p>
</li>
<li>
<p><code>underline</code><br />
The characters in the given context are shown underlined. Some
terminals show the foreground in a different colour instead; in this
case whitespace will not be highlighted.</p>
</li>
</ul>
<p>The characters described above as ‘special’ are as follows. The
formatting described here is used irrespective of whether the characters
are highlighted:</p>
<ul>
<li>
<p>ASCII control characters<br />
Control characters in the ASCII range are shown as ‘<code>^</code>’ followed by
the base character.</p>
<p>This item applies to control characters not in the ASCII range, plus
other characters as follows. If the <code>MULTIBYTE</code> option is in effect,
multibyte characters not in the ASCII character set that are
reported as having zero width are treated as combining characters
when the option <code>COMBINING_CHARS</code> is on. If the option is off, or if
a character appears where a combining character is not valid, the
character</p>
<p>angle brackets. The number is the code point of the character in the
wide character set; this may or may not be Unicode, depending on the
operating system.</p>
</li>
<li>
<p>Invalid multibyte characters<br />
If the <code>MULTIBYTE</code> option is in effect, any sequence of one or more
bytes that does not form a valid character in the current character
set is treated as a series of bytes each shown as a special
character. as the bytes are represented as two hexadecimal digits
between angle brackets, as distinct from the four or eight digits
that are used for character set.</p>
<p>Not all systems support this: for it to work, the system’s
representation of wide characters must be code values from the
Universal Character Set, as defined by IS0 10646 (also known as
Unicode).</p>
</li>
<li>
<p>Wrapped double-width characters<br />
When a double-width character appears in the final column of a line,
it is instead shown on the next line. The empty space left in the
original position is highlighted as a special character.</p>
</li>
</ul>
<p>If <code>zle_highlight</code> is not set or no value applies to a particular
context, the defaults applied are equivalent to</p>
<div class="example">
<pre><code class="language-example">zle_highlight=(region:standout special:standout
suffix:bold isearch:underline paste:standout)
</code></pre>
</div>
<p>i.e. both the region and special characters are shown in standout mode.</p>
<p>Within widgets, arbitrary regions may be highlighted by setting the
special array parameter <code>region_highlight</code>; see <a href="Zsh-Line-Editor.html#Zle-Widgets">Widgets</a>.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Completion-Widgets.html#19-completion-widgets">19 Completion Widgets</a>
<ul>
<li><a href="Completion-Widgets.html#191-description">19.1 Description</a></li>
<li><a href="Completion-Widgets.html#192-completion-special-parameters">19.2 Completion Special Parameters</a></li>
<li><a href="Completion-Widgets.html#193-completion-builtin-commands">19.3 Completion Builtin Commands</a></li>
<li><a href="Completion-Widgets.html#194-completion-condition-codes">19.4 Completion Condition Codes</a></li>
<li><a href="Completion-Widgets.html#195-completion-matching-control">19.5 Completion Matching Control</a></li>
<li><a href="Completion-Widgets.html#196-completion-widget-example">19.6 Completion Widget Example</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Completion-Widgets"></span>
<span id="Completion-Widgets-1"></span></p>
<h1 id="19-completion-widgets"><a class="header" href="#19-completion-widgets">19 Completion Widgets</a></h1>
<p><span id="index-completion_002c-widgets"></span>
<span id="index-completion_002c-programmable"></span>
<span id="index-completion_002c-controlling"></span></p>
<hr />
<p><span id="Description-1"></span></p>
<h2 id="191-description"><a class="header" href="#191-description">19.1 Description</a></h2>
<p>The shell’s programmable completion mechanism can be manipulated in two
ways; here the low-level features supporting the newer, function-based
mechanism are defined. A complete set of shell functions based on these
features is described in the next chapter, <a href="Completion-System.html#Completion-System">Completion
System</a>, and users with no
interest in adding to that system (or, potentially, writing their own —
see dictionary entry for ‘hubris’) should skip the current section. The
older system based on the <code>compctl</code> builtin command is described in
<a href="Completion-Using-compctl.html#Completion-Using-compctl">Completion Using
compctl</a>.</p>
<p>Completion widgets are defined by the <code>-C</code> option to the <code>zle</code> builtin
command provided by the <code>zsh/zle</code> module (see <a href="Zsh-Modules.html#The-zsh_002fzle-Module">The zsh/zle
Module</a>). For example,</p>
<div class="example">
<pre><code class="language-example">zle -C complete expand-or-complete completer
</code></pre>
</div>
<p>defines a widget named ‘<code>complete</code>’. The second argument is the name of
any of the builtin widgets that handle completions: <code>complete-word</code>,
<code>expand-or-complete</code>, <code>expand-or-complete-prefix</code>, <code>menu-complete</code>,
<code>menu-expand-or-complete</code>, <code>reverse-menu-complete</code>, <code>list-choices</code>, or
<code>delete-char-or-list</code>. Note that this will still work even if the widget
in question has been re-bound.</p>
<p>When this newly defined widget is bound to a key using the <code>bindkey</code>
builtin command defined in the <code>zsh/zle</code> module (<a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh Line
Editor</a>), typing that key will
call the shell function ‘<code>completer</code>’. This function is responsible for
generating the possible matches using the builtins described below. As
with other ZLE widgets, the function is called with its standard input
closed.</p>
<p>Once the function returns, the completion code takes over control again
and treats the matches in the same manner as the specified builtin
widget, in this case <code>expand-or-complete</code>.</p>
<hr />
<p><span id="Completion-Special-Parameters"></span>
<span id="Completion-Special-Parameters-1"></span></p>
<h2 id="192-completion-special-parameters"><a class="header" href="#192-completion-special-parameters">19.2 Completion Special Parameters</a></h2>
<p>The parameters <code>ZLE_REMOVE_SUFFIX_CHARS</code> and <code>ZLE_SPACE_SUFFIX_CHARS</code>
are used by the completion mechanism, but are not special. See
<a href="Parameters.html#Parameters-Used-By-The-Shell">Parameters Used By The
Shell</a>.</p>
<p>Inside completion widgets, and any functions called from them, some
parameters have special meaning; outside these functions they are not
special to the shell in any way. These parameters are used to pass
information between the completion code and the completion widget. Some
of the builtin commands and the condition codes use or change the
current values of these parameters. Any existing values will be hidden
during execution of completion widgets; except for <code>compstate</code>, the
parameters are reset on each function exit (including nested function
calls from within the completion widget) to the values they had when the
function was entered.</p>
<p><span id="index-CURRENT"></span></p>
<p><code>CURRENT</code></p>
<p>This is the number of the current word, i.e. the word the cursor is
currently on in the <code>words</code> array. Note that this value is only correct
if the <code>ksharrays</code> option is not set.</p>
<p><span id="index-IPREFIX"></span></p>
<p><code>IPREFIX</code></p>
<p>Initially this will be set to the empty string. This parameter functions
like <code>PREFIX</code>; it contains a string which precedes the one in <code>PREFIX</code>
and is not considered part of the list of matches. Typically, a string
is transferred from the beginning of <code>PREFIX</code> to the end of <code>IPREFIX</code>,
for example:</p>
<div class="example">
<pre><code class="language-example">IPREFIX=${PREFIX%%\=*}=
PREFIX=${PREFIX#*=}
</code></pre>
</div>
<p>causes the part of the prefix up to and including the first equal sign
not to be treated as part of a matched string. This can be done
automatically by the <code>compset</code> builtin, see below.</p>
<p><span id="index-ISUFFIX"></span></p>
<p><code>ISUFFIX</code></p>
<p>As <code>IPREFIX</code>, but for a suffix that should not be considered part of the
matches; note that the <code>ISUFFIX</code> string follows the <code>SUFFIX</code> string.</p>
<p><span id="index-PREFIX"></span></p>
<p><code>PREFIX</code></p>
<p>Initially this will be set to the part of the current word from the
beginning of the word up to the position of the cursor; it may be
altered to give a common prefix for all matches.</p>
<p><span id="index-QIPREFIX"></span></p>
<p><code>QIPREFIX</code></p>
<p>This parameter is read-only and contains the quoted string up to the
word being completed. E.g. when completing ‘<code>&quot;foo</code>’, this parameter
contains the double quote. If the <code>-q</code> option of <code>compset</code> is used (see
below), and the original string was ‘<code>&quot;foo bar</code>’ with the cursor on the
‘<code>bar</code>’, this parameter contains ‘<code>&quot;foo </code>’.</p>
<p><span id="index-QISUFFIX"></span></p>
<p><code>QISUFFIX</code></p>
<p>Like <code>QIPREFIX</code>, but containing the suffix.</p>
<p><span id="index-SUFFIX"></span></p>
<p><code>SUFFIX</code></p>
<p>Initially this will be set to the part of the current word from the
cursor position to the end; it may be altered to give a common suffix
for all matches. It is most useful when the option <code>COMPLETE_IN_WORD</code> is
set, as otherwise the whole word on the command line is treated as a
prefix.</p>
<p><span id="index-compstate"></span>
<span id="index-completion-widgets_002c-examining-and-setting-state-in"></span></p>
<p><code>compstate</code></p>
<p>This is an associative array with various keys and values that the
completion code uses to exchange information with the completion widget.
The keys are:</p>
<p><span id="index-all_005fquotes_002c-compstate"></span></p>
<p><code>all_quotes</code></p>
<p>The <code>-q</code> option of the <code>compset</code> builtin command (see below) allows a
quoted string to be broken into separate words; if the cursor is on one
of those words, that word will be completed, possibly invoking ‘<code>compset -q</code>’ recursively. With this key it is possible to test the types of
quoted strings which are currently broken into parts in this fashion.
Its value contains one character for each quoting level. The characters
are a single quote or a double quote for strings quoted with these
characters, a dollars sign for strings quoted with <code>$’``...``’</code> and a
backslash for strings not starting with a quote character. The first
character in the value always corresponds to the innermost quoting
level.</p>
<p><span id="index-context_002c-compstate"></span></p>
<p><code>context</code></p>
<p>This will be set by the completion code to the overall context in which
completion is attempted. Possible values are:</p>
<ul>
<li>
<p><code>array_value</code><br />
when completing inside the value of an array parameter assignment;
in this case the <code>words</code> array contains the words inside the
parentheses.</p>
</li>
<li>
<p><code>brace_parameter</code><br />
when completing the name of a parameter in a parameter expansion
beginning with <code>${</code>. This context will also be set when completing
parameter flags following <code>${(</code>; the full command line argument is
presented and the handler must test the value to be completed to
ascertain that this is the case.</p>
</li>
<li>
<p><code>assign_parameter</code><br />
when completing the name of a parameter in a parameter assignment.</p>
</li>
<li>
<p><code>command</code><br />
when completing for a normal command (either in command position or
for an argument of the command).</p>
</li>
<li>
<p><code>condition</code><br />
when completing inside a ‘<code>[[</code>...<code>]]</code>’ conditional expression; in
this case the <code>words</code> array contains only the words inside the
conditional expression.</p>
</li>
<li>
<p><code>math</code><br />
when completing in a mathematical environment such as a
‘<code>((</code>...<code>))</code>’ construct.</p>
</li>
<li>
<p><code>parameter</code><br />
when completing the name of a parameter in a parameter expansion
beginning with <code>$</code> but not <code>${</code>.</p>
</li>
<li>
<p><code>redirect</code><br />
when completing after a redirection operator.</p>
</li>
<li>
<p><code>subscript</code><br />
when completing inside a parameter subscript.</p>
</li>
<li>
<p><code>value</code><br />
when completing the value of a parameter assignment.</p>
</li>
</ul>
<p><span id="index-exact_002c-compstate"></span></p>
<p><code>exact</code></p>
<p>Controls the behaviour when the <code>REC_EXACT</code> option is set. It will be
set to <code>accept</code> if an exact match would be accepted, and will be unset
otherwise.</p>
<p>If it was set when at least one match equal to the string on the line
was generated, the match is accepted.</p>
<p><span id="index-exact_005fstring_002c-compstate"></span></p>
<p><code>exact_string</code></p>
<p>The string of an exact match if one was found, otherwise unset.</p>
<p><span id="index-ignored_002c-compstate"></span></p>
<p><code>ignored</code></p>
<p>The number of words that were ignored because they matched one of the
patterns given with the <code>-F</code> option to the <code>compadd</code> builtin command.</p>
<p><span id="index-insert_002c-compstate"></span></p>
<p><code>insert</code></p>
<p>This controls the manner in which a match is inserted into the command
line. On entry to the widget function, if it is unset the command line
is not to be changed; if set to <code>unambiguous</code>, any prefix common to all
matches is to be inserted; if set to <code>automenu-unambiguous</code>, the common
prefix is to be inserted and the next invocation of the completion code
may start menu completion (due to the <code>AUTO_MENU</code> option being set); if
set to <code>menu</code> or <code>automenu</code> menu completion will be started for the
matches currently generated (in the latter case this will happen because
the <code>AUTO_MENU</code> is set). The value may also contain the string ‘<code>tab</code>’
when the completion code would normally not really do completion, but
only insert the TAB character.</p>
<p>On exit it may be set to any of the values above (where setting it to
the empty string is the same as unsetting it), or to a number, in which
case the match whose number is given will be inserted into the command
line. Negative numbers count backward from the last match (with ‘<code>-1</code>’
selecting the last match) and out-of-range values are wrapped around, so
that a value of zero selects the last match and a value one more than
the maximum selects the first. Unless the value of this key ends in a
space, the match is inserted as in a menu completion, i.e. without
automatically appending a space.</p>
<p>Both <code>menu</code> and <code>automenu</code> may also specify the number of the match to
insert, given after a colon. For example, ‘<code>menu:2</code>’ says to start menu
completion, beginning with the second match.</p>
<p>Note that a value containing the substring ‘<code>tab</code>’ makes the matches
generated be ignored and only the TAB be inserted.</p>
<p>Finally, it may also be set to <code>all</code>, which makes all matches generated
be inserted into the line.</p>
<p><span id="index-insert_005fpositions_002c-compstate"></span></p>
<p><code>insert_positions</code></p>
<p>When the completion system inserts an unambiguous string into the line,
there may be multiple places where characters are missing or where the
character inserted differs from at least one match. The value of this
key contains a colon separated list of all these positions, as indexes
into the command line.</p>
<p><span id="index-last_005fprompt_002c-compstate"></span></p>
<p><code>last_prompt</code></p>
<p>If this is set to a non-empty string for every match added, the
completion code will move the cursor back to the previous prompt after
the list of completions has been displayed. Initially this is set or
unset according to the <code>ALWAYS_LAST_PROMPT</code> option.</p>
<p><span id="index-list_002c-compstate"></span></p>
<p><code>list</code></p>
<p>This controls whether or how the list of matches will be displayed. If
it is unset or empty they will never be listed; if its value begins with
<code>list</code>, they will always be listed; if it begins with <code>autolist</code> or
<code>ambiguous</code>, they will be listed when the <code>AUTO_LIST</code> or
<code>LIST_AMBIGUOUS</code> options respectively would normally cause them to be.</p>
<p>If the substring <code>force</code> appears in the value, this makes the list be
shown even if there is only one match. Normally, the list would be shown
only if there are at least two matches.</p>
<p>The value contains the substring <code>packed</code> if the <code>LIST_PACKED</code> option is
set. If this substring is given for all matches added to a group, this
group will show the <code>LIST_PACKED</code> behavior. The same is done for the
<code>LIST_ROWS_FIRST</code> option with the substring <code>rows</code>.</p>
<p>Finally, if the value contains the string <code>explanations</code>, only the
explanation strings, if any, will be listed and if it contains
<code>messages</code>, only the messages (added with the <code>-x</code> option of <code>compadd</code>)
will be listed. If it contains both <code>explanations</code> and <code>messages</code> both
kinds of explanation strings will be listed. It will be set
appropriately on entry to a completion widget and may be changed there.</p>
<p><span id="index-list_005flines_002c-compstate"></span></p>
<p><code>list_lines</code></p>
<p>This gives the number of lines that are needed to display the full list
of completions. Note that to calculate the total number of lines to
display you need to add the number of lines needed for the command line
to this value, this is available as the value of the <code>BUFFERLINES</code>
special parameter.</p>
<p><span id="index-list_005fmax_002c-compstate"></span></p>
<p><code>list_max</code></p>
<p>Initially this is set to the value of the <code>LISTMAX</code> parameter. It may be
set to any other value; when the widget exits this value will be used in
the same way as the value of <code>LISTMAX</code>.</p>
<p><span id="index-nmatches_002c-compstate"></span></p>
<p><code>nmatches</code></p>
<p>The number of matches generated and accepted by the completion code so
far.</p>
<p><span id="index-old_005finsert_002c-compstate"></span></p>
<p><code>old_insert</code></p>
<p>On entry to the widget this will be set to the number of the match of an
old list of completions that is currently inserted into the command
line. If no match has been inserted, this is unset.</p>
<p>As with <code>old_list</code>, the value of this key will only be used if it is the
string <code>keep</code>. If it was set to this value by the widget and there was
an old match inserted into the command line, this match will be kept and
if the value of the <code>insert</code> key specifies that another match should be
inserted, this will be inserted after the old one.</p>
<p><span id="index-old_005flist_002c-compstate"></span></p>
<p><code>old_list</code></p>
<p>This is set to <code>yes</code> if there is still a valid list of completions from
a previous completion at the time the widget is invoked. This will
usually be the case if and only if the previous editing operation was a
completion widget or one of the builtin completion functions. If there
is a valid list and it is also currently shown on the screen, the value
of this key is <code>shown</code>.</p>
<p>After the widget has exited the value of this key is only used if it was
set to <code>keep</code>. In this case the completion code will continue to use
this old list. If the widget generated new matches, they will not be
used.</p>
<p><span id="index-parameter_002c-compstate"></span></p>
<p><code>parameter</code></p>
<p>The name of the parameter when completing in a subscript or in the value
of a parameter assignment.</p>
<p><span id="index-pattern_005finsert_002c-compstate"></span></p>
<p><code>pattern_insert</code></p>
<p>Normally this is set to <code>menu</code>, which specifies that menu completion
will be used whenever a set of matches was generated using pattern
matching. If it is set to any other non-empty string by the user and
menu completion is not selected by other option settings, the code will
instead insert any common prefix for the generated matches as with
normal completion.</p>
<p><span id="index-pattern_005fmatch_002c-compstate"></span></p>
<p><code>pattern_match</code></p>
<p>Locally controls the behaviour given by the <code>GLOB_COMPLETE</code> option.
Initially it is set to ‘<code>*</code>’ if and only if the option is set. The
completion widget may set it to this value, to an empty string (which
has the same effect as unsetting it), or to any other non-empty string.
If it is non-empty, unquoted metacharacters on the command line will be
treated as patterns; if it is ‘<code>*</code>’, then additionally a wildcard ‘<code>*</code>’
is assumed at the cursor position; if it is empty or unset,
metacharacters will be treated literally.</p>
<p>Note that the matcher specifications given to the <code>compadd</code> builtin
command are not used if this is set to a non-empty string.</p>
<p><span id="index-quote_002c-compstate"></span></p>
<p><code>quote</code></p>
<p>When completing inside quotes, this contains the quotation character
(i.e. either a single quote, a double quote, or a backtick). Otherwise
it is unset.</p>
<p><span id="index-quoting_002c-compstate"></span></p>
<p><code>quoting</code></p>
<p>When completing inside single quotes, this is set to the string
<code>single</code>; inside double quotes, the string <code>double</code>; inside backticks,
the string <code>backtick</code>. Otherwise it is unset.</p>
<p><span id="index-redirect_002c-compstate"></span></p>
<p><code>redirect</code></p>
<p>The redirection operator when completing in a redirection position, i.e.
one of <code>&lt;</code>, <code>&gt;</code>, etc.</p>
<p><span id="index-restore_002c-compstate"></span></p>
<p><code>restore</code></p>
<p>This is set to <code>auto</code> before a function is entered, which forces the
special parameters mentioned above (<code>words</code>, <code>CURRENT</code>, <code>PREFIX</code>,
<code>IPREFIX</code>, <code>SUFFIX</code>, and <code>ISUFFIX</code>) to be restored to their previous
values when the function exits. If a function unsets it or sets it to
any other string, they will not be restored.</p>
<p><span id="index-to_005fend_002c-compstate"></span></p>
<p><code>to_end</code></p>
<p>Specifies the occasions on which the cursor is moved to the end of a
string when a match is inserted. On entry to a widget function, it may
be <code>single</code> if this will happen when a single unambiguous match was
inserted or <code>match</code> if it will happen any time a match is inserted (for
example, by menu completion; this is likely to be the effect of the
<code>ALWAYS_TO_END</code> option).</p>
<p>On exit, it may be set to <code>single</code> as above. It may also be set to
<code>always</code>, or to the empty string or unset; in those cases the cursor
will be moved to the end of the string always or never respectively. Any
other string is treated as <code>match</code>.</p>
<p><span id="index-unambiguous_002c-compstate"></span></p>
<p><code>unambiguous</code></p>
<p>This key is read-only and will always be set to the common (unambiguous)
prefix the completion code has generated for all matches added so far.</p>
<p><span id="index-unambiguous_005fcursor_002c-compstate"></span></p>
<p><code>unambiguous_cursor</code></p>
<p>This gives the position the cursor would be placed at if the common
prefix in the <code>unambiguous</code> key were inserted, relative to the value of
that key. The cursor would be placed before the character whose index is
given by this key.</p>
<p><span id="index-unambiguous_005fpositions_002c-compstate"></span></p>
<p><code>unambiguous_positions</code></p>
<p>This contains all positions where characters in the unambiguous string
are missing or where the character inserted differs from at least one of
the matches. The positions are given as indexes into the string given by
the value of the <code>unambiguous</code> key.</p>
<p><span id="index-vared_002c-compstate"></span></p>
<p><code>vared</code></p>
<p>If completion is called while editing a line using the <code>vared</code> builtin,
the value of this key is set to the name of the parameter given as an
argument to <code>vared</code>. This key is only set while a <code>vared</code> command is
active.</p>
<p><span id="index-words"></span></p>
<p><code>words</code></p>
<p>This array contains the words present on the command line currently
being edited.</p>
<hr />
<p><span id="Completion-Builtin-Commands"></span>
<span id="Completion-Builtin-Commands-1"></span></p>
<h2 id="193-completion-builtin-commands"><a class="header" href="#193-completion-builtin-commands">19.3 Completion Builtin Commands</a></h2>
<p><span id="index-compadd"></span>
<span id="index-completion-widgets_002c-adding-specified-matches"></span></p>
<p><code>compadd </code>[ <code>-akqQfenUl12C</code> ] [ <code>-F</code> <code>array</code> ]</p>
<p><code>        </code>[<code>-P</code> <code>prefix</code> ] [ <code>-S</code> <code>suffix</code> ]</p>
<p><code>        </code>[<code>-p</code> <code>hidden-prefix</code> ] [ <code>-s</code> <code>hidden-suffix</code> ]</p>
<p><code>        </code>[<code>-i</code> <code>ignored-prefix</code> ] [ <code>-I</code> <code>ignored-suffix</code> ]</p>
<p><code>        </code>[<code>-W</code> <code>file-prefix</code> ] [ <code>-d</code> <code>array</code> ]</p>
<p><code>        </code>[<code>-J</code> <code>group-name</code> ] [ <code>-X</code> <code>explanation</code> ] [ <code>-x</code>
<code>message</code> ]</p>
<p><code>        </code>[<code>-V</code> <code>group-name</code> ] [ <code>-o</code> [ <code>order</code> ] ]</p>
<p><code>        </code>[<code>-r</code> <code>remove-chars</code> ] [ <code>-R</code> <code>remove-func</code> ]</p>
<p><code>        </code>[<code>-D</code> <code>array</code> ] [ <code>-O</code> <code>array</code> ] [ <code>-A</code> <code>array</code> ]</p>
<p><code>        </code>[<code>-E</code> <code>number</code> ]</p>
<p><code>        </code>[<code>-M</code> <code>match-spec</code> ] [ <code>-``-</code> ] [ <code>words</code> ... ]</p>
<p>This builtin command can be used to add matches directly and control all
the information the completion code stores with each possible match. The
return status is zero if at least one match was added and non-zero if no
matches were added.</p>
<p>The completion code breaks the string to complete into seven fields in
the order:</p>
<blockquote>
<p><code>&lt;ipre&gt;&lt;apre&gt;&lt;hpre&gt;&lt;word&gt;&lt;hsuf&gt;&lt;asuf&gt;&lt;isuf&gt;</code></p>
</blockquote>
<p>The first field is an ignored prefix taken from the command line, the
contents of the <code>IPREFIX</code> parameter plus the string given with the <code>-i</code>
option. With the <code>-U</code> option, only the string from the <code>-i</code> option is
used. The field <code>&lt;apre&gt;</code> is an optional prefix string given with the
<code>-P</code> option. The <code>&lt;hpre&gt;</code> field is a string that is considered part of
the match but that should not be shown when listing completions, given
with the <code>-p</code> option; for example, functions that do filename generation
might specify a common path prefix this way. <code>&lt;word&gt;</code> is the part of the
match that should appear in the list of completions, i.e. one of the
<code>words</code> given at the end of the <code>compadd</code> command line. The suffixes
<code>&lt;hsuf&gt;</code>, <code>&lt;asuf&gt;</code> and <code>&lt;isuf&gt;</code> correspond to the prefixes <code>&lt;hpre&gt;</code>,
<code>&lt;apre&gt;</code> and <code>&lt;ipre&gt;</code> and are given by the options <code>-s</code>, <code>-S</code> and <code>-I</code>,
respectively.</p>
<p>The supported flags are:</p>
<ul>
<li>
<p><code>-P</code> <code>prefix</code><br />
This gives a string to be inserted before the given <code>words</code>. The
string given is not considered as part of the match and any shell
metacharacters in it will not be quoted when the string is inserted.</p>
</li>
<li>
<p><code>-S</code> <code>suffix</code><br />
Like <code>-P</code>, but gives a string to be inserted after the match.</p>
</li>
<li>
<p><code>-p</code> <code>hidden-prefix</code><br />
This gives a string that should be inserted into the command line
before the match but that should not appear in the list of matches.
Unless the <code>-U</code> option is given, this string must be matched as part
of the string on the command line.</p>
</li>
<li>
<p><code>-s</code> <code>hidden-suffix</code><br />
Like ‘<code>-p</code>’, but gives a string to insert after the match.</p>
</li>
<li>
<p><code>-i</code> <code>ignored-prefix</code><br />
This gives a string to insert into the command line just before any
string given with the ‘<code>-P</code>’ option. Without ‘<code>-P</code>’ the string is
inserted before the string given with ‘<code>-p</code>’ or directly before the
match.</p>
</li>
<li>
<p><code>-I</code> <code>ignored-suffix</code><br />
Like <code>-i</code>, but gives an ignored suffix.</p>
</li>
<li>
<p><code>-a</code><br />
With this flag the <code>words</code> are taken as names of arrays and the
possible matches are their values. If only some elements of the
arrays are needed, the <code>words</code> may also contain subscripts, as in
‘<code>foo[2,-1]</code>’.</p>
</li>
<li>
<p><code>-k</code><br />
With this flag the <code>words</code> are taken as names of associative arrays
and the possible matches are their keys. As for <code>-a</code>, the <code>words</code>
may also contain subscripts, as in ‘<code>foo[(R)*bar*]</code>’.</p>
</li>
<li>
<p><code>-d</code> <code>array</code><br />
This adds per-match display strings. The <code>array</code> should contain one
element per <code>word</code> given. The completion code will then display the
first element instead of the first <code>word</code>, and so on. The <code>array</code>
may be given as the name of an array parameter or directly as a
space-separated list of words in parentheses.</p>
<p>If there are fewer display strings than <code>words</code>, the leftover
<code>words</code> will be displayed unchanged and if there are more display
strings than <code>words</code>, the leftover display strings will be silently
ignored.</p>
</li>
<li>
<p><code>-l</code><br />
This option only has an effect if used together with the <code>-d</code>
option. If it is given, the display strings are listed one per line,
not arrayed in columns.</p>
</li>
<li>
<p><code>-o</code> [ <code>order</code> ]<br />
This controls the order in which matches are sorted. <code>order</code> is a
comma-separated list comprising the following possible values. These
values can be abbreviated to their initial two or three characters.
Note that the order forms part of the group name space so matches
with different orderings will not be in the same group.</p>
<ul>
<li>
<p><code>match</code><br />
If given, the order of the output is determined by the match
strings; otherwise it is determined by the display strings (i.e.
the strings given by the <code>-d</code> option). This is the default if
‘<code>-o</code>’ is specified but the <code>order</code> argument is omitted.</p>
</li>
<li>
<p><code>nosort</code><br />
This specifies that the matches are pre-sorted and their order
should be preserved. This value only makes sense alone and
cannot be combined with any others.</p>
</li>
<li>
<p><code>numeric</code><br />
If the matches include numbers, sort them numerically rather
than lexicographically.</p>
</li>
<li>
<p><code>reverse</code><br />
Arrange the matches backwards by reversing the sort ordering.</p>
</li>
</ul>
</li>
<li>
<p><code>-J</code> <code>group-name</code><br />
Gives the name of the group of matches the words should be stored
in.</p>
</li>
<li>
<p><code>-V</code> <code>group-name</code><br />
Like <code>-J</code> but naming an unsorted group. This option is identical to
the combination of <code>-J</code> and <code>-o nosort</code>.</p>
</li>
<li>
<p><code>-1</code><br />
If given together with the <code>-V</code> option, makes only consecutive
duplicates in the group be removed. If combined with the <code>-J</code>
option, this has no visible effect. Note that groups with and
without this flag are in different name spaces.</p>
</li>
<li>
<p><code>-2</code><br />
If given together with the <code>-J</code> or <code>-V</code> option, makes all duplicates
be kept. Again, groups with and without this flag are in different
name spaces.</p>
</li>
<li>
<p><code>-X</code> <code>explanation</code><br />
The <code>explanation</code> string will be printed with the list of matches,
above the group currently selected.</p>
<p>Within the <code>explanation</code>, the following sequences may be used to
specify output attributes (see <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>): ‘<code>%B</code>’, ‘<code>%S</code>’,
‘<code>%U</code>’, ‘<code>%F</code>’, ‘<code>%K</code>’ and their lower case counterparts, as well as
‘<code>%{</code>...<code>%}</code>’. ‘<code>%F</code>’, ‘<code>%K</code>’ and ‘<code>%{</code>...<code>%}</code>’ take arguments in
the same form as prompt expansion. (Note that the sequence ‘<code>%G</code>’ is
not available; an argument to ‘<code>%{</code>’ should be used instead.) The
sequence ‘<code>%%</code>’ produces a literal ‘<code>%</code>’.</p>
<p>These sequences are most often employed by users when customising
the <code>format</code> style (see <a href="Completion-System.html#Completion-System">Completion
System</a>), but they must
also be taken into account when writing completion functions, as
passing descriptions with unescaped ‘<code>%</code>’ characters to utility
functions such as <code>_arguments</code> and <code>_message</code> may produce unexpected
results. If arbitrary text is to be passed in a description, it can
be escaped using e.g. <code>${my_str//\%/%%}</code>.</p>
</li>
<li>
<p><code>-x</code> <code>message</code><br />
Like <code>-X</code>, but the <code>message</code> will be printed even if there are no
matches in the group.</p>
</li>
<li>
<p><code>-q</code><br />
The suffix given with <code>-S</code> will be automatically removed if the next
character typed is a blank or does not insert anything, or if the
suffix consists of only one character and the next character typed
is the same character.</p>
</li>
<li>
<p><code>-r</code> <code>remove-chars</code><br />
This is a more versatile form of the <code>-q</code> option. The suffix given
with <code>-S</code> or the slash automatically added after completing
directories will be automatically removed if the next character
typed inserts one of the characters given in the <code>remove-chars</code>.
This string is parsed as a characters class and understands the
backslash sequences used by the <code>print</code> command. For example, ‘<code>-r &quot;a-z\t&quot;</code>’ removes the suffix if the next character typed inserts a
lower case character or a TAB, and ‘<code>-r &quot;^0-9&quot;</code>’ removes the suffix
if the next character typed inserts anything but a digit. One extra
backslash sequence is understood in this string: ‘<code>\-</code>’ stands for
all characters that insert nothing. Thus ‘<code>-S &quot;=&quot; -q</code>’ is the same
as ‘<code>-S &quot;=&quot; -r &quot;= \t\n\-&quot;</code>’.</p>
<p>This option may also be used without the <code>-S</code> option; then any
automatically added space will be removed when one of the characters
in the list is typed.</p>
</li>
<li>
<p><code>-R</code> <code>remove-func</code><br />
This is another form of the <code>-r</code> option. When a suffix has been
inserted and the completion accepted, the function <code>remove-func</code>
will be called after the next character typed. It is passed the
length of the suffix as an argument and can use the special
parameters available in ordinary (non-completion) zle widgets (see
<a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh Line Editor</a>) to analyse
and modify the command line.</p>
</li>
<li>
<p><code>-f</code><br />
If this flag is given, all of the matches built from <code>words</code> are
marked as being the names of files. They are not required to be
actual filenames, but if they are, and the option <code>LIST_TYPES</code> is
set, the characters describing the types of the files in the
completion lists will be shown. This also forces a slash to be added
when the name of a directory is completed.</p>
</li>
<li>
<p><code>-e</code><br />
This flag can be used to tell the completion code that the matches
added are parameter names for a parameter expansion. This will make
the <code>AUTO_PARAM_SLASH</code> and <code>AUTO_PARAM_KEYS</code> options be used for the
matches.</p>
</li>
<li>
<p><code>-W</code> <code>file-prefix</code><br />
This string is a pathname that will be prepended to each of the
matches formed by the given <code>words</code> together with any prefix
specified by the <code>-p</code> option to form a complete filename for
testing. Hence it is only useful if combined with the <code>-f</code> flag, as
the tests will not otherwise be performed.</p>
</li>
<li>
<p><code>-F</code> <code>array</code><br />
Specifies an array containing patterns. Words matching one of these
patterns are ignored, i.e. not considered to be possible matches.</p>
<p>The <code>array</code> may be the name of an array parameter or a list of
literal patterns enclosed in parentheses and quoted, as in ‘<code>-F &quot;(*?.o *?.h)&quot;</code>’. If the name of an array is given, the elements of
the array are taken as the patterns.</p>
</li>
<li>
<p><code>-Q</code><br />
This flag instructs the completion code not to quote any
metacharacters in the words when inserting them into the command
line.</p>
</li>
<li>
<p><code>-M</code> <code>match-spec</code><br />
This gives local match specifications as described below in
<a href="Completion-Widgets.html#Completion-Matching-Control">Completion Matching Control</a>. This
option may be given more than once. In this case all <code>match-spec</code>s
given are concatenated with spaces between them to form the
specification string to use. Note that they will only be used if the
<code>-U</code> option is not given.</p>
</li>
<li>
<p><code>-n</code><br />
Specifies that the words added are to be used as possible matches,
but are not to appear in the completion listing.</p>
</li>
<li>
<p><code>-U</code><br />
If this flag is given, all words given will be accepted and no
matching will be done by the completion code. Normally this is used
in functions that do the matching themselves.</p>
</li>
<li>
<p><code>-O</code> <code>array</code><br />
If this option is given, the <code>words</code> are <em>not</em> added to the set of
possible completions. Instead, matching is done as usual and all of
the <code>words</code> given as arguments that match the string on the command
line will be stored in the array parameter whose name is given as
<code>array</code>.</p>
</li>
<li>
<p><code>-A</code> <code>array</code><br />
As the <code>-O</code> option, except that instead of those of the <code>words</code>
which match being stored in <code>array</code>, the strings generated
internally by the completion code are stored. For example, with a
matching specification of ‘<code>-M &quot;L:|no=&quot;</code>’, the string ‘<code>nof</code>’ on the
command line and the string ‘<code>foo</code>’ as one of the <code>words</code>, this
option stores the string ‘<code>nofoo</code>’ in the array, whereas the <code>-O</code>
option stores the ‘<code>foo</code>’ originally given.</p>
</li>
<li>
<p><code>-D</code> <code>array</code><br />
As with <code>-O</code>, the <code>words</code> are not added to the set of possible
completions. Instead, the completion code tests whether each <code>word</code>
in turn matches what is on the line. If the <code>n</code>th <code>word</code> does not
match, the <code>n</code>th element of the <code>array</code> is removed. Elements for
which the corresponding <code>word</code> is matched are retained.</p>
</li>
<li>
<p><code>-C</code><br />
This option adds a special match which expands to all other matches
when inserted into the line, even those that are added after this
option is used. Together with the <code>-d</code> option it is possible to
specify a string that should be displayed in the list for this
special match. If no string is given, it will be shown as a string
containing the strings that would be inserted for the other matches,
truncated to the width of the screen.</p>
</li>
<li>
<p><code>-E</code> <code>number</code><br />
This option adds <code>number</code> empty matches after the <code>words</code> have been
added. An empty match takes up space in completion listings but will
never be inserted in the line and can’t be selected with menu
completion or menu selection. This makes empty matches only useful
to format completion lists and to make explanatory string be shown
in completion lists (since empty matches can be given display
strings with the <code>-d</code> option). And because all but one empty string
would otherwise be removed, this option implies the <code>-V</code> and <code>-2</code>
options (even if an explicit <code>-J</code> option is given). This can be
important to note as it affects the name space into which matches
are added.</p>
</li>
<li>
<p><code>-</code><br />
<code>-``-</code><br />
This flag ends the list of flags and options. All arguments after it
will be taken as the words to use as matches even if they begin with
hyphens.</p>
</li>
</ul>
<p>Except for the <code>-M</code> flag, if any of these flags is given more than once,
the first one (and its argument) will be used.</p>
<p><span id="index-compset"></span>
<span id="index-completion-widgets_002c-modifying-special-parameters"></span></p>
<p><code>compset -p</code> <code>number</code></p>
<p><code>compset -P</code> [ <code>number</code> ] <code>pattern</code></p>
<p><code>compset -s</code> <code>number</code></p>
<p><code>compset -S</code> [ <code>number</code> ] <code>pattern</code></p>
<p><code>compset -n</code> <code>begin</code> [ <code>end</code> ]</p>
<p><code>compset -N</code> <code>beg-pat</code> [ <code>end-pat</code> ]</p>
<p><code>compset -q</code></p>
<p>This command simplifies modification of the special parameters, while
its return status allows tests on them to be carried out.</p>
<p>The options are:</p>
<ul>
<li>
<p><code>-p</code> <code>number</code><br />
If the value of the <code>PREFIX</code> parameter is at least <code>number</code>
characters long, the first <code>number</code> characters are removed from it
and appended to the contents of the <code>IPREFIX</code> parameter.</p>
</li>
<li>
<p><code>-P</code> [ <code>number</code> ] <code>pattern</code><br />
If the value of the <code>PREFIX</code> parameter begins with anything that
matches the <code>pattern</code>, the matched portion is removed from <code>PREFIX</code>
and appended to <code>IPREFIX</code>.</p>
<p>Without the optional <code>number</code>, the longest match is taken, but if
<code>number</code> is given, anything up to the <code>number</code>th match is moved. If
the <code>number</code> is negative, the <code>number</code>th longest match is moved. For
example, if <code>PREFIX</code> contains the string ‘<code>a=b=c</code>’, then <code>compset -P ’*=’</code> will move the string ‘<code>a=b=</code>’ into the <code>IPREFIX</code> parameter,
but <code>compset -P 1 ’*\=’</code> will move only the string ‘<code>a=</code>’.</p>
</li>
<li>
<p><code>-s</code> <code>number</code><br />
As <code>-p</code>, but transfer the last <code>number</code> characters from the value of
<code>SUFFIX</code> to the front of the value of <code>ISUFFIX</code>.</p>
</li>
<li>
<p><code>-S</code> [ <code>number</code> ] <code>pattern</code><br />
As <code>-P</code>, but match the last portion of <code>SUFFIX</code> and transfer the
matched portion to the front of the value of <code>ISUFFIX</code>.</p>
</li>
<li>
<p><code>-n</code> <code>begin</code> [ <code>end</code> ]<br />
If the current word position as specified by the parameter <code>CURRENT</code>
is greater than or equal to <code>begin</code>, anything up to the <code>begin</code>th
word is removed from the <code>words</code> array and the value of the
parameter <code>CURRENT</code> is decremented by <code>begin</code>.</p>
<p>If the optional <code>end</code> is given, the modification is done only if the
current word position is also less than or equal to <code>end</code>. In this
case, the words from position <code>end</code> onwards are also removed from
the <code>words</code> array.</p>
<p>Both <code>begin</code> and <code>end</code> may be negative to count backwards from the
last element of the <code>words</code> array.</p>
</li>
<li>
<p><code>-N</code> <code>beg-pat</code> [ <code>end-pat</code> ]<br />
If one of the elements of the <code>words</code> array before the one at the
index given by the value of the parameter <code>CURRENT</code> matches the
pattern <code>beg-pat</code>, all elements up to and including the matching one
are removed from the <code>words</code> array and the value of <code>CURRENT</code> is
changed to point to the same word in the changed array.</p>
<p>If the optional pattern <code>end-pat</code> is also given, and there is an
element in the <code>words</code> array matching this pattern, the parameters
are modified only if the index of this word is higher than the one
given by the <code>CURRENT</code> parameter (so that the matching word has to
be after the cursor). In this case, the words starting with the one
matching <code>end-pat</code> are also removed from the <code>words</code> array. If
<code>words</code> contains no word matching <code>end-pat</code>, the testing and
modification is performed as if it were not given.</p>
</li>
<li>
<p><code>-q</code><br />
The word currently being completed is split on spaces into separate
words, respecting the usual shell quoting conventions. The resulting
words are stored in the <code>words</code> array, and <code>CURRENT</code>, <code>PREFIX</code>,
<code>SUFFIX</code>, <code>QIPREFIX</code>, and <code>QISUFFIX</code> are modified to reflect the
word part that is completed.</p>
</li>
</ul>
<p>In all the above cases the return status is zero if the test succeeded
and the parameters were modified and non-zero otherwise. This allows one
to use this builtin in tests such as:</p>
<div class="example">
<pre><code class="language-example">if compset -P '*\='; then ...
</code></pre>
</div>
<p>This forces anything up to and including the last equal sign to be
ignored by the completion code.</p>
<p><code>compcall</code> [ <code>-TD</code> ]</p>
<p>This allows the use of completions defined with the <code>compctl</code> builtin
from within completion widgets. The list of matches will be generated as
if one of the non-widget completion functions (<code>complete-word</code>, etc.)
had been called, except that only <code>compctl</code>s given for specific commands
are used. To force the code to try completions defined with the <code>-T</code>
option of <code>compctl</code> and/or the default completion (whether defined by
<code>compctl -D</code> or the builtin default) in the appropriate places, the <code>-T</code>
and/or <code>-D</code> flags can be passed to <code>compcall</code>.</p>
<p>The return status can be used to test if a matching <code>compctl</code> definition
was found. It is non-zero if a <code>compctl</code> was found and zero otherwise.</p>
<p>Note that this builtin is defined by the <code>zsh/compctl</code> module.</p>
<hr />
<p><span id="Completion-Condition-Codes"></span>
<span id="Completion-Condition-Codes-1"></span></p>
<h2 id="194-completion-condition-codes"><a class="header" href="#194-completion-condition-codes">19.4 Completion Condition Codes</a></h2>
<p><span id="index-completion-widgets_002c-condition-codes"></span></p>
<p>The following additional condition codes for use within the <code>[[</code> <code>...</code>
<code>]]</code> construct are available in completion widgets. These work on the
special parameters. All of these tests can also be performed by the
<code>compset</code> builtin, but in the case of the condition codes the contents
of the special parameters are not modified.</p>
<ul>
<li>
<p><code>-prefix</code> [ <code>number</code> ] <code>pattern</code><br />
true if the test for the <code>-P</code> option of <code>compset</code> would succeed.</p>
</li>
<li>
<p><code>-suffix</code> [ <code>number</code> ] <code>pattern</code><br />
true if the test for the <code>-S</code> option of <code>compset</code> would succeed.</p>
</li>
<li>
<p><code>-after</code> <code>beg-pat</code><br />
true if the test of the <code>-N</code> option with only the <code>beg-pat</code> given
would succeed.</p>
</li>
<li>
<p><code>-between</code> <code>beg-pat end-pat</code><br />
true if the test for the <code>-N</code> option with both patterns would
succeed.</p>
</li>
</ul>
<hr />
<p><span id="Completion-Matching-Control"></span>
<span id="Completion-Matching-Control-1"></span></p>
<h2 id="195-completion-matching-control"><a class="header" href="#195-completion-matching-control">19.5 Completion Matching Control</a></h2>
<p>It is possible by use of the <code>-M</code> option of the <code>compadd</code> builtin
command to specify how the characters in the string to be completed
(referred to here as the command line) map onto the characters in the
list of matches produced by the completion code (referred to here as the
trial completions). Note that this is not used if the command line
contains a glob pattern and the <code>GLOB_COMPLETE</code> option is set or the
<code>pattern_match</code> of the <code>compstate</code> special association is set to a
non-empty string.</p>
<p>The <code>match-spec</code> given as the argument to the <code>-M</code> option (see
<a href="Completion-Widgets.html#Completion-Builtin-Commands">Completion Builtin Commands</a>) consists of
one or more matching descriptions separated by whitespace. Each
description consists of a letter followed by a colon and then the
patterns describing which character sequences on the line match which
character sequences in the trial completion. Any sequence of characters
not handled in this fashion must match exactly, as usual.</p>
<p>The forms of <code>match-spec</code> understood are as follows. In each case, the
form with an upper case initial character retains the string already
typed on the command line as the final result of completion, while with
a lower case initial character the string on the command line is changed
into the corresponding part of the trial completion.</p>
<ul>
<li>
<p><code>m:``lpat``=``tpat</code><br />
<code>M:``lpat``=``tpat</code><br />
Here, <code>lpat</code> is a pattern that matches on the command line,
corresponding to <code>tpat</code> which matches in the trial completion.</p>
</li>
<li>
<p><code>l:``lanchor``|``lpat``=``tpat</code><br />
<code>L:``lanchor``|``lpat``=``tpat</code><br />
<code>l:``lanchor``||``ranchor``=``tpat</code><br />
<code>L:``lanchor``||``ranchor``=``tpat</code><br />
<code>b:``lpat``=``tpat</code><br />
<code>B:``lpat``=``tpat</code><br />
These letters are for patterns that are anchored by another pattern
on the left side. Matching for <code>lpat</code> and <code>tpat</code> is as for <code>m</code> and
<code>M</code>, but the pattern <code>lpat</code> matched on the command line must be
preceded by the pattern <code>lanchor</code>. The <code>lanchor</code> can be blank to
anchor the match to the start of the command line string; otherwise
the anchor can occur anywhere, but must match in both the command
line and trial completion strings.</p>
<p>If no <code>lpat</code> is given but a <code>ranchor</code> is, this matches the gap
between substrings matched by <code>lanchor</code> and <code>ranchor</code>. Unlike
<code>lanchor</code>, the <code>ranchor</code> only needs to match the trial completion
string.</p>
<p>The <code>b</code> and <code>B</code> forms are similar to <code>l</code> and <code>L</code> with an empty
anchor, but need to match only the beginning of the word on the
command line or trial completion, respectively.</p>
</li>
<li>
<p><code>r:``lpat``|``ranchor``=``tpat</code><br />
<code>R:``lpat``|``ranchor``=``tpat</code><br />
<code>r:``lanchor``||``ranchor``=``tpat</code><br />
<code>R:``lanchor``||``ranchor``=``tpat</code><br />
<code>e:``lpat``=``tpat</code><br />
<code>E:``lpat``=``tpat</code><br />
As <code>l</code>, <code>L</code>, <code>b</code> and <code>B</code>, with the difference that the command line
and trial completion patterns are anchored on the right side. Here
an empty <code>ranchor</code> and the <code>e</code> and <code>E</code> forms force the match to the
end of the command line or trial completion string.</p>
</li>
<li>
<p><code>x:</code><br />
This form is used to mark the end of matching specifications:
subsequent specifications are ignored. In a single standalone list
of specifications this has no use but where matching specifications
are accumulated, such as from nested function calls, it can allow
one function to override another.</p>
</li>
</ul>
<p>Each <code>lpat</code>, <code>tpat</code> or <code>anchor</code> is either an empty string or consists of
a sequence of literal characters (which may be quoted with a backslash),
question marks, character classes, and correspondence classes; ordinary
shell patterns are not used. Literal characters match only themselves,
question marks match any character, and character classes are formed as
for globbing and match any character in the given set.</p>
<p>Correspondence classes are defined like character classes, but with two
differences: they are delimited by a pair of braces, and negated classes
are not allowed, so the characters <code>!</code> and <code>^</code> have no special meaning
directly after the opening brace. They indicate that a range of
characters on the line match a range of characters in the trial
completion, but (unlike ordinary character classes) paired according to
the corresponding position in the sequence. For example, to make any
ASCII lower case letter on the line match the corresponding upper case
letter in the trial completion, you can use ‘<code>m:{a-z}={A-Z}</code>’ (however,
see below for the recommended form for this). More than one pair of
classes can occur, in which case the first class before the <code>=</code>
corresponds to the first after it, and so on. If one side has more such
classes than the other side, the superfluous classes behave like normal
character classes. In anchor patterns correspondence classes also behave
like normal character classes.</p>
<p>The standard ‘<code>[:``name``:]</code>’ forms described for standard shell
patterns (see <a href="Expansion.html#Filename-Generation">Filename Generation</a>)
may appear in correspondence classes as well as normal character
classes. The only special behaviour in correspondence classes is if the
form on the left and the form on the right are each one of <code>[:upper:]</code>,
<code>[:lower:]</code>. In these cases the character in the word and the character
on the line must be the same up to a difference in case. Hence to make
any lower case character on the line match the corresponding upper case
character in the trial completion you can use
‘<code>m:{[:lower:]}={[:upper:]}</code>’. Although the matching system does not
yet handle multibyte characters, this is likely to be a future
extension, at which point this syntax will handle arbitrary alphabets;
hence this form, rather than the use of explicit ranges, is the
recommended form. In other cases ‘<code>[:``name``:]</code>’ forms are allowed. If
the two forms on the left and right are the same, the characters must
match exactly. In remaining cases, the corresponding tests are applied
to both characters, but they are not otherwise constrained; any matching
character in one set goes with any matching character in the other set:
this is equivalent to the behaviour of ordinary character classes.</p>
<p>The pattern <code>tpat</code> may also be one or two stars, ‘<code>*</code>’ or ‘<code>**</code>’. This
means that the pattern on the command line can match any number of
characters in the trial completion. In this case the pattern must be
anchored (on either side); in the case of a single star, the <code>anchor</code>
then determines how much of the trial completion is to be included —
only the characters up to the next appearance of the anchor will be
matched. With two stars, substrings matched by the anchor can be
matched, too.</p>
<p>Examples:</p>
<p>The keys of the <code>options</code> association defined by the <code>parameter</code> module
are the option names in all-lower-case form, without underscores, and
without the optional <code>no</code> at the beginning even though the builtins
<code>setopt</code> and <code>unsetopt</code> understand option names with upper case letters,
underscores, and the optional <code>no</code>. The following alters the matching
rules so that the prefix <code>no</code> and any underscore are ignored when trying
to match the trial completions generated and upper case letters on the
line match the corresponding lower case letters in the words:</p>
<div class="example">
<pre><code class="language-example">compadd -M 'L:|[nN][oO]= M:_= M:{[:upper:]}={[:lower:]}' - \
${(k)options}
</code></pre>
</div>
<p>The first part says that the pattern ‘<code>[nN][oO]</code>’ at the beginning (the
empty anchor before the pipe symbol) of the string on the line matches
the empty string in the list of words generated by completion, so it
will be ignored if present. The second part does the same for an
underscore anywhere in the command line string, and the third part uses
correspondence classes so that any upper case letter on the line matches
the corresponding lower case letter in the word. The use of the upper
case forms of the specification characters (<code>L</code> and <code>M</code>) guarantees that
what has already been typed on the command line (in particular the
prefix <code>no</code>) will not be deleted.</p>
<p>Note that the use of <code>L</code> in the first part means that it matches only
when at the beginning of both the command line string and the trial
completion. I.e., the string ‘<code>_NO_f</code>’ would not be completed to
‘<code>_NO_foo</code>’, nor would ‘<code>NONO_f</code>’ be completed to ‘<code>NONO_foo</code>’ because
of the leading underscore or the second ‘<code>NO</code>’ on the line which makes
the pattern fail even though they are otherwise ignored. To fix this,
one would use ‘<code>B:[nN][oO]=</code>’ instead of the first part. As described
above, this matches at the beginning of the trial completion,
independent of other characters or substrings at the beginning of the
command line word which are ignored by the same or other <code>match-spec</code>s.</p>
<p>The second example makes completion case insensitive. This is just the
same as in the option example, except here we wish to retain the
characters in the list of completions:</p>
<div class="example">
<pre><code class="language-example">compadd -M 'm:{[:lower:]}={[:upper:]}' ...
</code></pre>
</div>
<p>This makes lower case letters match their upper case counterparts. To
make upper case letters match the lower case forms as well:</p>
<div class="example">
<pre><code class="language-example">compadd -M 'm:{[:lower:][:upper:]}={[:upper:][:lower:]}' ...
</code></pre>
</div>
<p>A nice example for the use of <code>*</code> patterns is partial word completion.
Sometimes you would like to make strings like ‘<code>c.s.u</code>’ complete to
strings like ‘<code>comp.source.unix</code>’, i.e. the word on the command line
consists of multiple parts, separated by a dot in this example, where
each part should be completed separately — note, however, that the case
where each part of the word, i.e. ‘<code>comp</code>’, ‘<code>source</code>’ and ‘<code>unix</code>’ in
this example, is to be completed from separate sets of matches is a
different problem to be solved by the implementation of the completion
widget. The example can be handled by:</p>
<div class="example">
<pre><code class="language-example">compadd -M 'r:|.=* r:|=*' \
- comp.sources.unix comp.sources.misc ...
</code></pre>
</div>
<p>The first specification says that <code>lpat</code> is the empty string, while
<code>anchor</code> is a dot; <code>tpat</code> is <code>*</code>, so this can match anything except for
the ‘<code>.</code>’ from the anchor in the trial completion word. So in ‘<code>c.s.u</code>’,
the matcher sees ‘<code>c</code>’, followed by the empty string, followed by the
anchor ‘<code>.</code>’, and likewise for the second dot, and replaces the empty
strings before the anchors, giving
‘<code>c</code>[<code>omp</code>]<code>.s</code>[<code>ources</code>]<code>.u</code>[<code>nix</code>]’, where the last part of
the completion is just as normal.</p>
<p>With the pattern shown above, the string ‘<code>c.u</code>’ could not be completed
to ‘<code>comp.sources.unix</code>’ because the single star means that no dot
(matched by the anchor) can be skipped. By using two stars as in
‘<code>r:|.=**</code>’, however, ‘<code>c.u</code>’ could be completed to
‘<code>comp.sources.unix</code>’. This also shows that in some cases, especially
if the anchor is a real pattern, like a character class, the form with
two stars may result in more matches than one would like.</p>
<p>The second specification is needed to make this work when the cursor is
in the middle of the string on the command line and the option
<code>COMPLETE_IN_WORD</code> is set. In this case the completion code would
normally try to match trial completions that end with the string as
typed so far, i.e. it will only insert new characters at the cursor
position rather than at the end. However in our example we would like
the code to recognise matches which contain extra characters after the
string on the line (the ‘<code>nix</code>’ in the example). Hence we say that the
empty string at the end of the string on the line matches any characters
at the end of the trial completion.</p>
<p>More generally, the specification</p>
<div class="example">
<pre><code class="language-example">compadd -M 'r:|[.,_-]=* r:|=*' ...
</code></pre>
</div>
<p>allows one to complete words with abbreviations before any of the
characters in the square brackets. For example, to complete
<code>veryverylongfile.c</code> rather than <code>veryverylongheader.h</code> with the above
in effect, you can just type <code>very.c</code> before attempting completion.</p>
<p>The specifications with both a left and a right anchor are useful to
complete partial words whose parts are not separated by some special
character. For example, in some places strings have to be completed that
are formed ‘<code>LikeThis</code>’ (i.e. the separate parts are determined by a
leading upper case letter) or maybe one has to complete strings with
trailing numbers. Here one could use the simple form with only one
anchor as in:</p>
<div class="example">
<pre><code class="language-example">compadd -M 'r:|[[:upper:]0-9]=* r:|=*' LikeTHIS FooHoo 5foo123 5bar234
</code></pre>
</div>
<p>But with this, the string ‘<code>H</code>’ would neither complete to ‘<code>FooHoo</code>’ nor
to ‘<code>LikeTHIS</code>’ because in each case there is an upper case letter
before the ‘<code>H</code>’ and that is matched by the anchor. Likewise, a ‘<code>2</code>’
would not be completed. In both cases this could be changed by using
‘<code>r:|[[:upper:]0-9]=**</code>’, but then ‘<code>H</code>’ completes to both
‘<code>LikeTHIS</code>’ and ‘<code>FooHoo</code>’ and a ‘<code>2</code>’ matches the other strings
because characters can be inserted before every upper case letter and
digit. To avoid this one would use:</p>
<div class="example">
<pre><code class="language-example">compadd -M 'r:[^[:upper:]0-9]||[[:upper:]0-9]=** r:|=*' \
LikeTHIS FooHoo foo123 bar234
</code></pre>
</div>
<p>By using these two anchors, a ‘<code>H</code>’ matches only upper case ‘<code>H</code>’s that
are immediately preceded by something matching the left anchor
‘<code>[^[:upper:]0-9]</code>’. The effect is, of course, that ‘<code>H</code>’ matches only
the string ‘<code>FooHoo</code>’, a ‘<code>2</code>’ matches only ‘<code>bar234</code>’ and so on.</p>
<p>When using the completion system (see <a href="Completion-System.html#Completion-System">Completion
System</a>), users can define
match specifications that are to be used for specific contexts by using
the <code>matcher</code> and <code>matcher-list</code> styles. The values for the latter will
be used everywhere.</p>
<hr />
<p><span id="Completion-Widget-Example"></span>
<span id="Completion-Widget-Example-1"></span></p>
<h2 id="196-completion-widget-example"><a class="header" href="#196-completion-widget-example">19.6 Completion Widget Example</a></h2>
<p><span id="index-completion-widgets_002c-example"></span></p>
<p>The first step is to define the widget:</p>
<div class="example">
<pre><code class="language-example">zle -C complete complete-word complete-files
</code></pre>
</div>
<p>Then the widget can be bound to a key using the <code>bindkey</code> builtin
command:</p>
<div class="example">
<pre><code class="language-example">bindkey '^X\t' complete
</code></pre>
</div>
<p>After that the shell function <code>complete-files</code> will be invoked after
typing control-X and TAB. The function should then generate the matches,
e.g.:</p>
<div class="example">
<pre><code class="language-example">complete-files () { compadd - * }
</code></pre>
</div>
<p>This function will complete files in the current directory matching the
current word.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Completion-System.html#20-completion-system">20 Completion System</a>
<ul>
<li><a href="Completion-System.html#201-description">20.1 Description</a></li>
<li><a href="Completion-System.html#202-initialization">20.2 Initialization</a>
<ul>
<li><a href="Completion-System.html#2021-use-of-compinit">20.2.1 Use of compinit</a></li>
<li><a href="Completion-System.html#2022-autoloaded-files">20.2.2 Autoloaded files</a></li>
<li><a href="Completion-System.html#2023-functions">20.2.3 Functions</a></li>
</ul>
</li>
<li><a href="Completion-System.html#203-completion-system-configuration">20.3 Completion System Configuration</a>
<ul>
<li><a href="Completion-System.html#2031-overview">20.3.1 Overview</a></li>
<li><a href="Completion-System.html#2032-standard-tags">20.3.2 Standard Tags</a></li>
<li><a href="Completion-System.html#2033-standard-styles">20.3.3 Standard Styles</a></li>
</ul>
</li>
<li><a href="Completion-System.html#204-control-functions">20.4 Control Functions</a></li>
<li><a href="Completion-System.html#205-bindable-commands">20.5 Bindable Commands</a></li>
<li><a href="Completion-System.html#206-utility-functions">20.6 Utility Functions</a></li>
<li><a href="Completion-System.html#207-completion-system-variables">20.7 Completion System Variables</a></li>
<li><a href="Completion-System.html#208-completion-directories">20.8 Completion Directories</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Completion-System"></span>
<span id="Completion-System-1"></span></p>
<h1 id="20-completion-system"><a class="header" href="#20-completion-system">20 Completion System</a></h1>
<p><span id="index-completion-system"></span>
<span id="index-completion_002c-programmable-1"></span>
<span id="index-completion_002c-controlling-1"></span></p>
<hr />
<p><span id="Description-3"></span></p>
<h2 id="201-description"><a class="header" href="#201-description">20.1 Description</a></h2>
<p>This describes the shell code for the ‘new’ completion system, referred
to as <code>compsys</code>. It is written in shell functions based on the features
described in the previous chapter, <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a>.</p>
<p>The features are contextual, sensitive to the point at which completion
is started. Many completions are already provided. For this reason, a
user can perform a great many tasks without knowing any details beyond
how to initialize the system, which is described in
<a href="Completion-System.html#Initialization">Initialization</a>.</p>
<p>The context that decides what completion is to be performed may be</p>
<ul>
<li>an argument or option position: these describe the position on the
command line at which completion is requested. For example ‘first
argument to rmdir, the word being completed names a directory’;</li>
<li>a special context, denoting an element in the shell’s syntax. For
example ‘a word in command position’ or ‘an array subscript’.</li>
</ul>
<p>A full context specification contains other elements, as we shall
describe.</p>
<p>Besides commands names and contexts, the system employs two more
concepts, <em>styles</em> and <em>tags</em>. These provide ways for the user to
configure the system’s behaviour.</p>
<p>Tags play a dual role. They serve as a classification system for the
matches, typically indicating a class of object that the user may need
to distinguish. For example, when completing arguments of the <code>ls</code>
command the user may prefer to try <code>files</code> before <code>directories</code>, so both
of these are tags. They also appear as the rightmost element in a
context specification.</p>
<p>Styles modify various operations of the completion system, such as
output formatting, but also what kinds of completers are used (and in
what order), or which tags are examined. Styles may accept arguments and
are manipulated using the <code>zstyle</code> command described in <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a>.</p>
<p>In summary, tags describe <em>what</em> the completion objects are, and style
<code>how</code> they are to be completed. At various points of execution, the
completion system checks what styles and/or tags are defined for the
current context, and uses that to modify its behavior. The full
description of context handling, which determines how tags and other
elements of the context influence the behaviour of styles, is described
in <a href="Completion-System.html#Completion-System-Configuration">Completion System Configuration</a>.</p>
<p>When a completion is requested, a dispatcher function is called; see the
description of <code>_main_complete</code> in the list of control functions below.
This dispatcher decides which function should be called to produce the
completions, and calls it. The result is passed to one or more
<em>completers</em>, functions that implement individual completion strategies:
simple completion, error correction, completion with error correction,
menu selection, etc.</p>
<p>More generally, the shell functions contained in the completion system
are of two types:</p>
<ul>
<li>those beginning ‘<code>comp</code>’ are to be called directly; there are only a
few of these;</li>
<li>those beginning ‘<code>_</code>’ are called by the completion code. The shell
functions of this set, which implement completion behaviour and may
be bound to keystrokes, are referred to as ‘widgets’. These
proliferate as new completions are required.</li>
</ul>
<hr />
<p><span id="Initialization"></span> <span id="Initialization-1"></span></p>
<h2 id="202-initialization"><a class="header" href="#202-initialization">20.2 Initialization</a></h2>
<p><span id="index-compinstall"></span>
<span id="index-completion-system_002c-installing"></span></p>
<p>If the system was installed completely, it should be enough to call the
shell function <code>compinit</code> from your initialization file; see the next
section. However, the function <code>compinstall</code> can be run by a user to
configure various aspects of the completion system.</p>
<p>Usually, <code>compinstall</code> will insert code into <code>.zshrc</code>, although if
file’s location. Note that it is up to you to make sure that the lines
added to <code>.zshrc</code> are actually run; you may, for example, need to move
them to an earlier place in the file if <code>.zshrc</code> usually returns early.
So long as you keep them all together (including the comment lines at
the start and finish), you can rerun <code>compinstall</code> and it will correctly
locate and modify these lines. Note, however, that any code you add to
this section by hand is likely to be lost if you rerun <code>compinstall</code>,
although lines using the command ‘<code>zstyle</code>’ should be gracefully
handled.</p>
<p>The new code will take effect next time you start the shell, or run
<code>.zshrc</code> by hand; there is also an option to make them take effect
immediately. However, if <code>compinstall</code> has removed definitions, you will
need to restart the shell to see the changes.</p>
<p>To run <code>compinstall</code> you will need to make sure it is in a directory
mentioned in your <code>fpath</code> parameter, which should already be the case if
zsh was properly configured as long as your startup files do not remove
the appropriate directories from <code>fpath</code>. Then it must be autoloaded
(‘<code>autoload -U compinstall</code>’ is recommended). You can abort the
installation any time you are being prompted for information, and your
<code>.zshrc</code> will not be altered at all; changes only take place right at
the end, where you are specifically asked for confirmation.</p>
<hr />
<p><span id="Use-of-compinit"></span></p>
<h3 id="2021-use-of-compinit"><a class="header" href="#2021-use-of-compinit">20.2.1 Use of compinit</a></h3>
<p><span id="index-compinit"></span>
<span id="index-completion-system_002c-initializing"></span></p>
<p>This section describes the use of <code>compinit</code> to initialize completion
for the current session when called directly; if you have run
<code>compinstall</code> it will be called automatically from your <code>.zshrc</code>.</p>
<p>To initialize the system, the function <code>compinit</code> should be in a
directory mentioned in the <code>fpath</code> parameter, and should be autoloaded
(‘<code>autoload -U compinit</code>’ is recommended), and then run simply as
‘<code>compinit</code>’. This will define a few utility functions, arrange for
all the necessary shell functions to be autoloaded, and will then
re-define all widgets that do completion to use the new system. If you
use the <code>menu-select</code> widget, which is part of the <code>zsh/complist</code>
module, you should make sure that that module is loaded before the call
to <code>compinit</code> so that that widget is also re-defined. If completion
styles (see below) are set up to perform expansion as well as completion
by default, and the TAB key is bound to <code>expand-or-complete</code>, <code>compinit</code>
will rebind it to <code>complete-word</code>; this is necessary to use the correct
form of expansion.</p>
<p>Should you need to use the original completion commands, you can still
bind keys to the old widgets by putting a ‘<code>.</code>’ in front of the widget
name, e.g. ‘<code>.expand-or-complete</code>’.</p>
<p>To speed up the running of <code>compinit</code>, it can be made to produce a
dumped configuration that will be read in on future invocations; this is
the default, but can be turned off by calling <code>compinit</code> with the option
<code>-D</code>. The dumped file is <code>.zcompdump</code> in the same directory as the
startup files (i.e. <code>$ZDOTDIR</code> or <code>$HOME</code>); alternatively, an explicit
file name can be given by ‘<code>compinit -d</code> <code>dumpfile</code>’. The next
invocation of <code>compinit</code> will read the dumped file instead of performing
a full initialization.</p>
<p>If the number of completion files changes, <code>compinit</code> will recognise
this and produce a new dump file. However, if the name of a function or
the arguments in the first line of a <code>#compdef</code> function (as described
below) change, it is easiest to delete the dump file by hand so that
<code>compinit</code> will re-create it the next time it is run. The check
performed to see if there are new functions can be omitted by giving the
option <code>-C</code>. In this case the dump file will only be created if there
isn’t one already.</p>
<p>The dumping is actually done by another function, <code>compdump</code>, but you
will only need to run this yourself if you change the configuration
(e.g. using <code>compdef</code>) and then want to dump the new one. The name of
the old dumped file will be remembered for this purpose.</p>
<p>If the parameter <code>_compdir</code> is set, <code>compinit</code> uses it as a directory
where completion functions can be found; this is only necessary if they
are not already in the function search path.</p>
<p>For security reasons <code>compinit</code> also checks if the completion system
would use files not owned by root or by the current user, or files in
root or by the current user. If such files or directories are found,
<code>compinit</code> will ask if the completion system should really be used. To
avoid these tests and make all files found be used without asking, use
the option <code>-u</code>, and to make <code>compinit</code> silently ignore all insecure
files and directories use the option <code>-i</code>. This security check is
skipped entirely when the <code>-C</code> option is given.</p>
<p><span id="index-compaudit"></span></p>
<p>The security check can be retried at any time by running the function
<code>compaudit</code>. This is the same check used by <code>compinit</code>, but when it is
executed directly any changes to <code>fpath</code> are made local to the function
so they do not persist. The directories to be checked may be passed as
arguments; if none are given, <code>compaudit</code> uses <code>fpath</code> and <code>_compdir</code> to
find completion system directories, adding missing ones to <code>fpath</code> as
necessary. To force a check of exactly the directories currently named
in <code>fpath</code>, set <code>_compdir</code> to an empty string before calling <code>compaudit</code>
or <code>compinit</code>.</p>
<p><span id="index-bashcompinit"></span></p>
<p>The function <code>bashcompinit</code> provides compatibility with bash’s
programmable completion system. When run it will define the functions,
<code>compgen</code> and <code>complete</code> which correspond to the bash builtins with the
same names. It will then be possible to use completion specifications
and functions written for bash.</p>
<hr />
<p><span id="Autoloaded-files"></span></p>
<h3 id="2022-autoloaded-files"><a class="header" href="#2022-autoloaded-files">20.2.2 Autoloaded files</a></h3>
<p><span id="index-completion-system_002c-autoloaded-functions"></span></p>
<p>The convention for autoloaded functions used in completion is that they
start with an underscore; as already mentioned, the <code>fpath/FPATH</code>
parameter must contain the directory in which they are stored. If <code>zsh</code>
was properly installed on your system, then <code>fpath/FPATH</code> automatically
contains the required directories for the standard functions.</p>
<p>For incomplete installations, if <code>compinit</code> does not find enough files
beginning with an underscore (fewer than twenty) in the search path, it
will try to find more by adding the directory <code>_compdir</code> to the search
path. If that directory has a subdirectory named <code>Base</code>, all
subdirectories will be added to the path. Furthermore, if the
subdirectory <code>Base</code> has a subdirectory named <code>Core</code>, <code>compinit</code> will add
all subdirectories of the subdirectories to the path: this allows the
functions to be in the same format as in the <code>zsh</code> source distribution.</p>
<p><span id="index-compdef_002c-use-of-by-compinit"></span></p>
<p>When <code>compinit</code> is run, it searches all such files accessible via
<code>fpath/FPATH</code> and reads the first line of each of them. This line should
contain one of the tags described below. Files whose first line does not
start with one of these tags are not considered to be part of the
completion system and will not be treated specially.</p>
<p>The tags are:</p>
<ul>
<li>
<p><code>#compdef</code> <code>name</code> ... [ <code>-</code>{<code>p</code>|<code>P</code>} <code>pattern</code> ... [ <code>-N</code> <code>name</code>
... ] ]<br />
The file will be made autoloadable and the function defined in it
will be called when completing <code>name</code>s, each of which is either the
name of a command whose arguments are to be completed or one of a
number of special contexts in the form <code>-``context``-</code> described
below.</p>
<p>Each <code>name</code> may also be of the form ‘<code>cmd``=``service</code>’. When
completing the command <code>cmd</code>, the function typically behaves as if
the command (or special context) <code>service</code> was being completed
instead. This provides a way of altering the behaviour of functions
that can perform many different completions. It is implemented by
setting the parameter <code>$service</code> when calling the function; the
function may choose to interpret this how it wishes, and simpler
functions will probably ignore it.</p>
<p>If the <code>#compdef</code> line contains one of the options <code>-p</code> or <code>-P</code>, the
words following are taken to be patterns. The function will be
called when completion is attempted for a command or context that
matches one of the patterns. The options <code>-p</code> and <code>-P</code> are used to
specify patterns to be tried before or after other completions
respectively. Hence <code>-P</code> may be used to specify default actions.</p>
<p>The option <code>-N</code> is used after a list following <code>-p</code> or <code>-P</code>; it
specifies that remaining words no longer define patterns. It is
possible to toggle between the three options as many times as
necessary.</p>
</li>
<li>
<p><code>#compdef -k</code> <code>style key-sequence</code> ...<br />
This option creates a widget behaving like the builtin widget
<code>style</code> and binds it to the given <code>key-sequence</code>s, if any. The
<code>style</code> must be one of the builtin widgets that perform completion,
namely <code>complete-word</code>, <code>delete-char-or-list</code>, <code>expand-or-complete</code>,
<code>expand-or-complete-prefix</code>, <code>list-choices</code>, <code>menu-complete</code>,
<code>menu-expand-or-complete</code>, or <code>reverse-menu-complete</code>. If the
<code>zsh/complist</code> module is loaded (see <a href="Zsh-Modules.html#The-zsh_002fcomplist-Module">The zsh/complist
Module</a>) the widget
<code>menu-select</code> is also available.</p>
<p>When one of the <code>key-sequence</code>s is typed, the function in the file
will be invoked to generate the matches. Note that a key will not be
re-bound if it already was (that is, was bound to something other
than <code>undefined-key</code>). The widget created has the same name as the
file and can be bound to any other keys using <code>bindkey</code> as usual.</p>
</li>
<li>
<p><code>#compdef -K</code> <code>widget-name</code> <code>style</code> <code>key-sequence</code> [ <code>name</code> <code>style</code>
<code>seq</code> ... ]<br />
This is similar to <code>-k</code> except that only one <code>key-sequence</code> argument
may be given for each <code>widget-name</code> <code>style</code> pair. However, the
entire set of three arguments may be repeated with a different set
of arguments. Note in particular that the <code>widget-name</code> must be
distinct in each set. If it does not begin with ‘<code>_</code>’ this will be
added. The <code>widget-name</code> should not clash with the name of any
existing widget: names based on the name of the function are most
useful. For example,</p>
<div class="example">
<pre><code class="language-example">#compdef -K _foo_complete complete-word &quot;^X^C&quot; \
_foo_list list-choices &quot;^X^D&quot;
</code></pre>
</div>
<p>(all on one line) defines a widget <code>_foo_complete</code> for completion,
bound to ‘<code>^X^C</code>’, and a widget <code>_foo_list</code> for listing, bound to
‘<code>^X^D</code>’.</p>
</li>
<li>
<p><code>#autoload</code> [ <code>options</code> ]<br />
Functions with the <code>#autoload</code> tag are marked for autoloading but
are not otherwise treated specially. Typically they are to be called
from within one of the completion functions. Any <code>options</code> supplied
will be passed to the <code>autoload</code> builtin; a typical use is <code>+X</code> to
force the function to be loaded immediately. Note that the <code>-U</code> and
<code>-z</code> flags are always added implicitly.</p>
</li>
</ul>
<p>The <code>#</code> is part of the tag name and no white space is allowed after it.
The <code>#compdef</code> tags use the <code>compdef</code> function described below; the main
difference is that the name of the function is supplied implicitly.</p>
<p>The special contexts for which completion functions can be defined are:</p>
<p><span id="index-_002darray_002dvalue_002d_002c-completion-context"></span></p>
<p><code>-array-value-</code></p>
<p>The right hand side of an array-assignment (‘<code>name``=(``...``)</code>’)</p>
<p><span id="index-_002dbrace_002dparameter_002d_002c-completion-context"></span></p>
<p><code>-brace-parameter-</code></p>
<p>The name of a parameter expansion within braces (‘<code>${``...``}</code>’)</p>
<p><span id="index-_002dassign_002dparameter_002d_002c-completion-context"></span></p>
<p><code>-assign-parameter-</code></p>
<p>The name of a parameter in an assignment, i.e. on the left hand side of
an ‘<code>=</code>’</p>
<p><span id="index-_002dcommand_002d_002c-completion-context"></span></p>
<p><code>-command-</code></p>
<p>A word in command position</p>
<p><span id="index-_002dcondition_002d_002c-completion-context"></span></p>
<p><code>-condition-</code></p>
<p>A word inside a condition (‘<code>[[``...``]]</code>’)</p>
<p><span id="index-_002ddefault_002d_002c-completion-context"></span></p>
<p><code>-default-</code></p>
<p>Any word for which no other completion is defined</p>
<p><span id="index-_002dequal_002d_002c-completion-context"></span></p>
<p><code>-equal-</code></p>
<p>A word beginning with an equals sign</p>
<p><span id="index-_002dfirst_002d_002c-completion-context"></span></p>
<p><code>-first-</code></p>
<p>This is tried before any other completion function. The function called
may set the <code>_compskip</code> parameter to one of various values: <code>all</code>: no
further completion is attempted; a string containing the substring
<code>patterns</code>: no pattern completion functions will be called; a string
containing <code>default</code>: the function for the ‘<code>-default-</code>’ context will
not be called, but functions defined for commands will be.</p>
<p><span id="index-_002dmath_002d_002c-completion-context"></span></p>
<p><code>-math-</code></p>
<p>Inside mathematical contexts, such as ‘<code>((``...``))</code>’</p>
<p><span id="index-_002dparameter_002d_002c-completion-context"></span></p>
<p><code>-parameter-</code></p>
<p>The name of a parameter expansion (‘<code>$``...</code>’)</p>
<p><span id="index-_002dredirect_002d_002c-completion-context"></span></p>
<p><code>-redirect-</code></p>
<p>The word after a redirection operator.</p>
<p><span id="index-_002dsubscript_002d_002c-completion-context"></span></p>
<p><code>-subscript-</code></p>
<p>The contents of a parameter subscript.</p>
<p><span id="index-_002dtilde_002d_002c-completion-context"></span></p>
<p><code>-tilde-</code></p>
<p>After an initial tilde (‘<code>~</code>’), but before the first slash in the word.</p>
<p><span id="index-_002dvalue_002d_002c-completion-context"></span></p>
<p><code>-value-</code></p>
<p>On the right hand side of an assignment.</p>
<p>Default implementations are supplied for each of these contexts. In most
cases the context <code>-``context``-</code> is implemented by a corresponding
function <code>_``context</code>, for example the context ‘<code>-tilde-</code>’ and the
function ‘<code>_tilde</code>’).</p>
<p>The contexts <code>-redirect-</code> and <code>-value-</code> allow extra context-specific
information. (Internally, this is handled by the functions for each
context calling the function <code>_dispatch</code>.) The extra information is
added separated by commas.</p>
<p>For the <code>-redirect-</code> context, the extra information is in the form
‘<code>-redirect-,``op``,``command</code>’, where <code>op</code> is the redirection
operator and <code>command</code> is the name of the command on the line. If there
is no command on the line yet, the <code>command</code> field will be empty.</p>
<p>For the <code>-value-</code> context, the form is ‘<code>-value-,``name``,``command</code>’,
where <code>name</code> is the name of the parameter on the left hand side of the
assignment. In the case of elements of an associative array, for example
‘<code>assoc=(key &lt;TAB&gt;</code>’, <code>name</code> is expanded to ‘<code>name``-``key</code>’. In certain
special contexts, such as completing after ‘<code>make CFLAGS=</code>’, the
<code>command</code> part gives the name of the command, here <code>make</code>; otherwise it
is empty.</p>
<p>It is not necessary to define fully specific completions as the
functions provided will try to generate completions by progressively
replacing the elements with ‘<code>-default-</code>’. For example, when completing
after ‘<code>foo=&lt;TAB&gt;</code>’, <code>_value</code> will try the names ‘<code>-value-,foo,</code>’ (note
the empty <code>command</code> part), ‘<code>-value-,foo,-default-</code>’
and‘<code>-value-,-default-,-default-</code>’, in that order, until it finds a
function to handle the context.</p>
<p>As an example:</p>
<div class="example">
<pre><code class="language-example">compdef '_files -g &quot;*.log&quot;' '-redirect-,2&gt;,-default-'
</code></pre>
</div>
<p>completes files matching ‘<code>*.log</code>’ after ‘<code>2&gt; &lt;TAB&gt;</code>’ for any command
with no more specific handler defined.</p>
<p>Also:</p>
<div class="example">
<pre><code class="language-example">compdef _foo -value-,-default-,-default-
</code></pre>
</div>
<p>specifies that <code>_foo</code> provides completions for the values of parameters
for which no special function has been defined. This is usually handled
by the function <code>_value</code> itself.</p>
<p>The same lookup rules are used when looking up styles (as described
below); for example</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:-redirect-,2&gt;,*:*' file-patterns '*.log'
</code></pre>
</div>
<p>is another way to make completion after ‘<code>2&gt; &lt;TAB&gt;</code>’ complete files
matching ‘<code>*.log</code>’.</p>
<hr />
<p><span id="Functions-4"></span></p>
<h3 id="2023-functions"><a class="header" href="#2023-functions">20.2.3 Functions</a></h3>
<p>The following function is defined by <code>compinit</code> and may be called
directly.</p>
<p><span id="index-compdef"></span>
<span id="index-completion-system_002c-adding-definitions"></span></p>
<ul>
<li>
<p><code>compdef</code> [ <code>-ane</code> ] <code>function name</code> ... [ <code>-</code>{<code>p</code>|<code>P</code>} <code>pattern</code>
... [ <code>-N</code> <code>name</code> ...]]<br />
<code>compdef -d</code> <code>name</code> ...<br />
<code>compdef -k</code> [ <code>-an</code> ] <code>function style key-sequence</code> [
<code>key-sequence</code> ... ]<br />
<code>compdef -K</code> [ <code>-an</code> ] <code>function name style key-seq</code> [ <code>name style seq</code> ... ]<br />
The first form defines the <code>function</code> to call for completion in the
given contexts as described for the <code>#compdef</code> tag above.</p>
<p>Alternatively, all the arguments may have the form
‘<code>cmd``=``service</code>’. Here <code>service</code> should already have been
defined by ‘<code>cmd1``=``service</code>’ lines in <code>#compdef</code> files, as
described above. The argument for <code>cmd</code> will be completed in the
same way as <code>service</code>.</p>
<p>The <code>function</code> argument may alternatively be a string containing
almost any shell code. If the string contains an equal sign, the
above will take precedence. The option <code>-e</code> may be used to specify
the first argument is to be evaluated as shell code even if it
contains an equal sign. The string will be executed using the <code>eval</code>
builtin command to generate completions. This provides a way of
avoiding having to define a new completion function. For example, to
complete files ending in ‘<code>.h</code>’ as arguments to the command <code>foo</code>:</p>
<div class="example">
<pre><code class="language-example">compdef '_files -g &quot;*.h&quot;' foo
</code></pre>
</div>
<p>The option <code>-n</code> prevents any completions already defined for the
command or context from being overwritten.</p>
<p>The option <code>-d</code> deletes any completion defined for the command or
contexts listed.</p>
<p>The <code>name</code>s may also contain <code>-p</code>, <code>-P</code> and <code>-N</code> options as
described for the <code>#compdef</code> tag. The effect on the argument list is
identical, switching between definitions of patterns tried
initially, patterns tried finally, and normal commands and contexts.</p>
<p>The parameter <code>$_compskip</code> may be set by any function defined for a
pattern context. If it is set to a value containing the substring
‘<code>patterns</code>’ none of the pattern-functions will be called; if it
is set to a value containing the substring ‘<code>all</code>’, no other
function will be called. Setting <code>$_compskip</code> in this manner is of
particular utility when using the <code>-p</code> option, as otherwise the
dispatcher will move on to additional functions (likely the default
one) after calling the pattern-context one, which can mangle the
display of completion possibilities if not handled properly.</p>
<p>The form with <code>-k</code> defines a widget with the same name as the
<code>function</code> that will be called for each of the <code>key-sequence</code>s; this
is like the <code>#compdef -k</code> tag. The function should generate the
completions needed and will otherwise behave like the builtin widget
whose name is given as the <code>style</code> argument. The widgets usable for
this are: <code>complete-word</code>, <code>delete-char-or-list</code>,
<code>expand-or-complete</code>, <code>expand-or-complete-prefix</code>, <code>list-choices</code>,
<code>menu-complete</code>, <code>menu-expand-or-complete</code>, and
<code>reverse-menu-complete</code>, as well as <code>menu-select</code> if the
<code>zsh/complist</code> module is loaded. The option <code>-n</code> prevents the key
being bound if it is already to bound to something other than
<code>undefined-key</code>.</p>
<p>The form with <code>-K</code> is similar and defines multiple widgets based on
the same <code>function</code>, each of which requires the set of three
arguments <code>name</code>, <code>style</code> and <code>key-seq</code>uence, where the latter two
are as for <code>-k</code> and the first must be a unique widget name beginning
with an underscore.</p>
<p>Wherever applicable, the <code>-a</code> option makes the <code>function</code>
autoloadable, equivalent to <code> autoload -U ``function</code>.</p>
</li>
</ul>
<p>The function <code>compdef</code> can be used to associate existing completion
functions with new commands. For example,</p>
<div class="example">
<pre><code class="language-example">compdef _pids foo
</code></pre>
</div>
<p>uses the function <code>_pids</code> to complete process IDs for the command <code>foo</code>.</p>
<p>Note also the <code>_gnu_generic</code> function described below, which can be used
to complete options for commands that understand the ‘<code>-``-help</code>’
option.</p>
<hr />
<p><span id="Completion-System-Configuration"></span>
<span id="Completion-System-Configuration-1"></span></p>
<h2 id="203-completion-system-configuration"><a class="header" href="#203-completion-system-configuration">20.3 Completion System Configuration</a></h2>
<p><span id="index-completion-system_002c-configuration"></span></p>
<p>This section gives a short overview of how the completion system works,
and then more detail on how users can configure how and when matches are
generated.</p>
<hr />
<p><span id="Overview-1"></span></p>
<h3 id="2031-overview"><a class="header" href="#2031-overview">20.3.1 Overview</a></h3>
<p>When completion is attempted somewhere on the command line the
completion system begins building the context. The context represents
everything that the shell knows about the meaning of the command line
and the significance of the cursor position. This takes account of a
number of things including the command word (such as ‘<code>grep</code>’ or
‘<code>zsh</code>’) and options to which the current word may be an argument
(such as the ‘<code>-o</code>’ option to <code>zsh</code> which takes a shell option as an
argument).</p>
<p>The context starts out very generic (&quot;we are beginning a completion&quot;)
and becomes more specific as more is learned (&quot;the current word is in a
position that is usually a command name&quot; or &quot;the current word might be a
variable name&quot; and so on). Therefore the context will vary during the
same call to the completion system.</p>
<p>This context information is condensed into a string consisting of
multiple fields separated by colons, referred to simply as ‘the context’
in the remainder of the documentation. Note that a user of the
completion system rarely needs to compose a context string, unless for
example a new function is being written to perform completion for a new
command. What a user may need to do is compose a <em>style</em> pattern, which
is matched against a context when needed to look up context-sensitive
options that configure the completion system.</p>
<p>The next few paragraphs explain how a context is composed within the
completion function suite. Following that is discussion of how <em>styles</em>
are defined. Styles determine such things as how the matches are
generated, similarly to shell options but with much more control. They
are defined with the <code>zstyle</code> builtin command (<a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a>).</p>
<p>The context string always consists of a fixed set of fields, separated
by colons and with a leading colon before the first. Fields which are
not yet known are left empty, but the surrounding colons appear anyway.
The fields are always in the order
<code>:completion:``function``:``completer``:``command``:``argument``:``tag</code>.
These have the following meaning:</p>
<ul>
<li>The literal string <code>completion</code>, saying that this style is used by
the completion system. This distinguishes the context from those
used by, for example, zle widgets and ZFTP functions.</li>
<li>The <code>function</code>, if completion is called from a named widget rather
than through the normal completion system. Typically this is blank,
but it is set by special widgets such as <code>predict-on</code> and the
various functions in the <code>Widget</code> directory of the distribution to
the name of that function, often in an abbreviated form.</li>
<li>The <code>completer</code> currently active, the name of the function without
the leading underscore and with other underscores converted to
hyphens. A ‘completer’ is in overall control of how completion is to
be performed; ‘<code>complete</code>’ is the simplest, but other completers
exist to perform related tasks such as correction, or to modify the
behaviour of a later completer. See <a href="Completion-System.html#Control-Functions">Control
Functions</a> for more information.</li>
<li>The <code>command</code> or a special <code>-``context``-</code>, just at it appears
following the <code>#compdef</code> tag or the <code>compdef</code> function. Completion
functions for commands that have sub-commands usually modify this
field to contain the name of the command followed by a minus sign
and the sub-command. For example, the completion function for the
<code>cvs</code> command sets this field to <code>cvs-add</code> when completing arguments
to the <code>add</code> subcommand.</li>
<li>The <code>argument</code>; this indicates which command line or option argument
we are completing. For command arguments this generally takes the
form <code>argument-``n</code>, where <code>n</code> is the number of the argument, and
for arguments to options the form <code>option-``opt``-``n</code> where <code>n</code> is
the number of the argument to option <code>opt</code>. However, this is only
the case if the command line is parsed with standard UNIX-style
options and arguments, so many completions do not set this.</li>
<li>The <code>tag</code>. As described previously, tags are used to discriminate
between the types of matches a completion function can generate in a
certain context. Any completion function may use any tag name it
likes, but a list of the more common ones is given below.</li>
</ul>
<p>The context is gradually put together as the functions are executed,
starting with the main entry point, which adds <code>:completion:</code> and the
<code>function</code> element if necessary. The completer then adds the <code>completer</code>
element. The contextual completion adds the <code>command</code> and <code>argument</code>
options. Finally, the <code>tag</code> is added when the types of completion are
known. For example, the context name</p>
<div class="example">
<pre><code class="language-example">:completion::complete:dvips:option-o-1:files
</code></pre>
</div>
<p>says that normal completion was attempted as the first argument to the
option <code>-o</code> of the command <code>dvips</code>:</p>
<div class="example">
<pre><code class="language-example">dvips -o ...
</code></pre>
</div>
<p>and the completion function will generate filenames.</p>
<p>Usually completion will be tried for all possible tags in an order given
by the completion function. However, this can be altered by using the
<code>tag-order</code> style. Completion is then restricted to the list of given
tags in the given order.</p>
<p>The <code>_complete_help</code> bindable command shows all the contexts and tags
available for completion at a particular point. This provides an easy
way of finding information for <code>tag-order</code> and other styles. It is
described in <a href="Completion-System.html#Bindable-Commands">Bindable Commands</a>.</p>
<p>When looking up styles the completion system uses full context names,
including the tag. Looking up the value of a style therefore consists of
two things: the context, which is matched to the most specific (best
fitting) style pattern, and the name of the style itself, which must be
matched exactly. The following examples demonstrate that style patterns
may be loosely defined for styles that apply broadly, or as tightly
defined as desired for styles that apply in narrower circumstances.</p>
<p>For example, many completion functions can generate matches in a simple
and a verbose form and use the <code>verbose</code> style to decide which form
should be used. To make all such functions use the verbose form, put</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' verbose yes
</code></pre>
</div>
<p>in a startup file (probably <code>.zshrc</code>). This gives the <code>verbose</code> style
the value <code>yes</code> in every context inside the completion system, unless
that context has a more specific definition. It is best to avoid giving
the context as ‘<code>*</code>’ in case the style has some meaning outside the
completion system.</p>
<p>Many such general purpose styles can be configured simply by using the
<code>compinstall</code> function.</p>
<p>A more specific example of the use of the <code>verbose</code> style is by the
completion for the <code>kill</code> builtin. If the style is set, the builtin
lists full job texts and process command lines; otherwise it shows the
bare job numbers and PIDs. To turn the style off for this use only:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:kill:*:*' verbose no
</code></pre>
</div>
<p>For even more control, the style can use one of the tags ‘<code>jobs</code>’ or
‘<code>processes</code>’. To turn off verbose display only for jobs:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:kill:*:jobs' verbose no
</code></pre>
</div>
<p>The <code>-e</code> option to <code>zstyle</code> even allows completion function code to
appear as the argument to a style; this requires some understanding of
the internals of completion functions (see <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a>)). For example,</p>
<div class="example">
<pre><code class="language-example">zstyle -e ':completion:*' hosts 'reply=($myhosts)'
</code></pre>
</div>
<p>This forces the value of the <code>hosts</code> style to be read from the variable
<code>myhosts</code> each time a host name is needed; this is useful if the value
of <code>myhosts</code> can change dynamically. For another useful example, see the
example in the description of the <code>file-list</code> style below. This form can
be slow and should be avoided for commonly examined styles such as
<code>menu</code> and <code>list-rows-first</code>.</p>
<p>Note that the order in which styles are <em>defined</em> does not matter; the
style mechanism uses the most specific possible match for a particular
style to determine the set of values. More precisely, strings are
preferred over patterns (for example, ‘<code>:completion::complete:::foo</code>’ is
more specific than ‘<code>:completion::complete:::*’</code>), and longer patterns
are preferred over shorter patterns.</p>
<p>A good rule of thumb is that any completion style pattern that needs to
include more than one wildcard (<code>*</code>) and that does not end in a tag
name, should include all six colons (<code>:</code>), possibly surrounding
additional wildcards.</p>
<p>Style names like those of tags are arbitrary and depend on the
completion function. However, the following two sections list some of
the most common tags and styles.</p>
<hr />
<p><span id="Standard-Tags"></span></p>
<h3 id="2032-standard-tags"><a class="header" href="#2032-standard-tags">20.3.2 Standard Tags</a></h3>
<p><span id="index-completion-system_002c-tags"></span></p>
<p>Some of the following are only used when looking up particular styles
and do not refer to a type of match.</p>
<p><span id="index-accounts_002c-completion-tag"></span></p>
<p><code>accounts</code></p>
<p>used to look up the <code>users-hosts</code> style</p>
<p><span id="index-all_002dexpansions_002c-completion-tag"></span></p>
<p><code>all-expansions</code></p>
<p>used by the <code>_expand</code> completer when adding the single string containing
all possible expansions</p>
<p><span id="index-all_002dfiles_002c-completion-tag"></span></p>
<p><code>all-files</code></p>
<p>for the names of all files (as distinct from a particular subset, see
the <code>globbed-files</code> tag).</p>
<p><span id="index-arguments_002c-completion-tag"></span></p>
<p><code>arguments</code></p>
<p>for arguments to a command</p>
<p><span id="index-arrays_002c-completion-tag"></span></p>
<p><code>arrays</code></p>
<p>for names of array parameters</p>
<p><span id="index-association_002dkeys_002c-completion-tag"></span></p>
<p><code>association-keys</code></p>
<p>for keys of associative arrays; used when completing inside a subscript
to a parameter of this type</p>
<p><span id="index-bookmarks_002c-completion-tag"></span></p>
<p><code>bookmarks</code></p>
<p>when completing bookmarks (e.g. for URLs and the <code>zftp</code> function suite)</p>
<p><span id="index-builtins_002c-completion-tag"></span></p>
<p><code>builtins</code></p>
<p>for names of builtin commands</p>
<p><span id="index-characters_002c-completion-tag"></span></p>
<p><code>characters</code></p>
<p>for single characters in arguments of commands such as <code>stty</code>. Also used
when completing character classes after an opening bracket</p>
<p><span id="index-colormapids_002c-completion-tag"></span></p>
<p><code>colormapids</code></p>
<p>for X colormap ids</p>
<p><span id="index-colors_002c-completion-tag"></span></p>
<p><code>colors</code></p>
<p>for color names</p>
<p><span id="index-commands_002c-completion-tag"></span></p>
<p><code>commands</code></p>
<p>for names of external commands. Also used by complex commands such as
<code>cvs</code> when completing names subcommands.</p>
<p><span id="index-contexts_002c-completion-tag"></span></p>
<p><code>contexts</code></p>
<p>for contexts in arguments to the <code>zstyle</code> builtin command</p>
<p><span id="index-corrections_002c-completion-tag"></span></p>
<p><code>corrections</code></p>
<p>used by the <code>_approximate</code> and <code>_correct</code> completers for possible
corrections</p>
<p><span id="index-cursors_002c-completion-tag"></span></p>
<p><code>cursors</code></p>
<p>for cursor names used by X programs</p>
<p><span id="index-default_002c-completion-tag"></span></p>
<p><code>default</code></p>
<p>used in some contexts to provide a way of supplying a default when more
specific tags are also valid. Note that this tag is used when only the
<code>function</code> field of the context name is set</p>
<p><span id="index-descriptions_002c-completion-tag"></span></p>
<p><code>descriptions</code></p>
<p>used when looking up the value of the <code>format</code> style to generate
descriptions for types of matches</p>
<p><span id="index-devices_002c-completion-tag"></span></p>
<p><code>devices</code></p>
<p>for names of device special files</p>
<p><span id="index-directories_002c-completion-tag"></span></p>
<p><code>directories</code></p>
<p>for names of directories — <code>local-directories</code> is used instead when
completing arguments of <code>cd</code> and related builtin commands when the
<code>cdpath</code> array is set</p>
<p><span id="index-directory_002dstack_002c-completion-tag"></span></p>
<p><code>directory-stack</code></p>
<p>for entries in the directory stack</p>
<p><span id="index-displays_002c-completion-tag"></span></p>
<p><code>displays</code></p>
<p>for X display names</p>
<p><span id="index-domains_002c-completion-tag"></span></p>
<p><code>domains</code></p>
<p>for network domains</p>
<p><span id="index-email_002d_002a_002c-completion-tag"></span></p>
<p><code>email-``plugin</code></p>
<p>for email addresses from the ‘<code>_email-``plugin</code>’ backend of
<code>_email_addresses</code></p>
<p><span id="index-expansions_002c-completion-tag"></span></p>
<p><code>expansions</code></p>
<p>used by the <code>_expand</code> completer for individual words (as opposed to the
complete set of expansions) resulting from the expansion of a word on
the command line</p>
<p><span id="index-extensions_002c-completion-tag"></span></p>
<p><code>extensions</code></p>
<p>for X server extensions</p>
<p><span id="index-file_002ddescriptors_002c-completion-tag"></span></p>
<p><code>file-descriptors</code></p>
<p>for numbers of open file descriptors</p>
<p><span id="index-files_002c-completion-tag"></span></p>
<p><code>files</code></p>
<p>the generic file-matching tag used by functions completing filenames</p>
<p><span id="index-fonts_002c-completion-tag"></span></p>
<p><code>fonts</code></p>
<p>for X font names</p>
<p><span id="index-fstypes_002c-completion-tag"></span></p>
<p><code>fstypes</code></p>
<p>for file system types (e.g. for the <code>mount</code> command)</p>
<p><span id="index-functions_002c-completion-tag"></span></p>
<p><code>functions</code></p>
<p>names of functions — normally shell functions, although certain commands
may understand other kinds of function</p>
<p><span id="index-globbed_002dfiles_002c-completion-tag"></span></p>
<p><code>globbed-files</code></p>
<p>for filenames when the name has been generated by pattern matching</p>
<p><span id="index-groups_002c-completion-tag"></span></p>
<p><code>groups</code></p>
<p>for names of user groups</p>
<p><span id="index-history_002dwords_002c-completion-tag"></span></p>
<p><code>history-words</code></p>
<p>for words from the history</p>
<p><span id="index-hosts_002c-completion-tag"></span></p>
<p><code>hosts</code></p>
<p>for hostnames</p>
<p><span id="index-indexes_002c-completion-tag"></span></p>
<p><code>indexes</code></p>
<p>for array indexes</p>
<p><span id="index-jobs_002c-completion-tag"></span></p>
<p><code>jobs</code></p>
<p>for jobs (as listed by the ‘<code>jobs</code>’ builtin)</p>
<p><span id="index-interfaces_002c-completion-tag"></span></p>
<p><code>interfaces</code></p>
<p>for network interfaces</p>
<p><span id="index-keymaps_002c-completion-tag"></span></p>
<p><code>keymaps</code></p>
<p>for names of zsh keymaps</p>
<p><span id="index-keysyms_002c-completion-tag"></span></p>
<p><code>keysyms</code></p>
<p>for names of X keysyms</p>
<p><span id="index-libraries_002c-completion-tag"></span></p>
<p><code>libraries</code></p>
<p>for names of system libraries</p>
<p><span id="index-limits_002c-completion-tag"></span></p>
<p><code>limits</code></p>
<p>for system limits</p>
<p><span id="index-local_002ddirectories_002c-completion-tag"></span></p>
<p><code>local-directories</code></p>
<p>for names of directories that are subdirectories of the current working
directory when completing arguments of <code>cd</code> and related builtin commands
(compare <code>path-directories</code>) — when the <code>cdpath</code> array is unset,
<code>directories</code> is used instead</p>
<p><span id="index-manuals_002c-completion-tag"></span></p>
<p><code>manuals</code></p>
<p>for names of manual pages</p>
<p><span id="index-mailboxes_002c-completion-tag"></span></p>
<p><code>mailboxes</code></p>
<p>for e-mail folders</p>
<p><span id="index-maps_002c-completion-tag"></span></p>
<p><code>maps</code></p>
<p>for map names (e.g. NIS maps)</p>
<p><span id="index-messages_002c-completion-tag"></span></p>
<p><code>messages</code></p>
<p>used to look up the <code>format</code> style for messages</p>
<p><span id="index-modifiers_002c-completion-tag"></span></p>
<p><code>modifiers</code></p>
<p>for names of X modifiers</p>
<p><span id="index-modules_002c-completion-tag"></span></p>
<p><code>modules</code></p>
<p>for modules (e.g. <code>zsh</code> modules)</p>
<p><span id="index-my_002daccounts_002c-completion-tag"></span></p>
<p><code>my-accounts</code></p>
<p>used to look up the <code>users-hosts</code> style</p>
<p><span id="index-named_002ddirectories_002c-completion-tag"></span></p>
<p><code>named-directories</code></p>
<p>for named directories (you wouldn’t have guessed that, would you?)</p>
<p><span id="index-names_002c-completion-tag"></span></p>
<p><code>names</code></p>
<p>for all kinds of names</p>
<p><span id="index-newsgroups_002c-completion-tag"></span></p>
<p><code>newsgroups</code></p>
<p>for USENET groups</p>
<p><span id="index-nicknames_002c-completion-tag"></span></p>
<p><code>nicknames</code></p>
<p>for nicknames of NIS maps</p>
<p><span id="index-options_002c-completion-tag"></span></p>
<p><code>options</code></p>
<p>for command options</p>
<p><span id="index-original_002c-completion-tag"></span></p>
<p><code>original</code></p>
<p>used by the <code>_approximate</code>, <code>_correct</code> and <code>_expand</code> completers when
offering the original string as a match</p>
<p><span id="index-other_002daccounts_002c-completion-tag"></span></p>
<p><code>other-accounts</code></p>
<p>used to look up the <code>users-hosts</code> style</p>
<p><span id="index-other_002dfiles_002c-completion-tag"></span></p>
<p><code>other-files</code></p>
<p>for the names of any non-directory files. This is used instead of
<code>all-files</code> when the <code>list-dirs-first</code> style is in effect.</p>
<p><span id="index-packages_002c-completion-tag"></span></p>
<p><code>packages</code></p>
<p>for packages (e.g. <code>rpm</code> or installed <code>Debian</code> packages)</p>
<p><span id="index-parameters_002c-completion-tag"></span></p>
<p><code>parameters</code></p>
<p>for names of parameters</p>
<p><span id="index-path_002ddirectories_002c-completion-tag"></span></p>
<p><code>path-directories</code></p>
<p>for names of directories found by searching the <code>cdpath</code> array when
completing arguments of <code>cd</code> and related builtin commands (compare
<code>local-directories</code>)</p>
<p><span id="index-paths_002c-completion-tag"></span></p>
<p><code>paths</code></p>
<p>used to look up the values of the <code>expand</code>, <code>ambiguous</code> and
<code>special-dirs</code> styles</p>
<p><span id="index-pods_002c-completion-tag"></span></p>
<p><code>pods</code></p>
<p>for perl pods (documentation files)</p>
<p><span id="index-ports_002c-completion-tag"></span></p>
<p><code>ports</code></p>
<p>for communication ports</p>
<p><span id="index-prefixes_002c-completion-tag"></span></p>
<p><code>prefixes</code></p>
<p>for prefixes (like those of a URL)</p>
<p><span id="index-printers_002c-completion-tag"></span></p>
<p><code>printers</code></p>
<p>for print queue names</p>
<p><span id="index-processes_002c-completion-tag"></span></p>
<p><code>processes</code></p>
<p>for process identifiers</p>
<p><span id="index-processes_002dnames_002c-completion-tag"></span></p>
<p><code>processes-names</code></p>
<p>used to look up the <code>command</code> style when generating the names of
processes for <code>killall</code></p>
<p><span id="index-sequences_002c-completion-tag"></span></p>
<p><code>sequences</code></p>
<p>for sequences (e.g. <code>mh</code> sequences)</p>
<p><span id="index-sessions_002c-completion-tag"></span></p>
<p><code>sessions</code></p>
<p>for sessions in the <code>zftp</code> function suite</p>
<p><span id="index-signals_002c-completion-tag"></span></p>
<p><code>signals</code></p>
<p>for signal names</p>
<p><span id="index-strings_002c-completion-tag"></span></p>
<p><code>strings</code></p>
<p>for strings (e.g. the replacement strings for the <code>cd</code> builtin command)</p>
<p><span id="index-styles_002c-completion-tag"></span></p>
<p><code>styles</code></p>
<p>for styles used by the zstyle builtin command</p>
<p><span id="index-suffixes_002c-completion-tag"></span></p>
<p><code>suffixes</code></p>
<p>for filename extensions</p>
<p><span id="index-tags_002c-completion-tag"></span></p>
<p><code>tags</code></p>
<p>for tags (e.g. <code>rpm</code> tags)</p>
<p><span id="index-targets_002c-completion-tag"></span></p>
<p><code>targets</code></p>
<p>for makefile targets</p>
<p><span id="index-time_002dzones_002c-completion-tag"></span></p>
<p><code>time-zones</code></p>
<p>for time zones (e.g. when setting the <code>TZ</code> parameter)</p>
<p><span id="index-types_002c-completion-tag"></span></p>
<p><code>types</code></p>
<p>for types of whatever (e.g. address types for the <code>xhost</code> command)</p>
<p><span id="index-urls_002c-completion-tag"></span></p>
<p><code>urls</code></p>
<p>used to look up the <code>urls</code> and <code>local</code> styles when completing URLs</p>
<p><span id="index-users_002c-completion-tag"></span></p>
<p><code>users</code></p>
<p>for usernames</p>
<p><span id="index-values_002c-completion-tag"></span></p>
<p><code>values</code></p>
<p>for one of a set of values in certain lists</p>
<p><span id="index-variant_002c-completion-tag"></span></p>
<p><code>variant</code></p>
<p>used by <code>_pick_variant</code> to look up the command to run when determining
what program is installed for a particular command name.</p>
<p><span id="index-visuals_002c-completion-tag"></span></p>
<p><code>visuals</code></p>
<p>for X visuals</p>
<p><span id="index-warnings_002c-completion-tag"></span></p>
<p><code>warnings</code></p>
<p>used to look up the <code>format</code> style for warnings</p>
<p><span id="index-widgets_002c-completion-tag"></span></p>
<p><code>widgets</code></p>
<p>for zsh widget names</p>
<p><span id="index-windows_002c-completion-tag"></span></p>
<p><code>windows</code></p>
<p>for IDs of X windows</p>
<p><span id="index-zsh_002doptions_002c-completion-tag"></span></p>
<p><code>zsh-options</code></p>
<p>for shell options</p>
<hr />
<p><span id="Standard-Styles"></span></p>
<h3 id="2033-standard-styles"><a class="header" href="#2033-standard-styles">20.3.3 Standard Styles</a></h3>
<p><span id="index-completion-system_002c-styles"></span></p>
<p>Note that the values of several of these styles represent boolean
values. Any of the strings ‘<code>true</code>’, ‘<code>on</code>’, ‘<code>yes</code>’, and ‘<code>1</code>’ can be
used for the value ‘true’ and any of the strings ‘<code>false</code>’, ‘<code>off</code>’,
‘<code>no</code>’, and ‘<code>0</code>’ for the value ‘false’. The behavior for any other
value is undefined except where explicitly mentioned. The default value
may be either ‘true’ or ‘false’ if the style is not set.</p>
<p>Some of these styles are tested first for every possible tag
corresponding to a type of match, and if no style was found, for the
<code>list-colors</code> and styles controlling completion listing such as
<code>list-packed</code> and <code>last-prompt</code>. When tested for the <code>default</code> tag, only
the <code>function</code> field of the context will be set so that a style using
the <code>default</code> tag will normally be defined along the lines of:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:default' menu ...
</code></pre>
</div>
<p><span id="index-accept_002dexact_002c-completion-style"></span></p>
<p><code>accept-exact</code></p>
<p>This is tested for the <code>default</code> tag in addition to the tags valid for
the current context. If it is set to ‘true’ and any of the trial matches
is the same as the string on the command line, this match will
immediately be accepted (even if it would otherwise be considered
ambiguous).</p>
<p>When completing pathnames (where the tag used is ‘<code>paths</code>’) this style
accepts any number of patterns as the value in addition to the boolean
values. Pathnames matching one of these patterns will be accepted
immediately even if the command line contains some more partially typed
pathname components and these match no file under the directory
accepted.</p>
<p>This style is also used by the <code>_expand</code> completer to decide if words
beginning with a tilde or parameter expansion should be expanded. For
example, if there are parameters <code>foo</code> and <code>foobar</code>, the string ‘<code>$foo</code>’
will only be expanded if <code>accept-exact</code> is set to ‘true’; otherwise the
completion system will be allowed to complete <code>$foo</code> to <code>$foobar</code>. If
the style is set to ‘<code>continue</code>’, <code>_expand</code> will add the expansion as a
match and the completion system will also be allowed to continue.</p>
<p><span id="index-accept_002dexact_002ddirs_002c-completion-style"></span></p>
<p><code>accept-exact-dirs</code></p>
<p>This is used by filename completion. Unlike <code>accept-exact</code> it is a
boolean. By default, filename completion examines all components of a
path to see if there are completions of that component, even if the
component matches an existing directory. For example, when completion
after <code>/usr/bin/</code>, the function examines possible completions to <code>/usr</code>.</p>
<p>When this style is ‘true’, any prefix of a path that matches an existing
directory is accepted without any attempt to complete it further. Hence,
in the given example, the path <code>/usr/bin/</code> is accepted immediately and
completion tried in that directory.</p>
<p>This style is also useful when completing after directories that
magically appear when referenced, such as ZFS <code>.zfs</code> directories or
NetApp <code>.snapshot</code> directories. When the style is set the shell does not
check for the existence of the directory within the parent directory.</p>
<p>If you wish to inhibit this behaviour entirely, set the
<code>path-completion</code> style (see below) to ‘false’.</p>
<p><span id="index-add_002dspace_002c-completion-style"></span></p>
<p><code>add-space</code></p>
<p>This style is used by the <code>_expand</code> completer. If it is ‘true’ (the
default), a space will be inserted after all words resulting from the
expansion, or a slash in the case of directory names. If the value is
‘<code>file</code>’, the completer will only add a space to names of existing
files. Either a boolean ‘true’ or the value ‘<code>file</code>’ may be combined
with ‘<code>subst</code>’, in which case the completer will not add a space to
words generated from the expansion of a substitution of the form
‘<code>$(``...``)</code>’ or ‘<code>${``...``}</code>’.</p>
<p>The <code>_prefix</code> completer uses this style as a simple boolean value to
decide if a space should be inserted before the suffix.</p>
<p><span id="index-ambiguous_002c-completion-style"></span></p>
<p><code>ambiguous</code></p>
<p>This applies when completing non-final components of filename paths, in
other words those with a trailing slash. If it is set, the cursor is
left after the first ambiguous component, even if menu completion is in
use. The style is always tested with the <code>paths</code> tag.</p>
<p><span id="index-assign_002dlist_002c-completion-style"></span></p>
<p><code>assign-list</code></p>
<p>When completing after an equals sign that is being treated as an
assignment, the completion system normally completes only one filename.
In some cases the value may be a list of filenames separated by colons,
as with <code>PATH</code> and similar parameters. This style can be set to a list
of patterns matching the names of such parameters.</p>
<p>The default is to complete lists when the word on the line already
contains a colon.</p>
<p><span id="index-auto_002ddescription_002c-completion-style"></span></p>
<p><code>auto-description</code></p>
<p>If set, this style’s value will be used as the description for options
that are not described by the completion functions, but that have
exactly one argument. The sequence ‘<code>%d</code>’ in the value will be replaced
by the description for this argument. Depending on personal preferences,
it may be useful to set this style to something like ‘<code>specify: %d</code>’.
Note that this may not work for some commands.</p>
<p><span id="index-avoid_002dcompleter_002c-completion-style"></span></p>
<p><code>avoid-completer</code></p>
<p>This is used by the <code>_all_matches</code> completer to decide if the string
consisting of all matches should be added to the list currently being
generated. Its value is a list of names of completers. If any of these
is the name of the completer that generated the matches in this
completion, the string will not be added.</p>
<p>The default value for this style is ‘<code>_expand _old_list _correct _approximate</code>’, i.e. it contains the completers for which a string with
all matches will almost never be wanted.</p>
<p><span id="index-cache_002dpath_002c-completion-style"></span></p>
<p><code>cache-path</code></p>
<p>This style defines the path where any cache files containing dumped
completion data are stored. It defaults to ‘<code>$ZDOTDIR/.zcompcache</code>’, or
‘<code>$HOME/.zcompcache</code>’ if <code>$ZDOTDIR</code> is not defined. The completion
cache will not be used unless the <code>use-cache</code> style is set.</p>
<p><span id="index-cache_002dpolicy_002c-completion-style"></span></p>
<p><code>cache-policy</code></p>
<p>This style defines the function that will be used to determine whether a
cache needs rebuilding. See the section on the <code>_cache_invalid</code> function
below.</p>
<p><span id="index-call_002dcommand_002c-completion-style"></span></p>
<p><code>call-command</code></p>
<p>This style is used in the function for commands such as <code>make</code> and <code>ant</code>
where calling the command directly to generate matches suffers problems
such as being slow or, as in the case of <code>make</code> can potentially cause
actions in the makefile to be executed. If it is set to ‘true’ the
command is called to generate matches. The default value of this style
is ‘false’.</p>
<p><span id="index-command_002c-completion-style"></span></p>
<p><code>command</code></p>
<p>In many places, completion functions need to call external commands to
generate the list of completions. This style can be used to override the
command that is called in some such cases. The elements of the value are
joined with spaces to form a command line to execute. The value can also
start with a hyphen, in which case the usual command will be added to
the end; this is most useful for putting ‘<code>builtin</code>’ or ‘<code>command</code>’ in
front to make sure the appropriate version of a command is called, for
example to avoid calling a shell function with the same name as an
external command.</p>
<p>As an example, the completion function for process IDs uses this style
with the <code>processes</code> tag to generate the IDs to complete and the list of
processes to display (if the <code>verbose</code> style is ‘true’). The list
produced by the command should look like the output of the <code>ps</code> command.
The first line is not displayed, but is searched for the string ‘<code>PID</code>’
(or ‘<code>pid</code>’) to find the position of the process IDs in the following
lines. If the line does not contain ‘<code>PID</code>’, the first numbers in each
of the other lines are taken as the process IDs to complete.</p>
<p>Note that the completion function generally has to call the specified
command for each attempt to generate the completion list. Hence care
should be taken to specify only commands that take a short time to run,
and in particular to avoid any that may never terminate.</p>
<p><span id="index-command_002dpath_002c-completion-style"></span></p>
<p><code>command-path</code></p>
<p>This is a list of directories to search for commands to complete. The
default for this style is the value of the special parameter <code>path</code>.</p>
<p><span id="index-commands_002c-completion-style"></span></p>
<p><code>commands</code></p>
<p>This is used by the function completing sub-commands for the system
initialisation scripts (residing in <code>/etc/init.d</code> or somewhere not too
far away from that). Its values give the default commands to complete
for those commands for which the completion function isn’t able to find
them out automatically. The default for this style are the two strings
‘<code>start</code>’ and ‘<code>stop</code>’.</p>
<p><span id="index-complete_002c-completion-style"></span></p>
<p><code>complete</code></p>
<p>This is used by the <code>_expand_alias</code> function when invoked as a bindable
command. If set to ‘true’ and the word on the command line is not the
name of an alias, matching alias names will be completed.</p>
<p><span id="index-complete_002doptions_002c-completion-style"></span></p>
<p><code>complete-options</code></p>
<p>This is used by the completer for <code>cd</code>, <code>chdir</code> and <code>pushd</code>. For these
commands a <code>-</code> is used to introduce a directory stack entry and
completion of these is far more common than completing options. Hence
unless the value of this style is ‘true’ options will not be completed,
even after an initial <code>-</code>. If it is ‘true’, options will be completed
after an initial <code>-</code> unless there is a preceding <code>-``-</code> on the command
line.</p>
<p><span id="index-completer_002c-completion-style"></span></p>
<p><code>completer</code></p>
<p>The strings given as the value of this style provide the names of the
completer functions to use. The available completer functions are
described in <a href="Completion-System.html#Control-Functions">Control Functions</a>.</p>
<p>Each string may be either the name of a completer function or a string
of the form ‘<code>function``:``name</code>’. In the first case the <code>completer</code>
field of the context will contain the name of the completer without the
leading underscore and with all other underscores replaced by hyphens.
In the second case the <code>function</code> is the name of the completer to call,
but the context will contain the user-defined <code>name</code> in the <code>completer</code>
field of the context. If the <code>name</code> starts with a hyphen, the string for
the context will be build from the name of the completer function as in
the first case with the <code>name</code> appended to it. For example:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer _complete _complete:-foo
</code></pre>
</div>
<p>Here, completion will call the <code>_complete</code> completer twice, once using
‘<code>complete</code>’ and once using ‘<code>complete-foo</code>’ in the <code>completer</code> field
of the context. Normally, using the same completer more than once only
makes sense when used with the ‘<code>functions``:``name</code>’ form, because
otherwise the context name will be the same in all calls to the
completer; possible exceptions to this rule are the <code>_ignored</code> and
<code>_prefix</code> completers.</p>
<p>The default value for this style is ‘<code>_complete _ignored</code>’: only
completion will be done, first using the <code>ignored-patterns</code> style and
the <code>$fignore</code> array and then without ignoring matches.</p>
<p><span id="index-condition_002c-completion-style"></span></p>
<p><code>condition</code></p>
<p>This style is used by the <code>_list</code> completer function to decide if
insertion of matches should be delayed unconditionally. The default is
‘true’.</p>
<p><span id="index-delimiters_002c-completion-style"></span></p>
<p><code>delimiters</code></p>
<p>This style is used when adding a delimiter for use with history
modifiers or glob qualifiers that have delimited arguments. It is an
array of preferred delimiters to add. Non-special characters are
preferred as the completion system may otherwise become confused. The
default list is <code>:</code>, <code>+</code>, <code>/</code>, <code>-</code>, <code>%</code>. The list may be empty to force
a delimiter to be typed.</p>
<p><span id="index-disabled_002c-completion-style"></span></p>
<p><code>disabled</code></p>
<p>If this is set to ‘true’, the <code>_expand_alias</code> completer and bindable
command will try to expand disabled aliases, too. The default is
‘false’.</p>
<p><span id="index-domains_002c-completion-style"></span></p>
<p><code>domains</code></p>
<p>A list of names of network domains for completion. If this is not set,
domain names will be taken from the file <code>/etc/resolv.conf</code>.</p>
<p><span id="index-environ_002c-completion-style"></span></p>
<p><code>environ</code></p>
<p>The environ style is used when completing for ‘<code>sudo</code>’. It is set to an
array of ‘<code>VAR``=``value</code>’ assignments to be exported into the local
environment before the completion for the target command is invoked.</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:sudo::' environ \
PATH=&quot;/sbin:/usr/sbin:$PATH&quot; HOME=&quot;/root&quot;
</code></pre>
</div>
<p><span id="index-expand_002c-completion-style"></span></p>
<p><code>expand</code></p>
<p>This style is used when completing strings consisting of multiple parts,
such as path names.</p>
<p>If one of its values is the string ‘<code>prefix</code>’, the partially typed word
from the line will be expanded as far as possible even if trailing parts
cannot be completed.</p>
<p>If one of its values is the string ‘<code>suffix</code>’, matching names for
components after the first ambiguous one will also be added. This means
that the resulting string is the longest unambiguous string possible.
However, menu completion can be used to cycle through all matches.</p>
<p><span id="index-fake_002c-completion-style"></span></p>
<p><code>fake</code></p>
<p>This style may be set for any completion context. It specifies
additional strings that will always be completed in that context. The
form of each string is ‘<code>value``:``description</code>’; the colon and
description may be omitted, but any literal colons in <code>value</code> must be
quoted with a backslash. Any <code>description</code> provided is shown alongside
the value in completion listings.</p>
<p>It is important to use a sufficiently restrictive context when
specifying fake strings. Note that the styles <code>fake-files</code> and
<code>fake-parameters</code> provide additional features when completing files or
parameters.</p>
<p><span id="index-fake_002dalways_002c-completion-style"></span></p>
<p><code>fake-always</code></p>
<p>This works identically to the <code>fake</code> style except that the
<code>ignored-patterns</code> style is not applied to it. This makes it possible to
override a set of matches completely by setting the ignored patterns to
‘<code>*</code>’.</p>
<p>The following shows a way of supplementing any tag with arbitrary data,
but having it behave for display purposes like a separate tag. In this
example we use the features of the <code>tag-order</code> style to divide the
<code>named-directories</code> tag into two when performing completion with the
standard completer <code>complete</code> for arguments of <code>cd</code>. The tag
<code>named-directories-normal</code> behaves as normal, but the tag
<code>named-directories-mine</code> contains a fixed set of directories. This has
the effect of adding the match group ‘<code>extra directories</code>’ with the
given completions.</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion::complete:cd:*' tag-order \
'named-directories:-mine:extra\ directories
named-directories:-normal:named\ directories *'
zstyle ':completion::complete:cd:*:named-directories-mine' \
fake-always mydir1 mydir2
zstyle ':completion::complete:cd:*:named-directories-mine' \
ignored-patterns '*'
</code></pre>
</div>
<p><span id="index-fake_002dfiles_002c-completion-style"></span></p>
<p><code>fake-files</code></p>
<p>This style is used when completing files and looked up without a tag.
Its values are of the form ‘<code>dir``:``names...</code>’. This will add the
<code>names</code> (strings separated by spaces) as possible matches when
completing in the directory <code>dir</code>, even if no such files really exist.
The dir may be a pattern; pattern characters or colons in <code>dir</code> should
be quoted with a backslash to be treated literally.</p>
<p>This can be useful on systems that support special file systems whose
top-level pathnames can not be listed or generated with glob patterns
(but see <code>accept-exact-dirs</code> for a more general way of dealing with this
problem). It can also be used for directories for which one does not
have read permission.</p>
<p>The pattern form can be used to add a certain ‘magic’ entry to all
directories on a particular file system.</p>
<p><span id="index-fake_002dparameters_002c-completion-style"></span></p>
<p><code>fake-parameters</code></p>
<p>This is used by the completion function for parameter names. Its values
are names of parameters that might not yet be set but should be
completed nonetheless. Each name may also be followed by a colon and a
string specifying the type of the parameter (like ‘<code>scalar</code>’, ‘<code>array</code>’
or ‘<code>integer</code>’). If the type is given, the name will only be completed
if parameters of that type are required in the particular context. Names
for which no type is specified will always be completed.</p>
<p><span id="index-file_002dlist_002c-completion-style"></span></p>
<p><code>file-list</code></p>
<p>This style controls whether files completed using the standard builtin
mechanism are to be listed with a long list similar to <code>ls -l</code>. Note
that this feature uses the shell module <code>zsh/stat</code> for file information;
this loads the builtin <code>stat</code> this the following code can be included in
an initialization file:</p>
<div class="example">
<pre><code class="language-example">zmodload -i zsh/stat
disable stat
</code></pre>
</div>
<p>The style may either be set to a ‘true’ value (or ‘<code>all</code>’), or one of
the values ‘<code>insert</code>’ or ‘<code>list</code>’, indicating that files are to be
listed in long format in all circumstances, or when attempting to insert
a file name, or when listing file names without attempting to insert
one.</p>
<p>More generally, the value may be an array of any of the above values,
optionally followed by <code>=``num</code>. If <code>num</code> is present it gives the
maximum number of matches for which long listing style will be used. For
example,</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' file-list list=20 insert=10
</code></pre>
</div>
<p>specifies that long format will be used when listing up to 20 files or
inserting a file with up to 10 matches (assuming a listing is to be
shown at all, for example on an ambiguous completion), else short format
will be used.</p>
<div class="example">
<pre><code class="language-example">zstyle -e ':completion:*' file-list \
'(( ${+NUMERIC} )) &amp;&amp; reply=(true)'
</code></pre>
</div>
<p>specifies that long format will be used any time a numeric argument is
supplied, else short format.</p>
<p><span id="index-file_002dpatterns_002c-completion-style"></span></p>
<p><code>file-patterns</code></p>
<p>This is used by the standard function for completing filenames,
<code>_files</code>. If the style is unset up to three tags are offered,
‘<code>globbed-files</code>’,‘<code>directories</code>’ and ‘<code>all-files</code>’, depending on the
types of files expected by the caller of <code>_files</code>. The first two
(‘<code>globbed-files</code>’ and ‘<code>directories</code>’) are normally offered together
to make it easier to complete files in sub-directories.</p>
<p>The <code>file-patterns</code> style provides alternatives to the default tags,
which are not used. Its value consists of elements of the form
‘<code>pattern``:``tag</code>’; each string may contain any number of such
specifications separated by spaces.</p>
<p>The <code>pattern</code> is a pattern that is to be used to generate filenames. Any
occurrence of the sequence ‘<code>%p</code>’ is replaced by any pattern(s) passed
by the function calling <code>_files</code>. Colons in the pattern must be preceded
by a backslash to make them distinguishable from the colon before the
<code>tag</code>. If more than one pattern is needed, the patterns can be given
inside braces, separated by commas.</p>
<p>The <code>tag</code>s of all strings in the value will be offered by <code>_files</code> and
used when looking up other styles. Any <code>tag</code>s in the same word will be
offered at the same time and before later words. If no ‘<code>:``tag</code>’ is
given the ‘<code>files</code>’ tag will be used.</p>
<p>The <code>tag</code> may also be followed by an optional second colon and a
description, which will be used for the ‘<code>%d</code>’ in the value of the
<code>format</code> style (if that is set) instead of the default description
supplied by the completion function. If the description given here
contains itself a ‘<code>%d</code>’, that is replaced with the description supplied
by the completion function.</p>
<p>For example, to make the <code>rm</code> command first complete only names of
object files and then the names of all files if there is no matching
object file:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:rm:*:*' file-patterns \
'*.o:object-files' '%p:all-files'
</code></pre>
</div>
<p>To alter the default behaviour of file completion — offer files matching
a pattern and directories on the first attempt, then all files — to
offer only matching files on the first attempt, then directories, and
finally all files:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' file-patterns \
'%p:globbed-files' '*(-/):directories' '*:all-files'
</code></pre>
</div>
<p>This works even where there is no special pattern: <code>_files</code> matches all
files using the pattern ‘<code>*</code>’ at the first step and stops when it sees
this pattern. Note also it will never try a pattern more than once for a
single completion attempt.</p>
<p>During the execution of completion functions, the <code>EXTENDED_GLOB</code> option
is in effect, so the characters ‘<code>#</code>’, ‘<code>~</code>’ and ‘<code>^</code>’ have special
meanings in the patterns.</p>
<p><span id="index-file_002dsort_002c-completion-style"></span></p>
<p><code>file-sort</code></p>
<p>The standard filename completion function uses this style without a tag
to determine in which order the names should be listed; menu completion
will cycle through them in the same order. The possible values are:
‘<code>size</code>’ to sort by the size of the file; ‘<code>links</code>’ to sort by the
number of links to the file; ‘<code>modification</code>’ (or ‘<code>time</code>’ or ‘<code>date</code>’)
to sort by the last modification time; ‘<code>access</code>’ to sort by the last
access time; and ‘<code>inode</code>’ (or ‘<code>change</code>’) to sort by the last inode
change time. If the style is set to any other value, or is unset, files
will be sorted alphabetically by name. If the value contains the string
‘<code>reverse</code>’, sorting is done in the opposite order. If the value
contains the string ‘<code>follow</code>’, timestamps are associated with the
targets of symbolic links; the default is to use the timestamps of the
links themselves.</p>
<p><span id="index-file_002dsplit_002dchars_002c-completion-style"></span></p>
<p><code>file-split-chars</code></p>
<p>A set of characters that will cause <em>all</em> file completions for the given
context to be split at the point where any of the characters occurs. A
typical use is to set the style to <code>:</code>; then everything up to and
including the last <code>:</code> in the string so far is ignored when completing
files. As this is quite heavy-handed, it is usually preferable to update
completion functions for contexts where this behaviour is useful.</p>
<p><span id="index-filter_002c-completion-style"></span></p>
<p><code>filter</code></p>
<p>The <code>ldap</code> plugin of email address completion (see <code>_email_addresses</code>)
uses this style to specify the attributes to match against when
filtering entries. So for example, if the style is set to ‘<code>sn</code>’,
matching is done against surnames. Standard LDAP filtering is used so
normal completion matching is bypassed. If this style is not set, the
LDAP plugin is skipped. You may also need to set the <code>command</code> style to
specify how to connect to your LDAP server.</p>
<p><span id="index-force_002dlist_002c-completion-style"></span></p>
<p><code>force-list</code></p>
<p>This forces a list of completions to be shown at any point where listing
is done, even in cases where the list would usually be suppressed. For
example, normally the list is only shown if there are at least two
different matches. By setting this style to ‘<code>always</code>’, the list will
always be shown, even if there is only a single match that will
immediately be accepted. The style may also be set to a number. In this
case the list will be shown if there are at least that many matches,
even if they would all insert the same string.</p>
<p>This style is tested for the default tag as well as for each tag valid
for the current completion. Hence the listing can be forced only for
certain types of match.</p>
<p><span id="index-format_002c-completion-style"></span></p>
<p><code>format</code></p>
<p>If this is set for the <code>descriptions</code> tag, its value is used as a string
to display above matches in completion lists. The sequence ‘<code>%d</code>’ in
this string will be replaced with a short description of what these
matches are. This string may also contain the output attribute sequences
understood by <code>compadd -X</code> (see <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a>).</p>
<p>The style is tested with each tag valid for the current completion
before it is tested for the <code>descriptions</code> tag. Hence different format
strings can be defined for different types of match.</p>
<p>Note also that some completer functions define additional
‘<code>%</code>’-sequences. These are described for the completer functions
that make use of them.</p>
<p>Some completion functions display messages that may be customised by
setting this style for the <code>messages</code> tag. Here, the ‘<code>%d</code>’ is replaced
with a message given by the completion function.</p>
<p>Finally, the format string is looked up with the <code>warnings</code> tag, for use
when no matches could be generated at all. In this case the ‘<code>%d</code>’ is
replaced with the descriptions for the matches that were expected
separated by spaces. The sequence ‘<code>%D</code>’ is replaced with the same
descriptions separated by newlines.</p>
<p>It is possible to use printf-style field width specifiers with ‘<code>%d</code>’
and similar escape sequences. This is handled by the <code>zformat</code> builtin
command from the <code>zsh/zutil</code> module, see <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a>.</p>
<p><span id="index-glob_002c-completion-style"></span></p>
<p><code>glob</code></p>
<p>This is used by the <code>_expand</code> completer. If it is set to ‘true’ (the
default), globbing will be attempted on the words resulting from a
previous substitution (see the <code>substitute</code> style) or else the original
string from the line.</p>
<p><span id="index-global_002c-completion-style"></span></p>
<p><code>global</code></p>
<p>If this is set to ‘true’ (the default), the <code>_expand_alias</code> completer
and bindable command will try to expand global aliases.</p>
<p><span id="index-group_002dname_002c-completion-style"></span></p>
<p><code>group-name</code></p>
<p>The completion system can group different types of matches, which appear
in separate lists. This style can be used to give the names of groups
for particular tags. For example, in command position the completion
system generates names of builtin and external commands, names of
aliases, shell functions and parameters and reserved words as possible
completions. To have the external commands and shell functions listed
separately:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:-command-:*:commands' \
group-name commands
zstyle ':completion:*:*:-command-:*:functions' \
group-name functions
</code></pre>
</div>
<p>As a consequence, any match with the same tag will be displayed in the
same group.</p>
<p>If the name given is the empty string the name of the tag for the
matches will be used as the name of the group. So, to have all different
types of matches displayed separately, one can just set:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' group-name ''
</code></pre>
</div>
<p>All matches for which no group name is defined will be put in a group
named <code>-default-</code>.</p>
<p><span id="index-group_002dorder_002c-completion-style"></span></p>
<p><code>group-order</code></p>
<p>This style is additional to the <code>group-name</code> style to specify the order
for display of the groups defined by that style (compare <code>tag-order</code>,
which determines which completions appear at all). The groups named are
shown in the given order; any other groups are shown in the order
defined by the completion function.</p>
<p>For example, to have names of builtin commands, shell functions and
external commands appear in that order when completing in command
position:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:-command-:*:*' group-order \
builtins functions commands
</code></pre>
</div>
<p><span id="index-groups_002c-completion-style"></span></p>
<p><code>groups</code></p>
<p>A list of names of UNIX groups. If this is not set, group names are
taken from the YP database or the file ‘<code>/etc/group</code>’.</p>
<p><span id="index-hidden_002c-completion-style"></span></p>
<p><code>hidden</code></p>
<p>If this is set to ‘true’, matches for the given context will not be
listed, although any description for the matches set with the <code>format</code>
style will be shown. If it is set to ‘<code>all</code>’, not even the description
will be displayed.</p>
<p>Note that the matches will still be completed; they are just not shown
in the list. To avoid having matches considered as possible completions
at all, the <code>tag-order</code> style can be modified as described below.</p>
<p><span id="index-hosts_002c-completion-style"></span></p>
<p><code>hosts</code></p>
<p>A list of names of hosts that should be completed. If this is not set,
hostnames are taken from the file ‘<code>/etc/hosts</code>’.</p>
<p><span id="index-hosts_002dports_002c-completion-style"></span></p>
<p><code>hosts-ports</code></p>
<p>This style is used by commands that need or accept hostnames and network
ports. The strings in the value should be of the form ‘<code>host``:``port</code>’.
Valid ports are determined by the presence of hostnames; multiple ports
for the same host may appear.</p>
<p><span id="index-ignore_002dline_002c-completion-style"></span></p>
<p><code>ignore-line</code></p>
<p>This is tested for each tag valid for the current completion. If it is
set to ‘true’, none of the words that are already on the line will be
considered as possible completions. If it is set to ‘<code>current</code>’, the
word the cursor is on will not be considered as a possible completion.
The value ‘<code>current-shown</code>’ is similar but only applies if the list of
completions is currently shown on the screen. Finally, if the style is
set to ‘<code>other</code>’, all words on the line except for the current one will
be excluded from the possible completions.</p>
<p>The values ‘<code>current</code>’ and ‘<code>current-shown</code>’ are a bit like the opposite
of the <code>accept-exact</code> style: only strings with missing characters will
be completed.</p>
<p>Note that you almost certainly don’t want to set this to ‘true’ or
‘<code>other</code>’ for a general context such as ‘<code>:completion:*</code>’. This is
because it would disallow completion of, for example, options multiple
times even if the command in question accepts the option more than once.</p>
<p><span id="index-ignore_002dparents_002c-completion-style"></span></p>
<p><code>ignore-parents</code></p>
<p>The style is tested without a tag by the function completing pathnames
in order to determine whether to ignore the names of directories already
mentioned in the current word, or the name of the current working
directory. The value must include one or both of the following strings:</p>
<ul>
<li>
<p><code>parent</code><br />
The name of any directory whose path is already contained in the
word on the line is ignored. For example, when completing after
<code>foo/../</code>, the directory <code>foo</code> will not be considered a valid
completion.</p>
</li>
<li>
<p><code>pwd</code><br />
The name of the current working directory will not be completed;
hence, for example, completion after <code>../</code> will not use the name of
the current directory.</p>
</li>
</ul>
<p>In addition, the value may include one or both of:</p>
<ul>
<li>
<p><code>..</code><br />
Ignore the specified directories only when the word on the line
contains the substring ‘<code>../</code>’.</p>
</li>
<li>
<p><code>directory</code><br />
Ignore the specified directories only when names of directories are
completed, not when completing names of files.</p>
</li>
</ul>
<p>Excluded values act in a similar fashion to values of the
<code>ignored-patterns</code> style, so they can be restored to consideration by
the <code>_ignored</code> completer.</p>
<p><span id="index-extra_002dverbose_002c-completion-style"></span></p>
<p><code>extra-verbose</code></p>
<p>If set, the completion listing is more verbose at the cost of a probable
decrease in completion speed. Completion performance will suffer if this
style is set to ‘true’.</p>
<p><span id="index-ignored_002dpatterns_002c-completion-style"></span></p>
<p><code>ignored-patterns</code></p>
<p>A list of patterns; any trial completion matching one of the patterns
will be excluded from consideration. The <code>_ignored</code> completer can appear
in the list of completers to restore the ignored matches. This is a more
configurable version of the shell parameter <code>$fignore</code>.</p>
<p>Note that the <code>EXTENDED_GLOB</code> option is set during the execution of
completion functions, so the characters ‘<code>#</code>’, ‘<code>~</code>’ and ‘<code>^</code>’ have
special meanings in the patterns.</p>
<p><span id="index-insert_002c-completion-style"></span></p>
<p><code>insert</code></p>
<p>This style is used by the <code>_all_matches</code> completer to decide whether to
insert the list of all matches unconditionally instead of adding the
list as another match.</p>
<p><span id="index-insert_002dids_002c-completion-style"></span></p>
<p><code>insert-ids</code></p>
<p>When completing process IDs, for example as arguments to the <code>kill</code> and
<code>wait</code> builtins the name of a command may be converted to the
appropriate process ID. A problem arises when the process name typed is
not unique. By default (or if this style is set explicitly to ‘<code>menu</code>’)
the name will be converted immediately to a set of possible IDs, and
menu completion will be started to cycle through them.</p>
<p>If the value of the style is ‘<code>single</code>’, the shell will wait until the
user has typed enough to make the command unique before converting the
name to an ID; attempts at completion will be unsuccessful until that
point. If the value is any other string, menu completion will be started
when the string typed by the user is longer than the common prefix to
the corresponding IDs.</p>
<p><span id="index-insert_002dtab_002c-completion-style"></span></p>
<p><code>insert-tab</code></p>
<p>If this is set to ‘true’, the completion system will insert a TAB
character (assuming that was used to start completion) instead of
performing completion when there is no non-blank character to the left
of the cursor. If it is set to ‘false’, completion will be done even
there.</p>
<p>The value may also contain the substrings ‘<code>pending</code>’ or
‘<code>pending=``val</code>’. In this case, the typed character will be inserted
instead of starting completion when there is unprocessed input pending.
If a <code>val</code> is given, completion will not be done if there are at least
that many characters of unprocessed input. This is often useful when
pasting characters into a terminal. Note however, that it relies on the
<code>$PENDING</code> special parameter from the <code>zsh/zle</code> module being set
properly which is not guaranteed on all platforms.</p>
<p>The default value of this style is ‘true’ except for completion within
<code>vared</code> builtin command where it is ‘false’.</p>
<p><span id="index-insert_002dunambiguous_002c-completion-style"></span></p>
<p><code>insert-unambiguous</code></p>
<p>This is used by the <code>_match</code> and <code>_approximate</code> completers. These
completers are often used with menu completion since the word typed may
bear little resemblance to the final completion. However, if this style
is ‘true’, the completer will start menu completion only if it could
find no unambiguous initial string at least as long as the original
string typed by the user.</p>
<p>In the case of the <code>_approximate</code> completer, the completer field in the
context will already have been set to one of <code>correct-``num</code> or
<code>approximate-``num</code>, where <code>num</code> is the number of errors that were
accepted.</p>
<p>In the case of the <code>_match</code> completer, the style may also be set to the
string ‘<code>pattern</code>’. Then the pattern on the line is left unchanged if it
does not match unambiguously.</p>
<p><span id="index-gain_002dprivileges_002c-completion-style"></span></p>
<p><code>gain-privileges</code></p>
<p>If set to <code>true</code>, this style enables the use of commands like <code>sudo</code> or
<code>doas</code> to gain extra privileges when retrieving information for
completion. This is only done when a command such as <code>sudo</code> appears on
the command-line. To force the use of, e.g. <code>sudo</code> or to override any
prefix that might be added due to <code>gain-privileges</code>, the <code>command</code> style
can be used with a value that begins with a hyphen.</p>
<p><span id="index-keep_002dprefix_002c-completion-style"></span></p>
<p><code>keep-prefix</code></p>
<p>This style is used by the <code>_expand</code> completer. If it is ‘true’, the
completer will try to keep a prefix containing a tilde or parameter
expansion. Hence, for example, the string ‘<code>~/f*</code>’ would be expanded to
‘<code>~/foo</code>’ instead of ‘<code>/home/user/foo</code>’. If the style is set to
‘<code>changed</code>’ (the default), the prefix will only be left unchanged if
there were other changes between the expanded words and the original
word from the command line. Any other value forces the prefix to be
expanded unconditionally.</p>
<p>The behaviour of <code>_expand</code> when this style is ‘true’ is to cause
<code>_expand</code> to give up when a single expansion with the restored prefix is
the same as the original; hence any remaining completers may be called.</p>
<p><span id="index-last_002dprompt_002c-completion-style"></span></p>
<p><code>last-prompt</code></p>
<p>This is a more flexible form of the <code>ALWAYS_LAST_PROMPT</code> option. If it
is ‘true’, the completion system will try to return the cursor to the
previous command line after displaying a completion list. It is tested
for all tags valid for the current completion, then the <code>default</code> tag.
The cursor will be moved back to the previous line if this style is
‘true’ for all types of match. Note that unlike the
<code>ALWAYS_LAST_PROMPT</code> option this is independent of the numeric argument.</p>
<p><span id="index-known_002dhosts_002dfiles"></span></p>
<p><code>known-hosts-files</code></p>
<p>This style should contain a list of files to search for host names and
(if the <code>use-ip</code> style is set) IP addresses in a format compatible with
ssh <code>known_hosts</code> files. If it is not set, the files
<code>/etc/ssh/ssh_known_hosts</code> and <code>~/.ssh/known_hosts</code> are used.</p>
<p><span id="index-list_002c-completion-style"></span></p>
<p><code>list</code></p>
<p>This style is used by the <code>_history_complete_word</code> bindable command. If
it is set to ‘true’ it has no effect. If it is set to ‘false’ matches
will not be listed. This overrides the setting of the options
controlling listing behaviour, in particular <code>AUTO_LIST</code>. The context
always starts with ‘<code>:completion:history-words</code>’.</p>
<p><span id="index-list_002dcolors_002c-completion-style"></span></p>
<p><code>list-colors</code></p>
<p>If the <code>zsh/complist</code> module is loaded, this style can be used to set
color specifications. This mechanism replaces the use of the
<code>ZLS_COLORS</code> and <code>ZLS_COLOURS</code> parameters described in <a href="Zsh-Modules.html#The-zsh_002fcomplist-Module">The zsh/complist
Module</a>, but the syntax is
the same.</p>
<p>If this style is set for the <code>default</code> tag, the strings in the value are
taken as specifications that are to be used everywhere. If it is set for
other tags, the specifications are used only for matches of the type
described by the tag. For this to work best, the <code>group-name</code> style must
be set to an empty string.</p>
<p>In addition to setting styles for specific tags, it is also possible to
use group names specified explicitly by the <code>group-name</code> tag together
with the ‘<code>(group)</code>’ syntax allowed by the <code>ZLS_COLORS</code> and
<code>ZLS_COLOURS</code> parameters and simply using the <code>default</code> tag.</p>
<p>It is possible to use any color specifications already set up for the
GNU version of the <code>ls</code> command:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:default' list-colors \
${(s.:.)LS_COLORS}
</code></pre>
</div>
<p>The default colors are the same as for the GNU <code>ls</code> command and can be
obtained by setting the style to an empty string (i.e. <code>’’</code>).</p>
<p><span id="index-list_002ddirs_002dfirst_002c-completion-style"></span></p>
<p><code>list-dirs-first</code></p>
<p>This is used by file completion. If set, directories to be completed are
listed separately from and before completion for other files, regardless
of tag ordering. In addition, the tag <code>other-files</code> is used in place of
<code>all-files</code> for the remaining files, to indicate that no directories are
presented with that tag.</p>
<p><span id="index-list_002dgrouped_002c-completion-style"></span></p>
<p><code>list-grouped</code></p>
<p>If this style is ‘true’ (the default), the completion system will try to
make certain completion listings more compact by grouping matches. For
example, options for commands that have the same description (shown when
the <code>verbose</code> style is set to ‘true’) will appear as a single entry.
However, menu selection can be used to cycle through all the matches.</p>
<p><span id="index-list_002dpacked_002c-completion-style"></span></p>
<p><code>list-packed</code></p>
<p>This is tested for each tag valid in the current context as well as the
<code>default</code> tag. If it is set to ‘true’, the corresponding matches appear
in listings as if the <code>LIST_PACKED</code> option were set. If it is set to
‘false’, they are listed normally.</p>
<p><span id="index-list_002dprompt_002c-completion-style"></span></p>
<p><code>list-prompt</code></p>
<p>If this style is set for the <code>default</code> tag, completion lists that don’t
fit on the screen can be scrolled (see <a href="Zsh-Modules.html#The-zsh_002fcomplist-Module">The zsh/complist
Module</a>). The value, if
not the empty string, will be displayed after every screenful and the
shell will prompt for a key press; if the style is set to the empty
string, a default prompt will be used.</p>
<p>The value may contain the escape sequences: ‘<code>%l</code>’ or ‘<code>%L</code>’, which will
be replaced by the number of the last line displayed and the total
number of lines; ‘<code>%m</code>’ or ‘<code>%M</code>’, the number of the last match shown
and the total number of matches; and ‘<code>%p</code>’ and ‘<code>%P</code>’, ‘<code>Top</code>’ when at
the beginning of the list, ‘<code>Bottom</code>’ when at the end and the position
shown as a percentage of the total length otherwise. In each case the
form with the uppercase letter will be replaced by a string of fixed
width, padded to the right with spaces, while the lowercase form will be
replaced by a variable width string. As in other prompt strings, the
escape sequences ‘<code>%S</code>’, ‘<code>%s</code>’, ‘<code>%B</code>’, ‘<code>%b</code>’, ‘<code>%U</code>’, ‘<code>%u</code>’ for
entering and leaving the display modes standout, bold and underline, and
‘<code>%F</code>’, ‘<code>%f</code>’, ‘<code>%K</code>’, ‘<code>%k</code>’ for changing the foreground background
colour, are also available, as is the form ‘<code>%{</code>...<code>%}</code>’ for enclosing
escape sequences which display with zero (or, with a numeric argument,
some other) width.</p>
<p>After deleting this prompt the variable <code>LISTPROMPT</code> should be unset for
the removal to take effect.</p>
<p><span id="index-list_002drows_002dfirst_002c-completion-style"></span></p>
<p><code>list-rows-first</code></p>
<p>This style is tested in the same way as the <code>list-packed</code> style and
determines whether matches are to be listed in a rows-first fashion as
if the <code>LIST_ROWS_FIRST</code> option were set.</p>
<p><span id="index-list_002dsuffixes_002c-completion-style"></span></p>
<p><code>list-suffixes</code></p>
<p>This style is used by the function that completes filenames. If it is
‘true’, and completion is attempted on a string containing multiple
partially typed pathname components, all ambiguous components will be
shown. Otherwise, completion stops at the first ambiguous component.</p>
<p><span id="index-list_002dseparator_002c-completion-style"></span></p>
<p><code>list-separator</code></p>
<p>The value of this style is used in completion listing to separate the
string to complete from a description when possible (e.g. when
completing options). It defaults to ‘<code>-``-</code>’ (two hyphens).</p>
<p><span id="index-local_002c-completion-style"></span></p>
<p><code>local</code></p>
<p>This is for use with functions that complete URLs for which the
corresponding files are available directly from the file system. Its
value should consist of three strings: a hostname, the path to the
default web pages for the server, and the directory name used by a user
placing web pages within their home area.</p>
<p>For example:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' local toast \
/var/http/public/toast public_html
</code></pre>
</div>
<p>Completion after ‘<code>http://toast/stuff/</code>’ will look for files in the
directory <code>/var/http/public/toast/stuff</code>, while completion after
‘<code>http://toast/~yousir/</code>’ will look for files in the directory
<code>~yousir/public_html</code>.</p>
<p><span id="index-mail_002ddirectory_002c-completion-style"></span></p>
<p><code>mail-directory</code></p>
<p>If set, zsh will assume that mailbox files can be found in the directory
specified. It defaults to ‘<code>~/Mail</code>’.</p>
<p><span id="index-match_002doriginal_002c-completion-style"></span></p>
<p><code>match-original</code></p>
<p>This is used by the <code>_match</code> completer. If it is set to <code>only</code>, <code>_match</code>
will try to generate matches without inserting a ‘<code>*</code>’ at the cursor
position. If set to any other non-empty value, it will first try to
generate matches without inserting the ‘<code>*</code>’ and if that yields no
matches, it will try again with the ‘<code>*</code>’ inserted. If it is unset or
set to the empty string, matching will only be performed with the ‘<code>*</code>’
inserted.</p>
<p><span id="index-matcher_002c-completion-style"></span></p>
<p><code>matcher</code></p>
<p>This style is tested separately for each tag valid in the current
context. Its value is placed before any match specifications given by
the <code>matcher-list</code> style so can override them via the use of an <code>x:</code>
specification. The value should be in the form described in <a href="Completion-Widgets.html#Completion-Matching-Control">Completion
Matching Control</a>.
For examples of this, see the description of the <code>tag-order</code> style.</p>
<p>For notes comparing the use of this and the <code>matcher-list</code> style, see
under the description of the <code>tag-order</code> style.</p>
<p><span id="index-matcher_002dlist_002c-completion-style"></span></p>
<p><code>matcher-list</code></p>
<p>This style can be set to a list of match specifications that are to be
applied everywhere. Match specifications are described in <a href="Completion-Widgets.html#Completion-Matching-Control">Completion
Matching Control</a>.
The completion system will try them one after another for each completer
selected. For example, to try first simple completion and, if that
generates no matches, case-insensitive completion:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'
</code></pre>
</div>
<p>By default each specification replaces the previous one; however, if a
specification is prefixed with <code>+</code>, it is added to the existing list.
Hence it is possible to create increasingly general specifications
without repetition:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' matcher-list \
'' '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'
</code></pre>
</div>
<p>It is possible to create match specifications valid for particular
completers by using the third field of the context. This applies only to
completers that override the global matcher-list, which as of this
writing includes only <code>_prefix</code> and <code>_ignored</code>. For example, to use the
completers <code>_complete</code> and <code>_prefix</code> but allow case-insensitive
completion only with <code>_complete</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer _complete _prefix
zstyle ':completion:*:complete:*:*:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
</code></pre>
</div>
<p>User-defined names, as explained for the <code>completer</code> style, are
available. This makes it possible to try the same completer more than
once with different match specifications each time. For example, to try
normal completion without a match specification, then normal completion
with case-insensitive matching, then correction, and finally
partial-word completion:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer \
_complete _correct _complete:foo
zstyle ':completion:*:complete:*:*:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
zstyle ':completion:*:foo:*:*:*' matcher-list \
'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'
</code></pre>
</div>
<p>If the style is unset in any context no match specification is applied.
Note also that some completers such as <code>_correct</code> and <code>_approximate</code> do
not use the match specifications at all, though these completers will
only ever be called once even if the <code>matcher-list</code> contains more than
one element.</p>
<p>Where multiple specifications are useful, note that the <em>entire</em>
completion is done for each element of <code>matcher-list</code>, which can quickly
reduce the shell’s performance. As a rough rule of thumb, hand, putting
multiple space-separated values into the same string does not have an
appreciable impact on performance.</p>
<p>If there is no current matcher or it is empty, and the option
<code>NO_CASE_GLOB</code> is in effect, the matching for files is performed
case-insensitively in any case. However, any matcher must explicitly
specify case-insensitive matching if that is required.</p>
<p>For notes comparing the use of this and the <code>matcher</code> style, see under
the description of the <code>tag-order</code> style.</p>
<p><span id="index-max_002derrors_002c-completion-style"></span></p>
<p><code>max-errors</code></p>
<p>This is used by the <code>_approximate</code> and <code>_correct</code> completer functions to
determine the maximum number of errors to allow. The completer will try
to generate completions by first allowing one error, then two errors,
and so on, until either a match or matches were found or the maximum
number of errors given by this style has been reached.</p>
<p>If the value for this style contains the string ‘<code>numeric</code>’, the
completer function will take any numeric argument as the maximum number
of errors allowed. For example, with</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:approximate:::' max-errors 2 numeric
</code></pre>
</div>
<p>two errors are allowed if no numeric argument is given, but with a
numeric argument of six (as in ‘<code>ESC-6 TAB</code>’), up to six errors are
accepted. Hence with a value of ‘<code>0 numeric</code>’, no correcting completion
will be attempted unless a numeric argument is given.</p>
<p>If the value contains the string ‘<code>not-numeric</code>’, the completer will
<em>not</em> try to generate corrected completions when given a numeric
argument, so in this case the number given should be greater than zero.
For example, ‘<code>2 not-numeric</code>’ specifies that correcting completion with
two errors will usually be performed, but if a numeric argument is
given, correcting completion will not be performed.</p>
<p>The default value for this style is ‘<code>2 numeric</code>’.</p>
<p><span id="index-max_002dmatches_002dwidth_002c-completion-style"></span></p>
<p><code>max-matches-width</code></p>
<p>This style is used to determine the trade off between the width of the
display used for matches and the width used for their descriptions when
the <code>verbose</code> style is in effect. The value gives the number of display
columns to reserve for the matches. The default is half the width of the
screen.</p>
<p>This has the most impact when several matches have the same description
and so will be grouped together. Increasing the style will allow more
matches to be grouped together; decreasing it will allow more of the
description to be visible.</p>
<p><span id="index-menu_002c-completion-style"></span></p>
<p><code>menu</code></p>
<p>If this is ‘true’ in the context of any of the tags defined for the
current completion menu completion will be used. The value for a
specific tag will take precedence over that for the ‘<code>default</code>’ tag.</p>
<p>If none of the values found in this way is ‘true’ but at least one is
set to ‘<code>auto</code>’, the shell behaves as if the <code>AUTO_MENU</code> option is set.</p>
<p>If one of the values is explicitly set to ‘false’, menu completion will
be explicitly turned off, overriding the <code>MENU_COMPLETE</code> option and
other settings.</p>
<p>In the form ‘<code>yes=``num</code>’, where ‘<code>yes</code>’ may be any of the ‘true’ values
(‘<code>yes</code>’, ‘<code>true</code>’, ‘<code>on</code>’ and ‘<code>1</code>’), menu completion will be turned on
if there are at least <code>num</code> matches. In the form ‘<code>yes=long</code>’, menu
completion will be turned on if the list does not fit on the screen.
This does not activate menu completion if the widget normally only lists
completions, but menu completion can be activated in that case with the
value ‘<code>yes=long-list</code>’ (Typically, the value ‘<code>select=long-list</code>’
described later is more useful as it provides control over scrolling.)</p>
<p>Similarly, with any of the ‘false’ values (as in ‘<code>no=10</code>’), menu
completion will <em>not</em> be used if there are <code>num</code> or more matches.</p>
<p>The value of this widget also controls menu selection, as implemented by
the <code>zsh/complist</code> module. The following values may appear either
alongside or instead of the values above.</p>
<p>If the value contains the string ‘<code>select</code>’, menu selection will be
started unconditionally.</p>
<p>In the form ‘<code>select=``num</code>’, menu selection will only be started if
there are at least <code>num</code> matches. If the values for more than one tag
provide a number, the smallest number is taken.</p>
<p>Menu selection can be turned off explicitly by defining a value
containing the string‘<code>no-select</code>’.</p>
<p>It is also possible to start menu selection only if the list of matches
does not fit on the screen by using the value ‘<code>select=long</code>’. To start
menu selection even if the current widget only performs listing, use the
value ‘<code>select=long-list</code>’.</p>
<p>To turn on menu completion or menu selection when there are a certain
number of matches <em>or</em> the list of matches does not fit on the screen,
both of ‘<code>yes=</code>’ and ‘<code>select=</code>’ may be given twice, once with a number
and once with ‘<code>long</code>’ or ‘<code>long-list</code>’.</p>
<p>Finally, it is possible to activate two special modes of menu selection.
The word ‘<code>interactive</code>’ in the value causes interactive mode to be
entered immediately when menu selection is started; see <a href="Zsh-Modules.html#The-zsh_002fcomplist-Module">The
zsh/complist Module</a> for a
description of interactive mode. Including the string ‘<code>search</code>’ does
the same for incremental search mode. To select backward incremental
search, include the string ‘<code>search-backward</code>’.</p>
<p><span id="index-muttrc_002c-completion-style"></span></p>
<p><code>muttrc</code></p>
<p>If set, gives the location of the mutt configuration file. It defaults
to ‘<code>~/.muttrc</code>’.</p>
<p><span id="index-numbers_002c-completion-style"></span></p>
<p><code>numbers</code></p>
<p>This is used with the <code>jobs</code> tag. If it is ‘true’, the shell will
complete job numbers instead of the shortest unambiguous prefix of the
job command text. If the value is a number, job numbers will only be
used if that many words from the job descriptions are required to
resolve ambiguities. For example, if the value is ‘<code>1</code>’, strings will
only be used if all jobs differ in the first word on their command
lines.</p>
<p><span id="index-old_002dlist_002c-completion-style"></span></p>
<p><code>old-list</code></p>
<p>This is used by the <code>_oldlist</code> completer. If it is set to ‘<code>always</code>’,
then standard widgets which perform listing will retain the current list
of matches, however they were generated; this can be turned off
explicitly with the value ‘<code>never</code>’, giving the behaviour without the
<code>_oldlist</code> completer. If the style is unset, or any other value, then
the existing list of completions is displayed if it is not already;
otherwise, the standard completion list is generated; this is the
default behaviour of <code>_oldlist</code>. However, if there is an old list and
this style contains the name of the completer function that generated
the list, then the old list will be used even if it was generated by a
widget which does not do listing.</p>
<p>For example, suppose you type <code>^Xc</code> to use the <code>_correct_word</code> widget,
which generates a list of corrections for the word under the cursor.
Usually, typing <code>^D</code> would generate a standard list of completions for
the word on the command line, and show that. With <code>_oldlist</code>, it will
instead show the list of corrections already generated.</p>
<p>As another example consider the <code>_match</code> completer: with the
<code>insert-unambiguous</code> style set to ‘true’ it inserts only a common prefix
string, if there is any. However, this may remove parts of the original
pattern, so that further completion could produce more matches than on
the first attempt. By using the <code>_oldlist</code> completer and setting this
style to <code>_match</code>, the list of matches generated on the first attempt
will be used again.</p>
<p><span id="index-old_002dmatches_002c-completion-style"></span></p>
<p><code>old-matches</code></p>
<p>This is used by the <code>_all_matches</code> completer to decide if an old list of
matches should be used if one exists. This is selected by one of the
‘true’ values or by the string ‘<code>only</code>’. If the value is ‘<code>only</code>’,
<code>_all_matches</code> will only use an old list and won’t have any effect on
the list of matches currently being generated.</p>
<p>If this style is set it is generally unwise to call the <code>_all_matches</code>
completer unconditionally. One possible use is for either this style or
the <code>completer</code> style to be defined with the <code>-e</code> option to <code>zstyle</code> to
make the style conditional.</p>
<p><span id="index-old_002dmenu_002c-completion-style"></span></p>
<p><code>old-menu</code></p>
<p>This is used by the <code>_oldlist</code> completer. It controls how menu
completion behaves when a completion has already been inserted and the
user types a standard completion key such as <code>TAB</code>. The default
behaviour of <code>_oldlist</code> is that menu completion always continues with
the existing list of completions. If this style is set to ‘false’,
however, a new completion is started if the old list was generated by a
different completion command; this is the behaviour without the
<code>_oldlist</code> completer.</p>
<p>For example, suppose you type <code>^Xc</code> to generate a list of corrections,
and menu completion is started in one of the usual ways. Usually, or
with this style set to ‘false’, typing <code>TAB</code> at this point would start
trying to complete the line as it now appears. With <code>_oldlist</code>, it
instead continues to cycle through the list of corrections.</p>
<p><span id="index-original_002c-completion-style"></span></p>
<p><code>original</code></p>
<p>This is used by the <code>_approximate</code> and <code>_correct</code> completers to decide
if the original string should be added as a possible completion.
Normally, this is done only if there are at least two possible
corrections, but if this style is set to ‘true’, it is always added.
Note that the style will be examined with the completer field in the
context name set to <code>correct-``num</code> or <code>approximate-``num</code>, where <code>num</code>
is the number of errors that were accepted.</p>
<p><span id="index-packageset_002c-completion-style"></span></p>
<p><code>packageset</code></p>
<p>This style is used when completing arguments of the Debian ‘<code>dpkg</code>’
program. It contains an override for the default package set for a given
context. For example,</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:complete:dpkg:option--status-1:*' \
packageset avail
</code></pre>
</div>
<p>causes available packages, rather than only installed packages, to be
completed for ‘<code>dpkg -``-status</code>’.</p>
<p><span id="index-path_002c-completion-style"></span></p>
<p><code>path</code></p>
<p>The function that completes color names uses this style with the
<code>colors</code> tag. The value should be the pathname of a file containing
color names in the format of an X11 <code>rgb.txt</code> file. If the style is not
set but this file is found in one of various standard locations it will
be used as the default.</p>
<p><span id="index-path_002dcompletion_002c-completion-style"></span></p>
<p><code>path-completion</code></p>
<p>This is used by filename completion. By default, filename completion
examines all components of a path to see if there are completions of
that component. For example, <code>/u/b/z</code> can be completed to
<code>/usr/bin/zsh</code>. Explicitly setting this style to ‘false’ inhibits this
behaviour for path components up to the <code>/</code> before the cursor; this
overrides the setting of <code>accept-exact-dirs</code>.</p>
<p>Even with the style set to ‘false’, it is still possible to complete
multiple paths by setting the option <code>COMPLETE_IN_WORD</code> and moving the
cursor back to the first component in the path to be completed. For
example, <code>/u/b/z</code> can be completed to <code>/usr/bin/zsh</code> if the cursor is
after the <code>/u</code>.</p>
<p><span id="index-pine_002ddirectory_002c-completion-style"></span></p>
<p><code>pine-directory</code></p>
<p>If set, specifies the directory containing PINE mailbox files. There is
no default, since recursively searching this directory is inconvenient
for anyone who doesn’t use PINE.</p>
<p><span id="index-ports_002c-completion-style"></span></p>
<p><code>ports</code></p>
<p>A list of Internet service names (network ports) to complete. If this is
not set, service names are taken from the file ‘<code>/etc/services</code>’.</p>
<p><span id="index-prefix_002dhidden_002c-completion-style"></span></p>
<p><code>prefix-hidden</code></p>
<p>This is used for certain completions which share a common prefix, for
example command options beginning with dashes. If it is ‘true’, the
prefix will not be shown in the list of matches.</p>
<p>The default value for this style is ‘false’.</p>
<p><span id="index-prefix_002dneeded_002c-completion-style"></span></p>
<p><code>prefix-needed</code></p>
<p>This style is also relevant for matches with a common prefix. If it is
set to ‘true’ this common prefix must be typed by the user to generate
the matches.</p>
<p>The style is applicable to the <code>options</code>, <code>signals</code>, <code>jobs</code>,
<code>functions</code>, and <code>parameters</code> completion tags.</p>
<p>For command options, this means that the initial ‘<code>-</code>’, ‘<code>+</code>’, or
‘<code>-``-</code>’ must be typed explicitly before option names will be
completed.</p>
<p>For signals, an initial ‘<code>-</code>’ is required before signal names will be
completed.</p>
<p>For jobs, an initial ‘<code>%</code>’ is required before job names will be
completed.</p>
<p>For function and parameter names, an initial ‘<code>_</code>’ or ‘<code>.</code>’ is required
before function or parameter names starting with those characters will
be completed.</p>
<p>The default value for this style is ‘false’ for <code>function</code> and
<code>parameter</code> completions, and ‘true’ otherwise.</p>
<p><span id="index-preserve_002dprefix_002c-completion-style"></span></p>
<p><code>preserve-prefix</code></p>
<p>This style is used when completing path names. Its value should be a
pattern matching an initial prefix of the word to complete that should
be left unchanged under all circumstances. For example, on some Unices
an initial ‘<code>//</code>’ (double slash) has a special meaning; setting this
style to the string ‘<code>//</code>’ will preserve it. As another example, setting
this style to ‘<code>?:/</code>’ under Cygwin would allow completion after
‘<code>a:/...</code>’ and so on.</p>
<p><span id="index-range_002c-completion-style"></span></p>
<p><code>range</code></p>
<p>This is used by the <code>_history</code> completer and the
<code>_history_complete_word</code> bindable command to decide which words should
be completed.</p>
<p>If it is a single number, only the last <code>N</code> words from the history will
be completed.</p>
<p>If it is a range of the form ‘<code>max``:``slice</code>’, the last <code>slice</code> words
will be completed; then if that yields no matches, the <code>slice</code> words
before those will be tried and so on. This process stops either when at
least one match has been found, or <code>max</code> words have been tried.</p>
<p>The default is to complete all words from the history at once.</p>
<p><span id="index-recursive_002dfiles_002c-completion-style"></span></p>
<p><code>recursive-files</code></p>
<p>If this style is set, its value is an array of patterns to be tested
against ‘<code>$PWD/</code>’: note the trailing slash, which allows directories in
the pattern to be delimited unambiguously by including slashes on both
sides. If an ordinary file completion fails and the word on the command
line does not yet have a directory part to its name, the style is
retrieved using the same tag as for the completion just attempted, then
the elements tested against <code>$PWD/</code> in turn. If one matches, then the
shell reattempts completion by prepending the word on the command line
with each directory in the expansion of <code>**/*(/)</code> in turn. Typically the
elements of the style will be set to restrict the number of directories
beneath the current one to a manageable number, for example
‘<code>*/.git/*</code>’.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' recursive-files '*/zsh/*'
</code></pre>
</div>
<p>If the current directory is <code>/home/pws/zsh/Src</code>, then <code>zle_tr</code><em>TAB</em> can
be completed to <code>Zle/zle_tricky.c</code>.</p>
<p><span id="index-regular_002c-completion-style"></span></p>
<p><code>regular</code></p>
<p>This style is used by the <code>_expand_alias</code> completer and bindable
command. If set to ‘true’ (the default), regular aliases will be
expanded but only in command position. If it is set to ‘false’, regular
aliases will never be expanded. If it is set to ‘<code>always</code>’, regular
aliases will be expanded even if not in command position.</p>
<p><span id="index-rehash_002c-completion-style"></span></p>
<p><code>rehash</code></p>
<p>If this is set when completing external commands, the internal list
(hash) of commands will be updated for each search by issuing the
<code>rehash</code> command. There is a speed penalty for this which is only likely
to be noticeable when directories in the path have slow file access.</p>
<p><span id="index-remote_002daccess_002c-completion-style"></span></p>
<p><code>remote-access</code></p>
<p>If set to ‘false’, certain commands will be prevented from making
Internet connections to retrieve remote information. This includes the
completion for the <code>CVS</code> command.</p>
<p>It is not always possible to know if connections are in fact to a remote
site, so some may be prevented unnecessarily.</p>
<p><span id="index-remove_002dall_002ddups_002c-completion-style"></span></p>
<p><code>remove-all-dups</code></p>
<p>The <code>_history_complete_word</code> bindable command and the <code>_history</code>
completer use this to decide if all duplicate matches should be removed,
rather than just consecutive duplicates.</p>
<p><span id="index-select_002dprompt_002c-completion-style"></span></p>
<p><code>select-prompt</code></p>
<p>If this is set for the <code>default</code> tag, its value will be displayed during
menu selection (see the <code>menu</code> style above) when the completion list
does not fit on the screen as a whole. The same escapes as for the
<code>list-prompt</code> style are understood, except that the numbers refer to the
match or line the mark is on. A default prompt is used when the value is
the empty string.</p>
<p><span id="index-select_002dscroll_002c-completion-style"></span></p>
<p><code>select-scroll</code></p>
<p>This style is tested for the <code>default</code> tag and determines how a
completion list is scrolled during a menu selection (see the <code>menu</code>
style above) when the completion list does not fit on the screen as a
whole. If the value is ‘<code>0</code>’ (zero), the list is scrolled by
half-screenfuls; if it is a positive integer, the list is scrolled by
the given number of lines; if it is a negative number, the list is
scrolled by a screenful minus the absolute value of the given number of
lines. The default is to scroll by single lines.</p>
<p><span id="index-separate_002dsections_002c-completion-style"></span></p>
<p><code>separate-sections</code></p>
<p>This style is used with the <code>manuals</code> tag when completing names of
manual pages. If it is ‘true’, entries for different sections are added
separately using tag names of the form ‘<code>manual.``X</code>’, where <code>X</code> is the
section number. When the <code>group-name</code> style is also in effect, pages
from different sections will appear separately. This style is also used
similarly with the <code>words</code> style when completing words for the dict
command. It allows words from different dictionary databases to be added
separately. The default for this style is ‘false’.</p>
<p><span id="index-show_002dambiguity_002c-completion-style"></span></p>
<p><code>show-ambiguity</code></p>
<p>If the <code>zsh/complist</code> module is loaded, this style can be used to
highlight the first ambiguous character in completion lists. The value
is either a color indication such as those supported by the
<code>list-colors</code> style or, with a value of ‘true’, a default of underlining
is selected. The highlighting is only applied if the completion display
strings correspond to the actual matches.</p>
<p><span id="index-show_002dcompleter_002c-completion-style"></span></p>
<p><code>show-completer</code></p>
<p>Tested whenever a new completer is tried. If it is ‘true’, the
completion system outputs a progress message in the listing area showing
what completer is being tried. The message will be overwritten by any
output when completions are found and is removed after completion is
finished.</p>
<p><span id="index-single_002dignored_002c-completion-style"></span></p>
<p><code>single-ignored</code></p>
<p>This is used by the <code>_ignored</code> completer when there is only one match.
If its value is ‘<code>show</code>’, the single match will be displayed but not
inserted. If the value is ‘<code>menu</code>’, then the single match and the
original string are both added as matches and menu completion is
started, making it easy to select either of them.</p>
<p><span id="index-sort_002c-completion-style"></span></p>
<p><code>sort</code></p>
<p>This allows the standard ordering of matches to be overridden.</p>
<p>If its value is ‘<code>true</code>’ or ‘<code>false</code>’, sorting is enabled or disabled.
Additionally the values associated with the ‘<code>-o</code>’ option to <code>compadd</code>
can also be listed: <code>match</code>, <code>nosort</code>, <code>numeric</code>, <code>reverse</code>. If it is
not set for the context, the standard behaviour of the calling widget is
used.</p>
<p>The style is tested first against the full context including the tag,
and if that fails to produce a value against the context without the
tag.</p>
<p>In many cases where a calling widget explicitly selects a particular
ordering in lieu of the default, a value of ‘<code>true</code>’ is not honoured. An
example of where this is not the case is for command history where the
default of sorting matches chronologically may be overridden by setting
the style to ‘true’.</p>
<p>In the <code>_expand</code> completer, if it is set to ‘true’, the expansions
generated will always be sorted. If it is set to ‘<code>menu</code>’, then the
expansions are only sorted when they are offered as single strings but
not in the string containing all possible expansions.</p>
<p><span id="index-special_002ddirs_002c-completion-style"></span></p>
<p><code>special-dirs</code></p>
<p>Normally, the completion code will not produce the directory names ‘<code>.</code>’
and ‘<code>..</code>’ as possible completions. If this style is set to ‘true’, it
will add both ‘<code>.</code>’ and ‘<code>..</code>’ as possible completions; if it is set to
‘<code>..</code>’, only ‘<code>..</code>’ will be added.</p>
<p>The following example sets <code>special-dirs</code> to ‘<code>..</code>’ when the current
prefix is empty, is a single ‘<code>.</code>’, or consists only of a path beginning
with ‘<code>../</code>’. Otherwise the value is ‘false’.</p>
<div class="example">
<pre><code class="language-example">zstyle -e ':completion:*' special-dirs \
'[[ $PREFIX = (../)#(|.|..) ]] &amp;&amp; reply=(..)'
</code></pre>
</div>
<p><span id="index-squeeze_002dslashes_002c-completion-style"></span></p>
<p><code>squeeze-slashes</code></p>
<p>If set to ‘true’, sequences of slashes in filename paths (for example in
‘<code>foo//bar</code>’) will be treated as a single slash. This is the usual
behaviour of UNIX paths. However, by default the file completion
function behaves as if there were a ‘<code>*</code>’ between the slashes.</p>
<p><span id="index-stop_002c-completion-style"></span></p>
<p><code>stop</code></p>
<p>If set to ‘true’, the <code>_history_complete_word</code> bindable command will
stop once when reaching the beginning or end of the history. Invoking
<code>_history_complete_word</code> will then wrap around to the opposite end of
the history. If this style is set to ‘false’ (the default),
<code>_history_complete_word</code> will loop immediately as in a menu completion.</p>
<p><span id="index-strip_002dcomments_002c-completion-style"></span></p>
<p><code>strip-comments</code></p>
<p>If set to ‘true’, this style causes non-essential comment text to be
removed from completion matches. Currently it is only used when
completing e-mail addresses where it removes any display name from the
addresses, cutting them down to plain <code>user@host</code> form.</p>
<p><span id="index-subst_002dglobs_002donly_002c-completion-style"></span></p>
<p><code>subst-globs-only</code></p>
<p>This is used by the <code>_expand</code> completer. If it is set to ‘true’, the
expansion will only be used if it resulted from globbing; hence, if
expansions resulted from the use of the <code>substitute</code> style described
below, but these were not further changed by globbing, the expansions
will be rejected.</p>
<p>The default for this style is ‘false’.</p>
<p><span id="index-substitute_002c-completion-style"></span></p>
<p><code>substitute</code></p>
<p>This boolean style controls whether the <code>_expand</code> completer will first
try to expand all substitutions in the string (such as ‘<code>$(``...``)</code>’
and ‘<code>${``...``}</code>’).</p>
<p>The default is ‘true’.</p>
<p><span id="index-suffix_002c-completion-style"></span></p>
<p><code>suffix</code></p>
<p>This is used by the <code>_expand</code> completer if the word starts with a tilde
or contains a parameter expansion. If it is set to ‘true’, the word will
only be expanded if it doesn’t have a suffix, i.e. if it is something
like ‘<code>~foo</code>’ or ‘<code>$foo</code>’ rather than ‘<code>~foo/</code>’ or ‘<code>$foo/bar</code>’, unless
that suffix itself contains characters eligible for expansion. The
default for this style is ‘true’.</p>
<p><span id="index-tag_002dorder_002c-completion-style"></span></p>
<p><code>tag-order</code></p>
<p>This provides a mechanism for sorting how the tags available in a
particular context will be used.</p>
<p>The values for the style are sets of space-separated lists of tags. The
tags in each value will be tried at the same time; if no match is found,
the next value is used. (See the <code>file-patterns</code> style for an exception
to this behavior.)</p>
<p>For example:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:complete:-command-:*:*' tag-order \
'commands functions'
</code></pre>
</div>
<p>specifies that completion in command position first offers external
commands and shell functions. Remaining tags will be tried if no
completions are found.</p>
<p>In addition to tag names, each string in the value may take one of the
following forms:</p>
<ul>
<li>
<p><code>-</code><br />
If any value consists of only a hyphen, then <em>only</em> the tags
specified in the other values are generated. Normally all tags not
explicitly selected are tried last if the specified tags fail to
generate any matches. This means that a single value consisting only
of a single hyphen turns off completion.</p>
</li>
<li>
<p><code>!</code> <code>tags</code>...<br />
A string starting with an exclamation mark specifies names of tags
that are <em>not</em> to be used. The effect is the same as if all other
possible tags for the context had been listed.</p>
</li>
<li>
<p><code>tag``:``label</code> ...<br />
Here, <code>tag</code> is one of the standard tags and <code>label</code> is an arbitrary
name. Matches are generated as normal but the name <code>label</code> is used
in contexts instead of <code>tag</code>. This is not useful in words starting
with <code>!</code>.</p>
<p>If the <code>label</code> starts with a hyphen, the <code>tag</code> is prepended to the
<code>label</code> to form the name used for lookup. This can be used to make
the completion system try a certain tag more than once, supplying
different style settings for each attempt; see below for an example.</p>
</li>
<li>
<p><code>tag``:``label``:``description</code><br />
As before, but <code>description</code> will replace the ‘<code>%d</code>’ in the value of
the <code>format</code> style instead of the default description supplied by
the completion function. Spaces in the description must be quoted
with a backslash. A ‘<code>%d</code>’ appearing in <code>description</code> is replaced
with the description given by the completion function.</p>
</li>
</ul>
<p>In any of the forms above the tag may be a pattern or several patterns
in the form ‘<code>{``pat1``,``pat2...``}</code>’. In this case all matching tags
will be used except for any given explicitly in the same string.</p>
<p>One use of these features is to try one tag more than once, setting
other styles differently on each attempt, but still to use all the other
tags without having to repeat them all. For example, to make completion
of function names in command position ignore all the completion
functions starting with an underscore the first time completion is
tried:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:-command-:*:*' tag-order \
'functions:-non-comp *' functions
zstyle ':completion:*:functions-non-comp' \
ignored-patterns '_*'
</code></pre>
</div>
<p>On the first attempt, all tags will be offered but the <code>functions</code> tag
will be replaced by <code>functions-non-comp</code>. The <code>ignored-patterns</code> style
is set for this tag to exclude functions starting with an underscore. If
there are no matches, the second value of the <code>tag-order</code> style is used
which completes functions using the default tag, this time presumably
including all function names.</p>
<p>The matches for one tag can be split into different groups. For example:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' tag-order \
'options:-long:long\ options
options:-short:short\ options
options:-single-letter:single\ letter\ options'
zstyle ':completion:*:options-long' \
ignored-patterns '[-+](|-|[^-]*)'
zstyle ':completion:*:options-short' \
ignored-patterns '--*' '[-+]?'
zstyle ':completion:*:options-single-letter' \
ignored-patterns '???*'
</code></pre>
</div>
<p>With the <code>group-names</code> style set, options beginning with ‘<code>-``-</code>’,
options beginning with a single ‘<code>-</code>’ or ‘<code>+</code>’ but containing multiple
characters, and single-letter options will be displayed in separate
groups with different descriptions.</p>
<p>Another use of patterns is to try multiple match specifications one
after another. The <code>matcher-list</code> style offers something similar, but it
is tested very early in the completion system and hence can’t be set for
single commands nor for more specific contexts. Here is how to try
normal completion without any match specification and, if that generates
no matches, try again with case-insensitive matching, restricting the
effect to arguments of the command <code>foo</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:foo:*:*' tag-order '*' '*:-case'
zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'
</code></pre>
</div>
<p>First, all the tags offered when completing after <code>foo</code> are tried using
the normal tag name. If that generates no matches, the second value of
<code>tag-order</code> is used, which tries all tags again except that this time
each has <code>-case</code> appended to its name for lookup of styles. Hence this
time the value for the <code>matcher</code> style from the second call to <code>zstyle</code>
in the example is used to make completion case-insensitive.</p>
<p>It is possible to use the <code>-e</code> option of the <code>zstyle</code> builtin command to
specify conditions for the use of particular tags. For example:</p>
<div class="example">
<pre><code class="language-example">zstyle -e '*:-command-:*' tag-order '
if [[ -n $PREFIX$SUFFIX ]]; then
reply=( )
else
reply=( - )
fi'
</code></pre>
</div>
<p>Completion in command position will be attempted only if the string
typed so far is not empty. This is tested using the <code>PREFIX</code> special
parameter; see <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a> for a description
of parameters which are special inside completion widgets. Setting
<code>reply</code> to an empty array provides the default behaviour of trying all
tags at once; setting it to an array containing only a hyphen disables
the use of all tags and hence of all completions.</p>
<p>If no <code>tag-order</code> style has been defined for a context, the strings
‘<code>(|*-)argument-* (|*-)option-* values</code>’ and ‘<code>options</code>’ plus all tags
offered by the completion function will be used to provide a sensible
default behavior that causes arguments (whether normal command arguments
or arguments of options) to be completed before option names for most
commands.</p>
<p><span id="index-urls_002c-completion-style"></span></p>
<p><code>urls</code></p>
<p>This is used together with the <code>urls</code> tag by functions completing URLs.</p>
<p>If the value consists of more than one string, or if the only string
does not name a file or directory, the strings are used as the URLs to
complete.</p>
<p>If the value contains only one string which is the name of a normal file
the URLs are taken from that file (where the URLs may be separated by
white space or newlines).</p>
<p>Finally, if the only string in the value names a directory, the
directory hierarchy rooted at this directory gives the completions. The
top level directory should be the file access method, such as ‘<code>http</code>’,
‘<code>ftp</code>’, ‘<code>bookmark</code>’ and so on. In many cases the next level of
directories will be a filename. The directory hierarchy can descend as
deep as necessary.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' urls ~/.urls
mkdir -p ~/.urls/ftp/ftp.zsh.org/pub
</code></pre>
</div>
<p>allows completion of all the components of the URL ‘<code>netscape</code>’ or
‘<code>lynx</code>’. Note, however, that access methods and files are completed
separately, so if the <code>hosts</code> style is set hosts can be completed
without reference to the <code>urls</code> style.</p>
<p>See the description in the function <code>_urls</code> itself for more information
(e.g. ‘<code>more $^fpath/_urls(N)</code>’).</p>
<p><span id="index-use_002dcache_002c-completion-style"></span></p>
<p><code>use-cache</code></p>
<p>If this is set, the completion caching layer is activated for any
completions which use it (via the <code>_store_cache</code>, <code>_retrieve_cache</code>, and
<code>_cache_invalid</code> functions). The directory containing the cache files
can be changed with the <code>cache-path</code> style.</p>
<p><span id="index-use_002dcompctl_002c-completion-style"></span></p>
<p><code>use-compctl</code></p>
<p>If this style is set to a string <em>not</em> equal to <code>false</code>, <code>0</code>, <code>no</code>, and
<code>off</code>, the completion system may use any completion specifications
defined with the <code>compctl</code> builtin command. If the style is unset, this
is done only if the <code>zsh/compctl</code> module is loaded. The string may also
contain the substring ‘<code>first</code>’ to use completions defined with
‘<code>compctl -T</code>’, and the substring ‘<code>default</code>’ to use the completion
defined with ‘<code>compctl -D</code>’.</p>
<p>Note that this is only intended to smooth the transition from <code>compctl</code>
to the new completion system and may disappear in the future.</p>
<p>Note also that the definitions from <code>compctl</code> will only be used if there
is no specific completion function for the command in question. For
example, if there is a function <code>_foo</code> to complete arguments to the
command <code>foo</code>, <code>compctl</code> will never be invoked for <code>foo</code>. However, the
<code>compctl</code> version will be tried if <code>foo</code> only uses default completion.</p>
<p><span id="index-use_002dip_002c-completion-style"></span></p>
<p><code>use-ip</code></p>
<p>By default, the function <code>_hosts</code> that completes host names strips IP
addresses from entries read from host databases such as NIS and ssh
files. If this style is ‘true’, the corresponding IP addresses can be
completed as well. This style is not use in any context where the
<code>hosts</code> style is set; note also it must be set before the cache of host
names is generated (typically the first completion attempt).</p>
<p><span id="index-users_002c-completion-style"></span></p>
<p><code>users</code></p>
<p>This may be set to a list of usernames to be completed. If it is not set
all usernames will be completed. Note that if it is set only that list
of users will be completed; this is because on some systems querying all
users can take a prohibitive amount of time.</p>
<p><span id="index-users_002dhosts_002c-completion-style"></span></p>
<p><code>users-hosts</code></p>
<p>The values of this style should be of the form ‘<code>user``@``host</code>’ or
‘<code>user``:``host</code>’. It is used for commands that need pairs of user-
and hostnames. These commands will complete usernames from this style
(only), and will restrict subsequent hostname completion to hosts paired
with that user in one of the values of the style.</p>
<p>It is possible to group values for sets of commands which allow a remote
login, such as <code>rlogin</code> and <code>ssh</code>, by using the <code>my-accounts</code> tag.
Similarly, values for sets of commands which usually refer to the
accounts of other people, such as <code>talk</code> and <code>finger</code>, can be grouped by
using the <code>other-accounts</code> tag. More ambivalent commands may use the
<code>accounts</code> tag.</p>
<p><span id="index-users_002dhosts_002dports_002c-completion-style"></span></p>
<p><code>users-hosts-ports</code></p>
<p>Like <code>users-hosts</code> but used for commands like <code>telnet</code> and containing
strings of the form ‘<code>user``@``host``:``port</code>’.</p>
<p><span id="index-verbose_002c-completion-style"></span></p>
<p><code>verbose</code></p>
<p>If set, as it is by default, the completion listing is more verbose. In
particular many commands show descriptions for options if this style is
‘true’.</p>
<p><span id="index-word_002c-completion-style"></span></p>
<p><code>word</code></p>
<p>This is used by the <code>_list</code> completer, which prevents the insertion of
completions until a second completion attempt when the line has not
changed. The normal way of finding out if the line has changed is to
compare its entire contents between the two occasions. If this style is
‘true’, the comparison is instead performed only on the current word.
Hence if completion is performed on another word with the same contents,
completion will not be delayed.</p>
<hr />
<p><span id="Control-Functions"></span>
<span id="Control-Functions-1"></span></p>
<h2 id="204-control-functions"><a class="header" href="#204-control-functions">20.4 Control Functions</a></h2>
<p><span id="index-completion-system_002c-choosing-completers"></span></p>
<p>The initialization script <code>compinit</code> redefines all the widgets which
perform completion to call the supplied widget function
<code>_main_complete</code>. This function acts as a wrapper calling the so-called
‘completer’ functions that generate matches. If <code>_main_complete</code> is
called with arguments, these are taken as the names of completer
functions to be called in the order given. If no arguments are given,
the set of functions to try is taken from the <code>completer</code> style. For
example, to use normal completion and correction if that doesn’t
generate any matches:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer _complete _correct
</code></pre>
</div>
<p>after calling <code>compinit</code>. The default value for this style is
‘<code>_complete _ignored</code>’, i.e. normally only ordinary completion is
tried, first with the effect of the <code>ignored-patterns</code> style and then
without it. The <code>_main_complete</code> function uses the return status of the
completer functions to decide if other completers should be called. If
the return status is zero, no other completers are tried and the
<code>_main_complete</code> function returns.</p>
<p>If the first argument to <code>_main_complete</code> is a single hyphen, the
arguments will not be taken as names of completers. Instead, the second
argument gives a name to use in the <code>completer</code> field of the context and
the other arguments give a command name and arguments to call to
generate the matches.</p>
<p>The following completer functions are contained in the distribution,
although users may write their own. Note that in contexts the leading
underscore is stripped, for example basic completion is performed in the
context ‘<code>:completion::complete:``...</code>’.</p>
<p><span id="index-completion-system_002c-completers"></span></p>
<p><span id="index-_005fall_005fmatches"></span></p>
<p><code>_all_matches</code></p>
<p>This completer can be used to add a string consisting of all other
matches. As it influences later completers it must appear as the first
completer in the list. The list of all matches is affected by the
<code>avoid-completer</code> and <code>old-matches</code> styles described above.</p>
<p>It may be useful to use the <code>_generic</code> function described below to bind
<code>_all_matches</code> to its own keystroke, for example:</p>
<div class="example">
<pre><code class="language-example">zle -C all-matches complete-word _generic
bindkey '^Xa' all-matches
zstyle ':completion:all-matches:*' old-matches only
zstyle ':completion:all-matches::::' completer _all_matches
</code></pre>
</div>
<p>Note that this does not generate completions by itself: first use any of
the standard ways of generating a list of completions, then use <code>^Xa</code> to
show all matches. It is possible instead to add a standard completer to
the list and request that the list of all matches should be directly
inserted:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:all-matches::::' completer \
_all_matches _complete
zstyle ':completion:all-matches:*' insert true
</code></pre>
</div>
<p>In this case the <code>old-matches</code> style should not be set.</p>
<p><span id="index-_005fapproximate"></span></p>
<p><code>_approximate</code></p>
<p>This is similar to the basic <code>_complete</code> completer but allows the
completions to undergo corrections. The maximum number of errors can be
specified by the <code>max-errors</code> style; see the description of approximate
matching in <a href="Expansion.html#Filename-Generation">Filename Generation</a>
for how errors are counted. Normally this completer will only be tried
after the normal <code>_complete</code> completer:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer _complete _approximate
</code></pre>
</div>
<p>This will give correcting completion if and only if normal completion
yields no possible completions. When corrected completions are found,
the completer will normally start menu completion allowing you to cycle
through these strings.</p>
<p>This completer uses the tags <code>corrections</code> and <code>original</code> when
generating the possible corrections and the original string. The
<code>format</code> style for the former may contain the additional sequences
‘<code>%e</code>’ and ‘<code>%o</code>’ which will be replaced by the number of errors
accepted to generate the corrections and the original string,
respectively.</p>
<p>The completer progressively increases the number of errors allowed up to
the limit by the <code>max-errors</code> style, hence if a completion is found with
one error, no completions with two errors will be shown, and so on. It
modifies the completer name in the context to indicate the number of
errors being tried: on the first try the completer field contains
‘<code>approximate-1</code>’, on the second try ‘<code>approximate-2</code>’, and so on.</p>
<p>When <code>_approximate</code> is called from another function, the number of
errors to accept may be passed with the <code>-a</code> option. The argument is in
the same format as the <code>max-errors</code> style, all in one string.</p>
<p>Note that this completer (and the <code>_correct</code> completer mentioned below)
can be quite expensive to call, especially when a large number of errors
are allowed. One way to avoid this is to set up the <code>completer</code> style
using the <code>-e</code> option to zstyle so that some completers are only used
when completion is attempted a second time on the same string, e.g.:</p>
<div class="example">
<pre><code class="language-example">zstyle -e ':completion:*' completer '
if [[ $_last_try != &quot;$HISTNO$BUFFER$CURSOR&quot; ]]; then
_last_try=&quot;$HISTNO$BUFFER$CURSOR&quot;
reply=(_complete _match _prefix)
else
reply=(_ignored _correct _approximate)
fi'
</code></pre>
</div>
<p>This uses the <code>HISTNO</code> parameter and the <code>BUFFER</code> and <code>CURSOR</code> special
parameters that are available inside zle and completion widgets to find
out if the command line hasn’t changed since the last time completion
was tried. Only then are the <code>_ignored</code>, <code>_correct</code> and <code>_approximate</code>
completers called.</p>
<p><span id="index-_005fcanonical_005fpaths"></span></p>
<p><code>_canonical_paths</code> [ <code>-A</code> <code>var</code> ] [ <code>-N</code> ] [ <code>-MJV12nfX</code> ] <code>tag</code>
<code>descr</code> [ <code>paths</code> ... ]</p>
<p>This completion function completes all paths given to it, and also tries
to offer completions which point to the same file as one of the paths
given (relative path when an absolute path is given, and vice versa;
when <code>..</code>’s are present in the word to be completed; and some paths got
from symlinks).</p>
<p><code>-A</code>, if specified, takes the paths from the array variable specified.
Paths can also be specified on the command line as shown above. <code>-N</code>, if
specified, prevents canonicalizing the paths given before using them for
completion, in case they are already so. The options <code>-M</code>, <code>-J</code>, <code>-V</code>,
<code>-1</code>, <code>-2</code>, <code>-n</code>, <code>-F</code>, <code>-X</code> are passed to <code>compadd</code>.</p>
<p>See <code>_description</code> for a description of <code>tag</code> and <code>descr</code>.</p>
<p><span id="index-_005fcmdambivalent"></span></p>
<p><code>_cmdambivalent</code></p>
<p>Completes the remaining positional arguments as an external command. The
external command and its arguments are completed as separate arguments
(in a manner appropriate for completing <code>/usr/bin/env</code>) if there are two
or more remaining positional arguments on the command line, and as a
quoted command string (in the manner of <code>system(...)</code>) otherwise. See
also <code>_cmdstring</code> and <code>_precommand</code>.</p>
<p>This function takes no arguments.</p>
<p><span id="index-_005fcmdstring"></span></p>
<p><code>_cmdstring</code></p>
<p>Completes an external command as a single argument, as for
<code>system(...)</code>.</p>
<p><span id="index-_005fcomplete"></span></p>
<p><code>_complete</code></p>
<p>This completer generates all possible completions in a context-sensitive
manner, i.e. using the settings defined with the <code>compdef</code> function
explained above and the current settings of all special parameters. This
gives the normal completion behaviour.</p>
<p>To complete arguments of commands, <code>_complete</code> uses the utility function
<code>_normal</code>, which is in turn responsible for finding the particular
function; it is described below. Various contexts of the form
<code>-``context``-</code> are handled specifically. These are all mentioned above
as possible arguments to the <code>#compdef</code> tag.</p>
<p>Before trying to find a function for a specific context, <code>_complete</code>
checks if the parameter ‘<code>compcontext</code>’ is set. Setting ‘<code>compcontext</code>’
allows the usual completion dispatching to be overridden which is useful
in places such as a function that uses <code>vared</code> for input. If it is set
to an array, the elements are taken to be the possible matches which
will be completed using the tag ‘<code>values</code>’ and the description
‘<code>value</code>’. If it is set to an associative array, the keys are used
as the possible completions and the values (if non-empty) are used as
descriptions for the matches. If ‘<code>compcontext</code>’ is set to a string
containing colons, it should be of the form
‘<code>tag``:``descr``:``action</code>’. In this case the <code>tag</code> and <code>descr</code>
give the tag and description to use and the <code>action</code> indicates what
should be completed in one of the forms accepted by the <code>_arguments</code>
utility function described below.</p>
<p>Finally, if ‘<code>compcontext</code>’ is set to a string without colons, the value
is taken as the name of the context to use and the function defined for
that context will be called. For this purpose, there is a special
context named <code>-command-line-</code> that completes whole command lines
(commands and their arguments). This is not used by the completion
system itself but is nonetheless handled when explicitly called.</p>
<p><span id="index-_005fcorrect"></span></p>
<p><code>_correct</code></p>
<p>Generate corrections, but not completions, for the current word; this is
similar to <code>_approximate</code> but will not allow any number of extra
characters at the cursor as that completer does. The effect is similar
to spell-checking. It is based on <code>_approximate</code>, but the completer
field in the context name is <code>correct</code>.</p>
<p>For example, with:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:::::' completer \
_complete _correct _approximate
zstyle ':completion:*:correct:::' max-errors 2 not-numeric
zstyle ':completion:*:approximate:::' max-errors 3 numeric
</code></pre>
</div>
<p>correction will accept up to two errors. If a numeric argument is given,
correction will not be performed, but correcting completion will be, and
will accept as many errors as given by the numeric argument. Without a
numeric argument, first correction and then correcting completion will
be tried, with the first one accepting two errors and the second one
accepting three errors.</p>
<p>When <code>_correct</code> is called as a function, the number of errors to accept
may be given following the <code>-a</code> option. The argument is in the same form
a values to the <code>accept</code> style, all in one string.</p>
<p>This completer function is intended to be used without the
<code>_approximate</code> completer or, as in the example, just before it. Using it
after the <code>_approximate</code> completer is useless since <code>_approximate</code> will
at least generate the corrected strings generated by the <code>_correct</code>
completer — and probably more.</p>
<p><span id="index-_005fexpand"></span></p>
<p><code>_expand</code></p>
<p>This completer function does not really perform completion, but instead
checks if the word on the command line is eligible for expansion and, if
it is, gives detailed control over how this expansion is done. For this
to happen, the completion system needs to be invoked with
<code>complete-word</code>, not <code>expand-or-complete</code> (the default binding for
<code>TAB</code>), as otherwise the string will be expanded by the shell’s internal
mechanism before the completion system is started. Note also this
completer should be called before the <code>_complete</code> completer function.</p>
<p>The tags used when generating expansions are <code>all-expansions</code> for the
string containing all possible expansions, <code>expansions</code> when adding the
possible expansions as single matches and <code>original</code> when adding the
original string from the line. The order in which these strings are
generated, if at all, can be controlled by the <code>group-order</code> and
<code>tag-order</code> styles, as usual.</p>
<p>The format string for <code>all-expansions</code> and for <code>expansions</code> may contain
the sequence ‘<code>%o</code>’ which will be replaced by the original string from
the line.</p>
<p>The kind of expansion to be tried is controlled by the <code>substitute</code>,
<code>glob</code> and <code>subst-globs-only</code> styles.</p>
<p>It is also possible to call <code>_expand</code> as a function, in which case the
different modes may be selected with options: <code>-s</code> for <code>substitute</code>,
<code>-g</code> for <code>glob</code> and <code>-o</code> for <code>subst-globs-only</code>.</p>
<p><span id="index-_005fexpand_005falias"></span></p>
<p><code>_expand_alias</code></p>
<p>If the word the cursor is on is an alias, it is expanded and no other
completers are called. The types of aliases which are to be expanded can
be controlled with the styles <code>regular</code>, <code>global</code> and <code>disabled</code>.</p>
<p>This function is also a bindable command, see <a href="Completion-System.html#Bindable-Commands">Bindable
Commands</a>.</p>
<p><span id="index-_005fextensions"></span></p>
<p><code>_extensions</code></p>
<p>If the cursor follows the string ‘<code>*.</code>’, filename extensions are
completed. The extensions are taken from files in current directory or a
directory specified at the beginning of the current word. For exact
matches, completion continues to allow other completers such as
<code>_expand</code> to expand the pattern. The standard <code>add-space</code> and
<code>prefix-hidden</code> styles are observed.</p>
<p><span id="index-_005fexternal_005fpwds"></span></p>
<p><code>_external_pwds</code></p>
<p>Completes current directories of other zsh processes belonging to the
current user.</p>
<p>This is intended to be used via <code>_generic</code>, bound to a custom key
combination. Note that pattern matching is enabled so matching is
performed similar to how it works with the <code>_match</code> completer.</p>
<p><span id="index-_005fhistory"></span></p>
<p><code>_history</code></p>
<p>Complete words from the shell’s command history. This completer can be
controlled by the <code>remove-all-dups</code>, and <code>sort</code> styles as for the
<code>_history_complete_word</code> bindable command, see <a href="Completion-System.html#Bindable-Commands">Bindable
Commands</a> and <a href="Completion-System.html#Completion-System-Configuration">Completion System
Configuration</a>.</p>
<p><span id="index-_005fignored"></span></p>
<p><code>_ignored</code></p>
<p>The <code>ignored-patterns</code> style can be set to a list of patterns which are
compared against possible completions; matching ones are removed. With
this completer those matches can be reinstated, as if no
<code>ignored-patterns</code> style were set. The completer actually generates its
own list of matches; which completers are invoked is determined in the
same way as for the <code>_prefix</code> completer. The <code>single-ignored</code> style is
also available as described above.</p>
<p><span id="index-_005flist"></span></p>
<p><code>_list</code></p>
<p>This completer allows the insertion of matches to be delayed until
completion is attempted a second time without the word on the line being
changed. On the first attempt, only the list of matches will be shown.
It is affected by the styles <code>condition</code> and <code>word</code>, see <a href="Completion-System.html#Completion-System-Configuration">Completion
System Configuration</a>.</p>
<p><span id="index-_005fmatch"></span></p>
<p><code>_match</code></p>
<p>This completer is intended to be used after the <code>_complete</code> completer.
It behaves similarly but the string on the command line may be a pattern
to match against trial completions. This gives the effect of the
<code>GLOB_COMPLETE</code> option.</p>
<p>Normally completion will be performed by taking the pattern from the
line, inserting a ‘<code>*</code>’ at the cursor position and comparing the
resulting pattern with the possible completions generated. This can be
modified with the <code>match-original</code> style described above.</p>
<p>The generated matches will be offered in a menu completion unless the
<code>insert-unambiguous</code> style is set to ‘true’; see the description above
for other options for this style.</p>
<p>Note that matcher specifications defined globally or used by the
completion functions (the styles <code>matcher-list</code> and <code>matcher</code>) will not
be used.</p>
<p><span id="index-_005fmenu"></span></p>
<p><code>_menu</code></p>
<p>This completer was written as simple example function to show how menu
effect of disabling menu selection which can be useful with <code>_generic</code>
based widgets. It should be used as the first completer in the list.
Note that this is independent of the setting of the <code>MENU_COMPLETE</code>
option and does not work with the other menu completion widgets such as
<code>reverse-menu-complete</code>, or <code>accept-and-menu-complete</code>.</p>
<p><span id="index-_005foldlist"></span></p>
<p><code>_oldlist</code></p>
<p>This completer controls how the standard completion widgets behave when
there is an existing list of completions which may have been generated
by a special completion (i.e. a separately-bound completion command). It
allows the ordinary completion keys to continue to use the list of
completions thus generated, instead of producing a new list of ordinary
contextual completions. It should appear in the list of completers
before any of the widgets which generate matches. It uses two styles:
<code>old-list</code> and <code>old-menu</code>, see <a href="Completion-System.html#Completion-System-Configuration">Completion System
Configuration</a>.</p>
<p><span id="index-_005fprecommand"></span></p>
<p><code>_precommand</code></p>
<p>Complete an external command in word-separated arguments, as for <code>exec</code>
and <code>/usr/bin/env</code>.</p>
<p><span id="index-_005fprefix"></span></p>
<p><code>_prefix</code></p>
<p>This completer can be used to try completion with the suffix (everything
after the cursor) ignored. In other words, the suffix will not be
considered to be part of the word to complete. The effect is similar to
the <code>expand-or-complete-prefix</code> command.</p>
<p>The <code>completer</code> style is used to decide which other completers are to be
called to generate matches. If this style is unset, the list of
completers set for the current context is used — except, of course, the
<code>_prefix</code> completer itself. Furthermore, if this completer appears more
than once in the list of completers only those completers not already
tried by the last invocation of <code>_prefix</code> will be called.</p>
<p>For example, consider this global <code>completer</code> style:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer \
_complete _prefix _correct _prefix:foo
</code></pre>
</div>
<p>Here, the <code>_prefix</code> completer tries normal completion but ignoring the
suffix. If that doesn’t generate any matches, and neither does the call
to the <code>_correct</code> completer after it, <code>_prefix</code> will be called a second
time and, now only trying correction with the suffix ignored. On the
second invocation the completer part of the context appears as ‘<code>foo</code>’.</p>
<p>To use <code>_prefix</code> as the last resort and try only normal completion when
it is invoked:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer _complete ... _prefix
zstyle ':completion::prefix:*' completer _complete
</code></pre>
</div>
<p>The <code>add-space</code> style is also respected. If it is set to ‘true’ then
<code>_prefix</code> will insert a space between the matches generated (if any) and
the suffix.</p>
<p>Note that this completer is only useful if the <code>COMPLETE_IN_WORD</code> option
is set; otherwise, the cursor will be moved to the end of the current
word before the completion code is called and hence there will be no
suffix.</p>
<p><span id="index-_005fuser_005fexpand"></span></p>
<p><code>_user_expand</code></p>
<p>This completer behaves similarly to the <code>_expand</code> completer but instead
performs expansions defined by users. The styles <code>add-space</code> and <code>sort</code>
styles specific to the <code>_expand</code> completer are usable with
<code>_user_expand</code> in addition to other styles handled more generally by the
completion system. The tag <code>all-expansions</code> is also available.</p>
<p>The expansion depends on the array style <code>user-expand</code> being defined for
the current context; remember that the context for completers is less
specific than that for contextual completion as the full context has not
yet been determined. Elements of the array may have one of the following
forms:</p>
<ul>
<li>
<p><code>$``hash</code><br />
<code>hash</code> is the name of an associative array. Note this is not a full
parameter expression, merely a <code>$</code>, suitably quoted to prevent
immediate expansion, followed by the name of an associative array.
If the trial expansion word matches a key in <code>hash</code>, the resulting
expansion is the corresponding value.</p>
</li>
<li>
<p><code>_func</code><br />
<code>_func</code> is the name of a shell function whose name must begin with
<code>_</code> but is not otherwise special to the completion system. The
function is called with the trial word as an argument. If the word
is to be expanded, the function should set the array <code>reply</code> to a
list of expansions. Optionally, it can set <code>REPLY</code> to a word that
will be used as a description for the set of expansions. The return
status of the function is irrelevant.</p>
</li>
</ul>
<hr />
<p><span id="Bindable-Commands"></span>
<span id="Bindable-Commands-1"></span></p>
<h2 id="205-bindable-commands"><a class="header" href="#205-bindable-commands">20.5 Bindable Commands</a></h2>
<p><span id="index-completion-system_002c-bindable-commands"></span></p>
<p>In addition to the context-dependent completions provided, which are
expected to work in an intuitively obvious way, there are a few widgets
implementing special behaviour which can be bound separately to keys.
The following is a list of these and their default bindings.</p>
<p><span id="index-_005fbash_005fcompletions"></span></p>
<p><code>_bash_completions</code></p>
<p>This function is used by two widgets, <code>_bash_complete-word</code> and
<code>_bash_list-choices</code>. It exists to provide compatibility with completion
bindings in bash. The last character of the binding determines what is
completed: ‘<code>!</code>’, command names; ‘<code>$</code>’, environment variables; ‘<code>@</code>’,
host names; ‘<code>/</code>’, file names; ‘<code>~</code>’ user names. In bash, the binding
preceded by ‘<code>\e</code>’ gives completion, and preceded by ‘<code>^X</code>’ lists
options. As some of these bindings clash with standard zsh bindings,
only ‘<code>\e~</code>’ and ‘<code>^X~</code>’ are bound by default. To add the rest, the
following should be added to <code>.zshrc</code> after <code>compinit</code> has been run:</p>
<div class="example">
<pre><code class="language-example">for key in '!' '$' '@' '/' '~'; do
bindkey &quot;\e$key&quot; _bash_complete-word
bindkey &quot;^X$key&quot; _bash_list-choices
done
</code></pre>
</div>
<p>This includes the bindings for ‘<code>~</code>’ in case they were already bound to
something else; the completion code does not override user bindings.</p>
<p><span id="index-_005fcorrect_005ffilename-_0028_005eXC_0029"></span></p>
<p><code>_correct_filename</code> (<code>^XC</code>)</p>
<p>Correct the filename path at the cursor position. Allows up to six
errors in the name. Can also be called with an argument to correct a
filename path, independently of zle; the correction is printed on
standard output.</p>
<p><span id="index-_005fcorrect_005fword-_0028_005eXc_0029"></span></p>
<p><code>_correct_word</code> (<code>^Xc</code>)</p>
<p>Performs correction of the current argument using the usual contextual
completions as possible choices. This stores the string ‘<code>correct-word</code>’
in the <code>function</code> field of the context name and then calls the
<code>_correct</code> completer.</p>
<p><span id="index-_005fexpand_005falias-_0028_005eXa_0029"></span></p>
<p><code>_expand_alias</code> (<code>^Xa</code>)</p>
<p>This function can be used as a completer and as a bindable command. It
expands the word the cursor is on if it is an alias. The types of alias
expanded can be controlled with the styles <code>regular</code>, <code>global</code> and
<code>disabled</code>.</p>
<p>When used as a bindable command there is one additional feature that can
be selected by setting the <code>complete</code> style to ‘true’. In this case, if
the word is not the name of an alias, <code>_expand_alias</code> tries to complete
the word to a full alias name without expanding it. It leaves the cursor
directly after the completed word so that invoking <code>_expand_alias</code> once
more will expand the now-complete alias name.</p>
<p><span id="index-_005fexpand_005fword-_0028_005eXe_0029"></span></p>
<p><code>_expand_word</code> (<code>^Xe</code>)</p>
<p>Performs expansion on the current word: equivalent to the standard
<code>expand-word</code> command, but using the <code>_expand</code> completer. Before calling
it, the <code>function</code> field of the context is set to ‘<code>expand-word</code>’.</p>
<p><span id="index-_005fgeneric"></span></p>
<p><code>_generic</code></p>
<p>This function is not defined as a widget and not bound by default.
However, it can be used to define a widget and will then store the name
of the widget in the <code>function</code> field of the context and call the
completion system. This allows custom completion widgets with their own
set of style settings to be defined easily. For example, to define a
widget that performs normal completion and starts menu selection:</p>
<div class="example">
<pre><code class="language-example">zle -C foo complete-word _generic
bindkey '...' foo
zstyle ':completion:foo:*' menu yes select=1
</code></pre>
</div>
<p>Note in particular that the <code>completer</code> style may be set for the context
in order to change the set of functions used to generate possible
matches. If <code>_generic</code> is called with arguments, those are passed
through to <code>_main_complete</code> as the list of completers in place of those
defined by the <code>completer</code> style.</p>
<p><span id="index-_005fhistory_005fcomplete_005fword-_0028_005ce_002f_0029"></span></p>
<p><code>_history_complete_word</code> (<code>\e/</code>)</p>
<p>Complete words from the shell’s command history. This uses the <code>list</code>,
<code>remove-all-dups</code>, <code>sort</code>, and <code>stop</code> styles.</p>
<p><span id="index-_005fmost_005frecent_005ffile-_0028_005eXm_0029"></span></p>
<p><code>_most_recent_file</code> (<code>^Xm</code>)</p>
<p>Complete the name of the most recently modified file matching the
pattern on the command line (which may be blank). If given a numeric
argument <code>N</code>, complete the <code>N</code>th most recently modified file. Note the
completion, if any, is always unique.</p>
<p><span id="index-_005fnext_005ftags-_0028_005eXn_0029"></span></p>
<p><code>_next_tags</code> (<code>^Xn</code>)</p>
<p>This command alters the set of matches used to that for the next tag, or
set of tags, either as given by the <code>tag-order</code> style or as set by
default; these matches would otherwise not be available. Successive
invocations of the command cycle through all possible sets of tags.</p>
<p><span id="index-_005fread_005fcomp-_0028_005eX_005eR_0029"></span></p>
<p><code>_read_comp</code> (<code>^X^R</code>)</p>
<p>Prompt the user for a string, and use that to perform completion on the
current word. There are two possibilities for the string. First, it can
be a set of words beginning ‘<code>_</code>’, for example ‘<code>_files -/</code>’, in which
case the function with any arguments will be called to generate the
completions. Unambiguous parts of the function name will be completed
automatically (normal completion is not available at this point) until a
space is typed.</p>
<p>Second, any other string will be passed as a set of arguments to
<code>compadd</code> and should hence be an expression specifying what should be
completed.</p>
<p>A very restricted set of editing commands is available when reading the
string: ‘<code>DEL</code>’ and ‘<code>^H</code>’ delete the last character; ‘<code>^U</code>’ deletes the
line, and ‘<code>^C</code>’ and ‘<code>^G</code>’ abort the function, while ‘<code>RET</code>’ accepts
the completion. Note the string is used verbatim as a command line, so
arguments must be quoted in accordance with standard shell rules.</p>
<p>Once a string has been read, the next call to <code>_read_comp</code> will use the
existing string instead of reading a new one. To force a new string to
be read, call <code>_read_comp</code> with a numeric argument.</p>
<p><span id="index-_005fcomplete_005fdebug-_0028_005eX_003f_0029"></span></p>
<p><code>_complete_debug</code> (<code>^X?</code>)</p>
<p>This widget performs ordinary completion, but captures in a temporary
file a trace of the shell commands executed by the completion system.
Each completion attempt gets its own file. A command to view each of
these files is pushed onto the editor buffer stack.</p>
<p><span id="index-_005fcomplete_005fhelp-_0028_005eXh_0029"></span></p>
<p><code>_complete_help</code> (<code>^Xh</code>)</p>
<p>This widget displays information about the context names, the tags, and
the completion functions used when completing at the current cursor
position. If given a numeric argument other than <code>1</code> (as in ‘<code>ESC-2 ^Xh</code>’), then the styles used and the contexts for which they are used
will be shown, too.</p>
<p>Note that the information about styles may be incomplete; it depends on
the information available from the completion functions called, which in
turn is determined by the user’s own styles and other settings.</p>
<p><span id="index-_005fcomplete_005fhelp_005fgeneric"></span></p>
<p><code>_complete_help_generic</code></p>
<p>Unlike other commands listed here, this must be created as a normal ZLE
widget rather than a completion widget (i.e. with <code>zle -N</code>). It is used
for generating help with a widget bound to the <code>_generic</code> widget that is
described above.</p>
<p>If this widget is created using the name of the function, as it is by
default, then when executed it will read a key sequence. This is
expected to be bound to a call to a completion function that uses the
<code>_generic</code> widget. That widget will be executed, and information
provided in the same format that the <code>_complete_help</code> widget displays
for contextual completion.</p>
<p>If the widget’s name contains <code>debug</code>, for example if it is created as
‘<code>zle -N _complete_debug_generic _complete_help_generic</code>’, it will
read and execute the keystring for a generic widget as before, but then
generate debugging information as done by <code>_complete_debug</code> for
contextual completion.</p>
<p>If the widget’s name contains <code>noread</code>, it will not read a keystring but
instead arrange that the next use of a generic widget run in the same
shell will have the effect as described above.</p>
<p>The widget works by setting the shell parameter
<code>ZSH_TRACE_GENERIC_WIDGET</code> which is read by <code>_generic</code>. Unsetting the
parameter cancels any pending effect of the <code>noread</code> form.</p>
<p>For example, after executing the following:</p>
<div class="example">
<pre><code class="language-example">zle -N _complete_debug_generic _complete_help_generic
bindkey '^x:' _complete_debug_generic
</code></pre>
</div>
<p>typing ‘<code>C-x :</code>’ followed by the key sequence for a generic widget will
cause trace output for that widget to be saved to a file.</p>
<p><span id="index-_005fcomplete_005ftag-_0028_005eXt_0029"></span></p>
<p><code>_complete_tag</code> (<code>^Xt</code>)</p>
<p>This widget completes symbol tags created by the <code>etags</code> or <code>ctags</code>
programmes (note there is no connection with the completion system’s
tags) stored in a file <code>TAGS</code>, in the format used by <code>etags</code>, or <code>tags</code>,
in the format created by <code>ctags</code>. It will look back up the path
hierarchy for the first occurrence of either file; if both exist, the
file <code>TAGS</code> is preferred. You can specify the full path to a <code>TAGS</code> or
<code>tags</code> file by setting the parameter <code>$TAGSFILE</code> or <code>$tagsfile</code>
respectively. The corresponding completion tags used are <code>etags</code> and
<code>vtags</code>, after emacs and vi respectively.</p>
<hr />
<p><span id="Completion-Functions"></span>
<span id="Utility-Functions-1"></span></p>
<h2 id="206-utility-functions"><a class="header" href="#206-utility-functions">20.6 Utility Functions</a></h2>
<p><span id="index-completion-system_002c-utility-functions"></span></p>
<p>Descriptions follow for utility functions that may be useful when
writing completion functions. If functions are installed in
subdirectories, most of these reside in the <code>Base</code> subdirectory. Like
the example functions for commands in the distribution, the utility
functions generating matches all follow the convention of returning
status zero if they generated completions and non-zero if no matching
completions could be added.</p>
<p><span id="index-_005fabsolute_005fcommand_005fpaths"></span></p>
<p><code>_absolute_command_paths</code></p>
<p>This function completes external commands as absolute paths (unlike
<code>_command_names -e</code> which completes their basenames). It takes no
arguments.</p>
<p><span id="index-_005fall_005flabels"></span></p>
<p><code>_all_labels</code> [ <code>-x</code> ] [ <code>-12VJ</code> ] <code>tag</code> <code>name</code> <code>descr</code> [ <code>command</code>
<code>arg</code> ... ]</p>
<p>This is a convenient interface to the <code>_next_label</code> function below,
implementing the loop shown in the <code>_next_label</code> example. The <code>command</code>
and its arguments are called to generate the matches. The options stored
in the parameter <code>name</code> will automatically be inserted into the <code>arg</code>s
passed to the <code>command</code>. Normally, they are put directly after the
<code>command</code>, but if one of the <code>arg</code>s is a single hyphen, they are
inserted directly before that. If the hyphen is the last argument, it
will be removed from the argument list before the <code>command</code> is called.
This allows <code>_all_labels</code> to be used in almost all cases where the
matches can be generated by a single call to the <code>compadd</code> builtin
command or by a call to one of the utility functions.</p>
<p>For example:</p>
<div class="example">
<pre><code class="language-example">local expl
...
if _requested foo; then
...
_all_labels foo expl '...' compadd ... - $matches
fi
</code></pre>
</div>
<p>Will complete the strings from the <code>matches</code> parameter, using <code>compadd</code>
with additional options which will take precedence over those generated
by <code>_all_labels</code>.</p>
<p><span id="index-_005falternative"></span></p>
<p><code>_alternative</code> [ <code>-O</code> <code>name</code> ] [ <code>-C</code> <code>name</code> ] <code>spec</code> ...</p>
<p>This function is useful in simple cases where multiple tags are
available. Essentially it implements a loop like the one described for
the <code>_tags</code> function below.</p>
<p>The tags to use and the action to perform if a tag is requested are
described using the <code>spec</code>s which are of the form:
‘<code>tag``:``descr``:``action</code>’. The <code>tag</code>s are offered using <code>_tags</code> and
if the tag is requested, the <code>action</code> is executed with the given
description <code>descr</code>. The <code>action</code>s are those accepted by the
<code>_arguments</code> function (described below), excluding the ‘<code>-&gt;``state</code>’ and
‘<code>=``...</code>’ forms.</p>
<p>For example, the <code>action</code> may be a simple function call:</p>
<div class="example">
<pre><code class="language-example">_alternative \
'users:user:_users' \
'hosts:host:_hosts'
</code></pre>
</div>
<p>offers usernames and hostnames as possible matches, generated by the
<code>_users</code> and <code>_hosts</code> functions respectively.</p>
<p>Like <code>_arguments</code>, this function uses <code>_all_labels</code> to execute the
actions, which will loop over all sets of tags. Special handling is only
required if there is an additional valid tag, for example inside a
function called from <code>_alternative</code>.</p>
<p>The option ‘<code>-O</code> <code>name</code>’ is used in the same way as by the <code>_arguments</code>
function. In other words, the elements of the <code>name</code> array will be
passed to <code>compadd</code> when executing an action.</p>
<p>Like <code>_tags</code> this function supports the <code>-C</code> option to give a different
name for the argument context field.</p>
<p><span id="index-_005farguments"></span></p>
<p><code>_arguments </code>[ <code>-nswWCRS</code> ] [ <code>-A</code> <code>pat</code> ] [ <code>-O</code> <code>name</code> ] [
<code>-M</code> <code>matchspec</code> ]</p>
<p><code>           </code>[ <code>:</code> ] <code>spec</code> ...</p>
<p><code>_arguments </code>[ <code>opt</code> ... ] <code>-``-</code> [ <code>-l</code> ] [ <code>-i</code> <code>pats</code> ] [
<code>-s</code> <code>pair</code> ]</p>
<p><code>           </code>[ <code>helpspec</code> ...]</p>
<p>This function can be used to give a complete specification for
completion for a command whose arguments follow standard UNIX option and
argument conventions.</p>
<p><em>Options Overview</em></p>
<p>Options to <code>_arguments</code> itself must be in separate words, i.e. <code>-s -w</code>,
not <code>-sw</code>. The options are followed by <code>spec</code>s that describe options and
arguments of the analyzed command. To avoid ambiguity, all options to
<code>_arguments</code> itself may be separated from the <code>spec</code> forms by a single
colon.</p>
<p>The ‘<code>-``-</code>’ form is used to intuit <code>spec</code> forms from the help output of
the command being analyzed, and is described in detail below. The <code>opts</code>
for the ‘<code>-``-</code>’ form are otherwise the same options as the first form.
Note that ‘<code>-s</code>’ following ‘<code>-``-</code>’ has a distinct meaning from ‘<code>-s</code>’
preceding ‘<code>-``-</code>’, and both may appear.</p>
<p>The option switches <code>-s</code>, <code>-S</code>, <code>-A</code>, <code>-w</code>, and <code>-W</code> affect how
<code>_arguments</code> parses the analyzed command line’s options. These switches
are useful for commands with standard argument parsing.</p>
<p>The options of <code>_arguments</code> have the following meanings:</p>
<ul>
<li>
<p><code>-n</code><br />
With this option, <code>_arguments</code> sets the parameter <code>NORMARG</code> to the
position of the first normal argument in the <code>$words</code> array, i.e.
the position after the end of the options. If that argument has not
been reached, <code>NORMARG</code> is set to <code>-1</code>. The caller should declare
‘<code>integer NORMARG</code>’ if the <code>-n</code> option is passed; otherwise the
parameter is not used.</p>
</li>
<li>
<p><code>-s</code><br />
Enable <em>option stacking</em> for single-letter options, whereby multiple
single-letter options may be combined into a single word. For
example, the two options ‘<code>-x</code>’ and ‘<code>-y</code>’ may be combined into a
single word ‘<code>-xy</code>’. By default, every word corresponds to a single
option name (‘<code>-xy</code>’ is a single option named ‘<code>xy</code>’).</p>
<p>Options beginning with a single hyphen or plus sign are eligible for
stacking; words beginning with two hyphens are not.</p>
<p>Note that <code>-s</code> after <code>-``-</code> has a different meaning, which is
documented in the segment entitled ‘Deriving <code>spec</code> forms from the
help output’.</p>
</li>
<li>
<p><code>-w</code><br />
In combination with <code>-s</code>, allow option stacking even if one or more
of the options take arguments. For example, if <code>-x</code> takes an
argument, with no <code>-s</code>, ‘<code>-xy</code>’ is considered as a single
(unhandled) option; with <code>-s</code>, <code>-xy</code> is an option with the argument
‘<code>y</code>’; with both <code>-s</code> and <code>-w</code>, <code>-xy</code> is the option <code>-x</code> and the
option <code>-y</code> with arguments to <code>-x</code> (and to <code>-y</code>, if it takes
arguments) still to come in subsequent words.</p>
</li>
<li>
<p><code>-W</code><br />
This option takes <code>-w</code> a stage further: it is possible to complete
single-letter options even after an argument that occurs in the same
word. However, it depends on the action performed whether options
will really be completed at this point. For more control, use a
utility function like <code>_guard</code> as part of the action.</p>
</li>
<li>
<p><code>-C</code><br />
Modify the <code>curcontext</code> parameter for an action of the form
‘<code>-&gt;``state</code>’. This is discussed in detail below.</p>
</li>
<li>
<p><code>-R</code><br />
Return status 300 instead of zero when a <code>$state</code> is to be handled,
in the ‘<code>-&gt;``string</code>’ syntax.</p>
</li>
<li>
<p><code>-S</code><br />
Do not complete options after a ‘<code>-``-</code>’ appearing on the line, and
ignore the ‘<code>-``-</code>’. For example, with <code>-S</code>, in the line</p>
<div class="example">
<pre><code class="language-example">foobar -x -- -y
</code></pre>
</div>
<p>the ‘<code>-x</code>’ is considered an option, the ‘<code>-y</code>’ is considered an
argument, and the ‘<code>-``-</code>’ is considered to be neither.</p>
</li>
<li>
<p><code>-A</code> <code>pat</code><br />
Do not complete options after the first non-option argument on the
line. <code>pat</code> is a pattern matching all strings which are not to be
taken as arguments. For example, to make <code>_arguments</code> stop
completing options after the first normal argument, but ignoring all
strings starting with a hyphen even if they are not described by one
of the <code>optspec</code>s, the form is ‘<code>-A &quot;-*&quot;</code>’.</p>
</li>
<li>
<p><code>-O</code> <code>name</code><br />
Pass the elements of the array <code>name</code> as arguments to functions
called to execute <code>action</code>s. This is discussed in detail below.</p>
</li>
<li>
<p><code>-M</code> <code>matchspec</code><br />
Use the match specification <code>matchspec</code> for completing option names
and values. The default <code>matchspec</code> allows partial word completion
after ‘<code>_</code>’ and ‘<code>-</code>’, such as completing ‘<code>-f-b</code>’ to ‘<code>-foo-bar</code>’.
The default <code>matchspec</code> is:</p>
<div class="example">
<pre><code class="language-example">r:|[_-]=* r:|=*
</code></pre>
</div>
</li>
</ul>
<p><em><code>spec</code>s: overview</em></p>
<p>Each of the following forms is a <code>spec</code> describing individual sets of
options or arguments on the command line being analyzed.</p>
<ul>
<li>
<p><code>n``:``message``:``action</code><br />
<code>n``::``message``:``action</code><br />
This describes the <code>n</code>’th normal argument. The <code>message</code> will be
printed above the matches generated and the <code>action</code> indicates what
can be completed in this position (see below). If there are two
colons before the <code>message</code> the argument is optional. If the
<code>message</code> contains only white space, nothing will be printed above
the matches unless the action adds an explanation string itself.</p>
</li>
<li>
<p><code>:``message``:``action</code><br />
<code>::``message``:``action</code><br />
Similar, but describes the <em>next</em> argument, whatever number that
happens to be. If all arguments are specified in this form in the
correct order the numbers are unnecessary.</p>
</li>
<li>
<p><code>*:``message``:``action</code><br />
<code>*::``message``:``action</code><br />
<code>*:::``message``:``action</code><br />
This describes how arguments (usually non-option arguments, those
not beginning with <code>-</code> or <code>+</code>) are to be completed when neither of
the first two forms was provided. Any number of arguments can be
completed in this fashion.</p>
<p>With two colons before the <code>message</code>, the <code>words</code> special array and
the <code>CURRENT</code> special parameter are modified to refer only to the
normal arguments when the <code>action</code> is executed or evaluated. With
three colons before the <code>message</code> they are modified to refer only to
the normal arguments covered by this description.</p>
</li>
<li>
<p><code>optspec</code><br />
<code>optspec``:``...</code><br />
This describes an option. The colon indicates handling for one or
more arguments to the option; if it is not present, the option is
assumed to take no arguments.</p>
<p>The following forms are available for the initial <code>optspec</code>, whether
or not the option has arguments.</p>
<ul>
<li>
<p><code>*``optspec</code><br />
Here <code>optspec</code> is one of the remaining forms below. This
indicates the following <code>optspec</code> may be repeated. Otherwise if
the corresponding option is already present on the command line
to the left of the cursor it will not be offered again.</p>
</li>
<li>
<p><code>-``optname</code><br />
<code>+``optname</code><br />
In the simplest form the <code>optspec</code> is just the option name
beginning with a minus or a plus sign, such as ‘<code>-foo</code>’. The
first argument for the option (if any) must follow as a
<em>separate</em> word directly after the option.</p>
<p>Either of ‘<code>-+``optname</code>’ and ‘<code>+-``optname</code>’ can be used to
specify that <code>-``optname</code> and <code>+``optname</code> are both valid.</p>
<p>In all the remaining forms, the leading ‘<code>-</code>’ may be replaced by
or paired with ‘<code>+</code>’ in this way.</p>
</li>
<li>
<p><code>-``optname``-</code><br />
The first argument of the option must come directly after the
option name <em>in the same word</em>. For example, ‘<code>-foo-:``...</code>’
specifies that the completed option and argument will look like
‘<code>-foo``arg</code>’.</p>
</li>
<li>
<p><code>-``optname``+</code><br />
The first argument may appear immediately after <code>optname</code> in the
same word, or may appear as a separate word after the option.
For example, ‘<code>-foo+:``...</code>’ specifies that the completed option
and argument will look like either ‘<code>-foo``arg</code>’ or ‘<code>-foo</code>
<code>arg</code>’.</p>
</li>
<li>
<p><code>-``optname``=</code><br />
The argument may appear as the next word, or in same word as the
option name provided that it is separated from it by an equals
sign, for example ‘<code>-foo=``arg</code>’ or ‘<code>-foo</code> <code>arg</code>’.</p>
</li>
<li>
<p><code>-``optname``=-</code><br />
The argument to the option must appear after an equals sign in
the same word, and may not be given in the next argument.</p>
</li>
<li>
<p><code>optspec``[``explanation``]</code><br />
An explanation string may be appended to any of the preceding
forms of <code>optspec</code> by enclosing it in brackets, as in ‘<code>-q[query operation]</code>’.</p>
<p>The <code>verbose</code> style is used to decide whether the explanation
strings are displayed with the option in a completion listing.</p>
<p>If no bracketed explanation string is given but the
<code>auto-description</code> style is set and only one argument is
described for this <code>optspec</code>, the value of the style is
displayed, with any appearance of the sequence ‘<code>%d</code>’ in it
replaced by the <code>message</code> of the first <code>optarg</code> that follows the
<code>optspec</code>; see below.</p>
</li>
</ul>
<p>It is possible for options with a literal ‘<code>+</code>’ or ‘<code>=</code>’ to appear,
but that character must be quoted, for example ‘<code>-\+</code>’.</p>
<p>Each <code>optarg</code> following an <code>optspec</code> must take one of the following
forms:</p>
<ul>
<li>
<p><code>:``message``:``action</code><br />
<code>::``message``:``action</code><br />
An argument to the option; <code>message</code> and <code>action</code> are treated as
for ordinary arguments. In the first form, the argument is
mandatory, and in the second form it is optional.</p>
<p>This group may be repeated for options which take multiple
arguments. In other words,
<code>:``message1``:``action1``:``message2``:``action2</code> specifies
that the option takes two arguments.</p>
</li>
<li>
<p><code>:*``pattern``:``message``:``action</code><br />
<code>:*``pattern``::``message``:``action</code><br />
<code>:*``pattern``:::``message``:``action</code><br />
This describes multiple arguments. Only the last <code>optarg</code> for an
option taking multiple arguments may be given in this form. If
the <code>pattern</code> is empty (i.e. <code>:*:</code>), all the remaining words on
the line are to be completed as described by the <code>action</code>;
otherwise, all the words up to and including a word matching the
<code>pattern</code> are to be completed using the <code>action</code>.</p>
<p>Multiple colons are treated as for the ‘<code>*:``...</code>’ forms for
ordinary arguments: when the <code>message</code> is preceded by two
colons, the <code>words</code> special array and the <code>CURRENT</code> special
parameter are modified during the execution or evaluation of the
<code>action</code> to refer only to the words after the option. When
preceded by three colons, they are modified to refer only to the
words covered by this description.</p>
</li>
</ul>
</li>
</ul>
<p>Any literal colon in an <code>optname</code>, <code>message</code>, or <code>action</code> must be
preceded by a backslash, ‘<code>\:</code>’.</p>
<p>Each of the forms above may be preceded by a list in parentheses of
option names and argument numbers. If the given option is on the command
line, the options and arguments indicated in parentheses will not be
offered. For example, ‘<code>(-two -three 1)-one:``...</code>’ completes the option
‘<code>-one</code>’; if this appears on the command line, the options <code>-two</code> and
<code>-three</code> and the first ordinary argument will not be completed after it.
‘<code>(-foo):``...</code>’ specifies an ordinary argument completion; <code>-foo</code> will
not be completed if that argument is already present.</p>
<p>Other items may appear in the list of excluded options to indicate
various other items that should not be applied when the current
specification is matched: a single star (<code>*</code>) for the rest arguments
(i.e. a specification of the form ‘<code>*:``...</code>’); a colon (<code>:</code>) for all
normal (non-option-) arguments; and a hyphen (<code>-</code>) for all options. For
example, if ‘<code>(*)</code>’ appears before an option and the option appears on
the command line, the list of remaining arguments completed.</p>
<p>To aid in reuse of specifications, it is possible to precede any of the
forms above with ‘<code>!</code>’; then the form will no longer be completed,
although if the option or argument appears on the command line they will
be skipped as normal. The main use for this is when the arguments are
given by an array, and <code>_arguments</code> is called repeatedly for more
specific contexts: on the first call ‘<code>_arguments $global_options</code>’ is
used, and on subsequent calls ‘<code>_arguments !$^global_options</code>’.</p>
<p><em><code>spec</code>s: actions</em></p>
<p>In each of the forms above the <code>action</code> determines how completions
should be generated. Except for the ‘<code>-&gt;``string</code>’ form below, the
<code>action</code> will be executed by calling the <code>_all_labels</code> function to
process all tag labels. No special handling of tags is needed unless a
function call introduces a new one.</p>
<p>The functions called to execute <code>action</code>s will be called with the
elements of the array named by the ‘<code>-O</code> <code>name</code>’ option as arguments.
This can be used, for example, to pass the same set of options for the
<code>compadd</code> builtin to all <code>action</code>s.</p>
<p>The forms for <code>action</code> are as follows.</p>
<ul>
<li>
<p><code> </code>(single unquoted space)<br />
This is useful where an argument is required but it is not possible
or desirable to generate matches for it. The <code>message</code> will be
displayed but no completions listed. Note that even in this case the
colon at the end of the <code>message</code> is needed; it may only be omitted
when neither a <code>message</code> nor an <code>action</code> is given.</p>
</li>
<li>
<p><code>(``item1</code> <code>item2</code> <code>...``)</code><br />
One of a list of possible matches, for example:</p>
<div class="example">
<pre><code class="language-example">:foo:(foo bar baz)
</code></pre>
</div>
</li>
<li>
<p><code>((item1\:desc1 ...))</code><br />
Similar to the above, but with descriptions for each possible match.
Note the backslash before the colon. For example,</p>
<div class="example">
<pre><code class="language-example">:foo:((a\:bar b\:baz))
</code></pre>
</div>
<p>The matches will be listed together with their descriptions if the
<code>description</code> style is set with the <code>values</code> tag in the context.</p>
</li>
<li>
<p><code>-&gt;``string</code><br />
<span id="index-context_002c-use-of"></span>
<span id="index-line_002c-use-of"></span>
<span id="index-opt_005fargs_002c-use-of"></span></p>
<p>In this form, <code>_arguments</code> processes the arguments and options and
then returns control to the calling function with parameters set to
indicate the state of processing; the calling function then makes
its own arrangements for generating completions. For example,
functions that implement a state machine can use this type of
action.</p>
<p>Where <code>_arguments</code> encounters <code>action</code> in the ‘<code>-&gt;``string</code>’ format,
it will strip all leading and trailing whitespace from <code>string</code> and
set the array <code>state</code> to the set of all <code>string</code>s for which an
action is to be performed. The elements of the array <code>state_descr</code>
are assigned the corresponding <code>message</code> field from each <code>optarg</code>
containing such an <code>action</code>.</p>
<p>By default and in common with all other well behaved completion
functions, _arguments returns status zero if it was able to add
matches and non-zero otherwise. However, if the <code>-R</code> option is
given, <code>_arguments</code> will instead return a status of 300 to indicate
that <code>$state</code> is to be handled.</p>
<p>In addition to <code>$state</code> and <code>$state_descr</code>, <code>_arguments</code> also sets
the global parameters ‘<code>context</code>’, ‘<code>line</code>’ and ‘<code>opt_args</code>’ as
described below, and does not reset any changes made to the special
parameters such as <code>PREFIX</code> and <code>words</code>. This gives the calling
function the choice of resetting these parameters or propagating
changes in them.</p>
<p>A function calling <code>_arguments</code> with at least one action containing
a ‘<code>-&gt;``string</code>’ must therefore declare appropriate local
parameters:</p>
<div class="example">
<pre><code class="language-example">local context state state_descr line
typeset -A opt_args
</code></pre>
</div>
<p>to prevent <code>_arguments</code> from altering the global environment.</p>
</li>
<li>
<p><code>{``eval-string``}</code><br />
<span id="index-expl_002c-use-of"></span></p>
<p>A string in braces is evaluated as shell code to generate matches.
If the <code>eval-string</code> itself does not begin with an opening
parenthesis or brace it is split into separate words before
execution.</p>
</li>
<li>
<p><code> = ``action</code><br />
If the <code>action</code> starts with ‘<code>= </code>’ (an equals sign followed by a
space), <code>_arguments</code> will insert the contents of the <code>argument</code>
field of the current context as the new first element in the <code>words</code>
special array and increment the value of the <code>CURRENT</code> special
parameter. This has the effect of inserting a dummy word onto the
completion command line while not changing the point at which
completion is taking place.</p>
<p>This is most useful with one of the specifiers that restrict the
words on the command line on which the <code>action</code> is to operate (the
two- and three-colon forms above). One particular use is when an
<code>action</code> itself causes <code>_arguments</code> on a restricted range; it is
necessary to use this trick to insert an appropriate command name
into the range for the second call to <code>_arguments</code> to be able to
parse the line.</p>
</li>
<li>
<p><code> word...</code><br />
<code>word...</code><br />
This covers all forms other than those above. If the <code>action</code> starts
with a space, the remaining list of words will be invoked unchanged.</p>
<p>Otherwise it will be invoked with some extra strings placed after
the first word; these are to be passed down as options to the
<code>compadd</code> builtin. They ensure that the state specified by
<code>_arguments</code>, in particular the descriptions of options and
arguments, is correctly passed to the completion command. These
additional arguments are taken from the array parameter ‘<code>expl</code>’;
this will be set up before executing the <code>action</code> and hence may be
referred to inside it, typically in an expansion of the form
‘<code>$expl[@]</code>’ which preserves empty elements of the array.</p>
</li>
</ul>
<p>During the performance of the action the array ‘<code>line</code>’ will be set to
the normal arguments from the command line, i.e. the words from the
command line after the command name excluding all options and their
arguments. Options are stored in the associative array ‘<code>opt_args</code>’ with
option names as keys and their arguments as the values. For options that
have more than one argument these are given as one string, separated by
colons. All colons and backslashes in the original arguments are
preceded with backslashes.</p>
<p>The parameter ‘<code>context</code>’ is set when returning to the calling function
to perform an action of the form ‘<code>-&gt;``string</code>’. It is set to an array
of elements corresponding to the elements of <code>$state</code>. Each string of
the form ‘<code>option``-opt``-``n</code>’ for the <code>n</code>’th argument of the option
<code>-opt</code>, or a string of the form ‘<code>argument-``n</code>’ for the <code>n</code>’th
argument. For ‘rest’ arguments, that is those in the list at the end not
handled by position, <code>n</code> is the string ‘<code>rest</code>’. For example, when
completing the argument of the <code>-o</code> option, the name is ‘<code>option-o-1</code>’,
while for the second normal (non-option-) argument it is ‘<code>argument-2</code>’.</p>
<p>Furthermore, during the evaluation of the <code>action</code> the context name in
the <code>curcontext</code> parameter is altered to append the same string that is
stored in the <code>context</code> parameter.</p>
<p>The option <code>-C</code> tells <code>_arguments</code> to modify the <code>curcontext</code> parameter
for an action of the form ‘<code>-&gt;``state</code>’. This is the standard parameter
used to keep track of the current context. Here it (and not the
<code>context</code> array) should be made local to the calling function to avoid
passing back the modified value and should be initialised to the current
value at the start of the function:</p>
<div class="example">
<pre><code class="language-example">local curcontext=&quot;$curcontext&quot;
</code></pre>
</div>
<p>This is useful where it is not possible for multiple states to be valid
together.</p>
<p><em>Grouping Options</em></p>
<p>Options can be grouped to simplify exclusion lists. A group is
introduced with ‘<code>+</code>’ followed by a name for the group in the subsequent
word. Whole groups can then be referenced in an exclusion list or a
group name can be used to disambiguate between two forms of the same
option. For example:</p>
<div class="example">
<pre><code class="language-example">_arguments \
'(group2--x)-a' \
+ group1 \
-m \
'(group2)-n' \
+ group2 \
-x -y
</code></pre>
</div>
<p>If the name of a group is specified in the form ‘<code>(``name``)</code>’ then only
one value from that group will ever be completed; more formally, all
specifications are mutually exclusive to all other specifications in
that group. This is useful for defining options that are aliases for
each other. For example:</p>
<div class="example">
<pre><code class="language-example">_arguments \
-a -b \
+ '(operation)' \
{-c,--compress}'[compress]' \
{-d,--decompress}'[decompress]' \
{-l,--list}'[list]'
</code></pre>
</div>
<p>If an option in a group appears on the command line, it is stored in the
associative array ‘<code>opt_args</code>’ with ’<code>group``-``option</code>’ as a key. In
the example above, a key ‘<code>operation–c</code>’ is used if the option ‘<code>-c</code>’ is
present on the command line.</p>
<p><em>Specifying Multiple Sets of Arguments</em></p>
<p>It is possible to specify multiple sets of options and arguments with
the sets separated by single hyphens. This differs from groups in that
sets are considered to be mutually exclusive of each other.</p>
<p>Specifications before the first set and from any group are common to all
sets. For example:</p>
<div class="example">
<pre><code class="language-example">_arguments \
-a \
- set1 \
-c \
- set2 \
-d \
':arg:(x2 y2)'
</code></pre>
</div>
<p>This defines two sets. When the command line contains the option ‘<code>-c</code>’,
the ‘<code>-d</code>’ option and the argument will not be considered possible
completions. When it contains ‘<code>-d</code>’ or an argument, the option ‘<code>-c</code>’
will not be considered. However, after ‘<code>-a</code>’ both sets will still be
considered valid.</p>
<p>As for groups, the name of a set may appear in exclusion lists, either
alone or preceding a normal option or argument specification.</p>
<p>The completion code has to parse the command line separately for each
set. This can be slow so sets should only be used when necessary. A
useful alternative is often an option specification with rest-arguments
(as in ‘<code>-foo:*:...</code>’); here the option <code>-foo</code> swallows up all remaining
arguments as described by the <code>optarg</code> definitions.</p>
<p><em>Deriving <code>spec</code> forms from the help output</em></p>
<p>The option ‘<code>-``-</code>’ allows <code>_arguments</code> to work out the names of long
options that support the ‘<code>-``-help</code>’ option which is standard in many
GNU commands. The command word is called with the argument ‘<code>-``-help</code>’
and the output examined for option names. Clearly, it can be dangerous
to pass this to commands which may not support this option as the
behaviour of the command is unspecified.</p>
<p>In addition to options, ‘<code>_arguments -``-</code>’ will try to deduce the types
of arguments available for options when the form ‘<code>-``-``opt``=``val</code>’
is valid. It is also possible to provide hints by examining the help
text of the command and adding <code>helpspec</code> of the form
‘<code>pattern``:``message``:``action</code>’; note that other <code>_arguments</code>
<code>spec</code> forms are not used. The <code>pattern</code> is matched against the help
text for an option, and if it matches the <code>message</code> and <code>action</code> are
used as for other argument specifiers. The special case of ‘<code>*:</code>’ means
both <code>message</code> and <code>action</code> are empty, which has the effect of causing
options having no description in the help output to be ordered in
listings ahead of options that have a description.</p>
<p>For example:</p>
<div class="example">
<pre><code class="language-example">_arguments -- '*\*:toggle:(yes no)' \
'*=FILE*:file:_files' \
'*=DIR*:directory:_files -/' \
'*=PATH*:directory:_files -/'
</code></pre>
</div>
<p>Here, ‘<code>yes</code>’ and ‘<code>no</code>’ will be completed as the argument of options
whose description ends in a star; file names will be completed for
options that contain the substring ‘<code>=FILE</code>’ in the description; and
directories will be completed for options whose description contains
‘<code>=DIR</code>’ or ‘<code>=PATH</code>’. The last three are in fact the default and so
need not be given explicitly, although it is possible to override the
use of these patterns. A typical help text which uses this feature is:</p>
<div class="example">
<pre><code class="language-example"> -C, --directory=DIR change to directory DIR
</code></pre>
</div>
<p>so that the above specifications will cause directories to be completed
after ‘<code>-``-directory</code>’, though not after ‘<code>-C</code>’.</p>
<p>Note also that <code>_arguments</code> tries to find out automatically if the
argument for an option is optional. This can be specified explicitly by
doubling the colon before the <code>message</code>.</p>
<p>If the <code>pattern</code> ends in ‘<code>(-)</code>’, this will be removed from the pattern
and the <code>action</code> will be used only directly after the ‘<code>=</code>’, not in the
next word. This is the behaviour of a normal specification defined with
the form ‘<code>=-</code>’.</p>
<p>By default, the command (with the option ‘<code>–help</code>’) is run after
resetting all the locale categories (except for <code>LC_CTYPE</code>) to ‘<code>C</code>’. If
the localized help output is known to work, the option ‘<code>-l</code>’ can be
specified after the ‘<code>_arguments -``-</code>’ so that the command is run in
the current locale.</p>
<p>The ‘<code>_arguments -``-</code>’ can be followed by the option ‘<code>-i</code> <code>patterns</code>’
to give patterns for options which are not to be completed. The patterns
can be given as the name of an array parameter or as a literal list in
parentheses. For example,</p>
<div class="example">
<pre><code class="language-example">_arguments -- -i \
&quot;(--(en|dis)able-FEATURE*)&quot;
</code></pre>
</div>
<p>will cause completion to ignore the options ‘<code>-``-enable-FEATURE</code>’ and
‘<code>-``-disable-FEATURE</code>’ (this example is useful with GNU <code>configure</code>).</p>
<p>The ‘<code>_arguments -``-</code>’ form can also be followed by the option ‘<code>-s</code>
<code>pair</code>’ to describe option aliases. The <code>pair</code> consists of a list of
alternating patterns and corresponding replacements, enclosed in parens
and quoted so that it forms a single argument word in the <code>_arguments</code>
call.</p>
<p>For example, some <code>configure</code>-script help output describes options only
as ‘<code>-``-enable-foo</code>’, but the script also accepts the negated form
‘<code>-``-disable-foo</code>’. To allow completion of the second form:</p>
<div class="example">
<pre><code class="language-example">_arguments -- -s &quot;((#s)--enable- --disable-)&quot;
</code></pre>
</div>
<p><em>Miscellaneous notes</em></p>
<p>Finally, note that <code>_arguments</code> generally expects to be the primary
function handling any completion for which it is used. It may have side
effects which change the treatment of any matches added by other
functions called after it. To combine <code>_arguments</code> with other functions,
those functions should be called either before <code>_arguments</code>, as an
<code>action</code> within a <code>spec</code>, or in handlers for ‘<code>-&gt;``state</code>’ actions.</p>
<p>Here is a more general example of the use of <code>_arguments</code>:</p>
<div class="example">
<pre><code class="language-example">_arguments '-l+:left border:' \
'-format:paper size:(letter A4)' \
'*-copy:output file:_files::resolution:(300 600)' \
':postscript file:_files -g \*.\(ps\|eps\)' \
'*:page number:'
</code></pre>
</div>
<p>This describes three options: ‘<code>-l</code>’, ‘<code>-format</code>’, and ‘<code>-copy</code>’. The
first takes one argument described as ‘<code>left border</code>’ for which no
completion will be offered because of the empty action. Its argument may
come directly after the ‘<code>-l</code>’ or it may be given as the next word on
the line.</p>
<p>The ‘<code>-format</code>’ option takes one argument in the next word, described as
‘<code>paper size</code>’ for which only the strings ‘<code>letter</code>’ and ‘<code>A4</code>’ will be
completed.</p>
<p>The ‘<code>-copy</code>’ option may appear more than once on the command line and
takes two arguments. The first is mandatory and will be completed as a
filename. The second is optional (because of the second colon before the
description ‘<code>resolution</code>’) and will be completed from the strings
‘<code>300</code>’ and ‘<code>600</code>’.</p>
<p>The last two descriptions say what should be completed as arguments. The
first describes the first argument as a ‘<code>postscript file</code>’ and makes
files ending in ‘<code>ps</code>’ or ‘<code>eps</code>’ be completed. The last description
gives all other arguments the description ‘<code>page numbers</code>’ but does not
offer completions.</p>
<p><span id="index-_005fcache_005finvalid"></span></p>
<p><code>_cache_invalid</code> <code>cache_identifier</code></p>
<p>This function returns status zero if the completions cache corresponding
to the given cache identifier needs rebuilding. It determines this by
looking up the <code>cache-policy</code> style for the current context. This should
provide a function name which is run with the full path to the relevant
cache file as the only argument.</p>
<p>Example:</p>
<div class="example">
<pre><code class="language-example">_example_caching_policy () {
# rebuild if cache is more than a week old
local -a oldp
oldp=( &quot;$1&quot;(Nm+7) )
(( $#oldp ))
}
</code></pre>
</div>
<p><span id="index-_005fcall_005ffunction"></span></p>
<p><code>_call_function</code> <code>return</code> <code>name</code> [ <code>arg</code> ... ]</p>
<p>If a function <code>name</code> exists, it is called with the arguments <code>arg</code>s. The
<code>return</code> argument gives the name of a parameter in which the return
status from the function <code>name</code> should be stored; if <code>return</code> is empty
or a single hyphen it is ignored.</p>
<p>The return status of <code>_call_function</code> itself is zero if the function
<code>name</code> exists and was called and non-zero otherwise.</p>
<p><span id="index-_005fcall_005fprogram"></span></p>
<p><code>_call_program</code> [ <code>-l</code> ] [ <code>-p</code> ] <code>tag</code> <code>string</code> ...</p>
<p>This function provides a mechanism for the user to override the use of
an external command. It looks up the <code>command</code> style with the supplied
<code>tag</code>. If the style is set, its value is used as the command to execute.
The <code>string</code>s from the call to <code>_call_program</code>, or from the style if
set, are concatenated with spaces between them and the resulting string
is evaluated. The return status is the return status of the command
called.</p>
<p>By default, the command is run in an environment where all the locale
categories (except for <code>LC_CTYPE</code>) are reset to ‘<code>C</code>’ by calling the
utility function <code>_comp_locale</code> (see below). If the option ‘<code>-l</code>’ is
given, the command is run with the current locale.</p>
<p>If the option ‘<code>-p</code>’ is supplied it indicates that the command output is
influenced by the permissions it is run with. If the <code>gain-privileges</code>
style is set to true, <code>_call_program</code> will make use of commands such as
<code>sudo</code>, if present on the command-line, to match the permissions to
whatever the final command is likely to run under. When looking up the
<code>gain-privileges</code> and <code>command</code> styles, the command component of the
zstyle context will end with a slash (‘<code>/</code>’) followed by the command
that would be used to gain privileges.</p>
<p><span id="index-_005fcombination"></span></p>
<p><code>_combination</code> [ <code>-s</code> <code>pattern</code> ] <code>tag</code> <code>style</code> <code>spec</code> ... <code>field</code>
<code>opts</code> ...</p>
<p>This function is used to complete combinations of values, for example
pairs of hostnames and usernames. The <code>style</code> argument gives the style
which defines the pairs; it is looked up in a context with the <code>tag</code>
specified.</p>
<p>The style name consists of field names separated by hyphens, for example
‘<code>users-hosts-ports</code>’. For each field for a value is already known, a
<code>spec</code> of the form ‘<code>field``=``pattern</code>’ is given. For example, if the
command line so far specifies a user ‘<code>pws</code>’, the argument ‘<code>users=pws</code>’
should appear.</p>
<p>The next argument with no equals sign is taken as the name of the field
for which completions should be generated (presumably not one of the
<code>field</code>s for which the value is known).</p>
<p>The matches generated will be taken from the value of the style. These
should contain the possible values for the combinations in the
appropriate order (users, hosts, ports in the example above). The values
for the different fields are separated by colons. This can be altered
with the option <code>-s</code> to <code>_combination</code> which specifies a pattern.
Typically this is a character class, as for example ‘<code>-s &quot;[:@]&quot;</code>’ in the
case of the <code>users-hosts</code> style. Each ‘<code>field``=``pattern</code>’
specification restricts the completions which apply to elements of the
style with appropriately matching fields.</p>
<p>If no style with the given name is defined for the given tag, or if none
of the strings in style’s value match, but a function name of the
required field preceded by an underscore is defined, that function will
be called to generate the matches. For example, if there is no
‘<code>users-hosts-ports</code>’ or no matching hostname when a host is required,
the function ‘<code>_hosts</code>’ will automatically be called.</p>
<p>If the same name is used for more than one field, in both the
‘<code>field``=``pattern</code>’ and the argument that gives the name of the
field to be completed, the number of the field (starting with one) may
be given after the fieldname, separated from it by a colon.</p>
<p>All arguments after the required field name are passed to <code>compadd</code> when
generating matches from the style value, or to the functions for the
fields if they are called.</p>
<p><span id="index-_005fcommand_005fnames"></span></p>
<p><code>_command_names</code> [ <code>-e</code> | <code>-</code> ]</p>
<p>This function completes words that are valid at command position: names
of aliases, builtins, hashed commands, functions, and so on. With the
<code>-e</code> flag, only hashed commands are completed. The <code>-</code> flag is ignored.</p>
<p><span id="index-_005fcomp_005flocale"></span></p>
<p><code>_comp_locale</code></p>
<p>This function resets all the locale categories other than <code>LC_CTYPE</code> to
‘<code>C</code>’ so that the output from external commands can be easily analyzed
by the completion system. <code>LC_CTYPE</code> retains the current value (taking
<code>LC_ALL</code> and <code>LANG</code> into account), ensuring that non-ASCII characters in
file names are still handled properly.</p>
<p>This function should normally be run only in a subshell, because the new
locale is exported to the environment. Typical usage would be
‘<code> $(_comp_locale; ``command</code> ...<code>)</code>’.</p>
<p><span id="index-_005fcompleters"></span></p>
<p><code>_completers</code> [ <code>-p</code> ]</p>
<p>This function completes names of completers.</p>
<ul>
<li><code>-p</code><br />
Include the leading underscore (‘<code>_</code>’) in the matches.</li>
</ul>
<p><span id="index-_005fdescribe"></span></p>
<p><code>_describe </code>[<code>-12JVx</code>] [ <code>-oO</code> | <code>-t</code> <code>tag</code> ] <code>descr</code> <code>name1</code> [
<code>name2</code> ] [ <code>opt</code> ... ]</p>
<p><code>          </code>[ <code>-``-</code> <code>name1</code> [ <code>name2</code> ] [ <code>opt</code> ... ] ... ]</p>
<p>This function associates completions with descriptions. Multiple groups
separated by <code>-``-</code> can be supplied, potentially with different
completion options <code>opt</code>s.</p>
<p>The <code>descr</code> is taken as a string to display above the matches if the
<code>format</code> style for the <code>descriptions</code> tag is set. This is followed by
one or two names of arrays followed by options to pass to <code>compadd</code>. The
array <code>name1</code> contains the possible completions with their descriptions
in the form ‘<code>completion``:``description</code>’. Any literal colons in
<code>completion</code> must be quoted with a backslash. If a <code>name2</code> is given, it
should have the same number of elements as <code>name1</code>; in this case the
corresponding elements are added as possible completions instead of the
<code>completion</code> strings from <code>name1</code>. The completion list will retain the
descriptions from <code>name1</code>. Finally, a set of completion options can
appear.</p>
<p>If the option ‘<code>-o</code>’ appears before the first argument, the matches
added will be treated as names of command options (N.B. not shell
options), typically following a ‘<code>-</code>’, ‘<code>-``-</code>’ or ‘<code>+</code>’ on the command
line. In this case <code>_describe</code> uses the <code>prefix-hidden</code>, <code>prefix-needed</code>
and <code>verbose</code> styles to find out if the strings should be added as
completions and if the descriptions should be shown. Without the ‘<code>-o</code>’
option, only the <code>verbose</code> style is used to decide how descriptions are
shown. If ‘<code>-O</code>’ is used instead of ‘<code>-o</code>’, command options are
completed as above but <code>_describe</code> will not handle the <code>prefix-needed</code>
style.</p>
<p>With the <code>-t</code> option a <code>tag</code> can be specified. The default is ‘<code>values</code>’
or, if the <code>-o</code> option is given, ‘<code>options</code>’.</p>
<p>The options <code>-1</code>, <code>-2</code>, <code>-J</code>, <code>-V</code>, <code>-x</code> are passed to <code>_next_label</code>.</p>
<p>If selected by the <code>list-grouped</code> style, strings with the same
description will appear together in the list.</p>
<p><code>_describe</code> uses the <code>_all_labels</code> function to generate the matches, so
it does not need to appear inside a loop over tag labels.</p>
<p><span id="index-_005fdescription"></span></p>
<p><code>_description</code> [ <code>-x</code> ] [ <code>-12VJ</code> ] <code>tag</code> <code>name</code> <code>descr</code> [ <code>spec</code>
... ]</p>
<p>This function is not to be confused with the previous one; it is used as
a helper function for creating options to <code>compadd</code>. It is buried inside
many of the higher level completion functions and so often does not need
to be called directly.</p>
<p>The styles listed below are tested in the current context using the
given <code>tag</code>. The resulting options for <code>compadd</code> are put into the array
named <code>name</code> (this is traditionally ‘<code>expl</code>’, but this convention is not
enforced). The description for the corresponding set of matches is
passed to the function in <code>descr</code>.</p>
<p>The styles tested are: <code>format</code>, <code>hidden</code>, <code>matcher</code>, <code>ignore-line</code>,
<code>ignored-patterns</code>, <code>group-name</code> and <code>sort</code>. The <code>format</code> style is first
tested for the given <code>tag</code> and then for the <code>descriptions</code> tag if no
value was found, while the remainder are only tested for the tag given
as the first argument. The function also calls <code>_setup</code> which tests some
more styles.</p>
<p>The string returned by the <code>format</code> style (if any) will be modified so
that the sequence ‘<code>%d</code>’ is replaced by the <code>descr</code> given as the third
argument without any leading or trailing white space. If, after removing
the white space, the <code>descr</code> is the empty string, the format style will
not be used and the options put into the <code>name</code> array will not contain
an explanation string to be displayed above the matches.</p>
<p>If <code>_description</code> is called with more than three arguments, the
additional <code>spec</code>s should be of the form ‘<code>char``:``str</code>’. These supply
escape sequence replacements for the <code>format</code> style: every appearance of
‘<code>%``char</code>’ will be replaced by <code>string</code>.</p>
<p>If the <code>-x</code> option is given, the description will be passed to <code>compadd</code>
using the <code>-x</code> option instead of the default <code>-X</code>. This means that the
description will be displayed even if there are no corresponding
matches.</p>
<p>The options placed in the array <code>name</code> take account of the <code>group-name</code>
style, so matches are placed in a separate group where necessary. The
group normally has its elements sorted (by passing the option <code>-J</code> to
<code>compadd</code>), but if an option starting with ‘<code>-V</code>’, ‘<code>-J</code>’, ‘<code>-1</code>’, or
‘<code>-2</code>’ is passed to <code>_description</code>, that option will be included in
the array. Hence it is possible for the completion group to be unsorted
by giving the option ‘<code>-V</code>’, ‘<code>-1V</code>’, or ‘<code>-2V</code>’.</p>
<p>In most cases, the function will be used like this:</p>
<div class="example">
<pre><code class="language-example">local expl
_description files expl file
compadd &quot;$expl[@]&quot; - &quot;$files[@]&quot;
</code></pre>
</div>
<p>Note the use of the parameter <code>expl</code>, the hyphen, and the list of
matches. Almost all calls to <code>compadd</code> within the completion system use
a similar format; this ensures that user-specified styles are correctly
passed down to the builtins which implement the internals of completion.</p>
<p><span id="index-_005fdir_005flist"></span></p>
<p><code>_dir_list</code> [ <code>-s</code> <code>sep</code> ] [ <code>-S</code> ]</p>
<p>Complete a list of directory names separated by colons (the same format
as <code>$PATH</code>).</p>
<ul>
<li>
<p><code>-s</code> <code>sep</code><br />
Use <code>sep</code> as separator between items. <code>sep</code> defaults to a colon
(‘<code>:</code>’).</p>
</li>
<li>
<p><code>-S</code><br />
Add <code>sep</code> instead of slash (‘<code>/</code>’) as an autoremoveable suffix.</p>
</li>
</ul>
<p><span id="index-_005fdispatch"></span></p>
<p><code>_dispatch</code> <code>context string</code> ...</p>
<p>This sets the current context to <code>context</code> and looks for completion
functions to handle this context by hunting through the list of command
names or special contexts (as described above for <code>compdef</code>) given as
<code>string</code>s. The first completion function to be defined for one of the
contexts in the list is used to generate matches. Typically, the last
<code>string</code> is <code>-default-</code> to cause the function for default completion to
be used as a fallback.</p>
<p>The function sets the parameter <code>$service</code> to the <code>string</code> being tried,
and sets the <code>context/command</code> field (the fourth) of the <code>$curcontext</code>
parameter to the <code>context</code> given as the first argument.</p>
<p><span id="index-_005femail_005faddresses"></span></p>
<p><code>_email_addresses</code> [ <code>-c</code> ] [ <code>-n</code> <code>plugin</code> ]</p>
<p>Complete email addresses. Addresses are provided by plugins.</p>
<ul>
<li>
<p><code>-c</code><br />
Complete bare <code>localhost@domain.tld</code> addresses, without a name part
or a comment. Without this option, RFC822 ‘<code>Firstname Lastname</code>
<code>&lt;``address``&gt;</code>’ strings are completed.</p>
</li>
<li>
<p><code>-n</code> <code>plugin</code><br />
Complete aliases from <code>plugin</code>.</p>
</li>
</ul>
<p>The following plugins are available by default: <code>_email-ldap</code> (see the
<code>filter</code> style), <code>_email-local</code> (completes <code>user``@``hostname</code> Unix
addresses), <code>_email-mail</code> (completes aliases from <code>~/.mailrc</code>),
<code>_email-mush</code>, <code>_email-mutt</code>, and <code>_email-pine</code>.</p>
<p>Addresses from the <code>_email-``foo</code> plugin are added under the tag
‘<code>email-``foo</code>’.</p>
<p><em>Writing plugins</em></p>
<p>Plugins are written as separate functions with names starting with
‘<code>_email-</code>’. They are invoked with the <code>-c</code> option and <code>compadd</code>
options. They should either do their own completion or set the <code>$reply</code>
array to a list of ‘<code>alias``:``address</code>’ elements and return <code>300</code>. New
plugins will be picked up and run automatically.</p>
<p><span id="index-_005ffiles"></span></p>
<p><code>_files</code></p>
<p>The function <code>_files</code> is a wrapper around <code>_path_files</code>. It supports all
of the same functionality, with some enhancements — notably, it respects
the <code>list-dirs-first</code> style, and it allows users to override the
behaviour of the <code>-g</code> and <code>-/</code> options with the <code>file-patterns</code> style.
<code>_files</code> should therefore be preferred over <code>_path_files</code> in most cases.</p>
<p>This function accepts the full set of options allowed by <code>_path_files</code>,
described below.</p>
<p><span id="index-_005fgnu_005fgeneric"></span></p>
<p><code>_gnu_generic</code></p>
<p>This function is a simple wrapper around the <code>_arguments</code> function
described above. It can be used to determine automatically the long
options understood by commands that produce a list when passed the
option ‘<code>-``-help</code>’. It is intended to be used as a top-level completion
function in its own right. For example, to enable option completion for
the commands <code>foo</code> and <code>bar</code>, use</p>
<div class="example">
<pre><code class="language-example">compdef _gnu_generic foo bar
</code></pre>
</div>
<p>after the call to <code>compinit</code>.</p>
<p>The completion system as supplied is conservative in its use of this
function, since it is important to be sure the command understands the
option ‘<code>-``-help</code>’.</p>
<p><span id="index-_005fguard"></span></p>
<p><code>_guard</code> [ <code>options</code> ] <code>pattern descr</code></p>
<p>This function displays <code>descr</code> if <code>pattern</code> matches the string to be
completed. It is intended to be used in the <code>action</code> for the
specifications passed to <code>_arguments</code> and similar functions.</p>
<p>The return status is zero if the message was displayed and the word to
complete is not empty, and non-zero otherwise.</p>
<p>The <code>pattern</code> may be preceded by any of the options understood by
<code>compadd</code> that are passed down from <code>_description</code>, namely <code>-M</code>, <code>-J</code>,
<code>-V</code>, <code>-1</code>, <code>-2</code>, <code>-n</code>, <code>-F</code> and <code>-X</code>. All of these options will be
ignored. This fits in conveniently with the argument-passing conventions
of actions for <code>_arguments</code>.</p>
<p>As an example, consider a command taking the options <code>-n</code> and <code>-none</code>,
where <code>-n</code> must be followed by a numeric value in the same word. By
using:</p>
<div class="example">
<pre><code class="language-example">_arguments '-n-: :_guard &quot;[0-9]#&quot; &quot;numeric value&quot;' '-none'
</code></pre>
</div>
<p><code>_arguments</code> can be made to both display the message ‘<code>numeric value</code>’
and complete options after ‘<code>-n&lt;TAB&gt;</code>’. If the ‘<code>-n</code>’ is already
followed by one or more digits (the pattern passed to <code>_guard</code>) only the
message will be displayed; if the ‘<code>-n</code>’ is followed by another
character, only options are completed.</p>
<p><span id="index-_005fmessage"></span></p>
<p><code>_message</code> [ <code>-r12</code> ] [ <code>-VJ</code> <code>group</code> ] <code>descr</code></p>
<p><code>_message -e</code> [ <code>tag</code> ] <code>descr</code></p>
<p>The <code>descr</code> is used in the same way as the third argument to the
<code>_description</code> function, except that the resulting string will always be
shown whether or not matches were generated. This is useful for
displaying a help message in places where no completions can be
generated.</p>
<p>The <code>format</code> style is examined with the <code>messages</code> tag to find a
message; the usual tag, <code>descriptions</code>, is used only if the style is not
set with the former.</p>
<p>If the <code>-r</code> option is given, no style is used; the <code>descr</code> is taken
literally as the string to display. This is most useful when the <code>descr</code>
comes from a pre-processed argument list which already contains an
expanded description. Note that this option does not disable the
‘<code>%</code>’-sequence parsing done by <code>compadd</code>.</p>
<p>The <code>-12VJ</code> options and the <code>group</code> are passed to <code>compadd</code> and hence
determine the group the message string is added to.</p>
<p>The second <code>-e</code> form gives a description for completions with the tag
<code>tag</code> to be shown even if there are no matches for that tag. This form
is called by <code>_arguments</code> in the event that there is no action for an
option specification. The tag can be omitted and if so the tag is taken
from the parameter <code>$curtag</code>; this is maintained by the completion
system and so is usually correct. Note that if there are no matches at
the time this function is called, <code>compstate[insert]</code> is cleared, so
additional matches generated later are not inserted on the command line.</p>
<p><span id="index-_005fmulti_005fparts"></span></p>
<p><code>_multi_parts</code> [ <code>-i</code> ] <code>sep</code> <code>array</code></p>
<p>The argument <code>sep</code> is a separator character. The <code>array</code> may be either
the name of an array parameter or a literal array in the form ‘<code>(foo bar``)</code>’, a parenthesised list of words separated by whitespace. The
possible completions are the strings from the array. However, each chunk
delimited by <code>sep</code> will be completed separately. For example, the <code>_tar</code>
function uses ‘<code>_multi_parts</code> <code>/</code> <code>patharray</code>’ to complete partial file
paths from the given array of complete file paths.</p>
<p>The <code>-i</code> option causes <code>_multi_parts</code> to insert a unique match even if
that requires multiple separators to be inserted. This is not usually
the expected behaviour with filenames, but certain other types of
completion, for example those with a fixed set of possibilities, may be
more suited to this form.</p>
<p>Like other utility functions, this function accepts the ‘<code>-V</code>’, ‘<code>-J</code>’,
‘<code>-1</code>’, ‘<code>-2</code>’, ‘<code>-n</code>’, ‘<code>-f</code>’, ‘<code>-X</code>’, ‘<code>-M</code>’, ‘<code>-P</code>’, ‘<code>-S</code>’,
‘<code>-r</code>’, ‘<code>-R</code>’, and ‘<code>-q</code>’ options and passes them to the <code>compadd</code>
builtin.</p>
<p><span id="index-_005fnext_005flabel"></span></p>
<p><code>_next_label</code> [ <code>-x</code> ] [ <code>-12VJ</code> ] <code>tag</code> <code>name</code> <code>descr</code> [ <code>option</code>
... ]</p>
<p>This function is used to implement the loop over different tag labels
for a particular tag as described above for the <code>tag-order</code> style. On
each call it checks to see if there are any more tag labels; if there is
it returns status zero, otherwise non-zero. As this function requires a
current tag to be set, it must always follow a call to <code>_tags</code> or
<code>_requested</code>.</p>
<p>The <code>-x12VJ</code> options and the first three arguments are passed to the
<code>_description</code> function. Where appropriate the <code>tag</code> will be replaced by
a tag label in this call. Any description given in the <code>tag-order</code> style
is preferred to the <code>descr</code> passed to <code>_next_label</code>.</p>
<p>The <code>option</code>s given after the <code>descr</code> are set in the parameter given by
<code>name</code>, and hence are to be passed to <code>compadd</code> or whatever function is
called to add the matches.</p>
<p>Here is a typical use of this function for the tag <code>foo</code>. The call to
<code>_requested</code> determines if tag <code>foo</code> is required at all; the loop over
<code>_next_label</code> handles any labels defined for the tag in the <code>tag-order</code>
style.</p>
<div class="example">
<pre><code class="language-example">local expl ret=1
...
if _requested foo; then
...
while _next_label foo expl '...'; do
compadd &quot;$expl[@]&quot; ... &amp;&amp; ret=0
done
...
fi
return ret
</code></pre>
</div>
<p><span id="index-_005fnormal"></span></p>
<p><code>_normal</code> [ <code>-P</code> | <code>-p</code> <code>precommand</code> ]</p>
<p>This is the standard function called to handle completion outside any
special <code>-``context``-</code>. It is called both to complete the command word
and also the arguments for a command. In the second case, <code>_normal</code>
looks for a special completion for that command, and if there is none it
uses the completion for the <code>-default-</code> context.</p>
<p>A second use is to reexamine the command line specified by the <code>$words</code>
array and the <code>$CURRENT</code> parameter after those have been modified. For
example, the function <code>_precommand</code>, which completes after precommand
specifiers such as <code>nohup</code>, removes the first word from the <code>words</code>
array, decrements the <code>CURRENT</code> parameter, then calls ‘<code>_normal -p $service</code>’. The effect is that ‘<code>nohup</code> <code>cmd ...</code>’ is treated in the
same way as ‘<code>cmd ...</code>’.</p>
<ul>
<li>
<p><code>-P</code><br />
Reset the list of precommands. This option should be used if
completing a command line which allows internal commands (e.g.
builtins and functions) regardless of prior precommands (e.g. ‘<code>zsh -c</code>’).</p>
</li>
<li>
<p><code>-p</code> <code>precommand</code><br />
Append <code>precommand</code> to the list of precommands. This option should
be used in nearly all cases in which <code>-P</code> is not applicable.</p>
</li>
</ul>
<p>If the command name matches one of the patterns given by one of the
options <code>-p</code> or <code>-P</code> to <code>compdef</code>, the corresponding completion function
is called and then the parameter <code>_compskip</code> is checked. If it is set
completion is terminated at that point even if no matches have been
found. This is the same effect as in the <code>-first-</code> context.</p>
<p><span id="index-_005foptions"></span></p>
<p><code>_options</code></p>
<p>This can be used to complete the names of shell options. It provides a
matcher specification that ignores a leading ‘<code>no</code>’, ignores underscores
and allows upper-case letters to match their lower-case counterparts
(for example, ‘<code>glob</code>’, ‘<code>noglob</code>’, ‘<code>NO_GLOB</code>’ are all completed). Any
arguments are propagated to the <code>compadd</code> builtin.</p>
<p><span id="index-_005foptions_005fset"></span>
<span id="index-_005foptions_005funset"></span></p>
<p><code>_options_set</code> and <code>_options_unset</code></p>
<p>These functions complete only set or unset options, with the same
matching specification used in the <code>_options</code> function.</p>
<p>Note that you need to uncomment a few lines in the <code>_main_complete</code>
function for these functions to work properly. The lines in question are
used to store the option settings in effect before the completion widget
locally sets the options it needs. Hence these functions are not
generally used by the completion system.</p>
<p><span id="index-_005fparameters"></span></p>
<p><code>_parameters</code></p>
<p>This is used to complete the names of shell parameters.</p>
<p>The option ‘<code>-g</code> <code>pattern</code>’ limits the completion to parameters whose
type matches the <code>pattern</code>. The type of a parameter is that shown by
‘<code>print ${(t)``param``}</code>’, hence judicious use of ‘<code>*</code>’ in <code>pattern</code>
is probably necessary.</p>
<p>All other arguments are passed to the <code>compadd</code> builtin.</p>
<p><span id="index-_005fpath_005ffiles"></span></p>
<p><code>_path_files</code></p>
<p>This function is used throughout the completion system to complete
filenames. It allows completion of partial paths. For example, the
string ‘<code>/u/i/s/sig</code>’ may be completed to ‘<code>/usr/include/sys/signal.h</code>’.</p>
<p>The options accepted by both <code>_path_files</code> and <code>_files</code> are:</p>
<ul>
<li>
<p><code>-f</code><br />
Complete all filenames. This is the default.</p>
</li>
<li>
<p><code>-/</code><br />
Specifies that only directories should be completed.</p>
</li>
<li>
<p><code>-g</code> <code>pattern</code><br />
Specifies that only files matching the <code>pattern</code> should be
completed.</p>
</li>
<li>
<p><code>-W</code> <code>paths</code><br />
Specifies path prefixes that are to be prepended to the string from
the command line to generate the filenames but that should not be
inserted as completions nor shown in completion listings. Here,
<code>paths</code> may be the name of an array parameter, a literal list of
paths enclosed in parentheses or an absolute pathname.</p>
</li>
<li>
<p><code>-F</code> <code>ignored-files</code><br />
This behaves as for the corresponding option to the <code>compadd</code>
builtin. It gives direct control over which filenames should be
ignored. If the option is not present, the <code>ignored-patterns</code> style
is used.</p>
</li>
</ul>
<p>Both <code>_path_files</code> and <code>_files</code> also accept the following options which
are passed to <code>compadd</code>: ‘<code>-J</code>’, ‘<code>-V</code>’, ‘<code>-1</code>’, ‘<code>-2</code>’, ‘<code>-n</code>’, ‘<code>-X</code>’,
‘<code>-M</code>’, ‘<code>-P</code>’, ‘<code>-S</code>’, ‘<code>-q</code>’, ‘<code>-r</code>’, and ‘<code>-R</code>’.</p>
<p>Finally, the <code>_path_files</code> function uses the styles <code>expand</code>,
<code>ambiguous</code>, <code>special-dirs</code>, <code>list-suffixes</code> and <code>file-sort</code> described
above.</p>
<p><span id="index-_005fpick_005fvariant"></span></p>
<p><code>_pick_variant </code>[ <code>-b</code> <code>builtin-label</code> ] [ <code>-c</code> <code>command</code> ] [
<code>-r</code> <code>name</code> ]</p>
<p><code>              ``label``=``pattern</code> ... <code>label</code> [ <code>arg</code> ... ]</p>
<p>This function is used to resolve situations where a single command name
requires more than one type of handling, either because it has more than
one variant or because there is a name clash between two different
commands.</p>
<p>The command to run is taken from the first element of the array <code>words</code>
unless this is overridden by the option <code>-c</code>. This command is run and
its output is compared with a series of patterns. Arguments to be passed
to the command can be specified at the end after all the other
arguments. The patterns to try in order are given by the arguments
<code>label``=``pattern</code>; if the output of ‘<code>command</code> <code>arg</code> ...’ contains
<code>pattern</code>, then <code>label</code> is selected as the label for the command
variant. If none of the patterns match, the final command label is
selected and status 1 is returned.</p>
<p>If the ‘<code>-b</code> <code>builtin-label</code>’ is given, the command is tested to see if
it is provided as a shell builtin, possibly autoloaded; if so, the label
<code>builtin-label</code> is selected as the label for the variant.</p>
<p>If the ‘<code>-r</code> <code>name</code>’ is given, the <code>label</code> picked is stored in the
parameter named <code>name</code>.</p>
<p>The results are also cached in the <code>_cmd_variant</code> associative array
indexed by the name of the command run.</p>
<p><span id="index-_005fregex_005farguments"></span></p>
<p><code>_regex_arguments</code> <code>name</code> <code>spec</code> ...</p>
<p>This function generates a completion function <code>name</code> which matches the
specifications <code>spec</code>s, a set of regular expressions as described below.
After running <code>_regex_arguments</code>, the function <code>name</code> should be called
as a normal completion function. The pattern to be matched is given by
the contents of the <code>words</code> array up to the current cursor position
joined together with null characters; no quotation is applied.</p>
<p>The arguments are grouped as sets of alternatives separated by ‘<code>|</code>’,
which are tried one after the other until one matches. Each alternative
consists of a one or more specifications which are tried left to right,
with each pattern matched being stripped in turn from the command line
being tested, until all of the group succeeds or until one fails; in the
latter case, the next alternative is tried. This structure can be
repeated to arbitrary depth by using parentheses; matching proceeds from
inside to outside.</p>
<p>A special procedure is applied if no test succeeds but the remaining
command line string contains no null character (implying the remaining
word is the one for which completions are to be generated). The
completion target is restricted to the remaining word and any <code>action</code>s
for the corresponding patterns are executed. In this case, nothing is
stripped from the command line string. The order of evaluation of the
<code>action</code>s can be determined by the <code>tag-order</code> style; the various
formats supported by <code>_alternative</code> can be used in <code>action</code>. The <code>descr</code>
is used for setting up the array parameter <code>expl</code>.</p>
<p>Specification arguments take one of following forms, in which
metacharacters such as ‘<code>(</code>’, ‘<code>)</code>’, ‘<code>#</code>’ and ‘<code>|</code>’ should be quoted.</p>
<ul>
<li>
<p><code>/``pattern``/</code> [<code>%``lookahead``%</code>] [<code>-``guard</code>]
[<code>:``tag``:``descr``:``action</code>]<br />
This is a single primitive component. The function tests whether the
combined pattern ‘<code>(#b)((#B)``pattern``)``lookahead``*</code>’ matches the
command line string. If so, ‘<code>guard</code>’ is evaluated and its return
status is examined to determine if the test has succeeded. The
<code>pattern</code> string ‘<code>[]</code>’ is guaranteed never to match. The
<code>lookahead</code> is not stripped from the command line before the next
pattern is examined.</p>
<p>The argument starting with <code>:</code> is used in the same manner as an
argument to <code>_alternative</code>.</p>
<p>A component is used as follows: <code>pattern</code> is tested to see if the
component already exists on the command line. If it does, any
following specifications are examined to find something to complete.
If a component is reached but no such pattern exists yet on the
command line, the string containing the <code>action</code> is used to generate
matches to insert at that point.</p>
</li>
<li>
<p><code>/``pattern``/+</code> [<code>%``lookahead``%</code>] [<code>-``guard</code>]
[<code>:``tag``:``descr``:``action</code>]<br />
This is similar to ‘<code>/``pattern``/</code> ...’ but the left part of the
command line string (i.e. the part already matched by previous
patterns) is also considered part of the completion target.</p>
</li>
<li>
<p><code>/``pattern``/-</code> [<code>%``lookahead``%</code>] [<code>-``guard</code>]
[<code>:``tag``:``descr``:``action</code>]<br />
This is similar to ‘<code>/``pattern``/</code> ...’ but the <code>action</code>s of the
current and previously matched patterns are ignored even if the
following ‘<code>pattern</code>’ matches the empty string.</p>
</li>
<li>
<p><code>(</code> <code>spec</code> <code>)</code><br />
Parentheses may be used to groups <code>spec</code>s; note each parenthesis is
a single argument to <code>_regex_arguments</code>.</p>
</li>
<li>
<p><code>spec</code> <code>#</code><br />
This allows any number of repetitions of <code>spec</code>.</p>
</li>
<li>
<p><code>spec</code> <code>spec</code><br />
The two <code>spec</code>s are to be matched one after the other as described
above.</p>
</li>
<li>
<p><code>spec</code> <code>|</code> <code>spec</code><br />
Either of the two <code>spec</code>s can be matched.</p>
</li>
</ul>
<p>The function <code>_regex_words</code> can be used as a helper function to generate
matches for a set of alternative words possibly with their own arguments
as a command line argument.</p>
<p>Examples:</p>
<div class="example">
<pre><code class="language-example">_regex_arguments _tst /$'[^\0]#\0'/ \
/$'[^\0]#\0'/ :'compadd aaa'
</code></pre>
</div>
<p>This generates a function <code>_tst</code> that completes <code>aaa</code> as its only
argument. The <code>tag</code> and <code>description</code> for the action have been omitted
for brevity (this works but is not recommended in normal use). The first
component matches the command word, which is arbitrary; the second
matches any argument. As the argument is also arbitrary, any following
component would not depend on <code>aaa</code> being present.</p>
<div class="example">
<pre><code class="language-example">_regex_arguments _tst /$'[^\0]#\0'/ \
/$'aaa\0'/ :'compadd aaa'
</code></pre>
</div>
<p>This is a more typical use; it is similar, but any following patterns
would only match if <code>aaa</code> was present as the first argument.</p>
<div class="example">
<pre><code class="language-example">_regex_arguments _tst /$'[^\0]#\0'/ \( \
/$'aaa\0'/ :'compadd aaa' \
/$'bbb\0'/ :'compadd bbb' \) \#
</code></pre>
</div>
<p>In this example, an indefinite number of command arguments may be
completed. Odd arguments are completed as <code>aaa</code> and even arguments as
<code>bbb</code>. Completion fails unless the set of <code>aaa</code> and <code>bbb</code> arguments
before the current one is matched correctly.</p>
<div class="example">
<pre><code class="language-example">_regex_arguments _tst /$'[^\0]#\0'/ \
\( /$'aaa\0'/ :'compadd aaa' \| \
/$'bbb\0'/ :'compadd bbb' \) \#
</code></pre>
</div>
<p>This is similar, but either <code>aaa</code> or <code>bbb</code> may be completed for any
argument. In this case <code>_regex_words</code> could be used to generate</p>
<p><span id="index-_005fregex_005fwords-_005b-_002dt-term-_005d"></span></p>
<p><code>_regex_words</code> <code>tag</code> <code>description</code> <code>spec</code> ...</p>
<p>This function can be used to generate arguments for the
<code>_regex_arguments</code> command which may be inserted at any point where a
set of rules is expected. The <code>tag</code> and <code>description</code> give a standard
tag and description pertaining to the current context. Each <code>spec</code>
contains two or three arguments separated by a colon: note that there is
no leading colon in this case.</p>
<p>Each <code>spec</code> gives one of a set of words that may be completed at this
point, together with arguments. It is thus roughly equivalent to the
<code>_arguments</code> function when used in normal (non-regex) completion.</p>
<p>The part of the <code>spec</code> before the first colon is the word to be
completed. This may contain a <code>*</code>; the entire word, before and after the
<code>*</code> is completed, but only the text before the <code>*</code> is required for the
context to be matched, so that further arguments may be completed after
the abbreviated form.</p>
<p>The second part of <code>spec</code> is a description for the word being completed.</p>
<p>The optional third part of the <code>spec</code> describes how words following the
one being completed are themselves to be completed. It will be evaluated
in order to avoid problems with quoting. This means that typically it
contains a reference to an array containing previously generated regex
arguments.</p>
<p>The option <code>-t</code> <code>term</code> specifies a terminator for the word instead of
the usual space. This is handled as an auto-removable suffix in the
manner of the option <code>-s</code> <code>sep</code> to <code>_values</code>.</p>
<p>The result of the processing by <code>_regex_words</code> is placed in the array
<code>reply</code>, which should be made local to the calling function. If the set
of words and arguments may be matched repeatedly, a <code>#</code> should be
appended to the generated array at that point.</p>
<p>For example:</p>
<div class="example">
<pre><code class="language-example">local -a reply
_regex_words mydb-commands 'mydb commands' \
'add:add an entry to mydb:$mydb_add_cmds' \
'show:show entries in mydb'
_regex_arguments _mydb &quot;$reply[@]&quot;
_mydb &quot;$@&quot;
</code></pre>
</div>
<p>This shows a completion function for a command <code>mydb</code> which takes two
command arguments, <code>add</code> and <code>show</code>. <code>show</code> takes no arguments, while
the arguments for <code>add</code> have already been prepared in an array
<code>mydb_add_cmds</code>, quite possibly by a previous call to <code>_regex_words</code>.</p>
<p><span id="index-_005frequested"></span></p>
<p><code>_requested</code> [ <code>-x</code> ] [ <code>-12VJ</code> ] <code>tag</code> [ <code>name</code> <code>descr</code> [
<code>command</code> [ <code>arg</code> ... ] ]</p>
<p>This function is called to decide whether a tag already registered by a
call to <code>_tags</code> (see below) has been requested by the user and hence
completion should be performed for it. It returns status zero if the tag
is requested and non-zero otherwise. The function is typically used as
part of a loop over different tags as follows:</p>
<div class="example">
<pre><code class="language-example">_tags foo bar baz
while _tags; do
if _requested foo; then
... # perform completion for foo
fi
... # test the tags bar and baz in the same way
... # exit loop if matches were generated
done
</code></pre>
</div>
<p>Note that the test for whether matches were generated is not performed
until the end of the <code>_tags</code> loop. This is so that the user can set the
<code>tag-order</code> style to specify a set of tags to be completed at the same
time.</p>
<p>If <code>name</code> and <code>descr</code> are given, <code>_requested</code> calls the <code>_description</code>
function with these arguments together with the options passed to
<code>_requested</code>.</p>
<p>If <code>command</code> is given, the <code>_all_labels</code> function will be called
immediately with the same arguments. In simple cases this makes it
possible to perform the test for the tag and the matching in one go. For
example:</p>
<div class="example">
<pre><code class="language-example">local expl ret=1
_tags foo bar baz
while _tags; do
_requested foo expl 'description' \
compadd foobar foobaz &amp;&amp; ret=0
...
(( ret )) || break
done
</code></pre>
</div>
<p>If the <code>command</code> is not <code>compadd</code>, it must nevertheless be prepared to
handle the same options.</p>
<p><span id="index-_005fretrieve_005fcache"></span></p>
<p><code>_retrieve_cache</code> <code>cache_identifier</code></p>
<p>This function retrieves completion information from the file given by
<code>cache_identifier</code>, stored in a directory specified by the <code>cache-path</code>
style which defaults to <code>~/.zcompcache</code>. The return status is zero if
retrieval was successful. It will only attempt retrieval if the
<code>use-cache</code> style is set, so you can call this function without worrying
about whether the user wanted to use the caching layer.</p>
<p>See <code>_store_cache</code> below for more details.</p>
<p><span id="index-_005fsep_005fparts"></span></p>
<p><code>_sep_parts</code></p>
<p>This function is passed alternating arrays and separators as arguments.
The arrays specify completions for parts of strings to be separated by
the separators. The arrays may be the names of array parameters or a
quoted list of words in parentheses. For example, with the array
‘<code>hosts=(ftp news)</code>’ the call ‘<code>_sep_parts ’(foo bar)’ @ hosts</code>’ will
complete the string ‘<code>f</code>’ to ‘<code>foo</code>’ and the string ‘<code>b@n</code>’ to
‘<code>bar@news</code>’.</p>
<p>This function accepts the <code>compadd</code> options ‘<code>-V</code>’, ‘<code>-J</code>’, ‘<code>-1</code>’,
‘<code>-2</code>’, ‘<code>-n</code>’, ‘<code>-X</code>’, ‘<code>-M</code>’, ‘<code>-P</code>’, ‘<code>-S</code>’, ‘<code>-r</code>’, ‘<code>-R</code>’, and
‘<code>-q</code>’ and passes them on to the <code>compadd</code> builtin used to add the
matches.</p>
<p><span id="index-_005fsequence"></span></p>
<p><code>_sequence</code> [ <code>-s</code> <code>sep</code> ] [ <code>-n</code> <code>max</code> ] [ <code>-d</code> ] <code>function</code> [
<code>-</code> ] ...</p>
<p>This function is a wrapper to other functions for completing items in a
separated list. The same function is used to complete each item in the
list. The separator is specified with the <code>-s</code> option. If <code>-s</code> is
omitted it will use ‘<code>,</code>’. Duplicate values are not matched unless <code>-d</code>
is specified. If there is a fixed or maximum number of items in the
list, this can be specified with the <code>-n</code> option.</p>
<p>Common <code>compadd</code> options are passed on to the function. It is possible
to use <code>compadd</code> directly with <code>_sequence</code>, though <code>_values</code> may be more
appropriate in this situation.</p>
<p><span id="index-_005fsetup"></span></p>
<p><code>_setup</code> <code>tag</code> [ <code>group</code> ]</p>
<p>This function sets up the special parameters used by the completion
system appropriately for the <code>tag</code> given as the first argument. It uses
the styles <code>list-colors</code>, <code>list-packed</code>, <code>list-rows-first</code>,
<code>last-prompt</code>, <code>accept-exact</code>, <code>menu</code> and <code>force-list</code>.</p>
<p>The optional <code>group</code> supplies the name of the group in which the matches
will be placed. If it is not given, the <code>tag</code> is used as the group name.</p>
<p>This function is called automatically from <code>_description</code> and hence is
not normally called explicitly.</p>
<p><span id="index-_005fstore_005fcache"></span></p>
<p><code>_store_cache</code> <code>cache_identifier</code> <code>param</code> ...</p>
<p>This function, together with <code>_retrieve_cache</code> and <code>_cache_invalid</code>,
implements a caching layer which can be used in any completion function.
Data obtained by costly operations are stored in parameters; this
function then dumps the values of those parameters to a file. The data
can then be retrieved quickly from that file via <code>_retrieve_cache</code>, even
in different instances of the shell.</p>
<p>The <code>cache_identifier</code> specifies the file which the data should be
dumped to. The file is stored in a directory specified by the
<code>cache-path</code> style which defaults to <code>~/.zcompcache</code>. The remaining
<code>param</code>s arguments are the parameters to dump to the file.</p>
<p>The return status is zero if storage was successful. The function will
only attempt storage if the <code>use-cache</code> style is set, so you can call
this function without worrying about whether the user wanted to use the
caching layer.</p>
<p>The completion function may avoid calling <code>_retrieve_cache</code> when it
already has the completion data available as parameters. However, in
that case it should call <code>_cache_invalid</code> to check whether the data in
the parameters and in the cache are still valid.</p>
<p>See the _perl_modules completion function for a simple example of the
usage of the caching layer.</p>
<p><span id="index-_005ftags"></span></p>
<p><code>_tags</code> [ [ <code>-C</code> <code>name</code> ] <code>tag</code> ... ]</p>
<p>If called with arguments, these are taken to be the names of tags valid
for completions in the current context. These tags are stored internally
and sorted by using the <code>tag-order</code> style.</p>
<p>Next, <code>_tags</code> is called repeatedly without arguments from the same
completion function. This successively selects the first, second, etc.
set of tags requested by the user. The return status is zero if at least
one of the tags is requested and non-zero otherwise. To test if a
particular tag is to be tried, the <code>_requested</code> function should be
called (see above).</p>
<p>If ‘<code>-C</code> <code>name</code>’ is given, <code>name</code> is temporarily stored in the
<code>argument</code> field (the fifth) of the context in the <code>curcontext</code>
parameter during the call to <code>_tags</code>; the field is restored on exit.
This allows <code>_tags</code> to use a more specific context without having to
change and reset the <code>curcontext</code> parameter (which has the same effect).</p>
<p><span id="index-_005ftilde_005ffiles"></span></p>
<p><code>_tilde_files</code></p>
<p>Like <code>_files</code>, but resolve leading tildes according to the rules of
filename expansion, so the suggested completions don’t start with a
‘<code>~</code>’ even if the filename on the command-line does.</p>
<p><span id="index-_005fvalues"></span></p>
<p><code>_values</code> [ <code>-O</code> <code>name</code> ] [ <code>-s</code> <code>sep</code> ] [ <code>-S</code> <code>sep</code> ] [ <code>-wC</code>
] <code>desc</code> <code>spec</code> ...</p>
<p>This is used to complete arbitrary keywords (values) and their
arguments, or lists of such combinations.</p>
<p>If the first argument is the option ‘<code>-O</code> <code>name</code>’, it will be used in
the same way as by the <code>_arguments</code> function. In other words, the
elements of the <code>name</code> array will be passed to <code>compadd</code> when executing
an action.</p>
<p>If the first argument (or the first argument after ‘<code>-O</code> <code>name</code>’) is
‘<code>-s</code>’, the next argument is used as the character that separates
multiple values. This character is automatically added after each value
in an auto-removable fashion (see below); all values completed by
‘<code>_values -s</code>’ appear in the same word on the command line, unlike
completion using <code>_arguments</code>. If this option is not present, only a
single value will be completed per word.</p>
<p>Normally, <code>_values</code> will only use the current word to determine which
values are already present on the command line and hence are not to be
completed again. If the <code>-w</code> option is given, other arguments are
examined as well.</p>
<p>The first non-option argument, <code>desc</code>, is used as a string to print as a
description before listing the values.</p>
<p>All other arguments describe the possible values and their arguments in
the same format used for the description of options by the <code>_arguments</code>
function (see above). The only differences are that no minus or plus
sign is required at the beginning, values can have only one argument,
and the forms of action beginning with an equal sign are not supported.</p>
<p>The character separating a value from its argument can be set using the
option <code>-S</code> (like <code>-s</code>, followed by the character to use as the
separator in the next argument). By default the equals sign will be used
as the separator between values and arguments.</p>
<p>Example:</p>
<div class="example">
<pre><code class="language-example">_values -s , 'description' \
'*foo[bar]' \
'(two)*one[number]:first count:' \
'two[another number]::second count:(1 2 3)'
</code></pre>
</div>
<p>This describes three possible values: ‘<code>foo</code>’, ‘<code>one</code>’, and ‘<code>two</code>’. The
first is described as ‘<code>bar</code>’, takes no argument and may appear more
than once. The second is described as ‘<code>number</code>’, may appear more than
once, and takes one mandatory argument described as ‘<code>first count</code>’; no
action is specified, so it will not be completed. The ‘<code>(two)</code>’ at the
beginning says that if the value ‘<code>one</code>’ is on the line, the value
‘<code>two</code>’ will no longer be considered a possible completion. Finally,
the last value (‘<code>two</code>’) is described as ‘<code>another number</code>’ and takes an
optional argument described as ‘<code>second count</code>’ for which the
completions (to appear after an ‘<code>=</code>’) are ‘<code>1</code>’, ‘<code>2</code>’, and ‘<code>3</code>’. The
<code>_values</code> function will complete lists of these values separated by
commas.</p>
<p>Like <code>_arguments</code>, this function temporarily adds another context name
component to the arguments element (the fifth) of the current context
while executing the <code>action</code>. Here this name is just the name of the
value for which the argument is completed.</p>
<p>The style <code>verbose</code> is used to decide if the descriptions for the values
(but not those for the arguments) should be printed.</p>
<p>The associative array <code>val_args</code> is used to report values and their
arguments; this works similarly to the <code>opt_args</code> associative array used
by <code>_arguments</code>. Hence the function calling <code>_values</code> should declare the
local parameters <code>state</code>, <code>state_descr</code>, <code>line</code>, <code>context</code> and
<code>val_args</code>:</p>
<div class="example">
<pre><code class="language-example">local context state state_descr line
typeset -A val_args
</code></pre>
</div>
<p>when using an action of the form ‘<code>-&gt;``string</code>’. With this function the
<code>context</code> parameter will be set to the name of the value whose argument
is to be completed. Note that for <code>_values</code>, the <code>state</code> and
<code>state_descr</code> are scalars rather than arrays. Only a single matching
state is returned.</p>
<p>Note also that <code>_values</code> normally adds the character used as the
separator between values as an auto-removable suffix (similar to a ‘<code>/</code>’
after a directory). However, this is not possible for a ‘<code>-&gt;``string</code>’
action as the matches for the argument are generated by the calling
function. To get the usual behaviour, the calling function can add the
separator <code>x</code> as a suffix by passing the options ‘<code>-qS</code> <code>x</code>’ either
directly or indirectly to <code>compadd</code>.</p>
<p>The option <code>-C</code> is treated in the same way as it is by <code>_arguments</code>. In
that case the parameter <code>curcontext</code> should be made local instead of
<code>context</code> (as described above).</p>
<p><span id="index-_005fwanted"></span></p>
<p><code>_wanted</code> [ <code>-x</code> ] [ <code>-C</code> <code>name</code> ] [ <code>-12VJ</code> ] <code>tag</code> <code>name</code>
<code>descr</code> <code>command</code> [ <code>arg</code> ...]</p>
<p>In many contexts, completion can only generate one particular set of
matches, usually corresponding to a single tag. However, it is still
necessary to decide whether the user requires matches of this type. This
function is useful in such a case.</p>
<p>The arguments to <code>_wanted</code> are the same as those to <code>_requested</code>, i.e.
arguments to be passed to <code>_description</code>. However, in this case the
<code>command</code> is not optional; all the processing of tags, including the
loop over both tags and tag labels and the generation of matches, is
carried out automatically by <code>_wanted</code>.</p>
<p>Hence to offer only one tag and immediately add the corresponding
matches with the given description:</p>
<div class="example">
<pre><code class="language-example">local expl
_wanted tag expl 'description' \
compadd matches...
</code></pre>
</div>
<p>Note that, as for <code>_requested</code>, the <code>command</code> must be able to accept
options to be passed down to <code>compadd</code>.</p>
<p>Like <code>_tags</code> this function supports the <code>-C</code> option to give a different
name for the argument context field. The <code>-x</code> option has the same
meaning as for <code>_description</code>.</p>
<p><span id="index-_005fwidgets"></span></p>
<p><code>_widgets</code> [ <code>-g</code> <code>pattern</code> ]</p>
<p>This function completes names of zle widgets (see
<a href="Zsh-Line-Editor.html#Zle-Widgets">Widgets</a>). The <code>pattern</code>, if present,
is matched against values of the <code>$widgets</code> special parameter,
documented in <a href="Zsh-Modules.html#The-zsh_002fzleparameter-Module">The zsh/zleparameter
Module</a>.</p>
<hr />
<p><span id="Completion-System-Variables"></span>
<span id="Completion-System-Variables-1"></span></p>
<h2 id="207-completion-system-variables"><a class="header" href="#207-completion-system-variables">20.7 Completion System Variables</a></h2>
<p><span id="index-completion-system_002c-variables"></span></p>
<p>There are some standard variables, initialised by the <code>_main_complete</code>
function and then used from other functions.</p>
<p>The standard variables are:</p>
<ul>
<li>
<p><code>_comp_caller_options</code><br />
The completion system uses <code>setopt</code> to set a number of options. This
allows functions to be written without concern for compatibility
with every possible combination of user options. However, sometimes
completion needs to know what the user’s option preferences are.
These are saved in the <code>_comp_caller_options</code> associative array.
Option names, spelled in lowercase without underscores, are mapped
to one or other of the strings ‘<code>on</code>’ and ‘<code>off</code>’.</p>
</li>
<li>
<p><code>_comp_priv_prefix</code><br />
Completion functions such as <code>_sudo</code> can set the <code>_comp_priv_prefix</code>
array to a command prefix that may then be used by <code>_call_program</code>
to match the privileges when calling programs to generate matches.</p>
</li>
</ul>
<p>Two more features are offered by the <code>_main_complete</code> function. The
arrays <code>compprefuncs</code> and <code>comppostfuncs</code> may contain names of functions
that are to be called immediately before or after completion has been
tried. A function will only be called once unless it explicitly
reinserts itself into the array.</p>
<hr />
<p><span id="Completion-Directories"></span>
<span id="Completion-Directories-1"></span></p>
<h2 id="208-completion-directories"><a class="header" href="#208-completion-directories">20.8 Completion Directories</a></h2>
<p><span id="index-completion-system_002c-directory-structure"></span></p>
<p>In the source distribution, the files are contained in various
subdirectories of the <code>Completion</code> directory. They may have been
installed in the same structure, or into one single function directory.
The following is a description of the files found in the original
directory structure. If you wish to alter an installed file, you will
need to copy it to some directory which appears earlier in your <code>fpath</code>
than the standard directory where it appears.</p>
<ul>
<li>
<p><code>Base</code><br />
The core functions and special completion widgets automatically
bound to keys. You will certainly need most of these, though will
probably not need to alter them. Many of these are documented above.</p>
</li>
<li>
<p><code>Zsh</code><br />
Functions for completing arguments of shell builtin commands and
utility functions for this. Some of these are also used by functions
from the <code>Unix</code> directory.</p>
</li>
<li>
<p><code>Unix</code><br />
Functions for completing arguments of external commands and suites
of commands. They may need modifying for your system, although in
many cases some attempt is made to decide which version of a command
is present. For example, completion for the <code>mount</code> command tries to
determine the system it is running on, while completion for many
other utilities try to decide whether the GNU version of the command
is in use, and hence whether the <code>-``-help</code> option is supported.</p>
</li>
<li>
<p><code>X</code>, <code>AIX</code>, <code>BSD</code>, ...<br />
Completion and utility function for commands available only on some
systems. These are not arranged hierarchically, so, for example,
both the <code>Linux</code> and <code>Debian</code> directories, as well as the <code>X</code>
directory, may be useful on your system.</p>
</li>
</ul>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Completion-Using-compctl.html#21-completion-using-compctl">21 Completion Using compctl</a>
<ul>
<li><a href="Completion-Using-compctl.html#211-types-of-completion">21.1 Types of completion</a></li>
<li><a href="Completion-Using-compctl.html#212-description">21.2 Description</a></li>
<li><a href="Completion-Using-compctl.html#213-command-flags">21.3 Command Flags</a></li>
<li><a href="Completion-Using-compctl.html#214-option-flags">21.4 Option Flags</a>
<ul>
<li><a href="Completion-Using-compctl.html#2141-simple-flags">21.4.1 Simple Flags</a></li>
<li><a href="Completion-Using-compctl.html#2142-flags-with-arguments">21.4.2 Flags with Arguments</a></li>
<li><a href="Completion-Using-compctl.html#2143-control-flags">21.4.3 Control Flags</a></li>
</ul>
</li>
<li><a href="Completion-Using-compctl.html#215-alternative-completion">21.5 Alternative Completion</a></li>
<li><a href="Completion-Using-compctl.html#216-extended-completion">21.6 Extended Completion</a></li>
<li><a href="Completion-Using-compctl.html#217-example">21.7 Example</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Completion-Using-compctl"></span>
<span id="Completion-Using-compctl-1"></span></p>
<h1 id="21-completion-using-compctl"><a class="header" href="#21-completion-using-compctl">21 Completion Using compctl</a></h1>
<p><span id="index-completion_002c-programmable-2"></span>
<span id="index-completion_002c-controlling-2"></span></p>
<hr />
<p><span id="Types-of-completion"></span></p>
<h2 id="211-types-of-completion"><a class="header" href="#211-types-of-completion">21.1 Types of completion</a></h2>
<p>This version of zsh has two ways of performing completion of words on
the command line. New users of the shell may prefer to use the newer and
more powerful system based on shell functions; this is described in
<a href="Completion-System.html#Completion-System">Completion System</a>, and the
basic shell mechanisms which support it are described in <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a>. This chapter
describes the older <code>compctl</code> command.</p>
<hr />
<p><span id="Description-7"></span></p>
<h2 id="212-description"><a class="header" href="#212-description">21.2 Description</a></h2>
<p><span id="index-compctl"></span></p>
<p><code>compctl</code> [ <code>-CDT</code> ] <code>options</code> [ <code>command</code> ... ]</p>
<p><code>compctl </code>[ <code>-CDT</code> ] <code>options</code> [ <code>-x</code> <code>pattern</code> <code>options</code> <code>-</code> ...
<code>-``-</code> ]</p>
<p><code>        </code>[ <code>+</code> <code>options</code> [ <code>-x</code> ... <code>-``-</code> ] ... [<code>+</code>] ] [
<code>command</code> ... ]</p>
<p><code>compctl</code> <code>-M</code> <code>match-specs</code> ...</p>
<p><code>compctl</code> <code>-L</code> [ <code>-CDTM</code> ] [ <code>command</code> ... ]</p>
<p><code>compctl</code> <code>+</code> <code>command</code> ...</p>
<p>Control the editor’s completion behavior according to the supplied set
of <code>options</code>. Various editing commands, notably
<code>expand-or-complete-word</code>, usually bound to tab, will attempt to
complete a word typed by the user, while others, notably
<code>delete-char-or-list</code>, usually bound to ^D in EMACS editing mode, list
the possibilities; <code>compctl</code> controls what those possibilities are. They
may for example be filenames (the most common case, and hence the
default), shell variables, or words from a user-specified list.</p>
<hr />
<p><span id="Command-Flags"></span> <span id="Command-Flags-1"></span></p>
<h2 id="213-command-flags"><a class="header" href="#213-command-flags">21.3 Command Flags</a></h2>
<p>Completion of the arguments of a command may be different for each
command or may use the default. The behavior when completing the command
word itself may also be separately specified. These correspond to the
following flags and arguments, all of which (except for <code>-L</code>) may be
combined with any combination of the <code>options</code> described subsequently in
<a href="Completion-Using-compctl.html#Option-Flags">Option Flags</a>:</p>
<ul>
<li>
<p><code>command</code> ...<br />
controls completion for the named commands, which must be listed
last on the command line. If completion is attempted for a command
with a pathname containing slashes and no completion definition is
found, the search is retried with the last pathname component. If
the command starts with a <code>=</code>, completion is tried with the pathname
of the command.</p>
<p>Any of the <code>command</code> strings may be patterns of the form normally
used for filename generation. These should be quoted to protect them
from immediate expansion; for example the command string <code>’foo*’</code>
arranges for completion of the words of any command beginning with
<code>foo</code>. When completion is attempted, all pattern completions are
tried in the reverse order of their definition until one matches. By
default, completion then proceeds as normal, i.e. the shell will try
to generate more matches for the specific command on the command
line; this can be overridden by including <code>-tn</code> in the flags for the
pattern completion.</p>
<p>Note that aliases are expanded before the command name is determined
unless the <code>COMPLETE_ALIASES</code> option is set. Commands may not be
combined with the <code>-C</code>, <code>-D</code> or <code>-T</code> flags.</p>
</li>
<li>
<p><code>-C</code><br />
controls completion when the command word itself is being completed.
If no <code>compctl -C</code> command has been issued, the names of any as
aliases or functions) are completed.</p>
</li>
<li>
<p><code>-D</code><br />
controls default completion behavior for the arguments of commands
not assigned any special behavior. If no <code>compctl -D</code> command has
been issued, filenames are completed.</p>
</li>
<li>
<p><code>-T</code><br />
supplies completion flags to be used before any other processing is
done, even before processing for <code>compctl</code>s defined for specific
commands. This is especially useful when combined with extended
completion (the <code>-x</code> flag, see <a href="Completion-Using-compctl.html#Extended-Completion">Extended
Completion</a> below). Using this flag you can
define default behavior which will apply to all commands without
exception, or you can alter the standard behavior for all commands.
For example, if your access to the user database is too slow and/or
it contains too many users (so that completion after ‘<code>~</code>’ is too
slow to be usable), you can use</p>
<div class="example">
<pre><code class="language-example">compctl -T -x 's[~] C[0,[^/]#]' -k friends -S/ -tn
</code></pre>
</div>
<p>to complete the strings in the array <code>friends</code> after a ‘<code>~</code>’. The
<code>C[``...``]</code> argument is necessary so that this form of
<code>~</code>-completion is not tried after the directory name is finished.</p>
</li>
<li>
<p><code>-L</code><br />
<em>no argument</em><br />
If no argument is given, <code>compctl</code> lists all defined completions in
an abbreviated form; with a list of <code>options</code>, all completions with
those flags set (not counting extended completion) are listed.</p>
</li>
</ul>
<p>If the <code>+</code> flag is alone and followed immediately by the <code>command</code> list,
the completion behavior for all the commands in the list is reset to the
default. In other words, completion will subsequently use the options
specified by the <code>-D</code> flag.</p>
<p>The form with <code>-M</code> as the first and only option defines global matching
specifications (see <a href="Completion-Widgets.html#Completion-Matching-Control">Completion Matching
Control</a>). The
match specifications given will be used for every completion attempt
(only when using <code>compctl</code>, not with the new completion system) and are
tried in the order in which they are defined until one generates at
least one match. E.g.:</p>
<div class="example">
<pre><code class="language-example">compctl -M '' 'm:{a-zA-Z}={A-Za-z}'
</code></pre>
</div>
<p>This will first try completion without any global match specifications
(the empty string) and, if that generates no matches, will try case
insensitive completion.</p>
<hr />
<p><span id="Option-Flags"></span> <span id="Option-Flags-1"></span></p>
<h2 id="214-option-flags"><a class="header" href="#214-option-flags">21.4 Option Flags</a></h2>
<p>[ <code>-fcFBdeaRGovNAIOPZEnbjrzu/12</code> ]</p>
<p>[ <code>-k</code> <code>array</code> ] [ <code>-g</code> <code>globstring</code> ] [ <code>-s</code> <code>subststring</code> ]</p>
<p>[ <code>-K</code> <code>function</code> ]</p>
<p>[ <code>-Q</code> ] [ <code>-P</code> <code>prefix</code> ] [ <code>-S</code> <code>suffix</code> ]</p>
<p>[ <code>-W</code> <code>file-prefix</code> ] [ <code>-H</code> <code>num pattern</code> ]</p>
<p>[ <code>-q</code> ] [ <code>-X</code> <code>explanation</code> ] [ <code>-Y</code> <code>explanation</code> ]</p>
<p>[ <code>-y</code> <code>func-or-var</code> ] [ <code>-l</code> <code>cmd</code> ] [ <code>-h</code> <code>cmd</code> ] [ <code>-U</code> ]</p>
<p>[ <code>-t</code> <code>continue</code> ] [ <code>-J</code> <code>name</code> ] [ <code>-V</code> <code>name</code> ]</p>
<p>[ <code>-M</code> <code>match-spec</code> ]</p>
<p>The remaining <code>options</code> specify the type of command arguments to look
for during completion. Any combination of these flags may be specified;
the result is a sorted list of all the possibilities. The options are as
follows.</p>
<hr />
<p><span id="Simple-Flags"></span> <span id="Simple-Flags-1"></span></p>
<h3 id="2141-simple-flags"><a class="header" href="#2141-simple-flags">21.4.1 Simple Flags</a></h3>
<p>These produce completion lists made up by the shell itself:</p>
<ul>
<li>
<p><code>-f</code><br />
Filenames and file system paths.</p>
</li>
<li>
<p><code>-/</code><br />
Just file system paths.</p>
</li>
<li>
<p><code>-c</code><br />
Command names, including aliases, shell functions, builtins and
reserved words.</p>
</li>
<li>
<p><code>-F</code><br />
Function names.</p>
</li>
<li>
<p><code>-B</code><br />
Names of builtin commands.</p>
</li>
<li>
<p><code>-m</code><br />
Names of external commands.</p>
</li>
<li>
<p><code>-w</code><br />
Reserved words.</p>
</li>
<li>
<p><code>-a</code><br />
Alias names.</p>
</li>
<li>
<p><code>-R</code><br />
Names of regular (non-global) aliases.</p>
</li>
<li>
<p><code>-G</code><br />
Names of global aliases.</p>
</li>
<li>
<p><code>-d</code><br />
This can be combined with <code>-F</code>, <code>-B</code>, <code>-w</code>, <code>-a</code>, <code>-R</code> and <code>-G</code> to
get names of disabled functions, builtins, reserved words or
aliases.</p>
</li>
<li>
<p><code>-e</code><br />
This option (to show enabled commands) is in effect by default, but
may be combined with <code>-d</code>; <code>-de</code> in combination with <code>-F</code>, <code>-B</code>,
<code>-w</code>, <code>-a</code>, <code>-R</code> and <code>-G</code> will complete names of functions,
builtins, reserved words or aliases whether or not they are
disabled.</p>
</li>
<li>
<p><code>-o</code><br />
Names of shell options (see <a href="Options.html#Options">Options</a>).</p>
</li>
<li>
<p><code>-v</code><br />
Names of any variable defined in the shell.</p>
</li>
<li>
<p><code>-N</code><br />
Names of scalar (non-array) parameters.</p>
</li>
<li>
<p><code>-A</code><br />
Array names.</p>
</li>
<li>
<p><code>-I</code><br />
Names of integer variables.</p>
</li>
<li>
<p><code>-O</code><br />
Names of read-only variables.</p>
</li>
<li>
<p><code>-p</code><br />
Names of parameters used by the shell (including special
parameters).</p>
</li>
<li>
<p><code>-Z</code><br />
Names of shell special parameters.</p>
</li>
<li>
<p><code>-E</code><br />
Names of environment variables.</p>
</li>
<li>
<p><code>-n</code><br />
Named directories.</p>
</li>
<li>
<p><code>-b</code><br />
Key binding names.</p>
</li>
<li>
<p><code>-j</code><br />
Job names: the first word of the job leader’s command line. This is
useful with the <code>kill</code> builtin.</p>
</li>
<li>
<p><code>-r</code><br />
Names of running jobs.</p>
</li>
<li>
<p><code>-z</code><br />
Names of suspended jobs.</p>
</li>
<li>
<p><code>-u</code><br />
User names.</p>
</li>
</ul>
<hr />
<p><span id="Flags-with-Arguments"></span>
<span id="Flags-with-Arguments-1"></span></p>
<h3 id="2142-flags-with-arguments"><a class="header" href="#2142-flags-with-arguments">21.4.2 Flags with Arguments</a></h3>
<p>These have user supplied arguments to determine how the list of
completions is to be made up:</p>
<ul>
<li>
<p><code>-k</code> <code>array</code><br />
Names taken from the elements of <code>$``array</code> (note that the ‘<code>$</code>’
does not appear on the command line). Alternatively, the argument
<code>array</code> itself may be a set of space- or comma-separated values in
parentheses, in which any delimiter may be escaped with a backslash;
in this case the argument should be quoted. For example,</p>
<div class="example">
<pre><code class="language-example">compctl -k &quot;(cputime filesize datasize stacksize
coredumpsize resident descriptors)&quot; limit
</code></pre>
</div>
</li>
<li>
<p><code>-g</code> <code>globstring</code><br />
The <code>globstring</code> is expanded using filename globbing; it should be
quoted to protect it from immediate expansion. The resulting
filenames are taken as the possible completions. Use ‘<code>*(/)</code>’
instead of ‘<code>*/</code>’ for directories. The <code>fignore</code> special parameter
is not applied to the resulting files. More than one pattern may be
given separated by blanks. (Note that brace expansion is <em>not</em> part
of globbing. Use the syntax ‘<code>(either|or)</code>’ to match alternatives.)</p>
</li>
<li>
<p><code>-s</code> <code>subststring</code><br />
The <code>subststring</code> is split into words and these words are than
expanded using all shell expansion mechanisms (see
<a href="Expansion.html#Expansion">Expansion</a>). The resulting words are
taken as possible completions. The <code>fignore</code> special parameter is
not applied to the resulting files. Note that <code>-g</code> is faster for
filenames.</p>
</li>
<li>
<p><code>-K</code> <code>function</code><br />
<span id="index-reply_002c-use-of-2"></span></p>
<p>Call the given function to get the completions. Unless the name
starts with an underscore, the function is passed two arguments: the
prefix and the suffix of the word on which completion is to be
attempted, in other words those characters before the cursor
position, and those from the cursor position onwards. The whole
command line can be accessed with the <code>-c</code> and <code>-l</code> flags of the
<code>read</code> builtin. The function should set the variable <code>reply</code> to an
array containing the completions (one completion per element); note
that <code>reply</code> should not be made local to the function. From such a
function the command line can be accessed with the <code>-c</code> and <code>-l</code>
flags to the <code>read</code> builtin. For example,</p>
<div class="example">
<pre><code class="language-example">function whoson { reply=(`users`); }
compctl -K whoson talk
</code></pre>
</div>
<p>completes only logged-on users after ‘<code>talk</code>’. Note that ‘<code>whoson</code>’
must return an array, so ‘<code>reply=‘users‘</code>’ would be incorrect.</p>
</li>
<li>
<p><code>-H</code> <code>num pattern</code><br />
The possible completions are taken from the last <code>num</code> history
lines. Only words matching <code>pattern</code> are taken. If <code>num</code> is zero or
negative the whole history is searched and if <code>pattern</code> is the empty
string all words are taken (as with ‘<code>*</code>’). A typical use is</p>
<div class="example">
<pre><code class="language-example">compctl -D -f + -H 0 ''
</code></pre>
</div>
<p>which forces completion to look back in the history list for a word
if no filename matches.</p>
</li>
</ul>
<hr />
<p><span id="Control-Flags"></span> <span id="Control-Flags-1"></span></p>
<h3 id="2143-control-flags"><a class="header" href="#2143-control-flags">21.4.3 Control Flags</a></h3>
<p>These do not directly specify types of name to be completed, but
manipulate the options that do:</p>
<ul>
<li>
<p><code>-Q</code><br />
This instructs the shell not to quote any metacharacters in the
possible completions. Normally the results of a completion are
inserted into the command line with any metacharacters quoted so
that they are interpreted as normal characters. This is appropriate
for filenames and ordinary strings. However, for special effects,
such as inserting a backquoted expression from a completion array
(<code>-k</code>) so that the expression will not be evaluated until the
complete line is executed, this option must be used.</p>
</li>
<li>
<p><code>-P</code> <code>prefix</code><br />
The <code>prefix</code> is inserted just before the completed string; any
initial part already typed will be completed and the whole <code>prefix</code>
ignored for completion purposes. For example,</p>
<div class="example">
<pre><code class="language-example">compctl -j -P &quot;%&quot; kill
</code></pre>
</div>
<p>inserts a ‘%’ after the kill command and then completes job names.</p>
</li>
<li>
<p><code>-S</code> <code>suffix</code><br />
When a completion is found the <code>suffix</code> is inserted after the
completed string. In the case of menu completion the suffix is
inserted immediately, but it is still possible to cycle through the
list of completions by repeatedly hitting the same key.</p>
</li>
<li>
<p><code>-W</code> <code>file-prefix</code><br />
With directory <code>file-prefix</code>: for command, file, directory and
globbing completion (options <code>-c</code>, <code>-f</code>, <code>-/</code>, <code>-g</code>), the file
prefix is implicitly added in front of the completion. For example,</p>
<div class="example">
<pre><code class="language-example">compctl -/ -W ~/Mail maildirs
</code></pre>
</div>
<p>completes any subdirectories to any depth beneath the directory
<code>~/Mail</code>, although that prefix does not appear on the command line.
The <code>file-prefix</code> may also be of the form accepted by the <code>-k</code> flag,
i.e. the name of an array or a literal list in parenthesis. In this
case all the directories in the list will be searched for possible
completions.</p>
</li>
<li>
<p><code>-q</code><br />
If used with a suffix as specified by the <code>-S</code> option, this causes
the suffix to be removed if the next character typed is a blank or
does not insert anything or if the suffix consists of only one
character and the next character typed is the same character; this
the same rule used for the <code>AUTO_REMOVE_SLASH</code> option. The option is
most useful for list separators (comma, colon, etc.).</p>
</li>
<li>
<p><code>-l</code> <code>cmd</code><br />
This option restricts the range of command line words that are
considered to be arguments. If combined with one of the extended
completion patterns ‘<code>p[</code>...<code>]</code>’, ‘<code>r[</code>...<code>]</code>’, or ‘<code>R[</code>...<code>]</code>’ (see
<a href="Completion-Using-compctl.html#Extended-Completion">Extended Completion</a> below) the range is
restricted to the range of arguments specified in the brackets.
Completion is then performed as if these had been given as arguments
to the <code>cmd</code> supplied with the option. If the <code>cmd</code> string is empty
the first word in the range is instead taken as the command name,
and command name completion performed on the first word in the
range. For example,</p>
<div class="example">
<pre><code class="language-example">compctl -x 'r[-exec,;]' -l '' -- find
</code></pre>
</div>
<p>completes arguments between ‘<code>-exec</code>’ and the following ‘<code>;</code>’ (or
the end of the command line if there is no such string) as if they
were a separate command line.</p>
</li>
<li>
<p><code>-h</code> <code>cmd</code><br />
Normally zsh completes quoted strings as a whole. With this option,
completion can be done separately on different parts of such
strings. It works like the <code>-l</code> option but makes the completion code
work on the parts of the current word that are separated by spaces.
These parts are completed as if they were arguments to the given
<code>cmd</code>. If <code>cmd</code> is the empty string, the first part is completed as
a command name, as with <code>-l</code>.</p>
</li>
<li>
<p><code>-U</code><br />
Use the whole list of possible completions, whether or not they
actually match the word on the command line. The word typed so far
will be deleted. This is most useful with a function (given by the
<code>-K</code> option) which can examine the word components passed to it (or
via the <code>read</code> builtin’s <code>-c</code> and <code>-l</code> flags) and use its own
criteria to decide what matches. If there is no completion, the
original word is retained. Since the produced possible completions
seldom have interesting common prefixes and suffixes, menu
completion is started immediately if <code>AUTO_MENU</code> is set and this
flag is used.</p>
</li>
<li>
<p><code>-y</code> <code>func-or-var</code><br />
<span id="index-reply_002c-use-of-3"></span></p>
<p>The list provided by <code>func-or-var</code> is displayed instead of the list
of completions whenever a listing is required; the actual
completions to be inserted are not affected. It can be provided in
two ways. Firstly, if <code>func-or-var</code> begins with a <code>$</code> it defines a
variable, or if it begins with a left parenthesis a literal array,
which contains the list. A variable may have been set by a call to a
function using the <code>-K</code> option. Otherwise it contains the name of a
function which will be executed to create the list. The function
will be passed as an argument list all matching completions,
including prefixes and suffixes expanded in full, and should set the
array <code>reply</code> to the result. In both cases, the display list will
only be retrieved after a complete list of matches has been created.</p>
<p>Note that the returned list does not have to correspond, even in
length, to the original set of matches, and may be passed as a
scalar instead of an array. No special formatting of characters is
performed on the output in this case; in particular, newlines are
printed literally and if they appear output in columns is
suppressed.</p>
</li>
<li>
<p><code>-X</code> <code>explanation</code><br />
Print <code>explanation</code> when trying completion on the current set of
options. A ‘<code>%n</code>’ in this string is replaced by the number of
matches that were added for this explanation string. The explanation
only appears if completion was tried and there was no unique match,
or when listing completions. Explanation strings will be listed
together with the matches of the group specified together with the
<code>-X</code> option (using the <code>-J</code> or <code>-V</code> option). If the same explanation
string is given to multiple <code>-X</code> options, the string appears only
once (for each group) and the number of matches shown for the ‘<code>%n</code>’
is the total number of all matches for each of these uses. In any
case, the explanation string will only be shown if there was at
least one match added for the explanation string.</p>
<p>The sequences <code>%B</code>, <code>%b</code>, <code>%S</code>, <code>%s</code>, <code>%U</code>, and <code>%u</code> specify output
attributes (bold, standout, and underline), <code>%F</code>, <code>%f</code>, <code>%K</code>, <code>%k</code>
specify foreground and background colours, and <code>%{``...``%}</code> can be
used to include literal escape sequences as in prompts.</p>
</li>
<li>
<p><code>-Y</code> <code>explanation</code><br />
Identical to <code>-X</code>, except that the <code>explanation</code> first undergoes
expansion following the usual rules for strings in double quotes.
The expansion will be carried out after any functions are called for
the <code>-K</code> or <code>-y</code> options, allowing them to set variables.</p>
</li>
<li>
<p><code>-t</code> <code>continue</code><br />
The <code>continue</code>-string contains a character that specifies which set
of completion flags should be used next. It is useful:</p>
<p>(i) With <code>-T</code>, or when trying a list of pattern completions, when
<code>compctl</code> would usually continue with ordinary processing after
finding matches; this can be suppressed with ‘<code>-tn</code>’.</p>
<p>(ii) With a list of alternatives separated by <code>+</code>, when <code>compctl</code>
would normally stop when one of the alternatives generates matches.
It can be forced to consider the next set of completions by adding
‘<code>-t+</code>’ to the flags of the alternative before the ‘<code>+</code>’.</p>
<p>(iii) In an extended completion list (see below), when <code>compctl</code>
would normally continue until a set of conditions succeeded, then
use only the immediately following flags. With ‘<code>-t-</code>’, <code>compctl</code>
will continue trying extended completions after the next ‘<code>-</code>’; with
‘<code>-tx</code>’ it will attempt completion with the default flags, in other
words those before the ‘<code>-x</code>’.</p>
</li>
<li>
<p><code>-J</code> <code>name</code><br />
This gives the name of the group the matches should be placed in.
Groups are listed and sorted separately; likewise, menu completion
will offer the matches in the groups in the order in which the
groups were defined. If no group name is explicitly given, the
matches are stored in a group named <code>default</code>. The first time a
group name is encountered, a group with that name is created. After
that all matches with the same group name are stored in that group.</p>
<p>This can be useful with non-exclusive alternative completions. For
example, in</p>
<div class="example">
<pre><code class="language-example">compctl -f -J files -t+ + -v -J variables foo
</code></pre>
</div>
<p>both files and variables are possible completions, as the <code>-t+</code>
forces both sets of alternatives before and after the <code>+</code> to be
considered at once. Because of the <code>-J</code> options, however, all files
are listed before all variables.</p>
</li>
<li>
<p><code>-V</code> <code>name</code><br />
Like <code>-J</code>, but matches within the group will not be sorted in
listings nor in menu completion. These unsorted groups are in a
different name space from the sorted ones, so groups defined as <code>-J files</code> and <code>-V files</code> are distinct.</p>
</li>
<li>
<p><code>-1</code><br />
If given together with the <code>-V</code> option, makes only consecutive
duplicates in the group be removed. Note that groups with and
without this flag are in different name spaces.</p>
</li>
<li>
<p><code>-2</code><br />
If given together with the <code>-J</code> or <code>-V</code> option, makes all duplicates
be kept. Again, groups with and without this flag are in different
name spaces.</p>
</li>
<li>
<p><code>-M</code> <code>match-spec</code><br />
This defines additional matching control specifications that should
be used only when testing words for the list of flags this flag
appears in. The format of the <code>match-spec</code> string is described in
<a href="Completion-Widgets.html#Completion-Matching-Control">Completion Matching
Control</a>.</p>
</li>
</ul>
<hr />
<p><span id="Alternative-Completion"></span>
<span id="Alternative-Completion-1"></span></p>
<h2 id="215-alternative-completion"><a class="header" href="#215-alternative-completion">21.5 Alternative Completion</a></h2>
<p><code>compctl</code> [ <code>-CDT</code> ] <code>options</code> <code>+</code> <code>options</code> [ <code>+</code> ... ] [ <code>+</code> ]
<code>command</code> ...</p>
<p>The form with ‘<code>+</code>’ specifies alternative options. Completion is tried
with the options before the first ‘<code>+</code>’. If this produces no matches
completion is tried with the flags after the ‘<code>+</code>’ and so on. If there
are no flags after the last ‘<code>+</code>’ and a match has not been found up to
that point, default completion is tried. If the list of flags contains a
<code>-t</code> with a <code>+</code> character, the next list of flags is used even if the
current list produced matches.</p>
<hr />
<p><span id="Extended-Completion"></span></p>
<p>Additional options are available that restrict completion to some part
of the command line; this is referred to as ‘extended completion’.</p>
<p><span id="Extended-Completion-1"></span></p>
<h2 id="216-extended-completion"><a class="header" href="#216-extended-completion">21.6 Extended Completion</a></h2>
<p><code>compctl </code>[ <code>-CDT</code> ] <code>options</code> <code>-x</code> <code>pattern</code> <code>options</code> <code>-</code> ...
<code>-``-</code></p>
<p><code>        </code>[ <code>command</code> ... ]</p>
<p><code>compctl </code>[ <code>-CDT</code> ] <code>options</code> [ <code>-x</code> <code>pattern</code> <code>options</code> <code>-</code> ...
<code>-``-</code> ]</p>
<p><code>        </code>[ <code>+</code> <code>options</code> [ <code>-x</code> ... <code>-``-</code> ] ... [<code>+</code>] ] [
<code>command</code> ... ]</p>
<p>The form with ‘<code>-x</code>’ specifies extended completion for the commands
given; as shown, it may be combined with alternative completion using
‘<code>+</code>’. Each <code>pattern</code> is examined in turn; when a match is found, the
corresponding <code>options</code>, as described in <a href="Completion-Using-compctl.html#Option-Flags">Option Flags</a>
above, are used to generate possible completions. If no <code>pattern</code>
matches, the <code>options</code> given before the <code>-x</code> are used.</p>
<p>Note that each pattern should be supplied as a single argument and
should be quoted to prevent expansion of metacharacters by the shell.</p>
<p>A <code>pattern</code> is built of sub-patterns separated by commas; it matches if
at least one of these sub-patterns matches (they are ‘or’ed). These
sub-patterns are in turn composed of other sub-patterns separated by
white spaces which match if all of the sub-patterns match (they are
‘and’ed). An element of the sub-patterns is of the form
‘<code>c``[</code>...<code>][</code>...<code>]</code>’, where the pairs of brackets may be repeated as
often as necessary, and matches if any of the sets of brackets match (an
‘or’). The example below makes this clearer.</p>
<p>The elements may be any of the following:</p>
<ul>
<li>
<p><code>s[``string``]</code>...<br />
Matches if the current word on the command line starts with one of
the strings given in brackets. The <code>string</code> is not removed and is
not part of the completion.</p>
</li>
<li>
<p><code>S[``string``]</code>...<br />
Like <code>s[``string``]</code> except that the <code>string</code> is part of the
completion.</p>
</li>
<li>
<p><code>p[``from``,``to``]</code>...<br />
Matches if the number of the current word is between one of the
<code>from</code> and <code>to</code> pairs inclusive. The comma and <code>to</code> are optional;
<code>to</code> defaults to the same value as <code>from</code>. The numbers may be
negative: <code>-``n</code> refers to the <code>n</code>’th last word on the line.</p>
</li>
<li>
<p><code>c[``offset``,``string``]</code>...<br />
Matches if the <code>string</code> matches the word offset by <code>offset</code> from the
current word position. Usually <code>offset</code> will be negative.</p>
</li>
<li>
<p><code>C[``offset``,``pattern``]</code>...<br />
Like <code>c</code> but using pattern matching instead.</p>
</li>
<li>
<p><code>w[``index``,``string``]</code>...<br />
Matches if the word in position <code>index</code> is equal to the
corresponding <code>string</code>. Note that the word count is made after any
alias expansion.</p>
</li>
<li>
<p><code>W[``index``,``pattern``]</code>...<br />
Like <code>w</code> but using pattern matching instead.</p>
</li>
<li>
<p><code>n[``index``,``string``]</code>...<br />
Matches if the current word contains <code>string</code>. Anything up to and
including the <code>index</code>th occurrence of this string will not be
considered part of the completion, but the rest will. <code>index</code> may be
negative to count from the end: in most cases, <code>index</code> will be 1 or
-1. For example,</p>
<div class="example">
<pre><code class="language-example">compctl -s '`users`' -x 'n[1,@]' -k hosts -- talk
</code></pre>
</div>
<p>will usually complete usernames, but if you insert an <code>@</code> after the
name, names from the array <code>hosts</code> (assumed to contain hostnames,
though you must make the array yourself) will be completed. Other
commands such as <code>rcp</code> can be handled similarly.</p>
</li>
<li>
<p><code>N[``index``,``string``]</code>...<br />
Like <code>n</code> except that the string will be taken as a character class.
Anything up to and including the <code>index</code>th occurrence of any of the
characters in <code>string</code> will not be considered part of the
completion.</p>
</li>
<li>
<p><code>m[``min``,``max``]</code>...<br />
Matches if the total number of words lies between <code>min</code> and <code>max</code>
inclusive.</p>
</li>
<li>
<p><code>r[``str1``,``str2``]</code>...<br />
Matches if the cursor is after a word with prefix <code>str1</code>. If there
is also a word with prefix <code>str2</code> on the command line after the one
matched by <code>str1</code> it matches only if the cursor is before this word.
If the comma and <code>str2</code> are omitted, it matches if the cursor is
after a word with prefix <code>str1</code>.</p>
</li>
<li>
<p><code>R[``str1``,``str2``]</code>...<br />
Like <code>r</code> but using pattern matching instead.</p>
</li>
<li>
<p><code>q[``str``]</code>...<br />
Matches the word currently being completed is in single quotes and
the <code>str</code> begins with the letter ‘s’, or if completion is done in
double quotes and <code>str</code> starts with the letter ‘d’, or if completion
is done in backticks and <code>str</code> starts with a ‘b’.</p>
</li>
</ul>
<hr />
<p><span id="Example"></span> <span id="Example-3"></span></p>
<h2 id="217-example"><a class="header" href="#217-example">21.7 Example</a></h2>
<div class="example">
<pre><code class="language-example">compctl -u -x 's[+] c[-1,-f],s[-f+]' \
-g '~/Mail/*(:t)' - 's[-f],c[-1,-f]' -f -- mail
</code></pre>
</div>
<p>This is to be interpreted as follows:</p>
<p>If the current command is <code>mail</code>, then</p>
<blockquote>
<p>if ((the current word begins with <code>+</code> and the previous word is <code>-f</code>)
or (the current word begins with <code>-f+</code>)), then complete the
non-directory part (the ‘<code>:t</code>’ glob modifier) of files in the
directory <code>~/Mail</code>; else</p>
<p>if the current word begins with <code>-f</code> or the previous word was <code>-f</code>,
then complete any file; else</p>
<p>complete user names.</p>
</blockquote>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Zsh-Modules.html#22-zsh-modules">22 Zsh Modules</a>
<ul>
<li><a href="Zsh-Modules.html#221-description">22.1 Description</a></li>
<li><a href="Zsh-Modules.html#222-the-zshattr-module">22.2 The zsh/attr Module</a></li>
<li><a href="Zsh-Modules.html#223-the-zshcap-module">22.3 The zsh/cap Module</a></li>
<li><a href="Zsh-Modules.html#224-the-zshclone-module">22.4 The zsh/clone Module</a></li>
<li><a href="Zsh-Modules.html#225-the-zshcompctl-module">22.5 The zsh/compctl Module</a></li>
<li><a href="Zsh-Modules.html#226-the-zshcomplete-module">22.6 The zsh/complete Module</a></li>
<li><a href="Zsh-Modules.html#227-the-zshcomplist-module">22.7 The zsh/complist Module</a>
<ul>
<li><a href="Zsh-Modules.html#2271-colored-completion-listings">22.7.1 Colored completion listings</a></li>
<li><a href="Zsh-Modules.html#2272-scrolling-in-completion-listings">22.7.2 Scrolling in completion listings</a></li>
<li><a href="Zsh-Modules.html#2273-menu-selection">22.7.3 Menu selection</a></li>
</ul>
</li>
<li><a href="Zsh-Modules.html#228-the-zshcomputil-module">22.8 The zsh/computil Module</a></li>
<li><a href="Zsh-Modules.html#229-the-zshcurses-module">22.9 The zsh/curses Module</a>
<ul>
<li><a href="Zsh-Modules.html#2291-builtin">22.9.1 Builtin</a></li>
<li><a href="Zsh-Modules.html#2292-parameters">22.9.2 Parameters</a></li>
</ul>
</li>
<li><a href="Zsh-Modules.html#2210-the-zshdatetime-module">22.10 The zsh/datetime Module</a></li>
<li><a href="Zsh-Modules.html#2211-the-zshdbgdbm-module">22.11 The zsh/db/gdbm Module</a></li>
<li><a href="Zsh-Modules.html#2212-the-zshdeltochar-module">22.12 The zsh/deltochar Module</a></li>
<li><a href="Zsh-Modules.html#2213-the-zshexample-module">22.13 The zsh/example Module</a></li>
<li><a href="Zsh-Modules.html#2214-the-zshfiles-module">22.14 The zsh/files Module</a></li>
<li><a href="Zsh-Modules.html#2215-the-zshlanginfo-module">22.15 The zsh/langinfo Module</a></li>
<li><a href="Zsh-Modules.html#2216-the-zshmapfile-module">22.16 The zsh/mapfile Module</a>
<ul>
<li><a href="Zsh-Modules.html#22161-limitations">22.16.1 Limitations</a></li>
</ul>
</li>
<li><a href="Zsh-Modules.html#2217-the-zshmathfunc-module">22.17 The zsh/mathfunc Module</a></li>
<li><a href="Zsh-Modules.html#2218-the-zshnearcolor-module">22.18 The zsh/nearcolor Module</a></li>
<li><a href="Zsh-Modules.html#2219-the-zshnewuser-module">22.19 The zsh/newuser Module</a></li>
<li><a href="Zsh-Modules.html#2220-the-zshparameter-module">22.20 The zsh/parameter Module</a></li>
<li><a href="Zsh-Modules.html#2221-the-zshpcre-module">22.21 The zsh/pcre Module</a></li>
<li><a href="Zsh-Modules.html#2222-the-zshparamprivate-module">22.22 The zsh/param/private Module</a></li>
<li><a href="Zsh-Modules.html#2223-the-zshregex-module">22.23 The zsh/regex Module</a></li>
<li><a href="Zsh-Modules.html#2224-the-zshsched-module">22.24 The zsh/sched Module</a></li>
<li><a href="Zsh-Modules.html#2225-the-zshnetsocket-module">22.25 The zsh/net/socket Module</a>
<ul>
<li><a href="Zsh-Modules.html#22251-outbound-connections">22.25.1 Outbound Connections</a></li>
<li><a href="Zsh-Modules.html#22252-inbound-connections">22.25.2 Inbound Connections</a></li>
</ul>
</li>
<li><a href="Zsh-Modules.html#2226-the-zshstat-module">22.26 The zsh/stat Module</a></li>
<li><a href="Zsh-Modules.html#2227-the-zshsystem-module">22.27 The zsh/system Module</a>
<ul>
<li><a href="Zsh-Modules.html#22271-builtins">22.27.1 Builtins</a></li>
<li><a href="Zsh-Modules.html#22272-math-functions">22.27.2 Math Functions</a></li>
<li><a href="Zsh-Modules.html#22273-parameters">22.27.3 Parameters</a></li>
</ul>
</li>
<li><a href="Zsh-Modules.html#2228-the-zshnettcp-module">22.28 The zsh/net/tcp Module</a>
<ul>
<li><a href="Zsh-Modules.html#22281-outbound-connections">22.28.1 Outbound Connections</a></li>
<li><a href="Zsh-Modules.html#22282-inbound-connections">22.28.2 Inbound Connections</a></li>
<li><a href="Zsh-Modules.html#22283-closing-connections">22.28.3 Closing Connections</a></li>
<li><a href="Zsh-Modules.html#22284-example">22.28.4 Example</a></li>
</ul>
</li>
<li><a href="Zsh-Modules.html#2229-the-zshtermcap-module">22.29 The zsh/termcap Module</a></li>
<li><a href="Zsh-Modules.html#2230-the-zshterminfo-module">22.30 The zsh/terminfo Module</a></li>
<li><a href="Zsh-Modules.html#2231-the-zshzftp-module">22.31 The zsh/zftp Module</a>
<ul>
<li><a href="Zsh-Modules.html#22311-subcommands">22.31.1 Subcommands</a></li>
<li><a href="Zsh-Modules.html#22312-parameters">22.31.2 Parameters</a></li>
<li><a href="Zsh-Modules.html#22313-functions">22.31.3 Functions</a></li>
<li><a href="Zsh-Modules.html#22314-problems">22.31.4 Problems</a></li>
</ul>
</li>
<li><a href="Zsh-Modules.html#2232-the-zshzle-module">22.32 The zsh/zle Module</a></li>
<li><a href="Zsh-Modules.html#2233-the-zshzleparameter-module">22.33 The zsh/zleparameter Module</a></li>
<li><a href="Zsh-Modules.html#2234-the-zshzprof-module">22.34 The zsh/zprof Module</a></li>
<li><a href="Zsh-Modules.html#2235-the-zshzpty-module">22.35 The zsh/zpty Module</a></li>
<li><a href="Zsh-Modules.html#2236-the-zshzselect-module">22.36 The zsh/zselect Module</a></li>
<li><a href="Zsh-Modules.html#2237-the-zshzutil-module">22.37 The zsh/zutil Module</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Zsh-Modules"></span> <span id="Zsh-Modules-1"></span></p>
<h1 id="22-zsh-modules"><a class="header" href="#22-zsh-modules">22 Zsh Modules</a></h1>
<p><span id="index-modules"></span></p>
<hr />
<p><span id="Description-6"></span></p>
<h2 id="221-description"><a class="header" href="#221-description">22.1 Description</a></h2>
<p>Some optional parts of zsh are in modules, separate from the core of the
shell. Each of these modules may be linked in to the shell at build
time, or can be dynamically linked while the shell is running if the
installation supports this feature. Modules are linked at runtime with
the <code>zmodload</code> command, see <a href="Shell-Builtin-Commands.html#Shell-Builtin-Commands">Shell Builtin
Commands</a>.</p>
<p>The modules that are bundled with the zsh distribution are:</p>
<ul>
<li>
<p><code>zsh/attr</code><br />
Builtins for manipulating extended attributes (xattr).</p>
</li>
<li>
<p><code>zsh/cap</code><br />
Builtins for manipulating POSIX.1e (POSIX.6) capability (privilege)
sets.</p>
</li>
<li>
<p><code>zsh/clone</code><br />
A builtin that can clone a running shell onto another terminal.</p>
</li>
<li>
<p><code>zsh/compctl</code><br />
The <code>compctl</code> builtin for controlling completion.</p>
</li>
<li>
<p><code>zsh/complete</code><br />
The basic completion code.</p>
</li>
<li>
<p><code>zsh/complist</code><br />
Completion listing extensions.</p>
</li>
<li>
<p><code>zsh/computil</code><br />
A module with utility builtins needed for the shell function based
completion system.</p>
</li>
<li>
<p><code>zsh/curses</code><br />
curses windowing commands</p>
</li>
<li>
<p><code>zsh/datetime</code><br />
Some date/time commands and parameters.</p>
</li>
<li>
<p><code>zsh/db/gdbm</code><br />
Builtins for managing associative array parameters tied to GDBM
databases.</p>
</li>
<li>
<p><code>zsh/deltochar</code><br />
A ZLE function duplicating EMACS’ <code>zap-to-char</code>.</p>
</li>
<li>
<p><code>zsh/example</code><br />
An example of how to write a module.</p>
</li>
<li>
<p><code>zsh/files</code><br />
Some basic file manipulation commands as builtins.</p>
</li>
<li>
<p><code>zsh/langinfo</code><br />
Interface to locale information.</p>
</li>
<li>
<p><code>zsh/mapfile</code><br />
Access to external files via a special associative array.</p>
</li>
<li>
<p><code>zsh/mathfunc</code><br />
Standard scientific functions for use in mathematical evaluations.</p>
</li>
<li>
<p><code>zsh/nearcolor</code><br />
Map colours to the nearest colour in the available palette.</p>
</li>
<li>
<p><code>zsh/newuser</code><br />
Arrange for files for new users to be installed.</p>
</li>
<li>
<p><code>zsh/parameter</code><br />
<code>zsh/pcre</code><br />
Interface to the PCRE library.</p>
</li>
<li>
<p><code>zsh/param/private</code><br />
Builtins for managing private-scoped parameters in function context.</p>
</li>
<li>
<p><code>zsh/regex</code><br />
Interface to the POSIX regex library.</p>
</li>
<li>
<p><code>zsh/sched</code><br />
A builtin that provides a timed execution facility within the shell.</p>
</li>
<li>
<p><code>zsh/net/socket</code><br />
Manipulation of Unix domain sockets</p>
</li>
<li>
<p><code>zsh/stat</code><br />
A builtin command interface to the <code>stat</code> system call.</p>
</li>
<li>
<p><code>zsh/system</code><br />
A builtin interface to various low-level system features.</p>
</li>
<li>
<p><code>zsh/net/tcp</code><br />
Manipulation of TCP sockets</p>
</li>
<li>
<p><code>zsh/termcap</code><br />
Interface to the termcap database.</p>
</li>
<li>
<p><code>zsh/terminfo</code><br />
Interface to the terminfo database.</p>
</li>
<li>
<p><code>zsh/zftp</code><br />
A builtin FTP client.</p>
</li>
<li>
<p><code>zsh/zle</code><br />
The Zsh Line Editor, including the <code>bindkey</code> and <code>vared</code> builtins.</p>
</li>
<li>
<p><code>zsh/zleparameter</code><br />
Access to internals of the Zsh Line Editor via parameters.</p>
</li>
<li>
<p><code>zsh/zprof</code><br />
A module allowing profiling for shell functions.</p>
</li>
<li>
<p><code>zsh/zpty</code><br />
A builtin for starting a command in a pseudo-terminal.</p>
</li>
<li>
<p><code>zsh/zselect</code><br />
Block and return when file descriptors are ready.</p>
</li>
<li>
<p><code>zsh/zutil</code><br />
Some utility builtins, e.g. the one for supporting configuration via
styles.</p>
</li>
</ul>
<hr />
<p><span id="The-zsh_002fattr-Module"></span>
<span id="The-zsh_002fattr-Module-1"></span></p>
<h2 id="222-the-zshattr-module"><a class="header" href="#222-the-zshattr-module">22.2 The zsh/attr Module</a></h2>
<p>The <code>zsh/attr</code> module is used for manipulating extended attributes. The
<code>-h</code> option causes all commands to operate on symbolic links instead of
their targets. The builtins in this module are:</p>
<p><span id="index-zgetattr"></span>
<span id="index-extended-attributes_002c-xattr_002c-getting-from-files"></span></p>
<p><code>zgetattr</code> [ <code>-h</code> ] <code>filename</code> <code>attribute</code> [ <code>parameter</code> ]</p>
<p>Get the extended attribute <code>attribute</code> from the specified <code>filename</code>. If
the optional argument <code>parameter</code> is given, the attribute is set on that
parameter instead of being printed to stdout.</p>
<p><span id="index-zsetattr"></span>
<span id="index-extended-attributes_002c-xattr_002c-setting-on-files"></span></p>
<p><code>zsetattr</code> [ <code>-h</code> ] <code>filename</code> <code>attribute</code> <code>value</code></p>
<p>Set the extended attribute <code>attribute</code> on the specified <code>filename</code> to
<code>value</code>.</p>
<p><span id="index-zdelattr"></span>
<span id="index-extended-attributes_002c-xattr_002c-removing_002c-deleting"></span></p>
<p><code>zdelattr</code> [ <code>-h</code> ] <code>filename</code> <code>attribute</code></p>
<p>Remove the extended attribute <code>attribute</code> from the specified <code>filename</code>.</p>
<p><span id="index-zlistattr"></span>
<span id="index-extended-attributes_002c-xattr_002c-listing"></span></p>
<p><code>zlistattr</code> [ <code>-h</code> ] <code>filename</code> [ <code>parameter</code> ]</p>
<p>List the extended attributes currently set on the specified <code>filename</code>.
If the optional argument <code>parameter</code> is given, the list of attributes is
set on that parameter instead of being printed to stdout.</p>
<p><code>zgetattr</code> and <code>zlistattr</code> allocate memory dynamically. If the attribute
or list of attributes grows between the allocation and the call to get
them, they return 2. On all other errors, 1 is returned. This allows the
calling function to check for this case and retry.</p>
<hr />
<p><span id="The-zsh_002fcap-Module"></span>
<span id="The-zsh_002fcap-Module-1"></span></p>
<h2 id="223-the-zshcap-module"><a class="header" href="#223-the-zshcap-module">22.3 The zsh/cap Module</a></h2>
<p>The <code>zsh/cap</code> module is used for manipulating POSIX.1e (POSIX.6)
capability sets. If the operating system does not support this
interface, the builtins defined by this module will do nothing. The
builtins in this module are:</p>
<p><span id="index-cap"></span>
<span id="index-capabilities_002c-setting"></span></p>
<p><code>cap</code> [ <code>capabilities</code> ]</p>
<p>Change the shell’s process capability sets to the specified
<code>capabilities</code>, otherwise display the shell’s current capabilities.</p>
<p><span id="index-getcap"></span>
<span id="index-capabilities_002c-getting-from-files"></span></p>
<p><code>getcap</code> <code>filename</code> ...</p>
<p>This is a built-in implementation of the POSIX standard utility. It
displays the capability sets on each specified <code>filename</code>.</p>
<p><span id="index-setcap"></span>
<span id="index-capabilities_002c-setting-on-files"></span></p>
<p><code>setcap</code> <code>capabilities</code> <code>filename</code> ...</p>
<p>This is a built-in implementation of the POSIX standard utility. It sets
the capability sets on each specified <code>filename</code> to the specified
<code>capabilities</code>.</p>
<hr />
<p><span id="The-zsh_002fclone-Module"></span>
<span id="The-zsh_002fclone-Module-1"></span></p>
<h2 id="224-the-zshclone-module"><a class="header" href="#224-the-zshclone-module">22.4 The zsh/clone Module</a></h2>
<p>The <code>zsh/clone</code> module makes available one builtin command:</p>
<p><span id="index-clone"></span>
<span id="index-shell_002c-cloning"></span>
<span id="index-cloning-the-shell"></span>
<span id="index-terminal"></span></p>
<p><code>clone</code> <code>tty</code></p>
<p>Creates a forked instance of the current shell, attached to the
specified <code>tty</code>. In the new shell, the <code>PID</code>, <code>PPID</code> and <code>TTY</code> special
parameters are changed appropriately. <code>$!</code> is set to zero in the new
shell, and to the new shell’s PID in the original shell.</p>
<p>The return status of the builtin is zero in both shells if successful,
and non-zero on error.</p>
<p>The target of <code>clone</code> should be an unused terminal, such as an unused
virtual console or a virtual terminal created by</p>
<div class="example">
<pre><code class="language-example">xterm -e sh -c 'trap : INT QUIT TSTP; tty;
while :; do sleep 100000000; done'
</code></pre>
</div>
<p>Some words of explanation are warranted about this long xterm command
line: when doing clone on a pseudo-terminal, some other session
(&quot;session&quot; meant as a unix session group, or SID) is already owning the
terminal. Hence the cloned zsh cannot acquire the pseudo-terminal as a
controlling tty. That means two things:</p>
<ul>
<li>the job control signals will go to the sh-started-by-xterm process
group (that’s why we disable INT QUIT and TSTP with trap; otherwise
the while loop could get suspended or killed)</li>
<li>the cloned shell will have job control disabled, and the job control
keys (control-C, control-\ and control-Z) will not work.</li>
</ul>
<p>This does not apply when cloning to an <em>unused</em> vc.</p>
<p>Cloning to a used (and unprepared) terminal will result in two processes
reading simultaneously from the same terminal, with input bytes going
randomly to either process.</p>
<p><code>clone</code> is mostly useful as a shell built-in replacement for openvt.</p>
<hr />
<p><span id="The-zsh_002fcompctl-Module"></span>
<span id="The-zsh_002fcompctl-Module-1"></span></p>
<h2 id="225-the-zshcompctl-module"><a class="header" href="#225-the-zshcompctl-module">22.5 The zsh/compctl Module</a></h2>
<p>The <code>zsh/compctl</code> module makes available two builtin commands.
<code>compctl</code>, is the old, deprecated way to control completions for ZLE.
See <a href="Completion-Using-compctl.html#Completion-Using-compctl">Completion Using
compctl</a>. The
other builtin command, <code>compcall</code> can be used in user-defined completion
widgets, see <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a>.</p>
<hr />
<p><span id="The-zsh_002fcomplete-Module"></span>
<span id="The-zsh_002fcomplete-Module-1"></span></p>
<h2 id="226-the-zshcomplete-module"><a class="header" href="#226-the-zshcomplete-module">22.6 The zsh/complete Module</a></h2>
<p>The <code>zsh/complete</code> module makes available several builtin commands which
can be used in user-defined completion widgets, see <a href="Completion-Widgets.html#Completion-Widgets">Completion
Widgets</a>.</p>
<hr />
<p><span id="The-zsh_002fcomplist-Module"></span>
<span id="The-zsh_002fcomplist-Module-1"></span></p>
<h2 id="227-the-zshcomplist-module"><a class="header" href="#227-the-zshcomplist-module">22.7 The zsh/complist Module</a></h2>
<p><span id="index-completion_002c-listing-1"></span>
<span id="index-completion_002c-coloured-listings"></span>
<span id="index-completion_002c-scroll-listings"></span></p>
<p>The <code>zsh/complist</code> module offers three extensions to completion
listings: the ability to highlight matches in such a list, the ability
to scroll through long lists and a different style of menu completion.</p>
<hr />
<p><span id="Colored-completion-listings"></span></p>
<h3 id="2271-colored-completion-listings"><a class="header" href="#2271-colored-completion-listings">22.7.1 Colored completion listings</a></h3>
<p>Whenever one of the parameters <code>ZLS_COLORS</code> or <code>ZLS_COLOURS</code> is set and
the <code>zsh/complist</code> module is loaded or linked into the shell, completion
lists will be colored. Note, however, that <code>complist</code> will not
automatically be loaded if it is not linked in: on systems with dynamic
loading, ‘<code>zmodload zsh/complist</code>’ is required.</p>
<p><span id="index-ZLS_005fCOLORS"></span>
<span id="index-ZLS_005fCOLOURS"></span></p>
<p>The parameters <code>ZLS_COLORS</code> and <code>ZLS_COLOURS</code> describe how matches are
highlighted. To turn on highlighting an empty value suffices, in which
case all the default values given below will be used. The format of the
value of these parameters is the same as used by the GNU version of the
<code>ls</code> command: a colon-separated list of specifications of the form
‘<code>name``=``value</code>’. The <code>name</code> may be one of the following strings,
most of which specify file types for which the <code>value</code> will be used. The
strings and their default values are:</p>
<ul>
<li>
<p><code>no 0</code><br />
for normal text (i.e. when displaying something other than a matched
file)</p>
</li>
<li>
<p><code>fi 0</code><br />
for regular files</p>
</li>
<li>
<p><code>di 32</code><br />
for directories</p>
</li>
<li>
<p><code>ln 36</code><br />
for symbolic links. If this has the special value <code>target</code>, symbolic
links are dereferenced and the target file used to determine the
display format.</p>
</li>
<li>
<p><code>pi 31</code><br />
for named pipes (FIFOs)</p>
</li>
<li>
<p><code>so 33</code><br />
for sockets</p>
</li>
<li>
<p><code>bd 44;37</code><br />
for block devices</p>
</li>
<li>
<p><code>cd 44;37</code><br />
for character devices</p>
</li>
<li>
<p><code>or</code> <code>none</code><br />
for a symlink to nonexistent file (default is the value defined for
<code>ln</code>)</p>
</li>
<li>
<p><code>mi</code> <code>none</code><br />
for a non-existent file (default is the value defined for <code>fi</code>);
this code is currently not used</p>
</li>
<li>
<p><code>su 37;41</code><br />
for files with setuid bit set</p>
</li>
<li>
<p><code>sg 30;43</code><br />
for files with setgid bit set</p>
</li>
<li>
<p><code>tw 30;42</code><br />
<code>ow 34;43</code><br />
<code>sa</code> <code>none</code><br />
for files with an associated suffix alias; this is only tested after
specific suffixes, as described below</p>
</li>
<li>
<p><code>st 37;44</code><br />
<code>ex 35</code><br />
<code>lc \e[</code><br />
for the left code (see below)</p>
</li>
<li>
<p><code>rc m</code><br />
for the right code</p>
</li>
<li>
<p><code>tc 0</code><br />
for the character indicating the file type printed after filenames
if the <code>LIST_TYPES</code> option is set</p>
</li>
<li>
<p><code>sp 0</code><br />
for the spaces printed after matches to align the next column</p>
</li>
<li>
<p><code>ec</code> <code>none</code><br />
for the end code</p>
</li>
</ul>
<p>Apart from these strings, the <code>name</code> may also be an asterisk (‘<code>*</code>’)
followed by any string. The <code>value</code> given for such a string will be used
for all files whose name ends with the string. The <code>name</code> may also be an
equals sign (‘<code>=</code>’) followed by a pattern; the <code>EXTENDED_GLOB</code> option
will be turned on for evaluation of the pattern. The <code>value</code> given for
this pattern will be used for all matches (not just filenames) whose
display string are matched by the pattern. Definitions for the form with
the leading equal sign take precedence over the values defined for file
types, which in turn take precedence over the form with the leading
asterisk (file extensions).</p>
<p>The leading-equals form also allows different parts of the displayed
strings to be colored differently. For this, the pattern has to use the
‘<code>(#b)</code>’ globbing flag and pairs of parentheses surrounding the parts
of the strings that are to be colored differently. In this case the
<code>value</code> may consist of more than one color code separated by equal
signs. The first code will be used for all parts for which no explicit
code is specified and the following codes will be used for the parts
matched by the sub-patterns in parentheses. For example, the
specification ‘<code>=(#b)(?)*(?)=0=3=7</code>’ will be used for all matches which
are at least two characters long and will use the code ‘<code>3</code>’ for the
first character, ‘<code>7</code>’ for the last character and ‘<code>0</code>’ for the rest.</p>
<p>All three forms of <code>name</code> may be preceded by a pattern in parentheses.
If this is given, the <code>value</code> will be used only for matches in groups
whose names are matched by the pattern given in the parentheses. For
example, ‘<code>(g*)m*=43</code>’ highlights all matches beginning with ‘<code>m</code>’ in
groups whose names begin with ‘<code>g</code>’ using the color code ‘<code>43</code>’. In case
of the ‘<code>lc</code>’, ‘<code>rc</code>’, and ‘<code>ec</code>’ codes, the group pattern is ignored.</p>
<p>Note also that all patterns are tried in the order in which they appear
in the parameter value until the first one matches which is then used.
Patterns may be matched against completions, descriptions (possibly with
spaces appended for padding), or lines consisting of a completion
followed by a description. For consistent coloring it may be necessary
to use more than one pattern or a pattern with backreferences.</p>
<p>When printing a match, the code prints the value of <code>lc</code>, the value for
the file-type or the last matching specification with a ‘<code>*</code>’, the value
of <code>rc</code>, the string to display for the match itself, and then the value
of <code>ec</code> if that is defined or the values of <code>lc</code>, <code>no</code>, and <code>rc</code> if <code>ec</code>
is not defined.</p>
<p>The default values are ISO 6429 (ANSI) compliant and can be used on
vt100 compatible terminals such as <code>xterm</code>s. On monochrome terminals the
default values will have no visible effect. The <code>colors</code> function from
the contribution can be used to get associative arrays containing the
codes for ANSI terminals (see <a href="User-Contributions.html#Other-Functions">Other
Functions</a>). For example, after
loading <code>colors</code>, one could use ‘<code>$color[red]</code>’ to get the code for
foreground color red and ‘<code>$color[bg-green]</code>’ for the code for
background color green.</p>
<p>If the completion system invoked by compinit is used, these parameters
should not be set directly because the system controls them itself.
Instead, the <code>list-colors</code> style should be used (see <a href="Completion-System.html#Completion-System-Configuration">Completion System
Configuration</a>).</p>
<hr />
<p><span id="Scrolling-in-completion-listings"></span></p>
<h3 id="2272-scrolling-in-completion-listings"><a class="header" href="#2272-scrolling-in-completion-listings">22.7.2 Scrolling in completion listings</a></h3>
<p>To enable scrolling through a completion list, the <code>LISTPROMPT</code>
parameter must be set. Its value will be used as the prompt; if it is
the empty string, a default prompt will be used. The value may contain
escapes of the form ‘<code>%x</code>’. It supports the escapes ‘<code>%B</code>’, ‘<code>%b</code>’,
‘<code>%S</code>’, ‘<code>%s</code>’, ‘<code>%U</code>’, ‘<code>%u</code>’, ‘<code>%F</code>’, ‘<code>%f</code>’, ‘<code>%K</code>’, ‘<code>%k</code>’ and
‘<code>%{``...``%}</code>’ used also in shell prompts as well as three pairs of
additional sequences: a ‘<code>%l</code>’ or ‘<code>%L</code>’ is replaced by the number of
the last line shown and the total number of lines in the form
‘<code>number``/``total</code>’; a ‘<code>%m</code>’ or ‘<code>%M</code>’ is replaced with the number
of the last match shown and the total number of matches; and ‘<code>%p</code>’ or
‘<code>%P</code>’ is replaced with ‘<code>Top</code>’, ‘<code>Bottom</code>’ or the position of the
first line shown in percent of the total number of lines, respectively.
In each of these cases the form with the uppercase letter will be
replaced with a string of fixed width, padded to the right with spaces,
while the lowercase form will not be padded.</p>
<p>If the parameter <code>LISTPROMPT</code> is set, the completion code will not ask
if the list should be shown. Instead it immediately starts displaying
the list, stopping after the first screenful, showing the prompt at the
bottom, waiting for a keypress after temporarily switching to the
<code>listscroll</code> keymap. Some of the zle functions have a special meaning
while scrolling lists:</p>
<ul>
<li>
<p><code>send-break</code><br />
stops listing discarding the key pressed</p>
</li>
<li>
<p><code>accept-line</code>, <code>down-history</code>, <code>down-line-or-history</code><br />
<code>down-line-or-search</code>, <code>vi-down-line-or-history</code><br />
scrolls forward one line</p>
</li>
<li>
<p><code>complete-word</code>, <code>menu-complete</code>, <code>expand-or-complete</code><br />
<code>expand-or-complete-prefix</code>, <code>menu-complete-or-expand</code><br />
scrolls forward one screenful</p>
</li>
<li>
<p><code>accept-search</code><br />
stop listing but take no other action</p>
</li>
</ul>
<p>Every other character stops listing and immediately processes the key as
usual. Any key that is not bound in the <code>listscroll</code> keymap or that is
bound to <code>undefined-key</code> is looked up in the keymap currently selected.</p>
<p>As for the <code>ZLS_COLORS</code> and <code>ZLS_COLOURS</code> parameters, <code>LISTPROMPT</code>
should not be set directly when using the shell function based
completion system. Instead, the <code>list-prompt</code> style should be used.</p>
<hr />
<p><span id="Menu-selection"></span></p>
<h3 id="2273-menu-selection"><a class="header" href="#2273-menu-selection">22.7.3 Menu selection</a></h3>
<p><span id="index-completion_002c-selecting-by-cursor"></span>
<span id="index-MENUSELECT"></span>
<span id="index-menu_002dselect"></span></p>
<p>The <code>zsh/complist</code> module also offers an alternative style of selecting
matches from a list, called menu selection, which can be used if the
shell is set up to return to the last prompt after showing a completion
list (see the <code>ALWAYS_LAST_PROMPT</code> option in
<a href="Options.html#Options">Options</a>).</p>
<p>Menu selection can be invoked directly by the widget <code>menu-select</code>
defined by this module. This is a standard ZLE widget that can be bound
to a key in the usual way as described in <a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh Line
Editor</a>.</p>
<p>Alternatively, the parameter <code>MENUSELECT</code> can be set to an integer,
which gives the minimum number of matches that must be present before
menu selection is automatically turned on. This second method requires
that menu completion be started, either directly from a widget such as
<code>menu-complete</code>, or due to one of the options <code>MENU_COMPLETE</code> or
<code>AUTO_MENU</code> being set. If <code>MENUSELECT</code> is set, but is 0, 1 or empty,
menu selection will always be started during an ambiguous menu
completion.</p>
<p>When using the completion system based on shell functions, the
<code>MENUSELECT</code> parameter should not be used (like the <code>ZLS_COLORS</code> and
<code>ZLS_COLOURS</code> parameters described above). Instead, the <code>menu</code> style
should be used with the <code>select=``...</code> keyword.</p>
<p>After menu selection is started, the matches will be listed. If there
are more matches than fit on the screen, only the first screenful is
shown. The matches to insert into the command line can be selected from
this list. In the list one match is highlighted using the value for <code>ma</code>
from the <code>ZLS_COLORS</code> or <code>ZLS_COLOURS</code> parameter. The default value for
this is ‘<code>7</code>’ which forces the selected match to be highlighted using
standout mode on a vt100-compatible terminal. If neither <code>ZLS_COLORS</code>
nor <code>ZLS_COLOURS</code> is set, the same terminal control sequence as for the
‘<code>%S</code>’ escape in prompts is used.</p>
<p>If there are more matches than fit on the screen and the parameter
<code>MENUPROMPT</code> is set, its value will be shown below the matches. It
supports the same escape sequences as <code>LISTPROMPT</code>, but the number of
the match or line shown will be that of the one where the mark is
placed. If its value is the empty string, a default prompt will be used.</p>
<p>The <code>MENUSCROLL</code> parameter can be used to specify how the list is
scrolled. If the parameter is unset, this is done line by line, if it is
set to ‘<code>0</code>’ (zero), the list will scroll half the number of lines of
the screen. If the value is positive, it gives the number of lines to
scroll and if it is negative, the list will be scrolled the number of
lines of the screen minus the (absolute) value.</p>
<p>As for the <code>ZLS_COLORS</code>, <code>ZLS_COLOURS</code> and <code>LISTPROMPT</code> parameters,
neither <code>MENUPROMPT</code> nor <code>MENUSCROLL</code> should be set directly when using
the shell function based completion system. Instead, the <code>select-prompt</code>
and <code>select-scroll</code> styles should be used.</p>
<p>The completion code sometimes decides not to show all of the matches in
the list. These hidden matches are either matches for which the
completion function which added them explicitly requested that they not
appear in the list (using the <code>-n</code> option of the <code>compadd</code> builtin
command) or they are matches which duplicate a string already in the
list (because they differ only in things like prefixes or suffixes that
are not displayed). In the list used for menu selection, however, even
these matches are shown so that it is possible to select them. To
highlight such matches the <code>hi</code> and <code>du</code> capabilities in the
<code>ZLS_COLORS</code> and <code>ZLS_COLOURS</code> parameters are supported for hidden
matches of the first and second kind, respectively.</p>
<p>Selecting matches is done by moving the mark around using the zle
movement functions. When not all matches can be shown on the screen at
the same time, the list will scroll up and down when crossing the top or
bottom line. The following zle functions have special meaning during
menu selection. Note that the following always perform the same task
within the menu selection map and cannot be replaced by user defined
widgets, nor can the set of functions be extended:</p>
<ul>
<li>
<p><code>accept-line</code>, <code>accept-search</code><br />
accept the current match and leave menu selection (but do not cause
the command line to be accepted)</p>
</li>
<li>
<p><code>send-break</code><br />
leaves menu selection and restores the previous contents of the
command line</p>
</li>
<li>
<p><code>redisplay</code>, <code>clear-screen</code><br />
execute their normal function without leaving menu selection</p>
</li>
<li>
<p><code>accept-and-hold</code>, <code>accept-and-menu-complete</code><br />
accept the currently inserted match and continue selection allowing
to select the next match to insert into the line</p>
</li>
<li>
<p><code>accept-and-infer-next-history</code><br />
accepts the current match and then tries completion with menu
selection again; in the case of files this allows one to select a
directory and immediately attempt to complete files in it; if there
are no matches, a message is shown and one can use <code>undo</code> to go back
to completion on the previous level, every other key leaves menu
selection (including the other zle functions which are otherwise
special during menu selection)</p>
</li>
<li>
<p><code>undo</code><br />
removes matches inserted during the menu selection by one of the
three functions before</p>
</li>
<li>
<p><code>down-history</code>, <code>down-line-or-history</code><br />
<code>vi-down-line-or-history</code>, <code>down-line-or-search</code><br />
moves the mark one line down</p>
</li>
<li>
<p><code>up-history</code>, <code>up-line-or-history</code><br />
<code>vi-up-line-or-history</code>, <code>up-line-or-search</code><br />
moves the mark one line up</p>
</li>
<li>
<p><code>forward-char</code>, <code>vi-forward-char</code><br />
moves the mark one column right</p>
</li>
<li>
<p><code>backward-char</code>, <code>vi-backward-char</code><br />
moves the mark one column left</p>
</li>
<li>
<p><code>forward-word</code>, <code>vi-forward-word</code><br />
<code>vi-forward-word-end</code>, <code>emacs-forward-word</code><br />
moves the mark one screenful down</p>
</li>
<li>
<p><code>backward-word</code>, <code>vi-backward-word</code>, <code>emacs-backward-word</code><br />
moves the mark one screenful up</p>
</li>
<li>
<p><code>vi-forward-blank-word</code>, <code>vi-forward-blank-word-end</code><br />
moves the mark to the first line of the next group of matches</p>
</li>
<li>
<p><code>vi-backward-blank-word</code><br />
moves the mark to the last line of the previous group of matches</p>
</li>
<li>
<p><code>beginning-of-history</code><br />
moves the mark to the first line</p>
</li>
<li>
<p><code>end-of-history</code><br />
moves the mark to the last line</p>
</li>
<li>
<p><code>beginning-of-buffer-or-history</code>, <code>beginning-of-line</code><br />
<code>beginning-of-line-hist</code>, <code>vi-beginning-of-line</code><br />
moves the mark to the leftmost column</p>
</li>
<li>
<p><code>end-of-buffer-or-history</code>, <code>end-of-line</code><br />
<code>end-of-line-hist</code>, <code>vi-end-of-line</code><br />
moves the mark to the rightmost column</p>
</li>
<li>
<p><code>complete-word</code>, <code>menu-complete</code>, <code>expand-or-complete</code><br />
<code>expand-or-complete-prefix</code>, <code>menu-expand-or-complete</code><br />
moves the mark to the next match</p>
</li>
<li>
<p><code>reverse-menu-complete</code><br />
moves the mark to the previous match</p>
</li>
<li>
<p><code>vi-insert</code><br />
this toggles between normal and interactive mode; in interactive
mode the keys bound to <code>self-insert</code> and <code>self-insert-unmeta</code> insert
into the command line as in normal editing mode but without leaving
menu selection; after each character completion is tried again and
the list changes to contain only the new matches; the completion
widgets make the longest unambiguous string be inserted in the
command line and <code>undo</code> and <code>backward-delete-char</code> go back to the
previous set of matches</p>
</li>
<li>
<p><code>history-incremental-search-forward</code><br />
<code>history-incremental-search-backward</code><br />
this starts incremental searches in the list of completions
displayed; in this mode, <code>accept-line</code> only leaves incremental
search, going back to the normal menu selection mode</p>
</li>
</ul>
<p>All movement functions wrap around at the edges; any other zle function
not listed leaves menu selection and executes that function. It is
possible to make widgets in the above list do the same by using the form
of the widget with a ‘<code>.</code>’ in front. For example, the widget
‘<code>.accept-line</code>’ has the effect of leaving menu selection and
accepting the entire command line.</p>
<p>During this selection the widget uses the keymap <code>menuselect</code>. Any key
that is not defined in this keymap or that is bound to <code>undefined-key</code>
is looked up in the keymap currently selected. This is used to ensure
that the most important keys used during selection (namely the cursor
keys, return, and TAB) have sensible defaults. However, keys in the
<code>menuselect</code> keymap can be modified directly using the <code>bindkey</code> builtin
command (see <a href="Zsh-Modules.html#The-zsh_002fzle-Module">The zsh/zle Module</a>). For
example, to make the return key leave menu selection without accepting
the match currently selected one could call</p>
<div class="example">
<pre><code class="language-example">bindkey -M menuselect '^M' send-break
</code></pre>
</div>
<p>after loading the <code>zsh/complist</code> module.</p>
<hr />
<p><span id="The-zsh_002fcomputil-Module"></span>
<span id="The-zsh_002fcomputil-Module-1"></span></p>
<h2 id="228-the-zshcomputil-module"><a class="header" href="#228-the-zshcomputil-module">22.8 The zsh/computil Module</a></h2>
<p><span id="index-completion_002c-utility"></span></p>
<p>The <code>zsh/computil</code> module adds several builtin commands that are used by
some of the completion functions in the completion system based on shell
functions (see <a href="Completion-System.html#Completion-System">Completion
System</a> ). Except for
<code>compquote</code> these builtin commands are very specialised and thus not
very interesting when writing your own completion functions. In summary,
these builtin commands are:</p>
<p><span id="index-comparguments"></span></p>
<p><code>comparguments</code></p>
<p>This is used by the <code>_arguments</code> function to do the argument and command
line parsing. Like <code>compdescribe</code> it has an option <code>-i</code> to do the
parsing and initialize some internal state and various options to access
the state information to decide what should be completed.</p>
<p><span id="index-compdescribe"></span></p>
<p><code>compdescribe</code></p>
<p>This is used by the <code>_describe</code> function to build the displays for the
matches and to get the strings to add as matches with their options. On
the first call one of the options <code>-i</code> or <code>-I</code> should be supplied as the
first argument. In the first case, display strings without the
descriptions will be generated, in the second case, the string used to
separate the matches from their descriptions must be given as the second
argument and the descriptions (if any) will be shown. All other
arguments are like the definition arguments to <code>_describe</code> itself.</p>
<p>Once <code>compdescribe</code> has been called with either the <code>-i</code> or the <code>-I</code>
option, it can be repeatedly called with the <code>-g</code> option and the names
of four parameters as its arguments. This will step through the
different sets of matches and store the value of <code>compstate[list]</code> in
the first scalar, the options for <code>compadd</code> in the second array, the
matches in the third array, and the strings to be displayed in the
completion listing in the fourth array. The arrays may then be directly
given to <code>compadd</code> to register the matches with the completion code.</p>
<p><span id="index-compfiles"></span></p>
<p><code>compfiles</code></p>
<p>Used by the <code>_path_files</code> function to optimize complex recursive
filename generation (globbing). It does three things. With the <code>-p</code> and
<code>-P</code> options it builds the glob patterns to use, including the paths
already handled and trying to optimize the patterns with respect to the
prefix and suffix from the line and the match specification currently
used. The <code>-i</code> option does the directory tests for the <code>ignore-parents</code>
style and the <code>-r</code> option tests if a component for some of the matches
are equal to the string on the line and removes all other matches if
that is true.</p>
<p><span id="index-compgroups"></span></p>
<p><code>compgroups</code></p>
<p>Used by the <code>_tags</code> function to implement the internals of the
<code>group-order</code> style. This only takes its arguments as names of
completion groups and creates the groups for it (all six types: sorted
and unsorted, both without removing duplicates, with removing all
duplicates and with removing consecutive duplicates).</p>
<p><span id="index-compquote"></span></p>
<p><code>compquote</code> [ <code>-p</code> ] <code>names</code> ...</p>
<p>There may be reasons to write completion functions that have to add the
matches using the <code>-Q</code> option to <code>compadd</code> and perform quoting
themselves. Instead of interpreting the first character of the
<code>all_quotes</code> key of the <code>compstate</code> special association and using the
<code>q</code> flag for parameter expansions, one can use this builtin command. The
arguments are the names of scalar or array parameters and the values of
these parameters are quoted as needed for the innermost quoting level.
If the <code>-p</code> option is given, quoting is done as if there is some prefix
before the values of the parameters, so that a leading equal sign will
not be quoted.</p>
<p>The return status is non-zero in case of an error and zero otherwise.</p>
<p><span id="index-comptags"></span> <span id="index-comptry"></span></p>
<p><code>comptags</code></p>
<p><code>comptry</code></p>
<p>These implement the internals of the tags mechanism.</p>
<p><span id="index-compvalues"></span></p>
<p><code>compvalues</code></p>
<p>Like <code>comparguments</code>, but for the <code>_values</code> function.</p>
<hr />
<p><span id="The-zsh_002fcurses-Module"></span>
<span id="The-zsh_002fcurses-Module-1"></span></p>
<h2 id="229-the-zshcurses-module"><a class="header" href="#229-the-zshcurses-module">22.9 The zsh/curses Module</a></h2>
<p>The <code>zsh/curses</code> module makes available one builtin command and various
parameters.</p>
<hr />
<p><span id="Builtin"></span></p>
<h3 id="2291-builtin"><a class="header" href="#2291-builtin">22.9.1 Builtin</a></h3>
<p><span id="index-zcurses"></span>
<span id="index-windows_002c-curses"></span></p>
<p><code>zcurses</code> <code>init</code></p>
<p><code>zcurses</code> <code>end</code></p>
<p><code>zcurses</code> <code>addwin</code> <code>targetwin</code> <code>nlines</code> <code>ncols</code> <code>begin_y</code> <code>begin_x</code> [
<code>parentwin</code> ]</p>
<p><code>zcurses</code> <code>delwin</code> <code>targetwin</code></p>
<p><code>zcurses</code> <code>refresh</code> [ <code>targetwin</code> ... ]</p>
<p><code>zcurses</code> <code>touch</code> <code>targetwin</code> ...</p>
<p><code>zcurses</code> <code>move</code> <code>targetwin</code> <code>new_y</code> <code>new_x</code></p>
<p><code>zcurses</code> <code>clear</code> <code>targetwin</code> [ <code>redraw</code> | <code>eol</code> | <code>bot</code> ]</p>
<p><code>zcurses</code> <code>position</code> <code>targetwin</code> <code>array</code></p>
<p><code>zcurses</code> <code>char</code> <code>targetwin</code> <code>character</code></p>
<p><code>zcurses</code> <code>string</code> <code>targetwin</code> <code>string</code></p>
<p><code>zcurses</code> <code>border</code> <code>targetwin</code> <code>border</code></p>
<p><code>zcurses</code> <code>attr</code> <code>targetwin</code> [ [<code>+</code>|<code>-</code>]<code>attribute</code> |
<code>fg_col``/``bg_col</code> ] [...]</p>
<p><code>zcurses</code> <code>bg</code> <code>targetwin</code> [ [<code>+</code>|<code>-</code>]<code>attribute</code> |
<code>fg_col``/``bg_col</code> | <code>@``char</code> ] [...]</p>
<p><code>zcurses</code> <code>scroll</code> <code>targetwin</code> [ <code>on</code> | <code>off</code> | [<code>+</code>|<code>-</code>]<code>lines</code> ]</p>
<p><code>zcurses</code> <code>input</code> <code>targetwin</code> [ <code>param</code> [ <code>kparam</code> [ <code>mparam</code> ] ]
]</p>
<p><code>zcurses</code> <code>mouse</code> [ <code>delay</code> <code>num</code> | [<code>+</code>|<code>-</code>]<code>motion</code> ]</p>
<p><code>zcurses</code> <code>timeout</code> <code>targetwin</code> <code>intval</code></p>
<p><code>zcurses</code> <code>querychar</code> <code>targetwin</code> [ <code>param</code> ]</p>
<p><code>zcurses</code> <code>resize</code> <code>height</code> <code>width</code> [ <code>endwin</code> | <code>nosave</code> |
<code>endwin_nosave</code> ]</p>
<p>Manipulate curses windows. All uses of this command should be bracketed
by ‘<code>zcurses init</code>’ to initialise use of curses, and ‘<code>zcurses end</code>’ to
end it; omitting ‘<code>zcurses end</code>’ can cause the terminal to be in an
unwanted state.</p>
<p>The subcommand <code>addwin</code> creates a window with <code>nlines</code> lines and <code>ncols</code>
columns. Its upper left corner will be placed at row <code>begin_y</code> and
column <code>begin_x</code> of the screen. <code>targetwin</code> is a string and refers to
the name of a window that is not currently assigned. Note in particular
the curses convention that vertical values appear before horizontal
values.</p>
<p>If <code>addwin</code> is given an existing window as the final argument, the new
window is created as a subwindow of <code>parentwin</code>. This differs from an
ordinary new window in that the memory of the window contents is shared
with the parent’s memory. Subwindows must be deleted before their
parent. Note that the coordinates of subwindows are relative to the
screen, not the parent, as with other windows.</p>
<p>Use the subcommand <code>delwin</code> to delete a window created with <code>addwin</code>.
Note that <code>end</code> does <em>not</em> implicitly delete windows, and that <code>delwin</code>
does not erase the screen image of the window.</p>
<p>The window corresponding to the full visible screen is called <code>stdscr</code>;
it always exists after ‘<code>zcurses init</code>’ and cannot be delete with
<code>delwin</code>.</p>
<p>The subcommand <code>refresh</code> will refresh window <code>targetwin</code>; this is
necessary to make any pending changes (such as characters you have
prepared for output with <code>char</code>) visible on the screen. <code>refresh</code>
without an argument causes the screen to be cleared and redrawn. If
multiple windows are given, the screen is updated once at the end.</p>
<p>The subcommand <code>touch</code> marks the <code>targetwin</code>s listed as changed. This is
necessary before <code>refresh</code>ing windows if a window that was in front of
another window (which may be <code>stdscr</code>) is deleted.</p>
<p>The subcommand <code>move</code> moves the cursor position in <code>targetwin</code> to new
coordinates <code>new_y</code> and <code>new_x</code>. Note that the subcommand <code>string</code> (but
not the subcommand <code>char</code>) advances the cursor position over the
characters added.</p>
<p>The subcommand <code>clear</code> erases the contents of <code>targetwin</code>. One (and no
more than one) of three options may be specified. With the option
<code>redraw</code>, in addition the next <code>refresh</code> of <code>targetwin</code> will cause the
screen to be cleared and repainted. With the option <code>eol</code>, <code>targetwin</code>
is only cleared to the end of the current cursor line. With the option
<code>bot</code>, <code>targetwin</code> is cleared to the end of the window, i.e everything
to the right and below the cursor is cleared.</p>
<p>The subcommand <code>position</code> writes various positions associated with
<code>targetwin</code> into the array named <code>array</code>. These are, in order:</p>
<ul>
<li>
<p>-<br />
The y and x coordinates of the cursor relative to the top left of
<code>targetwin</code></p>
</li>
<li>
<p>-<br />
The y and x coordinates of the top left of <code>targetwin</code> on the screen</p>
</li>
<li>
<p>-<br />
The size of <code>targetwin</code> in y and x dimensions.</p>
</li>
</ul>
<p>Outputting characters and strings are achieved by <code>char</code> and <code>string</code>
respectively.</p>
<p>To draw a border around window <code>targetwin</code>, use <code>border</code>. Note that the
border is not subsequently handled specially: in other words, the border
is simply a set of characters output at the edge of the window. Hence it
can be overwritten, can scroll off the window, etc.</p>
<p>The subcommand <code>attr</code> will set <code>targetwin</code>’s attributes or
foreground/background color pair for any successive character output.
Each <code>attribute</code> given on the line may be prepended by a <code>+</code> to set or a
<code>-</code> to unset that attribute; <code>+</code> is assumed if absent. The attributes
supported are <code>blink</code>, <code>bold</code>, <code>dim</code>, <code>reverse</code>, <code>standout</code>, and
<code>underline</code>.</p>
<p>Each <code>fg_col``/``bg_col</code> attribute (to be read as ‘<code>fg_col</code> on
<code>bg_col</code>’) sets the foreground and background color for character
output. The color <code>default</code> is sometimes available (in particular if the
library is ncurses), specifying the foreground or background color with
which the terminal started. The color pair <code>default/default</code> is always
available. To use more than the 8 named colors (red, green, etc.)
construct the <code>fg_col``/``bg_col</code> pairs where <code>fg_col</code> and <code>bg_col</code> are
decimal integers, e.g <code>128/200</code>. The maximum color value is 254 if the
terminal supports 256 colors.</p>
<p><code>bg</code> overrides the color and other attributes of all characters in the
window. Its usual use is to set the background initially, but it will
overwrite the attributes of any characters at the time when it is
called. In addition to the arguments allowed with <code>attr</code>, an argument
<code>@``char</code> specifies a character to be shown in otherwise blank areas of
the window. Owing to limitations of curses this cannot be a multibyte
character (use of ASCII characters only is recommended). As the
specified set of attributes override the existing background, turning
attributes off in the arguments is not useful, though this does not
cause an error.</p>
<p>The subcommand <code>scroll</code> can be used with <code>on</code> or <code>off</code> to enabled or
disable scrolling of a window when the cursor would otherwise move below
the window due to typing or output. It can also be used with a positive
or negative integer to scroll the window up or down the given number of
lines without changing the current cursor position (which therefore
appears to move in the opposite direction relative to the window). In
the second case, if scrolling is <code>off</code> it is temporarily turned <code>on</code> to
allow the window to be scrolled.</p>
<p>The subcommand <code>input</code> reads a single character from the window without
echoing it back. If <code>param</code> is supplied the character is assigned to the
parameter <code>param</code>, else it is assigned to the parameter <code>REPLY</code>.</p>
<p>If both <code>param</code> and <code>kparam</code> are supplied, the key is read in ‘keypad’
mode. In this mode special keys such as function keys and arrow keys
return the name of the key in the parameter <code>kparam</code>. The key names are
the macros defined in the <code>curses.h</code> or <code>ncurses.h</code> with the prefix
‘<code>KEY_</code>’ removed; see also the description of the parameter
<code>zcurses_keycodes</code> below. Other keys cause a value to be set in <code>param</code>
as before. On a successful return only one of <code>param</code> or <code>kparam</code>
contains a non-empty string; the other is set to an empty string.</p>
<p>If <code>mparam</code> is also supplied, <code>input</code> attempts to handle mouse input.
This is only available with the ncurses library; mouse handling can be
detected by checking for the exit status of ‘<code>zcurses mouse</code>’ with no
arguments. If a mouse button is clicked (or double- or triple-clicked,
or pressed or released with a configurable delay from being clicked)
then <code>kparam</code> is set to the string <code>MOUSE</code>, and <code>mparam</code> is set to an
array consisting of the following elements:</p>
<ul>
<li>
<p>-<br />
An identifier to discriminate different input devices; this is only
rarely useful.</p>
</li>
<li>
<p>-<br />
The x, y and z coordinates of the mouse click relative to the full
screen, as three elements in that order (i.e. the y coordinate is,
unusually, after the x coordinate). The z coordinate is only
available for a few unusual input devices and is otherwise set to
zero.</p>
</li>
<li>
<p>-<br />
Any events that occurred as separate items; usually there will be
just one. An event consists of <code>PRESSED</code>, <code>RELEASED</code>, <code>CLICKED</code>,
<code>DOUBLE_CLICKED</code> or <code>TRIPLE_CLICKED</code> followed immediately (in the
same element) by the number of the button.</p>
</li>
<li>
<p>-<br />
If the shift key was pressed, the string <code>SHIFT</code>.</p>
</li>
<li>
<p>-<br />
If the control key was pressed, the string <code>CTRL</code>.</p>
</li>
<li>
<p>-<br />
If the alt key was pressed, the string <code>ALT</code>.</p>
</li>
</ul>
<p>Not all mouse events may be passed through to the terminal window; most
terminal emulators handle some mouse events themselves. Note that the
ncurses manual implies that using input both with and without mouse
handling may cause the mouse cursor to appear and disappear.</p>
<p>The subcommand <code>mouse</code> can be used to configure the use of the mouse.
There is no window argument; mouse options are global. ‘<code>zcurses mouse</code>’
with no arguments returns status 0 if mouse handling is possible, else
status 1. Otherwise, the possible arguments (which may be combined on
the same command line) are as follows. <code>delay</code> <code>num</code> sets the maximum
delay in milliseconds between press and release events to be considered
as a click; the value 0 disables click resolution, and the default is
one sixth of a second. <code>motion</code> proceeded by an optional ‘<code>+</code>’ (the
default) or <code>-</code> turns on or off reporting of mouse motion in addition to
clicks, presses and releases, which are always reported. However, it
appears reports for mouse motion are not currently implemented.</p>
<p>The subcommand <code>timeout</code> specifies a timeout value for input from
<code>targetwin</code>. If <code>intval</code> is negative, ‘<code>zcurses input</code>’ waits
indefinitely for a character to be typed; this is the default. If
<code>intval</code> is zero, ‘<code>zcurses input</code>’ returns immediately; if there is
typeahead it is returned, else no input is done and status 1 is
returned. If <code>intval</code> is positive, ‘<code>zcurses input</code>’ waits <code>intval</code>
milliseconds for input and if there is none at the end of that period
returns status 1.</p>
<p>The subcommand <code>querychar</code> queries the character at the current cursor
position. The return values are stored in the array named <code>param</code> if
supplied, else in the array <code>reply</code>. The first value is the character
(which may be a multibyte character if the system supports them); the
second is the color pair in the usual <code>fg_col``/``bg_col</code> notation, or
<code>0</code> if color is not supported. Any attributes other than color that
apply to the character, as set with the subcommand <code>attr</code>, appear as
additional elements.</p>
<p>The subcommand <code>resize</code> resizes <code>stdscr</code> and all windows to given
dimensions (windows that stick out from the new dimensions are resized
down). The underlying curses extension (<code>resize_term call</code>) can be
unavailable. To verify, zeroes can be used for <code>height</code> and <code>width</code>. If
the result of the subcommand is <code>0</code>, resize_term is available (<code>2</code>
otherwise). Tests show that resizing can be normally accomplished by
calling <code>zcurses end</code> and <code>zcurses refresh</code>. The <code>resize</code> subcommand is
provided for versatility. Multiple system configurations have been
checked and <code>zcurses end</code> and <code>zcurses refresh</code> are still needed for
correct terminal state after resize. To invoke them with <code>resize</code>, use
<code>endwin</code> argument. Using <code>nosave</code> argument will cause new terminal state
to not be saved internally by <code>zcurses</code>. This is also provided for
versatility and should normally be not needed.</p>
<hr />
<p><span id="Parameters-4"></span></p>
<h3 id="2292-parameters"><a class="header" href="#2292-parameters">22.9.2 Parameters</a></h3>
<p><span id="index-ZCURSES_005fCOLORS"></span></p>
<p><code>ZCURSES_COLORS</code></p>
<p>Readonly integer. The maximum number of colors the terminal supports.
This value is initialised by the curses library and is not available
until the first time <code>zcurses init</code> is run.</p>
<p><span id="index-ZCURSES_005fCOLOR_005fPAIRS"></span></p>
<p><code>ZCURSES_COLOR_PAIRS</code></p>
<p>Readonly integer. The maximum number of color pairs <code>fg_col``/``bg_col</code>
that may be defined in ‘<code>zcurses attr</code>’ commands; note this limit
applies to all color pairs that have been used whether or not they are
currently active. This value is initialised by the curses library and is
not available until the first time <code>zcurses init</code> is run.</p>
<p><span id="index-zcurses_005fattrs"></span></p>
<p><code>zcurses_attrs</code></p>
<p>Readonly array. The attributes supported by <code>zsh/curses</code>; available as
soon as the module is loaded.</p>
<p><span id="index-zcurses_005fcolors"></span></p>
<p><code>zcurses_colors</code></p>
<p>Readonly array. The colors supported by <code>zsh/curses</code>; available as soon
as the module is loaded.</p>
<p><span id="index-zcurses_005fkeycodes"></span></p>
<p><code>zcurses_keycodes</code></p>
<p>Readonly array. The values that may be returned in the second parameter
supplied to ‘<code>zcurses input</code>’ in the order in which they are defined
internally by curses. Not all function keys are listed, only <code>F0</code>;
curses reserves space for <code>F0</code> up to <code>F63</code>.</p>
<p><span id="index-zcurses_005fwindows"></span></p>
<p><code>zcurses_windows</code></p>
<p>Readonly array. The current list of windows, i.e. all windows that have
been created with ‘<code>zcurses addwin</code>’ and not removed with ‘<code>zcurses delwin</code>’.</p>
<hr />
<p><span id="The-zsh_002fdatetime-Module"></span>
<span id="The-zsh_002fdatetime-Module-1"></span></p>
<h2 id="2210-the-zshdatetime-module"><a class="header" href="#2210-the-zshdatetime-module">22.10 The zsh/datetime Module</a></h2>
<p>The <code>zsh/datetime</code> module makes available one builtin command:</p>
<p><span id="index-strftime"></span>
<span id="index-date-string_002c-printing"></span></p>
<p><code>strftime</code> [ <code>-s</code> <code>scalar</code> ] <code>format</code> [ <code>epochtime</code> [ <code>nanoseconds</code>
] ]</p>
<p><code>strftime</code> <code>-r</code> [ <code>-q</code> ] [ <code>-s</code> <code>scalar</code> ] <code>format</code> <code>timestring</code></p>
<p>Output the date in the <code>format</code> specified. With no <code>epochtime</code>, the
current system date/time is used; optionally, <code>epochtime</code> may be used to
specify the number of seconds since the epoch, and <code>nanoseconds</code> may
additionally be used to specify the number of nanoseconds past the
second (otherwise that number is assumed to be 0). See man page
strftime(3) for details. The zsh extensions described in <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a> are also available.</p>
<ul>
<li>
<p><code>-q</code><br />
Run quietly; suppress printing of all error messages described
below. Errors for invalid <code>epochtime</code> values are always printed.</p>
</li>
<li>
<p><code>-r</code><br />
With the option <code>-r</code> (reverse), use <code>format</code> to parse the input
string <code>timestring</code> and output the number of seconds since the epoch
at which the time occurred. The parsing is implemented by the system
function <code>strptime</code>; see man page strptime(3). This means that zsh
format extensions are not available, but for reverse lookup they are
not required.</p>
<p>In most implementations of <code>strftime</code> any timezone in the
<code>timestring</code> is ignored and the local timezone declared by the <code>TZ</code>
environment variable is used; other parameters are set to zero if
not present.</p>
<p>If <code>timestring</code> does not match <code>format</code> the command returns status 1
and prints an error message. If <code>timestring</code> matches <code>format</code> but
not all characters in <code>timestring</code> were used, the conversion
succeeds but also prints an error message.</p>
<p>If either of the system functions <code>strptime</code> or <code>mktime</code> is not
available, status 2 is returned and an error message is printed.</p>
</li>
<li>
<p><code>-s</code> <code>scalar</code><br />
Assign the date string (or epoch time in seconds if <code>-r</code> is given)
to <code>scalar</code> instead of printing it.</p>
</li>
</ul>
<p>Note that depending on the system’s declared integral time type,
<code>strftime</code> may produce incorrect results for epoch times greater than
2147483647 which corresponds to 2038-01-19 03:14:07 +0000.</p>
<p>The <code>zsh/datetime</code> module makes available several parameters; all are
readonly:</p>
<p><span id="index-EPOCHREALTIME"></span></p>
<p><code>EPOCHREALTIME</code></p>
<p>A floating point value representing the number of seconds since the
epoch. The notional accuracy is to nanoseconds if the <code>clock_gettime</code>
call is available and to microseconds otherwise, but in practice the
range of double precision floating point and shell scheduling latencies
may be significant effects.</p>
<p><span id="index-EPOCHSECONDS"></span></p>
<p><code>EPOCHSECONDS</code></p>
<p>An integer value representing the number of seconds since the epoch.</p>
<p><span id="index-epochtime"></span></p>
<p><code>epochtime</code></p>
<p>An array value containing the number of seconds since the epoch in the
first element and the remainder of the time since the epoch in
nanoseconds in the second element. To ensure the two elements are
consistent the array should be copied or otherwise referenced as a
single substitution before the values are used. The following idiom may
be used:</p>
<div class="example">
<pre><code class="language-example">for secs nsecs in $epochtime; do
...
done
</code></pre>
</div>
<hr />
<p><span id="The-zsh_002fdb_002fgdbm-Module"></span>
<span id="The-zsh_002fdb_002fgdbm-Module-1"></span></p>
<h2 id="2211-the-zshdbgdbm-module"><a class="header" href="#2211-the-zshdbgdbm-module">22.11 The zsh/db/gdbm Module</a></h2>
<p>The <code>zsh/db/gdbm</code> module is used to create &quot;tied&quot; associative arrays
that interface to database files. If the GDBM interface is not
available, the builtins defined by this module will report an error.
This module is also intended as a prototype for creating additional
database interfaces, so the <code>ztie</code> builtin may move to a more generic
module in the future.</p>
<p>The builtins in this module are:</p>
<p><span id="index-ztie"></span>
<span id="index-database-tied-array_002c-creating"></span></p>
<p><code>ztie -d db/gdbm -f</code> <code>filename</code> [ <code>-r</code> ] <code>arrayname</code></p>
<p>Open the GDBM database identified by <code>filename</code> and, if successful,
create the associative array <code>arrayname</code> linked to the file. To create a
local tied array, the parameter must first be declared, so commands
similar to the following would be executed inside a function scope:</p>
<div class="example">
<pre><code class="language-example">local -A sampledb
ztie -d db/gdbm -f sample.gdbm sampledb
</code></pre>
</div>
<p>The <code>-r</code> option opens the database file for reading only, creating a
parameter with the readonly attribute. Without this option, using
‘<code>ztie</code>’ on a file for which the user does not have write permission
is changed in <code>arrayname</code> are immediately written to <code>filename</code>.</p>
<p>Changes to the file modes <code>filename</code> after it has been opened do not
alter the state of <code>arrayname</code>, but ‘<code>typeset -r</code> <code>arrayname</code>’ works as
expected.</p>
<p><span id="index-zuntie"></span>
<span id="index-database-tied-array_002c-destroying"></span></p>
<p><code>zuntie</code> [ <code>-u</code> ] <code>arrayname</code> ...</p>
<p>Close the GDBM database associated with each <code>arrayname</code> and then unset
the parameter. The <code>-u</code> option forces an unset of parameters made
readonly with ‘<code>ztie -r</code>’.</p>
<p>This happens automatically if the parameter is explicitly unset or its
local scope (function) ends. Note that a readonly parameter may not be
explicitly unset, so the only way to unset a global parameter created
with ‘<code>ztie -r</code>’ is to use ‘<code>zuntie -u</code>’.</p>
<p><span id="index-zgdbmpath"></span>
<span id="index-database-file-path_002c-reading"></span></p>
<p><code>zgdbmpath</code> <code>parametername</code></p>
<p>Put path to database file assigned to <code>parametername</code> into <code>REPLY</code>
scalar.</p>
<p><span id="index-zgdbm_005ftied"></span>
<span id="index-database-tied-arrays_002c-enumerating"></span></p>
<p><code>zgdbm_tied</code></p>
<p>Array holding names of all tied parameters.</p>
<p>The fields of an associative array tied to GDBM are neither cached nor
otherwise stored in memory, they are read from or written to the
database on each reference. Thus, for example, the values in a readonly
array may be changed by a second writer of the same database file.</p>
<hr />
<p><span id="The-zsh_002fdeltochar-Module"></span>
<span id="The-zsh_002fdeltochar-Module-1"></span></p>
<h2 id="2212-the-zshdeltochar-module"><a class="header" href="#2212-the-zshdeltochar-module">22.12 The zsh/deltochar Module</a></h2>
<p>The <code>zsh/deltochar</code> module makes available two ZLE functions:</p>
<p><span id="index-delete_002dto_002dchar"></span></p>
<p><code>delete-to-char</code></p>
<p>Read a character from the keyboard, and delete from the cursor position
up to and including the next (or, with repeat count <code>n</code>, the <code>n</code>th)
instance of that character. Negative repeat counts mean delete
backwards.</p>
<p><span id="index-zap_002dto_002dchar"></span></p>
<p><code>zap-to-char</code></p>
<p>This behaves like <code>delete-to-char</code>, except that the final occurrence of
the character itself is not deleted.</p>
<hr />
<p><span id="The-zsh_002fexample-Module"></span>
<span id="The-zsh_002fexample-Module-1"></span></p>
<h2 id="2213-the-zshexample-module"><a class="header" href="#2213-the-zshexample-module">22.13 The zsh/example Module</a></h2>
<p>The <code>zsh/example</code> module makes available one builtin command:</p>
<p><span id="index-example"></span>
<span id="index-modules_002c-example"></span>
<span id="index-modules_002c-writing"></span>
<span id="index-writing-modules"></span></p>
<p><code>example</code> [ <code>-flags</code> ] [ <code>args</code> ... ]</p>
<p>Displays the flags and arguments it is invoked with.</p>
<p>The purpose of the module is to serve as an example of how to write a
module.</p>
<hr />
<p><span id="The-zsh_002ffiles-Module"></span>
<span id="The-zsh_002ffiles-Module-1"></span></p>
<h2 id="2214-the-zshfiles-module"><a class="header" href="#2214-the-zshfiles-module">22.14 The zsh/files Module</a></h2>
<p><span id="index-files_002c-manipulating"></span></p>
<p>The <code>zsh/files</code> module makes available some common commands for file
manipulation as builtins; these commands are probably not needed for
many normal situations but can be useful in emergency recovery
situations with constrained resources. The commands do not implement all
features now required by relevant standards committees.</p>
<p>For all commands, a variant beginning <code>zf_</code> is also available and loaded
automatically. Using the features capability of zmodload will let you
load only those names you want. Note that it’s possible to load only the
builtins with zsh-specific names using the following command:</p>
<div class="example">
<pre><code class="language-example">zmodload -m -F zsh/files b:zf_\*
</code></pre>
</div>
<p>The commands loaded by default are:</p>
<p><span id="index-chgrp"></span></p>
<p><code>chgrp</code> [ <code>-hRs</code> ] <code>group</code> <code>filename</code> ...</p>
<p>Changes group of files specified. This is equivalent to <code>chown</code> with a
<code>user-spec</code> argument of ‘<code>:``group</code>’.</p>
<p><span id="index-chmod"></span></p>
<p><code>chmod</code> [ <code>-Rs</code> ] <code>mode</code> <code>filename</code> ...</p>
<p>Changes mode of files specified.</p>
<p>The specified <code>mode</code> must be in octal.</p>
<p>The <code>-R</code> option causes <code>chmod</code> to recursively descend into directories,
changing the mode of all files in the directory after changing the mode
of the directory itself.</p>
<p>The <code>-s</code> option is a zsh extension to <code>chmod</code> functionality. It enables
paranoid behaviour, intended to avoid security problems involving a
<code>chmod</code> being tricked into affecting files other than the ones intended.
It will refuse to follow symbolic links, so that (for example)
‘‘<code>chmod 600 /tmp/foo/passwd</code>’’ can’t accidentally chmod
<code>/etc/passwd</code> if <code>/tmp/foo</code> happens to be a link to <code>/etc</code>. It will also
check where it is after leaving directories, so that a recursive chmod
of a deep directory tree can’t end up recursively chmoding <code>/usr</code> as a
result of directories being moved up the tree.</p>
<p><span id="index-chown"></span></p>
<p><code>chown</code> [ <code>-hRs</code> ] <code>user-spec</code> <code>filename</code> ...</p>
<p>Changes ownership and group of files specified.</p>
<p>The <code>user-spec</code> can be in four forms:</p>
<ul>
<li>
<p><code>user</code><br />
change owner to <code>user</code>; do not change group</p>
</li>
<li>
<p><code>user``::</code><br />
change owner to <code>user</code>; do not change group</p>
</li>
<li>
<p><code>user``:</code><br />
change owner to <code>user</code>; change group to <code>user</code>’s primary group</p>
</li>
<li>
<p><code>user``:``group</code><br />
change owner to <code>user</code>; change group to <code>group</code></p>
</li>
<li>
<p><code>:``group</code><br />
do not change owner; change group to <code>group</code></p>
</li>
</ul>
<p>In each case, the ‘<code>:</code>’ may instead be a ‘<code>.</code>’. The rule is that if
there is a ‘<code>:</code>’ then the separator is ‘<code>:</code>’, otherwise if there is a
‘<code>.</code>’ then the separator is ‘<code>.</code>’, otherwise there is no separator.</p>
<p>Each of <code>user</code> and <code>group</code> may be either a username (or group name, as
appropriate) or a decimal user ID (group ID). Interpretation as a name
takes precedence, if there is an all-numeric username (or group name).</p>
<p>If the target is a symbolic link, the <code>-h</code> option causes <code>chown</code> to set
the ownership of the link instead of its target.</p>
<p>The <code>-R</code> option causes <code>chown</code> to recursively descend into directories,
changing the ownership of all files in the directory after changing the
ownership of the directory itself.</p>
<p>The <code>-s</code> option is a zsh extension to <code>chown</code> functionality. It enables
paranoid behaviour, intended to avoid security problems involving a
<code>chown</code> being tricked into affecting files other than the ones intended.
It will refuse to follow symbolic links, so that (for example) ‘‘<code>chown luser /tmp/foo/passwd</code>’’ can’t accidentally chown <code>/etc/passwd</code> if
<code>/tmp/foo</code> happens to be a link to <code>/etc</code>. It will also check where it
is after leaving directories, so that a recursive chown of a deep
directory tree can’t end up recursively chowning <code>/usr</code> as a result of
directories being moved up the tree.</p>
<p><span id="index-ln"></span></p>
<p><code>ln</code> [ <code>-dfhins</code> ] <code>filename</code> <code>dest</code></p>
<p><code>ln</code> [ <code>-dfhins</code> ] <code>filename</code> ... <code>dir</code></p>
<p>Creates hard (or, with <code>-s</code>, symbolic) links. In the first form, the
specified <code>dest</code>ination is created, as a link to the specified
<code>filename</code>. In the second form, each of the <code>filename</code>s is taken in
turn, and linked to a pathname in the specified <code>dir</code>ectory that has the
same last pathname component.</p>
<p>Normally, <code>ln</code> will not attempt to create hard links to directories.
This check can be overridden using the <code>-d</code> option. Typically only the
super-user can actually succeed in creating hard links to directories.
This does not apply to symbolic links in any case.</p>
<p>By default, existing files cannot be replaced by links. The <code>-i</code> option
causes the user to be queried about replacing existing files. The <code>-f</code>
option causes existing files to be silently deleted, without querying.
<code>-f</code> takes precedence.</p>
<p>The <code>-h</code> and <code>-n</code> options are identical and both exist for
compatibility; either one indicates that if the target is a symlink then
it should not be dereferenced. Typically this is used in combination
with <code>-sf</code> so that if an existing link points to a directory then it
will be removed, instead of followed. If this option is used with
multiple filenames and the target is a symbolic link pointing to a
directory then the result is an error.</p>
<p><span id="index-mkdir"></span></p>
<p><code>mkdir</code> [ <code>-p</code> ] [ <code>-m</code> <code>mode</code> ] <code>dir</code> ...</p>
<p>Creates directories. With the <code>-p</code> option, non-existing parent
directories are first created if necessary, and there will be no
complaint if the directory already exists. The <code>-m</code> option can be used
to specify (in octal) a set of file permissions for the created
directories, otherwise mode 777 modified by the current <code>umask</code> (see man
page umask(2)) is used.</p>
<p><span id="index-mv"></span></p>
<p><code>mv</code> [ <code>-fi</code> ] <code>filename</code> <code>dest</code></p>
<p><code>mv</code> [ <code>-fi</code> ] <code>filename</code> ... <code>dir</code></p>
<p>Moves files. In the first form, the specified <code>filename</code> is moved to the
specified <code>dest</code>ination. In the second form, each of the <code>filename</code>s is
taken in turn, and moved to a pathname in the specified <code>dir</code>ectory that
has the same last pathname component.</p>
<p>By default, the user will be queried before replacing any file removed.
The <code>-i</code> option causes the user to be queried about replacing any
existing files. The <code>-f</code> option causes any existing files to be silently
deleted, without querying. <code>-f</code> takes precedence.</p>
<p>Note that this <code>mv</code> will not move files across devices. Historical
versions of <code>mv</code>, when actual renaming is impossible, fall back on
copying and removing files; if this behaviour is desired, use <code>cp</code> and
<code>rm</code> manually. This may change in a future version.</p>
<p><span id="index-rm"></span></p>
<p><code>rm</code> [ <code>-dfiRrs</code> ] <code>filename</code> ...</p>
<p>Removes files and directories specified.</p>
<p>Normally, <code>rm</code> will not remove directories (except with the <code>-R</code> or <code>-r</code>
options). The <code>-d</code> option causes <code>rm</code> to try removing directories with
<code>unlink</code> (see man page unlink(2)), the same method used for files.
Typically only the super-user can actually succeed in unlinking
directories in this way. <code>-d</code> takes precedence over <code>-R</code> and <code>-r</code>.</p>
<p>By default, the user will be queried before removing any file removed.
The <code>-i</code> option causes the user to be queried about removing any files.
The <code>-f</code> option causes files to be silently deleted, without querying,
and suppresses all error indications. <code>-f</code> takes precedence.</p>
<p>The <code>-R</code> and <code>-r</code> options cause <code>rm</code> to recursively descend into
directories, deleting all files in the directory before removing the
directory with the <code>rmdir</code> system call (see man page rmdir(2)).</p>
<p>The <code>-s</code> option is a zsh extension to <code>rm</code> functionality. It enables
paranoid behaviour, intended to avoid common security problems involving
a root-run <code>rm</code> being tricked into removing files other than the ones
intended. It will refuse to follow symbolic links, so that (for example)
‘‘<code>rm /tmp/foo/passwd</code>’’ can’t accidentally remove <code>/etc/passwd</code> if
<code>/tmp/foo</code> happens to be a link to <code>/etc</code>. It will also check where it
is after leaving directories, so that a recursive removal of a deep
directory tree can’t end up recursively removing <code>/usr</code> as a result of
directories being moved up the tree.</p>
<p><span id="index-rmdir"></span></p>
<p><code>rmdir</code> <code>dir</code> ...</p>
<p>Removes empty directories specified.</p>
<p><span id="index-sync"></span></p>
<p><code>sync</code></p>
<p>Calls the system call of the same name (see man page sync(2)), which
flushes dirty buffers to disk. It might return before the I/O has
actually been completed.</p>
<hr />
<p><span id="The-zsh_002flanginfo-Module"></span>
<span id="The-zsh_002flanginfo-Module-1"></span></p>
<h2 id="2215-the-zshlanginfo-module"><a class="header" href="#2215-the-zshlanginfo-module">22.15 The zsh/langinfo Module</a></h2>
<p>The <code>zsh/langinfo</code> module makes available one parameter:</p>
<p><span id="index-langinfo"></span></p>
<p><code>langinfo</code></p>
<p>An associative array that maps langinfo elements to their values.</p>
<p>Your implementation may support a number of the following keys:</p>
<p><code>CODESET</code>, <code>D_T_FMT</code>, <code>D_FMT</code>, <code>T_FMT</code>, <code>RADIXCHAR</code>, <code>THOUSEP</code>,
<code>YESEXPR</code>, <code>NOEXPR</code>, <code>CRNCYSTR</code>, <code>ABDAY_{1..7}</code>, <code>DAY_{1..7}</code>,
<code>ABMON_{1..12}</code>, <code>MON_{1..12}</code>, <code>T_FMT_AMPM</code>, <code>AM_STR</code>, <code>PM_STR</code>, <code>ERA</code>,
<code>ERA_D_FMT</code>, <code>ERA_D_T_FMT</code>, <code>ERA_T_FMT</code>, <code>ALT_DIGITS</code></p>
<hr />
<p><span id="The-zsh_002fmapfile-Module"></span>
<span id="The-zsh_002fmapfile-Module-1"></span></p>
<h2 id="2216-the-zshmapfile-module"><a class="header" href="#2216-the-zshmapfile-module">22.16 The zsh/mapfile Module</a></h2>
<p><span id="index-parameter_002c-file-access-via"></span></p>
<p>The <code>zsh/mapfile</code> module provides one special associative array
parameter of the same name.</p>
<p><span id="index-mapfile"></span></p>
<p><code>mapfile</code></p>
<p>This associative array takes as keys the names of files; the resulting
value is the content of the file. The value is treated identically to
any other text coming from a parameter. The value may also be assigned
to, in which case the file in question is written (whether or not it
originally existed); or an element may be unset, which will delete the
file in question. For example, ‘<code>vared mapfile[myfile]</code>’ works as
expected, editing the file ‘<code>myfile</code>’.</p>
<p>When the array is accessed as a whole, the keys are the names of files
in the current directory, and the values are empty (to save a huge
overhead in memory). Thus <code>${(k)mapfile}</code> has the same effect as the
glob operator <code>*(D)</code>, since files beginning with a dot are not special.
Care must be taken with expressions such as <code>rm ${(k)mapfile}</code>, which
will delete every file in the current directory without the usual ‘<code>rm *</code>’ test.</p>
<p>The parameter <code>mapfile</code> may be made read-only; in that case, files
referenced may not be written or deleted.</p>
<p>A file may conveniently be read into an array as one line per element
with the form ‘<code>array``=(&quot;${(f@)mapfile[``filename``]}&quot;)</code>’. The double
quotes and the ‘<code>@</code>’ are necessary to prevent empty lines from being
removed. Note that if the file ends with a newline, the shell will split
on the final newline, generating an additional empty field; this can be
suppressed by using
‘<code>array``=(&quot;${(f@)${mapfile[``filename``]%$’\n’}}&quot;)</code>’.</p>
<hr />
<p><span id="Limitations"></span></p>
<h3 id="22161-limitations"><a class="header" href="#22161-limitations">22.16.1 Limitations</a></h3>
<p>Although reading and writing of the file in question is efficiently
handled, zsh’s internal memory management may be arbitrarily baroque;
however, <code>mapfile</code> is usually very much more efficient than anything
involving a loop. Note in particular that the whole contents of the file
will always reside physically in memory when accessed (possibly multiple
times, due to standard parameter substitution operations). In
particular, this means handling of sufficiently long files (greater than
the machine’s swap space, or than the range of the pointer type) will be
incorrect.</p>
<p>No errors are printed or flagged for non-existent, unreadable, or
execution hierarchy to make this convenient.</p>
<p>It is unfortunate that the mechanism for loading modules does not yet
allow the user to specify the name of the shell parameter to be given
the special behaviour.</p>
<hr />
<p><span id="The-zsh_002fmathfunc-Module"></span>
<span id="The-zsh_002fmathfunc-Module-1"></span></p>
<h2 id="2217-the-zshmathfunc-module"><a class="header" href="#2217-the-zshmathfunc-module">22.17 The zsh/mathfunc Module</a></h2>
<p><span id="index-functions_002c-mathematical"></span>
<span id="index-mathematical-functions"></span></p>
<p>The <code>zsh/mathfunc</code> module provides standard mathematical functions for
use when evaluating mathematical formulae. The syntax agrees with normal
C and FORTRAN conventions, for example,</p>
<div class="example">
<pre><code class="language-example">(( f = sin(0.3) ))
</code></pre>
</div>
<p>assigns the sine of 0.3 to the parameter f.</p>
<p>Most functions take floating point arguments and return a floating point
value. However, any necessary conversions from or to integer type will
be performed automatically by the shell. Apart from <code>atan</code> with a second
argument and the <code>abs</code>, <code>int</code> and <code>float</code> functions, all functions
behave as noted in the manual page for the corresponding C function,
except that any arguments out of range for the function in question will
be detected by the shell and an error reported.</p>
<p>The following functions take a single floating point argument: <code>acos</code>,
<code>acosh</code>, <code>asin</code>, <code>asinh</code>, <code>atan</code>, <code>atanh</code>, <code>cbrt</code>, <code>ceil</code>, <code>cos</code>,
<code>cosh</code>, <code>erf</code>, <code>erfc</code>, <code>exp</code>, <code>expm1</code>, <code>fabs</code>, <code>floor</code>, <code>gamma</code>, <code>j0</code>,
<code>j1</code>, <code>lgamma</code>, <code>log</code>, <code>log10</code>, <code>log1p</code>, <code>log2</code>, <code>logb</code>, <code>sin</code>, <code>sinh</code>,
<code>sqrt</code>, <code>tan</code>, <code>tanh</code>, <code>y0</code>, <code>y1</code>. The <code>atan</code> function can optionally
take a second argument, in which case it behaves like the C function
<code>atan2</code>. The <code>ilogb</code> function takes a single floating point argument,
but returns an integer.</p>
<p>The function <code>signgam</code> takes no arguments, and returns an integer, which
is the C variable of the same name, as described in man page gamma(3).
Note that it is therefore only useful immediately after a call to
<code>gamma</code> or <code>lgamma</code>. Note also that ‘<code>signgam()</code>’ and ‘<code>signgam</code>’ are
distinct expressions.</p>
<p>The functions <code>min</code>, <code>max</code>, and <code>sum</code> are defined not in this module but
in the <code>zmathfunc</code> autoloadable function, described in <a href="User-Contributions.html#Mathematical-Functions">Mathematical
Functions</a>.</p>
<p>The following functions take two floating point arguments: <code>copysign</code>,
<code>fmod</code>, <code>hypot</code>, <code>nextafter</code>.</p>
<p>The following take an integer first argument and a floating point second
argument: <code>jn</code>, <code>yn</code>.</p>
<p>The following take a floating point first argument and an integer second
argument: <code>ldexp</code>, <code>scalb</code>.</p>
<p>The function <code>abs</code> does not convert the type of its single argument; it
returns the absolute value of either a floating point number or an
integer. The functions <code>float</code> and <code>int</code> convert their arguments into a
floating point or integer value (by truncation) respectively.</p>
<p>Note that the C <code>pow</code> function is available in ordinary math evaluation
as the ‘<code>**</code>’ operator and is not provided here.</p>
<p>The function <code>rand48</code> is available if your system’s mathematical library
has the function <code>erand48(3)</code>. It returns a pseudo-random floating point
number between 0 and 1. It takes a single string optional argument.</p>
<p>If the argument is not present, the random number seed is initialised by
three calls to the <code>rand(3)</code> function — this produces the same random
numbers as the next three values of <code>$RANDOM</code>.</p>
<p>If the argument is present, it gives the name of a scalar parameter
where the current random number seed will be stored. On the first call,
the value must contain at least twelve hexadecimal digits (the remainder
of the string is ignored), or the seed will be initialised in the same
manner as for a call to <code>rand48</code> with no argument. Subsequent calls to
<code>rand48</code>(<code>param</code>) will then maintain the seed in the parameter <code>param</code>
as a string of twelve hexadecimal digits, with no base signifier. The
random number sequences for different parameters are completely
independent, and are also independent from that used by calls to
<code>rand48</code> with no argument.</p>
<p>For example, consider</p>
<div class="example">
<pre><code class="language-example">print $(( rand48(seed) ))
print $(( rand48() ))
print $(( rand48(seed) ))
</code></pre>
</div>
<p>Assuming <code>$seed</code> does not exist, it will be initialised by the first
call. In the second call, the default seed is initialised; note,
however, that because of the properties of <code>rand()</code> there is a
correlation between the seeds used for the two initialisations, so for
more secure uses, you should generate your own 12-byte seed. The third
call returns to the same sequence of random numbers used in the first
call, unaffected by the intervening <code>rand48()</code>.</p>
<hr />
<p><span id="The-zsh_002fnearcolor-Module"></span>
<span id="The-zsh_002fnearcolor-Module-1"></span></p>
<h2 id="2218-the-zshnearcolor-module"><a class="header" href="#2218-the-zshnearcolor-module">22.18 The zsh/nearcolor Module</a></h2>
<p>The <code>zsh/nearcolor</code> module replaces colours specified as hex triplets
with the nearest colour in the 88 or 256 colour palettes that are widely
used by terminal emulators. By default, 24-bit true colour escape codes
are generated when colours are specified using hex triplets. These are
not supported by all terminals. The purpose of this module is to make it
easier to define colour preferences in a form that can work across a
range of terminal emulators.</p>
<p>Aside from the default colour, the ANSI standard for terminal escape
codes provides for eight colours. The bright attribute brings this to
sixteen. These basic colours are commonly used in terminal applications
due to being widely supported. Expanded 88 and 256 colour palettes are
also common and, while the first sixteen colours vary somewhat between
terminals and configurations, these add a generally consistent and</p>
<p>In order to use the <code>zsh/nearcolor</code> module, it only needs to be loaded.
Thereafter, whenever a colour is specified using a hex triplet, it will
be compared against each of the available colours and the closest will
be selected. The first sixteen colours are never matched in</p>
<p>It isn’t possible to reliably detect support for true colour in the
terminal emulator. It is therefore recommended to be selective in
loading the <code>zsh/nearcolor</code> module. For example, the following checks
the <code>COLORTERM</code> environment variable:</p>
<div class="example">
<pre><code class="language-example">[[ $COLORTERM = *(24bit|truecolor)* ]] || zmodload zsh/nearcolor
</code></pre>
</div>
<p>Note that some terminals accept the true color escape codes but map them
internally to a more limited palette in a similar manner to the
<code>zsh/nearcolor</code> module.</p>
<hr />
<p><span id="The-zsh_002fnewuser-Module"></span>
<span id="The-zsh_002fnewuser-Module-1"></span></p>
<h2 id="2219-the-zshnewuser-module"><a class="header" href="#2219-the-zshnewuser-module">22.19 The zsh/newuser Module</a></h2>
<p>The <code>zsh/newuser</code> module is loaded at boot if it is available, the <code>RCS</code>
option is set, and the <code>PRIVILEGED</code> option is not set (all three are
true by default). This takes place immediately after commands in the
global <code>zshenv</code> file (typically <code>/etc/zshenv</code>), if any, have been
executed. If the module is not available it is silently ignored by the
shell; the module may safely be removed from <code>$MODULE_PATH</code> by the
administrator if it is not required.</p>
<p>On loading, the module tests if any of the start-up files <code>.zshenv</code>,
<code>.zprofile</code>, <code>.zshrc</code> or <code>.zlogin</code> exist in the directory given by the
environment variable <code>ZDOTDIR</code>, or the user’s home directory if that is
not set. The test is not performed and the module halts processing if
the shell was in an emulation mode (i.e. had been invoked as some other
shell than zsh).</p>
<p>If none of the start-up files were found, the module then looks for the
file <code>newuser</code> first in a sitewide directory, usually the parent
directory of the <code>site-functions</code> directory, and if that is not found
the module searches in a version-specific directory, usually the parent
of the <code>functions</code> directory containing version-specific functions.
(These directories can be configured when zsh is built using the
<code>–enable-site-scriptdir=``dir</code> and <code>–enable-scriptdir=``dir</code> flags to
<code>configure</code>, respectively; the defaults are <code>prefix``/share/zsh</code> and
<code>prefix``/share/zsh/$ZSH_VERSION</code> where the default <code>prefix</code> is
<code>/usr/local</code>.)</p>
<p>If the file <code>newuser</code> is found, it is then sourced in the same manner as
a start-up file. The file is expected to contain code to install
start-up files for the user, however any valid shell code will be
executed.</p>
<p>The <code>zsh/newuser</code> module is then unconditionally unloaded.</p>
<p>Note that it is possible to achieve exactly the same effect as the
<code>zsh/newuser</code> module by adding code to <code>/etc/zshenv</code>. The module exists
simply to allow the shell to make arrangements for new users without the
need for intervention by package maintainers and system administrators.</p>
<p>The script supplied with the module invokes the shell function
<code>zsh-newuser-install</code>. This may be invoked directly by the user even if
the <code>zsh/newuser</code> module is disabled. Note, however, that if the module
is not installed the function will not be installed either. The function
is documented in <a href="User-Contributions.html#User-Configuration-Functions">User Configuration
Functions</a>.</p>
<hr />
<p><span id="The-zsh_002fparameter-Module"></span>
<span id="The-zsh_002fparameter-Module-1"></span></p>
<h2 id="2220-the-zshparameter-module"><a class="header" href="#2220-the-zshparameter-module">22.20 The zsh/parameter Module</a></h2>
<p><span id="index-parameters_002c-special-1"></span></p>
<p>The <code>zsh/parameter</code> module gives access to some of the internal hash</p>
<p><span id="index-options-1"></span></p>
<p><code>options</code></p>
<p>The keys for this associative array are the names of the options that
can be set and unset using the <code>setopt</code> and <code>unsetopt</code> builtins. The
value of each key is either the string <code>on</code> if the option is currently
set, or the string <code>off</code> if the option is unset. Setting a key to one of
these strings is like setting or unsetting the option, respectively.
Unsetting a key in this array is like setting it to the value <code>off</code>.</p>
<p><span id="index-commands"></span></p>
<p><code>commands</code></p>
<p>names of external commands, the values are the pathnames of the files
that would be executed when the command would be invoked. Setting a with
the <code>hash</code> builtin. Unsetting a key as in ‘<code>unset &quot;commands[foo]&quot;</code>’
removes the entry for the given key from the command</p>
<p><span id="index-functions-2"></span></p>
<p><code>functions</code></p>
<p>This associative array maps names of enabled functions to their
definitions. Setting a key in it is like defining a function with the
name given by the key and the body given by the value. Unsetting a key
removes the definition for the function named by the key.</p>
<p><span id="index-dis_005ffunctions"></span></p>
<p><code>dis_functions</code></p>
<p>Like <code>functions</code> but for disabled functions.</p>
<p><span id="index-functions_005fsource"></span></p>
<p><code>functions_source</code></p>
<p>This readonly associative array maps names of enabled functions to the
name of the file containing the source of the function.</p>
<p>For an autoloaded function that has already been loaded, or marked for
autoload with an absolute path, or that has had its path resolved with
‘<code>functions -r</code>’, this is the file found for autoloading, resolved to
an absolute path.</p>
<p>For a function defined within the body of a script or sourced file, this
is the name of that file. In this case, this is the exact path
originally used to that file, which may be a relative path.</p>
<p>For any other function, including any defined at an interactive prompt
or an autoload function whose path has not yet been resolved, this is
the empty string. However, the hash element is reported as defined just
so long as the function is present: the keys to this hash are the same
as those to <code>$functions</code>.</p>
<p><span id="index-dis_005ffunctions_005fsource"></span></p>
<p><code>dis_functions_source</code></p>
<p>Like <code>functions_source</code> but for disabled functions.</p>
<p><span id="index-builtins"></span></p>
<p><code>builtins</code></p>
<p>This associative array gives information about the builtin commands
currently enabled. The keys are the names of the builtin commands and
the values are either ‘<code>undefined</code>’ for builtin commands that will
automatically be loaded from a module if invoked or ‘<code>defined</code>’ for
builtin commands that are already loaded.</p>
<p><span id="index-dis_005fbuiltins"></span></p>
<p><code>dis_builtins</code></p>
<p>Like <code>builtins</code> but for disabled builtin commands.</p>
<p><span id="index-reswords"></span></p>
<p><code>reswords</code></p>
<p>This array contains the enabled reserved words.</p>
<p><span id="index-dis_005freswords"></span></p>
<p><code>dis_reswords</code></p>
<p>Like <code>reswords</code> but for disabled reserved words.</p>
<p><span id="index-patchars"></span></p>
<p><code>patchars</code></p>
<p>This array contains the enabled pattern characters.</p>
<p><span id="index-dis_005fpatchars"></span></p>
<p><code>dis_patchars</code></p>
<p>Like <code>patchars</code> but for disabled pattern characters.</p>
<p><span id="index-aliases"></span></p>
<p><code>aliases</code></p>
<p>This maps the names of the regular aliases currently enabled to their
expansions.</p>
<p><span id="index-dis_005faliases"></span></p>
<p><code>dis_aliases</code></p>
<p>Like <code>aliases</code> but for disabled regular aliases.</p>
<p><span id="index-galiases"></span></p>
<p><code>galiases</code></p>
<p>Like <code>aliases</code>, but for global aliases.</p>
<p><span id="index-dis_005fgaliases"></span></p>
<p><code>dis_galiases</code></p>
<p>Like <code>galiases</code> but for disabled global aliases.</p>
<p><span id="index-saliases"></span></p>
<p><code>saliases</code></p>
<p>Like <code>raliases</code>, but for suffix aliases.</p>
<p><span id="index-dis_005fsaliases"></span></p>
<p><code>dis_saliases</code></p>
<p>Like <code>saliases</code> but for disabled suffix aliases.</p>
<p><span id="index-parameters-1"></span></p>
<p><code>parameters</code></p>
<p>The keys in this associative array are the names of the parameters
currently defined. The values are strings describing the type of the
parameter, in the same format used by the <code>t</code> parameter flag, see
<a href="Expansion.html#Parameter-Expansion">Parameter Expansion</a> . Setting or
unsetting keys in this array is not possible.</p>
<p><span id="index-modules-1"></span></p>
<p><code>modules</code></p>
<p>An associative array giving information about modules. The keys are the
names of the modules loaded, registered to be autoloaded, or aliased.
The value says which state the named module is in and is one of the
strings ‘<code>loaded</code>’, ‘<code>autoloaded</code>’, or ‘<code>alias:``name</code>’, where <code>name</code> is
the name the module is aliased to.</p>
<p>Setting or unsetting keys in this array is not possible.</p>
<p><span id="index-dirstack"></span></p>
<p><code>dirstack</code></p>
<p>A normal array holding the elements of the directory stack. Note that
the output of the <code>dirs</code> builtin command includes one more directory,
the current working directory.</p>
<p><span id="index-history-2"></span></p>
<p><code>history</code></p>
<p>This associative array maps history event numbers to the full history
lines. Although it is presented as an associative array, the array of
all values (<code>${history[@]}</code>) is guaranteed to be returned in order from
most recent to oldest history event, that is, by decreasing history
event number.</p>
<p><span id="index-historywords"></span></p>
<p><code>historywords</code></p>
<p>A special array containing the words stored in the history. These also
appear in most to least recent order.</p>
<p><span id="index-jobdirs"></span></p>
<p><code>jobdirs</code></p>
<p>This associative array maps job numbers to the directories from which
the job was started (which may not be the current directory of the job).</p>
<p>The keys of the associative arrays are usually valid job numbers, and
these are the values output with, for example, <code>${(k)jobdirs}</code>.
Non-numeric job references may be used when looking up a value; for
example, <code>${jobdirs[%+]}</code> refers to the current job.</p>
<p><span id="index-jobtexts"></span></p>
<p><code>jobtexts</code></p>
<p>This associative array maps job numbers to the texts of the command
lines that were used to start the jobs.</p>
<p>Handling of the keys of the associative array is as described for
<code>jobdirs</code> above.</p>
<p><span id="index-jobstates"></span></p>
<p><code>jobstates</code></p>
<p>This associative array gives information about the states of the jobs
currently known. The keys are the job numbers and the values are strings
of the form ‘<code>job-state``:``mark``:``pid``=``state</code>...’. The <code>job-state</code>
gives the state the whole job is currently in, one of ‘<code>running</code>’,
‘<code>suspended</code>’, or ‘<code>done</code>’. The <code>mark</code> is ‘<code>+</code>’ for the current job,
‘<code>-</code>’ for the previous job and empty otherwise. This is followed by
one ‘<code>:``pid``=``state</code>’ for every process in the job. The <code>pid</code>s are,
of course, the process IDs and the <code>state</code> describes the state of that
process.</p>
<p>Handling of the keys of the associative array is as described for
<code>jobdirs</code> above.</p>
<p><span id="index-nameddirs"></span></p>
<p><code>nameddirs</code></p>
<p>This associative array maps the names of named directories to the
pathnames they stand for.</p>
<p><span id="index-userdirs"></span></p>
<p><code>userdirs</code></p>
<p>This associative array maps user names to the pathnames of their home
directories.</p>
<p><span id="index-usergroups"></span></p>
<p><code>usergroups</code></p>
<p>This associative array maps names of system groups of which the current
user is a member to the corresponding group identifiers. The contents
are the same as the groups output by the <code>id</code> command.</p>
<p><span id="index-funcfiletrace"></span></p>
<p><code>funcfiletrace</code></p>
<p>This array contains the absolute line numbers and corresponding file
names for the point where the current function, sourced file, or (if
<code>EVAL_LINENO</code> is set) <code>eval</code> command was called. The array is of the
same length as <code>funcsourcetrace</code> and <code>functrace</code>, but differs from
<code>funcsourcetrace</code> in that the line and file are the point of call, not
the point of definition, and differs from <code>functrace</code> in that all values
are absolute line numbers in files, rather than relative to the start of
a function, if any.</p>
<p><span id="index-funcsourcetrace"></span></p>
<p><code>funcsourcetrace</code></p>
<p>This array contains the file names and line numbers of the points where
the functions, sourced files, and (if <code>EVAL_LINENO</code> is set) <code>eval</code>
commands currently being executed were defined. The line number is the
line where the ‘<code>function</code> <code>name</code>’ or ‘<code>name</code> <code>()</code>’ started. In the case
of an autoloaded function the line number is reported as zero. The
format of each element is <code>filename``:``lineno</code>.</p>
<p>For functions autoloaded from a file in native zsh format, where only
the body of the function occurs in the file, or for files that have been
executed by the <code>source</code> or ‘<code>.</code>’ builtins, the trace information is
shown as <code>filename``:``0</code>, since the entire file is the definition. The
source file name is resolved to an absolute path when the function is
loaded or the path to it otherwise resolved.</p>
<p>Most users will be interested in the information in the <code>funcfiletrace</code>
array instead.</p>
<p><span id="index-funcstack"></span></p>
<p><code>funcstack</code></p>
<p>This array contains the names of the functions, sourced files, and (if
<code>EVAL_LINENO</code> is set) <code>eval</code> commands. currently being executed. The
first element is the name of the function using the parameter.</p>
<p>The standard shell array <code>zsh_eval_context</code> can be used to determine the
type of shell construct being executed at each depth: note, however,
that is in the opposite order, with the most recent item last, and it is
more detailed, for example including an entry for <code>toplevel</code>, the main
shell code being executed either interactively or from a script, which
is not present in <code>$funcstack</code>.</p>
<p><span id="index-functrace"></span></p>
<p><code>functrace</code></p>
<p>This array contains the names and line numbers of the callers
corresponding to the functions currently being executed. The format of
each element is <code>name``:``lineno</code>. Callers are also shown for sourced
files; the caller is the point where the <code>source</code> or ‘<code>.</code>’ command was
executed.</p>
<hr />
<p><span id="The-zsh_002fpcre-Module"></span>
<span id="The-zsh_002fpcre-Module-1"></span></p>
<h2 id="2221-the-zshpcre-module"><a class="header" href="#2221-the-zshpcre-module">22.21 The zsh/pcre Module</a></h2>
<p><span id="index-regular-expressions_002c-perl_002dcompatible"></span></p>
<p>The <code>zsh/pcre</code> module makes some commands available as builtins:</p>
<p><span id="index-pcre_005fcompile"></span></p>
<p><code>pcre_compile</code> [ <code>-aimxs</code> ] <code>PCRE</code></p>
<p>Compiles a perl-compatible regular expression.</p>
<p>Option <code>-a</code> will force the pattern to be anchored. Option <code>-i</code> will
compile a case-insensitive pattern. Option <code>-m</code> will compile a
multi-line pattern; that is, <code>^</code> and <code>$</code> will match newlines within the
pattern. Option <code>-x</code> will compile an extended pattern, wherein
whitespace and <code>#</code> comments are ignored. Option <code>-s</code> makes the dot
metacharacter match all characters, including those that indicate
newline.</p>
<p><span id="index-pcre_005fstudy"></span></p>
<p><code>pcre_study</code></p>
<p>Studies the previously-compiled PCRE which may result in faster
matching.</p>
<p><span id="index-pcre_005fmatch"></span></p>
<p><code>pcre_match</code> [ <code>-v</code> <code>var</code> ] [ <code>-a</code> <code>arr</code> ] [ <code>-n</code> <code>offset</code> ] [
<code>-b</code> ] <code>string</code></p>
<p>Returns successfully if <code>string</code> matches the previously-compiled PCRE.</p>
<p>Upon successful match, if the expression captures substrings within
parentheses, <code>pcre_match</code> will set the array <code>match</code> to those
substrings, unless the <code>-a</code> option is given, in which case it will set
the array <code>arr</code>. Similarly, the variable <code>MATCH</code> will be set to the
entire matched portion of the string, unless the <code>-v</code> option is given,
in which case the variable <code>var</code> will be set. No variables are altered
if there is no successful match. A <code>-n</code> option starts searching for a
match from the byte <code>offset</code> position in <code>string</code>. If the <code>-b</code> option is
given, the variable <code>ZPCRE_OP</code> will be set to an offset pair string,
representing the byte offset positions of the entire matched portion
within the <code>string</code>. For example, a <code>ZPCRE_OP</code> set to &quot;32 45&quot; indicates
that the matched portion began on byte offset 32 and ended on byte
offset 44. Here, byte offset position 45 is the position directly after
the matched portion. Keep in mind that the byte position isn’t
necessarily the same as the character position when UTF-8 characters are
involved. Consequently, the byte offset positions are only to be relied
on in the context of using them for subsequent searches on <code>string</code>,
using an offset position as an argument to the <code>-n</code> option. This is
mostly used to implement the &quot;find all non-overlapping matches&quot;
functionality.</p>
<p>A simple example of &quot;find all non-overlapping matches&quot;:</p>
<div class="example">
<pre><code class="language-example">string=&quot;The following zip codes: 78884 90210 99513&quot;
pcre_compile -m &quot;\d{5}&quot;
accum=()
pcre_match -b -- $string
while [[ $? -eq 0 ]] do
b=($=ZPCRE_OP)
accum+=$MATCH
pcre_match -b -n $b[2] -- $string
done
print -l $accum
</code></pre>
</div>
<p>The <code>zsh/pcre</code> module makes available the following test condition:</p>
<p><span id="index-pcre_002dmatch"></span></p>
<p><code>expr</code> <code>-pcre-match</code> <code>pcre</code></p>
<p>Matches a string against a perl-compatible regular expression.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">[[ &quot;$text&quot; -pcre-match ^d+$ ]] &amp;&amp;
print text variable contains only &quot;d's&quot;.
</code></pre>
</div>
<p><span id="index-REMATCH_005fPCRE-1"></span>
<span id="index-NO_005fCASE_005fMATCH-1"></span></p>
<p>If the <code>REMATCH_PCRE</code> option is set, the <code>=~</code> operator is equivalent to
<code>-pcre-match</code>, and the <code>NO_CASE_MATCH</code> option may be used. Note that
<code>NO_CASE_MATCH</code> never applies to the <code>pcre_match</code> builtin, instead use
the <code>-i</code> switch of <code>pcre_compile</code>.</p>
<hr />
<p><span id="The-zsh_002fparam_002fprivate-Module"></span>
<span id="The-zsh_002fparam_002fprivate-Module-1"></span></p>
<h2 id="2222-the-zshparamprivate-module"><a class="header" href="#2222-the-zshparamprivate-module">22.22 The zsh/param/private Module</a></h2>
<p>The <code>zsh/param/private</code> module is used to create parameters whose scope
is limited to the current function body, and <em>not</em> to other functions
called by the current function.</p>
<p>This module provides a single autoloaded builtin:</p>
<p><span id="index-private"></span>
<span id="index-private-parameter_002c-creating"></span></p>
<p><code>private</code> [ {<code>+</code>|<code>-</code>}<code>AHUahlprtux</code> ] [ {<code>+</code>|<code>-</code>}<code>EFLRZi</code> [ <code>n</code> ] ]
[ <code>name</code>[<code>=``value</code>] ... ]</p>
<p>The <code>private</code> builtin accepts all the same options and arguments as
<code>local</code> (<a href="Shell-Builtin-Commands.html#Shell-Builtin-Commands">Shell Builtin
Commands</a>) except
for the ‘<code>-``T</code>’ option. Tied parameters may not be made private.</p>
<p>If used at the top level (outside a function scope), <code>private</code> creates a
normal parameter in the same manner as <code>declare</code> or <code>typeset</code>. A warning
about this is printed if <code>WARN_CREATE_GLOBAL</code> is set
(<a href="Options.html#Options">Options</a>). Used inside a function scope,
<code>private</code> creates a local parameter similar to one declared with
<code>local</code>, except having special properties noted below.</p>
<p>Special parameters which expose or manipulate internal shell state, such
as <code>ARGC</code>, <code>argv</code>, <code>COLUMNS</code>, <code>LINES</code>, <code>UID</code>, <code>EUID</code>, <code>IFS</code>, <code>PROMPT</code>,
<code>RANDOM</code>, <code>SECONDS</code>, etc., cannot be made private unless the ‘<code>-``h</code>’
option is used to hide the special meaning of the parameter. This may
change in the future.</p>
<p>As with other <code>typeset</code> equivalents, <code>private</code> is both a builtin and a
reserved word, so arrays may be assigned with parenthesized word list
<code>name``=(``value</code>...<code>)</code> syntax. However, the reserved word ‘<code>private</code>’
is not available until <code>zsh/param/private</code> is loaded, so care must be
taken with order of execution and parsing for function definitions which
use <code>private</code>. To compensate for this, the module also adds the option
‘<code>-P</code>’ to the ‘<code>local</code>’ builtin to declare private parameters.</p>
<p>For example, this construction fails if <code>zsh/param/private</code> has not yet
been loaded when ‘<code>bad_declaration</code>’ is defined:</p>
<div class="example">
<pre><code class="language-example">bad_declaration() {
zmodload zsh/param/private
private array=( one two three )
}
</code></pre>
</div>
<p>This construction works because <code>local</code> is already a keyword, and the
module is loaded before the statement is executed:</p>
<div class="example">
<pre><code class="language-example">good_declaration() {
zmodload zsh/param/private
local -P array=( one two three )
}
</code></pre>
</div>
<p>The following is usable in scripts but may have trouble with <code>autoload</code>:</p>
<div class="example">
<pre><code class="language-example">zmodload zsh/param/private
iffy_declaration() {
private array=( one two three )
}
</code></pre>
</div>
<p>The <code>private</code> builtin may always be used with scalar assignments and for
declarations without assignments.</p>
<p>Parameters declared with <code>private</code> have the following properties:</p>
<ul>
<li>Within the function body where it is declared, the parameter behaves
as a local, except as noted above for tied or special parameters.</li>
<li>The type of a parameter declared private cannot be changed in the
scope where it was declared, even if the parameter is unset. Thus an
array cannot be assigned to a private scalar, etc.</li>
<li>Within any other function called by the declaring function, the
private parameter does <em>NOT</em> hide other parameters of the same name,
so for example a global parameter of the same name is visible and
may be assigned or unset. This includes calls to anonymous
functions, although that may also change in the future.</li>
<li>An exported private remains in the environment of inner scopes but
appears unset for the current shell in those scopes. Generally,
exporting private parameters should be avoided.</li>
</ul>
<p>Note that this differs from the static scope defined by compiled
languages derived from C, in that the a new call to the same function
creates a new scope, i.e., the parameter is still associated with the
call stack rather than with the function definition. It differs from ksh
‘<code>typeset -S</code>’ because the syntax used to define the function has no
bearing on whether the parameter scope is respected.</p>
<hr />
<p><span id="The-zsh_002fregex-Module"></span>
<span id="The-zsh_002fregex-Module-1"></span></p>
<h2 id="2223-the-zshregex-module"><a class="header" href="#2223-the-zshregex-module">22.23 The zsh/regex Module</a></h2>
<p><span id="index-regular-expressions"></span>
<span id="index-regex"></span></p>
<p>The <code>zsh/regex</code> module makes available the following test condition:</p>
<p><span id="index-regex_002dmatch"></span></p>
<p><code>expr</code> <code>-regex-match</code> <code>regex</code></p>
<p>Matches a string against a POSIX extended regular expression. On
successful match, matched portion of the string will normally be placed
in the <code>MATCH</code> variable. If there are any capturing parentheses within
the regex, then the <code>match</code> array variable will contain those. If the
match is not successful, then the variables will not be altered.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">[[ alphabetical -regex-match ^a([^a]+)a([^a]+)a ]] &amp;&amp;
print -l $MATCH X $match
</code></pre>
</div>
<p>If the option <code>REMATCH_PCRE</code> is not set, then the <code>=~</code> operator will
automatically load this module as needed and will invoke the
<code>-regex-match</code> operator.</p>
<p>If <code>BASH_REMATCH</code> is set, then the array <code>BASH_REMATCH</code> will be set
instead of <code>MATCH</code> and <code>match</code>.</p>
<hr />
<p><span id="The-zsh_002fsched-Module"></span>
<span id="The-zsh_002fsched-Module-1"></span></p>
<h2 id="2224-the-zshsched-module"><a class="header" href="#2224-the-zshsched-module">22.24 The zsh/sched Module</a></h2>
<p>The <code>zsh/sched</code> module makes available one builtin command and one
parameter.</p>
<p><span id="index-sched"></span> <span id="index-timed-execution"></span>
<span id="index-execution_002c-timed"></span></p>
<p><code>sched</code> [<code>-o</code>] [<code>+</code>]<code>hh``:``mm</code>[<code>:``ss</code>] <code>command</code> ...</p>
<p><code>sched</code> [<code>-o</code>] [<code>+</code>]<code>seconds</code> <code>command</code> ...</p>
<p><code>sched</code> [ <code>-``item</code> ]</p>
<p>Make an entry in the scheduled list of commands to execute. The time may
be specified in either absolute or relative time, and either as hours,
minutes and (optionally) seconds separated by a colon, or seconds alone.
An absolute number of seconds indicates the time since the epoch
(1970/01/01 00:00); this is useful in combination with the features in
the <code>zsh/datetime</code> module, see <a href="Zsh-Modules.html#The-zsh_002fdatetime-Module">The zsh/datetime
Module</a>.</p>
<p>With no arguments, prints the list of scheduled commands. If the
scheduled command has the <code>-o</code> flag set, this is shown at the start of
the command.</p>
<p>With the argument ‘<code>-``item</code>’, removes the given item from the list. The
numbering of the list is continuous and entries are in time order, so
the numbering can change when entries are added or deleted.</p>
<p>Commands are executed either immediately before a prompt, or while the
shell’s line editor is waiting for input. In the latter case it is
useful to be able to produce output that does not interfere with the
line being edited. Providing the option <code>-o</code> causes the shell to clear
the command line before the event and redraw it afterwards. This should
be used with any scheduled event that produces visible output to the
terminal; it is not needed, for example, with output that updates a
terminal emulator’s title bar.</p>
<p>To effect changes to the editor buffer when an event executes, use the
‘<code>zle</code>’ command with no arguments to test whether the editor is
active, and if it is, then use ‘<code> zle ``widget</code>’ to access the editor
via the named <code>widget</code>.</p>
<p>The <code>sched</code> builtin is not made available by default when the shell
starts in a mode emulating another shell. It can be made available with
the command ‘<code>zmodload -F zsh/sched b:sched</code>’.</p>
<p><span id="index-zsh_005fscheduled_005fevents"></span></p>
<p><code>zsh_scheduled_events</code></p>
<p>A readonly array corresponding to the events scheduled by the <code>sched</code>
builtin. The indices of the array correspond to the numbers shown when
<code>sched</code> is run with no arguments (provided that the <code>KSH_ARRAYS</code> option
is not set). The value of the array consists of the scheduled time in
seconds since the epoch (see <a href="Zsh-Modules.html#The-zsh_002fdatetime-Module">The zsh/datetime
Module</a> for facilities for using this
number), followed by a colon, followed by any options (which may be
empty but will be preceded by a ‘<code>-</code>’ otherwise), followed by a colon,
followed by the command to be executed.</p>
<p>The <code>sched</code> builtin should be used for manipulating the events. Note
that this will have an immediate effect on the contents of the array, so
that indices may become invalid.</p>
<hr />
<p><span id="The-zsh_002fnet_002fsocket-Module"></span>
<span id="The-zsh_002fnet_002fsocket-Module-1"></span></p>
<h2 id="2225-the-zshnetsocket-module"><a class="header" href="#2225-the-zshnetsocket-module">22.25 The zsh/net/socket Module</a></h2>
<p>The <code>zsh/net/socket</code> module makes available one builtin command:</p>
<p><span id="index-zsocket"></span> <span id="index-sockets"></span>
<span id="index-sockets_002c-Unix-domain"></span></p>
<p><code>zsocket</code> [ <code>-altv</code> ] [ <code>-d</code> <code>fd</code> ] [ <code>args</code> ]</p>
<p><code>zsocket</code> is implemented as a builtin to allow full use of shell command
line editing, file I/O, and job control mechanisms.</p>
<hr />
<p><span id="Outbound-Connections-1"></span></p>
<h3 id="22251-outbound-connections"><a class="header" href="#22251-outbound-connections">22.25.1 Outbound Connections</a></h3>
<p><span id="index-sockets_002c-outbound-Unix-domain"></span></p>
<ul>
<li>
<p><code>zsocket</code> [ <code>-v</code> ] [ <code>-d</code> <code>fd</code> ] <code>filename</code><br />
Open a new Unix domain connection to <code>filename</code>. The shell parameter
<code>REPLY</code> will be set to the file descriptor associated with that
connection. Currently, only stream connections are supported.</p>
<p>If <code>-d</code> is specified, its argument will be taken as the target file
descriptor for the connection.</p>
<p>In order to elicit more verbose output, use <code>-v</code>.</p>
<p>File descriptors can be closed with normal shell syntax when no
longer needed, for example:</p>
<div class="example">
<pre><code class="language-example">exec {REPLY}&gt;&amp;-
</code></pre>
</div>
</li>
</ul>
<hr />
<p><span id="Inbound-Connections"></span></p>
<h3 id="22252-inbound-connections"><a class="header" href="#22252-inbound-connections">22.25.2 Inbound Connections</a></h3>
<p><span id="index-sockets_002c-inbound-Unix-domain"></span></p>
<ul>
<li>
<p><code>zsocket</code> <code>-l</code> [ <code>-v</code> ] [ <code>-d</code> <code>fd</code> ] <code>filename</code><br />
<code>zsocket -l</code> will open a socket listening on <code>filename</code>. The shell
parameter <code>REPLY</code> will be set to the file descriptor associated with
that listener. The file descriptor remains open in subshells</p>
<p>If <code>-d</code> is specified, its argument will be taken as the target file
descriptor for the connection.</p>
<p>In order to elicit more verbose output, use <code>-v</code>.</p>
</li>
<li>
<p><code>zsocket</code> <code>-a</code> [ <code>-tv</code> ] [ <code>-d</code> <code>targetfd</code> ] <code>listenfd</code><br />
<code>zsocket -a</code> will accept an incoming connection to the socket
associated with <code>listenfd</code>. The shell parameter <code>REPLY</code> will be set
to the file descriptor associated with the inbound connection. The
file descriptor remains open in subshells</p>
<p>If <code>-d</code> is specified, its argument will be taken as the target file
descriptor for the connection.</p>
<p>If <code>-t</code> is specified, <code>zsocket</code> will return if no incoming
connection is pending. Otherwise it will wait for one.</p>
<p>In order to elicit more verbose output, use <code>-v</code>.</p>
</li>
</ul>
<hr />
<p><span id="The-zsh_002fstat-Module"></span>
<span id="The-zsh_002fstat-Module-1"></span></p>
<h2 id="2226-the-zshstat-module"><a class="header" href="#2226-the-zshstat-module">22.26 The zsh/stat Module</a></h2>
<p>The <code>zsh/stat</code> module makes available one builtin command under two
possible names:</p>
<p><span id="index-zstat"></span> <span id="index-stat"></span>
<span id="index-files_002c-listing"></span>
<span id="index-files_002c-examining"></span></p>
<p><code>zstat </code>[ <code>-gnNolLtTrs</code> ] [ <code>-f</code> <code>fd</code> ] [ <code>-H</code> <code>hash</code> ] [ <code>-A</code>
<code>array</code> ] [ <code>-F</code> <code>fmt</code> ]</p>
<p><code>      </code>[ <code>+``element</code> ] [ <code>file</code> ... ]</p>
<p><code>stat</code> <code>...</code></p>
<p>The command acts as a front end to the <code>stat</code> system call (see man page
stat(2)). The same command is provided with two names; as the name
<code>stat</code> is often used by an external command it is recommended that only
the <code>zstat</code> form of the command is used. This can be arranged by loading
the module with the command ‘<code>zmodload -F zsh/stat b:zstat</code>’.</p>
<p>If the <code>stat</code> call fails, the appropriate system error message printed
and status 1 is returned. The fields of <code>struct stat</code> give information
about the files provided as arguments to the command. In addition to
those available from the <code>stat</code> call, an extra element ‘<code>link</code>’ is
provided. These elements are:</p>
<ul>
<li>
<p><code>device</code><br />
The number of the device on which the file resides.</p>
</li>
<li>
<p><code>inode</code><br />
The unique number of the file on this device (‘<em>inode</em>’ number).</p>
</li>
<li>
<p><code>mode</code><br />
The mode of the file; that is, the file’s type and access
permissions. With the <code>-s</code> option, this will be returned as a string
corresponding to the first column in the display of the <code>ls -l</code>
command.</p>
</li>
<li>
<p><code>nlink</code><br />
The number of hard links to the file.</p>
</li>
<li>
<p><code>uid</code><br />
The user ID of the owner of the file. With the <code>-s</code> option, this is
displayed as a user name.</p>
</li>
<li>
<p><code>gid</code><br />
The group ID of the file. With the <code>-s</code> option, this is displayed as
a group name.</p>
</li>
<li>
<p><code>rdev</code><br />
The raw device number. This is only useful for special devices.</p>
</li>
<li>
<p><code>size</code><br />
The size of the file in bytes.</p>
</li>
<li>
<p><code>atime</code><br />
<code>mtime</code><br />
<code>ctime</code><br />
The last access, modification and inode change times of the file,
respectively, as the number of seconds since midnight GMT on 1st
January, 1970. With the <code>-s</code> option, these are printed as strings
for the local time zone; the format can be altered with the <code>-F</code>
option, and with the <code>-g</code> option the times are in GMT.</p>
</li>
<li>
<p><code>blksize</code><br />
The number of bytes in one allocation block on the device on which
the file resides.</p>
</li>
<li>
<p><code>block</code><br />
The number of disk blocks used by the file.</p>
</li>
<li>
<p><code>link</code><br />
If the file is a link and the <code>-L</code> option is in effect, this
contains the name of the file linked to, otherwise it is empty. Note
that if this element is selected (‘‘<code>zstat +link</code>’’) then the <code>-L</code>
option is automatically used.</p>
</li>
</ul>
<p>A particular element may be selected by including its name preceded by a
‘<code>+</code>’ in the option list; only one element is allowed. The element may
be shortened to any unique set of leading characters. Otherwise, all
elements will be shown for all files.</p>
<p>Options:</p>
<ul>
<li>
<p><code>-A</code> <code>array</code><br />
Instead of displaying the results on standard output, assign them to
an <code>array</code>, one <code>struct stat</code> element per array element for each
file in order. In this case neither the name of the element nor the
name of the files appears in <code>array</code> unless the <code>-t</code> or <code>-n</code> options
were given, respectively. If <code>-t</code> is given, the element name appears
as a prefix to the appropriate array element; if <code>-n</code> is given, the
file name appears as a separate array element preceding all the
others. Other formatting options are respected.</p>
</li>
<li>
<p><code>-H</code> <code>hash</code><br />
Similar to <code>-A</code>, but instead assign the values to <code>hash</code>. The keys
are the elements listed above. If the <code>-n</code> option is provided then
the name of the file is included in the hash with key <code>name</code>.</p>
</li>
<li>
<p><code>-f</code> <code>fd</code><br />
Use the file on file descriptor <code>fd</code> instead of named files; no list
of file names is allowed in this case.</p>
</li>
<li>
<p><code>-F</code> <code>fmt</code><br />
Supplies a <code>strftime</code> (see man page strftime(3)) string for the
formatting of the time elements. The format string supports all of
the zsh extensions described in <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>. The <code>-s</code> option
is implied.</p>
</li>
<li>
<p><code>-g</code><br />
Show the time elements in the GMT time zone. The <code>-s</code> option is
implied.</p>
</li>
<li>
<p><code>-l</code><br />
List the names of the type elements (to standard output or an array
as appropriate) and return immediately; arguments, and options other
than <code>-A</code>, are ignored.</p>
</li>
<li>
<p><code>-L</code><br />
Perform an <code>lstat</code> (see man page lstat(2)) rather than a <code>stat</code>
system call. In this case, if the file is a link, information about
the link itself rather than the target file is returned. This option
is required to make the <code>link</code> element useful. It’s important to
note that this is the exact opposite from man page ls(1), etc.</p>
</li>
<li>
<p><code>-n</code><br />
Always show the names of files. Usually these are only shown when
output is to standard output and there is more than one file in the
list.</p>
</li>
<li>
<p><code>-N</code><br />
Never show the names of files.</p>
</li>
<li>
<p><code>-o</code><br />
If a raw file mode is printed, show it in octal, which is more
useful for human consumption than the default of decimal. A leading
zero will be printed in this case. Note that this does not affect
whether a raw or formatted file mode is shown, which is controlled
by the <code>-r</code> and <code>-s</code> options, nor whether a mode is shown at all.</p>
</li>
<li>
<p><code>-r</code><br />
Print raw data (the default format) alongside string data (the <code>-s</code>
format); the string data appears in parentheses after the raw data.</p>
</li>
<li>
<p><code>-s</code><br />
Print <code>mode</code>, <code>uid</code>, <code>gid</code> and the three time elements as strings
instead of numbers. In each case the format is like that of <code>ls -l</code>.</p>
</li>
<li>
<p><code>-t</code><br />
Always show the type names for the elements of <code>struct stat</code>.
Usually these are only shown when output is to standard output and
no individual element has been selected.</p>
</li>
<li>
<p><code>-T</code><br />
Never show the type names of the <code>struct stat</code> elements.</p>
</li>
</ul>
<hr />
<p><span id="The-zsh_002fsystem-Module"></span>
<span id="The-zsh_002fsystem-Module-1"></span></p>
<h2 id="2227-the-zshsystem-module"><a class="header" href="#2227-the-zshsystem-module">22.27 The zsh/system Module</a></h2>
<p>The <code>zsh/system</code> module makes available various builtin commands and
parameters.</p>
<hr />
<p><span id="Builtins"></span></p>
<h3 id="22271-builtins"><a class="header" href="#22271-builtins">22.27.1 Builtins</a></h3>
<p><span id="index-syserror"></span></p>
<p><code>syserror</code> [ <code>-e</code> <code>errvar</code> ] [ <code>-p</code> <code>prefix</code> ] [ <code>errno</code> |
<code>errname</code> ]</p>
<p>This command prints out the error message associated with <code>errno</code>, a
system error number, followed by a newline to standard error.</p>
<p>Instead of the error number, a name <code>errname</code>, for example <code>ENOENT</code>, may
be used. The set of names is the same as the contents of the array
<code>errnos</code>, see below.</p>
<p>If the string <code>prefix</code> is given, it is printed in front of the error
message, with no intervening space.</p>
<p>If <code>errvar</code> is supplied, the entire message, without a newline, is
assigned to the parameter names <code>errvar</code> and nothing is output.</p>
<p>A return status of 0 indicates the message was successfully printed
(although it may not be useful if the error number was out of the
system’s range), a return status of 1 indicates an error in the
parameters, and a return status of 2 indicates the error name was not
recognised (no message is printed for this).</p>
<p><span id="index-sysopen"></span></p>
<p><code>sysopen</code> [ <code>-arw</code> ] [ <code>-m</code> <code>permissions</code> ] [ <code>-o</code> <code>options</code> ]</p>
<p><code>        ``-u</code> <code>fd</code> <code>file</code></p>
<p>This command opens a file. The <code>-r</code>, <code>-w</code> and <code>-a</code> flags indicate
whether the file should be opened for reading, writing and appending,
respectively. The <code>-m</code> option allows the initial permissions to use when
creating a file to be specified in octal form. The file descriptor is
specified with <code>-u</code>. Either an explicit file descriptor in the range 0
to 9 can be specified or a variable name can be given to which the file
descriptor number will be assigned.</p>
<p>The <code>-o</code> option allows various system specific options to be specified
as a comma-separated list. The following is a list of possible options.
Note that, depending on the system, some may not be available.</p>
<ul>
<li>
<p><code>cloexec</code><br />
mark file to be closed when other programs are executed (else the
file descriptor remains open in subshells and forked external</p>
</li>
<li>
<p><code>create</code><br />
<code>creat</code><br />
create file if it does not exist</p>
</li>
<li>
<p><code>excl</code><br />
create file, error if it already exists</p>
</li>
<li>
<p><code>noatime</code><br />
suppress updating of the file atime</p>
</li>
<li>
<p><code>nofollow</code><br />
fail if <code>file</code> is a symbolic link</p>
</li>
<li>
<p><code>sync</code><br />
request that writes wait until data has been physically written</p>
</li>
<li>
<p><code>truncate</code><br />
<code>trunc</code><br />
truncate file to size 0</p>
</li>
</ul>
<p>To close the file, use one of the following:</p>
<div class="example">
<pre><code class="language-example">exec {fd}&lt;&amp;-
exec {fd}&gt;&amp;-
</code></pre>
</div>
<p><span id="index-sysread"></span></p>
<p><code>sysread </code>[ <code>-c</code> <code>countvar</code> ] [ <code>-i</code> <code>infd</code> ] [ <code>-o</code> <code>outfd</code> ]</p>
<p><code>        </code>[ <code>-s</code> <code>bufsize</code> ] [ <code>-t</code> <code>timeout</code> ] [ <code>param</code> ]</p>
<p>Perform a single system read from file descriptor <code>infd</code>, or zero if
that is not given. The result of the read is stored in <code>param</code> or
<code>REPLY</code> if that is not given. If <code>countvar</code> is given, the number of
bytes read is assigned to the parameter named by <code>countvar</code>.</p>
<p>The maximum number of bytes read is <code>bufsize</code> or 8192 if that is not
given, however the command returns as soon as any number of bytes was
successfully read.</p>
<p>If <code>timeout</code> is given, it specifies a timeout in seconds, which may be
zero to poll the file descriptor. This is handled by the <code>poll</code> system
call if available, otherwise the <code>select</code> system call if available.</p>
<p>If <code>outfd</code> is given, an attempt is made to write all the bytes just read
to the file descriptor <code>outfd</code>. If this fails, because of a system error
other than <code>EINTR</code> or because of an internal zsh error during an
interrupt, the bytes read but not written are stored in the parameter
named by <code>param</code> if supplied (no default is used in this case), and the
number of bytes read but not written is stored in the parameter named by
<code>countvar</code> if that is supplied. If it was successful, <code>countvar</code>
contains the full number of bytes transferred, as usual, and <code>param</code> is
not set.</p>
<p>The error <code>EINTR</code> (interrupted system call) is handled internally so
that shell interrupts are transparent to the caller. Any other error
causes a return.</p>
<p>The possible return statuses are</p>
<ul>
<li>
<p>0<br />
At least one byte of data was successfully read and, if appropriate,
written.</p>
</li>
<li>
<p>1<br />
There was an error in the parameters to the command. This is the
only error for which a message is printed to standard error.</p>
</li>
<li>
<p>2<br />
There was an error on the read, or on polling the input file
descriptor for a timeout. The parameter <code>ERRNO</code> gives the error.</p>
</li>
<li>
<p>3<br />
Data were successfully read, but there was an error writing them to
<code>outfd</code>. The parameter <code>ERRNO</code> gives the error.</p>
</li>
<li>
<p>4<br />
The attempt to read timed out. Note this does not set <code>ERRNO</code> as
this is not a system error.</p>
</li>
<li>
<p>5<br />
No system error occurred, but zero bytes were read. This usually
indicates end of file. The parameters are set according to the usual
rules; no write to <code>outfd</code> is attempted.</p>
</li>
</ul>
<p><code>sysseek</code> [ <code>-u</code> <code>fd</code> ] [ <code>-w</code> <code>start</code>|<code>end</code>|<code>current</code> ] <code>offset</code></p>
<p>The current file position at which future reads and writes will take
place is adjusted to the specified byte offset. The <code>offset</code> is
evaluated as a math expression. The <code>-u</code> option allows the file
descriptor to be specified. By default the offset is specified relative
to the start or the file but, with the <code>-w</code> option, it is possible to
specify that the offset should be relative to the current position or
the end of the file.</p>
<p><code>syswrite</code> [ <code>-c</code> <code>countvar</code> ] [ <code>-o</code> <code>outfd</code> ] <code>data</code></p>
<p>The data (a single string of bytes) are written to the file descriptor
<code>outfd</code>, or 1 if that is not given, using the <code>write</code> system call.
Multiple write operations may be used if the first does not write all
the data.</p>
<p>If <code>countvar</code> is given, the number of byte written is stored in the
parameter named by <code>countvar</code>; this may not be the full length of <code>data</code>
if an error occurred.</p>
<p>The error <code>EINTR</code> (interrupted system call) is handled internally by
retrying; otherwise an error causes the command to return. For example,
if the file descriptor is set to non-blocking output, an error <code>EAGAIN</code>
(on some systems, <code>EWOULDBLOCK</code>) may result in the command returning
early.</p>
<p>The return status may be 0 for success, 1 for an error in the parameters
to the command, or 2 for an error on the write; no error message is
printed in the last case, but the parameter <code>ERRNO</code> will reflect the
error that occurred.</p>
<p><code>zsystem flock</code> [ <code>-t</code> <code>timeout</code> ] [ <code>-f</code> <code>var</code> ] [<code>-er</code>] <code>file</code></p>
<p><code>zsystem flock -u</code> <code>fd_expr</code></p>
<p>The builtin <code>zsystem</code>’s subcommand <code>flock</code> performs advisory file
locking (via the man page fcntl(2) system call) over the entire contents
of the given file. This form of locking requires the processes accessing
the file to cooperate; its most obvious use is between two instances of
the shell itself.</p>
<p>In the first form the named <code>file</code>, which must already exist, is locked
by opening a file descriptor to the file and applying a lock to the file
descriptor. The lock terminates when the shell process that created the
lock exits; it is therefore often convenient to create file locks within
subshells, since the lock is automatically released when the subshell
exits. Note that use of the <code>print</code> builtin with the <code>-u</code> option will,
as a side effect, release the lock, as will redirection to the file in
the shell holding the lock. To work around this use a subshell, e.g.
‘<code> (print message) &gt;&gt; ``file</code>’. Status 0 is returned if the lock
succeeds, else status 1.</p>
<p>In the second form the file descriptor given by the arithmetic
expression <code>fd_expr</code> is closed, releasing a lock. The file descriptor
can be queried by using the ‘<code>-f</code> <code>var</code>’ form during the lock; on a
successful lock, the shell variable <code>var</code> is set to the file descriptor
used for locking. The lock will be released if the file descriptor is
closed by any other means, for example using ‘<code>exec {``var``}&gt;&amp;-</code>’;
however, the form described here performs a safety check that the file
descriptor is in use for file locking.</p>
<p>By default the shell waits indefinitely for the lock to succeed. The
option <code>-t</code> <code>timeout</code> specifies a timeout for the lock in seconds;
currently this must be an integer. The shell will attempt to lock the
file once a second during this period. If the attempt times out, status
2 is returned.</p>
<p>If the option <code>-e</code> is given, the file descriptor for the lock is
preserved when the shell uses <code>exec</code> to start a new process; otherwise
it is closed at that point and the lock released.</p>
<p>If the option <code>-r</code> is given, the lock is only for reading, otherwise it
is for reading and writing. The file descriptor is opened accordingly.</p>
<p><code>zsystem supports</code> <code>subcommand</code></p>
<p>The builtin <code>zsystem</code>’s subcommand <code>supports</code> tests whether a given
subcommand is supported. It returns status 0 if so, else status 1. It
operates silently unless there was a syntax error (i.e. the wrong number
of arguments), in which case status 255 is returned. Status 1 can
indicate one of two things: <code>subcommand</code> is known but not supported by
the current operating system, or <code>subcommand</code> is not known (possibly
because this is an older version of the shell before it was
implemented).</p>
<hr />
<p><span id="Math-Functions"></span></p>
<h3 id="22272-math-functions"><a class="header" href="#22272-math-functions">22.27.2 Math Functions</a></h3>
<ul>
<li><code>systell(fd)</code><br />
The systell math function returns the current file position for the
file descriptor passed as an argument.</li>
</ul>
<hr />
<p><span id="Parameters-3"></span></p>
<h3 id="22273-parameters"><a class="header" href="#22273-parameters">22.27.3 Parameters</a></h3>
<p><span id="index-errnos"></span></p>
<p><code>errnos</code></p>
<p>A readonly array of the names of errors defined on the system. These are
typically macros defined in C by including the system header file
<code>errno.h</code>. The index of each name (assuming the option <code>KSH_ARRAYS</code> is
unset) corresponds to the error number. Error numbers <code>num</code> before the
last known error which have no name are given the name <code>E``num</code> in the
array.</p>
<p>Note that aliases for errors are not handled; only the canonical name is
used.</p>
<p><span id="index-sysparams"></span></p>
<p><code>sysparams</code></p>
<p>A readonly associative array. The keys are:</p>
<ul>
<li>
<p><code>pid</code><br />
<span id="index-pid_002c-sysparams"></span></p>
<p>Returns the process ID of the current process, even in subshells.
Compare <code>$$</code>, which returns the process ID of the main shell
process.</p>
</li>
<li>
<p><code>ppid</code><br />
<span id="index-ppid_002c-sysparams"></span></p>
<p>Returns the process ID of the parent of the current process, even in
subshells. Compare <code>$PPID</code>, which returns the process ID of the
parent of the main shell process.</p>
</li>
<li>
<p><code>procsubstpid</code><br />
Returns the process ID of the last process started for process
substitution, i.e. the <code>&lt;(``...``)</code> and <code>&gt;(``...``)</code> expansions.</p>
</li>
</ul>
<hr />
<p><span id="The-zsh_002fnet_002ftcp-Module"></span>
<span id="The-zsh_002fnet_002ftcp-Module-1"></span></p>
<h2 id="2228-the-zshnettcp-module"><a class="header" href="#2228-the-zshnettcp-module">22.28 The zsh/net/tcp Module</a></h2>
<p>The <code>zsh/net/tcp</code> module makes available one builtin command:</p>
<p><span id="index-ztcp"></span> <span id="index-TCP"></span>
<span id="index-sockets_002c-TCP"></span></p>
<p><code>ztcp</code> [ <code>-acflLtv</code> ] [ <code>-d</code> <code>fd</code> ] [ <code>args</code> ]</p>
<p><code>ztcp</code> is implemented as a builtin to allow full use of shell command
line editing, file I/O, and job control mechanisms.</p>
<p>If <code>ztcp</code> is run with no options, it will output</p>
<p>If it is run with only the option <code>-L</code>, it will output the contents of
is ignored if given with a command to open or close a session. The
output consists of a set of lines, one per session, each containing the
following elements separated by spaces:</p>
<ul>
<li>
<p>File descriptor<br />
The file descriptor in use for the connection. For normal inbound
(<code>I</code>) and outbound (<code>O</code>) connections this may be read and written by
the usual shell mechanisms. However, it should only be close with
‘<code>ztcp -c</code>’.</p>
</li>
<li>
<p>Connection type<br />
A letter indicating how the session was created:</p>
<ul>
<li>
<p><code>Z</code><br />
A session created with the <code>zftp</code> command.</p>
</li>
<li>
<p><code>L</code><br />
A connection opened for listening with ‘<code>ztcp -l</code>’.</p>
</li>
<li>
<p><code>I</code><br />
An inbound connection accepted with ‘<code>ztcp -a</code>’.</p>
</li>
<li>
<p><code>O</code><br />
An outbound connection created with ‘<code>ztcp</code> <code>host</code> <code>...</code>’.</p>
</li>
</ul>
</li>
<li>
<p>The local host<br />
This is usually set to an all-zero IP address as the address of the
localhost is irrelevant.</p>
</li>
<li>
<p>The local port<br />
This is likely to be zero unless the connection is for listening.</p>
</li>
<li>
<p>The remote host<br />
This is the fully qualified domain name of the peer, if available,
else an IP address. It is an all-zero IP address for a session
opened for listening.</p>
</li>
<li>
<p>The remote port<br />
This is zero for a connection opened for listening.</p>
</li>
</ul>
<hr />
<p><span id="Outbound-Connections"></span></p>
<h3 id="22281-outbound-connections"><a class="header" href="#22281-outbound-connections">22.28.1 Outbound Connections</a></h3>
<p><span id="index-sockets_002c-outbound-TCP"></span></p>
<ul>
<li>
<p><code>ztcp</code> [ <code>-v</code> ] [ <code>-d</code> <code>fd</code> ] <code>host</code> [ <code>port</code> ]<br />
Open a new TCP connection to <code>host</code>. If the <code>port</code> is omitted, it
will default to port 23. The connection will <code>REPLY</code> will be set to
the file descriptor associated with that connection.</p>
<p>If <code>-d</code> is specified, its argument will be taken as the target file
descriptor for the connection.</p>
<p>In order to elicit more verbose output, use <code>-v</code>.</p>
</li>
</ul>
<hr />
<p><span id="Inbound-Connections-1"></span></p>
<h3 id="22282-inbound-connections"><a class="header" href="#22282-inbound-connections">22.28.2 Inbound Connections</a></h3>
<p><span id="index-sockets_002c-inbound-TCP"></span></p>
<ul>
<li>
<p><code>ztcp</code> <code>-l</code> [ <code>-v</code> ] [ <code>-d</code> <code>fd</code> ] <code>port</code><br />
<code>ztcp -l</code> will open a socket listening on TCP <code>port</code>. The socket
will be added to the will be set to the file descriptor associated
with that listener.</p>
<p>If <code>-d</code> is specified, its argument will be taken as the target file
descriptor for the connection.</p>
<p>In order to elicit more verbose output, use <code>-v</code>.</p>
</li>
<li>
<p><code>ztcp</code> <code>-a</code> [ <code>-tv</code> ] [ <code>-d</code> <code>targetfd</code> ] <code>listenfd</code><br />
<code>ztcp -a</code> will accept an incoming connection to the port associated
with <code>listenfd</code>. The connection will be added to the session be set
to the file descriptor associated with the inbound connection.</p>
<p>If <code>-d</code> is specified, its argument will be taken as the target file
descriptor for the connection.</p>
<p>If <code>-t</code> is specified, <code>ztcp</code> will return if no incoming connection
is pending. Otherwise it will wait for one.</p>
<p>In order to elicit more verbose output, use <code>-v</code>.</p>
</li>
</ul>
<hr />
<p><span id="Closing-Connections"></span></p>
<h3 id="22283-closing-connections"><a class="header" href="#22283-closing-connections">22.28.3 Closing Connections</a></h3>
<p><span id="index-sockets_002c-closing-TCP"></span></p>
<ul>
<li>
<p><code>ztcp</code> <code>-cf</code> [ <code>-v</code> ] [ <code>fd</code> ]<br />
<code>ztcp</code> <code>-c</code> [ <code>-v</code> ] [ <code>fd</code> ]<br />
<code>ztcp -c</code> will close the socket associated with <code>fd</code>. The socket
will be removed from the</p>
<p>Normally, sockets registered by zftp (see <a href="Zsh-Modules.html#The-zsh_002fzftp-Module">The zsh/zftp
Module</a> ) cannot be closed this way. In
order to force such a socket closed, use <code>-f</code>.</p>
<p>In order to elicit more verbose output, use <code>-v</code>.</p>
</li>
</ul>
<hr />
<p><span id="Example-1"></span></p>
<h3 id="22284-example"><a class="header" href="#22284-example">22.28.4 Example</a></h3>
<p><span id="index-TCP_002c-example"></span></p>
<p>Here is how to create a TCP connection between two instances of zsh. We
need to pick an unassigned port; here we use the randomly chosen 5123.</p>
<p>On <code>host1</code>,</p>
<div class="example">
<pre><code class="language-example">zmodload zsh/net/tcp
ztcp -l 5123
listenfd=$REPLY
ztcp -a $listenfd
fd=$REPLY
</code></pre>
</div>
<p>The second from last command blocks until there is an incoming
connection.</p>
<p>Now create a connection from <code>host2</code> (which may, of course, be the same
machine):</p>
<div class="example">
<pre><code class="language-example">zmodload zsh/net/tcp
ztcp host1 5123
fd=$REPLY
</code></pre>
</div>
<p>Now on each host, <code>$fd</code> contains a file descriptor for talking to the
other. For example, on <code>host1</code>:</p>
<div class="example">
<pre><code class="language-example">print This is a message &gt;&amp;$fd
</code></pre>
</div>
<p>and on <code>host2</code>:</p>
<div class="example">
<pre><code class="language-example">read -r line &lt;&amp;$fd; print -r - $line
</code></pre>
</div>
<p>prints ‘<code>This is a message</code>’.</p>
<p>To tidy up, on <code>host1</code>:</p>
<div class="example">
<pre><code class="language-example">ztcp -c $listenfd
ztcp -c $fd
</code></pre>
</div>
<p>and on <code>host2</code></p>
<div class="example">
<pre><code class="language-example">ztcp -c $fd
</code></pre>
</div>
<hr />
<p><span id="The-zsh_002ftermcap-Module"></span>
<span id="The-zsh_002ftermcap-Module-1"></span></p>
<h2 id="2229-the-zshtermcap-module"><a class="header" href="#2229-the-zshtermcap-module">22.29 The zsh/termcap Module</a></h2>
<p>The <code>zsh/termcap</code> module makes available one builtin command:</p>
<p><span id="index-echotc"></span>
<span id="index-termcap-value_002c-printing"></span></p>
<p><code>echotc</code> <code>cap</code> [ <code>arg</code> ... ]</p>
<p>Output the termcap value corresponding to the capability <code>cap</code>, with
optional arguments.</p>
<p>The <code>zsh/termcap</code> module makes available one parameter:</p>
<p><span id="index-termcap"></span></p>
<p><code>termcap</code></p>
<p>An associative array that maps termcap capability codes to their values.</p>
<hr />
<p><span id="The-zsh_002fterminfo-Module"></span>
<span id="The-zsh_002fterminfo-Module-1"></span></p>
<h2 id="2230-the-zshterminfo-module"><a class="header" href="#2230-the-zshterminfo-module">22.30 The zsh/terminfo Module</a></h2>
<p>The <code>zsh/terminfo</code> module makes available one builtin command:</p>
<p><span id="index-echoti"></span>
<span id="index-terminfo-value_002c-printing"></span></p>
<p><code>echoti</code> <code>cap</code> [ <code>arg</code> ]</p>
<p>Output the terminfo value corresponding to the capability <code>cap</code>,
instantiated with <code>arg</code> if applicable.</p>
<p>The <code>zsh/terminfo</code> module makes available one parameter:</p>
<p><span id="index-terminfo"></span></p>
<p><code>terminfo</code></p>
<p>An associative array that maps terminfo capability names to their
values.</p>
<hr />
<p><span id="The-zsh_002fzftp-Module"></span>
<span id="The-zsh_002fzftp-Module-1"></span></p>
<h2 id="2231-the-zshzftp-module"><a class="header" href="#2231-the-zshzftp-module">22.31 The zsh/zftp Module</a></h2>
<p>The <code>zsh/zftp</code> module makes available one builtin command:</p>
<p><span id="index-zftp"></span> <span id="index-FTP"></span>
<span id="index-files_002c-transferring"></span></p>
<p><code>zftp</code> <code>subcommand</code> [ <code>args</code> ]</p>
<p>The <code>zsh/zftp</code> module is a client for FTP (file transfer protocol). It
is implemented as a builtin to allow full use of shell command line
editing, file I/O, and job control mechanisms. Often, users will access
it via shell functions providing a more powerful interface; a set is
provided with the <code>zsh</code> distribution and is described in <a href="Zftp-Function-System.html#Zftp-Function-System">Zftp Function
System</a>. However, the
<code>zftp</code> command is entirely usable in its own right.</p>
<p>All commands consist of the command name <code>zftp</code> followed by the name of
a subcommand. These are listed below. The return status of each
subcommand is supposed to reflect the success or failure of the remote
operation. See a description of the variable <code>ZFTP_VERBOSE</code> for more
information on how responses from the server may be printed.</p>
<hr />
<p><span id="Subcommands"></span></p>
<h3 id="22311-subcommands"><a class="header" href="#22311-subcommands">22.31.1 Subcommands</a></h3>
<p><span id="index-zftp_002c-subcommands"></span></p>
<p><span id="index-FTP_002c-starting-a-session"></span></p>
<p><code>open</code> <code>host</code>[<code>:``port</code>] [ <code>user</code> [ <code>password</code> [ <code>account</code> ] ] ]</p>
<p>Open a new FTP session to <code>host</code>, which may be the name of a TCP/IP
connected host or an IP number in the standard dot notation. If the
argument is in the form <code>host``:``port</code>, open a connection to TCP port
<code>port</code> instead of the standard FTP port 21. This may be the name of a
TCP service or a number: see the description of <code>ZFTP_PORT</code> below for
more information.</p>
<p>If IPv6 addresses in colon format are used, the <code>host</code> should be
surrounded by quoted square brackets to distinguish it from the <code>port</code>,
for example <code>’[fe80::203:baff:fe02:8b56]’</code>. For consistency this is
allowed with all forms of <code>host</code>.</p>
<p>Remaining arguments are passed to the <code>login</code> subcommand. Note that if
no arguments beyond <code>host</code> are supplied, <code>open</code> will <em>not</em> automatically
call <code>login</code>. If no arguments at all are supplied, <code>open</code> will use the
parameters set by the <code>params</code> subcommand.</p>
<p>After a successful open, the shell variables <code>ZFTP_HOST</code>, <code>ZFTP_PORT</code>,
<code>ZFTP_IP</code> and <code>ZFTP_SYSTEM</code> are available; see ‘Variables’ below.</p>
<p><code>login</code> [ <code>name</code> [ <code>password</code> [ <code>account</code> ] ] ]</p>
<p><code>user</code> [ <code>name</code> [ <code>password</code> [ <code>account</code> ] ] ]</p>
<p>Login the user <code>name</code> with parameters <code>password</code> and <code>account</code>. Any of
the parameters can be omitted, and will be read from standard input if
needed (<code>name</code> is always needed). If standard input is a terminal, a
prompt for each one will be printed on standard error and <code>password</code>
will not be echoed. If any of the parameters are not used, a warning
message is printed.</p>
<p>After a successful login, the shell variables <code>ZFTP_USER</code>,
<code>ZFTP_ACCOUNT</code> and <code>ZFTP_PWD</code> are available; see ‘Variables’ below.</p>
<p>This command may be re-issued when a user is already logged in, and the
server will first be reinitialized for a new user.</p>
<p><code>params</code> [ <code>host</code> [ <code>user</code> [ <code>password</code> [ <code>account</code> ] ] ] ]</p>
<p><code>params</code> <code>-</code></p>
<p>Store the given parameters for a later <code>open</code> command with no arguments.
Only those given on the command line will be remembered. If no arguments
are given, the parameters currently set are printed, although the
password will appear as a line of stars; the return status is one if no
parameters were set, zero otherwise.</p>
<p>Any of the parameters may be specified as a ‘<code>?</code>’, which may need to be
quoted to protect it from shell expansion. In this case, the appropriate
parameter will be read from stdin as with the <code>login</code> subcommand,
including special handling of <code>password</code>. If the ‘<code>?</code>’ is followed by a
string, that is used as the prompt for reading the parameter instead of
the default message (any necessary punctuation and whitespace should be
included at the end of the prompt). The first letter of the parameter
(only) may be quoted with a ‘<code>\</code>’; hence an argument <code>&quot;\\$word&quot;</code>
guarantees that the string from the shell parameter <code>$word</code> will be
treated literally, whether or not it begins with a ‘<code>?</code>’.</p>
<p>If instead a single ‘<code>-</code>’ is given, the existing parameters, if any, are
deleted. In that case, calling <code>open</code> with no arguments will cause an
error.</p>
<p>The list of parameters is not deleted after a <code>close</code>, however it will
be deleted if the <code>zsh/zftp</code> module is unloaded.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">zftp params ftp.elsewhere.xx juser '?Password for juser: '
</code></pre>
</div>
<p>will store the host <code>ftp.elsewhere.xx</code> and the user <code>juser</code> and then
prompt the user for the corresponding password with the given prompt.</p>
<p><code>test</code></p>
<p>Test the connection; if the server has reported that it has closed the
connection (maybe due to a timeout), return status 2; if no connection
was open anyway, return status 1; else return status 0. The <code>test</code>
subcommand is silent, apart from messages printed by the <code>$ZFTP_VERBOSE</code>
mechanism, or error messages if the connection closes. There is no
network overhead for this test.</p>
<p>The test is only supported on systems with either the <code>select(2)</code> or
<code>poll(2)</code> system calls; otherwise the message ‘<code>not supported on this system</code>’ is printed instead.</p>
<p>The <code>test</code> subcommand will automatically be called at the start of any
other subcommand for the current session when a connection is open.</p>
<p><code>cd</code> <code>directory</code></p>
<p>Change the remote directory to <code>directory</code>. Also alters the shell
variable <code>ZFTP_PWD</code>.</p>
<p><code>cdup</code></p>
<p>Change the remote directory to the one higher in the directory tree.
Note that <code>cd ..</code> will also work correctly on non-UNIX systems.</p>
<p><code>dir</code> [ <code>arg</code> ... ]</p>
<p>Give a (verbose) listing of the remote directory. The <code>arg</code>s are passed
directly to the server. The command’s behaviour is implementation
dependent, but a UNIX server will typically interpret <code>arg</code>s as
arguments to the <code>ls</code> command and with no arguments return the result of
‘<code>ls -l</code>’. The directory is listed to standard output.</p>
<p><code>ls</code> [ <code>arg</code> ... ]</p>
<p>Give a (short) listing of the remote directory. With no <code>arg</code>, produces
a raw list of the files in the directory, one per line. Otherwise, up to
vagaries of the server implementation, behaves similar to <code>dir</code>.</p>
<p><code>type</code> [ <code>type</code> ]</p>
<p>Change the type for the transfer to <code>type</code>, or print the current type if
<code>type</code> is absent. The allowed values are ‘<code>A</code>’ (ASCII), ‘<code>I</code>’ (Image,
i.e. binary), or ‘<code>B</code>’ (a synonym for ‘<code>I</code>’).</p>
<p>The FTP default for a transfer is ASCII. However, if <code>zftp</code> finds that
the remote host is a UNIX machine with 8-bit byes, it will automatically
switch to using binary for file transfers upon <code>open</code>. This can
subsequently be overridden.</p>
<p>The transfer type is only passed to the remote host when a data
connection is established; this command involves no network overhead.</p>
<p><code>ascii</code></p>
<p>The same as <code>type A</code>.</p>
<p><code>binary</code></p>
<p>The same as <code>type I</code>.</p>
<p><code>mode</code> [ <code>S</code> | <code>B</code> ]</p>
<p>Set the mode type to stream (<code>S</code>) or block (<code>B</code>). Stream mode is the
default; block mode is not widely supported.</p>
<p><code>remote</code> <code>file</code> ...</p>
<p><code>local</code> [ <code>file</code> ... ]</p>
<p>Print the size and last modification time of the remote or local files.
If there is more than one item on the list, the name of the file is
printed first. The first number is the file size, the second is the last
modification time of the file in the format <code>CCYYMMDDhhmmSS</code> consisting
of year, month, date, hour, minutes and seconds in GMT. Note that this
format, including the length, is guaranteed, so that time strings can be
directly compared via the <code>[[</code> builtin’s <code>&lt;</code> and <code>&gt;</code> operators, even if
they are too long to be represented as integers.</p>
<p>Not all servers support the commands for retrieving this information. In
that case, the <code>remote</code> command will print nothing and return status 2,
compared with status 1 for a file not found.</p>
<p>The <code>local</code> command (but not <code>remote</code>) may be used with no arguments, in
which case the information comes from examining file descriptor zero.
This is the same file as seen by a <code>put</code> command with no further
redirection.</p>
<p><code>get</code> <code>file</code> ...</p>
<p>Retrieve all <code>file</code>s from the server, concatenating them and sending
them to standard output.</p>
<p><code>put</code> <code>file</code> ...</p>
<p>For each <code>file</code>, read a file from standard input and send that to the
remote host with the given name.</p>
<p><code>append</code> <code>file</code> ...</p>
<p>As <code>put</code>, but if the remote <code>file</code> already exists, data is appended to
it instead of overwriting it.</p>
<p><code>getat</code> <code>file</code> <code>point</code></p>
<p><code>putat</code> <code>file</code> <code>point</code></p>
<p><code>appendat</code> <code>file</code> <code>point</code></p>
<p>Versions of <code>get</code>, <code>put</code> and <code>append</code> which will start the transfer at
the given <code>point</code> in the remote <code>file</code>. This is useful for appending to
an incomplete local file. However, note that this ability is not
universally supported by servers (and is not quite the behaviour
specified by the standard).</p>
<p><code>delete</code> <code>file</code> ...</p>
<p>Delete the list of files on the server.</p>
<p><code>mkdir</code> <code>directory</code></p>
<p>Create a new directory <code>directory</code> on the server.</p>
<p><code>rmdir</code> <code>directory</code></p>
<p>Delete the directory <code>directory</code> on the server.</p>
<p><code>rename</code> <code>old-name</code> <code>new-name</code></p>
<p>Rename file <code>old-name</code> to <code>new-name</code> on the server.</p>
<p><code>site</code> <code>arg</code> ...</p>
<p>Send a host-specific command to the server. You will probably only need
this if instructed by the server to use it.</p>
<p><code>quote</code> <code>arg</code> ...</p>
<p>Send the raw FTP command sequence to the server. You should be familiar
with the FTP command set as defined in RFC959 before doing this. Useful
commands may include <code>STAT</code> and <code>HELP</code>. Note also the mechanism for
returning messages as described for the variable <code>ZFTP_VERBOSE</code> below,
in particular that all messages from the control connection are sent to
standard error.</p>
<p><code>close</code></p>
<p><code>quit</code></p>
<p>Close the current data connection. This unsets the shell parameters
<code>ZFTP_HOST</code>, <code>ZFTP_PORT</code>, <code>ZFTP_IP</code>, <code>ZFTP_SYSTEM</code>, <code>ZFTP_USER</code>,
<code>ZFTP_ACCOUNT</code>, <code>ZFTP_PWD</code>, <code>ZFTP_TYPE</code> and <code>ZFTP_MODE</code>.</p>
<p><code>session</code> [ <code>sessname</code> ]</p>
<p>Allows multiple FTP sessions to be used at once. The name of the session
is an arbitrary string of characters; the default session is called
‘<code>default</code>’. If this command is called without an argument, it will
list all the current sessions; with an argument, it will either switch
to the existing session called <code>sessname</code>, or create a new session of
that name.</p>
<p>Each session remembers the status of the connection, the set of
connection-specific shell parameters (the same set as are unset when a
connection closes, as given in the description of <code>close</code>), and any user
parameters specified with the <code>params</code> subcommand. Changing to a
previous session restores those values; changing to a new session
initialises them in the same way as if <code>zftp</code> had just been loaded. The
name of the current session is given by the parameter <code>ZFTP_SESSION</code>.</p>
<p><code>rmsession</code> [ <code>sessname</code> ]</p>
<p>Delete a session; if a name is not given, the current session is
deleted. If the current session is deleted, the earliest existing
session becomes the new current session, otherwise the current session
is not changed. If the session being deleted is the only one, a new
session called ‘<code>default</code>’ is created and becomes the current session;
note that this is a new session even if the session being deleted is
also called ‘<code>default</code>’. It is recommended that sessions not be deleted
while background commands which use <code>zftp</code> are still active.</p>
<hr />
<p><span id="Parameters-2"></span></p>
<h3 id="22312-parameters"><a class="header" href="#22312-parameters">22.31.2 Parameters</a></h3>
<p><span id="index-zftp_002c-parameters"></span></p>
<p>The following shell parameters are used by <code>zftp</code>. Currently none of
them are special.</p>
<p><span id="index-ZFTP_005fTMOUT"></span></p>
<p><code>ZFTP_TMOUT</code></p>
<p>Integer. The time in seconds to wait for a network operation to complete
before returning an error. If this is not set when the module is loaded,
it will be given the default value 60. A value of zero turns off
timeouts. If a timeout occurs on the control connection it will be
closed. Use a larger value if this occurs too frequently.</p>
<p><span id="index-ZFTP_005fIP"></span></p>
<p><code>ZFTP_IP</code></p>
<p>Readonly. The IP address of the current connection in dot notation.</p>
<p><span id="index-ZFTP_005fHOST"></span></p>
<p><code>ZFTP_HOST</code></p>
<p>Readonly. The hostname of the current remote server. If the host was
opened as an IP number, <code>ZFTP_HOST</code> contains that instead; this saves
the overhead for a name lookup, as IP numbers are most commonly used
when a nameserver is unavailable.</p>
<p><span id="index-ZFTP_005fPORT"></span></p>
<p><code>ZFTP_PORT</code></p>
<p>Readonly. The number of the remote TCP port to which the connection is
open (even if the port was originally specified as a named service).
Usually this is the standard FTP port, 21.</p>
<p>In the unlikely event that your system does not have the appropriate
conversion functions, this appears in network byte order. If your system
is little-endian, the port then consists of two swapped bytes and the
standard port will be reported as 5376. In that case, numeric ports
passed to <code>zftp open</code> will also need to be in this format.</p>
<p><span id="index-ZFTP_005fSYSTEM"></span></p>
<p><code>ZFTP_SYSTEM</code></p>
<p>Readonly. The system type string returned by the server in response to
an FTP <code>SYST</code> request. The most interesting case is a string beginning
<code>&quot;UNIX Type: L8&quot;</code>, which ensures maximum compatibility with a local UNIX
host.</p>
<p><span id="index-ZFTP_005fTYPE"></span></p>
<p><code>ZFTP_TYPE</code></p>
<p>Readonly. The type to be used for data transfers , either ‘<code>A</code>’ or
‘<code>I</code>’. Use the <code>type</code> subcommand to change this.</p>
<p><span id="index-ZFTP_005fUSER"></span></p>
<p><code>ZFTP_USER</code></p>
<p>Readonly. The username currently logged in, if any.</p>
<p><span id="index-ZFTP_005fACCOUNT"></span></p>
<p><code>ZFTP_ACCOUNT</code></p>
<p>Readonly. The account name of the current user, if any. Most servers do
not require an account name.</p>
<p><span id="index-ZFTP_005fPWD"></span></p>
<p><code>ZFTP_PWD</code></p>
<p>Readonly. The current directory on the server.</p>
<p><span id="index-ZFTP_005fCODE"></span></p>
<p><code>ZFTP_CODE</code></p>
<p>Readonly. The three digit code of the last FTP reply from the server as
a string. This can still be read after the connection is closed, and is
not changed when the current session changes.</p>
<p><span id="index-ZFTP_005fREPLY"></span></p>
<p><code>ZFTP_REPLY</code></p>
<p>Readonly. The last line of the last reply sent by the server. This can
still be read after the connection is closed, and is not changed when
the current session changes.</p>
<p><span id="index-ZFTP_005fSESSION"></span></p>
<p><code>ZFTP_SESSION</code></p>
<p>Readonly. The name of the current FTP session; see the description of
the <code>session</code> subcommand.</p>
<p><span id="index-ZFTP_005fPREFS"></span></p>
<p><code>ZFTP_PREFS</code></p>
<p>A string of preferences for altering aspects of <code>zftp</code>’s behaviour. Each
preference is a single character. The following are defined:</p>
<ul>
<li>
<p><code>P</code><br />
Passive: attempt to make the remote server initiate data transfers.
This is slightly more efficient than sendport mode. If the letter
<code>S</code> occurs later in the string, <code>zftp</code> will use sendport mode if
passive mode is not available.</p>
</li>
<li>
<p><code>S</code><br />
Sendport: initiate transfers by the FTP <code>PORT</code> command. If this
occurs before any <code>P</code> in the string, passive mode will never be
attempted.</p>
</li>
<li>
<p><code>D</code><br />
Dumb: use only the bare minimum of FTP commands. This prevents the
variables <code>ZFTP_SYSTEM</code> and <code>ZFTP_PWD</code> from being set, and will mean
all connections default to ASCII type. It may prevent <code>ZFTP_SIZE</code>
from being set during a transfer if the server does not send it
anyway (many servers do).</p>
</li>
</ul>
<p>If <code>ZFTP_PREFS</code> is not set when <code>zftp</code> is loaded, it will be set to a
default of ‘<code>PS</code>’, i.e. use passive mode if available, otherwise fall
back to sendport mode.</p>
<p><span id="index-ZFTP_005fVERBOSE"></span></p>
<p><code>ZFTP_VERBOSE</code></p>
<p>A string of digits between 0 and 5 inclusive, specifying which responses
from the server should be printed. All responses go to standard error.
If any of the numbers 1 to 5 appear in the string, raw responses from
the server with reply codes beginning with that digit will be printed to
standard error. The first digit of the three digit reply code is defined
by RFC959 to correspond to:</p>
<ul>
<li>
<p>1.<br />
A positive preliminary reply.</p>
</li>
<li>
<p>2.<br />
A positive completion reply.</p>
</li>
<li>
<p>3.<br />
A positive intermediate reply.</p>
</li>
<li>
<p>4.<br />
A transient negative completion reply.</p>
</li>
<li>
<p>5.<br />
A permanent negative completion reply.</p>
</li>
</ul>
<p>It should be noted that, for unknown reasons, the reply ‘Service not
available’, which forces termination of a connection, is classified as
421, i.e. ‘transient negative’, an interesting interpretation of the
word ‘transient’.</p>
<p>The code 0 is special: it indicates that all but the last line of
multiline replies read from the server will be printed to standard error
in a processed format. By convention, servers use this mechanism for
sending information for the user to read. The appropriate reply code, if
it matches the same response, takes priority.</p>
<p>If <code>ZFTP_VERBOSE</code> is not set when <code>zftp</code> is loaded, it will be set to
the default value <code>450</code>, i.e., messages destined for the user and all
errors will be printed. A null string is valid and specifies that no
messages should be printed.</p>
<hr />
<p><span id="Functions-1"></span></p>
<h3 id="22313-functions"><a class="header" href="#22313-functions">22.31.3 Functions</a></h3>
<p><span id="index-zftp_002c-functions"></span></p>
<p><span id="index-zftp_005fchpwd_002c-specification"></span></p>
<p><code>zftp_chpwd</code></p>
<p>If this function is set by the user, it is called every time the
directory changes on the server, including when a user is logged in, or
when a connection is closed. In the last case, <code>$ZFTP_PWD</code> will be
unset; otherwise it will reflect the new directory.</p>
<p><span id="index-zftp_005fprogress_002c-specification"></span></p>
<p><code>zftp_progress</code></p>
<p>If this function is set by the user, it will be called during a <code>get</code>,
<code>put</code> or <code>append</code> operation each time sufficient data has been received
from the host. During a <code>get</code>, the data is sent to standard output, so
it is vital that this function should write to standard error or
directly to the terminal, <em>not</em> to standard output.</p>
<p>When it is called with a transfer in progress, the following additional
shell parameters are set:</p>
<p><span id="index-ZFTP_005fFILE"></span></p>
<p><code>ZFTP_FILE</code></p>
<p>The name of the remote file being transferred from or to.</p>
<p><span id="index-ZFTP_005fTRANSFER"></span></p>
<p><code>ZFTP_TRANSFER</code></p>
<p>A <code>G</code> for a <code>get</code> operation and a <code>P</code> for a <code>put</code> operation.</p>
<p><span id="index-ZFTP_005fSIZE"></span></p>
<p><code>ZFTP_SIZE</code></p>
<p>The total size of the complete file being transferred: the same as the
first value provided by the <code>remote</code> and <code>local</code> subcommands for a
particular file. If the server cannot supply this value for a remote
file being retrieved, it will not be set. If input is from a pipe the
value may be incorrect and correspond simply to a full pipe buffer.</p>
<p><span id="index-ZFTP_005fCOUNT"></span></p>
<p><code>ZFTP_COUNT</code></p>
<p>The amount of data so far transferred; a number between zero and
<code>$ZFTP_SIZE</code>, if that is set. This number is always available.</p>
<p>The function is initially called with <code>ZFTP_TRANSFER</code> set appropriately
and <code>ZFTP_COUNT</code> set to zero. After the transfer is finished, the
function will be called one more time with <code>ZFTP_TRANSFER</code> set to <code>GF</code>
or <code>PF</code>, in case it wishes to tidy up. It is otherwise never called
twice with the same value of <code>ZFTP_COUNT</code>.</p>
<p>Sometimes the progress meter may cause disruption. It is up to the user
to decide whether the function should be defined and to use <code>unfunction</code>
when necessary.</p>
<hr />
<p><span id="Problems"></span></p>
<h3 id="22314-problems"><a class="header" href="#22314-problems">22.31.4 Problems</a></h3>
<p><span id="index-zftp_002c-problems"></span></p>
<p>A connection may not be opened in the left hand side of a pipe as this
occurs in a subshell and the file information is not updated in the main
shell. In the case of type or mode changes or closing the connection in
a subshell, the information is returned but variables are not updated
until the next call to <code>zftp</code>. Other status changes in subshells will
not be reflected by changes to the variables (but should be otherwise
harmless).</p>
<p>Deleting sessions while a <code>zftp</code> command is active in the background can
have unexpected effects, even if it does not use the session being
deleted. This is because all shell subprocesses share information on the
state of all connections, and deleting a session changes the ordering of
that information.</p>
<p>On some operating systems, the control connection is not valid after a
fork(), so that operations in subshells, on the left hand side of a
pipeline, or in the background are not possible, as they should be. This
is presumably a bug in the operating system.</p>
<hr />
<p><span id="The-zsh_002fzle-Module"></span>
<span id="The-zsh_002fzle-Module-1"></span></p>
<h2 id="2232-the-zshzle-module"><a class="header" href="#2232-the-zshzle-module">22.32 The zsh/zle Module</a></h2>
<p>The <code>zsh/zle</code> module contains the Zsh Line Editor. See <a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh Line
Editor</a>.</p>
<hr />
<p><span id="The-zsh_002fzleparameter-Module"></span>
<span id="The-zsh_002fzleparameter-Module-1"></span></p>
<h2 id="2233-the-zshzleparameter-module"><a class="header" href="#2233-the-zshzleparameter-module">22.33 The zsh/zleparameter Module</a></h2>
<p><span id="index-parameters_002c-special-2"></span></p>
<p>The <code>zsh/zleparameter</code> module defines two special parameters that can be
used to access internal information of the Zsh Line Editor (see <a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh
Line Editor</a>).</p>
<p><span id="index-keymaps-2"></span></p>
<p><code>keymaps</code></p>
<p>This array contains the names of the keymaps currently defined.</p>
<p><span id="index-widgets-1"></span></p>
<p><code>widgets</code></p>
<p>This associative array contains one entry per widget. The name of the
widget is the key and the value gives information about the widget. It
is either the string ‘<code>builtin</code>’ for builtin widgets, a string of the
form ‘<code>user:``name</code>’ for user-defined widgets, where <code>name</code> is the name
of the shell function implementing the widget, a string of the form
‘<code>completion:``type``:``name</code>’ for completion widgets, or a null value
if the widget is not yet fully defined. In the penultimate case, <code>type</code>
is the name of the builtin widget the completion widget imitates in its
behavior and <code>name</code> is the name of the shell function implementing the
completion widget.</p>
<hr />
<p><span id="The-zsh_002fzprof-Module"></span>
<span id="The-zsh_002fzprof-Module-1"></span></p>
<h2 id="2234-the-zshzprof-module"><a class="header" href="#2234-the-zshzprof-module">22.34 The zsh/zprof Module</a></h2>
<p><span id="index-functions_002c-profiling"></span></p>
<p>When loaded, the <code>zsh/zprof</code> causes shell functions to be profiled. The
profiling results can be obtained with the <code>zprof</code> builtin command made
available by this module. There is no way to turn profiling off other
than unloading the module.</p>
<p><span id="index-zprof"></span></p>
<p><code>zprof</code> [ <code>-c</code> ]</p>
<p>Without the <code>-c</code> option, <code>zprof</code> lists profiling results to standard
output. The format is comparable to that of commands like <code>gprof</code>.</p>
<p>At the top there is a summary listing all functions that were called at
least once. This summary is sorted in decreasing order of the amount of
time spent in each. The lines contain the number of the function in
order, which is used in other parts of the list in suffixes of the form
‘<code>[``num``]</code>’, then the number of calls made to the function. The next
three columns list the time in milliseconds spent in the function and
its descendants, the average time in milliseconds spent in the function
and its descendants per call and the percentage of time spent in all
shell functions used in this function and its descendants. The following
three columns give the same information, but counting only the time
spent in the function itself. The final column shows the name of the
function.</p>
<p>After the summary, detailed information about every function that was
invoked is listed, sorted in decreasing order of the amount of time
spent in each function and its descendants. Each of these entries
consists of descriptions for the functions that called the function
described, the function itself, and the functions that were called from
it. The description for the function itself has the same format as in
the summary (and shows the same information). The other lines don’t show
the number of the function at the beginning and have their function
named indented to make it easier to distinguish the line showing the
function described in the section from the surrounding lines.</p>
<p>The information shown in this case is almost the same as in the summary,
but only refers to the call hierarchy being displayed. For example, for
a calling function the column showing the total running time lists the
time spent in the described function and its descendants only for the
times when it was called from that particular calling function.
Likewise, for a called function, this columns lists the total time spent
in the called function and its descendants only for the times when it
was called from the function described.</p>
<p>Also in this case, the column showing the number of calls to a function
also shows a slash and then the total number of invocations made to the
called function.</p>
<p>As long as the <code>zsh/zprof</code> module is loaded, profiling will be done and
multiple invocations of the <code>zprof</code> builtin command will show the times
and numbers of calls since the module was loaded. With the <code>-c</code> option,
the <code>zprof</code> builtin command will reset its internal counters and will
not show the listing.</p>
<hr />
<p><span id="The-zsh_002fzpty-Module"></span>
<span id="The-zsh_002fzpty-Module-1"></span></p>
<h2 id="2235-the-zshzpty-module"><a class="header" href="#2235-the-zshzpty-module">22.35 The zsh/zpty Module</a></h2>
<p>The <code>zsh/zpty</code> module offers one builtin:</p>
<p><span id="index-zpty"></span></p>
<p><code>zpty</code> [ <code>-e</code> ] [ <code>-b</code> ] <code>name</code> [ <code>arg</code> ... ]</p>
<p>The arguments following <code>name</code> are concatenated with spaces between,
then executed as a command, as if passed to the <code>eval</code> builtin. The
command runs under a newly assigned pseudo-terminal; this is useful for
running commands non-interactively which expect an interactive
environment. The <code>name</code> is not part of the command, but is used to refer
to this command in later calls to <code>zpty</code>.</p>
<p>With the <code>-e</code> option, the pseudo-terminal is set up so that input
characters are echoed.</p>
<p>With the <code>-b</code> option, input to and output from the pseudo-terminal are
made non-blocking.</p>
<p>The shell parameter <code>REPLY</code> is set to the file descriptor assigned to
the master side of the pseudo-terminal. This allows the terminal to be
monitored with ZLE descriptor handlers (see <a href="Zsh-Line-Editor.html#Zle-Builtins">Zle
Builtins</a>) or manipulated with
<code>sysread</code> and <code>syswrite</code> (see <a href="Zsh-Modules.html#The-zsh_002fsystem-Module">The zsh/system
Module</a>). <em>Warning</em>: Use of <code>sysread</code> and
<code>syswrite</code> is <em>not</em> recommended; use <code>zpty -r</code> and <code>zpty -w</code> unless you
know exactly what you are doing.</p>
<p><code>zpty</code> <code>-d</code> [ <code>name</code> ... ]</p>
<p>The second form, with the <code>-d</code> option, is used to delete commands
previously started, by supplying a list of their <code>name</code>s. If no <code>name</code>
is given, all commands are deleted. Deleting a command causes the HUP
signal to be sent to the corresponding process.</p>
<p><code>zpty</code> <code>-w</code> [ <code>-n</code> ] <code>name</code> [ <code>string</code> ... ]</p>
<p>The <code>-w</code> option can be used to send the to command <code>name</code> the given
<code>string</code>s as input (separated by spaces). If the <code>-n</code> option is <em>not</em>
given, a newline is added at the end.</p>
<p>If no <code>string</code> is provided, the standard input is copied to the
pseudo-terminal; this may stop before copying the full input if the
pseudo-terminal is non-blocking. The exact input is always copied: the
<code>-n</code> option is not applied.</p>
<p>Note that the command under the pseudo-terminal sees this input as if it
were typed, so beware when sending special tty driver characters such as
word-erase, line-kill, and end-of-file.</p>
<p><code>zpty</code> <code>-r</code> [ <code>-mt</code> ] <code>name</code> [ <code>param</code> [ <code>pattern</code> ] ]</p>
<p>The <code>-r</code> option can be used to read the output of the command <code>name</code>.
With only a <code>name</code> argument, the output read is copied to the standard
output. Unless the pseudo-terminal is non-blocking, copying continues
until the command under the pseudo-terminal exits; when non-blocking,
only as much output as is immediately available is copied. The return
status is zero if any output is copied.</p>
<p>When also given a <code>param</code> argument, at most one line is read and stored
in the parameter named <code>param</code>. Less than a full line may be read if the
pseudo-terminal is non-blocking. The return status is zero if at least
one character is stored in <code>param</code>.</p>
<p>If a <code>pattern</code> is given as well, output is read until the whole string
read matches the <code>pattern</code>, even in the non-blocking case. The return
status is zero if the string read matches the pattern, or if the command
has exited but at least one character could still be read. If the option
<code>-m</code> is present, the return status is zero only if the pattern matches.
As of this writing, a maximum of one megabyte of output can be consumed
this way; if a full megabyte is read without matching the pattern, the
return status is non-zero.</p>
<p>In all cases, the return status is non-zero if nothing could be read,
and is <code>2</code> if this is because the command has finished.</p>
<p>If the <code>-r</code> option is combined with the <code>-t</code> option, <code>zpty</code> tests
whether output is available before trying to read. If no output is
available, <code>zpty</code> immediately returns the status <code>1</code>. When used with a
<code>pattern</code>, the behaviour on a failed poll is similar to when the command
has exited: the return value is zero if at least one character could
still be read even if the pattern failed to match.</p>
<p><code>zpty</code> <code>-t</code> <code>name</code></p>
<p>The <code>-t</code> option without the <code>-r</code> option can be used to test whether the
command <code>name</code> is still running. It returns a zero status if the command
is running and a non-zero value otherwise.</p>
<p><code>zpty</code> [ <code>-L</code> ]</p>
<p>The last form, without any arguments, is used to list the commands
currently defined. If the <code>-L</code> option is given, this is done in the form
of calls to the <code>zpty</code> builtin.</p>
<hr />
<p><span id="The-zsh_002fzselect-Module"></span>
<span id="The-zsh_002fzselect-Module-1"></span></p>
<h2 id="2236-the-zshzselect-module"><a class="header" href="#2236-the-zshzselect-module">22.36 The zsh/zselect Module</a></h2>
<p>The <code>zsh/zselect</code> module makes available one builtin command:</p>
<p><span id="index-zselect"></span>
<span id="index-select_002c-system-call"></span>
<span id="index-file-descriptors_002c-waiting-for"></span></p>
<p><code>zselect</code> [ <code>-rwe</code> ] [ <code>-t</code> <code>timeout</code> ] [ <code>-a</code> <code>array</code> ] [ <code>-A</code>
<code>assoc</code> ] [ <code>fd</code> ... ]</p>
<p>The <code>zselect</code> builtin is a front-end to the ‘select’ system call, which
blocks until a file descriptor is ready for reading or writing, or has
an error condition, with an optional timeout. If this is not available
on your system, the command prints an error message and returns status 2
(normal errors return status 1). For more information, see your systems
documentation for man page select(3). Note there is no connection with
the shell builtin of the same name.</p>
<p>Arguments and options may be intermingled in any order. Non-option
arguments are file descriptors, which must be decimal integers. By
default, file descriptors are to be tested for reading, i.e. <code>zselect</code>
will return when data is available to be read from the file descriptor,
or more precisely, when a read operation from the file descriptor will
not block. After a <code>-r</code>, <code>-w</code> and <code>-e</code>, the given file descriptors are
to be tested for reading, writing, or error conditions. These options
and an arbitrary list of file descriptors may be given in any order.</p>
<p>(The presence of an ‘error condition’ is not well defined in the
documentation for many implementations of the select system call.
According to recent versions of the POSIX specification, it is really an
<em>exception</em> condition, of which the only standard example is out-of-band
data received on a socket. So zsh users are unlikely to find the <code>-e</code>
option useful.)</p>
<p>The option ‘<code>-t</code> <code>timeout</code>’ specifies a timeout in hundredths of a
second. This may be zero, in which case the file descriptors will simply
be polled and <code>zselect</code> will return immediately. It is possible to call
zselect with no file descriptors and a non-zero timeout for use as a
finer-grained replacement for ‘sleep’; note, however, the return status
is always 1 for a timeout.</p>
<p>The option ‘<code>-a</code> <code>array</code>’ indicates that <code>array</code> should be set to
indicate the file descriptor(s) which are ready. If the option is not
given, the array <code>reply</code> will be used for this purpose. The array will
contain a string similar to the arguments for <code>zselect</code>. For example,</p>
<div class="example">
<pre><code class="language-example">zselect -t 0 -r 0 -w 1
</code></pre>
</div>
<p>might return immediately with status 0 and <code>$reply</code> containing ‘<code>-r 0 -w 1</code>’ to show that both file descriptors are ready for the requested
operations.</p>
<p>The option ‘<code>-A</code> <code>assoc</code>’ indicates that the associative array <code>assoc</code>
should be set to indicate the file descriptor(s) which are ready. This
option overrides the option <code>-a</code>, nor will <code>reply</code> be modified. The keys
of <code>assoc</code> are the file descriptors, and the corresponding values are
any of the characters ‘<code>rwe</code>’ to indicate the condition.</p>
<p>The command returns status 0 if some file descriptors are ready for
reading. If the operation timed out, or a timeout of 0 was given and no
file descriptors were ready, or there was an error, it returns status 1
and the array will not be set (nor modified in any way). If there was an
error in the select operation the appropriate error message is printed.</p>
<hr />
<p><span id="The-zsh_002fzutil-Module"></span>
<span id="The-zsh_002fzutil-Module-1"></span></p>
<h2 id="2237-the-zshzutil-module"><a class="header" href="#2237-the-zshzutil-module">22.37 The zsh/zutil Module</a></h2>
<p><span id="index-builtins_002c-utility"></span></p>
<p>The <code>zsh/zutil</code> module only adds some builtins:</p>
<p><span id="index-zstyle"></span></p>
<p><code>zstyle</code> [ <code>-L</code> [ <code>metapattern</code> [ <code>style</code> ] ] ]</p>
<p><code>zstyle</code> [ <code>-e</code> | <code>-</code> | <code>-``-</code> ] <code>pattern</code> <code>style</code> <code>string</code> ...</p>
<p><code>zstyle -d</code> [ <code>pattern</code> [ <code>style</code> ... ] ]</p>
<p><code>zstyle -g</code> <code>name</code> [ <code>pattern</code> [ <code>style</code> ] ]</p>
<p><code>zstyle -</code>{<code>a</code>|<code>b</code>|<code>s</code>} <code>context</code> <code>style</code> <code>name</code> [ <code>sep</code> ]</p>
<p><code>zstyle -</code>{<code>T</code>|<code>t</code>} <code>context</code> <code>style</code> [ <code>string</code> ... ]</p>
<p><code>zstyle -m</code> <code>context</code> <code>style</code> <code>pattern</code></p>
<p>This builtin command is used to define and lookup styles. Styles are
pairs of names and values, where the values consist of any number of
strings. They are stored together with patterns and lookup is done by
giving a string, called the ‘<em>context</em>’, which is matched against the
patterns. The definition stored for the most specific pattern that
matches will be returned.</p>
<p>A pattern is considered to be more specific than another if it contains
more components (substrings separated by colons) or if the patterns for
the components are more specific, where simple strings are considered to
be more specific than patterns and complex patterns are considered to be
more specific than the pattern ‘<code>*</code>’. A ‘<code>*</code>’ in the pattern will match
zero or more characters in the context; colons are not treated specially
in this regard. If two patterns are equally specific, the tie is broken
in favour of the pattern that was defined first.</p>
<p><em>Example</em></p>
<p>For example, to define your preferred form of precipitation depending on
which city you’re in, you might set the following in your <code>zshrc</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':weather:europe:*' preferred-precipitation rain
zstyle ':weather:europe:germany:* preferred-precipitation none
zstyle ':weather:europe:germany:*:munich' preferred-precipitation snow
</code></pre>
</div>
<p>Then, the fictional ‘<code>weather</code>’ plugin might run under the hood a
command such as</p>
<div class="example">
<pre><code class="language-example">zstyle -s &quot;:weather:${continent}:${country}:${county}:${city}&quot; preferred-precipitation REPLY
</code></pre>
</div>
<p>in order to retrieve your preference into the scalar variable <code>$REPLY</code>.</p>
<p><em>Usage</em></p>
<p>The forms that operate on patterns are the following.</p>
<ul>
<li>
<p><code>zstyle</code> [ <code>-L</code> [ <code>metapattern</code> [ <code>style</code> ] ] ]<br />
Without arguments, lists style definitions. Styles are shown in
alphabetic order and patterns are shown in the order <code>zstyle</code> will
test them.</p>
<p>If the <code>-L</code> option is given, listing is done in the form of calls to
<code>zstyle</code>. The optional first argument, <code>metapattern</code>, is a pattern
which will be matched against the string supplied as <code>pattern</code> when
the style was defined. Note: this means, for example, ‘<code>zstyle -L &quot;:completion:*&quot;</code>’ will match any supplied pattern beginning
‘<code>:completion:</code>’, not just <code>&quot;:completion:*&quot;</code>: use
<code>’:completion:\*’</code> to match that. The optional second argument
limits the output to a specific <code>style</code> (not a pattern). <code>-L</code> is not
compatible with any other options.</p>
</li>
<li>
<p><code>zstyle</code> [ <code>-</code> | <code>-``-</code> | <code>-e</code> ] <code>pattern</code> <code>style</code> <code>string</code> ...<br />
<span id="index-reply_002c-use-of-4"></span></p>
<p>Defines the given <code>style</code> for the <code>pattern</code> with the <code>string</code>s as
the value. If the <code>-e</code> option is given, the <code>string</code>s will be
concatenated (separated by spaces) and the resulting string will be
evaluated (in the same way as it is done by the <code>eval</code> builtin
command) when the style is looked up. In this case the parameter
‘<code>reply</code>’ must be assigned to set the strings returned after the
evaluation. Before evaluating the value, <code>reply</code> is unset, and if it
is still unset after the evaluation, the style is treated as if it
were not set.</p>
</li>
<li>
<p><code>zstyle -d</code> [ <code>pattern</code> [ <code>style</code> ... ] ]<br />
Delete style definitions. Without arguments all definitions are
deleted, with a <code>pattern</code> all definitions for that pattern are
deleted and if any <code>style</code>s are given, then only those styles are
deleted for the <code>pattern</code>.</p>
</li>
<li>
<p><code>zstyle -g</code> <code>name</code> [ <code>pattern</code> [ <code>style</code> ] ]<br />
Retrieve a style definition. The <code>name</code> is used as the name of an
array in which the results are stored. Without any further
arguments, all patterns defined are returned. With a <code>pattern</code> the
styles defined for that pattern are returned and with both a
<code>pattern</code> and a <code>style</code>, the value strings of that combination is
returned.</p>
</li>
</ul>
<p>The other forms can be used to look up or test styles for a given
context.</p>
<ul>
<li>
<p><code>zstyle -s</code> <code>context</code> <code>style</code> <code>name</code> [ <code>sep</code> ]<br />
The parameter <code>name</code> is set to the value of the style interpreted as
a string. If the value contains several strings they are
concatenated with spaces (or with the <code>sep</code> string if that is given)
between them.</p>
<p>Return <code>0</code> if the style is set, <code>1</code> otherwise.</p>
</li>
<li>
<p><code>zstyle -b</code> <code>context</code> <code>style</code> <code>name</code><br />
The value is stored in <code>name</code> as a boolean, i.e. as the string
‘<code>yes</code>’ if the value has only one string and that string is equal
to one of ‘<code>yes</code>’, ‘<code>true</code>’, ‘<code>on</code>’, or ‘<code>1</code>’. If the value is any
other string or has more than one string, the parameter is set to
‘<code>no</code>’.</p>
<p>Return <code>0</code> if <code>name</code> is set to ‘<code>yes</code>’, <code>1</code> otherwise.</p>
</li>
<li>
<p><code>zstyle -a</code> <code>context</code> <code>style</code> <code>name</code><br />
The value is stored in <code>name</code> as an array. If <code>name</code> is declared as
an associative array, the first, third, etc. strings are used as the
keys and the other strings are used as the values.</p>
<p>Return <code>0</code> if the style is set, <code>1</code> otherwise.</p>
</li>
<li>
<p><code>zstyle -t</code> <code>context</code> <code>style</code> [ <code>string</code> ... ]<br />
<code>zstyle -T</code> <code>context</code> <code>style</code> [ <code>string</code> ... ]<br />
Test the value of a style, i.e. the <code>-t</code> option only returns a
status (sets <code>$?</code>). Without any <code>string</code> the return status is zero
if the style is defined for at least one matching pattern, has only
one string in its value, and that is equal to one of ‘<code>true</code>’,
‘<code>yes</code>’, ‘<code>on</code>’ or ‘<code>1</code>’. If any <code>string</code>s are given the status is
zero if and only if at least one of the <code>string</code>s is equal to at
least one of the strings in the value. If the style is defined but
doesn’t match, the return status is <code>1</code>. If the style is not
defined, the status is <code>2</code>.</p>
<p>The <code>-T</code> option tests the values of the style like <code>-t</code>, but it
returns status zero (rather than <code>2</code>) if the style is not defined
for any matching pattern.</p>
</li>
<li>
<p><code>zstyle -m</code> <code>context</code> <code>style</code> <code>pattern</code><br />
Match a value. Returns status zero if the <code>pattern</code> matches at least
one of the strings in the value.</p>
</li>
</ul>
<p><span id="index-zformat"></span></p>
<p><code>zformat -f</code> <code>param</code> <code>format</code> <code>spec</code> ...</p>
<p><code>zformat -a</code> <code>array</code> <code>sep</code> <code>spec</code> ...</p>
<p>This builtin provides two different forms of formatting. The first form
is selected with the <code>-f</code> option. In this case the <code>format</code> string will
be modified by replacing sequences starting with a percent sign in it
with strings from the <code>spec</code>s. Each <code>spec</code> should be of the form
‘<code>char``:``string</code>’ which will cause every appearance of the sequence
‘<code>%``char</code>’ in <code>format</code> to be replaced by the <code>string</code>. The ‘<code>%</code>’
sequence may also contain optional minimum and maximum field width
specifications between the ‘<code>%</code>’ and the ‘<code>char</code>’ in the form
‘<code>%``min``.``max``c</code>’, i.e. the minimum field width is given first and
if the maximum field width is used, it has to be preceded by a dot.
Specifying a minimum field width makes the result be padded with spaces
to the right if the <code>string</code> is shorter than the requested width.
Padding to the left can be achieved by giving a negative minimum field
width. If a maximum field width is specified, the <code>string</code> will be
truncated after that many characters. After all ‘<code>%</code>’ sequences for the
given <code>spec</code>s have been processed, the resulting string is stored in the
parameter <code>param</code>.</p>
<p>The <code>%</code>-escapes also understand ternary expressions in the form used by
prompts. The <code>%</code> is followed by a ‘<code>(</code>’ and then an ordinary format
specifier character as described above. There may be a set of digits
either before or after the ‘<code>(</code>’; these specify a test number, which
defaults to zero. Negative numbers are also allowed. An arbitrary
delimiter character follows the format specifier, which is followed by a
piece of ‘true’ text, the delimiter character again, a piece of ‘false’
text, and a closing parenthesis. The complete expression (without the
digits) thus looks like ‘<code>%(``X``.``text1``.``text2``)</code>’, except that
the ‘<code>.</code>’ character is arbitrary. The value given for the format
specifier in the <code>char``:``string</code> expressions is evaluated as a
mathematical expression, and compared with the test number. If they are
the same, <code>text1</code> is output, else <code>text2</code> is output. A parenthesis may
be escaped in <code>text2</code> as <code>%)</code>. Either of <code>text1</code> or <code>text2</code> may contain
nested <code>%</code>-escapes.</p>
<p>For example:</p>
<div class="example">
<pre><code class="language-example">zformat -f REPLY &quot;The answer is '%3(c.yes.no)'.&quot; c:3
</code></pre>
</div>
<p>outputs &quot;The answer is ’yes’.&quot; to <code>REPLY</code> since the value for the format
specifier <code>c</code> is 3, agreeing with the digit argument to the ternary
expression.</p>
<p>The second form, using the <code>-a</code> option, can be used for aligning
strings. Here, the <code>spec</code>s are of the form ‘<code>left``:``right</code>’ where
‘<code>left</code>’ and ‘<code>right</code>’ are arbitrary strings. These strings are
modified by replacing the colons by the <code>sep</code> string and padding the
<code>left</code> strings with spaces to the right so that the <code>sep</code> strings in the
result (and hence the <code>right</code> strings after them) are all aligned if the
strings are printed below each other. All strings without a colon are
left unchanged and all strings with an empty <code>right</code> string have the
trailing colon removed. In both cases the lengths of the strings are not
used to determine how the other strings are to be aligned. A colon in
the <code>left</code> string can be escaped with a backslash. The resulting strings
are stored in the <code>array</code>.</p>
<p><span id="index-zregexparse"></span></p>
<p><code>zregexparse</code></p>
<p>This implements some internals of the <code>_regex_arguments</code> function.</p>
<p><span id="index-zparseopts"></span></p>
<p><code>zparseopts</code> [ <code>-D</code> <code>-E</code> <code>-F</code> <code>-K</code> <code>-M</code> ] [ <code>-a</code> <code>array</code> ] [ <code>-A</code>
<code>assoc</code> ] [ <code>-</code> ] <code>spec</code> ...</p>
<p>This builtin simplifies the parsing of options in positional parameters,
i.e. the set of arguments given by <code>$*</code>. Each <code>spec</code> describes one
option and must be of the form ‘<code>opt</code>[<code>=``array</code>]’. If an option
described by <code>opt</code> is found in the positional parameters it is copied
into the <code>array</code> specified with the <code>-a</code> option; if the optional
‘<code>=``array</code>’ is given, it is instead copied into that array, which
should be declared as a normal array and never as an associative array.</p>
<p>Note that it is an error to give any <code>spec</code> without an ‘<code>=``array</code>’
unless one of the <code>-a</code> or <code>-A</code> options is used.</p>
<p>Unless the <code>-E</code> option is given, parsing stops at the first string that
isn’t described by one of the <code>spec</code>s. Even with <code>-E</code>, parsing always
stops at a positional parameter equal to ‘<code>-</code>’ or ‘<code>-``-</code>’. See also
<code>-F</code>.</p>
<p>The <code>opt</code> description must be one of the following. Any of the special
characters can appear in the option name provided it is preceded by a
backslash.</p>
<ul>
<li>
<p><code>name</code><br />
<code>name``+</code><br />
The <code>name</code> is the name of the option without the leading ‘<code>-</code>’. To
specify a GNU-style long option, one of the usual two leading ‘<code>-</code>’
must be included in <code>name</code>; for example, a ‘<code>-``-file</code>’ option is
represented by a <code>name</code> of ‘<code>-file</code>’.</p>
<p>If a ‘<code>+</code>’ appears after <code>name</code>, the option is appended to <code>array</code>
each time it is found in the positional parameters; without the
‘<code>+</code>’ only the <em>last</em> occurrence of the option is preserved.</p>
<p>If one of these forms is used, the option takes no argument, so
parsing stops if the next positional parameter does not also begin
with ‘<code>-</code>’ (unless the <code>-E</code> option is used).</p>
</li>
<li>
<p><code>name``:</code><br />
<code>name``:-</code><br />
<code>name``::</code><br />
If one or two colons are given, the option takes an argument; with
one colon, the argument is mandatory and with two colons it is
optional. The argument is appended to the <code>array</code> after the option
itself.</p>
<p>An optional argument is put into the same array element as the
option name (note that this makes empty strings as arguments
indistinguishable). A mandatory argument is added as a separate
element unless the ‘<code>:-</code>’ form is used, in which case the argument
is put into the same element.</p>
<p>A ‘<code>+</code>’ as described above may appear between the <code>name</code> and the
first colon.</p>
</li>
</ul>
<p>In all cases, option-arguments must appear either immediately following
the option in the same positional parameter or in the next one. Even an
optional argument may appear in the next parameter, unless it begins
with a ‘<code>-</code>’. There is no special handling of ‘<code>=</code>’ as with GNU-style
argument parsers; given the <code>spec</code> ‘<code>-foo:</code>’, the positional parameter
‘<code>-``-foo=bar</code>’ is parsed as ‘<code>-``-foo</code>’ with an argument of ‘<code>=bar</code>’.</p>
<p>When the names of two options that take no arguments overlap, the
longest one wins, so that parsing for the <code>spec</code>s ‘<code>-foo -foobar</code>’ (for
example) is unambiguous. However, due to the aforementioned handling of
option-arguments, ambiguities may arise when at least one overlapping
<code>spec</code> takes an argument, as in ‘<code>-foo: -foobar</code>’. In that case, the
last matching <code>spec</code> wins.</p>
<p>The options of <code>zparseopts</code> itself cannot be stacked because, for
example, the stack ‘<code>-DEK</code>’ is indistinguishable from a <code>spec</code> for the
GNU-style long option ‘<code>-``-DEK</code>’. The options of <code>zparseopts</code> itself
are:</p>
<ul>
<li>
<p><code>-a</code> <code>array</code><br />
As described above, this names the default array in which to store
the recognised options.</p>
</li>
<li>
<p><code>-A</code> <code>assoc</code><br />
If this is given, the options and their values are also put into an
associative array with the option names as keys and the arguments
(if any) as the values.</p>
</li>
<li>
<p><code>-D</code><br />
If this option is given, all options found are removed from the
positional parameters of the calling shell or shell function, up to
but not including any not described by the <code>spec</code>s. If the first
such parameter is ‘<code>-</code>’ or ‘<code>-``-</code>’, it is removed as well. This is
similar to using the <code>shift</code> builtin.</p>
</li>
<li>
<p><code>-E</code><br />
This changes the parsing rules to <em>not</em> stop at the first string
that isn’t described by one of the <code>spec</code>s. It can be used to test
for or (if used together with <code>-D</code>) extract options and their
arguments, ignoring all other options and arguments that may be in
the positional parameters. As indicated above, parsing still stops
at the first ‘<code>-</code>’ or ‘<code>-``-</code>’ not described by a <code>spec</code>, but it is
not removed when used with <code>-D</code>.</p>
</li>
<li>
<p><code>-F</code><br />
If this option is given, <code>zparseopts</code> immediately stops at the first
option-like parameter not described by one of the <code>spec</code>s, prints an
error message, and returns status 1. Removal (<code>-D</code>) and extraction
(<code>-E</code>) are not performed, and option arrays are not updated. This
provides basic validation for the given options.</p>
<p>Note that the appearance in the positional parameters of an option
without its required argument always aborts parsing and returns an
error as described above regardless of whether this option is used.</p>
</li>
<li>
<p><code>-K</code><br />
With this option, the arrays specified with the <code>-a</code> option and with
the ‘<code>=``array</code>’ forms are kept unchanged when none of the <code>spec</code>s
for them is used. Otherwise the entire array is replaced when any of
the <code>spec</code>s is used. Individual elements of associative arrays
specified with the <code>-A</code> option are preserved by <code>-K</code>. This allows
assignment of default values to arrays before calling <code>zparseopts</code>.</p>
</li>
<li>
<p><code>-M</code><br />
This changes the assignment rules to implement a map among
equivalent option names. If any <code>spec</code> uses the ‘<code>=``array</code>’ form,
the string <code>array</code> is interpreted as the name of another <code>spec</code>,
which is used to choose where to store the values. If no other
<code>spec</code> is found, the values are stored as usual. This changes only
the way the values are stored, not the way <code>$*</code> is parsed, so
results may be</p>
</li>
</ul>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">set -- -a -bx -c y -cz baz -cend
zparseopts a=foo b:=bar c+:=bar
</code></pre>
</div>
<p>will have the effect of</p>
<div class="example">
<pre><code class="language-example">foo=(-a)
bar=(-b x -c y -c z)
</code></pre>
</div>
<p>The arguments from ‘<code>baz</code>’ on will not be used.</p>
<p>As an example for the <code>-E</code> option, consider:</p>
<div class="example">
<pre><code class="language-example">set -- -a x -b y -c z arg1 arg2
zparseopts -E -D b:=bar
</code></pre>
</div>
<p>will have the effect of</p>
<div class="example">
<pre><code class="language-example">bar=(-b y)
set -- -a x -c z arg1 arg2
</code></pre>
</div>
<p>I.e., the option <code>-b</code> and its arguments are taken from the positional
parameters and put into the array <code>bar</code>.</p>
<p>The <code>-M</code> option can be used like this:</p>
<div class="example">
<pre><code class="language-example">set -- -a -bx -c y -cz baz -cend
zparseopts -A bar -M a=foo b+: c:=b
</code></pre>
</div>
<p>to have the effect of</p>
<div class="example">
<pre><code class="language-example">foo=(-a)
bar=(-a '' -b xyz)
</code></pre>
</div>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Calendar-Function-System.html#23-calendar-function-system">23 Calendar Function System</a>
<ul>
<li><a href="Calendar-Function-System.html#231-description">23.1 Description</a></li>
<li><a href="Calendar-Function-System.html#232-file-and-date-formats">23.2 File and Date Formats</a>
<ul>
<li><a href="Calendar-Function-System.html#2321-calendar-file-format">23.2.1 Calendar File Format</a></li>
<li><a href="Calendar-Function-System.html#2322-date-format">23.2.2 Date Format</a></li>
<li><a href="Calendar-Function-System.html#2323-relative-time-format">23.2.3 Relative Time Format</a></li>
<li><a href="Calendar-Function-System.html#2324-example">23.2.4 Example</a></li>
</ul>
</li>
<li><a href="Calendar-Function-System.html#233-user-functions">23.3 User Functions</a>
<ul>
<li><a href="Calendar-Function-System.html#2331-calendar-system-functions">23.3.1 Calendar system functions</a></li>
<li><a href="Calendar-Function-System.html#2332-glob-qualifiers">23.3.2 Glob qualifiers</a></li>
</ul>
</li>
<li><a href="Calendar-Function-System.html#234-styles">23.4 Styles</a></li>
<li><a href="Calendar-Function-System.html#235-utility-functions">23.5 Utility functions</a></li>
<li><a href="Calendar-Function-System.html#236-bugs">23.6 Bugs</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Calendar-Function-System"></span>
<span id="Calendar-Function-System-1"></span></p>
<h1 id="23-calendar-function-system"><a class="header" href="#23-calendar-function-system">23 Calendar Function System</a></h1>
<p><span id="index-calendar-function-system"></span>
<span id="index-zsh_002fdatetime_002c-function-system-based-on"></span></p>
<hr />
<p><span id="Description-8"></span></p>
<h2 id="231-description"><a class="header" href="#231-description">23.1 Description</a></h2>
<p>The shell is supplied with a series of functions to replace and enhance
the traditional Unix <code>calendar</code> programme, which warns the user of
imminent or future events, details of which are stored in a text file
(typically <code>calendar</code> in the user’s home directory). The version
provided here includes a mechanism for alerting the user when an event
is due.</p>
<p>In addition functions <code>age</code>, <code>before</code> and <code>after</code> are provided that can
be used in a glob qualifier; they allow files to be selected based on
their modification times.</p>
<p>The format of the <code>calendar</code> file and the dates used there in and in the
<code>age</code> function are described first, then the functions that can be
called to examine and modify the <code>calendar</code> file.</p>
<p>The functions here depend on the availability of the <code>zsh/datetime</code>
module which is usually installed with the shell. The library function
<code>strptime()</code> must be available; it is present on most recent operating
systems.</p>
<hr />
<p><span id="Calendar-File-and-Date-Formats"></span>
<span id="File-and-Date-Formats"></span></p>
<h2 id="232-file-and-date-formats"><a class="header" href="#232-file-and-date-formats">23.2 File and Date Formats</a></h2>
<hr />
<p><span id="Calendar-File-Format"></span></p>
<h3 id="2321-calendar-file-format"><a class="header" href="#2321-calendar-file-format">23.2.1 Calendar File Format</a></h3>
<p>The calendar file is by default <code>~/calendar</code>. This can be configured by
the <code>calendar-file</code> style, see <a href="Calendar-Function-System.html#Calendar-Styles">Styles</a>. The basic
format consists of a series of separate lines, with no indentation, each
including a date and time specification followed by a description of the
event.</p>
<p>Various enhancements to this format are supported, based on the syntax
of Emacs calendar mode. An indented line indicates a continuation line
that continues the description of the event from the preceding line
(note the date may not be continued in this way). An initial ampersand
(<code>&amp;</code>) is ignored for compatibility.</p>
<p>An indented line on which the first non-whitespace character is <code>#</code> is
not displayed with the calendar entry, but is still scanned for
information. This can be used to hide information useful to the calendar
system but not to the user, such as the unique identifier used by
<code>calendar_add</code>.</p>
<p>The Emacs extension that a date with no description may refer to a
number of succeeding events at different times is not supported.</p>
<p>Unless the <code>done-file</code> style has been altered, any events which have
been processed are appended to the file with the same name as the
calendar file with the suffix <code>.done</code>, hence <code>~/calendar.done</code> by
default.</p>
<p>An example is shown below.</p>
<hr />
<p><span id="Date-Format"></span></p>
<h3 id="2322-date-format"><a class="header" href="#2322-date-format">23.2.2 Date Format</a></h3>
<p>The format of the date and time is designed to allow flexibility without
admitting ambiguity. (The words ‘date’ and ‘time’ are both used in the
documentation below; except where specifically noted this implies a
string that may include both a date and a time specification.) Note that
there is no localization support; month and day names must be in English
and separator characters are fixed. Matching is case insensitive, and
only the first three letters of the names are significant, although as a
special case a form beginning &quot;month&quot; does not match &quot;Monday&quot;.
Furthermore, time zones are not handled; all times are assumed to be
local.</p>
<p>It is recommended that, rather than exploring the intricacies of the
system, users find a date format that is natural to them and stick to
it. This will avoid unexpected effects. Various key facts should be
noted.</p>
<ul>
<li>In particular, note the confusion between <code>month``/``day``/``year</code>
and <code>day``/``month``/``year</code> when the month is numeric; these
formats should be avoided if at all possible. Many alternatives are
available.</li>
<li>The year must be given in full to avoid confusion, and only years
from 1900 to 2099 inclusive are matched.</li>
</ul>
<p>The following give some obvious examples; users finding here a format
they like and not subject to vagaries of style may skip the full
description. As dates and times are matched separately (even though the
time may be embedded in the date), any date format may be mixed with any
format for the time of day provide the separators are clear (whitespace,
colons, commas).</p>
<div class="example">
<pre><code class="language-example">2007/04/03 13:13
2007/04/03:13:13
2007/04/03 1:13 pm
3rd April 2007, 13:13
April 3rd 2007 1:13 p.m.
Apr 3, 2007 13:13
Tue Apr 03 13:13:00 2007
13:13 2007/apr/3
</code></pre>
</div>
<p>More detailed rules follow.</p>
<p>Times are parsed and extracted before dates. They must use colons to
separate hours and minutes, though a dot is allowed before seconds if
they are present. This limits time formats to the following:</p>
<ul>
<li><code>HH``:``MM</code>[<code>:``SS</code>[<code>.``FFFFF</code>]] [<code>am</code>|<code>pm</code>|<code>a.m.</code>|<code>p.m.</code>]</li>
<li><code>HH``:``MM``.``SS</code>[<code>.``FFFFF</code>] [<code>am</code>|<code>pm</code>|<code>a.m.</code>|<code>p.m.</code>]</li>
</ul>
<p>Here, square brackets indicate optional elements, possibly with
alternatives. Fractions of a second are recognised but ignored. For
absolute times (the normal format require by the <code>calendar</code> file and the
<code>age</code>, <code>before</code> and <code>after</code> functions) a date is mandatory but a time of
day is not; the time returned is at the start of the date. One variation
is allowed: if <code>a.m.</code> or <code>p.m.</code> or one of their variants is present, an
hour without a minute is allowed, e.g. <code>3 p.m.</code>.</p>
<p>Time zones are not handled, though if one is matched following a time
specification it will be removed to allow a surrounding date to be
parsed. This only happens if the format of the timezone is not too
unusual. The following are examples of forms that are understood:</p>
<div class="example">
<pre><code class="language-example">+0100
GMT
GMT-7
CET+1CDT
</code></pre>
</div>
<p>Any part of the timezone that is not numeric must have exactly three
capital letters in the name.</p>
<p>Dates suffer from the ambiguity between <code>DD``/``MM``/``YYYY</code> and
<code>MM``/``DD``/``YYYY</code>. It is recommended this form is avoided with purely
numeric dates, but use of ordinals, eg. <code>3rd/04/2007</code>, will resolve the
ambiguity as the ordinal is always parsed as the day of the month. Years
must be four digits (and the first two must be <code>19</code> or <code>20</code>); <code>03/04/08</code>
is not recognised. Other numbers may have leading zeroes, but they are
not required. The following are handled:</p>
<ul>
<li><code>YYYY``/``MM``/``DD</code></li>
<li><code>YYYY``-``MM``-``DD</code></li>
<li><code>YYYY``/``MNM``/``DD</code></li>
<li><code>YYYY``-``MNM``-``DD</code></li>
<li><code>DD</code>[<code>th</code>|<code>st</code>|<code>rd</code>] <code>MNM</code>[<code>,</code>] [ <code>YYYY</code> ]</li>
<li><code>MNM</code> <code>DD</code>[<code>th</code>|<code>st</code>|<code>rd</code>][<code>,</code>] [ <code>YYYY</code> ]</li>
<li><code>DD</code>[<code>th</code>|<code>st</code>|<code>rd</code>]<code>/``MM</code>[<code>,</code>] <code>YYYY</code></li>
<li><code>DD</code>[<code>th</code>|<code>st</code>|<code>rd</code>]<code>/``MM``/``YYYY</code></li>
<li><code>MM``/``DD</code>[<code>th</code>|<code>st</code>|<code>rd</code>][<code>,</code>] <code>YYYY</code></li>
<li><code>MM``/``DD</code>[<code>th</code>|<code>st</code>|<code>rd</code>]<code>/``YYYY</code></li>
</ul>
<p>Here, <code>MNM</code> is at least the first three letters of a month name, matched
case-insensitively. The remainder of the month name may appear but its
contents are irrelevant, so janissary, febrile, martial, apricot, maybe,
junta, etc. are happily handled.</p>
<p>Where the year is shown as optional, the current year is assumed. There
are only two such cases, the form <code>Jun 20</code> or <code>14 September</code> (the only
two commonly occurring forms, apart from a &quot;the&quot; in some forms of
English, which isn’t currently supported). Such dates will of course
become ambiguous in the future, so should ideally be avoided.</p>
<p>Times may follow dates with a colon, e.g. <code>1965/07/12:09:45</code>; this is in
order to provide a format with no whitespace. A comma and whitespace are
allowed, e.g. <code>1965/07/12, 09:45</code>. Currently the order of these
separators is not checked, so illogical formats such as <code>1965/07/12, : ,09:45</code> will also be matched. For simplicity such variations are not
shown in the list above. Otherwise, a time is only recognised as being
associated with a date if there is only whitespace in between, or if the
time was embedded in the date.</p>
<p>Days of the week are not normally scanned, but will be ignored if they
occur at the start of the date pattern only. However, in contexts where
it is useful to specify dates relative to today, days of the week with
no other date specification may be given. The day is assumed to be
either today or within the past week. Likewise, the words <code>yesterday</code>,
<code>today</code> and <code>tomorrow</code> are handled. All matches are case-insensitive.
Hence if today is Monday, then <code>Sunday</code> is equivalent to <code>yesterday</code>,
<code>Monday</code> is equivalent to <code>today</code>, but <code>Tuesday</code> gives a date six days
ago. This is not generally useful within the calendar file. Dates in
this format may be combined with a time specification; for example
<code>Tomorrow, 8 p.m.</code>.</p>
<p>For example, the standard date format:</p>
<div class="example">
<pre><code class="language-example">Fri Aug 18 17:00:48 BST 2006
</code></pre>
</div>
<p>is handled by matching <code>HH``:``MM``:``SS</code> and removing it together with
the matched (but unused) time zone. This leaves the following:</p>
<div class="example">
<pre><code class="language-example">Fri Aug 18 2006
</code></pre>
</div>
<p><code>Fri</code> is ignored and the rest is matched according to the standard
rules.</p>
<hr />
<p><span id="Relative-Time-Format"></span></p>
<h3 id="2323-relative-time-format"><a class="header" href="#2323-relative-time-format">23.2.3 Relative Time Format</a></h3>
<p>In certain places relative times are handled. Here, a date is not
allowed; instead a combination of various supported periods are allowed,
together with an optional time. The periods must be in order from most
to least significant.</p>
<p>In some cases, a more accurate calculation is possible when there is an
anchor date: offsets of months or years pick the correct day, rather
than being rounded, and it is possible to pick a particular day in a
month as ‘(1st Friday)’, etc., as described in more detail below.</p>
<p>Anchors are available in the following cases. If one or two times are
passed to the function <code>calendar</code>, the start time acts an anchor for the
end time when the end time is relative (even if the start time is
implicit). When examining calendar files, the scheduled event being
examined anchors the warning time when it is given explicitly by means
of the <code>WARN</code> keyword; likewise, the scheduled event anchors a
repetition period when given by the <code>RPT</code> keyword, so that
specifications such as <code>RPT 2 months, 3rd Thursday</code> are handled
properly. Finally, the <code>-R</code> argument to <code>calendar_scandate</code> directly
provides an anchor for relative calculations.</p>
<p>The periods handled, with possible abbreviations are:</p>
<ul>
<li>
<p>Years<br />
<code>years</code>, <code>yrs</code>, <code>ys</code>, <code>year</code>, <code>yr</code>, <code>y</code>, <code>yearly</code>. A year is 365.25
days unless there is an anchor.</p>
</li>
<li>
<p>Months<br />
<code>months</code>, <code>mons</code>, <code>mnths</code>, <code>mths</code>, <code>month</code>, <code>mon</code>, <code>mnth</code>, <code>mth</code>,
<code>monthly</code>. Note that <code>m</code>, <code>ms</code>, <code>mn</code>, <code>mns</code> are ambiguous and are
<em>not</em> handled. A month is a period of 30 days rather than a calendar
month unless there is an anchor.</p>
</li>
<li>
<p>Weeks<br />
<code>weeks</code>, <code>wks</code>, <code>ws</code>, <code>week</code>, <code>wk</code>, <code>w</code>, <code>weekly</code></p>
</li>
<li>
<p>Days<br />
<code>days</code>, <code>dys</code>, <code>ds</code>, <code>day</code>, <code>dy</code>, <code>d</code>, <code>daily</code></p>
</li>
<li>
<p>Hours<br />
<code>hours</code>, <code>hrs</code>, <code>hs</code>, <code>hour</code>, <code>hr</code>, <code>h</code>, <code>hourly</code></p>
</li>
<li>
<p>Minutes<br />
<code>minutes</code>, <code>mins</code>, <code>minute</code>, <code>min</code>, but <em>not</em> <code>m</code>, <code>ms</code>, <code>mn</code> or
<code>mns</code></p>
</li>
<li>
<p>Seconds<br />
<code>seconds</code>, <code>secs</code>, <code>ss</code>, <code>second</code>, <code>sec</code>, <code>s</code></p>
</li>
</ul>
<p>Spaces between the numbers are optional, but are required between items,
although a comma may be used (with or without spaces).</p>
<p>The forms <code>yearly</code> to <code>hourly</code> allow the number to be omitted; it is
assumed to be 1. For example, <code>1 d</code> and <code>daily</code> are equivalent. Note
that using those forms with plurals is confusing; <code>2 yearly</code> is the same
as <code>2 years</code>, <em>not</em> twice yearly, so it is recommended they only be used
without numbers.</p>
<p>When an anchor time is present, there is an extension to handle regular
events in the form of the <code>n</code>th <code>some</code>day of the month. Such a
specification must occur immediately after any year and month
specification, but before any time of day, and must be in the form
<code>n</code>(<code>th</code>|<code>st</code>|<code>rd</code>) <code>day</code>, for example <code>1st Tuesday</code> or <code>3rd Monday</code>. As
in other places, days are matched case insensitively, must be in
English, and only the first three letters are significant except that a
form beginning ‘month’ does not match ‘Monday’. No attempt is made to
sanitize the resulting date; attempts to squeeze too many occurrences
into a month will push the day into the next month (but in the obvious
fashion, retaining the correct day of the week).</p>
<p>Here are some examples:</p>
<div class="example">
<pre><code class="language-example">30 years 3 months 4 days 3:42:41
14 days 5 hours
Monthly, 3rd Thursday
4d,10hr
</code></pre>
</div>
<hr />
<p><span id="Example-2"></span></p>
<h3 id="2324-example"><a class="header" href="#2324-example">23.2.4 Example</a></h3>
<p>Here is an example calendar file. It uses a consistent date format, as
recommended above.</p>
<div class="example">
<pre><code class="language-example">Feb 1, 2006 14:30 Pointless bureaucratic meeting
Mar 27, 2006 11:00 Mutual recrimination and finger pointing
Bring water pistol and waterproofs
Mar 31, 2006 14:00 Very serious managerial pontification
# UID 12C7878A9A50
Apr 10, 2006 13:30 Even more pointless blame assignment exercise WARN 30 mins
May 18, 2006 16:00 Regular moaning session RPT monthly, 3rd Thursday
</code></pre>
</div>
<p>The second entry has a continuation line. The third entry has a
continuation line that will not be shown when the entry is displayed,
but the unique identifier will be used by the <code>calendar_add</code> function
when updating the event. The fourth entry will produce a warning 30
minutes before the event (to allow you to equip yourself appropriately).
The fifth entry repeats after a month on the 3rd Thursday, i.e. June 15,
2006, at the same time.</p>
<hr />
<p><span id="Calendar-System-User-Functions"></span>
<span id="User-Functions"></span></p>
<h2 id="233-user-functions"><a class="header" href="#233-user-functions">23.3 User Functions</a></h2>
<p>This section describes functions that are designed to be called directly
by the user. The first part describes those functions associated with
the user’s calendar; the second part describes the use in glob
qualifiers.</p>
<hr />
<p><span id="Calendar-system-functions"></span></p>
<h3 id="2331-calendar-system-functions"><a class="header" href="#2331-calendar-system-functions">23.3.1 Calendar system functions</a></h3>
<p><span id="index-calendar"></span></p>
<p><code>calendar </code>[ <code>-abdDsv</code> ] [ <code>-C</code> <code>calfile</code> ] [ <code>-n</code> <code>num</code> ] [
<code>-S</code> <code>showprog</code> ]</p>
<p><code>         </code>[ [ <code>start</code> ] <code>end</code> ]</p>
<p><code>calendar -r</code> [ <code>-abdDrsv</code> ] [ <code>-C</code> <code>calfile</code> ] [ <code>-n</code> <code>num</code> ] [
<code>-S</code> <code>showprog</code> ]</p>
<p><code>         </code>[ <code>start</code> ]</p>
<p>Show events in the calendar.</p>
<p>With no arguments, show events from the start of today until the end of
the next working day after today. In other words, if today is Friday,
Saturday, or Sunday, show up to the end of the following Monday,
otherwise show today and tomorrow.</p>
<p>If <code>end</code> is given, show events from the start of today up to the time
and date given, which is in the format described in the previous
section. Note that if this is a date the time is assumed to be midnight
at the start of the date, so that effectively this shows all events
before the given date.</p>
<p><code>end</code> may start with a <code>+</code>, in which case the remainder of the
specification is a relative time format as described in the previous
section indicating the range of time from the start time that is to be
included.</p>
<p>If <code>start</code> is also given, show events starting from that time and date.
The word <code>now</code> can be used to indicate the current time.</p>
<p>To implement an alert when events are due, include <code>calendar -s</code> in your
<code>~/.zshrc</code> file.</p>
<p>Options:</p>
<ul>
<li>
<p><code>-a</code><br />
Show all items in the calendar, regardless of the <code>start</code> and <code>end</code>.</p>
</li>
<li>
<p><code>-b</code><br />
Brief: don’t display continuation lines (i.e. indented lines
following the line with the date/time), just the first line.</p>
</li>
<li>
<p><code>-B</code> <code>lines</code><br />
Brief: display at most the first <code>lines</code> lines of the calendar
entry. ‘<code>-B 1</code>’ is equivalent to ‘<code>-b</code>’.</p>
</li>
<li>
<p><code>-C</code> <code>calfile</code><br />
Explicitly specify a calendar file instead of the value of the
<code>calendar-file</code> style or the default <code>~/calendar</code>.</p>
</li>
<li>
<p><code>-d</code><br />
Move any events that have passed from the calendar file to the
&quot;done&quot; file, as given by the <code>done-file</code> style or the default which
is the calendar file with <code>.done</code> appended. This option is implied
by the <code>-s</code> option.</p>
</li>
<li>
<p><code>-D</code><br />
Turns off the option <code>-d</code>, even if the <code>-s</code> option is also present.</p>
</li>
<li>
<p><code>-n</code> <code>num</code>, <code>-``num</code><br />
Show at least <code>num</code> events, if present in the calendar file,
regardless of the <code>start</code> and <code>end</code>.</p>
</li>
<li>
<p><code>-r</code><br />
Show all the remaining options in the calendar, ignoring the given
<code>end</code> time. The <code>start</code> time is respected; any argument given is
treated as a <code>start</code> time.</p>
</li>
<li>
<p><code>-s</code><br />
Use the shell’s <code>sched</code> command to schedule a timed event that will
warn the user when an event is due. Note that the <code>sched</code> command
only runs if the shell is at an interactive prompt; a foreground
task blocks the scheduled task from running until it is finished.</p>
<p>The timed event usually runs the programme <code>calendar_show</code> to show
the event, as described in <a href="Calendar-Function-System.html#Calendar-Utility-Functions">Utility
functions</a>.</p>
<p>By default, a warning of the event is shown five minutes before it
is due. The warning period can be configured by the style
<code>warn-time</code> or for a single calendar entry by including <code>WARN</code>
<code>reltime</code> in the first line of the entry, where <code>reltime</code> is one of
the usual relative time formats.</p>
<p>A repeated event may be indicated by including <code>RPT</code> <code>reldate</code> in
the first line of the entry. After the scheduled event has been
displayed it will be re-entered into the calendar file at a time
<code>reldate</code> after the existing event. Note that this is currently the
only use made of the repeat count, so that it is not possible to
query the schedule for a recurrence of an event in the calendar
until the previous event has passed.</p>
<p>If <code>RPT</code> is used, it is also possible to specify that certain
recurrences of an event are rescheduled or cancelled. This is done
with the <code>OCCURRENCE</code> keyword, followed by whitespace and the date
and time of the occurrence in the regular sequence, followed by
whitespace and either the date and time of the rescheduled event or
the exact string <code>CANCELLED</code>. In this case the date and time must be
in exactly the &quot;date with local time&quot; format used by the
<code>text/calendar</code> MIME type (RFC 2445),
<code>&lt;YYYY&gt;&lt;MM&gt;&lt;DD&gt;``T``&lt;hh&gt;&lt;mm&gt;&lt;ss&gt;</code> (note the presence of the literal
character <code>T</code>). The first word (the regular recurrence) may be
something other than a proper date/time to indicate that the event
is additional to the normal sequence; a convention that retains the
formatting appearance is <code>XXXXXXXXTXXXXXX</code>.</p>
<p>Furthermore, it is useful to record the next regular recurrence (as
then the displayed date may be for a rescheduled event so cannot be
used for calculating the regular sequence). This is specified by
<code>RECURRENCE</code> and a time or date in the same format. <code>calendar_add</code>
adds such an indication when it encounters a recurring event that
does not include one, based on the headline date/time.</p>
<p>If <code>calendar_add</code> is used to update occurrences the <code>UID</code> keyword
described there should be present in both the existing entry and the
added occurrence in order to identify recurring event sequences.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">Thu May 6, 2010 11:00 Informal chat RPT 1 week
# RECURRENCE 20100506T110000
# OCCURRENCE 20100513T110000 20100513T120000
# OCCURRENCE 20100520T110000 CANCELLED
</code></pre>
</div>
<p>The event that occurs at 11:00 on 13th May 2010 is rescheduled an
hour later. The event that occurs a week later is cancelled. The
occurrences are given on a continuation line starting with a <code>#</code>
character so will not usually be displayed as part of the event. As
elsewhere, no account of time zones is taken with the times. After
the next event occurs the headline date/time will be ‘<code>Thu May 13, 2010 12:00</code>’ while the <code>RECURRENCE</code> date/time will be
‘<code>20100513T110000</code>’ (note that cancelled and moved events are not
taken account of in the <code>RECURRENCE</code>, which records what the next
regular recurrence is, but they are accounted for in the headline
date/time).</p>
<p>It is safe to run <code>calendar -s</code> to reschedule an existing event (if
the calendar file has changed, for example), and also to have it
running in multiples instances of the shell since the calendar file
is locked when in use.</p>
<p>By default, expired events are moved to the &quot;done&quot; file; see the
<code>-d</code> option. Use <code>-D</code> to prevent this.</p>
</li>
<li>
<p><code>-S</code> <code>showprog</code><br />
Explicitly specify a programme to be used for showing events instead
of the value of the <code>show-prog</code> style or the default
<code>calendar_show</code>.</p>
</li>
<li>
<p><code>-v</code><br />
Verbose: show more information about stages of processing. This is
useful for confirming that the function has successfully parsed the
dates in the calendar file.</p>
</li>
</ul>
<p><span id="index-calendar_005fadd"></span></p>
<p><code>calendar_add</code> [ <code>-BL</code> ] <code>event</code> ...</p>
<p>Adds a single event to the calendar in the appropriate location. The
event can contain multiple lines, as described in <a href="Calendar-Function-System.html#Calendar-File-and-Date-Formats">File and Date
Formats</a>. Using this function ensures
that the calendar file is sorted in date and time order. It also makes
special arrangements for locking the file while it is altered. The old
calendar is left in a file with the suffix <code>.old</code>.</p>
<p>The option <code>-B</code> indicates that backing up the calendar file will be
handled by the caller and should not be performed by <code>calendar_add</code>. The
option <code>-L</code> indicates that <code>calendar_add</code> does not need to lock the
calendar file as it is already locked. These options will not usually be
needed by users.</p>
<p>If the style <code>reformat-date</code> is true, the date and time of the new entry
will be rewritten into the standard date format: see the descriptions of
this style and the style <code>date-format</code>.</p>
<p>The function can use a unique identifier stored with each event to
ensure that updates to existing events are treated correctly. The entry
should contain the word <code>UID</code>, followed by whitespace, followed by a
word consisting entirely of hexadecimal digits of arbitrary length (all
digits are significant, including leading zeroes). As the UID is not
directly useful to the user, it is convenient to hide it on an indented
continuation line starting with a <code>#</code>, for example:</p>
<div class="example">
<pre><code class="language-example">Aug 31, 2007 09:30 Celebrate the end of the holidays
# UID 045B78A0
</code></pre>
</div>
<p>The second line will not be shown by the <code>calendar</code> function.</p>
<p>It is possible to specify the <code>RPT</code> keyword followed by <code>CANCELLED</code>
instead of a relative time. This causes any matched event or series of
events to be cancelled (the original event does not have to be marked as
recurring in order to be cancelled by this method). A <code>UID</code> is required
in order to match an existing event in the calendar.</p>
<p><code>calendar_add</code> will attempt to manage recurrences and occurrences of
repeating events as described for event scheduling by <code>calendar -s</code>
above. To reschedule or cancel a single event <code>calendar_add</code> should be
called with an entry that includes the correct <code>UID</code> but does <em>not</em>
include the <code>RPT</code> keyword as this is taken to mean the entry applies to
a series of repeating events and hence replaces all existing
information. Each rescheduled or cancelled occurrence must have an
<code>OCCURRENCE</code> keyword in the entry passed to <code>calendar_add</code> which will be
merged into the calendar file. Any existing reference to the occurrence
is replaced. An occurrence that does not refer to a valid existing event
is added as a one-off occurrence to the same calendar entry.</p>
<p><span id="index-calendar_005fedit"></span></p>
<p><code>calendar_edit</code></p>
<p>This calls the user’s editor to edit the calendar file. If there are
arguments, they are taken as the editor to use (the file name is
appended to the commands); otherwise, the editor is given by the
variable <code>VISUAL</code>, if set, else the variable <code>EDITOR</code>.</p>
<p>If the calendar scheduler was running, then after editing the file
<code>calendar -s</code> is called to update it.</p>
<p>This function locks out the calendar system during the edit. Hence it
should be used to edit the calendar file if there is any possibility of
a calendar event occurring meanwhile. Note this can lead to another
shell with calendar functions enabled hanging waiting for a lock, so it
is necessary to quit the editor as soon as possible.</p>
<p><span id="index-calendar_005fparse"></span></p>
<p><code>calendar_parse</code> <code>calendar-entry</code></p>
<p>This is the internal function that analyses the parts of a calendar
entry, which is passed as the only argument. The function returns status
1 if the argument could not be parsed as a calendar entry and status 2
if the wrong number of arguments were passed; it also sets the parameter
<code>reply</code> to an empty associative array. Otherwise, it returns status 0
and sets elements of the associative array <code>reply</code> as follows:</p>
<ul>
<li>
<p><code>time</code><br />
The time as a string of digits in the same units as <code>$EPOCHSECONDS</code></p>
</li>
<li>
<p><code>schedtime</code><br />
The regularly scheduled time. This may differ from the actual event
time <code>time</code> if this is a recurring event and the next occurrence has
been rescheduled. Then <code>time</code> gives the actual time and <code>schedtime</code>
the time of the regular recurrence before modification.</p>
</li>
<li>
<p><code>text1</code><br />
The text from the line not including the date and time of the event,
but including any <code>WARN</code> or <code>RPT</code> keywords and values.</p>
</li>
<li>
<p><code>warntime</code><br />
Any warning time given by the <code>WARN</code> keyword as a string of digits
containing the time at which to warn in the same units as
<code>$EPOCHSECONDS</code>. (Note this is an absolute time, not the relative
time passed down.) Not set no <code>WARN</code> keyword and value were matched.</p>
</li>
<li>
<p><code>warnstr</code><br />
The raw string matched after the <code>WARN</code> keyword, else unset.</p>
</li>
<li>
<p><code>rpttime</code><br />
Any recurrence time given by the <code>RPT</code> keyword as a string of digits
containing the time of the recurrence in the same units as
<code>$EPOCHSECONDS</code>. (Note this is an absolute time.) Not set if no
<code>RPT</code> keyword and value were matched.</p>
</li>
<li>
<p><code>schedrpttime</code><br />
The next regularly scheduled occurrence of a recurring event before
modification. This may differ from <code>rpttime</code>, which is the actual
time of the event that may have been rescheduled from the regular
time.</p>
</li>
<li>
<p><code>rptstr</code><br />
The raw string matched after the <code>RPT</code> keyword, else unset.</p>
</li>
<li>
<p><code>text2</code><br />
The text from the line after removal of the date and any keywords
and values.</p>
</li>
</ul>
<p><span id="index-calendar_005fshowdate"></span></p>
<p><code>calendar_showdate</code> [ <code>-r</code> ] [ <code>-f</code> <code>fmt</code> ] <code>date-spec</code> ...</p>
<p>The given <code>date-spec</code> is interpreted and the corresponding date and time
printed. If the initial <code>date-spec</code> begins with a <code>+</code> or <code>-</code> it is
treated as relative to the current time; <code>date-spec</code>s after the first
are treated as relative to the date calculated so far and a leading <code>+</code>
is optional in that case. This allows one to use the system as a date
calculator. For example, <code>calendar_showdate ’+1 month, 1st Friday’</code>
shows the date of the first Friday of next month.</p>
<p>With the option <code>-r</code> nothing is printed but the value of the date and
time in seconds since the epoch is stored in the parameter <code>REPLY</code>.</p>
<p>With the option <code>-f</code> <code>fmt</code> the given date/time conversion format is
passed to <code>strftime</code>; see notes on the <code>date-format</code> style below.</p>
<p>In order to avoid ambiguity with negative relative date specifications,
options must occur in separate words; in other words, <code>-r</code> and <code>-f</code>
should not be combined in the same word.</p>
<p><span id="index-calendar_005fsort"></span></p>
<p><code>calendar_sort</code></p>
<p>Sorts the calendar file into date and time order. The old calendar is
left in a file with the suffix <code>.old</code>.</p>
<hr />
<p><span id="Glob-qualifiers"></span></p>
<h3 id="2332-glob-qualifiers"><a class="header" href="#2332-glob-qualifiers">23.3.2 Glob qualifiers</a></h3>
<ul>
<li>
<p><code>age</code><br />
<span id="index-age"></span></p>
<p>The function <code>age</code> can be autoloaded and use separately from the
calendar system, although it uses the function <code>calendar_scandate</code>
for date formatting. It requires the <code>zsh/stat</code> builtin, but uses
only the builtin <code>zstat</code>.</p>
<p><code>age</code> selects files having a given modification time for use as a
glob qualifier. The format of the date is the same as that
understood by the calendar system, described in <a href="Calendar-Function-System.html#Calendar-File-and-Date-Formats">File and Date
Formats</a>.</p>
<p>The function can take one or two arguments, which can be supplied
either directly as command or arguments, or separately as shell
parameters.</p>
<div class="example">
<pre><code class="language-example">print *(e:age 2006/10/04 2006/10/09:)
</code></pre>
</div>
<p>The example above matches all files modified between the start of
those dates. The second argument may alternatively be a relative
time introduced by a <code>+</code>:</p>
<div class="example">
<pre><code class="language-example">print *(e:age 2006/10/04 +5d:)
</code></pre>
</div>
<p>The example above is equivalent to the previous example.</p>
<p>In addition to the special use of days of the week, <code>today</code> and
<code>yesterday</code>, times with no date may be specified; these apply to
today. Obviously such uses become problematic around midnight.</p>
<div class="example">
<pre><code class="language-example">print *(e-age 12:00 13:30-)
</code></pre>
</div>
<p>The example above shows files modified between 12:00 and 13:00
today.</p>
<div class="example">
<pre><code class="language-example">print *(e:age 2006/10/04:)
</code></pre>
</div>
<p>The example above matches all files modified on that date. If the
second argument is omitted it is taken to be exactly 24 hours after
the first argument (even if the first argument contains a time).</p>
<div class="example">
<pre><code class="language-example">print *(e-age 2006/10/04:10:15 2006/10/04:10:45-)
</code></pre>
</div>
<p>The example above supplies times. Note that whitespace within the
time and date specification must be quoted to ensure <code>age</code> receives
the correct arguments, hence the use of the additional colon to
separate the date and time.</p>
<div class="example">
<pre><code class="language-example">AGEREF=2006/10/04:10:15
AGEREF2=2006/10/04:10:45
print *(+age)
</code></pre>
</div>
<p>This shows the same example before using another form of argument
passing. The dates and times in the parameters <code>AGEREF</code> and
<code>AGEREF2</code> stay in effect until unset, but will be overridden if any
argument is passed as an explicit argument to age. Any explicit
argument causes both parameters to be ignored.</p>
<p>Instead of an explicit date and time, it’s possible to use the
modification time of a file as the date and time for either argument
by introducing the file name with a colon:</p>
<div class="example">
<pre><code class="language-example">print *(e-age :file1-)
</code></pre>
</div>
<p>matches all files created on the same day (24 hours starting from
midnight) as <code>file1</code>.</p>
<div class="example">
<pre><code class="language-example">print *(e-age :file1 :file2-)
</code></pre>
</div>
<p>matches all files modified no earlier than <code>file1</code> and no later than
<code>file2</code>; precision here is to the nearest second.</p>
</li>
<li>
<p><code>after</code><br />
<code>before</code><br />
<span id="index-after"></span> <span id="index-before"></span></p>
<p>The functions <code>after</code> and <code>before</code> are simpler versions of <code>age</code>
that take just one argument. The argument is parsed similarly to an
argument of <code>age</code>; if it is not given the variable <code>AGEREF</code> is
consulted. As the names of the functions suggest, a file matches if
its modification time is after or before the time and date
specified. If a time only is given the date is today.</p>
<p>The two following examples are therefore equivalent:</p>
<div class="example">
<pre><code class="language-example">print *(e-after 12:00-)
print *(e-after today:12:00-)
</code></pre>
</div>
</li>
</ul>
<hr />
<p><span id="Calendar-Styles"></span> <span id="Styles-1"></span></p>
<h2 id="234-styles"><a class="header" href="#234-styles">23.4 Styles</a></h2>
<p>The zsh style mechanism using the <code>zstyle</code> command is describe in <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The
zsh/zutil Module</a>. This is
the same mechanism used in the completion system.</p>
<p>The styles below are all examined in the context
<code>:datetime:``function``:</code>, for example <code>:datetime:calendar:</code>.</p>
<p><span id="index-calendar_002dfile"></span></p>
<p><code>calendar-file</code></p>
<p>The location of the main calendar. The default is <code>~/calendar</code>.</p>
<p><span id="index-date_002dformat"></span></p>
<p><code>date-format</code></p>
<p>A <code>strftime</code> format string (see man page strftime(3)) with the zsh
extensions providing various numbers with no leading zero or space if
the number is a single digit as described for the <code>%D{``string``}</code>
prompt format in <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>.</p>
<p>This is used for outputting dates in <code>calendar</code>, both to support the
<code>-v</code> option and when adding recurring events back to the calendar file,
and in <code>calendar_showdate</code> as the final output format.</p>
<p>If the style is not set, the default used is similar the standard system
format as output by the <code>date</code> command (also known as ‘ctime format’):
‘<code>%a %b %d %H:%M:%S %Z %Y</code>’.</p>
<p><span id="index-done_002dfile"></span></p>
<p><code>done-file</code></p>
<p>The location of the file to which events which have passed are appended.
The default is the calendar file location with the suffix <code>.done</code>. The
style may be set to an empty string in which case a &quot;done&quot; file will not
be maintained.</p>
<p><span id="index-reformat_002ddate"></span></p>
<p><code>reformat-date</code></p>
<p>Boolean, used by <code>calendar_add</code>. If it is true, the date and time of new
entries added to the calendar will be reformatted to the format given by
the style <code>date-format</code> or its default. Only the date and time of the
event itself is reformatted; any subsidiary dates and times such as
those associated with repeat and warning times are left alone.</p>
<p><span id="index-show_002dprog"></span></p>
<p><code>show-prog</code></p>
<p>The programme run by <code>calendar</code> for showing events. It will be passed
the start time and stop time of the events requested in seconds since
the epoch followed by the event text. Note that <code>calendar -s</code> uses a
start time and stop time equal to one another to indicate alerts for
specific events.</p>
<p>The default is the function <code>calendar_show</code>.</p>
<p><span id="index-warn_002dtime"></span></p>
<p><code>warn-time</code></p>
<p>The time before an event at which a warning will be displayed, if the
first line of the event does not include the text <code>EVENT</code> <code>reltime</code>. The
default is 5 minutes.</p>
<hr />
<p><span id="Calendar-Utility-Functions"></span>
<span id="Utility-functions"></span></p>
<h2 id="235-utility-functions"><a class="header" href="#235-utility-functions">23.5 Utility functions</a></h2>
<p><span id="index-calendar_005flockfiles"></span></p>
<p><code>calendar_lockfiles</code></p>
<p>Attempt to lock the files given in the argument. To prevent problems
with network file locking this is done in an ad hoc fashion by
attempting to create a symbolic link to the file with the name
<code>file``.lockfile</code>. No other system level functions are used for locking,
i.e. the file can be accessed and modified by any utility that does not
use this mechanism. In particular, the user is not prevented from
editing the calendar file at the same time unless <code>calendar_edit</code> is
used.</p>
<p>Three attempts are made to lock the file before giving up. If the module
<code>zsh/zselect</code> is available, the times of the attempts are jittered so
that multiple instances of the calling function are unlikely to retry at
the same time.</p>
<p>The files locked are appended to the array <code>lockfiles</code>, which should be
local to the caller.</p>
<p>If all files were successfully locked, status zero is returned, else
status one.</p>
<p>This function may be used as a general file locking function, although
this will only work if only this mechanism is used to lock files.</p>
<p><span id="index-calendar_005fread"></span></p>
<p><code>calendar_read</code></p>
<p>This is a backend used by various other functions to parse the calendar
file, which is passed as the only argument. The array <code>calendar_entries</code>
is set to the list of events in the file; no pruning is done except that
ampersands are removed from the start of the line. Each entry may
contain multiple lines.</p>
<p><span id="index-calendar_005fscandate"></span></p>
<p><code>calendar_scandate</code></p>
<p>This is a generic function to parse dates and times that may be used
separately from the calendar system. The argument is a date or time
specification as described in <a href="Calendar-Function-System.html#Calendar-File-and-Date-Formats">File and Date
Formats</a>. The parameter <code>REPLY</code> is set
to the number of seconds since the epoch corresponding to that date or
time. By default, the date and time may occur anywhere within the given
argument.</p>
<p>Returns status zero if the date and time were successfully parsed, else
one.</p>
<p>Options:</p>
<ul>
<li>
<p><code>-a</code><br />
The date and time are anchored to the start of the argument; they
will not be matched if there is preceding text.</p>
</li>
<li>
<p><code>-A</code><br />
The date and time are anchored to both the start and end of the
argument; they will not be matched if the is any other text in the
argument.</p>
</li>
<li>
<p><code>-d</code><br />
Enable additional debugging output.</p>
</li>
<li>
<p><code>-m</code><br />
Minus. When <code>-R</code> <code>anchor_time</code> is also given the relative time is
calculated backwards from <code>anchor_time</code>.</p>
</li>
<li>
<p><code>-r</code><br />
The argument passed is to be parsed as a relative time.</p>
</li>
<li>
<p><code>-R</code> <code>anchor_time</code><br />
The argument passed is to be parsed as a relative time. The time is
relative to <code>anchor_time</code>, a time in seconds since the epoch, and
the returned value is the absolute time corresponding to advancing
<code>anchor_time</code> by the relative time given. This allows lengths of
months to be correctly taken into account. If the final day does not
exist in the given month, the last day of the final month is given.
For example, if the anchor time is during 31st January 2007 and the
relative time is 1 month, the final time is the same time of day
during 28th February 2007.</p>
</li>
<li>
<p><code>-s</code><br />
In addition to setting <code>REPLY</code>, set <code>REPLY2</code> to the remainder of the
argument after the date and time have been stripped. This is empty
if the option <code>-A</code> was given.</p>
</li>
<li>
<p><code>-t</code><br />
Allow a time with no date specification. The date is assumed to be
today. The behaviour is unspecified if the iron tongue of midnight
is tolling twelve.</p>
</li>
</ul>
<p><span id="index-calendar_005fshow"></span></p>
<p><code>calendar_show</code></p>
<p>The function used by default to display events. It accepts a start time
and end time for events, both in epoch seconds, and an event
description.</p>
<p>The event is always printed to standard output. If the command line
editor is active (which will usually be the case) the command line will
be redisplayed after the output.</p>
<p>If the parameter <code>DISPLAY</code> is set and the start and end times are the
same (indicating a scheduled event), the function uses the command
<code>xmessage</code> to display a window with the event details.</p>
<hr />
<p><span id="Calendar-Bugs"></span> <span id="Bugs"></span></p>
<h2 id="236-bugs"><a class="header" href="#236-bugs">23.6 Bugs</a></h2>
<p>As the system is based entirely on shell functions (with a little
support from the <code>zsh/datetime</code> module) the mechanisms used are not as
robust as those provided by a dedicated calendar utility. Consequently
the user should not rely on the shell for vital alerts.</p>
<p>There is no <code>calendar_delete</code> function.</p>
<p>There is no localization support for dates and times, nor any support
for the use of time zones.</p>
<p>Relative periods of months and years do not take into account the
variable number of days.</p>
<p>The <code>calendar_show</code> function is currently hardwired to use <code>xmessage</code>
for displaying alerts on X Window System displays. This should be
configurable and ideally integrate better with the desktop.</p>
<p><code>calendar_lockfiles</code> hangs the shell while waiting for a lock on a file.
If called from a scheduled task, it should instead reschedule the event
that caused it.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="TCP-Function-System.html#24-tcp-function-system">24 TCP Function System</a>
<ul>
<li><a href="TCP-Function-System.html#241-description">24.1 Description</a></li>
<li><a href="TCP-Function-System.html#242-tcp-user-functions">24.2 TCP User Functions</a>
<ul>
<li><a href="TCP-Function-System.html#2421-basic-io">24.2.1 Basic I/O</a></li>
<li><a href="TCP-Function-System.html#2422-session-management">24.2.2 Session Management</a></li>
<li><a href="TCP-Function-System.html#2423-advanced-io">24.2.3 Advanced I/O</a></li>
<li><a href="TCP-Function-System.html#2424-one-shot-file-transfer">24.2.4 ‘One-shot’ file transfer</a></li>
</ul>
</li>
<li><a href="TCP-Function-System.html#243-tcp-user-defined-functions">24.3 TCP User-defined Functions</a></li>
<li><a href="TCP-Function-System.html#244-tcp-utility-functions">24.4 TCP Utility Functions</a></li>
<li><a href="TCP-Function-System.html#245-tcp-user-parameters">24.5 TCP User Parameters</a></li>
<li><a href="TCP-Function-System.html#246-tcp-user-defined-parameters">24.6 TCP User-defined Parameters</a></li>
<li><a href="TCP-Function-System.html#247-tcp-utility-parameters">24.7 TCP Utility Parameters</a></li>
<li><a href="TCP-Function-System.html#248-tcp-examples">24.8 TCP Examples</a></li>
<li><a href="TCP-Function-System.html#249-tcp-bugs">24.9 TCP Bugs</a></li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="TCP-Function-System"></span>
<span id="TCP-Function-System-1"></span></p>
<h1 id="24-tcp-function-system"><a class="header" href="#24-tcp-function-system">24 TCP Function System</a></h1>
<p><span id="index-TCP-function-system"></span>
<span id="index-ztcp_002c-function-system-based-on"></span></p>
<hr />
<p><span id="Description"></span></p>
<h2 id="241-description"><a class="header" href="#241-description">24.1 Description</a></h2>
<p>A module <code>zsh/net/tcp</code> is provided to provide network I/O over TCP/IP
from within the shell; see its description in <a href="Zsh-Modules.html#Zsh-Modules">Zsh
Modules</a>. This manual page describes a
function suite based on the module. If the module is installed, the
functions are usually installed at the same time, in which case they
will be available for autoloading in the default function search path.
In addition to the <code>zsh/net/tcp</code> module, the <code>zsh/zselect</code> module is
used to implement timeouts on read operations. For troubleshooting tips,
consult the corresponding advice for the <code>zftp</code> functions described in
<a href="Zftp-Function-System.html#Zftp-Function-System">Zftp Function System</a>.</p>
<p>There are functions corresponding to the basic I/O operations open,
close, read and send, named <code>tcp_open</code> etc., as well as a function
<code>tcp_expect</code> for pattern match analysis of data read as input. The
system makes it easy to receive data from and send data to multiple
named sessions at once. In addition, it can be linked with the shell’s
line editor in such a way that input data is automatically shown at the
terminal. Other facilities available including logging, filtering and
configurable output prompts.</p>
<p>To use the system where it is available, it should be enough to
‘<code>autoload -U tcp_open</code>’ and run <code>tcp_open</code> as documented below to
start a session. The <code>tcp_open</code> function will autoload the remaining
functions.</p>
<hr />
<p><span id="TCP-Functions"></span> <span id="TCP-User-Functions"></span></p>
<h2 id="242-tcp-user-functions"><a class="header" href="#242-tcp-user-functions">24.2 TCP User Functions</a></h2>
<hr />
<p><span id="Basic-I_002fO"></span></p>
<h3 id="2421-basic-io"><a class="header" href="#2421-basic-io">24.2.1 Basic I/O</a></h3>
<p><span id="index-tcp_005fopen"></span></p>
<p><code>tcp_open</code> [ <code>-qz</code> ] <code>host port</code> [ <code>sess</code> ]</p>
<p><code>tcp_open</code> [ <code>-qz</code> ] [ <code>-s</code> <code>sess</code> | <code>-l</code> <code>sess</code>[<code>,</code>...] ] ...</p>
<p><code>tcp_open</code> [ <code>-qz</code> ] [ <code>-a</code> <code>fd</code> | <code>-f</code> <code>fd</code> ] [ <code>sess</code> ]</p>
<p>Open a new session. In the first and simplest form, open a TCP
connection to host <code>host</code> at port <code>port</code>; numeric and symbolic forms are
understood for both.</p>
<p>If <code>sess</code> is given, this becomes the name of the session which can be
used to refer to multiple different TCP connections. If <code>sess</code> is not
given, the function will invent a numeric name value (note this is <em>not</em>
the same as the file descriptor to which the session is attached). It is
recommended that session names not include ‘funny’ characters, where
funny characters are not well-defined but certainly do not include
alphanumerics or underscores, and certainly do include whitespace.</p>
<p>In the second case, one or more sessions to be opened are given by name.
A single session name is given after <code>-s</code> and a comma-separated list
after <code>-l</code>; both options may be repeated as many times as necessary. A
failure to open any session causes <code>tcp_open</code> to abort. The host and
port are read from the file <code>.ztcp_sessions</code> in the same directory as
the user’s zsh initialisation files, i.e. usually the home directory,
but <code>$ZDOTDIR</code> if that is set. The file consists of lines each giving a
session name and the corresponding host and port, in that order (note
the session name comes first, not last), separated by whitespace.</p>
<p>The third form allows passive and fake TCP connections. If the option
<code>-a</code> is used, its argument is a file descriptor open for listening for
connections. No function front-end is provided to open such a file
descriptor, but a call to ‘<code>ztcp -l</code> <code>port</code>’ will create one with the
file descriptor stored in the parameter <code>$REPLY</code>. The listening port can
be closed with ‘<code>ztcp -c</code> <code>fd</code>’. A call to ‘<code>tcp_open -a</code> <code>fd</code>’ will
block until a remote TCP connection is made to <code>port</code> on the local
machine. At this point, a session is created in the usual way and is
largely indistinguishable from an active connection created with one of
the first two forms.</p>
<p>If the option <code>-f</code> is used, its argument is a file descriptor which is
used directly as if it were a TCP session. How well the remainder of the
TCP function system copes with this depends on what actually underlies
this file descriptor. A regular file is likely to be unusable; a FIFO
(pipe) of some sort will work better, but note that it is not a good
idea for two different sessions to attempt to read from the same FIFO at
once.</p>
<p>If the option <code>-q</code> is given with any of the three forms, <code>tcp_open</code> will
not print informational messages, although it will in any case exit with
an appropriate status.</p>
<p>If the line editor (zle) is in use, which is typically the case if the
shell is interactive, <code>tcp_open</code> installs a handler inside zle which
will check for new data at the same time as it checks for keyboard
input. This is convenient as the shell consumes no CPU time while
waiting; the test is performed by the operating system. Giving the
option <code>-z</code> to any of the forms of <code>tcp_open</code> prevents the handler from
being installed, so data must be read explicitly. Note, however, this is
not necessary for executing complete sets of send and read commands from
a function, as zle is not active at this point. Generally speaking, the
handler is only active when the shell is waiting for input at a command
prompt or in the <code>vared</code> builtin. The option has no effect if zle is not
active; ‘<code>[[ -o zle]]</code>’ will test for this.</p>
<p>The first session to be opened becomes the current session and
subsequent calls to <code>tcp_open</code> do not change it. The current session is
stored in the parameter <code>$TCP_SESS</code>; see below for more detail about the
parameters used by the system.</p>
<p>The function <code>tcp_on_open</code>, if defined, is called when a session is
opened. See the description below.</p>
<p><span id="index-tcp_005fclose"></span></p>
<p><code>tcp_close</code> [ <code>-qn</code> ] [ <code>-a</code> | <code>-l</code> <code>sess</code>[<code>,</code>...] | <code>sess</code> ... ]</p>
<p>Close the named sessions, or the current session if none is given, or
all open sessions if <code>-a</code> is given. The options <code>-l</code> and <code>-s</code> are both
handled for consistency with <code>tcp_open</code>, although the latter is
redundant.</p>
<p>If the session being closed is the current one, <code>$TCP_SESS</code> is unset,
leaving no current session, even if there are other sessions still open.</p>
<p>If the session was opened with <code>tcp_open -f</code>, the file descriptor is
closed so long as it is in the range 0 to 9 accessible directly from the
command line. If the option <code>-n</code> is given, no attempt will be made to
close file descriptors in this case. The <code>-n</code> option is not used for
genuine <code>ztcp</code> session; the file descriptors are always closed with the
session.</p>
<p>If the option <code>-q</code> is given, no informational messages will be printed.</p>
<p><span id="index-tcp_005fread"></span></p>
<p><code>tcp_read </code>[ <code>-bdq</code> ] [ <code>-t</code> <code>TO</code> ] [ <code>-T</code> <code>TO</code> ]</p>
<p><code>         </code>[ <code>-a</code> | <code>-u</code> <code>fd</code>[<code>,</code>...] | <code>-l</code> <code>sess</code>[<code>,</code>...] | <code>-s</code>
<code>sess</code> ... ]</p>
<p>Perform a read operation on the current session, or on a list of
sessions if any are given with <code>-u</code>, <code>-l</code> or <code>-s</code>, or all open sessions
if the option <code>-a</code> is given. Any of the <code>-u</code>, <code>-l</code> or <code>-s</code> options may
be repeated or mixed together. The <code>-u</code> option specifies a file
descriptor directly (only those managed by this system are useful), the
other two specify sessions as described for <code>tcp_open</code> above.</p>
<p>The function checks for new data available on all the sessions listed.
Unless the <code>-b</code> option is given, it will not block waiting for new data.
Any one line of data from any of the available sessions will be read,
stored in the parameter <code>$TCP_LINE</code>, and displayed to standard output
unless <code>$TCP_SILENT</code> contains a non-empty string. When printed to
standard output the string <code>$TCP_PROMPT</code> will be shown at the start of
the line; the default form for this includes the name of the session
being read. See below for more information on these parameters. In this
mode, <code>tcp_read</code> can be called repeatedly until it returns status 2
which indicates all pending input from all specified sessions has been
handled.</p>
<p>With the option <code>-b</code>, equivalent to an infinite timeout, the function
will block until a line is available to read from one of the specified
sessions. However, only a single line is returned.</p>
<p>The option <code>-d</code> indicates that all pending input should be drained. In
this case <code>tcp_read</code> may process multiple lines in the manner given
above; only the last is stored in <code>$TCP_LINE</code>, but the complete set is
stored in the array <code>$tcp_lines</code>. This is cleared at the start of each
call to <code>tcp_read</code>.</p>
<p>The options <code>-t</code> and <code>-T</code> specify a timeout in seconds, which may be a
floating point number for increased accuracy. With <code>-t</code> the timeout is
applied before each line read. With <code>-T</code>, the timeout applies to the
overall operation, possibly including multiple read operations if the
option <code>-d</code> is present; without this option, there is no distinction
between <code>-t</code> and <code>-T</code>.</p>
<p>The function does not print informational messages, but if the option
<code>-q</code> is given, no error message is printed for a non-existent session.</p>
<p>A return status of 2 indicates a timeout or no data to read. Any other
non-zero return status indicates some error condition.</p>
<p>See <code>tcp_log</code> for how to control where data is sent by <code>tcp_read</code>.</p>
<p><span id="index-tcp_005fsend"></span></p>
<p><code>tcp_send</code> [ <code>-cnq</code> ] [ <code>-s</code> <code>sess</code> | <code>-l</code> <code>sess</code>[<code>,</code>...] ] <code>data</code>
...</p>
<p><code>tcp_send</code> [ <code>-cnq</code> ] <code>-a</code> <code>data</code> ...</p>
<p>Send the supplied data strings to all the specified sessions in turn.
The underlying operation differs little from a ‘<code>print -r</code>’ to the
session’s file descriptor, although it attempts to prevent the shell
from dying owing to a <code>SIGPIPE</code> caused by an attempt to write to a
defunct session.</p>
<p>The option <code>-c</code> causes <code>tcp_send</code> to behave like <code>cat</code>. It reads lines
from standard input until end of input and sends them in turn to the
specified session(s) exactly as if they were given as <code>data</code> arguments
to individual <code>tcp_send</code> commands.</p>
<p>The option <code>-n</code> prevents <code>tcp_send</code> from putting a newline at the end of
the data strings.</p>
<p>The remaining options all behave as for <code>tcp_read</code>.</p>
<p>The data arguments are not further processed once they have been passed
to <code>tcp_send</code>; they are simply passed down to <code>print -r</code>.</p>
<p>If the parameter <code>$TCP_OUTPUT</code> is a non-empty string and logging is
enabled then the data sent to each session will be echoed to the log
file(s) with <code>$TCP_OUTPUT</code> in front where appropriate, much in the
manner of <code>$TCP_PROMPT</code>.</p>
<hr />
<p><span id="Session-Management"></span></p>
<h3 id="2422-session-management"><a class="header" href="#2422-session-management">24.2.2 Session Management</a></h3>
<p><span id="index-tcp_005falias"></span></p>
<p><code>tcp_alias</code> [ <code>-q</code> ] <code>alias``=``sess</code> ...</p>
<p><code>tcp_alias</code> [ <code>-q</code> ] [ <code>alias</code> ... ]</p>
<p><code>tcp_alias</code> <code>-d</code> [ <code>-q</code> ] <code>alias</code> ...</p>
<p>This function is not particularly well tested.</p>
<p>The first form creates an alias for a session name; <code>alias</code> can then be
used to refer to the existing session <code>sess</code>. As many aliases may be
listed as required.</p>
<p>The second form lists any aliases specified, or all aliases if none.</p>
<p>The third form deletes all the aliases listed. The underlying sessions
are not affected.</p>
<p>The option <code>-q</code> suppresses an inconsistently chosen subset of error
messages.</p>
<p><span id="index-tcp_005flog"></span></p>
<p><code>tcp_log</code> [ <code>-asc</code> ] [ <code>-n</code> | <code>-N</code> ] [ <code>logfile</code> ]</p>
<p>With an argument <code>logfile</code>, all future input from <code>tcp_read</code> will be
logged to the named file. Unless <code>-a</code> (append) is given, this file will
first be truncated or created empty. With no arguments, show the current
status of logging.</p>
<p>With the option <code>-s</code>, per-session logging is enabled. Input from
<code>tcp_read</code> is output to the file <code>logfile``.``sess</code>. As the session is
automatically discriminated by the filename, the contents are raw (no
<code>$TCP_PROMPT</code>). The option <code>-a</code> applies as above. Per-session logging
and logging of all data in one file are not mutually exclusive.</p>
<p>The option <code>-c</code> closes all logging, both complete and per-session logs.</p>
<p>The options <code>-n</code> and <code>-N</code> respectively turn off or restore output of
data read by <code>tcp_read</code> to standard output; hence ‘<code>tcp_log -cn</code>’ turns
off all output by <code>tcp_read</code>.</p>
<p>The function is purely a convenient front end to setting the parameters
<code>$TCP_LOG</code>, <code>$TCP_LOG_SESS</code>, <code>$TCP_SILENT</code>, which are described below.</p>
<p><span id="index-tcp_005frename"></span></p>
<p><code>tcp_rename</code> <code>old</code> <code>new</code></p>
<p>Rename session <code>old</code> to session <code>new</code>. The old name becomes invalid.</p>
<p><span id="index-tcp_005fsess"></span></p>
<p><code>tcp_sess</code> [ <code>sess</code> [ <code>command</code> [ <code>arg</code> ... ] ] ]</p>
<p>With no arguments, list all the open sessions and associated file
descriptors. The current session is marked with a star. For use in
functions, direct access to the parameters <code>$tcp_by_name</code>, <code>$tcp_by_fd</code>
and <code>$TCP_SESS</code> is probably more convenient; see below.</p>
<p>With a <code>sess</code> argument, set the current session to <code>sess</code>. This is
equivalent to changing <code>$TCP_SESS</code> directly.</p>
<p>With additional arguments, temporarily set the current session while
executing ‘<code>command</code> <code>arg</code> ...’. <code>command</code> is re-evaluated so as to
expand aliases etc., but the remaining <code>arg</code>s are passed through as that
appear to <code>tcp_sess</code>. The original session is restored when <code>tcp_sess</code>
exits.</p>
<hr />
<p><span id="Advanced-I_002fO"></span></p>
<h3 id="2423-advanced-io"><a class="header" href="#2423-advanced-io">24.2.3 Advanced I/O</a></h3>
<p><span id="index-tcp_005fcommand"></span></p>
<p><code>tcp_command</code> <code>send-option</code> ... <code>send-argument</code> ...</p>
<p>This is a convenient front-end to <code>tcp_send</code>. All arguments are passed
to <code>tcp_send</code>, then the function pauses waiting for data. While data is
arriving at least every <code>$TCP_TIMEOUT</code> (default 0.3) seconds, data is
handled and printed out according to the current settings. Status 0 is
always returned.</p>
<p>This is generally only useful for interactive use, to prevent the
display becoming fragmented by output returned from the connection.
Within a programme or function it is generally better to handle reading
data by a more explicit method.</p>
<p><span id="index-tcp_005fexpect"></span></p>
<p><code>tcp_expect </code>[ <code>-q</code> ] [ <code>-p</code> <code>var</code> | <code>-P</code> <code>var</code> ] [ <code>-t</code> <code>TO</code> |
<code>-T</code> <code>TO</code> ]</p>
<p><code>           </code>[ <code>-a</code> | <code>-s</code> <code>sess</code> | <code>-l</code> <code>sess</code>[<code>,</code>...] ] <code>pattern</code>
...</p>
<p>Wait for input matching any of the given <code>pattern</code>s from any of the
specified sessions. Input is ignored until an input line matches one of
the given patterns; at this point status zero is returned, the matching
line is stored in <code>$TCP_LINE</code>, and the full set of lines read during the
call to <code>tcp_expect</code> is stored in the array <code>$tcp_expect_lines</code>.</p>
<p>Sessions are specified in the same way as <code>tcp_read</code>: the default is to
use the current session, otherwise the sessions specified by <code>-a</code>, <code>-s</code>,
or <code>-l</code> are used.</p>
<p>Each <code>pattern</code> is a standard zsh extended-globbing pattern; note that it
needs to be quoted to avoid it being expanded immediately by filename
generation. It must match the full line, so to match a substring there
must be a ‘<code>*</code>’ at the start and end. The line matched against includes
the <code>$TCP_PROMPT</code> added by <code>tcp_read</code>. It is possible to include the
globbing flags ‘<code>#b</code>’ or ‘<code>#m</code>’ in the patterns to make backreferences
available in the parameters <code>$MATCH</code>, <code>$match</code>, etc., as described in
the base zsh documentation on pattern matching.</p>
<p>Unlike <code>tcp_read</code>, the default behaviour of <code>tcp_expect</code> is to block
indefinitely until the required input is found. This can be modified by
specifying a timeout with <code>-t</code> or <code>-T</code>; these function as in <code>tcp_read</code>,
specifying a per-read or overall timeout, respectively, in seconds, as
an integer or floating-point number. As <code>tcp_read</code>, the function returns
status 2 if a timeout occurs.</p>
<p>The function returns as soon as any one of the patterns given match. If
the caller needs to know which of the patterns matched, the option <code>-p</code>
<code>var</code> can be used; on return, <code>$var</code> is set to the number of the pattern
using ordinary zsh indexing, i.e. the first is 1, and so on. Note the
absence of a ‘<code>$</code>’ in front of <code>var</code>. To avoid clashes, the parameter
cannot begin with ‘<code>_expect</code>’. The index -1 is used if there is a
timeout and 0 if there is no match.</p>
<p>The option <code>-P</code> <code>var</code> works similarly to <code>-p</code>, but instead of numerical
indexes the regular arguments must begin with a prefix followed by a
colon: that prefix is then used as a tag to which <code>var</code> is set when the
argument matches. The tag <code>timeout</code> is used if there is a timeout and
the empty string if there is no match. Note it is matches do not need to
be distinguished.</p>
<p>The option <code>-q</code> is passed directly down to <code>tcp_read</code>.</p>
<p>As all input is done via <code>tcp_read</code>, all the usual rules about output of
lines read apply. One exception is that the parameter <code>$tcp_lines</code> will
only reflect the line actually matched by <code>tcp_expect</code>; use
<code>$tcp_expect_lines</code> for the full set of lines read during the function
call.</p>
<p><span id="index-tcp_005fproxy"></span></p>
<p><code>tcp_proxy</code></p>
<p>This is a simple-minded function to accept a TCP connection and execute
a command with I/O redirected to the connection. Extreme caution should
be taken as there is no security whatsoever and this can leave your
computer open to the world. Ideally, it should only be used behind a
firewall.</p>
<p>The first argument is a TCP port on which the function will listen.</p>
<p>The remaining arguments give a command and its arguments to execute with
standard input, standard output and standard error redirected to the
file descriptor on which the TCP session has been accepted. If no
command is given, a new zsh is started. This gives everyone on your
network direct access to your account, which in many cases will be a bad
thing.</p>
<p>The command is run in the background, so <code>tcp_proxy</code> can then accept new
connections. It continues to accept new connections until interrupted.</p>
<p><span id="index-tcp_005fspam"></span></p>
<p><code>tcp_spam</code> [ <code>-ertv</code> ] [ <code>-a</code> | <code>-s</code> <code>sess</code> | <code>-l</code> <code>sess</code>[<code>,</code>...]
] <code>cmd</code> [ <code>arg</code> ... ]</p>
<p>Execute ‘<code>cmd</code> [ <code>arg</code> ... ]’ for each session in turn. Note this
executes the command and arguments; it does not send the command line as
data unless the <code>-t</code> (transmit) option is given.</p>
<p>The sessions may be selected explicitly with the standard <code>-a</code>, <code>-s</code> or
<code>-l</code> options, or may be chosen implicitly. If none of the three options
is given the rules are: first, if the array <code>$tcp_spam_list</code> is set,
this is taken as the list of sessions, otherwise all sessions are taken.
Second, any sessions given in the array <code>$tcp_no_spam_list</code> are removed
from the list of sessions.</p>
<p>Normally, any sessions added by the ‘<code>-a</code>’ flag or when all sessions are
chosen implicitly are spammed in alphabetic order; sessions given by the
<code>$tcp_spam_list</code> array or on the command line are spammed in the order
given. The <code>-r</code> flag reverses the order however it was arrived it.</p>
<p>The <code>-v</code> flag specifies that a <code>$TCP_PROMPT</code> will be output before each
session. This is output after any modification to <code>TCP_SESS</code> by the
user-defined <code>tcp_on_spam</code> function described below. (Obviously that
function is able to generate its own output.)</p>
<p>If the option <code>-e</code> is present, the line given as ‘<code>cmd</code> [ <code>arg</code> ... ]’
is executed using <code>eval</code>, otherwise it is executed without any further
processing.</p>
<p><span id="index-tcp_005ftalk"></span></p>
<p><code>tcp_talk</code></p>
<p>This is a fairly simple-minded attempt to force input to the line editor
to go straight to the default <code>TCP_SESS</code>.</p>
<p>An escape string, <code>$TCP_TALK_ESCAPE</code>, default ‘<code>:</code>’, is used to allow
access to normal shell operation. If it is on its own at the start of
the line, or followed only by whitespace, the line editor returns to
normal operation. Otherwise, the string and any following whitespace are
skipped and the remainder of the line executed as shell input without
any change of the line editor’s operating mode.</p>
<p>The current implementation is somewhat deficient in terms of use of the
command history. For this reason, many users will prefer to use some
form of alternative approach for sending data easily to the current
session. One simple approach is to alias some special character (such as
‘<code>%</code>’) to ‘<code>tcp_command -``-</code>’.</p>
<p><span id="index-tcp_005fwait"></span></p>
<p><code>tcp_wait</code></p>
<p>The sole argument is an integer or floating point number which gives the
seconds to delay. The shell will do nothing for that period except wait
for input on all TCP sessions by calling <code>tcp_read -a</code>. This is similar
to the interactive behaviour at the command prompt when zle handlers are
installed.</p>
<hr />
<p><span id="g_t_0060One_002dshot_0027-file-transfer"></span></p>
<h3 id="2424-one-shot-file-transfer"><a class="header" href="#2424-one-shot-file-transfer">24.2.4 ‘One-shot’ file transfer</a></h3>
<ul>
<li>
<p><code>tcp_point</code> <code>port</code><br />
<code>tcp_shoot</code> <code>host</code> <code>port</code><br />
This pair of functions provide a simple way to transfer a file
between two hosts within the shell. Note, however, that bulk data
transfer is currently done using <code>cat</code>. <code>tcp_point</code> reads any data
arriving at <code>port</code> and sends it to standard output; <code>tcp_shoot</code>
connects to <code>port</code> on <code>host</code> and sends its standard input. Any
unused <code>port</code> may be used; the standard mechanism for picking a port
is to think of a random four-digit number above 1024 until one
works.</p>
<p>To transfer a file from host <code>woodcock</code> to host <code>springes</code>, on
<code>springes</code>:</p>
<div class="example">
<pre><code class="language-example">tcp_point 8091 &gt;output_file
</code></pre>
</div>
<p>and on <code>woodcock</code>:</p>
<div class="example">
<pre><code class="language-example">tcp_shoot springes 8091 &lt;input_file
</code></pre>
</div>
<p>As these two functions do not require <code>tcp_open</code> to set up a TCP
connection first, they may need to be autoloaded separately.</p>
</li>
</ul>
<hr />
<p><span id="TCP-User_002ddefined-Functions"></span></p>
<h2 id="243-tcp-user-defined-functions"><a class="header" href="#243-tcp-user-defined-functions">24.3 TCP User-defined Functions</a></h2>
<p>Certain functions, if defined by the user, will be called by the
function system in certain contexts. This facility depends on the module
<code>zsh/parameter</code>, which is usually available in interactive shells as the
completion system depends on it. None of the functions need be defined;
they simply provide convenient hooks when necessary.</p>
<p>Typically, these are called after the requested action has been taken,
so that the various parameters will reflect the new state.</p>
<p><span id="index-tcp_005fon_005falias"></span></p>
<p><code>tcp_on_alias</code> <code>alias</code> <code>fd</code></p>
<p>When an alias is defined, this function will be called with two
arguments: the name of the alias, and the file descriptor of the
corresponding session.</p>
<p><span id="index-tcp_005fon_005fawol"></span></p>
<p><code>tcp_on_awol</code> <code>sess</code> <code>fd</code></p>
<p>If the function <code>tcp_fd_handler</code> is handling input from the line editor
and detects that the file descriptor is no longer reusable, by default
it removes it from the list of file descriptors handled by this method
and prints a message. If the function <code>tcp_on_awol</code> is defined it is
called immediately before this point. It may return status 100, which
indicates that the normal handling should still be performed; any other
return status indicates that no further action should be taken and the
<code>tcp_fd_handler</code> should return immediately with the given status.
Typically the action of <code>tcp_on_awol</code> will be to close the session.</p>
<p>The variable <code>TCP_INVALIDATE_ZLE</code> will be a non-empty string if it is
necessary to invalidate the line editor display using ‘<code>zle -I</code>’ before
printing output from the function.</p>
<p>(‘AWOL’ is military jargon for ‘absent without leave’ or some variation.
It has no pre-existing technical meaning known to the author.)</p>
<p><span id="index-tcp_005fon_005fclose"></span></p>
<p><code>tcp_on_close</code> <code>sess</code> <code>fd</code></p>
<p>This is called with the name of a session being closed and the file
descriptor which corresponded to that session. Both will be invalid by
the time the function is called.</p>
<p><span id="index-tcp_005fon_005fopen"></span></p>
<p><code>tcp_on_open</code> <code>sess</code> <code>fd</code></p>
<p>This is called after a new session has been defined with the session
name and file descriptor as arguments. If it returns a non-zero status,
opening the session is assumed to fail and the session is closed again;
however, <code>tcp_open</code> will continue to attempt to open any remaining
sessions given on the command line.</p>
<p><span id="index-tcp_005fon_005frename"></span></p>
<p><code>tcp_on_rename</code> <code>oldsess</code> <code>fd</code> <code>newsess</code></p>
<p>This is called after a session has been renamed with the three arguments
old session name, file descriptor, new session name.</p>
<p><span id="index-tcp_005fon_005fspam"></span></p>
<p><code>tcp_on_spam</code> <code>sess</code> <code>command ...</code></p>
<p>This is called once for each session spammed, just <em>before</em> a command is
executed for a session by <code>tcp_spam</code>. The arguments are the session name
followed by the command list to be executed. If <code>tcp_spam</code> was called
with the option <code>-t</code>, the first command will be <code>tcp_send</code>.</p>
<p>This function is called after <code>$TCP_SESS</code> is set to reflect the session
to be spammed, but before any use of it is made. Hence it is possible to
alter the value of <code>$TCP_SESS</code> within this function. For example, the
session arguments to <code>tcp_spam</code> could include extra information to be
stripped off and processed in <code>tcp_on_spam</code>.</p>
<p>If the function sets the parameter <code>$REPLY</code> to ‘<code>done</code>’, the command
line is not executed; in addition, no prompt is printed for the <code>-v</code>
option to <code>tcp_spam</code>.</p>
<p><span id="index-tcp_005fon_005funalias"></span></p>
<p><code>tcp_on_unalias</code> <code>alias</code> <code>fd</code></p>
<p>This is called with the name of an alias and the corresponding session’s
file descriptor after an alias has been deleted.</p>
<hr />
<p><span id="TCP-Utility-Functions"></span></p>
<h2 id="244-tcp-utility-functions"><a class="header" href="#244-tcp-utility-functions">24.4 TCP Utility Functions</a></h2>
<p>The following functions are used by the TCP function system but will
rarely if ever need to be called directly.</p>
<p><span id="index-tcp_005ffd_005fhandler"></span></p>
<p><code>tcp_fd_handler</code></p>
<p>This is the function installed by <code>tcp_open</code> for handling input from
within the line editor, if that is required. It is in the format
documented for the builtin ‘<code>zle -F</code>’ in <a href="Zsh-Line-Editor.html#Zle-Builtins">Zle
Builtins</a> .</p>
<p>While active, the function sets the parameter <code>TCP_HANDLER_ACTIVE</code> to 1.
This allows shell code called internally (for example, by setting
<code>tcp_on_read</code>) to tell if is being called when the shell is otherwise
idle at the editor prompt.</p>
<p><span id="index-tcp_005foutput"></span></p>
<p><code>tcp_output</code> [ <code>-q</code> ] <code>-P</code> <code>prompt</code> <code>-F</code> <code>fd</code> <code>-S</code> <code>sess</code></p>
<p>This function is used for both logging and handling output to standard
output, from within <code>tcp_read</code> and (if <code>$TCP_OUTPUT</code> is set) <code>tcp_send</code>.</p>
<p>The <code>prompt</code> to use is specified by <code>-P</code>; the default is the empty
string. It can contain:</p>
<ul>
<li>
<p><code>%c</code><br />
Expands to 1 if the session is the current session, otherwise 0.
Used with ternary expressions such as ‘<code>%(c.-.+)</code>’ to output ‘<code>+</code>’
for the current session and ‘<code>-</code>’ otherwise.</p>
</li>
<li>
<p><code>%f</code><br />
Replaced by the session’s file descriptor.</p>
</li>
<li>
<p><code>%s</code><br />
Replaced by the session name.</p>
</li>
<li>
<p><code>%%</code><br />
Replaced by a single ‘<code>%</code>’.</p>
</li>
</ul>
<p>The option <code>-q</code> suppresses output to standard output, but not to any log
files which are configured.</p>
<p>The <code>-S</code> and <code>-F</code> options are used to pass in the session name and file
descriptor for possible replacement in the prompt.</p>
<hr />
<p><span id="TCP-Parameters"></span> <span id="TCP-User-Parameters"></span></p>
<h2 id="245-tcp-user-parameters"><a class="header" href="#245-tcp-user-parameters">24.5 TCP User Parameters</a></h2>
<p>Parameters follow the usual convention that uppercase is used for
scalars and integers, while lowercase is used for normal and associative
array. It is always safe for user code to read these parameters. Some
parameters may also be set; these are noted explicitly. Others are
included in this group as they are set by the function system for the
user’s benefit, i.e. setting them is typically not useful but is benign.</p>
<p>For example, ‘<code>local TCP_SILENT=1</code>’ specifies that data read during the
function call will not be printed to standard output, regardless of the
setting outside the function. Likewise, ‘<code>local TCP_SESS=``sess</code>’ sets a
session for the duration of a function, and ‘<code>local TCP_PROMPT=</code>’
specifies that no prompt is used for input during the function.</p>
<p><span id="index-tcp_005fexpect_005flines"></span></p>
<p><code>tcp_expect_lines</code></p>
<p>Array. The set of lines read during the last call to <code>tcp_expect</code>,
including the last (<code>$TCP_LINE</code>).</p>
<p><span id="index-tcp_005ffilter"></span></p>
<p><code>tcp_filter</code></p>
<p>Array. May be set directly. A set of extended globbing patterns which,
if matched in <code>tcp_output</code>, will cause the line not to be printed to
standard output. The patterns should be defined as described for the
arguments to <code>tcp_expect</code>. Output of line to log files is not affected.</p>
<p><span id="index-TCP_005fHANDLER_005fACTIVE"></span></p>
<p><code>TCP_HANDLER_ACTIVE</code></p>
<p>Scalar. Set to 1 within <code>tcp_fd_handler</code> to indicate to functions called
recursively that they have been called during an editor session.
Otherwise unset.</p>
<p><span id="index-TCP_005fLINE"></span></p>
<p><code>TCP_LINE</code></p>
<p>The last line read by <code>tcp_read</code>, and hence also <code>tcp_expect</code>.</p>
<p><span id="index-TCP_005fLINE_005fFD"></span></p>
<p><code>TCP_LINE_FD</code></p>
<p>The file descriptor from which <code>$TCP_LINE</code> was read.
<code>${tcp_by_fd[$TCP_LINE_FD]}</code> will give the corresponding session name.</p>
<p><span id="index-tcp_005flines"></span></p>
<p><code>tcp_lines</code></p>
<p>Array. The set of lines read during the last call to <code>tcp_read</code>,
including the last (<code>$TCP_LINE</code>).</p>
<p><span id="index-TCP_005fLOG"></span></p>
<p><code>TCP_LOG</code></p>
<p>May be set directly, although it is also controlled by <code>tcp_log</code>. The
name of a file to which output from all sessions will be sent. The
output is proceeded by the usual <code>$TCP_PROMPT</code>. If it is not an absolute
path name, it will follow the user’s current directory.</p>
<p><span id="index-TCP_005fLOG_005fSESS"></span></p>
<p><code>TCP_LOG_SESS</code></p>
<p>May be set directly, although it is also controlled by <code>tcp_log</code>. The
prefix for a set of files to which output from each session separately
will be sent; the full filename is <code>${TCP_LOG_SESS}.``sess</code>. Output to
each file is raw; no prompt is added. If it is not an absolute path
name, it will follow the user’s current directory.</p>
<p><span id="index-tcp_005fno_005fspam_005flist"></span></p>
<p><code>tcp_no_spam_list</code></p>
<p>Array. May be set directly. See <code>tcp_spam</code> for how this is used.</p>
<p><span id="index-TCP_005fOUTPUT"></span></p>
<p><code>TCP_OUTPUT</code></p>
<p>May be set directly. If a non-empty string, any data sent to a session
by <code>tcp_send</code> will be logged. This parameter gives the prompt to be used
in a file specified by <code>$TCP_LOG</code> but not in a file generated from
<code>$TCP_LOG_SESS</code>. The prompt string has the same format as <code>TCP_PROMPT</code>
and the same rules for its use apply.</p>
<p><span id="index-TCP_005fPROMPT"></span></p>
<p><code>TCP_PROMPT</code></p>
<p>May be set directly. Used as the prefix for data read by <code>tcp_read</code>
which is printed to standard output or to the log file given by
<code>$TCP_LOG</code>, if any. Any ‘<code>%s</code>’, ‘<code>%f</code>’ or ‘<code>%%</code>’ occurring in the string
will be replaced by the name of the session, the session’s underlying
file descriptor, or a single ‘<code>%</code>’, respectively. The expression ‘<code>%c</code>’
expands to 1 if the session being read is the current session, else 0;
this is most useful in ternary expressions such as ‘<code>%(c.-.+)</code>’ which
outputs ‘<code>+</code>’ if the session is the current one, else ‘<code>-</code>’.</p>
<p>If the prompt starts with <code>%P</code>, this is stripped and the complete result
of the previous stage is passed through standard prompt <code>%</code>-style
formatting before being output.</p>
<p><span id="index-TCP_005fREAD_005fDEBUG"></span></p>
<p><code>TCP_READ_DEBUG</code></p>
<p>May be set directly. If this has non-zero length, <code>tcp_read</code> will give
some limited diagnostics about data being read.</p>
<p><span id="index-TCP_005fSECONDS_005fSTART"></span></p>
<p><code>TCP_SECONDS_START</code></p>
<p>This value is created and initialised to zero by tcp_open.</p>
<p>The functions <code>tcp_read</code> and <code>tcp_expect</code> use the shell’s <code>SECONDS</code>
parameter for their own timing purposes. If that parameter is not of
floating point type on entry to one of the functions, it will create a
local parameter <code>SECONDS</code> which is floating point and set the parameter
<code>TCP_SECONDS_START</code> to the previous value of <code>$SECONDS</code>. If the
parameter is already floating point, it is used without a local copy
being created and <code>TCP_SECONDS_START</code> is not set. As the global value is
zero, the shell elapsed time is guaranteed to be the sum of <code>$SECONDS</code>
and <code>$TCP_SECONDS_START</code>.</p>
<p>This can be avoided by setting <code>SECONDS</code> globally to a floating point
value using ‘<code>typeset -F SECONDS</code>’; then the TCP functions will never
make a local copy and never set <code>TCP_SECONDS_START</code> to a non-zero value.</p>
<p><span id="index-TCP_005fSESS"></span></p>
<p><code>TCP_SESS</code></p>
<p>May be set directly. The current session; must refer to one of the
sessions established by <code>tcp_open</code>.</p>
<p><span id="index-TCP_005fSILENT"></span></p>
<p><code>TCP_SILENT</code></p>
<p>May be set directly, although it is also controlled by <code>tcp_log</code>. If of
non-zero length, data read by <code>tcp_read</code> will not be written to standard
output, though may still be written to a log file.</p>
<p><span id="index-tcp_005fspam_005flist"></span></p>
<p><code>tcp_spam_list</code></p>
<p>Array. May be set directly. See the description of the function
<code>tcp_spam</code> for how this is used.</p>
<p><span id="index-TCP_005fTALK_005fESCAPE"></span></p>
<p><code>TCP_TALK_ESCAPE</code></p>
<p>May be set directly. See the description of the function <code>tcp_talk</code> for
how this is used.</p>
<p><span id="index-TCP_005fTIMEOUT"></span></p>
<p><code>TCP_TIMEOUT</code></p>
<p>May be set directly. Currently this is only used by the function
<code>tcp_command</code>, see above.</p>
<hr />
<p><span id="TCP-User_002ddefined-Parameters"></span></p>
<h2 id="246-tcp-user-defined-parameters"><a class="header" href="#246-tcp-user-defined-parameters">24.6 TCP User-defined Parameters</a></h2>
<p>The following parameters are not set by the function system, but have a
special effect if set by the user.</p>
<p><span id="index-tcp_005fon_005fread"></span></p>
<p><code>tcp_on_read</code></p>
<p>This should be an associative array; if it is not, the behaviour is
undefined. Each key is the name of a shell function or other command,
and the corresponding value is a shell pattern (using <code>EXTENDED_GLOB</code>).
Every line read from a TCP session directly or indirectly using
<code>tcp_read</code> (which includes lines read by <code>tcp_expect</code>) is compared
against the pattern. If the line matches, the command given in the key
is called with two arguments: the name of the session from which the
line was read, and the line itself.</p>
<p>If any function called to handle a line returns a non-zero status, the
line is not output. Thus a <code>tcp_on_read</code> handler containing only the
instruction ‘<code>return 1</code>’ can be used to suppress output of particular
lines (see, however, <code>tcp_filter</code> above). However, the line is still
stored in <code>TCP_LINE</code> and <code>tcp_lines</code>; this occurs after all
<code>tcp_on_read</code> processing.</p>
<hr />
<p><span id="TCP-Utility-Parameters"></span></p>
<h2 id="247-tcp-utility-parameters"><a class="header" href="#247-tcp-utility-parameters">24.7 TCP Utility Parameters</a></h2>
<p>These parameters are controlled by the function system; they may be read
directly, but should not usually be set by user code.</p>
<p><span id="index-tcp_005faliases"></span></p>
<p><code>tcp_aliases</code></p>
<p>Associative array. The keys are the names of sessions established with
<code>tcp_open</code>; each value is a space-separated list of aliases which refer
to that session.</p>
<p><span id="index-tcp_005fby_005ffd"></span></p>
<p><code>tcp_by_fd</code></p>
<p>Associative array. The keys are session file descriptors; each value is
the name of that session.</p>
<p><span id="index-tcp_005fby_005fname"></span></p>
<p><code>tcp_by_name</code></p>
<p>Associative array. The keys are the names of sessions; each value is the
file descriptor associated with that session.</p>
<hr />
<p><span id="TCP-Examples"></span> <span id="TCP-Examples-1"></span></p>
<h2 id="248-tcp-examples"><a class="header" href="#248-tcp-examples">24.8 TCP Examples</a></h2>
<p>Here is a trivial example using a remote calculator.</p>
<p>To create a calculator server on port 7337 (see the <code>dc</code> manual page for
quite how infuriating the underlying command is):</p>
<div class="example">
<pre><code class="language-example">tcp_proxy 7337 dc
</code></pre>
</div>
<p>To connect to this from the same host with a session also named ‘<code>dc</code>’:</p>
<div class="example">
<pre><code class="language-example">tcp_open localhost 7337 dc
</code></pre>
</div>
<p>To send a command to the remote session and wait a short while for
output (assuming <code>dc</code> is the current session):</p>
<div class="example">
<pre><code class="language-example">tcp_command 2 4 + p
</code></pre>
</div>
<p>To close the session:</p>
<div class="example">
<pre><code class="language-example">tcp_close
</code></pre>
</div>
<p>The <code>tcp_proxy</code> needs to be killed to be stopped. Note this will not
usually kill any connections which have already been accepted, and also
that the port is not immediately available for reuse.</p>
<p>The following chunk of code puts a list of sessions into an xterm
header, with the current session followed by a star.</p>
<div class="example">
<pre><code class="language-example">print -n &quot;\033]2;TCP:&quot; ${(k)tcp_by_name:/$TCP_SESS/$TCP_SESS\*} &quot;\a&quot;
</code></pre>
</div>
<hr />
<p><span id="TCP-Bugs"></span> <span id="TCP-Bugs-1"></span></p>
<h2 id="249-tcp-bugs"><a class="header" href="#249-tcp-bugs">24.9 TCP Bugs</a></h2>
<p>The function <code>tcp_read</code> uses the shell’s normal <code>read</code> builtin. As this
reads a complete line at once, data arriving without a terminating
newline can cause the function to block indefinitely.</p>
<p>Though the function suite works well for interactive use and for data
arriving in small amounts, the performance when large amounts of data
are being exchanged is likely to be extremely poor.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="Zftp-Function-System.html#25-zftp-function-system">25 Zftp Function System</a>
<ul>
<li><a href="Zftp-Function-System.html#251-description">25.1 Description</a></li>
<li><a href="Zftp-Function-System.html#252-installation">25.2 Installation</a></li>
<li><a href="Zftp-Function-System.html#253-functions">25.3 Functions</a>
<ul>
<li><a href="Zftp-Function-System.html#2531-opening-a-connection">25.3.1 Opening a connection</a></li>
<li><a href="Zftp-Function-System.html#2532-directory-management">25.3.2 Directory management</a></li>
<li><a href="Zftp-Function-System.html#2533-status-commands">25.3.3 Status commands</a></li>
<li><a href="Zftp-Function-System.html#2534-retrieving-files">25.3.4 Retrieving files</a></li>
<li><a href="Zftp-Function-System.html#2535-sending-files">25.3.5 Sending files</a></li>
<li><a href="Zftp-Function-System.html#2536-closing-the-connection">25.3.6 Closing the connection</a></li>
<li><a href="Zftp-Function-System.html#2537-session-management">25.3.7 Session management</a></li>
<li><a href="Zftp-Function-System.html#2538-bookmarks">25.3.8 Bookmarks</a></li>
<li><a href="Zftp-Function-System.html#2539-other-functions">25.3.9 Other functions</a></li>
</ul>
</li>
<li><a href="Zftp-Function-System.html#254-miscellaneous-features">25.4 Miscellaneous Features</a>
<ul>
<li><a href="Zftp-Function-System.html#2541-configuration">25.4.1 Configuration</a></li>
<li><a href="Zftp-Function-System.html#2542-remote-globbing">25.4.2 Remote globbing</a></li>
<li><a href="Zftp-Function-System.html#2543-automatic-and-temporary-reopening">25.4.3 Automatic and temporary reopening</a></li>
<li><a href="Zftp-Function-System.html#2544-completion">25.4.4 Completion</a></li>
</ul>
</li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="Zftp-Function-System"></span>
<span id="Zftp-Function-System-1"></span></p>
<h1 id="25-zftp-function-system"><a class="header" href="#25-zftp-function-system">25 Zftp Function System</a></h1>
<p><span id="index-zftp-function-system"></span>
<span id="index-FTP_002c-functions-for-using-shell-as-client"></span></p>
<hr />
<p><span id="Description-4"></span></p>
<h2 id="251-description"><a class="header" href="#251-description">25.1 Description</a></h2>
<p>This describes the set of shell functions supplied with the source
distribution as an interface to the <code>zftp</code> builtin command, allowing you
to perform FTP operations from the shell command line or within
functions or scripts. The interface is similar to a traditional FTP
client (e.g. the <code>ftp</code> command itself, see man page ftp(1)), but as it
is entirely done within the shell all the familiar completion, editing
and globbing features, and so on, are present, and macros are
particularly simple to write as they are just ordinary shell functions.</p>
<p>The prerequisite is that the <code>zftp</code> command, as described in <a href="Zsh-Modules.html#The-zsh_002fzftp-Module">The
zsh/zftp Module</a> , must be
available in the version of <code>zsh</code> installed at your site. If the shell
is configured to load new commands at run time, it probably is: typing
‘<code>zmodload zsh/zftp</code>’ will make sure (if that runs silently, it has
worked). If this is not the case, it is possible <code>zftp</code> was linked into
the shell anyway: to test this, type ‘<code>which zftp</code>’ and if <code>zftp</code> is
available you will get the message ‘<code>zftp: shell built-in command</code>’.</p>
<p>Commands given directly with <code>zftp</code> builtin may be interspersed between
the functions in this suite; in a few cases, using <code>zftp</code> directly may
cause some of the status information stored in shell parameters to
become invalid. Note in particular the description of the variables
<code>$ZFTP_TMOUT</code>, <code>$ZFTP_PREFS</code> and <code>$ZFTP_VERBOSE</code> for <code>zftp</code>.</p>
<hr />
<p><span id="Installation"></span> <span id="Installation-1"></span></p>
<h2 id="252-installation"><a class="header" href="#252-installation">25.2 Installation</a></h2>
<p>You should make sure all the functions from the <code>Functions/Zftp</code>
directory of the source distribution are available; they all begin with
the two letters ‘<code>zf</code>’. They may already have been installed on your
system; otherwise, you will need to find them and copy them. The
directory should appear as one of the elements of the <code>$fpath</code> array
(this should already be the case if they were installed), and at least
the function <code>zfinit</code> should be autoloaded; it will autoload the rest.
Finally, to initialize the use of the system you need to call the
<code>zfinit</code> function. The following code in your <code>.zshrc</code> will arrange for
this; assume the functions are stored in the directory <code>~/myfns</code>:</p>
<div class="example">
<pre><code class="language-example">fpath=(~/myfns $fpath)
autoload -U zfinit
zfinit
</code></pre>
</div>
<p>Note that <code>zfinit</code> assumes you are using the <code>zmodload</code> method to load
the <code>zftp</code> command. If it is already built into the shell, change
<code>zfinit</code> to <code>zfinit -n</code>. It is helpful (though not essential) if the
call to <code>zfinit</code> appears after any code to initialize the new completion
system, else unnecessary <code>compctl</code> commands will be given.</p>
<hr />
<p><span id="Zftp-Functions"></span> <span id="Functions-2"></span></p>
<h2 id="253-functions"><a class="header" href="#253-functions">25.3 Functions</a></h2>
<p>The sequence of operations in performing a file transfer is essentially
the same as that in a standard FTP client. Note that, due to a quirk of
the shell’s <code>getopts</code> builtin, for those functions that handle options
you must use ‘<code>-``-</code>’ rather than ‘<code>-</code>’ to ensure the remaining
arguments are treated literally (a single ‘<code>-</code>’ is treated as an
argument).</p>
<hr />
<p><span id="Opening-a-connection"></span></p>
<h3 id="2531-opening-a-connection"><a class="header" href="#2531-opening-a-connection">25.3.1 Opening a connection</a></h3>
<p><span id="index-zfparams"></span></p>
<p><code>zfparams</code> [ <code>host</code> [ <code>user</code> [ <code>password</code> ... ] ] ]</p>
<p>Set or show the parameters for a future <code>zfopen</code> with no arguments. If
no arguments are given, the current parameters are displayed (the
password will be shown as a line of asterisks). If a <code>host</code> is given,
and either the <code>user</code> or <code>password</code> is not, they will be prompted for;
also, any parameter given as ‘<code>?</code>’ will be prompted for, and if the
‘<code>?</code>’ is followed by a string, that will be used as the prompt. As
<code>zfopen</code> calls <code>zfparams</code> to store the parameters, this usually need not
be called directly.</p>
<p>A single argument ‘<code>-</code>’ will delete the stored parameters. This will
also cause the memory of the last directory (and so on) on the other
host to be deleted.</p>
<p><span id="index-zfopen"></span></p>
<p><code>zfopen</code> [ <code>-1</code> ] [ <code>host</code> [ <code>user</code> [ <code>password</code> [ <code>account</code> ] ]
] ]</p>
<p>If <code>host</code> is present, open a connection to that host under username
<code>user</code> with password <code>password</code> (and, on the rare occasions when it is
necessary, account <code>account</code>). If a necessary parameter is missing or
given as ‘<code>?</code>’ it will be prompted for. If <code>host</code> is not present, use a
previously stored set of parameters.</p>
<p>If the command was successful, and the terminal is compatible with
<code>xterm</code> or is <code>sun-cmd</code>, a summary will appear in the title bar, giving
the local <code>host:directory</code> and the remote <code>host:directory</code>; this is
handled by the function <code>zftp_chpwd</code>, described below.</p>
<p>Normally, the <code>host</code>, <code>user</code> and <code>password</code> are internally recorded for
later re-opening, either by a <code>zfopen</code> with no arguments, or
automatically (see below). With the option ‘<code>-1</code>’, no information is
stored. Also, if an open command with arguments failed, the parameters
will not be retained (and any previous parameters will also be deleted).
A <code>zfopen</code> on its own, or a <code>zfopen -1</code>, never alters the stored
parameters.</p>
<p>Both <code>zfopen</code> and <code>zfanon</code> (but not <code>zfparams</code>) understand URLs of the
form <code>ftp://``host</code>/<code>path...</code> as meaning to connect to the <code>host</code>, then
change directory to <code>path</code> (which must be a directory, not a file). The
‘<code>ftp://</code>’ can be omitted; the trailing ‘<code>/</code>’ is enough to trigger
recognition of the <code>path</code>. Note prefixes other than ‘<code>ftp:</code>’ are not
recognized, and that all characters after the first slash beyond <code>host</code>
are significant in <code>path</code>.</p>
<p><span id="index-zfanon"></span></p>
<p><code>zfanon</code> [ <code>-1</code> ] <code>host</code></p>
<p>Open a connection <code>host</code> for anonymous FTP. The username used is
‘<code>anonymous</code>’. The password (which will be reported the first time) is
generated as <code>user``@``host</code>; this is then stored in the shell parameter
<code>$EMAIL_ADDR</code> which can alternatively be set manually to a</p>
<hr />
<p><span id="Directory-management"></span></p>
<h3 id="2532-directory-management"><a class="header" href="#2532-directory-management">25.3.2 Directory management</a></h3>
<p><span id="index-zfcd"></span></p>
<p><code>zfcd</code> [ <code>dir</code> ]</p>
<p><code>zfcd -</code></p>
<p><code>zfcd</code> <code>old</code> <code>new</code></p>
<p>Change the current directory on the remote server: this is implemented
to have many of the features of the shell builtin <code>cd</code>.</p>
<p>In the first form with <code>dir</code> present, change to the directory <code>dir</code>. The
command ‘<code>zfcd ..</code>’ is treated specially, so is guaranteed to work on
non-UNIX servers (note this is handled internally by <code>zftp</code>). If <code>dir</code>
is omitted, has the effect of ‘<code>zfcd ~</code>’.</p>
<p>The second form changes to the directory previously current.</p>
<p>The third form attempts to change the current directory by replacing the
first occurrence of the string <code>old</code> with the string <code>new</code> in the
current directory.</p>
<p>Note that in this command, and indeed anywhere a remote filename is
expected, the string which on the local host corresponds to ‘<code>~</code>’ is
converted back to a ‘<code>~</code>’ before being passed to the remote machine.
This is convenient because of the way expansion is performed on the
command line before <code>zfcd</code> receives a string. For example, suppose the
command is ‘<code>zfcd ~/foo</code>’. The shell will expand this to a full path
such as ‘<code>zfcd /home/user2/pws/foo</code>’. At this stage, <code>zfcd</code> recognises
the initial path as corresponding to ‘<code>~</code>’ and will send the directory
to the remote host as <code>~/foo</code>, so that the ‘<code>~</code>’ will be expanded by the
server to the correct remote host directory. Other named directories of
the form ‘<code>~name</code>’ are not treated in this fashion.</p>
<p><span id="index-zfhere"></span></p>
<p><code>zfhere</code></p>
<p>Change directory on the remote server to the one corresponding to the
current local directory, with special handling of ‘<code>~</code>’ as in <code>zfcd</code>.
For example, if the current local directory is <code>~/foo/bar</code>, then
<code>zfhere</code> performs the effect of ‘<code>zfcd ~/foo/bar</code>’.</p>
<p><span id="index-zfdir"></span></p>
<p><code>zfdir</code> [ <code>-rfd</code> ] [ <code>-</code> ] [ <code>dir-options</code> ] [ <code>dir</code> ]</p>
<p>Produce a long directory listing. The arguments <code>dir-options</code> and <code>dir</code>
are passed directly to the server and their effect is implementation
dependent, but specifying a particular remote directory <code>dir</code> is usually
possible. The output is passed through a pager given by the environment
variable <code>$PAGER</code>, or ‘<code>more</code>’ if that is not set.</p>
<p>The directory is usually cached for re-use. In fact, two caches are
maintained. One is for use when there is no <code>dir-options</code> or <code>dir</code>, i.e.
a full listing of the current remote directory; it is flushed when the
current remote directory changes. The other is kept for repeated use of
<code>zfdir</code> with the same arguments; for example, repeated use of ‘<code>zfdir /pub/gnu</code>’ will only require the directory to be retrieved on the first
call. Alternatively, this cache can be re-viewed with the <code>-r</code> option.
As relative directories will confuse <code>zfdir</code>, the <code>-f</code> option can be
used to force the cache to be flushed before the directory is listed.
The option <code>-d</code> will delete both caches without showing a directory
listing; it will also delete the cache of file names in the current
remote directory, if any.</p>
<p><span id="index-zfls"></span></p>
<p><code>zfls</code> [ <code>ls-options</code> ] [ <code>dir</code> ]</p>
<p>List files on the remote server. With no arguments, this will produce a
simple list of file names for the current remote directory. Any
arguments are passed directly to the server. No pager and no caching is
used.</p>
<hr />
<p><span id="Status-commands"></span></p>
<h3 id="2533-status-commands"><a class="header" href="#2533-status-commands">25.3.3 Status commands</a></h3>
<p><span id="index-zftype"></span></p>
<p><code>zftype</code> [ <code>type</code> ]</p>
<p>With no arguments, show the type of data to be transferred, usually
ASCII or binary. With an argument, change the type: the types ‘<code>A</code>’ or
‘<code>ASCII</code>’ for ASCII data and ‘<code>B</code>’ or ‘<code>BINARY</code>’, ‘<code>I</code>’ or ‘<code>IMAGE</code>’
for binary data are understood case-insensitively.</p>
<p><span id="index-zfstat"></span></p>
<p><code>zfstat</code> [ <code>-v</code> ]</p>
<p>Show the status of the current or last connection, as well as the status
of some of <code>zftp</code>’s status variables. With the <code>-v</code> option, a more
verbose listing is produced by querying the server for its version of
events, too.</p>
<hr />
<p><span id="Retrieving-files"></span></p>
<h3 id="2534-retrieving-files"><a class="header" href="#2534-retrieving-files">25.3.4 Retrieving files</a></h3>
<p>The commands for retrieving files all take at least two options. <code>-G</code>
suppresses remote filename expansion which would otherwise be performed
(see below for a more detailed description of that). <code>-t</code> attempts to
set the modification time of the local file to that of the remote file:
see the description of the function <code>zfrtime</code> below for more
information.</p>
<p><span id="index-zfget"></span></p>
<p><code>zfget</code> [ <code>-Gtc</code> ] <code>file1</code> ...</p>
<p>Retrieve all the listed files <code>file1</code> ... one at a time from the remote
server. If a file contains a ‘<code>/</code>’, the full name is passed to the
remote server, but the file is stored locally under the name given by
the part after the final ‘<code>/</code>’. The option <code>-c</code> (cat) forces all files
to be sent as a single stream to standard output; in this case the <code>-t</code>
option has no effect.</p>
<p><span id="index-zfuget"></span></p>
<p><code>zfuget</code> [ <code>-Gvst</code> ] <code>file1</code> ...</p>
<p>As <code>zfget</code>, but only retrieve files where the version on the remote
server is newer (has a later modification time), or where the local file
does not exist. If the remote file is older but the files have different
sizes, or if the sizes are the same but the remote file is newer, the
user will usually be queried. With the option <code>-s</code>, the command runs
silently and will always retrieve the file in either of those two cases.
With the option <code>-v</code>, the command prints more information about the
files while it is working out whether or not to transfer them.</p>
<p><span id="index-zfcget"></span></p>
<p><code>zfcget</code> [ <code>-Gt</code> ] <code>file1</code> ...</p>
<p>As <code>zfget</code>, but if any of the local files exists, and is shorter than
the corresponding remote file, the command assumes that it is the result
of a partially completed transfer and attempts to transfer the rest of
the file. This is useful on a poor connection which keeps failing.</p>
<p>Note that this requires a commonly implemented, but non-standard,
version of the FTP protocol, so is not guaranteed to work on all
servers.</p>
<p><span id="index-zfgcp"></span></p>
<p><code>zfgcp</code> [ <code>-Gt</code> ] <code>remote-file</code> <code>local-file</code></p>
<p><code>zfgcp</code> [ <code>-Gt</code> ] <code>rfile1</code> ... <code>ldir</code></p>
<p>This retrieves files from the remote server with arguments behaving
similarly to the <code>cp</code> command.</p>
<p>In the first form, copy <code>remote-file</code> from the server to the local file
<code>local-file</code>.</p>
<p>In the second form, copy all the remote files <code>rfile1</code> ... into the
local directory <code>ldir</code> retaining the same basenames. This assumes UNIX
directory semantics.</p>
<hr />
<p><span id="Sending-files"></span></p>
<h3 id="2535-sending-files"><a class="header" href="#2535-sending-files">25.3.5 Sending files</a></h3>
<p><span id="index-zfput"></span></p>
<p><code>zfput</code> [ <code>-r</code> ] <code>file1</code> ...</p>
<p>Send all the <code>file1</code> ... given separately to the remote server. If a
filename contains a ‘<code>/</code>’, the full filename is used locally to find the
file, but only the basename is used for the remote file name.</p>
<p>With the option <code>-r</code>, if any of the <code>files</code> are directories they are
sent recursively with all their subdirectories, including files
beginning with ‘<code>.</code>’. This requires that the remote machine understand
UNIX file semantics, since ‘<code>/</code>’ is used as a directory separator.</p>
<p><span id="index-zfuput"></span></p>
<p><code>zfuput</code> [ <code>-vs</code> ] <code>file1</code> ...</p>
<p>As <code>zfput</code>, but only send files which are newer than their remote
equivalents, or if the remote file does not exist. The logic is the same
as for <code>zfuget</code>, but reversed between local and remote files.</p>
<p><span id="index-zfcput"></span></p>
<p><code>zfcput</code> <code>file1</code> ...</p>
<p>As <code>zfput</code>, but if any remote file already exists and is shorter than
the local equivalent, assume it is the result of an incomplete transfer
and send the rest of the file to append to the existing part. As the FTP
append command is part of the standard set, this is in principle more
likely to work than <code>zfcget</code>.</p>
<p><span id="index-zfpcp"></span></p>
<p><code>zfpcp</code> <code>local-file</code> <code>remote-file</code></p>
<p><code>zfpcp</code> <code>lfile1</code> ... <code>rdir</code></p>
<p>This sends files to the remote server with arguments behaving similarly
to the <code>cp</code> command.</p>
<p>With two arguments, copy <code>local-file</code> to the server as <code>remote-file</code>.</p>
<p>With more than two arguments, copy all the local files <code>lfile1</code> ... into
the existing remote directory <code>rdir</code> retaining the same basenames. This
assumes UNIX directory semantics.</p>
<p>A problem arises if you attempt to use <code>zfpcp</code> <code>lfile1</code> <code>rdir</code>, i.e. the
second form of copying but with two arguments, as the command has no
simple way of knowing if <code>rdir</code> corresponds to a directory or a
filename. It attempts to resolve this in various ways. First, if the
<code>rdir</code> argument is ‘<code>.</code>’ or ‘<code>..</code>’ or ends in a slash, it is assumed to
be a directory. Secondly, if the operation of copying to a remote file
in the first form failed, and the remote server sends back the expected
failure code 553 and a reply including the string ‘<code>Is a directory</code>’,
then <code>zfpcp</code> will retry using the second form.</p>
<hr />
<p><span id="Closing-the-connection"></span></p>
<h3 id="2536-closing-the-connection"><a class="header" href="#2536-closing-the-connection">25.3.6 Closing the connection</a></h3>
<p><span id="index-zfclose"></span></p>
<p><code>zfclose</code></p>
<p>Close the connection.</p>
<hr />
<p><span id="Session-management"></span></p>
<h3 id="2537-session-management"><a class="header" href="#2537-session-management">25.3.7 Session management</a></h3>
<p><span id="index-zfsession"></span></p>
<p><code>zfsession</code> [ <code>-lvod</code> ] [ <code>sessname</code> ]</p>
<p>Allows you to manage multiple FTP sessions at once. By default,
connections take place in a session called ‘<code>default</code>’; by giving the
command ‘<code>zfsession</code> <code>sessname</code>’ you can change to a new or existing
session with a name of your choice. The new session remembers its own
connection, as well as associated shell parameters, and also the
host/user parameters set by <code>zfparams</code>. Hence you can have different
sessions set up to connect to different hosts, each remembering the
appropriate host, user and password.</p>
<p>With no arguments, <code>zfsession</code> prints the name of the current session;
with the option <code>-l</code> it lists all sessions which currently exist, and
with the option <code>-v</code> it gives a verbose list showing the host and
directory for each session, where the current session is marked with an
asterisk. With <code>-o</code>, it will switch to the most recent previous session.</p>
<p>With <code>-d</code>, the given session (or else the current one) is removed;
everything to do with it is completely forgotten. If it was the only
session, a new session called ‘<code>default</code>’ is created and made current.
It is safest not to delete sessions while background commands using
<code>zftp</code> are active.</p>
<p><span id="index-zftransfer"></span></p>
<p><code>zftransfer</code> <code>sess1``:``file1</code> <code>sess2``:``file2</code></p>
<p>Transfer files between two sessions; no local copy is made. The file is
read from the session <code>sess1</code> as <code>file1</code> and written to session <code>sess2</code>
as file <code>file2</code>; <code>file1</code> and <code>file2</code> may be relative to the current
directories of the session. Either <code>sess1</code> or <code>sess2</code> may be omitted
(though the colon should be retained if there is a possibility of a
colon appearing in the file name) and defaults to the current session;
<code>file2</code> may be omitted or may end with a slash, in which case the
basename of <code>file1</code> will be added. The sessions <code>sess1</code> and <code>sess2</code> must
be distinct.</p>
<p>The operation is performed using pipes, so it is required that the
connections still be valid in a subshell, which is not the case under
versions of some operating systems, presumably due to a system bug.</p>
<hr />
<p><span id="Bookmarks"></span></p>
<h3 id="2538-bookmarks"><a class="header" href="#2538-bookmarks">25.3.8 Bookmarks</a></h3>
<p>The two functions <code>zfmark</code> and <code>zfgoto</code> allow you to ‘bookmark’ the
present location (host, user and directory) of the current FTP
connection for later use. The file to be used for storing and retrieving
bookmarks is given by the parameter <code>$ZFTP_BMFILE</code>; if not set when one
of the two functions is called, it will be set to the file <code>.zfbkmarks</code>
in the directory where your zsh startup files live (usually <code>~</code>).</p>
<p><span id="index-zfmark"></span></p>
<p><code>zfmark</code> [ <code>bookmark</code> ]</p>
<p>If given an argument, mark the current host, user and directory under
the name <code>bookmark</code> for later use by <code>zfgoto</code>. If there is no connection
open, use the values for the last connection immediately before it was
closed; it is an error if there was none. Any existing bookmark under
the same name will be silently replaced.</p>
<p>If not given an argument, list the existing bookmarks and the points to
which they refer in the form <code>user``@``host``:``directory</code>; this is the
format in which they are stored, and the file may be edited directly.</p>
<p><span id="index-zfgoto"></span></p>
<p><code>zfgoto</code> [ <code>-n</code> ] <code>bookmark</code></p>
<p>Return to the location given by <code>bookmark</code>, as previously set by
<code>zfmark</code>. If the location has user ‘<code>ftp</code>’ or ‘<code>anonymous</code>’, open the
connection with <code>zfanon</code>, so that no password is required. If the user
and host parameters match those stored for the current session, if any,
those will be used, and again no password is required. Otherwise a
password will be prompted for.</p>
<p>With the option <code>-n</code>, the bookmark is taken to be a nickname stored by
the <code>ncftp</code> program in its bookmark file, which is assumed to be
<code>~/.ncftp/bookmarks</code>. The function works identically in other ways. Note
that there is no mechanism for adding or modifying <code>ncftp</code> bookmarks
from the zftp functions.</p>
<hr />
<p><span id="Other-functions"></span></p>
<h3 id="2539-other-functions"><a class="header" href="#2539-other-functions">25.3.9 Other functions</a></h3>
<p>Mostly, these functions will not be called directly (apart from
<code>zfinit</code>), but are described here for completeness. You may wish to
alter <code>zftp_chpwd</code> and <code>zftp_progress</code>, in particular.</p>
<p><span id="index-zfinit"></span></p>
<p><code>zfinit</code> [ <code>-n</code> ]</p>
<p>As described above, this is used to initialize the zftp function system.
The <code>-n</code> option should be used if the zftp command is already built into
the shell.</p>
<p><span id="index-zfautocheck"></span></p>
<p><code>zfautocheck</code> [ <code>-dn</code> ]</p>
<p>This function is called to implement automatic reopening behaviour, as
described in more detail below. The options must appear in the first
argument; <code>-n</code> prevents the command from changing to the old directory,
while <code>-d</code> prevents it from setting the variable <code>do_close</code>, which it
otherwise does as a flag for automatically closing the connection after
a transfer. The host and directory for the last session are stored in
the variable <code>$zflastsession</code>, but the internal host/user/password
parameters must also be correctly set.</p>
<p><span id="index-zfcd_005fmatch"></span></p>
<p><code>zfcd_match prefix suffix</code></p>
<p>This performs matching for completion of remote directory names. If the
remote server is UNIX, it will attempt to persuade the server to list
the remote directory with subdirectories marked, which usually works but
is not guaranteed. On other hosts it simply calls <code>zfget_match</code> and
hence completes all files, not just directories. On some systems,
directories may not even look like filenames.</p>
<p><span id="index-zfget_005fmatch"></span></p>
<p><code>zfget_match prefix suffix</code></p>
<p>This performs matching for completion of remote filenames. It caches
files for the current directory (only) in the shell parameter
<code>$zftp_fcache</code>. It is in the form to be called by the <code>-K</code> option of
<code>compctl</code>, but also works when called from a widget-style completion
function with <code>prefix</code> and <code>suffix</code> set appropriately.</p>
<p><span id="index-zfrglob"></span></p>
<p><code>zfrglob varname</code></p>
<p>Perform remote globbing, as describes in more detail below. <code>varname</code> is
the name of a variable containing the pattern to be expanded; if there
were any matches, the same variable will be set to the expanded set of
filenames on return.</p>
<p><span id="index-zfrtime"></span></p>
<p><code>zfrtime</code> <code>lfile</code> <code>rfile</code> [ <code>time</code> ]</p>
<p>Set the local file <code>lfile</code> to have the same modification time as the
remote file <code>rfile</code>, or the explicit time <code>time</code> in FTP format
<code>CCYYMMDDhhmmSS</code> for the GMT timezone. This uses the shell’s
<code>zsh/datetime</code> module to perform the conversion from GMT to local time.</p>
<p><span id="index-zftp_005fchpwd_002c-supplied-version"></span></p>
<p><code>zftp_chpwd</code></p>
<p>This function is called every time a connection is opened, or closed, or
the remote directory changes. This version alters the title bar of an
<code>xterm</code>-compatible or <code>sun-cmd</code> terminal emulator to reflect the local
and remote hostnames and current directories. It works best when
combined with the function <code>chpwd</code>. In particular, a function of the
form</p>
<div class="example">
<pre><code class="language-example">chpwd() {
if [[ -n $ZFTP_USER ]]; then
zftp_chpwd
else
# usual chpwd e.g put host:directory in title bar
fi
}
</code></pre>
</div>
<p>fits in well.</p>
<p><span id="index-zftp_005fprogress_002c-supplied-version"></span></p>
<p><code>zftp_progress</code></p>
<p>This function shows the status of the transfer. It will not write
anything unless the output is going to a terminal; however, if you
transfer files in the background, you should turn off progress reports
by hand using ‘<code>zstyle ’:zftp:*’ progress none</code>’. Note also that if you
alter it, any output <em>must</em> be to standard error, as standard output may
be a file being received. The form of the progress meter, or whether it
is used at all, can be configured without altering the function, as
described in the next section.</p>
<p><span id="index-zffcache"></span></p>
<p><code>zffcache</code></p>
<p>This is used to implement caching of files in the current directory for
each session separately. It is used by <code>zfget_match</code> and <code>zfrglob</code>.</p>
<hr />
<p><span id="Miscellaneous-Features"></span>
<span id="Miscellaneous-Features-1"></span></p>
<h2 id="254-miscellaneous-features"><a class="header" href="#254-miscellaneous-features">25.4 Miscellaneous Features</a></h2>
<hr />
<p><span id="Configuration-3"></span></p>
<h3 id="2541-configuration"><a class="header" href="#2541-configuration">25.4.1 Configuration</a></h3>
<p><span id="index-zftp-function-system_002c-configuration"></span>
<span id="index-zftp-function-system_002c-styles"></span>
<span id="index-styles-in-zftp-functions"></span></p>
<p>Various styles are available using the standard shell style mechanism,
described in <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a>. Briefly, the command
‘<code>zstyle ’:zftp:*’</code> <code>style</code> <code>value</code> ...’. defines the <code>style</code> to have
value <code>value</code>; more than one value may be given, although that is not
useful in the cases described here. These values will then be used
throughout the zftp function system. For more precise control, the first
argument, which gives a context in which the style applies, can be
modified to include a particular function, as for example
‘<code>:zftp:zfget</code>’: the style will then have the given value only in
the <code>zfget</code> function. Values for the same style in different contexts
may be set; the most specific function will be used, where strings are
held to be more specific than patterns, and longer patterns and shorter
patterns. Note that only the top level function name, as called by the
user, is used; calling of lower level functions is transparent to the
user. Hence modifications to the title bar in <code>zftp_chpwd</code> use the
contexts <code>:zftp:zfopen</code>, <code>:zftp:zfcd</code>, etc., depending where it was
called from. The following styles are understood:</p>
<p><span id="index-progress_002c-zftp-style"></span></p>
<p><code>progress</code></p>
<p>Controls the way that <code>zftp_progress</code> reports on the progress of a
transfer. If empty, unset, or ‘<code>none</code>’, no progress report is made; if
‘<code>bar</code>’ a growing bar of inverse video is shown; if ‘<code>percent</code>’ (or
any other string, though this may change in future), the percentage of
the file transferred is shown. The bar meter requires that the width of
the terminal be available via the <code>$COLUMNS</code> parameter (normally this is
set automatically). If the size of the file being transferred is not
available, <code>bar</code> and <code>percent</code> meters will simply show the number of
bytes transferred so far.</p>
<p>When <code>zfinit</code> is run, if this style is not defined for the context
<code>:zftp:*</code>, it will be set to ‘bar’.</p>
<p><span id="index-update_002c-zftp-style"></span></p>
<p><code>update</code></p>
<p>Specifies the minimum time interval between updates of the progress
meter in seconds. No update is made unless new data has been received,
so the actual time interval is limited only by <code>$ZFTP_TIMEOUT</code>.</p>
<p>As described for <code>progress</code>, <code>zfinit</code> will force this to default to 1.</p>
<p><span id="index-remote_002dglob_002c-zftp-style"></span></p>
<p><code>remote-glob</code></p>
<p>If set to ‘<code>1</code>’, ‘<code>yes</code>’ or ‘<code>true</code>’, filename generation (globbing) is
performed on the remote machine instead of by zsh itself; see below.</p>
<p><span id="index-titlebar_002c-zftp-style"></span></p>
<p><code>titlebar</code></p>
<p>If set to ‘<code>1</code>’, ‘<code>yes</code>’ or ‘<code>true</code>’, <code>zftp_chpwd</code> will put the remote
host and remote directory into the titlebar of terminal emulators such
as xterm or sun-cmd that allow this.</p>
<p>As described for <code>progress</code>, <code>zfinit</code> will force this to default to 1.</p>
<p><span id="index-chpwd_002c-zftp-style"></span></p>
<p><code>chpwd</code></p>
<p>If set to ‘<code>1</code>’ ‘<code>yes</code>’ or ‘<code>true</code>’, <code>zftp_chpwd</code> will call the function
<code>chpwd</code> when a connection is closed. This is useful if the remote host
details were put into the terminal title bar by <code>zftp_chpwd</code> and your
usual <code>chpwd</code> also modifies the title bar.</p>
<p>When <code>zfinit</code> is run, it will determine whether <code>chpwd</code> exists and if so
it will set the default value for the style to 1 if none exists already.</p>
<p>Note that there is also an associative array <code>zfconfig</code> which contains
values used by the function system. This should not be modified or
overwritten.</p>
<hr />
<p><span id="Remote-globbing"></span></p>
<h3 id="2542-remote-globbing"><a class="header" href="#2542-remote-globbing">25.4.2 Remote globbing</a></h3>
<p><span id="index-zftp-function-system_002c-remote-globbing"></span></p>
<p>The commands for retrieving files usually perform filename generation
(globbing) on their arguments; this can be turned off by passing the
option <code>-G</code> to each of the commands. Normally this operates by
retrieving a complete list of files for the directory in question, then
matching these locally against the pattern supplied. This has the
advantage that the full range of zsh patterns (respecting the setting of
the option <code>EXTENDED_GLOB</code>) can be used. However, it means that the
directory part of a filename will not be expanded and must be given
exactly. If the remote server does not support the UNIX directory
semantics, directory handling is problematic and it is recommended that
globbing only be used within the current directory. The list of files in
the current directory, if retrieved, will be cached, so that subsequent
globs in the same directory without an intervening <code>zfcd</code> are much
faster.</p>
<p>If the <code>remote-glob</code> style (see above) is set, globbing is instead
performed on the remote host: the server is asked for a list of matching
files. This is highly dependent on how the server is implemented, though
typically UNIX servers will provide support for basic glob patterns.
This may in some cases be faster, as it avoids retrieving the entire
list of directory contents.</p>
<hr />
<p><span id="Automatic-and-temporary-reopening"></span></p>
<h3 id="2543-automatic-and-temporary-reopening"><a class="header" href="#2543-automatic-and-temporary-reopening">25.4.3 Automatic and temporary reopening</a></h3>
<p><span id="index-zftp-function-system_002c-automatic-reopening"></span></p>
<p>As described for the <code>zfopen</code> command, a subsequent <code>zfopen</code> with no
parameters will reopen the connection to the last host (this includes
connections made with the <code>zfanon</code> command). Opened in this fashion, the
connection starts in the default remote directory and will remain open
until explicitly closed.</p>
<p>Automatic re-opening is also available. If a connection is not currently
open and a command requiring a connection is given, the last connection
is implicitly reopened. In this case the directory which was current
when the connection was closed again becomes the current directory
(unless, of course, the command given changes it). Automatic reopening
will also take place if the connection was close by the remote server
for whatever reason (e.g. a timeout). It is not available if the <code>-1</code>
option to <code>zfopen</code> or <code>zfanon</code> was used.</p>
<p>Furthermore, if the command issued is a file transfer, the connection
will be closed after the transfer is finished, hence providing a
one-shot mode for transfers. This does not apply to directory changing
or listing commands; for example a <code>zfdir</code> may reopen a connection but
will leave it open. Also, automatic closure will only ever happen in the
same command as automatic opening, i.e a <code>zfdir</code> directly followed by a
<code>zfget</code> will never close the connection automatically.</p>
<p>Information about the previous connection is given by the <code>zfstat</code>
function. So, for example, if that reports:</p>
<div class="example">
<pre><code class="language-example">Session: default
Not connected.
Last session: ftp.bar.com:/pub/textfiles
</code></pre>
</div>
<p>then the command <code>zfget file.txt</code> will attempt to reopen a connection to
<code>ftp.bar.com</code>, retrieve the file <code>/pub/textfiles/file.txt</code>, and
immediately close the connection again. On the other hand, <code>zfcd ..</code>
will open the connection in the directory <code>/pub</code> and leave it open.</p>
<p>Note that all the above is local to each session; if you return to a
previous session, the connection for that session is the one which will
be reopened.</p>
<hr />
<p><span id="Completion-3"></span></p>
<h3 id="2544-completion"><a class="header" href="#2544-completion">25.4.4 Completion</a></h3>
<p>Completion of local and remote files, directories, sessions and
bookmarks is supported. The older, <code>compctl</code>-style completion is defined
when <code>zfinit</code> is called; support for the new widget-based completion
system is provided in the function <code>Completion/Zsh/Command/_zftp</code>, which
should be installed with the other functions of the completion system
and hence should automatically be available.</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
<p><strong>Table of Contents</strong> <em>generated with <a href="https://github.com/thlorenz/doctoc">DocToc</a></em></p>
<ul>
<li><a href="User-Contributions.html#26-user-contributions">26 User Contributions</a>
<ul>
<li><a href="User-Contributions.html#261-description">26.1 Description</a></li>
<li><a href="User-Contributions.html#262-utilities">26.2 Utilities</a>
<ul>
<li><a href="User-Contributions.html#2621-accessing-on-line-help">26.2.1 Accessing On-Line Help</a></li>
<li><a href="User-Contributions.html#2622-recompiling-functions">26.2.2 Recompiling Functions</a></li>
<li><a href="User-Contributions.html#2623-keyboard-definition">26.2.3 Keyboard Definition</a></li>
<li><a href="User-Contributions.html#2624-dumping-shell-state">26.2.4 Dumping Shell State</a></li>
<li><a href="User-Contributions.html#2625-manipulating-hook-functions">26.2.5 Manipulating Hook Functions</a></li>
</ul>
</li>
<li><a href="User-Contributions.html#263-remembering-recent-directories">26.3 Remembering Recent Directories</a>
<ul>
<li><a href="User-Contributions.html#2631-installation">26.3.1 Installation</a></li>
<li><a href="User-Contributions.html#2632-use">26.3.2 Use</a></li>
<li><a href="User-Contributions.html#2633-options">26.3.3 Options</a></li>
<li><a href="User-Contributions.html#2634-configuration">26.3.4 Configuration</a></li>
<li><a href="User-Contributions.html#2635-use-with-dynamic-directory-naming">26.3.5 Use with dynamic directory naming</a></li>
<li><a href="User-Contributions.html#2636-details-of-directory-handling">26.3.6 Details of directory handling</a></li>
</ul>
</li>
<li><a href="User-Contributions.html#264-abbreviated-dynamic-references-to-directories">26.4 Abbreviated dynamic references to directories</a>
<ul>
<li><a href="User-Contributions.html#2641-usage">26.4.1 Usage</a></li>
<li><a href="User-Contributions.html#2642-configuration">26.4.2 Configuration</a></li>
<li><a href="User-Contributions.html#2643-complete-example">26.4.3 Complete example</a></li>
</ul>
</li>
<li><a href="User-Contributions.html#265-gathering-information-from-version-control-systems">26.5 Gathering information from version control systems</a>
<ul>
<li><a href="User-Contributions.html#2651-quickstart">26.5.1 Quickstart</a></li>
<li><a href="User-Contributions.html#2652-configuration">26.5.2 Configuration</a></li>
<li><a href="User-Contributions.html#2653-oddities">26.5.3 Oddities</a></li>
<li><a href="User-Contributions.html#2654-quilt-support">26.5.4 Quilt Support</a></li>
<li><a href="User-Contributions.html#2655-function-descriptions-public-api">26.5.5 Function Descriptions (Public API)</a></li>
<li><a href="User-Contributions.html#2656-variable-description">26.5.6 Variable Description</a></li>
<li><a href="User-Contributions.html#2657-hooks-in-vcs%5C_info">26.5.7 Hooks in vcs_info</a></li>
<li><a href="User-Contributions.html#2658-examples">26.5.8 Examples</a></li>
</ul>
</li>
<li><a href="User-Contributions.html#266-prompt-themes">26.6 Prompt Themes</a>
<ul>
<li><a href="User-Contributions.html#2661-installation">26.6.1 Installation</a></li>
<li><a href="User-Contributions.html#2662-theme-selection">26.6.2 Theme Selection</a></li>
<li><a href="User-Contributions.html#2663-utility-themes">26.6.3 Utility Themes</a></li>
<li><a href="User-Contributions.html#2664-writing-themes">26.6.4 Writing Themes</a></li>
</ul>
</li>
<li><a href="User-Contributions.html#267-zle-functions">26.7 ZLE Functions</a>
<ul>
<li><a href="User-Contributions.html#2671-widgets">26.7.1 Widgets</a></li>
<li><a href="User-Contributions.html#2672-utility-functions">26.7.2 Utility Functions</a></li>
<li><a href="User-Contributions.html#2673-styles">26.7.3 Styles</a></li>
</ul>
</li>
<li><a href="User-Contributions.html#268-exception-handling">26.8 Exception Handling</a></li>
<li><a href="User-Contributions.html#269-mime-functions">26.9 MIME Functions</a></li>
<li><a href="User-Contributions.html#2610-mathematical-functions">26.10 Mathematical Functions</a></li>
<li><a href="User-Contributions.html#2611-user-configuration-functions">26.11 User Configuration Functions</a></li>
<li><a href="User-Contributions.html#2612-other-functions">26.12 Other Functions</a>
<ul>
<li><a href="User-Contributions.html#26121-descriptions">26.12.1 Descriptions</a></li>
<li><a href="User-Contributions.html#26122-styles">26.12.2 Styles</a></li>
</ul>
</li>
</ul>
</li>
</ul>
<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<p><span id="User-Contributions"></span>
<span id="User-Contributions-1"></span></p>
<h1 id="26-user-contributions"><a class="header" href="#26-user-contributions">26 User Contributions</a></h1>
<p><span id="index-user-contributions"></span></p>
<hr />
<p><span id="Description-2"></span></p>
<h2 id="261-description"><a class="header" href="#261-description">26.1 Description</a></h2>
<p>The Zsh source distribution includes a number of items contributed by
the user community. These are not inherently a part of the shell, and
some may not be available in every zsh installation. The most
significant of these are documented here. For documentation on other
contributed items such as shell functions, look for comments in the
function source files.</p>
<hr />
<p><span id="Utilities"></span> <span id="Utilities-1"></span></p>
<h2 id="262-utilities"><a class="header" href="#262-utilities">26.2 Utilities</a></h2>
<hr />
<p><span id="Accessing-On_002dLine-Help"></span></p>
<h3 id="2621-accessing-on-line-help"><a class="header" href="#2621-accessing-on-line-help">26.2.1 Accessing On-Line Help</a></h3>
<p><span id="index-helpfiles-utility"></span></p>
<p>The key sequence <code>ESC h</code> is normally bound by ZLE to execute the
<code>run-help</code> widget (see <a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh Line
Editor</a>). This invokes the
<code>run-help</code> command with the command word from the current input line as
its argument. By default, <code>run-help</code> is an alias for the <code>man</code> command,
so this often fails when the command word is a shell builtin or a
user-defined function. By redefining the <code>run-help</code> alias, one can
improve the on-line help provided by the shell.</p>
<p>The <code>helpfiles</code> utility, found in the <code>Util</code> directory of the
distribution, is a Perl program that can be used to process the zsh
manual to produce a separate help file for each shell builtin and for
many other shell features as well. The autoloadable <code>run-help</code> function,
found in <code>Functions/Misc</code>, searches for these helpfiles and performs
several other tests to produce the most complete help possible for the
command.</p>
<p>Help files are installed by default to a subdirectory of
<code>/usr/share/zsh</code> or <code>/usr/local/share/zsh</code>.</p>
<p>To create your own help files with <code>helpfiles</code>, choose or create a
directory where the individual command help files will reside. For
example, you might choose <code>~/zsh_help</code>. If you unpacked the zsh
distribution in your home directory, you would use the commands:</p>
<div class="example">
<pre><code class="language-example">mkdir ~/zsh_help
perl ~/zsh-5.8/Util/helpfiles ~/zsh_help
</code></pre>
</div>
<p><span id="index-HELPDIR"></span></p>
<p>The <code>HELPDIR</code> parameter tells <code>run-help</code> where to look for the help
files. When unset, it uses the default installation path. To use your
own set of help files, set this to the appropriate path in one of your
startup files:</p>
<div class="example">
<pre><code class="language-example">HELPDIR=~/zsh_help
</code></pre>
</div>
<p><span id="index-run_002dhelp_002c-use-of"></span></p>
<p>To use the <code>run-help</code> function, you need to add lines something like the
following to your <code>.zshrc</code> or equivalent startup file:</p>
<div class="example">
<pre><code class="language-example">unalias run-help
autoload run-help
</code></pre>
</div>
<p>Note that in order for ‘<code>autoload run-help</code>’ to work, the <code>run-help</code>
file must be in one of the directories named in your <code>fpath</code> array (see
<a href="Parameters.html#Parameters-Used-By-The-Shell">Parameters Used By The
Shell</a>). This should
already be the case if you have a standard zsh installation; if it is
not, copy <code>Functions/Misc/run-help</code> to an appropriate directory.</p>
<hr />
<p><span id="Recompiling-Functions"></span></p>
<h3 id="2622-recompiling-functions"><a class="header" href="#2622-recompiling-functions">26.2.2 Recompiling Functions</a></h3>
<p><span id="index-functions_002c-recompiling"></span>
<span id="index-zrecompile-utility"></span></p>
<p>If you frequently edit your zsh functions, or periodically update your
zsh installation to track the latest developments, you may find that
function digests compiled with the <code>zcompile</code> builtin are frequently out
of date with respect to the function source files. This is not usually a
problem, because zsh always looks for the newest file when loading a
function, but it may cause slower shell startup and function loading.
Also, if a digest file is explicitly used as an element of <code>fpath</code>, zsh
won’t check whether any of its source files has changed.</p>
<p>The <code>zrecompile</code> autoloadable function, found in <code>Functions/Misc</code>, can
be used to keep function digests up to date.</p>
<p><span id="index-zrecompile"></span></p>
<p><code>zrecompile</code> [ <code>-qt</code> ] [ <code>name</code> ... ]</p>
<p><code>zrecompile</code> [ <code>-qt</code> ] <code>-p</code> <code>arg</code> ... [ <code>-``-</code> <code>arg</code> ... ]</p>
<p>This tries to find <code>*.zwc</code> files and automatically re-compile them if at
least one of the original files is newer than the compiled file. This
works only if the names stored in the compiled files are full paths or
are relative to the directory that contains the <code>.zwc</code> file.</p>
<p>In the first form, each <code>name</code> is the name of a compiled file or a
directory containing <code>*.zwc</code> files that should be checked. If no
arguments are given, the directories and <code>*.zwc</code> files in <code>fpath</code> are
used.</p>
<p>When <code>-t</code> is given, no compilation is performed, but a return status of
zero (true) is set if there are files that need to be re-compiled and
non-zero (false) otherwise. The <code>-q</code> option quiets the chatty output
that describes what <code>zrecompile</code> is doing.</p>
<p>Without the <code>-t</code> option, the return status is zero if all files that
needed re-compilation could be compiled and non-zero if compilation for
at least one of the files failed.</p>
<p>If the <code>-p</code> option is given, the <code>arg</code>s are interpreted as one or more
sets of arguments for <code>zcompile</code>, separated by ‘<code>-``-</code>’. For example:</p>
<div class="example">
<pre><code class="language-example">zrecompile -p \
-R ~/.zshrc -- \
-M ~/.zcompdump -- \
~/zsh/comp.zwc ~/zsh/Completion/*/_*
</code></pre>
</div>
<p>This compiles <code>~/.zshrc</code> into <code>~/.zshrc.zwc</code> if that doesn’t exist or if
it is older than <code>~/.zshrc</code>. The compiled file will be marked for
reading instead of mapping. The same is done for <code>~/.zcompdump</code> and
<code>~/.zcompdump.zwc</code>, but this compiled file is marked for mapping. The
last line re-creates the file <code>~/zsh/comp.zwc</code> if any of the files
matching the given pattern is newer than it.</p>
<p>Without the <code>-p</code> option, <code>zrecompile</code> does not create function digests
that do not already exist, nor does it add new functions to the digest.</p>
<p>The following shell loop is an example of a method for creating function
digests for all functions in your <code>fpath</code>, assuming that you have write
permission to the directories:</p>
<div class="example">
<pre><code class="language-example">for ((i=1; i &lt;= $#fpath; ++i)); do
dir=$fpath[i]
zwc=${dir:t}.zwc
if [[ $dir == (.|..) || $dir == (.|..)/* ]]; then
continue
fi
files=($dir/*(N-.))
if [[ -w $dir:h &amp;&amp; -n $files ]]; then
files=(${${(M)files%/*/*}#/})
if ( cd $dir:h &amp;&amp;
zrecompile -p -U -z $zwc $files ); then
fpath[i]=$fpath[i].zwc
fi
fi
done
</code></pre>
</div>
<p>The <code>-U</code> and <code>-z</code> options are appropriate for functions in the default
zsh installation <code>fpath</code>; you may need to use different options for your
personal function directories.</p>
<p>Once the digests have been created and your <code>fpath</code> modified to refer to
them, you can keep them up to date by running <code>zrecompile</code> with no
arguments.</p>
<hr />
<p><span id="Keyboard-Definition"></span></p>
<h3 id="2623-keyboard-definition"><a class="header" href="#2623-keyboard-definition">26.2.3 Keyboard Definition</a></h3>
<p><span id="index-keyboard-definition"></span>
<span id="index-zkbd"></span></p>
<p>The large number of possible combinations of keyboards, workstations,
terminals, emulators, and window systems makes it impossible for zsh to
have built-in key bindings for every situation. The <code>zkbd</code> utility,
found in <code>Functions/Misc</code>, can help you quickly create key bindings for
your configuration.</p>
<p>Run <code>zkbd</code> either as an autoloaded function, or as a shell script:</p>
<div class="example">
<pre><code class="language-example">zsh -f ~/zsh-5.8/Functions/Misc/zkbd
</code></pre>
</div>
<p>When you run <code>zkbd</code>, it first asks you to enter your terminal type; if
the default it offers is correct, just press return. It then asks you to
press a number of different keys to determine characteristics of your
keyboard and terminal; <code>zkbd</code> warns you if it finds anything out of the
ordinary, such as a Delete key that sends neither <code>^H</code> nor <code>^?</code>.</p>
<p>The keystrokes read by <code>zkbd</code> are recorded as a definition for an
associative array named <code>key</code>, written to a file in the subdirectory
<code>.zkbd</code> within either your <code>HOME</code> or <code>ZDOTDIR</code> directory. The name of
the file is composed from the <code>TERM</code>, <code>VENDOR</code> and <code>OSTYPE</code> parameters,
joined by hyphens.</p>
<p>You may read this file into your <code>.zshrc</code> or another startup file with
the ‘<code>source</code>’ or ‘<code>.</code>’ commands, then reference the <code>key</code> parameter in
bindkey commands, like this:</p>
<div class="example">
<pre><code class="language-example">source ${ZDOTDIR:-$HOME}/.zkbd/$TERM-$VENDOR-$OSTYPE
[[ -n ${key[Left]} ]] &amp;&amp; bindkey &quot;${key[Left]}&quot; backward-char
[[ -n ${key[Right]} ]] &amp;&amp; bindkey &quot;${key[Right]}&quot; forward-char
# etc.
</code></pre>
</div>
<p>Note that in order for ‘<code>autoload zkbd</code>’ to work, the <code>zkdb</code> file must
be in one of the directories named in your <code>fpath</code> array (see
<a href="Parameters.html#Parameters-Used-By-The-Shell">Parameters Used By The
Shell</a>). This should
already be the case if you have a standard zsh installation; if it is
not, copy <code>Functions/Misc/zkbd</code> to an appropriate directory.</p>
<hr />
<p><span id="Dumping-Shell-State"></span></p>
<h3 id="2624-dumping-shell-state"><a class="header" href="#2624-dumping-shell-state">26.2.4 Dumping Shell State</a></h3>
<p><span id="index-reporter-utility"></span></p>
<p>Occasionally you may encounter what appears to be a bug in the shell,
particularly if you are using a beta version of zsh or a development
release. Usually it is sufficient to send a description of the problem
to one of the zsh mailing lists (see <a href="Introduction.html#Mailing-Lists">Mailing
Lists</a>), but sometimes one of the zsh
developers will need to recreate your environment in order to track the
problem down.</p>
<p>The script named <code>reporter</code>, found in the <code>Util</code> directory of the
distribution, is provided for this purpose. (It is also possible to
<code>autoload reporter</code>, but <code>reporter</code> is not installed in <code>fpath</code> by
default.) This script outputs a detailed dump of the shell state, in the
form of another script that can be read with ‘<code>zsh -f</code>’ to recreate that
state.</p>
<p>To use <code>reporter</code>, read the script into your shell with the ‘<code>.</code>’
command and redirect the output into a file:</p>
<div class="example">
<pre><code class="language-example">. ~/zsh-5.8/Util/reporter &gt; zsh.report
</code></pre>
</div>
<p>You should check the <code>zsh.report</code> file for any sensitive information
such as passwords and delete them by hand before sending the script to
the developers. Also, as the output can be voluminous, it’s best to wait
for the developers to ask for this information before sending it.</p>
<p>You can also use <code>reporter</code> to dump only a subset of the shell state.
This is sometimes useful for creating startup files for the first time.
Most of the output from reporter is far more detailed than usually is
necessary for a startup file, but the <code>aliases</code>, <code>options</code>, and
<code>zstyles</code> states may be useful because they include only changes from
the defaults. The <code>bindings</code> state may be useful if you have created any
of your own keymaps, because <code>reporter</code> arranges to dump the keymap
creation commands as well as the bindings for every keymap.</p>
<p>As is usual with automated tools, if you create a startup file with
<code>reporter</code>, you should edit the results to remove unnecessary commands.
Note that if you’re using the new completion system, you should <em>not</em>
dump the <code>functions</code> state to your startup files with <code>reporter</code>; use
the <code>compdump</code> function instead (see <a href="Completion-System.html#Completion-System">Completion
System</a>).</p>
<ul>
<li>
<p><code>reporter</code> [ <code>state</code> ... ]<br />
<span id="index-reporter"></span></p>
<p>Print to standard output the indicated subset of the current shell
state. The <code>state</code> arguments may be one or more of:</p>
<ul>
<li>
<p><code>all</code><br />
Output everything listed below.</p>
</li>
<li>
<p><code>aliases</code><br />
Output alias definitions.</p>
</li>
<li>
<p><code>bindings</code><br />
Output ZLE key maps and bindings.</p>
</li>
<li>
<p><code>completion</code><br />
Output old-style <code>compctl</code> commands. New completion is covered
by <code>functions</code> and <code>zstyles</code>.</p>
</li>
<li>
<p><code>functions</code><br />
Output autoloads and function definitions.</p>
</li>
<li>
<p><code>limits</code><br />
Output <code>limit</code> commands.</p>
</li>
<li>
<p><code>options</code><br />
Output <code>setopt</code> commands.</p>
</li>
<li>
<p><code>styles</code><br />
Same as <code>zstyles</code>.</p>
</li>
<li>
<p><code>variables</code><br />
Output shell parameter assignments, plus <code>export</code> commands for
any environment variables.</p>
</li>
<li>
<p><code>zstyles</code><br />
Output <code>zstyle</code> commands.</p>
</li>
</ul>
<p>If the <code>state</code> is omitted, <code>all</code> is assumed.</p>
<p>With the exception of ‘<code>all</code>’, every <code>state</code> can be abbreviated by
any prefix, even a single letter; thus <code>a</code> is the same as <code>aliases</code>,
<code>z</code> is the same as <code>zstyles</code>, etc.</p>
</li>
</ul>
<hr />
<p><span id="Manipulating-Hook-Functions"></span></p>
<h3 id="2625-manipulating-hook-functions"><a class="header" href="#2625-manipulating-hook-functions">26.2.5 Manipulating Hook Functions</a></h3>
<p><span id="index-hook-function-utility"></span></p>
<p><span id="index-add_002dzsh_002dhook"></span></p>
<p><code>add-zsh-hook</code> [ <code>-L</code> | <code>-dD</code> ] [ <code>-Uzk</code> ] <code>hook</code> <code>function</code></p>
<p>Several functions are special to the shell, as described in the section
Special Functions, <a href="Functions.html#Functions">Functions</a>, in that they
are automatically called at specific points during shell execution. Each
has an associated array consisting of names of functions to be called at
the same point; these are so-called ‘hook functions’. The shell function
<code>add-zsh-hook</code> provides a simple way of adding or removing functions
from the array.</p>
<p><code>hook</code> is one of <code>chpwd</code>, <code>periodic</code>, <code>precmd</code>, <code>preexec</code>,
<code>zshaddhistory</code>, <code>zshexit</code>, or <code>zsh_directory_name</code>, the special
functions in question. Note that <code>zsh_directory_name</code> is called in a
different way from the other functions, but may still be manipulated as
a hook.</p>
<p><code>function</code> is name of an ordinary shell function. If no options are
given this will be added to the array of functions to be executed in the
given context. Functions are invoked in the order they were added.</p>
<p>If the option <code>-L</code> is given, the current values for the hook arrays are
listed with <code>typeset</code>.</p>
<p>If the option <code>-d</code> is given, the <code>function</code> is removed from the array of
functions to be executed.</p>
<p>If the option <code>-D</code> is given, the <code>function</code> is treated as a pattern and
any matching names of functions are removed from the array of functions
to be executed.</p>
<p>The options <code>-U</code>, <code>-z</code> and <code>-k</code> are passed as arguments to <code>autoload</code>
for <code>function</code>. For functions contributed with zsh, the options <code>-Uz</code>
are appropriate.</p>
<p><span id="index-add_002dzle_002dhook_002dwidget"></span></p>
<p><code>add-zle-hook-widget</code> [ <code>-L</code> | <code>-dD</code> ] [ <code>-Uzk</code> ] <code>hook</code>
<code>widgetname</code></p>
<p>Several widget names are special to the line editor, as described in the
section Special Widgets, <a href="Zsh-Line-Editor.html#Zle-Widgets">Widgets</a>, in
that they are automatically called at specific points during editing.
Unlike function hooks, these do not use a predefined array of other
names to call at the same point; the shell function
<code>add-zle-hook-widget</code> maintains a similar array and arranges for the
special widget to invoke those additional widgets.</p>
<p><code>hook</code> is one of <code>isearch-exit</code>, <code>isearch-update</code>, <code>line-pre-redraw</code>,
<code>line-init</code>, <code>line-finish</code>, <code>history-line-set</code>, or <code>keymap-select</code>,
corresponding to each of the special widgets <code>zle-isearch-exit</code>, etc.
The special widget names are also accepted as the <code>hook</code> argument.</p>
<p><code>widgetname</code> is the name of a ZLE widget. If no options are given this
is added to the array of widgets to be invoked in the given hook
context. Widgets are invoked in the order they were added, with</p>
<div class="example">
<pre><code class="language-example">zle widgetname -Nw -- &quot;$@&quot;
</code></pre>
</div>
<p><span id="index-WIDGET_002c-in-hooks"></span></p>
<p>Note that this means that the ‘<code>WIDGET</code>’ special parameter tracks the
<code>widgetname</code> when the widget function is called, rather than tracking
the name of the corresponding special hook widget.</p>
<p>If the option <code>-d</code> is given, the <code>widgetname</code> is removed from the array
of widgets to be executed.</p>
<p>If the option <code>-D</code> is given, the <code>widgetname</code> is treated as a pattern
and any matching names of widgets are removed from the array.</p>
<p>If <code>widgetname</code> does not name an existing widget when added to the
array, it is assumed that a shell function also named <code>widgetname</code> is
meant to provide the implementation of the widget. This name is
therefore marked for autoloading, and the options <code>-U</code>, <code>-z</code> and <code>-k</code>
are passed as arguments to <code>autoload</code> as with <code>add-zsh-hook</code>. The widget
is also created with ‘<code> zle -N ``widgetname</code>’ to cause the
corresponding function to be loaded the first time the hook is called.</p>
<p>The arrays of <code>widgetname</code> are currently maintained in <code>zstyle</code>
contexts, one for each <code>hook</code> context, with a style of ‘<code>widgets</code>’. If
the <code>-L</code> option is given, this set of styles is listed with ‘<code>zstyle -L</code>’. This implementation may change, and the special widgets that
refer to the styles are created only if <code>add-zle-hook-widget</code> is called
to add at least one widget, so if this function is used for any hooks,
then all hooks should be managed only via this function.</p>
<hr />
<p><span id="Recent-Directories"></span>
<span id="index-recent-directories_002c-maintaining-list-of"></span>
<span id="index-directories_002c-maintaining-list-of-recent"></span>
<span id="index-cdr"></span> <span id="index-_005fcdr"></span>
<span id="index-chpwd_005frecent_005fadd"></span>
<span id="index-chpwd_005frecent_005fdirs"></span>
<span id="index-chpwd_005frecent_005ffilehandler"></span>
<span id="Remembering-Recent-Directories"></span></p>
<h2 id="263-remembering-recent-directories"><a class="header" href="#263-remembering-recent-directories">26.3 Remembering Recent Directories</a></h2>
<p>The function <code>cdr</code> allows you to change the working directory to a
previous working directory from a list maintained automatically. It is
similar in concept to the directory stack controlled by the <code>pushd</code>,
<code>popd</code> and <code>dirs</code> builtins, but is more configurable, and as it stores
all entries in files it is maintained across sessions and (by default)
between terminal emulators in the current session. Duplicates are
automatically removed, so that the list reflects the single most recent
use of each directory.</p>
<p>Note that the <code>pushd</code> directory stack is not actually modified or used
by <code>cdr</code> unless you configure it to do so as described in the
configuration section below.</p>
<hr />
<p><span id="Installation-3"></span></p>
<h3 id="2631-installation"><a class="header" href="#2631-installation">26.3.1 Installation</a></h3>
<p>The system works by means of a hook function that is called every time
the directory changes. To install the system, autoload the required
functions and use the <code>add-zsh-hook</code> function described above:</p>
<div class="example">
<pre><code class="language-example">autoload -Uz chpwd_recent_dirs cdr add-zsh-hook
add-zsh-hook chpwd chpwd_recent_dirs
</code></pre>
</div>
<p>Now every time you change directly interactively, no matter which
command you use, the directory to which you change will be remembered in
most-recent-first order.</p>
<hr />
<p><span id="Use"></span></p>
<h3 id="2632-use"><a class="header" href="#2632-use">26.3.2 Use</a></h3>
<p>All direct user interaction is via the <code>cdr</code> function.</p>
<p>The argument to cdr is a number <code>N</code> corresponding to the <code>N</code>th most
recently changed-to directory. 1 is the immediately preceding directory;
the current directory is remembered but is not offered as a destination.
Note that if you have multiple windows open 1 may refer to a directory
changed to in another window; you can avoid this by having per-terminal
files for storing directory as described for the <code>recent-dirs-file</code>
style below.</p>
<p>If you set the <code>recent-dirs-default</code> style described below <code>cdr</code> will
behave the same as <code>cd</code> if given a non-numeric argument, or more than
one argument. The recent directory list is updated just the same however
you change directory.</p>
<p>If the argument is omitted, 1 is assumed. This is similar to <code>pushd</code>’s
behaviour of swapping the two most recent directories on the stack.</p>
<p>Completion for the argument to <code>cdr</code> is available if compinit has been
run; menu selection is recommended, using:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*:*:cdr:*:*' menu selection
</code></pre>
</div>
<p>to allow you to cycle through recent directories; the order is
preserved, so the first choice is the most recent directory before the
current one. The verbose style is also recommended to ensure the
directory is shown; this style is on by default so no action is required
unless you have changed it.</p>
<hr />
<p><span id="Options-2"></span></p>
<h3 id="2633-options"><a class="header" href="#2633-options">26.3.3 Options</a></h3>
<p>The behaviour of <code>cdr</code> may be modified by the following options.</p>
<ul>
<li>
<p><code>-l</code><br />
lists the numbers and the corresponding directories in abbreviated
form (i.e. with <code>~</code> substitution reapplied), one per line. The
directories here are not quoted (this would only be an issue if a
directory name contained a newline). This is used by the completion
system.</p>
</li>
<li>
<p><code>-r</code><br />
sets the variable <code>reply</code> to the current set of directories. Nothing
is printed and the directory is not changed.</p>
</li>
<li>
<p><code>-e</code><br />
allows you to edit the list of directories, one per line. The list
can be edited to any extent you like; no sanity checking is
performed. Completion is available. No quoting is necessary (except
for newlines, where I have in any case no sympathy); directories are
in unabbreviated from and contain an absolute path, i.e. they start
with <code>/</code>. Usually the first entry should be left as the current
directory.</p>
</li>
<li>
<p><code>-p ’``pattern``’</code><br />
Prunes any items in the directory list that match the given extended
glob pattern; the pattern needs to be quoted from immediate
expansion on the command line. The pattern is matched against each
completely expanded file name in the list; the full string must
match, so wildcards at the end (e.g. <code>’*removeme*’</code>) are needed to
remove entries with a given substring.</p>
<p>If output is to a terminal, then the function will print the new
list after pruning and prompt for confirmation by the user. This
output and confirmation step can be skipped by using <code>-P</code> instead of
<code>-p</code>.</p>
</li>
</ul>
<hr />
<p><span id="Configuration-2"></span></p>
<h3 id="2634-configuration"><a class="header" href="#2634-configuration">26.3.4 Configuration</a></h3>
<p>Configuration is by means of the styles mechanism that should be
familiar from completion; if not, see the description of the <code>zstyle</code>
command in <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a>. The context for
setting styles should be <code>’:chpwd:*’</code> in case the meaning of the context
is extended in future, for example:</p>
<div class="example">
<pre><code class="language-example">zstyle ':chpwd:*' recent-dirs-max 0
</code></pre>
</div>
<p>sets the value of the <code>recent-dirs-max</code> style to 0. In practice the
style name is specific enough that a context of ’*’ should be fine.</p>
<p>An exception is <code>recent-dirs-insert</code>, which is used exclusively by the
completion system and so has the usual completion system context
(<code>’:completion:*’</code> if nothing more specific is needed), though again
<code>’*’</code> should be fine in practice.</p>
<ul>
<li>
<p><code>recent-dirs-default</code><br />
If true, and the command is expecting a recent directory index, and
either there is more than one argument or the argument is not an
integer, then fall through to &quot;cd&quot;. This allows the lazy to use only
one command for directory changing. Completion recognises this, too;
see recent-dirs-insert for how to control completion when this
option is in use.</p>
</li>
<li>
<p><code>recent-dirs-file</code><br />
The file where the list of directories is saved. The default is
<code>${ZDOTDIR:-$HOME}/.chpwd-recent-dirs</code>, i.e. this is in your home
directory unless you have set the variable <code>ZDOTDIR</code> to point
somewhere else. Directory names are saved in <code>$’``...``’</code> quoted
form, so each line in the file can be supplied directly to the shell
as an argument.</p>
<p>The value of this style may be an array. In this case, the first
file in the list will always be used for saving directories while
any other files are left untouched. When reading the recent
directory list, if there are fewer than the maximum number of
entries in the first file, the contents of later files in the array
will be appended with duplicates removed from the list shown. The
contents of the two files are not sorted together, i.e. all the
entries in the first file are shown first. The special value <code>+</code> can
appear in the list to indicate the default file should be read at
that point. This allows effects like the following:</p>
<div class="example">
<pre><code class="language-example">zstyle ':chpwd:*' recent-dirs-file \
~/.chpwd-recent-dirs-${TTY##*/} +
</code></pre>
</div>
<p>Recent directories are read from a file numbered according to the
terminal. If there are insufficient entries the list is supplemented
from the default file.</p>
<p>It is possible to use <code>zstyle -e</code> to make the directory configurable
at run time:</p>
<div class="example">
<pre><code class="language-example">zstyle -e ':chpwd:*' recent-dirs-file pick-recent-dirs-file
pick-recent-dirs-file() {
if [[ $PWD = ~/text/writing(|/*) ]]; then
reply=(~/.chpwd-recent-dirs-writing)
else
reply=(+)
fi
}
</code></pre>
</div>
<p>In this example, if the current directory is <code>~/text/writing</code> or a
directory under it, then use a special file for saving recent
directories, else use the default.</p>
</li>
<li>
<p><code>recent-dirs-insert</code><br />
Used by completion. If <code>recent-dirs-default</code> is true, then setting
this to <code>true</code> causes the actual directory, rather than its index,
to be inserted on the command line; this has the same effect as
using the corresponding index, but makes the history clearer and the
line easier to edit. With this setting, if part of an argument was
already typed, normal directory completion rather than recent
directory completion is done; this is because recent directory
completion is expected to be done by cycling through entries menu
fashion.</p>
<p>If the value of the style is <code>always</code>, then only recent directories
will be completed; in that case, use the <code>cd</code> command when you want
to complete other directories.</p>
<p>If the value is <code>fallback</code>, recent directories will be tried first,
then normal directory completion is performed if recent directory
completion failed to find a match.</p>
<p>Finally, if the value is <code>both</code> then both sets of completions are
presented; the usual tag mechanism can be used to distinguish
results, with recent directories tagged as <code>recent-dirs</code>. Note that
the recent directories inserted are abbreviated with directory names
where appropriate.</p>
</li>
<li>
<p><code>recent-dirs-max</code><br />
The maximum number of directories to save to the file. If this is
zero or negative there is no maximum. The default is 20. Note this
includes the current directory, which isn’t offered, so the highest
number of directories you will be offered is one less than the
maximum.</p>
</li>
<li>
<p><code>recent-dirs-prune</code><br />
This style is an array determining what directories should (or
should not) be added to the recent list. Elements of the array can
include:</p>
<ul>
<li>
<p><code>parent</code><br />
Prune parents (more accurately, ancestors) from the recent list.
If present, changing directly down by any number of directories
causes the current directory to be overwritten. For example,
changing from ~pws to ~pws/some/other/dir causes ~pws not to
be left on the recent directory stack. This only applies to
direct changes to descendant directories; earlier directories on
the list are not pruned. For example, changing from
~pws/yet/another to ~pws/some/other/dir does not cause ~pws
to be pruned.</p>
</li>
<li>
<p><code>pattern:pattern</code><br />
Gives a zsh pattern for directories that should not be added to
the recent list (if not already there). This element can be
repeated to add different patterns. For example,
<code>’pattern:/tmp(|/*)’</code> stops <code>/tmp</code> or its descendants from
being added. The <code>EXTENDED_GLOB</code> option is always turned on for
these patterns.</p>
</li>
</ul>
</li>
<li>
<p><code>recent-dirs-pushd</code><br />
If set to true, <code>cdr</code> will use <code>pushd</code> instead of <code>cd</code> to change the
directory, so the directory is saved on the directory stack. As the
directory stack is completely separate from the list of files saved
by the mechanism used in this file there is no obvious reason to do
this.</p>
</li>
</ul>
<hr />
<p><span id="Use-with-dynamic-directory-naming"></span></p>
<h3 id="2635-use-with-dynamic-directory-naming"><a class="header" href="#2635-use-with-dynamic-directory-naming">26.3.5 Use with dynamic directory naming</a></h3>
<p>It is possible to refer to recent directories using the dynamic
directory name syntax by using the supplied function
<code>zsh_directory_name_cdr</code> a hook:</p>
<div class="example">
<pre><code class="language-example">autoload -Uz add-zsh-hook
add-zsh-hook -Uz zsh_directory_name zsh_directory_name_cdr
</code></pre>
</div>
<p>When this is done, <code>~[1]</code> will refer to the most recent directory other
than $PWD, and so on. Completion after <code>~[``...</code> also works.</p>
<hr />
<p><span id="Details-of-directory-handling"></span></p>
<h3 id="2636-details-of-directory-handling"><a class="header" href="#2636-details-of-directory-handling">26.3.6 Details of directory handling</a></h3>
<p>This section is for the curious or confused; most users will not need to
know this information.</p>
<p>Recent directories are saved to a file immediately and hence are
preserved across sessions. Note currently no file locking is applied:
the list is updated immediately on interactive commands and nowhere else
(unlike history), and it is assumed you are only going to change
directory in one window at once. This is not safe on shared accounts,
but in any case the system has limited utility when someone else is
changing to a different set of directories behind your back.</p>
<p>To make this a little safer, only directory changes instituted from the
command line, either directly or indirectly through shell function calls
(but not through subshells, evals, traps, completion functions and the
like) are saved. Shell functions should use <code>cd -q</code> or <code>pushd -q</code> to
avoid side effects if the change to the directory is to be invisible at
the command line. See the contents of the function <code>chpwd_recent_dirs</code>
for more details.</p>
<hr />
<p><span id="Other-Directory-Functions"></span>
<span id="index-directories_002c-named_002c-dynamic_002c-helper-function"></span>
<span id="index-dynamic-directory-naming_002c-helper-function"></span>
<span id="index-named-directories_002c-dynamic_002c-helper-function"></span>
<span id="index-zsh_005fdirectory_005fname_005fgeneric"></span>
<span id="Abbreviated-dynamic-references-to-directories"></span></p>
<h2 id="264-abbreviated-dynamic-references-to-directories"><a class="header" href="#264-abbreviated-dynamic-references-to-directories">26.4 Abbreviated dynamic references to directories</a></h2>
<p>The dynamic directory naming system is described in the subsection
<em>Dynamic named directories</em> of <a href="Expansion.html#Filename-Expansion">Filename
Expansion</a>. In this, a reference to
<code>~[``...``]</code> is expanded by a function found by the hooks mechanism.</p>
<p>The contributed function <code>zsh_directory_name_generic</code> provides a system
allowing the user to refer to directories with only a limited amount of
new code. It supports all three of the standard interfaces for directory
naming: converting from a name to a directory, converting in the reverse
direction to find a short name, and completion of names.</p>
<p>The main feature of this function is a path-like syntax, combining
abbreviations at multiple levels separated by &quot;:&quot;. As an example,
~[g:p:s] might specify:</p>
<ul>
<li>
<p><code>g</code><br />
The top level directory for your git area. This first component has
to match, or the function will return indicating another directory
name hook function should be tried.</p>
</li>
<li>
<p><code>p</code><br />
The name of a project within your git area.</p>
</li>
<li>
<p><code>s</code><br />
The source area within that project.</p>
</li>
</ul>
<p>This allows you to collapse references to long hierarchies to a very
compact form, particularly if the hierarchies are similar across
different areas of the disk.</p>
<p>Name components may be completed: if a description is shown at the top
of the list of completions, it includes the path to which previous
components expand, while the description for an individual completion
shows the path segment it would add. No additional configuration is
needed for this as the completion system is aware of the dynamic
directory name mechanism.</p>
<hr />
<p><span id="Usage"></span></p>
<h3 id="2641-usage"><a class="header" href="#2641-usage">26.4.1 Usage</a></h3>
<p>To use the function, first define a wrapper function for your specific
case. We’ll assume it’s to be autoloaded. This can have any name but
we’ll refer to it as zdn_mywrapper. This wrapper function will define
various variables and then call this function with the same arguments
that the wrapper function gets. This configuration is described below.</p>
<p>Then arrange for the wrapper to be run as a zsh_directory_name hook:</p>
<div class="example">
<pre><code class="language-example">autoload -Uz add-zsh-hook zsh_diretory_name_generic zdn_mywrapper
add-zsh-hook -U zsh_directory_name zdn_mywrapper
</code></pre>
</div>
<hr />
<p><span id="Configuration"></span></p>
<h3 id="2642-configuration"><a class="header" href="#2642-configuration">26.4.2 Configuration</a></h3>
<p>The wrapper function should define a local associative array zdn_top.
Alternatively, this can be set with a style called <code>mapping</code>. The
context for the style is <code>:zdn:``wrapper-name</code> where <code>wrapper-name</code> is
the function calling zsh_directory_name_generic; for example:</p>
<div class="example">
<pre><code class="language-example">zstyle :zdn:zdn_mywrapper: mapping zdn_mywrapper_top
</code></pre>
</div>
<p>The keys in this associative array correspond to the first component of
the name. The values are matching directories. They may have an optional
suffix with a slash followed by a colon and the name of a variable in
the same format to give the next component. (The slash before the colon
is to disambiguate the case where a colon is needed in the path for a
drive. There is otherwise no syntax for escaping this, so path
components whose names start with a colon are not supported.) A special
component <code>:default:</code> specifies a variable in the form <code>/:``var</code> (the
path section is ignored and so is usually empty) that will be used for
the next component if no variable is given for the path. Variables
referred to within <code>zdn_top</code> have the same format as <code>zdn_top</code> itself,
but contain relative paths.</p>
<p>For example,</p>
<div class="example">
<pre><code class="language-example">local -A zdn_top=(
g ~/git
ga ~/alternate/git
gs /scratch/$USER/git/:second2
:default: /:second1
)
</code></pre>
</div>
<p>This specifies the behaviour of a directory referred to as <code>~[g:...]</code> or
<code>~[ga:...]</code> or <code>~[gs:...]</code>. Later path components are optional; in that
case <code>~[g]</code> expands to <code>~/git</code>, and so on. <code>gs</code> expands to
<code>/scratch/$USER/git</code> and uses the associative array <code>second2</code> to match
the second component; <code>g</code> and <code>ga</code> use the associative array <code>second1</code>
to match the second component.</p>
<p>When expanding a name to a directory, if the first component is not <code>g</code>
or <code>ga</code> or <code>gs</code>, it is not an error; the function simply returns 1 so
that a later hook function can be tried. However, matching the first
component commits the function, so if a later component does not match,
an error is printed (though this still does not stop later hooks from
being executed).</p>
<p>For components after the first, a relative path is expected, but note
that multiple levels may still appear. Here is an example of <code>second1</code>:</p>
<div class="example">
<pre><code class="language-example">local -A second1=(
p myproject
s somproject
os otherproject/subproject/:third
)
</code></pre>
</div>
<p>The path as found from <code>zdn_top</code> is extended with the matching
directory, so <code>~[g:p]</code> becomes <code>~/git/myproject</code>. The slash between is
added automatically (it’s not possible to have a later component modify
the name of a directory already matched). Only <code>os</code> specifies a variable
for a third component, and there’s no <code>:default:</code>, so it’s an error to
use a name like <code>~[g:p:x]</code> or <code>~[ga:s:y]</code> because there’s nowhere to
look up the <code>x</code> or <code>y</code>.</p>
<p>The associative arrays need to be visible within this function; the
generic function therefore uses internal variable names beginning
<code>_zdn_</code> in order to avoid clashes. Note that the variable <code>reply</code> needs
to be passed back to the shell, so should not be local in the calling
function.</p>
<p>The function does not test whether directories assembled by component
actually exist; this allows the system to work across automounted file
systems. The error from the command trying to use a non-existent
directory should be sufficient to indicate the problem.</p>
<hr />
<p><span id="Complete-example"></span></p>
<h3 id="2643-complete-example"><a class="header" href="#2643-complete-example">26.4.3 Complete example</a></h3>
<p>Here is a full fictitious but usable autoloadable definition of the
example function defined by the code above. So <code>~[gs:p:s]</code> expands to
<code>/scratch/$USER/git/myscratchproject/top/srcdir</code> (with <code>$USER</code> also
expanded).</p>
<div class="example">
<pre><code class="language-example">local -A zdn_top=(
g ~/git
ga ~/alternate/git
gs /scratch/$USER/git/:second2
:default: /:second1
)
local -A second1=(
p myproject
s somproject
os otherproject/subproject/:third
)
local -A second2=(
p myscratchproject
s somescratchproject
)
local -A third=(
s top/srcdir
d top/documentation
)
# autoload not needed if you did this at initialisation...
autoload -Uz zsh_directory_name_generic
zsh_directory_name_generic &quot;$@
</code></pre>
</div>
<p>It is also possible to use global associative arrays, suitably named,
and set the style for the context of your wrapper function to refer to
this. Then your set up code would contain the following:</p>
<div class="example">
<pre><code class="language-example">typeset -A zdn_mywrapper_top=(...)
# ... and so on for other associative arrays ...
zstyle ':zdn:zdn_mywrapper:' mapping zdn_mywrapper_top
autoload -Uz add-zsh-hook zsh_directory_name_generic zdn_mywrapper
add-zsh-hook -U zsh_directory_name zdn_mywrapper
</code></pre>
</div>
<p>and the function <code>zdn_mywrapper</code> would contain only the following:</p>
<div class="example">
<pre><code class="language-example">zsh_directory_name_generic &quot;$@&quot;
</code></pre>
</div>
<hr />
<p><span id="Version-Control-Information"></span>
<span id="Gathering-information-from-version-control-systems"></span></p>
<h2 id="265-gathering-information-from-version-control-systems"><a class="header" href="#265-gathering-information-from-version-control-systems">26.5 Gathering information from version control systems</a></h2>
<p><span id="index-version-control-utility"></span></p>
<p>In a lot of cases, it is nice to automatically retrieve information from
version control systems (VCSs), such as subversion, CVS or git, to be
able to provide it to the user; possibly in the user’s prompt. So that
you can instantly tell which branch you are currently on, for example.</p>
<p>In order to do that, you may use the <code>vcs_info</code> function.</p>
<p>The following VCSs are supported, showing the abbreviated name by which
they are referred to within the system:</p>
<ul>
<li>
<p>Bazaar (<code>bzr</code>)<br />
<code>https://bazaar.canonical.com/</code></p>
</li>
<li>
<p>Codeville (<code>cdv</code>)<br />
<code>http://freecode.com/projects/codeville/</code></p>
</li>
<li>
<p>Concurrent Versioning System (<code>cvs</code>)<br />
<code>https://www.nongnu.org/cvs/</code></p>
</li>
<li>
<p>Darcs (<code>darcs</code>)<br />
<code>http://darcs.net/</code></p>
</li>
<li>
<p>Fossil (<code>fossil</code>)<br />
<code>https://fossil-scm.org/</code></p>
</li>
<li>
<p>Git (<code>git</code>)<br />
<code>https://git-scm.com/</code></p>
</li>
<li>
<p>GNU arch (<code>tla</code>)<br />
<code>https://www.gnu.org/software/gnu-arch/</code></p>
</li>
<li>
<p>Mercurial (<code>hg</code>)<br />
<code>https://www.mercurial-scm.org/</code></p>
</li>
<li>
<p>Monotone (<code>mtn</code>)<br />
<code>https://monotone.ca/</code></p>
</li>
<li>
<p>Perforce (<code>p4</code>)<br />
<code>https://www.perforce.com/</code></p>
</li>
<li>
<p>Subversion (<code>svn</code>)<br />
<code>https://subversion.apache.org/</code></p>
</li>
<li>
<p>SVK (<code>svk</code>)<br />
<code>https://svk.bestpractical.com/</code></p>
</li>
</ul>
<p>There is also support for the patch management system <code>quilt</code>
(<code>https://savannah.nongnu.org/projects/quilt</code>). See <a href="User-Contributions.html#vcs_005finfo-Quilt-Support">Quilt
Support</a> below for details.</p>
<p>To load <code>vcs_info</code>:</p>
<div class="example">
<pre><code class="language-example">autoload -Uz vcs_info
</code></pre>
</div>
<p>It can be used in any existing prompt, because it does not require any
specific <code>$psvar</code> entries to be available.</p>
<hr />
<p><span id="vcs_005finfo-Quickstart"></span> <span id="Quickstart"></span></p>
<h3 id="2651-quickstart"><a class="header" href="#2651-quickstart">26.5.1 Quickstart</a></h3>
<p>To get this feature working quickly (including colors), you can do the
following (assuming, you loaded <code>vcs_info</code> properly - see above):</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' actionformats \
'%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{3}|%F{1}%a%F{5}]%f '
zstyle ':vcs_info:*' formats \
'%F{5}(%f%s%F{5})%F{3}-%F{5}[%F{2}%b%F{5}]%f '
zstyle ':vcs_info:(sv[nk]|bzr):*' branchformat '%b%F{1}:%F{3}%r'
precmd () { vcs_info }
PS1='%F{5}[%F{2}%n%F{5}] %F{3}%3~ ${vcs_info_msg_0_}%f%# '
</code></pre>
</div>
<p>Obviously, the last two lines are there for demonstration. You need to
call <code>vcs_info</code> from your <code>precmd</code> function. Once that is done you need
a <em>single quoted</em> <code>’${vcs_info_msg_0_}’</code> in your prompt.</p>
<p>To be able to use <code>’${vcs_info_msg_0_}’</code> directly in your prompt like
this, you will need to have the <code>PROMPT_SUBST</code> option enabled.</p>
<p>Now call the <code>vcs_info_printsys</code> utility from the command line:</p>
<div class="example">
<pre><code class="language-example">% vcs_info_printsys
## list of supported version control backends:
## disabled systems are prefixed by a hash sign (#)
bzr
cdv
cvs
darcs
fossil
git
hg
mtn
p4
svk
svn
tla
## flavours (cannot be used in the enable or disable styles; they
## are enabled and disabled with their master [git-svn -&gt; git])
## they *can* be used in contexts: ':vcs_info:git-svn:*'.
git-p4
git-svn
hg-git
hg-hgsubversion
hg-hgsvn
</code></pre>
</div>
<p>You may not want all of these because there is no point in running the
code to detect systems you do not use. So there is a way to disable some
backends altogether:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' disable bzr cdv darcs mtn svk tla
</code></pre>
</div>
<p>You may also pick a few from that list and enable only those:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' enable git cvs svn
</code></pre>
</div>
<p>If you rerun <code>vcs_info_printsys</code> after one of these commands, you will
see the backends listed in the <code>disable</code> style (or backends not in the
<code>enable</code> style - if you used that) marked as disabled by a hash sign.
That means the detection of these systems is skipped <em>completely</em>. No
wasted time there.</p>
<hr />
<p><span id="vcs_005finfo-Configuration"></span>
<span id="Configuration-1"></span></p>
<h3 id="2652-configuration"><a class="header" href="#2652-configuration">26.5.2 Configuration</a></h3>
<p>The <code>vcs_info</code> feature can be configured via <code>zstyle</code>.</p>
<p>First, the context in which we are working:</p>
<div class="example">
<pre><code class="language-example">:vcs_info:vcs-string:user-context:repo-root-name
</code></pre>
</div>
<ul>
<li>
<p><code>vcs-string</code><br />
is one of: <code>git</code>, <code>git-svn</code>, <code>git-p4</code>, <code>hg</code>, <code>hg-git</code>,
<code>hg-hgsubversion</code>, <code>hg-hgsvn</code>, <code>darcs</code>, <code>bzr</code>, <code>cdv</code>, <code>mtn</code>, <code>svn</code>,
<code>cvs</code>, <code>svk</code>, <code>tla</code>, <code>p4</code> or <code>fossil</code>. This is followed by
‘<code>.quilt-``quilt-mode</code>’ in Quilt mode (see <a href="User-Contributions.html#vcs_005finfo-Quilt-Support">Quilt
Support</a> for details) and by
‘<code>+``hook-name</code>’ while hooks are active (see <a href="User-Contributions.html#vcs_005finfo-Hooks">Hooks in
vcs_info</a> for details).</p>
<p>Currently, hooks in quilt mode don’t add the ‘<code>.quilt-``quilt-mode</code>’
information. This may change in the future.</p>
</li>
<li>
<p><code>user-context</code><br />
is a freely configurable string, assignable by the user as the first
argument to <code>vcs_info</code> (see its description below).</p>
</li>
<li>
<p><code>repo-root-name</code><br />
is the name of a repository in which you want a style to match. So,
if you want a setting specific to <code>/usr/src/zsh</code>, with that being a
CVS checkout, you can set <code>repo-root-name</code> to <code>zsh</code> to make it so.</p>
</li>
</ul>
<p>There are three special values for <code>vcs-string</code>: The first is named
<code>-init-</code>, that is in effect as long as there was no decision what VCS
backend to use. The second is <code>-preinit-</code>; it is used <em>before</em>
<code>vcs_info</code> is run, when initializing the data exporting variables. The
third special value is <code>formats</code> and is used by the <code>vcs_info_lastmsg</code>
for looking up its styles.</p>
<p>The initial value of <code>repo-root-name</code> is <code>-all-</code> and it is replaced with
the actual name, as soon as it is known. Only use this part of the
context for defining the <code>formats</code>, <code>actionformats</code> or <code>branchformat</code>
styles, as it is guaranteed that <code>repo-root-name</code> is set up correctly
for these only. For all other styles, just use <code>’*’</code> instead.</p>
<p>There are two pre-defined values for <code>user-context</code>:</p>
<ul>
<li>
<p><code>default</code><br />
the one used if none is specified</p>
</li>
<li>
<p><code>command</code><br />
used by vcs_info_lastmsg to lookup its styles</p>
</li>
</ul>
<p>You can of course use <code>’:vcs_info:*’</code> to match all VCSs in all
user-contexts at once.</p>
<p>This is a description of all styles that are looked up.</p>
<p><span id="index-formats"></span></p>
<p><code>formats</code></p>
<p>A list of formats, used when actionformats is not used (which is most of
the time).</p>
<p><span id="index-actionformats"></span></p>
<p><code>actionformats</code></p>
<p>A list of formats, used if there is a special action going on in your
current repository; like an interactive rebase or a merge conflict.</p>
<p><span id="index-branchformat"></span></p>
<p><code>branchformat</code></p>
<p>Some backends replace <code>%b</code> in the formats and actionformats styles
above, not only by a branch name but also by a revision number. This
style lets you modify how that string should look.</p>
<p><span id="index-nvcsformats"></span></p>
<p><code>nvcsformats</code></p>
<p>These &quot;formats&quot; are set when we didn’t detect a version control system
for the current directory or <code>vcs_info</code> was disabled. This is useful if
you want <code>vcs_info</code> to completely take over the generation of your
prompt. You would do something like <code>PS1=’${vcs_info_msg_0_}’</code> to
accomplish that.</p>
<p><span id="index-hgrevformat"></span></p>
<p><code>hgrevformat</code></p>
<p><code>hg</code> uses both a hash and a revision number to reference a specific
changeset in a repository. With this style you can format the revision
string (see <code>branchformat</code>) to include either or both. It’s only useful
when <code>get-revision</code> is true. Note, the full 40-character revision id is
not available (except when using the <code>use-simple</code> option) because
executing hg more than once per prompt is too slow; you may customize
this behavior using hooks.</p>
<p><span id="index-max_002dexports"></span></p>
<p><code>max-exports</code></p>
<p>Defines the maximum number of <code>vcs_info_msg_*_</code> variables <code>vcs_info</code>
will set.</p>
<p><span id="index-enable-1"></span></p>
<p><code>enable</code></p>
<p>A list of backends you want to use. Checked in the <code>-init-</code> context. If
this list contains an item called <code>NONE</code> no backend is used at all and
<code>vcs_info</code> will do nothing. If this list contains <code>ALL</code>, <code>vcs_info</code> will
use all known backends. Only with <code>ALL</code> in <code>enable</code> will the <code>disable</code>
style have any effect. <code>ALL</code> and <code>NONE</code> are case insensitive.</p>
<p><span id="index-disable-1"></span></p>
<p><code>disable</code></p>
<p>A list of VCSs you don’t want <code>vcs_info</code> to test for repositories
(checked in the <code>-init-</code> context, too). Only used if <code>enable</code> contains
<code>ALL</code>.</p>
<p><span id="index-disable_002dpatterns"></span></p>
<p><code>disable-patterns</code></p>
<p>A list of patterns that are checked against <code>$PWD</code>. If a pattern
matches, <code>vcs_info</code> will be disabled. This style is checked in the
<code>:vcs_info:-init-:*:-all-</code> context.</p>
<p>Say, <code>~/.zsh</code> is a directory under version control, in which you do not
want <code>vcs_info</code> to be active, do:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' disable-patterns &quot;${(b)HOME}/.zsh(|/*)&quot;
</code></pre>
</div>
<p><span id="index-use_002dquilt"></span></p>
<p><code>use-quilt</code></p>
<p>If enabled, the <code>quilt</code> support code is active in ‘addon’ mode. See
<a href="User-Contributions.html#vcs_005finfo-Quilt-Support">Quilt Support</a> for details.</p>
<p><span id="index-quilt_002dstandalone"></span></p>
<p><code>quilt-standalone</code></p>
<p>If enabled, ‘standalone’ mode detection is attempted if no VCS is active
in a given directory. See <a href="User-Contributions.html#vcs_005finfo-Quilt-Support">Quilt Support</a>
for details.</p>
<p><span id="index-quilt_002dpatch_002ddir"></span></p>
<p><code>quilt-patch-dir</code></p>
<p>Overwrite the value of the <code>$QUILT_PATCHES</code> environment variable. See
<a href="User-Contributions.html#vcs_005finfo-Quilt-Support">Quilt Support</a> for details.</p>
<p><span id="index-quiltcommand"></span></p>
<p><code>quiltcommand</code></p>
<p>When <code>quilt</code> itself is called in quilt support, the value of this style
is used as the command name.</p>
<p><span id="index-check_002dfor_002dchanges"></span></p>
<p><code>check-for-changes</code></p>
<p>If enabled, this style causes the <code>%c</code> and <code>%u</code> format escapes to show
when the working directory has uncommitted changes. The strings
displayed by these escapes can be controlled via the <code>stagedstr</code> and
<code>unstagedstr</code> styles. The only backends that currently support this
option are <code>git</code>, <code>hg</code>, and <code>bzr</code> (the latter two only support
unstaged).</p>
<p>For this style to be evaluated with the <code>hg</code> backend, the <code>get-revision</code>
style needs to be set and the <code>use-simple</code> style needs to be unset. The
latter is the default; the former is not.</p>
<p>With the <code>bzr</code> backend, <em>lightweight checkouts</em> only honor this style if
the <code>use-server</code> style is set.</p>
<p>Note, the actions taken if this style is enabled are potentially
expensive (read: they may be slow, depending on how big the current
repository is). Therefore, it is disabled by default.</p>
<p><span id="index-check_002dfor_002dstaged_002dchanges"></span></p>
<p><code>check-for-staged-changes</code></p>
<p>This style is like <code>check-for-changes</code>, but it never checks the worktree
files, only the metadata in the <code>.${vcs}</code> dir. Therefore, this style
initializes only the <code>%c</code> escape (with <code>stagedstr</code>) but not the <code>%u</code>
escape. This style is faster than <code>check-for-changes</code>.</p>
<p>In the <code>git</code> backend, this style checks for changes in the index. Other
backends do not currently implement this style.</p>
<p>This style is disabled by default.</p>
<p><span id="index-stagedstr"></span></p>
<p><code>stagedstr</code></p>
<p>This string will be used in the <code>%c</code> escape if there are staged changes
in the repository.</p>
<p><span id="index-unstagedstr"></span></p>
<p><code>unstagedstr</code></p>
<p>This string will be used in the <code>%u</code> escape if there are unstaged
changes in the repository.</p>
<p><span id="index-command-2"></span></p>
<p><code>command</code></p>
<p>This style causes <code>vcs_info</code> to use the supplied string as the command
to use as the VCS’s binary. Note, that setting this in ’<code>:vcs_info:*</code>’
is not a good idea.</p>
<p>If the value of this style is empty (which is the default), the used
binary name is the name of the backend in use (e.g. <code>svn</code> is used in an
<code>svn</code> repository).</p>
<p>The <code>repo-root-name</code> part in the context is always the default <code>-all-</code>
when this style is looked up.</p>
<p>For example, this style can be used to use binaries from non-default
installation directories. Assume, <code>git</code> is installed in /usr/bin but
your sysadmin installed a newer version in /usr/local/bin. Instead of
changing the order of your <code>$PATH</code> parameter, you can do this:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:git:*:-all-' command /usr/local/bin/git
</code></pre>
</div>
<p><span id="index-use_002dserver"></span></p>
<p><code>use-server</code></p>
<p>This is used by the Perforce backend (<code>p4</code>) to decide if it should
contact the Perforce server to find out if a directory is managed by
Perforce. This is the only reliable way of doing this, but runs the risk
of a delay if the server name cannot be found. If the server (more
specifically, the <code>host``:``port</code> pair describing the server) cannot be
contacted, its name is put into the associative array
<code>vcs_info_p4_dead_servers</code> and is not contacted again during the session
until it is removed by hand. If you do not set this style, the <code>p4</code>
backend is only usable if you have set the environment variable
<code>P4CONFIG</code> to a file name and have corresponding files in the root
directories of each Perforce client. See comments in the function
<code>VCS_INFO_detect_p4</code> for more detail.</p>
<p>The Bazaar backend (<code>bzr</code>) uses this to permit contacting the server
about lightweight checkouts, see the <code>check-for-changes</code> style.</p>
<p><span id="index-use_002dsimple"></span></p>
<p><code>use-simple</code></p>
<p>If there are two different ways of gathering information, you can select
the simpler one by setting this style to true; the default is to use the
not-that-simple code, which is potentially a lot slower but might be
more accurate in all possible cases. This style is used by the <code>bzr</code> and
<code>hg</code> backends. In the case of <code>hg</code> it will invoke the external hexdump
program to parse the binary dirstate cache file; this method will not
return the local revision number.</p>
<p><span id="index-get_002drevision"></span></p>
<p><code>get-revision</code></p>
<p>If set to true, vcs_info goes the extra mile to figure out the revision
of a repository’s work tree (currently for the <code>git</code> and <code>hg</code> backends,
where this kind of information is not always vital). For <code>git</code>, the hash
value of the currently checked out commit is available via the <code>%i</code>
expansion. With <code>hg</code>, the local revision number and the corresponding
global hash are available via <code>%i</code>.</p>
<p><span id="index-get_002dmq"></span></p>
<p><code>get-mq</code></p>
<p>If set to true, the <code>hg</code> backend will look for a Mercurial Queue (<code>mq</code>)
patch directory. Information will be available via the ‘<code>%m</code>’
replacement.</p>
<p><span id="index-get_002dbookmarks"></span></p>
<p><code>get-bookmarks</code></p>
<p>If set to true, the <code>hg</code> backend will try to get a list of current
bookmarks. They will be available via the ‘<code>%m</code>’ replacement.</p>
<p>The default is to generate a comma-separated list of all bookmark names
that refer to the currently checked out revision. If a bookmark is
active, its name is suffixed an asterisk and placed first in the list.</p>
<p><span id="index-use_002dprompt_002descapes"></span></p>
<p><code>use-prompt-escapes</code></p>
<p>Determines if we assume that the assembled string from <code>vcs_info</code>
includes prompt escapes. (Used by <code>vcs_info_lastmsg</code>.)</p>
<p><span id="index-debug"></span></p>
<p><code>debug</code></p>
<p>Enable debugging output to track possible problems. Currently this style
is only used by <code>vcs_info</code>’s hooks system.</p>
<p><span id="index-hooks"></span></p>
<p><code>hooks</code></p>
<p>A list style that defines hook-function names. See <a href="User-Contributions.html#vcs_005finfo-Hooks">Hooks in
vcs_info</a> below for details.</p>
<p><span id="index-patch_002dformat"></span>
<span id="index-nopatch_002dformat"></span></p>
<p><code>patch-format</code></p>
<p><code>nopatch-format</code></p>
<p>This pair of styles format the patch information used by the <code>%m</code>
expando in formats and actionformats for the <code>git</code> and <code>hg</code> backends.
The value is subject to certain <code>%</code>-expansions described below. The
expanded value is made available in the global <code>backend_misc</code> array as
<code>${backend_misc[patches]}</code> (also if a <code>set-patch-format</code> hook is used).</p>
<p><span id="index-get_002dunapplied"></span></p>
<p><code>get-unapplied</code></p>
<p>This boolean style controls whether a backend should attempt to gather a
list of unapplied patches (for example with Mercurial Queue patches).</p>
<p>Used by the <code>quilt</code> and <code>hg</code> backends.</p>
<p>The default values for these styles in all contexts are:</p>
<ul>
<li>
<p><code>formats</code><br />
&quot; (%s)-[%b]%u%c-&quot;</p>
</li>
<li>
<p><code>actionformats</code><br />
&quot; (%s)-[%b|%a]%u%c-&quot;</p>
</li>
<li>
<p><code>branchformat</code><br />
&quot;%b:%r&quot; (for bzr, svn, svk and hg)</p>
</li>
<li>
<p><code>nvcsformats</code><br />
&quot;&quot;</p>
</li>
<li>
<p><code>hgrevformat</code><br />
&quot;%r:%h&quot;</p>
</li>
<li>
<p><code>max-exports</code><br />
2</p>
</li>
<li>
<p><code>enable</code><br />
ALL</p>
</li>
<li>
<p><code>disable</code><br />
(empty list)</p>
</li>
<li>
<p><code>disable-patterns</code><br />
(empty list)</p>
</li>
<li>
<p><code>check-for-changes</code><br />
false</p>
</li>
<li>
<p><code>check-for-staged-changes</code><br />
false</p>
</li>
<li>
<p><code>stagedstr</code><br />
(string: &quot;S&quot;)</p>
</li>
<li>
<p><code>unstagedstr</code><br />
(string: &quot;U&quot;)</p>
</li>
<li>
<p><code>command</code><br />
(empty string)</p>
</li>
<li>
<p><code>use-server</code><br />
false</p>
</li>
<li>
<p><code>use-simple</code><br />
false</p>
</li>
<li>
<p><code>get-revision</code><br />
false</p>
</li>
<li>
<p><code>get-mq</code><br />
true</p>
</li>
<li>
<p><code>get-bookmarks</code><br />
false</p>
</li>
<li>
<p><code>use-prompt-escapes</code><br />
true</p>
</li>
<li>
<p><code>debug</code><br />
false</p>
</li>
<li>
<p><code>hooks</code><br />
(empty list)</p>
</li>
<li>
<p><code>use-quilt</code><br />
false</p>
</li>
<li>
<p><code>quilt-standalone</code><br />
false</p>
</li>
<li>
<p><code>quilt-patch-dir</code><br />
empty - use <code>$QUILT_PATCHES</code></p>
</li>
<li>
<p><code>quiltcommand</code><br />
quilt</p>
</li>
<li>
<p><code>patch-format</code><br />
<code>backend dependent</code></p>
</li>
<li>
<p><code>nopatch-format</code><br />
<code>backend dependent</code></p>
</li>
<li>
<p><code>get-unapplied</code><br />
false</p>
</li>
</ul>
<p>In normal <code>formats</code> and <code>actionformats</code> the following replacements are
done:</p>
<ul>
<li>
<p><code>%s</code><br />
The VCS in use (git, hg, svn, etc.).</p>
</li>
<li>
<p><code>%b</code><br />
Information about the current branch.</p>
</li>
<li>
<p><code>%a</code><br />
An identifier that describes the action. Only makes sense in
<code>actionformats</code>.</p>
</li>
<li>
<p><code>%i</code><br />
The current revision number or identifier. For <code>hg</code> the
<code>hgrevformat</code> style may be used to customize the output.</p>
</li>
<li>
<p><code>%c</code><br />
The string from the <code>stagedstr</code> style if there are staged changes in
the repository.</p>
</li>
<li>
<p><code>%u</code><br />
The string from the <code>unstagedstr</code> style if there are unstaged
changes in the repository.</p>
</li>
<li>
<p><code>%R</code><br />
The base directory of the repository.</p>
</li>
<li>
<p><code>%r</code><br />
The repository name. If <code>%R</code> is <code>/foo/bar/repoXY</code>, <code>%r</code> is <code>repoXY</code>.</p>
</li>
<li>
<p><code>%S</code><br />
A subdirectory within a repository. If <code>$PWD</code> is
<code>/foo/bar/repoXY/beer/tasty</code>, <code>%S</code> is <code>beer/tasty</code>.</p>
</li>
</ul>
<!-- end list -->
<ul>
<li>
<p><code>%m</code><br />
A &quot;misc&quot; replacement. It is at the discretion of the backend to
decide what this replacement expands to.</p>
<p>The <code>hg</code> and <code>git</code> backends use this expando to display patch
information. <code>hg</code> sources patch information from the <code>mq</code>
extensions; <code>git</code> from in-progress <code>rebase</code> and <code>cherry-pick</code>
operations and from the <code>stgit</code> extension. The <code>patch-format</code> and
<code>nopatch-format</code> styles control the generated string. The former is
used when at least one patch from the patch queue has been applied,
and the latter otherwise.</p>
<p>The <code>hg</code> backend displays bookmark information in this expando (in
addition to <code>mq</code> information). See the <code>get-mq</code> and <code>get-bookmarks</code>
styles. Both of these styles may be enabled at the same time. If
both are enabled, both resulting strings will be shown separated by
a semicolon (that cannot currently be customized).</p>
<p>The <code>quilt</code> ‘standalone’ backend sets this expando to the same value
as the <code>%Q</code> expando.</p>
</li>
<li>
<p><code>%Q</code><br />
Quilt series information. When quilt is used (either in ‘addon’ mode
or as a ‘standalone’ backend), this expando is set to quilt series’
<code>patch-format</code> string. The <code>set-patch-format</code> hook and
<code>nopatch-format</code> style are honoured.</p>
<p>See <a href="User-Contributions.html#vcs_005finfo-Quilt-Support">Quilt Support</a> below for details.</p>
</li>
</ul>
<p>In <code>branchformat</code> these replacements are done:</p>
<ul>
<li>
<p><code>%b</code><br />
The branch name.</p>
</li>
<li>
<p><code>%r</code><br />
The current revision number or the <code>hgrevformat</code> style for <code>hg</code>.</p>
</li>
</ul>
<p>In <code>hgrevformat</code> these replacements are done:</p>
<ul>
<li>
<p><code>%r</code><br />
The current local revision number.</p>
</li>
<li>
<p><code>%h</code><br />
The current global revision identifier.</p>
</li>
</ul>
<p>In <code>patch-format</code> and <code>nopatch-format</code> these replacements are done:</p>
<ul>
<li>
<p><code>%p</code><br />
The name of the top-most applied patch; may be overridden by the
<code>applied-string</code> hook.</p>
</li>
<li>
<p><code>%u</code><br />
The number of unapplied patches; may be overridden by the
<code>unapplied-string</code> hook.</p>
</li>
<li>
<p><code>%n</code><br />
The number of applied patches.</p>
</li>
<li>
<p><code>%c</code><br />
The number of unapplied patches.</p>
</li>
<li>
<p><code>%a</code><br />
The number of all patches (<code>%a = %n + %c</code>).</p>
</li>
<li>
<p><code>%g</code><br />
The names of active <code>mq</code> guards (<code>hg</code> backend).</p>
</li>
<li>
<p><code>%G</code><br />
The number of active <code>mq</code> guards (<code>hg</code> backend).</p>
</li>
</ul>
<p>Not all VCS backends have to support all replacements. For <code>nvcsformats</code>
no replacements are performed at all, it is just a string.</p>
<hr />
<p><span id="vcs_005finfo-Oddities"></span> <span id="Oddities"></span></p>
<h3 id="2653-oddities"><a class="header" href="#2653-oddities">26.5.3 Oddities</a></h3>
<p>If you want to use the <code>%b</code> (bold off) prompt expansion in <code>formats</code>,
which expands <code>%b</code> itself, use <code>%%b</code>. That will cause the <code>vcs_info</code>
expansion to replace <code>%%b</code> with <code>%b</code>, so that zsh’s prompt expansion
mechanism can handle it. Similarly, to hand down <code>%b</code> from
<code>branchformat</code>, use <code>%%%%b</code>. Sorry for this inconvenience, but it cannot
be easily avoided. Luckily we do not clash with a lot of prompt
expansions and this only needs to be done for those.</p>
<p>When one of the <code>gen-applied-string</code>, <code>gen-unapplied-string</code>, and
<code>set-patch-format</code> hooks is defined, applying <code>%</code>-escaping
(‘<code>foo=${foo//’%’/%%}</code>’) to the interpolated values for use in the
prompt is the responsibility of those hooks (jointly); when neither of
those hooks is defined, <code>vcs_info</code> handles escaping by itself. We regret
this coupling, but it was required for backwards compatibility.</p>
<hr />
<p><span id="vcs_005finfo-Quilt-Support"></span>
<span id="Quilt-Support"></span></p>
<h3 id="2654-quilt-support"><a class="header" href="#2654-quilt-support">26.5.4 Quilt Support</a></h3>
<p>Quilt is not a version control system, therefore this is not implemented
as a backend. It can help keeping track of a series of patches. People
use it to keep a set of changes they want to use on top of software
packages (which is tightly integrated into the package build process -
the Debian project does this for a large number of packages). Quilt can
also help individual developers keep track of their own patches on top
of real version control systems.</p>
<p>The <code>vcs_info</code> integration tries to support both ways of using quilt by
having two slightly different modes of operation: ‘addon’ mode and
‘standalone’ mode).</p>
<p>Quilt integration is off by default; to enable it, set the <code>use-quilt</code>
style, and add <code>%Q</code> to your <code>formats</code> or <code>actionformats</code> style:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' use-quilt true
</code></pre>
</div>
<p>Styles looked up from the Quilt support code include
‘<code>.quilt-``quilt-mode</code>’ in the <code>vcs-string</code> part of the context, where
<code>quilt-mode</code> is either <code>addon</code> or <code>standalone</code>. Example:
<code>:vcs_info:git.quilt-addon:default:``repo-root-name</code>.</p>
<p>For ‘addon’ mode to become active <code>vcs_info</code> must have already detected
a real version control system controlling the directory. If that is the
case, a directory that holds quilt’s patches needs to be found. That
directory is configurable via the ‘<code>QUILT_PATCHES</code>’ environment
variable. If that variable exists its value is used, otherwise the value
‘<code>patches</code>’ is assumed. The value from <code>$QUILT_PATCHES</code> can be
overwritten using the ‘<code>quilt-patches</code>’ style. (Note: you can use
<code>vcs_info</code> to keep the value of <code>$QUILT_PATCHES</code> correct all the time
via the <code>post-quilt</code> hook).</p>
<p>When the directory in question is found, quilt is assumed to be active.
To gather more information, <code>vcs_info</code> looks for a directory called
‘.pc’; Quilt uses that directory to track its current state. If this
directory does not exist we know that quilt has not done anything to the
working directory (read: no patches have been applied yet).</p>
<p>If patches are applied, <code>vcs_info</code> will try to find out which. If you
want to know which patches of a series are not yet applied, you need to
activate the <code>get-unapplied</code> style in the appropriate context.</p>
<p><code>vcs_info</code> allows for very detailed control over how the gathered
information is presented (see
<a href="User-Contributions.html#vcs_005finfo-Configuration">Configuration</a> and <a href="User-Contributions.html#vcs_005finfo-Hooks">Hooks in
vcs_info</a>), all of which are documented below.
Note there are a number of other patch tracking systems that work on top
of a certain version control system (like <code>stgit</code> for git, or <code>mq</code> for
hg); the configuration for systems like that are generally configured
the same way as the quilt support.</p>
<p>If the quilt support is working in ‘addon’ mode, the produced string is
available as a simple format replacement (<code>%Q</code> to be precise), which can
be used in <code>formats</code> and <code>actionformats</code>; see below for details).</p>
<p>If, on the other hand, the support code is working in ‘standalone’ mode,
<code>vcs_info</code> will pretend as if <code>quilt</code> were an actual version control
system. That means that the version control system identifier (which
otherwise would be something like ‘svn’ or ‘cvs’) will be set to
‘<code>-quilt-</code>’. This has implications on the used style context where
this identifier is the second element. <code>vcs_info</code> will have filled in a
proper value for the &quot;repository’s&quot; root directory and the string
containing the information about quilt’s state will be available as the
‘misc’ replacement (and <code>%Q</code> for compatibility with ‘addon’ mode).</p>
<p>What is left to discuss is how ‘standalone’ mode is detected. The
detection itself is a series of searches for directories. You can have
this detection enabled all the time in every directory that is not
otherwise under version control. If you know there is only a limited set
of trees where you would like <code>vcs_info</code> to try and look for Quilt in
‘standalone’ mode to minimise the amount of searching on every call to
<code>vcs_info</code>, there are a number of ways to do that:</p>
<p>Essentially, ‘standalone’ mode detection is controlled by a style called
‘<code>quilt-standalone</code>’. It is a string style and its value can have
different effects. The simplest values are: ‘<code>always</code>’ to run detection
every time <code>vcs_info</code> is run, and ‘<code>never</code>’ to turn the detection off
entirely.</p>
<p>If the value of <code>quilt-standalone</code> is something else, it is interpreted
differently. If the value is the name of a scalar variable the value of
that variable is checked and that value is used in the same
‘always’/‘never’ way as described above.</p>
<p>If the value of <code>quilt-standalone</code> is an array, the elements of that
array are used as directory names under which you want the detection to
be active.</p>
<p>If <code>quilt-standalone</code> is an associative array, the keys are taken as
directory names under which you want the detection to be active, but
only if the corresponding value is the string ‘<code>true</code>’.</p>
<p>Last, but not least, if the value of <code>quilt-standalone</code> is the name of a
function, the function is called without arguments and the return value
decides whether detection should be active. A ‘0’ return value is true;
a non-zero return value is interpreted as false.</p>
<p>Note, if there is both a function and a variable by the name of
<code>quilt-standalone</code>, the function will take precedence.</p>
<hr />
<p><span id="vcs_005finfo-API"></span>
<span id="Function-Descriptions-_0028Public-API_0029"></span></p>
<h3 id="2655-function-descriptions-public-api"><a class="header" href="#2655-function-descriptions-public-api">26.5.5 Function Descriptions (Public API)</a></h3>
<p><span id="index-vcs_005finfo"></span></p>
<p><code>vcs_info</code> [<code>user-context</code>]</p>
<p>The main function, that runs all backends and assembles all data into
<code>${vcs_info_msg_*_}</code>. This is the function you want to call from
<code>precmd</code> if you want to include up-to-date information in your prompt
(see <a href="User-Contributions.html#vcs_005finfo-Variables">Variable Description</a> below). If an
argument is given, that string will be used instead of <code>default</code> in the
<code>user-context</code> field of the style context.</p>
<p><span id="index-vcs_005finfo_005fhookadd"></span></p>
<p><code>vcs_info_hookadd</code></p>
<p>Statically registers a number of functions to a given hook. The hook
needs to be given as the first argument; what follows is a list of
hook-function names to register to the hook. The ‘<code>+vi-</code>’ prefix needs
to be left out here. See <a href="User-Contributions.html#vcs_005finfo-Hooks">Hooks in vcs_info</a> below
for details.</p>
<p><span id="index-vcs_005finfo_005fhookdel"></span></p>
<p><code>vcs_info_hookdel</code></p>
<p>Remove hook-functions from a given hook. The hook needs to be given as
the first non-option argument; what follows is a list of hook-function
names to un-register from the hook. If ‘<code>-a</code>’ is used as the first
argument, <code>all</code> occurrences of the functions are unregistered. Otherwise
only the last occurrence is removed (if a function was registered to a
hook more than once). The ‘<code>+vi-</code>’ prefix needs to be left out here. See
<a href="User-Contributions.html#vcs_005finfo-Hooks">Hooks in vcs_info</a> below for details.</p>
<p><span id="index-vcs_005finfo_005flastmsg"></span></p>
<p><code>vcs_info_lastmsg</code></p>
<p>Outputs the last <code>${vcs_info_msg_*_}</code> value. Takes into account the
value of the <code>use-prompt-escapes</code> style in
<code>’:vcs_info:formats:command:-all-’</code>. It also only prints <code>max-exports</code>
values.</p>
<p><span id="index-vcs_005finfo_005fprintsys"></span></p>
<p><code>vcs_info_printsys</code> [<code>user-context</code>]</p>
<p>Prints a list of all supported version control systems. Useful to find
out possible contexts (and which of them are enabled) or values for the
<code>disable</code> style.</p>
<p><span id="index-vcs_005finfo_005fsetsys"></span></p>
<p><code>vcs_info_setsys</code></p>
<p>Initializes <code>vcs_info</code>’s internal list of available backends. With this
function, you can add support for new VCSs without restarting the shell.</p>
<p>All functions named <code>VCS_INFO_*</code> are for internal use only.</p>
<hr />
<p><span id="vcs_005finfo-Variables"></span>
<span id="Variable-Description"></span></p>
<h3 id="2656-variable-description"><a class="header" href="#2656-variable-description">26.5.6 Variable Description</a></h3>
<ul>
<li><code>${vcs_info_msg_``N``_}</code> (Note the trailing underscore)<br />
Where <code>N</code> is an integer, e.g., <code>vcs_info_msg_0_</code>. These variables
are the storage for the informational message the last <code>vcs_info</code>
call has assembled. These are strongly connected to the <code>formats</code>,
<code>actionformats</code> and <code>nvcsformats</code> styles described above. Those
styles are lists. The first member of that list gets expanded into
<code>${vcs_info_msg_0_}</code>, the second into <code>${vcs_info_msg_1_}</code> and the
Nth into <code>${vcs_info_msg_N-1_}</code>. (See the <code>max-exports</code> style
above.)</li>
</ul>
<p>All variables named <code>VCS_INFO_*</code> are for internal use only.</p>
<hr />
<p><span id="vcs_005finfo-Hooks"></span>
<span id="Hooks-in-vcs_005finfo"></span></p>
<h3 id="2657-hooks-in-vcs_info"><a class="header" href="#2657-hooks-in-vcs_info">26.5.7 Hooks in vcs_info</a></h3>
<p>Hooks are places in <code>vcs_info</code> where you can run your own code. That
code can communicate with the code that called it and through that,
change the system’s behaviour.</p>
<p>For configuration, hooks change the style context:</p>
<div class="example">
<pre><code class="language-example">:vcs_info:vcs-string+hook-name:user-context:repo-root-name
</code></pre>
</div>
<p>To register functions to a hook, you need to list them in the <code>hooks</code>
style in the appropriate context.</p>
<p>Example:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*+foo:*' hooks bar baz
</code></pre>
</div>
<p>This registers functions to the hook ‘foo’ for all backends. In order to
avoid namespace problems, all registered function names are prepended by
a ‘<code>+vi-</code>’, so the actual functions called for the ‘foo’ hook are
‘<code>+vi-bar</code>’ and ‘<code>+vi-baz</code>’.</p>
<p>If you would like to register a function to a hook regardless of the
current context, you may use the <code>vcs_info_hookadd</code> function. To remove
a function that was added like that, the <code>vcs_info_hookdel</code> function can
be used.</p>
<p>If something seems weird, you can enable the ‘debug’ boolean style in
the proper context and the hook-calling code will print what it tried to
execute and whether the function in question existed.</p>
<p>When you register more than one function to a hook, all functions are
executed one after another until one function returns non-zero or until
all functions have been called. Context-sensitive hook functions are
executed <code>before</code> statically registered ones (the ones added by
<code>vcs_info_hookadd</code>).</p>
<p>You may pass data between functions via an associative array,
<code>user_data</code>. For example:</p>
<div class="example">
<pre><code class="language-example">+vi-git-myfirsthook(){
user_data[myval]=$myval
}
+vi-git-mysecondhook(){
# do something with ${user_data[myval]}
}
</code></pre>
</div>
<p>There are a number of variables that are special in hook contexts:</p>
<ul>
<li>
<p><code>ret</code><br />
The return value that the hooks system will return to the caller.
The default is an integer ‘zero’. If and how a changed <code>ret</code> value
changes the execution of the caller depends on the specific hook.
See the hook documentation below for details.</p>
</li>
<li>
<p><code>hook_com</code><br />
An associated array which is used for bidirectional communication
from the caller to hook functions. The used keys depend on the
specific hook.</p>
</li>
<li>
<p><code>context</code><br />
The active context of the hook. Functions that wish to change this
variable should make it local scope first.</p>
</li>
<li>
<p><code>vcs</code><br />
The current VCS after it was detected. The same values as in the
enable/disable style are used. Available in all hooks except
<code>start-up</code>.</p>
</li>
</ul>
<p>Finally, the full list of currently available hooks:</p>
<ul>
<li>
<p><code>start-up</code><br />
Called after starting <code>vcs_info</code> but before the VCS in this
directory is determined. It can be used to deactivate <code>vcs_info</code>
temporarily if necessary. When <code>ret</code> is set to <code>1</code>, <code>vcs_info</code>
aborts and does nothing; when set to <code>2</code>, <code>vcs_info</code> sets up
everything as if no version control were active and exits.</p>
</li>
<li>
<p><code>pre-get-data</code><br />
Same as <code>start-up</code> but after the VCS was detected.</p>
</li>
<li>
<p><code>gen-hg-bookmark-string</code><br />
Called in the Mercurial backend when a bookmark string is generated;
the <code>get-revision</code> and <code>get-bookmarks</code> styles must be true.</p>
<p>This hook gets the names of the Mercurial bookmarks that <code>vcs_info</code>
collected from ‘hg’.</p>
<p>If a bookmark is active, the key <code>${hook_com[hg-active-bookmark]}</code>
is set to its name. The key is otherwise unset.</p>
<p>When setting <code>ret</code> to non-zero, the string in
<code>${hook_com[hg-bookmark-string]}</code> will be used in the <code>%m</code> escape in
<code>formats</code> and <code>actionformats</code> and will be available in the global
<code>backend_misc</code> array as <code>${backend_misc[bookmarks]}</code>.</p>
</li>
<li>
<p><code>gen-applied-string</code><br />
Called in the <code>git</code> (with <code>stgit</code> or during rebase or merge), and
<code>hg</code> (with <code>mq</code>) backends and in <code>quilt</code> support when the
<code>applied-string</code> is generated; the <code>use-quilt</code> zstyle must be true
for <code>quilt</code> (the <code>mq</code> and <code>stgit</code> backends are active by default).</p>
<p>This hook gets the names of all applied patches which <code>vcs_info</code>
collected so far in the opposite order, which means that the first
argument is the top-most patch and so forth.</p>
<p>When setting <code>ret</code> to non-zero, the string in
<code>${hook_com[applied-string]}</code> will be available as <code>%p</code> in the
<code>patch-format</code> and <code>nopatch-format</code> styles. This hook is, in concert
with <code>set-patch-format</code>, responsible for <code>%</code>-escaping that value for
use in the prompt. (See <a href="User-Contributions.html#vcs_005finfo-Oddities">Oddities</a>.)</p>
</li>
<li>
<p><code>gen-unapplied-string</code><br />
Called in the <code>git</code> (with <code>stgit</code> or during rebase), and <code>hg</code> (with
<code>mq</code>) backend and in <code>quilt</code> support when the <code>unapplied-string</code> is
generated; the <code>get-unapplied</code> style must be true.</p>
<p>This hook gets the names of all unapplied patches which <code>vcs_info</code>
collected so far in order, which means that the first argument is
the patch next-in-line to be applied and so forth.</p>
<p>When setting <code>ret</code> to non-zero, the string in
<code>${hook_com[unapplied-string]}</code> will be available as <code>%u</code> in the
<code>patch-format</code> and <code>nopatch-format</code> styles. This hook is, in concert
with <code>set-patch-format</code>, responsible for <code>%</code>-escaping that value for
use in the prompt. (See <a href="User-Contributions.html#vcs_005finfo-Oddities">Oddities</a>.)</p>
</li>
<li>
<p><code>gen-mqguards-string</code><br />
Called in the <code>hg</code> backend when <code>guards-string</code> is generated; the
<code>get-mq</code> style must be true (default).</p>
<p>This hook gets the names of any active <code>mq</code> guards.</p>
<p>When setting <code>ret</code> to non-zero, the string in
<code>${hook_com[guards-string]}</code> will be used in the <code>%g</code> escape in the
<code>patch-format</code> and <code>nopatch-format</code> styles.</p>
</li>
<li>
<p><code>no-vcs</code><br />
This hooks is called when no version control system was detected.</p>
<p>The ‘<code>hook_com</code>’ parameter is not used.</p>
</li>
<li>
<p><code>post-backend</code><br />
Called as soon as the backend has finished collecting information.</p>
<p>The ‘<code>hook_com</code>’ keys available are as for the <code>set-message</code> hook.</p>
</li>
<li>
<p><code>post-quilt</code><br />
Called after the <code>quilt</code> support is done. The following information
is passed as arguments to the hook: 1. the quilt-support mode
(‘addon’ or ‘standalone’); 2. the directory that contains the
patch series; 3. the directory that holds quilt’s status information
(the ‘.pc’ directory) or the string <code>&quot;-nopc-&quot;</code> if that directory
wasn’t found.</p>
<p>The ‘hook_com’ parameter is not used.</p>
</li>
<li>
<p><code>set-branch-format</code><br />
Called before ‘<code>branchformat</code>’ is set. The only argument to the hook
is the format that is configured at this point.</p>
<p>The ‘<code>hook_com</code>’ keys considered are ‘<code>branch</code>’ and ‘<code>revision</code>’.
They are set to the values figured out so far by <code>vcs_info</code> and any
change will be used directly when the actual replacement is done.</p>
<p>If <code>ret</code> is set to non-zero, the string in
<code>${hook_com[branch-replace]}</code> will be used unchanged as the ‘<code>%b</code>’
replacement in the variables set by <code>vcs_info</code>.</p>
</li>
<li>
<p><code>set-hgrev-format</code><br />
Called before a ‘<code>hgrevformat</code>’ is set. The only argument to the
hook is the format that is configured at this point.</p>
<p>The ‘<code>hook_com</code>’ keys considered are ‘<code>hash</code>’ and ‘<code>localrev</code>’. They
are set to the values figured out so far by <code>vcs_info</code> and any
change will be used directly when the actual replacement is done.</p>
<p>If <code>ret</code> is set to non-zero, the string in
<code>${hook_com[rev-replace]}</code> will be used unchanged as the ‘<code>%i</code>’
replacement in the variables set by <code>vcs_info</code>.</p>
</li>
<li>
<p><code>pre-addon-quilt</code><br />
This hook is used when <code>vcs_info</code>’s quilt functionality is active in
&quot;addon&quot; mode (quilt used on top of a real version control system).
It is activated right before any quilt specific action is taken.</p>
<p>Setting the ‘<code>ret</code>’ variable in this hook to a non-zero value avoids
any quilt specific actions from being run at all.</p>
</li>
<li>
<p><code>set-patch-format</code><br />
This hook is used to control some of the possible expansions in
<code>patch-format</code> and <code>nopatch-format</code> styles with patch queue systems
such as quilt, mqueue and the like.</p>
<p>This hook is used in the <code>git</code>, <code>hg</code> and <code>quilt</code> backends.</p>
<p>The hook allows the control of the <code>%p</code> (<code>${hook_com[applied]}</code>) and
<code>%u</code> (<code>${hook_com[unapplied]}</code>) expansion in all backends that use
the hook. With the mercurial backend, the <code>%g</code>
(<code>${hook_com[guards]}</code>) expansion is controllable in addition to
that.</p>
<p>If <code>ret</code> is set to non-zero, the string in
<code>${hook_com[patch-replace]}</code> will be used unchanged instead of an
expanded format from <code>patch-format</code> or <code>nopatch-format</code>.</p>
<p>This hook is, in concert with the <code>gen-applied-string</code> or
<code>gen-unapplied-string</code> hooks if they are defined, responsible for
<code>%</code>-escaping the final <code>patch-format</code> value for use in the prompt.
(See <a href="User-Contributions.html#vcs_005finfo-Oddities">Oddities</a>.)</p>
</li>
<li>
<p><code>set-message</code><br />
Called each time before a ‘<code>vcs_info_msg_``N``_</code>’ message is set. It
takes two arguments; the first being the ‘<code>N</code>’ in the message
variable name, the second is the currently configured <code>formats</code> or
<code>actionformats</code>.</p>
<p>There are a number of ‘<code>hook_com</code>’ keys, that are used here:
‘<code>action</code>’, ‘<code>branch</code>’, ‘<code>base</code>’, ‘<code>base-name</code>’, ‘<code>subdir</code>’,
‘<code>staged</code>’, ‘<code>unstaged</code>’, ‘<code>revision</code>’, ‘<code>misc</code>’, ‘<code>vcs</code>’ and one
‘<code>miscN</code>’ entry for each backend-specific data field (<code>N</code> starting
at zero). They are set to the values figured out so far by
<code>vcs_info</code> and any change will be used directly when the actual
replacement is done.</p>
<p>Since this hook is triggered multiple times (once for each
configured <code>formats</code> or <code>actionformats</code>), each of the ‘<code>hook_com</code>’
keys mentioned above (except for the <code>miscN</code> entries) has an
‘<code>_orig</code>’ counterpart, so even if you changed a value to your
liking you can still get the original value in the next run.
Changing the ‘<code>_orig</code>’ values is probably not a good idea.</p>
<p>If <code>ret</code> is set to non-zero, the string in <code>${hook_com[message]}</code>
will be used unchanged as the message by <code>vcs_info</code>.</p>
</li>
</ul>
<p>If all of this sounds rather confusing, take a look at
<a href="User-Contributions.html#vcs_005finfo-Examples">Examples</a> and also in the
<code>Misc/vcs_info-examples</code> file in the Zsh source. They contain some
explanatory code.</p>
<hr />
<p><span id="vcs_005finfo-Examples"></span> <span id="Examples"></span></p>
<h3 id="2658-examples"><a class="header" href="#2658-examples">26.5.8 Examples</a></h3>
<p>Don’t use <code>vcs_info</code> at all (even though it’s in your prompt):</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' enable NONE
</code></pre>
</div>
<p>Disable the backends for <code>bzr</code> and <code>svk</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' disable bzr svk
</code></pre>
</div>
<p>Disable everything <em>but</em> <code>bzr</code> and <code>svk</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*' enable bzr svk
</code></pre>
</div>
<p>Provide a special formats for <code>git</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:git:*' formats ' GIT, BABY! [%b]'
zstyle ':vcs_info:git:*' actionformats ' GIT ACTION! [%b|%a]'
</code></pre>
</div>
<p>All <code>%x</code> expansion in all sorts of formats (<code>formats</code>, <code>actionformats</code>,
<code>branchformat</code>, you name it) are done using the ‘<code>zformat</code>’ builtin from
the ‘<code>zsh/zutil</code>’ module. That means you can do everything with these
<code>%x</code> items what zformat supports. In particular, if you want something
that is really long to have a fixed width, like a hash in a mercurial
branchformat, you can do this: <code>%12.12i</code>. That’ll shrink the 40
character hash to its 12 leading characters. The form is actually
‘<code>%``min``.``max``x</code>’. More is possible. See <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a> for details.</p>
<p>Use the quicker <code>bzr</code> backend</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:bzr:*' use-simple true
</code></pre>
</div>
<p>If you do use <code>use-simple</code>, please report if it does
‘the-right-thing[tm]’.</p>
<p>Display the revision number in yellow for <code>bzr</code> and <code>svn</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:(svn|bzr):*' \
branchformat '%b%{'${fg[yellow]}'%}:%r'
</code></pre>
</div>
<p>If you want colors, make sure you enclose the color codes in
<code>%{``...``%}</code> if you want to use the string provided by <code>vcs_info</code> in
prompts.</p>
<p>Here is how to print the VCS information as a command (not in a prompt):</p>
<div class="example">
<pre><code class="language-example">alias vcsi='vcs_info command; vcs_info_lastmsg'
</code></pre>
</div>
<p>This way, you can even define different formats for output via
<code>vcs_info_lastmsg</code> in the ’<code>:vcs_info:*:command:*</code>’ namespace.</p>
<p>Now as promised, some code that uses hooks: say, you’d like to replace
the string ‘svn’ by ‘subversion’ in <code>vcs_info</code>’s <code>%s</code> <code>formats</code>
replacement.</p>
<p>First, we will tell <code>vcs_info</code> to call a function when populating the
message variables with the gathered information:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*+set-message:*' hooks svn2subversion
</code></pre>
</div>
<p>Nothing happens. Which is reasonable, since we didn’t define the actual
function yet. To see what the hooks subsystem is trying to do, enable
the ‘<code>debug</code>’ style:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*+*:*' debug true
</code></pre>
</div>
<p>That should give you an idea what is going on. Specifically, the
function that we are looking for is ‘<code>+vi-svn2subversion</code>’. Note, the
‘<code>+vi-</code>’ prefix. So, everything is in order, just as documented. When
you are done checking out the debugging output, disable it again:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:*+*:*' debug false
</code></pre>
</div>
<p>Now, let’s define the function:</p>
<div class="example">
<pre><code class="language-example">function +vi-svn2subversion() {
[[ ${hook_com[vcs_orig]} == svn ]] &amp;&amp; hook_com[vcs]=subversion
}
</code></pre>
</div>
<p>Simple enough. And it could have even been simpler, if only we had
registered our function in a less generic context. If we do it only in
the ‘<code>svn</code>’ backend’s context, we don’t need to test which the active
backend is:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:svn+set-message:*' hooks svn2subversion
</code></pre>
</div>
<div class="example">
<pre><code class="language-example">function +vi-svn2subversion() {
hook_com[vcs]=subversion
}
</code></pre>
</div>
<p>And finally a little more elaborate example, that uses a hook to create
a customised bookmark string for the <code>hg</code> backend.</p>
<p>Again, we start off by registering a function:</p>
<div class="example">
<pre><code class="language-example">zstyle ':vcs_info:hg+gen-hg-bookmark-string:*' hooks hgbookmarks
</code></pre>
</div>
<p>And then we define the ‘<code>+vi-hgbookmarks</code>’ function:</p>
<div class="example">
<pre><code class="language-example">function +vi-hgbookmarks() {
# The default is to connect all bookmark names by
# commas. This mixes things up a little.
# Imagine, there's one type of bookmarks that is
# special to you. Say, because it's *your* work.
# Those bookmarks look always like this: &quot;sh/*&quot;
# (because your initials are sh, for example).
# This makes the bookmarks string use only those
# bookmarks. If there's more than one, it
# concatenates them using commas.
# The bookmarks returned by `hg' are available in
# the function's positional parameters.
local s=&quot;${(Mj:,:)@:#sh/*}&quot;
# Now, the communication with the code that calls
# the hook functions is done via the hook_com[]
# hash. The key at which the `gen-hg-bookmark-string'
# hook looks is `hg-bookmark-string'. So:
hook_com[hg-bookmark-string]=$s
# And to signal that we want to use the string we
# just generated, set the special variable `ret' to
# something other than the default zero:
ret=1
return 0
}
</code></pre>
</div>
<p>Some longer examples and code snippets which might be useful are
available in the examples file located at Misc/vcs_info-examples in the
Zsh source directory.</p>
<p>This concludes our guided tour through zsh’s <code>vcs_info</code>.</p>
<hr />
<p><span id="Prompt-Themes"></span> <span id="Prompt-Themes-1"></span></p>
<h2 id="266-prompt-themes"><a class="header" href="#266-prompt-themes">26.6 Prompt Themes</a></h2>
<hr />
<p><span id="Installation-2"></span></p>
<h3 id="2661-installation"><a class="header" href="#2661-installation">26.6.1 Installation</a></h3>
<p>You should make sure all the functions from the <code>Functions/Prompts</code>
directory of the source distribution are available; they all begin with
the string ‘<code>prompt_</code>’ except for the special function‘<code>promptinit</code>’.
You also need the ‘<code>colors</code>’ and ‘<code>add-zsh-hook</code>’ functions from
<code>Functions/Misc</code>. All these functions may already be installed on your
system; if not, you will need to find them and copy them. The directory
should appear as one of the elements of the <code>fpath</code> array (this should
already be the case if they were installed), and at least the function
<code>promptinit</code> should be autoloaded; it will autoload the rest. Finally,
to initialize the use of the system you need to call the <code>promptinit</code>
function. The following code in your <code>.zshrc</code> will arrange for this;
assume the functions are stored in the directory <code>~/myfns</code>:</p>
<div class="example">
<pre><code class="language-example">fpath=(~/myfns $fpath)
autoload -U promptinit
promptinit
</code></pre>
</div>
<hr />
<p><span id="Theme-Selection"></span></p>
<h3 id="2662-theme-selection"><a class="header" href="#2662-theme-selection">26.6.2 Theme Selection</a></h3>
<p>Use the <code>prompt</code> command to select your preferred theme. This command
may be added to your <code>.zshrc</code> following the call to <code>promptinit</code> in
order to start zsh with a theme already selected.</p>
<ul>
<li>
<p><code>prompt</code> [ <code>-c</code> | <code>-l</code> ]<br />
<code>prompt</code> [ <code>-p</code> | <code>-h</code> ] [ <code>theme</code> ... ]<br />
<code>prompt</code> [ <code>-s</code> ] <code>theme</code> [ <code>arg</code> ... ]<br />
Set or examine the prompt theme. With no options and a <code>theme</code>
argument, the theme with that name is set as the current theme. The
available themes are determined at run time; use the <code>-l</code> option to
see a list. The special <code>theme</code> ‘<code>random</code>’ selects at random one of
the available themes and sets your prompt to that.</p>
<p>In some cases the <code>theme</code> may be modified by one or more arguments,
which should be given after the theme name. See the help for each
theme for descriptions of these arguments.</p>
<p>Options are:</p>
<ul>
<li>
<p><code>-c</code><br />
Show the currently selected theme and its parameters, if any.</p>
</li>
<li>
<p><code>-l</code><br />
List all available prompt themes.</p>
</li>
<li>
<p><code>-p</code><br />
Preview the theme named by <code>theme</code>, or all themes if no <code>theme</code>
is given.</p>
</li>
<li>
<p><code>-h</code><br />
Show help for the theme named by <code>theme</code>, or for the <code>prompt</code>
function if no <code>theme</code> is given.</p>
</li>
<li>
<p><code>-s</code><br />
Set <code>theme</code> as the current theme and save state.</p>
</li>
</ul>
</li>
<li>
<p><code>prompt_``theme``_setup</code><br />
Each available <code>theme</code> has a setup function which is called by the
<code>prompt</code> function to install that theme. This function may define
other functions as necessary to maintain the prompt, including
functions used to preview the prompt or provide help for its use.
You should not normally call a theme’s setup function directly.</p>
</li>
</ul>
<hr />
<p><span id="Utility-Themes"></span></p>
<h3 id="2663-utility-themes"><a class="header" href="#2663-utility-themes">26.6.3 Utility Themes</a></h3>
<ul>
<li>
<p><code>prompt off</code><br />
The theme ‘<code>off</code>’ sets all the prompt variables to minimal values
with no special effects.</p>
</li>
<li>
<p><code>prompt default</code><br />
The theme ‘<code>default</code>’ sets all prompt variables to the same state as
if an interactive zsh was started with no initialization files.</p>
</li>
<li>
<p><code>prompt restore</code><br />
The special theme ‘<code>restore</code>’ erases all theme settings and sets
prompt variables to their state before the first time the ‘<code>prompt</code>’
function was run, provided each theme has properly defined its
cleanup (see below).</p>
<p>Note that you can undo ‘<code>prompt off</code>’ and ‘<code>prompt default</code>’ with
‘<code>prompt restore</code>’, but a second restore does not undo the first.</p>
</li>
</ul>
<hr />
<p><span id="Writing-Themes"></span></p>
<h3 id="2664-writing-themes"><a class="header" href="#2664-writing-themes">26.6.4 Writing Themes</a></h3>
<p>The first step for adding your own theme is to choose a name for it, and
create a file ‘<code>prompt_name_setup</code>’ in a directory in your <code>fpath</code>, such
as <code>~/myfns</code> in the example above. The file should at minimum contain
assignments for the prompt variables that your theme wishes to modify.
By convention, themes use <code>PS1</code>, <code>PS2</code>, <code>RPS1</code>, etc., rather than the
longer <code>PROMPT</code> and <code>RPROMPT</code>.</p>
<p>The file is autoloaded as a function in the current shell context, so it
may contain any necessary commands to customize your theme, including
defining additional functions. To make some complex tasks easier, your
setup function may also do any of the following:</p>
<ul>
<li>
<p>Assign <code>prompt_opts</code><br />
The array <code>prompt_opts</code> may be assigned any of <code>&quot;bang&quot;</code>, <code>&quot;cr&quot;</code>,
<code>&quot;percent&quot;</code>, <code>&quot;sp&quot;</code>, and/or <code>&quot;subst&quot;</code> as values. The corresponding
setopts (<code>promptbang</code>, etc.) are turned on, all other prompt-related
options are turned off. The <code>prompt_opts</code> array preserves setopts
even beyond the scope of <code>localoptions</code>, should your function need
that.</p>
</li>
<li>
<p>Modify precmd and preexec<br />
Use of <code>add-zsh-hook</code> is recommended. The <code>precmd</code> and <code>preexec</code>
hooks are automatically adjusted if the prompt theme changes or is
disabled.</p>
</li>
<li>
<p>Declare cleanup<br />
If your function makes any other changes that should be undone when
the theme is disabled, your setup function may call</p>
<div class="example">
<pre><code class="language-example">prompt_cleanup command
</code></pre>
</div>
<p>where <code>command</code> should be suitably quoted. If your theme is ever
disabled or replaced by another, <code>command</code> is executed with <code>eval</code>.
You may declare more than one such cleanup hook.</p>
</li>
<li>
<p>Define preview<br />
Define or autoload a function <code>prompt_name_preview</code> to display a
simulated version of your prompt. A simple default previewer is
defined by <code>promptinit</code> for themes that do not define their own.
This preview function is called by ‘<code>prompt -p</code>’.</p>
</li>
<li>
<p>Provide help<br />
Define or autoload a function <code>prompt_name_help</code> to display
documentation or help text for your theme. This help function is
called by ‘<code>prompt -h</code>’.</p>
</li>
</ul>
<hr />
<p><span id="ZLE-Functions"></span> <span id="ZLE-Functions-1"></span></p>
<h2 id="267-zle-functions"><a class="header" href="#267-zle-functions">26.7 ZLE Functions</a></h2>
<hr />
<p><span id="Widgets"></span></p>
<h3 id="2671-widgets"><a class="header" href="#2671-widgets">26.7.1 Widgets</a></h3>
<p>These functions all implement user-defined ZLE widgets (see <a href="Zsh-Line-Editor.html#Zsh-Line-Editor">Zsh Line
Editor</a>) which can be bound to
keystrokes in interactive shells. To use them, your <code>.zshrc</code> should
contain lines of the form</p>
<div class="example">
<pre><code class="language-example">autoload function
zle -N function
</code></pre>
</div>
<p>followed by an appropriate <code>bindkey</code> command to associate the function
with a key sequence. Suggested bindings are described below.</p>
<ul>
<li>
<p>bash-style word functions<br />
If you are looking for functions to implement moving over and
editing words in the manner of bash, where only alphanumeric
characters are considered word characters, you can use the functions
described in the next section. The following is sufficient:</p>
<div class="example">
<pre><code class="language-example">autoload -U select-word-style
select-word-style bash
</code></pre>
</div>
<p><span id="index-forward_002dword_002dmatch"></span>
<span id="index-backward_002dword_002dmatch"></span>
<span id="index-kill_002dword_002dmatch"></span>
<span id="index-backward_002dkill_002dword_002dmatch"></span>
<span id="index-transpose_002dwords_002dmatch"></span>
<span id="index-capitalize_002dword_002dmatch"></span>
<span id="index-up_002dcase_002dword_002dmatch"></span>
<span id="index-down_002dcase_002dword_002dmatch"></span>
<span id="index-delete_002dwhole_002dword_002dmatch"></span>
<span id="index-select_002dword_002dmatch"></span>
<span id="index-select_002dword_002dstyle"></span>
<span id="index-match_002dword_002dcontext"></span>
<span id="index-match_002dwords_002dby_002dstyle"></span></p>
</li>
<li>
<p><code>forward-word-match</code>, <code>backward-word-match</code><br />
<code>kill-word-match</code>, <code>backward-kill-word-match</code><br />
<code>transpose-words-match</code>, <code>capitalize-word-match</code><br />
<code>up-case-word-match</code>, <code>down-case-word-match</code><br />
<code>delete-whole-word-match</code>, <code>select-word-match</code><br />
<code>select-word-style</code>, <code>match-word-context</code>, <code>match-words-by-style</code><br />
The first eight ‘<code>-match</code>’ functions are drop-in replacements for
the builtin widgets without the suffix. By default they behave in a
similar way. However, by the use of styles and the function
<code>select-word-style</code>, the way words are matched can be altered.
<code>select-word-match</code> is intended to be used as a text object in vi
mode but with custom word styles. For comparison, the widgets
described in <a href="Zsh-Line-Editor.html#Text-Objects">Text Objects</a> use
fixed definitions of words, compatible with the <code>vim</code> editor.</p>
<p>The simplest way of configuring the functions is to use
<code>select-word-style</code>, which can either be called as a normal function
with the appropriate argument, or invoked as a user-defined widget
that will prompt for the first character of the word style to be
used. The first time it is invoked, the first eight <code>-match</code>
functions will automatically replace the builtin versions, so they
do not need to be loaded explicitly.</p>
<p>The word styles available are as follows. Only the first character
is examined.</p>
<ul>
<li>
<p><code>bash</code><br />
Word characters are alphanumeric characters only.</p>
</li>
<li>
<p><code>normal</code><br />
As in normal shell operation: word characters are alphanumeric
characters plus any characters present in the string given by
the parameter <code>$WORDCHARS</code>.</p>
</li>
<li>
<p><code>shell</code><br />
Words are complete shell command arguments, possibly including
complete quoted strings, or any tokens special to the shell.</p>
</li>
<li>
<p><code>whitespace</code><br />
Words are any set of characters delimited by whitespace.</p>
</li>
<li>
<p><code>default</code><br />
Restore the default settings; this is usually the same as
‘<code>normal</code>’.</p>
</li>
</ul>
<p>All but ‘<code>default</code>’ can be input as an upper case character, which
has the same effect but with subword matching turned on. In this
case, words with upper case characters are treated specially: each
separate run of upper case characters, or an upper case character
followed by any number of other characters, is considered a word.
The style <code>subword-range</code> can supply an alternative character range
to the default ‘<code>[:upper:]</code>’; the value of the style is treated as
the contents of a ‘<code>[``...``]</code>’ pattern (note that the outer
brackets should not be supplied, only those surrounding named
ranges).</p>
<p>More control can be obtained using the <code>zstyle</code> command, as
described in <a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a>. Each style is
looked up in the context <code>:zle:``widget</code> where <code>widget</code> is the name
of the user-defined widget, not the name of the function
implementing it, so in the case of the definitions supplied by
<code>select-word-style</code> the appropriate contexts are
<code>:zle:forward-word</code>, and so on. The function <code>select-word-style</code>
itself always defines styles for the context ‘<code>:zle:*</code>’ which can be
overridden by more specific (longer) patterns as well as explicit
contexts.</p>
<p>The style <code>word-style</code> specifies the rules to use. This may have the
following values.</p>
<ul>
<li>
<p><code>normal</code><br />
Use the standard shell rules, i.e. alphanumerics and
<code>$WORDCHARS</code>, unless overridden by the styles <code>word-chars</code> or
<code>word-class</code>.</p>
</li>
<li>
<p><code>specified</code><br />
Similar to <code>normal</code>, but <em>only</em> the specified characters, and
not also alphanumerics, are considered word characters.</p>
</li>
<li>
<p><code>unspecified</code><br />
The negation of specified. The given characters are those which
will <em>not</em> be considered part of a word.</p>
</li>
<li>
<p><code>shell</code><br />
Words are obtained by using the syntactic rules for generating
shell command arguments. In addition, special tokens which are
never command arguments such as ‘<code>()</code>’ are also treated as
words.</p>
</li>
<li>
<p><code>whitespace</code><br />
Words are whitespace-delimited strings of characters.</p>
</li>
</ul>
<p>The first three of those rules usually use <code>$WORDCHARS</code>, but the
value in the parameter can be overridden by the style <code>word-chars</code>,
which works in exactly the same way as <code>$WORDCHARS</code>. In addition,
the style <code>word-class</code> uses character class syntax to group
characters and takes precedence over <code>word-chars</code> if both are set.
The <code>word-class</code> style does not include the surrounding brackets of
the character class; for example, ‘<code>-:[:alnum:]</code>’ is a valid
<code>word-class</code> to include all alphanumerics plus the characters ‘<code>-</code>’
and ‘<code>:</code>’. Be careful including ‘<code>]</code>’, ‘<code>^</code>’ and ‘<code>-</code>’ as these are
special inside character classes.</p>
<p><code>word-style</code> may also have ‘<code>-subword</code>’ appended to its value to
turn on subword matching, as described above.</p>
<p>The style <code>skip-chars</code> is mostly useful for <code>transpose-words</code> and
similar functions. If set, it gives a count of characters starting
at the cursor position which will not be considered part of the word
and are treated as space, regardless of what they actually are. For
example, if</p>
<div class="example">
<pre><code class="language-example">zstyle ':zle:transpose-words' skip-chars 1
</code></pre>
</div>
<p>has been set, and <code>transpose-words-match</code> is called with the cursor
on the <code>X</code> of <code>foo``X``bar</code>, where <code>X</code> can be any character, then
the resulting expression is <code>bar``X``foo</code>.</p>
<p>Finer grained control can be obtained by setting the style
<code>word-context</code> to an array of pairs of entries. Each pair of entries
consists of a <code>pattern</code> and a <code>subcontext</code>. The shell argument the
cursor is on is matched against each <code>pattern</code> in turn until one
matches; if it does, the context is extended by a colon and the
corresponding <code>subcontext</code>. Note that the test is made against the
original word on the line, with no stripping of quotes. Special
handling is done between words: the current context is examined and
if it contains the string <code>between</code> the word is set to a single
space; else if it is contains the string <code>back</code>, the word before the
cursor is considered, else the word after cursor is considered. Some
examples are given below.</p>
<p>The style <code>skip-whitespace-first</code> is only used with the
<code>forward-word</code> widget. If it is set to true, then <code>forward-word</code>
skips any non-word-characters, followed by any non-word-characters:
this is similar to the behaviour of other word-orientated widgets,
and also that used by other editors, however it differs from the
standard zsh behaviour. When using <code>select-word-style</code> the widget is
set in the context <code>:zle:*</code> to <code>true</code> if the word style is <code>bash</code>
and <code>false</code> otherwise. It may be overridden by setting it in the
more specific context <code>:zle:forward-word*</code>.</p>
<p>It is possible to create widgets with specific behaviour by defining
a new widget implemented by the appropriate generic function, then
setting a style for the context of the specific widget. For example,
the following defines a widget <code>backward-kill-space-word</code> using
<code>backward-kill-word-match</code>, the generic widget implementing
<code>backward-kill-word</code> behaviour, and ensures that the new widget
always implements space-delimited behaviour.</p>
<div class="example">
<pre><code class="language-example">zle -N backward-kill-space-word backward-kill-word-match
zstyle :zle:backward-kill-space-word word-style space
</code></pre>
</div>
<p>The widget <code>backward-kill-space-word</code> can now be bound to a key.</p>
<p>Here are some further examples of use of the styles, actually taken
from the simplified interface in <code>select-word-style</code>:</p>
<div class="example">
<pre><code class="language-example">zstyle ':zle:*' word-style standard
zstyle ':zle:*' word-chars ''
</code></pre>
</div>
<p>Implements bash-style word handling for all widgets, i.e. only
alphanumerics are word characters; equivalent to setting the
parameter <code>WORDCHARS</code> empty for the given context.</p>
<div class="example">
<pre><code class="language-example">style ':zle:*kill*' word-style space
</code></pre>
</div>
<p>Uses space-delimited words for widgets with the word ‘kill’ in the
name. Neither of the styles <code>word-chars</code> nor <code>word-class</code> is used in
this case.</p>
<p>Here are some examples of use of the <code>word-context</code> style to extend
the context.</p>
<div class="example">
<pre><code class="language-example">zstyle ':zle:*' word-context \
&quot;*/*&quot; filename &quot;[[:space:]]&quot; whitespace
zstyle ':zle:transpose-words:whitespace' word-style shell
zstyle ':zle:transpose-words:filename' word-style normal
zstyle ':zle:transpose-words:filename' word-chars ''
</code></pre>
</div>
<p>This provides two different ways of using <code>transpose-words</code>
depending on whether the cursor is on whitespace between words or on
a filename, here any word containing a <code>/</code>. On whitespace, complete
arguments as defined by standard shell rules will be transposed. In
a filename, only alphanumerics will be transposed. Elsewhere, words
will be transposed using the default style for
<code>:zle:transpose-words</code>.</p>
<p>The word matching and all the handling of <code>zstyle</code> settings is
actually implemented by the function <code>match-words-by-style</code>. This
can be used to create new user-defined widgets. The calling function
should set the local parameter <code>curcontext</code> to <code>:zle:``widget</code>,
create the local parameter <code>matched_words</code> and call
<code>match-words-by-style</code> with no arguments. On return, <code>matched_words</code>
will be set to an array with the elements: (1) the start of the line
(2) the word before the cursor (3) any non-word characters between
that word and the cursor (4) any non-word character at the cursor
position plus any remaining non-word characters before the next
word, including all characters specified by the <code>skip-chars</code> style,
(5) the word at or following the cursor (6) any non-word characters
following that word (7) the remainder of the line. Any of the
elements may be an empty string; the calling function should test
for this to decide whether it can perform its function.</p>
<p>If the variable <code>matched_words</code> is defined by the caller to
<code>match-words-by-style</code> as an associative array (<code>local -A matched_words</code>), then the seven values given above should be
retrieved from it as elements named <code>start</code>, <code>word-before-cursor</code>,
<code>ws-before-cursor</code>, <code>ws-after-cursor</code>, <code>word-after-cursor</code>,
<code>ws-after-word</code>, and <code>end</code>. In addition the element <code>is-word-start</code>
is 1 if the cursor is on the start of a word or subword, or on white
space before it (the cases can be distinguished by testing the
<code>ws-after-cursor</code> element) and 0 otherwise. This form is recommended
for future compatibility.</p>
<p>It is possible to pass options with arguments to
<code>match-words-by-style</code> to override the use of styles. The options
are:</p>
<ul>
<li>
<p><code>-w</code><br />
<code>word-style</code></p>
</li>
<li>
<p><code>-s</code><br />
<code>skip-chars</code></p>
</li>
<li>
<p><code>-c</code><br />
<code>word-class</code></p>
</li>
<li>
<p><code>-C</code><br />
<code>word-chars</code></p>
</li>
<li>
<p><code>-r</code><br />
<code>subword-range</code></p>
</li>
</ul>
<p>For example, <code>match-words-by-style -w shell -c 0</code> may be used to
extract the command argument around the cursor.</p>
<p>The <code>word-context</code> style is implemented by the function
<code>match-word-context</code>. This should not usually need to be called
directly.</p>
<p><span id="index-bracketed_002dpaste_002dmagic"></span></p>
</li>
<li>
<p><code>bracketed-paste-magic</code><br />
The <code>bracketed-paste</code> widget (see
<a href="Zsh-Line-Editor.html#Miscellaneous">Miscellaneous</a> in
<a href="Zsh-Line-Editor.html#Zle-Widgets">Widgets</a>) inserts pasted text
literally into the editor buffer rather than interpret it as
keystrokes. This disables some common usages where the self-insert
widget is replaced in order to accomplish some extra processing. An
example is the contributed <code>url-quote-magic</code> widget described below.</p>
<p>The <code>bracketed-paste-magic</code> widget is meant to replace
<code>bracketed-paste</code> with a wrapper that re-enables these self-insert
actions, and other actions as selected by zstyles. Therefore this
widget is installed with</p>
<div class="example">
<pre><code class="language-example">autoload -Uz bracketed-paste-magic
zle -N bracketed-paste bracketed-paste-magic
</code></pre>
</div>
<p>Other than enabling some widget processing, <code>bracketed-paste-magic</code>
attempts to replicate <code>bracketed-paste</code> as faithfully as possible.</p>
<p>The following zstyles may be set to control processing of pasted
text. All are looked up in the context ‘<code>:bracketed-paste-magic</code>’.</p>
<ul>
<li>
<p><code>active-widgets</code><br />
A list of patterns matching widget names that should be
activated during the paste. All other key sequences are
processed as self-insert-unmeta. The default is ‘<code>self-*</code>’ so
any user-defined widgets named with that prefix are active along
with the builtin self-insert.</p>
<p>If this style is not set (explicitly deleted) or set to an empty
value, no widgets are active and the pasted text is inserted
literally. If the value includes ‘<code>undefined-key</code>’, any unknown
sequences are discarded from the pasted text.</p>
</li>
<li>
<p><code>inactive-keys</code><br />
The inverse of <code>active-widgets</code>, a list of key sequences that
always use <code>self-insert-unmeta</code> even when bound to an active
widget. Note that this is a list of literal key sequences, not
patterns.</p>
</li>
<li>
<p><code>paste-init</code><br />
A list of function names, called in widget context (but not as
widgets). The functions are called in order until one of them
returns a non-zero status. The parameter ‘<code>PASTED</code>’ contains the
initial state of the pasted text. All other ZLE parameters such
as ‘<code>BUFFER</code>’ have their normal values and side-effects, and
full history is available, so for example <code>paste-init</code> functions
may move words from <code>BUFFER</code> into <code>PASTED</code> to make those words
visible to the <code>active-widgets</code>.</p>
<p>A non-zero return from a <code>paste-init</code> function does <em>not</em>
prevent the paste itself from proceeding.</p>
<p>Loading <code>bracketed-paste-magic</code> defines <code>backward-extend-paste</code>,
a helper function for use in <code>paste-init</code>.</p>
<div class="example">
<pre><code class="language-example">zstyle :bracketed-paste-magic paste-init \
backward-extend-paste
</code></pre>
</div>
<p>When a paste would insert into the middle of a word or append
text to a word already on the line, <code>backward-extend-paste</code>
moves the prefix from <code>LBUFFER</code> into <code>PASTED</code> so that the
<code>active-widgets</code> see the full word so far. This may be useful
with <code>url-quote-magic</code>.</p>
</li>
<li>
<p><code>paste-finish</code><br />
Another list of function names called in order until one returns
non-zero. These functions are called <em>after</em> the pasted text has
been processed by the <code>active-widgets</code>, but <em>before</em> it is
inserted into ‘<code>BUFFER</code>’. ZLE parameters have their normal
values and side-effects.</p>
<p>A non-zero return from a <code>paste-finish</code> function does <em>not</em>
prevent the paste itself from proceeding.</p>
<p>Loading <code>bracketed-paste-magic</code> also defines <code>quote-paste</code>, a
helper function for use in <code>paste-finish</code>.</p>
<div class="example">
<pre><code class="language-example">zstyle :bracketed-paste-magic paste-finish \
quote-paste
zstyle :bracketed-paste-magic:finish quote-style \
qqq
</code></pre>
</div>
<p>When the pasted text is inserted into <code>BUFFER</code>, it is quoted per
the <code>quote-style</code> value. To forcibly turn off the built-in
numeric prefix quoting of <code>bracketed-paste</code>, use:</p>
<div class="example">
<pre><code class="language-example">zstyle :bracketed-paste-magic:finish quote-style \
none
</code></pre>
</div>
</li>
</ul>
<p><em>Important:</em> During <code>active-widgets</code> processing of the paste (after
<code>paste-init</code> and before <code>paste-finish</code>), <code>BUFFER</code> starts empty and
history is restricted, so cursor motions, etc., may not pass outside
of the pasted content. Text assigned to <code>BUFFER</code> by the active
widgets is copied back into <code>PASTED</code> before <code>paste-finish</code>.</p>
<p><span id="index-copy_002dearlier_002dword"></span></p>
</li>
<li>
<p><code>copy-earlier-word</code><br />
This widget works like a combination of <code>insert-last-word</code> and
<code>copy-prev-shell-word</code>. Repeated invocations of the widget retrieve
earlier words on the relevant history line. With a numeric argument
<code>N</code>, insert the <code>N</code>th word from the history line; <code>N</code> may be
negative to count from the end of the line.</p>
<p>If <code>insert-last-word</code> has been used to retrieve the last word on a
previous history line, repeated invocations will replace that word
with earlier words from the same line.</p>
<p>Otherwise, the widget applies to words on the line currently being
edited. The <code>widget</code> style can be set to the name of another widget
that should be called to retrieve words. This widget must accept the
same three arguments as <code>insert-last-word</code>.</p>
<p><span id="index-cycle_002dcompletion_002dpositions"></span></p>
</li>
<li>
<p><code>cycle-completion-positions</code><br />
After inserting an unambiguous string into the command line, the new
function based completion system may know about multiple places in
this string where characters are missing or differ from at least one
of the possible matches. It will then place the cursor on the
position it considers to be the most interesting one, i.e. the one
where one can disambiguate between as many matches as possible with
as little typing as possible.</p>
<p>This widget allows the cursor to be easily moved to the other
interesting spots. It can be invoked repeatedly to cycle between all
positions reported by the completion system.</p>
<p><span id="index-delete_002dwhole_002dword_002dmatch-1"></span></p>
</li>
<li>
<p><code>delete-whole-word-match</code><br />
This is another function which works like the <code>-match</code> functions
described immediately above, i.e. using styles to decide the word
boundaries. However, it is not a replacement for any existing
function.</p>
<p>The basic behaviour is to delete the word around the cursor. There
is no numeric argument handling; only the single word around the
cursor is considered. If the widget contains the string <code>kill</code>, the
removed text will be placed in the cutbuffer for future yanking.
This can be obtained by defining <code>kill-whole-word-match</code> as follows:</p>
<div class="example">
<pre><code class="language-example">zle -N kill-whole-word-match delete-whole-word-match
</code></pre>
</div>
<p>and then binding the widget <code>kill-whole-word-match</code>.</p>
<p><span id="index-down_002dline_002dor_002dbeginning_002dsearch"></span>
<span id="index-up_002dline_002dor_002dbeginning_002dsearch"></span></p>
</li>
<li>
<p><code>up-line-or-beginning-search</code>, <code>down-line-or-beginning-search</code><br />
These widgets are similar to the builtin functions
<code>up-line-or-search</code> and <code>down-line-or-search</code>: if in a multiline
buffer they move up or down within the buffer, otherwise they search
for a history line matching the start of the current line. In this
case, however, they search for a line which matches the current line
up to the current cursor position, in the manner of
<code>history-beginning-search-backward</code> and <code>-forward</code>, rather than the
first word on the line.</p>
<p><span id="index-edit_002dcommand_002dline"></span></p>
</li>
<li>
<p><code>edit-command-line</code><br />
Edit the command line using your visual editor, as in <code>ksh</code>.</p>
<div class="example">
<pre><code class="language-example">bindkey -M vicmd v edit-command-line
</code></pre>
</div>
<p><span id="index-expand_002dabsolute_002dpath"></span></p>
</li>
<li>
<p><code>expand-absolute-path</code><br />
Expand the file name under the cursor to an absolute path, resolving
symbolic links. Where possible, the initial path segment is turned
into a named directory or reference to a user’s home directory.</p>
<p><span id="index-history_002dbeginning_002dsearch_002dbackward_002dend"></span>
<span id="index-history_002dbeginning_002dsearch_002dforward_002dend"></span></p>
</li>
<li>
<p><code>history-search-end</code><br />
This function implements the widgets
<code>history-beginning-search-backward-end</code> and
<code>history-beginning-search-forward-end</code>. These commands work by first
calling the corresponding builtin widget (see <a href="Zsh-Line-Editor.html#History-Control">History
Control</a>) and then moving the
cursor to the end of the line. The original cursor position is
remembered and restored before calling the builtin widget a second
time, so that the same search is repeated to look farther through
the history.</p>
<p>Although you <code>autoload</code> only one function, the commands to use it
are slightly different because it implements two widgets.</p>
<div class="example">
<pre><code class="language-example">zle -N history-beginning-search-backward-end \
history-search-end
zle -N history-beginning-search-forward-end \
history-search-end
bindkey '\e^P' history-beginning-search-backward-end
bindkey '\e^N' history-beginning-search-forward-end
</code></pre>
</div>
<p><span id="index-history_002dbeginning_002dsearch_002dmenu"></span></p>
</li>
<li>
<p><code>history-beginning-search-menu</code><br />
This function implements yet another form of history searching. The
text before the cursor is used to select lines from the history, as
for <code>history-beginning-search-backward</code> except that all matches are
shown in a numbered menu. Typing the appropriate digits inserts the
full history line. Note that leading zeroes must be typed (they are
only shown when necessary for removing ambiguity). The entire
history is searched; there is no distinction between forwards and
backwards.</p>
<p>With a numeric argument, the search is not anchored to the start of
the line; the string typed by the use may appear anywhere in the
line in the history.</p>
<p>If the widget name contains ‘<code>-end</code>’ the cursor is moved to the end
of the line inserted. If the widget name contains ‘<code>-space</code>’ any
space in the text typed is treated as a wildcard and can match
anything (hence a leading space is equivalent to giving a numeric
argument). Both forms can be combined, for example:</p>
<div class="example">
<pre><code class="language-example">zle -N history-beginning-search-menu-space-end \
history-beginning-search-menu
</code></pre>
</div>
<p><span id="index-history_002dpattern_002dsearch"></span>
<span id="index-history_002dpattern_002dsearch_002dbackward"></span>
<span id="index-history_002dpattern_002dsearch_002dforward"></span></p>
</li>
<li>
<p><code>history-pattern-search</code><br />
The function <code>history-pattern-search</code> implements widgets which
prompt for a pattern with which to search the history backwards or
forwards. The pattern is in the usual zsh format, however the first
character may be <code>^</code> to anchor the search to the start of the line,
and the last character may be <code>$</code> to anchor the search to the end of
the line. If the search was not anchored to the end of the line the
cursor is positioned just after the pattern found.</p>
<p>The commands to create bindable widgets are similar to those in the
example immediately above:</p>
<div class="example">
<pre><code class="language-example">autoload -U history-pattern-search
zle -N history-pattern-search-backward history-pattern-search
zle -N history-pattern-search-forward history-pattern-search
</code></pre>
</div>
<p><span id="index-incarg"></span>
<span id="index-incarg_002c-use-of"></span></p>
</li>
<li>
<p><code>incarg</code><br />
Typing the keystrokes for this widget with the cursor placed on or
to the left of an integer causes that integer to be incremented by
one. With a numeric argument, the number is incremented by the
amount of the argument (decremented if the numeric argument is
negative). The shell parameter <code>incarg</code> may be set to change the
default increment to something other than one.</p>
<div class="example">
<pre><code class="language-example">bindkey '^X+' incarg
</code></pre>
</div>
<p><span id="index-incremental_002dcomplete_002dword"></span></p>
</li>
<li>
<p><code>incremental-complete-word</code><br />
This allows incremental completion of a word. After starting this
command, a list of completion choices can be shown after every
character you type, which you can delete with <code>^H</code> or <code>DEL</code>.
Pressing return accepts the completion so far and returns you to
normal editing (that is, the command line is <em>not</em> immediately
executed). You can hit <code>TAB</code> to do normal completion, <code>^G</code> to abort
back to the state when you started, and <code>^D</code> to list the matches.</p>
<p>This works only with the new function based completion system.</p>
<div class="example">
<pre><code class="language-example">bindkey '^Xi' incremental-complete-word
</code></pre>
</div>
<p><span id="index-insert_002dcomposed_002dchar"></span></p>
</li>
<li>
<p><code>insert-composed-char</code><br />
This function allows you to compose characters that don’t appear on
the keyboard to be inserted into the command line. The command is
followed by two keys corresponding to ASCII characters (there is no
prompt). For accented characters, the two keys are a base character
followed by a code for the accent, while for other special
characters the two characters together form a mnemonic for the
character to be inserted. The two-character codes are a subset of
those given by RFC 1345 (see for example
<code>http://www.faqs.org/rfcs/rfc1345.html</code>).</p>
<p>The function may optionally be followed by up to two characters
which replace one or both of the characters read from the keyboard;
if both characters are supplied, no input is read. For example,
<code>insert-composed-char a:</code> can be used within a widget to insert an a
with umlaut into the command line. This has the advantages over use
of a</p>
<p>For best results zsh should have been built with support for
multibyte characters (configured with <code>–enable-multibyte</code>); however,
the function works for the limited range of characters available in
single-byte character sets such as ISO-8859-1.</p>
<p>The character is converted into the local representation and
inserted into the command line at the cursor position. (The
conversion is done within the shell, using whatever facilities the C
library provides.) With a numeric argument, the character and its
code are previewed in the status line</p>
<p>The function may be run outside zle in which case it prints the
character (together with a newline) to standard output. Input is
still read from keystrokes.</p>
<p>See <code>insert-unicode-char</code> for an alternative way of inserting
Unicode characters using their hexadecimal character number.</p>
<p>The set of accented characters is reasonably complete up to Unicode
character U+0180, the set of special characters less so. However, it
is very sporadic from that point. Adding new characters is easy,
however; see the function <code>define-composed-chars</code>. Please send any
additions to <code>zsh-workers@zsh.org</code>.</p>
<p>The codes for the second character when used to accent the first are
as follows. Note that not every character can take every accent.</p>
<ul>
<li>
<p><code>!</code><br />
Grave.</p>
</li>
<li>
<p><code>’</code><br />
Acute.</p>
</li>
<li>
<p><code>&gt;</code><br />
Circumflex.</p>
</li>
<li>
<p><code>?</code><br />
Tilde. (This is not <code>~</code> as RFC 1345 does not assume that
character is present on the keyboard.)</p>
</li>
<li>
<p><code>-</code><br />
Macron. (A horizontal bar over the base character.)</p>
</li>
<li>
<p><code>(</code><br />
Breve. (A shallow dish shape over the base character.)</p>
</li>
<li>
<p><code>.</code><br />
Dot above the base character, or in the case of <code>i</code> no dot, or
in the case of <code>L</code> and <code>l</code> a centered dot.</p>
</li>
<li>
<p><code>:</code><br />
Diaeresis (Umlaut).</p>
</li>
<li>
<p><code>c</code><br />
Cedilla.</p>
</li>
<li>
<p><code>_</code><br />
Underline, however there are currently no underlined characters.</p>
</li>
<li>
<p><code>/</code><br />
Stroke through the base character.</p>
</li>
<li>
<p><code>&quot;</code><br />
Double acute (only supported on a few letters).</p>
</li>
<li>
<p><code>;</code><br />
Ogonek. (A little forward facing hook at the bottom right of the
character.)</p>
</li>
<li>
<p><code>&lt;</code><br />
Caron. (A little v over the letter.)</p>
</li>
<li>
<p><code>0</code><br />
Circle over the base character.</p>
</li>
<li>
<p><code>2</code><br />
Hook over the base character.</p>
</li>
<li>
<p><code>9</code><br />
Horn over the base character.</p>
</li>
</ul>
<p>The most common characters from the Arabic, Cyrillic, Greek and
Hebrew alphabets are available; consult RFC 1345 for the appropriate
sequences. In addition, a set of two letter codes not in RFC 1345
are available for the double-width characters corresponding to ASCII
characters from <code>!</code> to <code>~</code> (0x21 to 0x7e) by preceding the character
with <code>^</code>, for example <code>^A</code> for a double-width <code>A</code>.</p>
<p>The following other two-character sequences are understood.</p>
<ul>
<li>
<p>ASCII characters<br />
These are already present on most keyboards:</p>
<ul>
<li>
<p><code>&lt;(</code><br />
Left square bracket</p>
</li>
<li>
<p><code>//</code><br />
Backslash (solidus)</p>
</li>
<li>
<p><code>)&gt;</code><br />
Right square bracket</p>
</li>
<li>
<p><code>(!</code><br />
Left brace (curly bracket)</p>
</li>
<li>
<p><code>!!</code><br />
Vertical bar (pipe symbol)</p>
</li>
<li>
<p><code>!)</code><br />
Right brace (curly bracket)</p>
</li>
<li>
<p><code>’?</code><br />
Tilde</p>
</li>
</ul>
</li>
<li>
<p>Special letters<br />
Characters found in various variants of the Latin alphabet:</p>
<ul>
<li>
<p><code>ss</code><br />
Eszett (scharfes S)</p>
</li>
<li>
<p><code>D-</code>, <code>d-</code><br />
Eth</p>
</li>
<li>
<p><code>TH</code>, <code>th</code><br />
Thorn</p>
</li>
<li>
<p><code>kk</code><br />
Kra</p>
</li>
<li>
<p><code>’n</code><br />
’n</p>
</li>
<li>
<p><code>NG</code>, <code>ng</code><br />
Ng</p>
</li>
<li>
<p><code>OI</code>, <code>oi</code><br />
Oi</p>
</li>
<li>
<p><code>yr</code><br />
yr</p>
</li>
<li>
<p><code>ED</code><br />
ezh</p>
</li>
</ul>
</li>
<li>
<p>Currency symbols</p>
<ul>
<li>
<p><code>Ct</code><br />
Cent</p>
</li>
<li>
<p><code>Pd</code><br />
Pound sterling (also lira and others)</p>
</li>
<li>
<p><code>Cu</code><br />
Currency</p>
</li>
<li>
<p><code>Ye</code><br />
Yen</p>
</li>
<li>
<p><code>Eu</code><br />
Euro (N.B. not in RFC 1345)</p>
</li>
</ul>
</li>
<li>
<p>Punctuation characters<br />
References to &quot;right&quot; quotes indicate the shape (like a 9 rather
than 6) rather than their grammatical use. (For example, a
&quot;right&quot; low double quote is used to open quotations in German.)</p>
<ul>
<li>
<p><code>!I</code><br />
Inverted exclamation mark</p>
</li>
<li>
<p><code>BB</code><br />
Broken vertical bar</p>
</li>
<li>
<p><code>SE</code><br />
Section</p>
</li>
<li>
<p><code>Co</code><br />
Copyright</p>
</li>
<li>
<p><code>-a</code><br />
Spanish feminine ordinal indicator</p>
</li>
<li>
<p><code>&lt;&lt;</code><br />
Left guillemet</p>
</li>
<li>
<p><code>-``-</code><br />
Soft hyphen</p>
</li>
<li>
<p><code>Rg</code><br />
Registered trade mark</p>
</li>
<li>
<p><code>PI</code><br />
Pilcrow (paragraph)</p>
</li>
<li>
<p><code>-o</code><br />
Spanish masculine ordinal indicator</p>
</li>
<li>
<p><code>&gt;&gt;</code><br />
Right guillemet</p>
</li>
<li>
<p><code>?I</code><br />
Inverted question mark</p>
</li>
<li>
<p><code>-1</code><br />
Hyphen</p>
</li>
<li>
<p><code>-N</code><br />
En dash</p>
</li>
<li>
<p><code>-M</code><br />
Em dash</p>
</li>
<li>
<p><code>-3</code><br />
Horizontal bar</p>
</li>
<li>
<p><code>:3</code><br />
Vertical ellipsis</p>
</li>
<li>
<p><code>.3</code><br />
Horizontal midline ellipsis</p>
</li>
<li>
<p><code>!2</code><br />
Double vertical line</p>
</li>
<li>
<p><code>=2</code><br />
Double low line</p>
</li>
<li>
<p><code>’6</code><br />
Left single quote</p>
</li>
<li>
<p><code>’9</code><br />
Right single quote</p>
</li>
<li>
<p><code>.9</code><br />
&quot;Right&quot; low quote</p>
</li>
<li>
<p><code>9’</code><br />
Reversed &quot;right&quot; quote</p>
</li>
<li>
<p><code>&quot;6</code><br />
Left double quote</p>
</li>
<li>
<p><code>&quot;9</code><br />
Right double quote</p>
</li>
<li>
<p><code>:9</code><br />
&quot;Right&quot; low double quote</p>
</li>
<li>
<p><code>9&quot;</code><br />
Reversed &quot;right&quot; double quote</p>
</li>
<li>
<p><code>/-</code><br />
Dagger</p>
</li>
<li>
<p><code>/=</code><br />
Double dagger</p>
</li>
</ul>
</li>
<li>
<p>Mathematical symbols</p>
<ul>
<li>
<p><code>DG</code><br />
Degree</p>
</li>
<li>
<p><code>-2</code>, <code>+-</code>, <code>-+</code><br />
- sign, +/- sign, -/+ sign</p>
</li>
<li>
<p><code>2S</code><br />
Superscript 2</p>
</li>
<li>
<p><code>3S</code><br />
Superscript 3</p>
</li>
<li>
<p><code>1S</code><br />
Superscript 1</p>
</li>
<li>
<p><code>My</code><br />
Micro</p>
</li>
<li>
<p><code>.M</code><br />
Middle dot</p>
</li>
<li>
<p><code>14</code><br />
Quarter</p>
</li>
<li>
<p><code>12</code><br />
Half</p>
</li>
<li>
<p><code>34</code><br />
Three quarters</p>
</li>
<li>
<p><code>*X</code><br />
Multiplication</p>
</li>
<li>
<p><code>-:</code><br />
Division</p>
</li>
<li>
<p><code>%0</code><br />
Per mille</p>
</li>
<li>
<p><code>FA</code>, <code>TE</code>, <code>/0</code><br />
For all, there exists, empty set</p>
</li>
<li>
<p><code>dP</code>, <code>DE</code>, <code>NB</code><br />
Partial derivative, delta (increment), del (nabla)</p>
</li>
<li>
<p><code>(-</code>, <code>-)</code><br />
Element of, contains</p>
</li>
<li>
<p><code>*P</code>, <code>+Z</code><br />
Product, sum</p>
</li>
<li>
<p><code>*-</code>, <code>Ob</code>, <code>Sb</code><br />
Asterisk, ring, bullet</p>
</li>
<li>
<p><code>RT</code>, <code>0(</code>, <code>00</code><br />
Root sign, proportional to, infinity</p>
</li>
</ul>
</li>
<li>
<p>Other symbols</p>
<ul>
<li>
<p><code>cS</code>, <code>cH</code>, <code>cD</code>, <code>cC</code><br />
Card suits: spades, hearts, diamonds, clubs</p>
</li>
<li>
<p><code>Md</code>, <code>M8</code>, <code>M2</code>, <code>Mb</code>, <code>Mx</code>, <code>MX</code><br />
Musical notation: crotchet (quarter note), quaver (eighth
note), semiquavers (sixteenth notes), flag sign, natural
sign, sharp sign</p>
</li>
<li>
<p><code>Fm</code>, <code>Ml</code><br />
Female, male</p>
</li>
</ul>
</li>
<li>
<p>Accents on their own</p>
<ul>
<li>
<p><code>’&gt;</code><br />
Circumflex (same as caret, <code>^</code>)</p>
</li>
<li>
<p><code>’!</code><br />
Grave (same as backtick, <code>‘</code>)</p>
</li>
<li>
<p><code>’,</code><br />
Cedilla</p>
</li>
<li>
<p><code>’:</code><br />
Diaeresis (Umlaut)</p>
</li>
<li>
<p><code>’m</code><br />
Macron</p>
</li>
<li>
<p><code>”</code><br />
Acute</p>
</li>
</ul>
</li>
</ul>
<p><span id="index-insert_002dfiles"></span></p>
</li>
<li>
<p><code>insert-files</code><br />
This function allows you type a file pattern, and see the results of
the expansion at each step. When you hit return, all expansions are
inserted into the command line.</p>
<div class="example">
<pre><code class="language-example">bindkey '^Xf' insert-files
</code></pre>
</div>
<p><span id="index-insert_002dunicode_002dchar"></span></p>
</li>
<li>
<p><code>insert-unicode-char</code><br />
When first executed, the user inputs a set of hexadecimal digits.
This is terminated with another call to <code>insert-unicode-char</code>. The
digits are then turned into the corresponding Unicode character. For
example, if the widget is bound to <code>^XU</code>, the character sequence
‘<code>^XU 4 c ^XU</code>’ inserts <code>L</code> (Unicode U+004c).</p>
<p>See <code>insert-composed-char</code> for a way of inserting characters using a
two-character mnemonic.</p>
<p><span id="index-narrow_002dto_002dregion"></span>
<span id="index-narrow_002dto_002dregion_002dinvisible"></span></p>
</li>
<li>
<p><code>narrow-to-region </code>[ <code>-p</code> <code>pre</code> ] [ <code>-P</code> <code>post</code> ]<br />
<code>                 </code>[ <code>-S</code> <code>statepm</code> | <code>-R</code> <code>statepm</code> | [ <code>-l</code>
<code>lbufvar</code> ] [ <code>-r</code> <code>rbufvar</code> ] ]<br />
<code>                 </code>[ <code>-n</code> ] [ <code>start</code> <code>end</code> ]<br />
<code>narrow-to-region-invisible</code><br />
<code>predict-on</code><br />
This set of functions implements predictive typing using history
search. After <code>predict-on</code>, typing characters causes the editor to
look backward in the history for the first line beginning with what
you have typed so far. After <code>predict-off</code>, editing returns to
normal for the line found. In fact, you often don’t even need to use
<code>predict-off</code>, because if the line doesn’t match something in the
history, adding a key performs standard completion, and then inserts
itself if no completions were found. However, editing in the middle
of a line is liable to confuse prediction; see the <code>toggle</code> style
below.</p>
<p>With the function based completion system (which is needed for
this), you should be able to type <code>TAB</code> at almost any point to
advance the cursor to the next ‘‘interesting’’ character position
(usually the end of the current word, but sometimes somewhere in the
middle of the word). And of course as soon as the entire line is
what you want, you can accept with return, without needing to move
the cursor to the end first.</p>
<p>The first time <code>predict-on</code> is used, it creates several additional
widget functions:</p>
<ul>
<li>
<p><code>delete-backward-and-predict</code><br />
Replaces the <code>backward-delete-char</code> widget. You do not need to
bind this yourself.</p>
</li>
<li>
<p><code>insert-and-predict</code><br />
Implements predictive typing by replacing the <code>self-insert</code>
widget. You do not need to bind this yourself.</p>
</li>
<li>
<p><code>predict-off</code><br />
Turns off predictive typing.</p>
</li>
</ul>
<p>Although you <code>autoload</code> only the <code>predict-on</code> function, it is
necessary to create a keybinding for <code>predict-off</code> as well.</p>
<div class="example">
<pre><code class="language-example">zle -N predict-on
zle -N predict-off
bindkey '^X^Z' predict-on
bindkey '^Z' predict-off
</code></pre>
</div>
<p><span id="index-read_002dfrom_002dminibuffer"></span></p>
</li>
<li>
<p><code>read-from-minibuffer</code><br />
This is most useful when called as a function from inside a widget,
but will work correctly as a widget in its own right. It prompts for
a value below the current command line; a value may be input using
all of the standard zle operations (and not merely the restricted
set available when executing, for example, <code>execute-named-cmd</code>). The
value is then returned to the calling function in the parameter
<code>$REPLY</code> and the editing buffer restored to its previous state. If
the read was aborted by a keyboard break (typically <code>^G</code>), the
function returns status 1 and <code>$REPLY</code> is not set.</p>
<p>If one argument is supplied to the function it is taken as a prompt,
otherwise ‘<code>? </code>’ is used. If two arguments are supplied, they are
the prompt and the initial value of <code>$LBUFFER</code>, and if a third
argument is given it is the initial value of <code>$RBUFFER</code>. This
provides a default value and starting cursor placement. Upon return
the entire buffer is the value of <code>$REPLY</code>.</p>
<p>One option is available: ‘<code>-k</code> <code>num</code>’ specifies that <code>num</code>
characters are to be read instead of a whole line. The line editor
is not invoked recursively in this case, so depending on the
terminal settings the input may not be visible, and only the input
keys are placed in <code>$REPLY</code>, not the entire buffer. Note that unlike
the <code>read</code> builtin <code>num</code> must be given; there is no default.</p>
<p>The name is a slight misnomer, as in fact the shell’s own minibuffer
is not used. Hence it is still possible to call <code>executed-named-cmd</code>
and similar functions while reading a value.</p>
<p><span id="index-replace_002dargument"></span>
<span id="index-replace_002dargument_002dedit"></span></p>
</li>
<li>
<p><code>replace-argument</code>, <code>replace-argument-edit</code><br />
The function <code>replace-argument</code> can be used to replace a command
line argument in the current command line or, if the current command
line is empty, in the last command line executed (the new command
line is not executed). Arguments are as delimited by standard shell
syntax,</p>
<p>If a numeric argument is given, that specifies the argument to be
replaced. 0 means the command name, as in history expansion. A
negative numeric argument counts backward from the last word.</p>
<p>If no numeric argument is given, the current argument is replaced;
this is the last argument if the previous history line is being
used.</p>
<p>The function prompts for a replacement argument.</p>
<p>If the widget contains the string <code>edit</code>, for example is defined as</p>
<div class="example">
<pre><code class="language-example">zle -N replace-argument-edit replace-argument
</code></pre>
</div>
<p>then the function presents the current value of the argument for
editing, otherwise the editing buffer for the replacement is
initially empty.</p>
<p><span id="index-replace_002dstring"></span>
<span id="index-replace_002dstring_002dagain"></span>
<span id="index-replace_002dpattern"></span></p>
</li>
<li>
<p><code>replace-string</code>, <code>replace-pattern</code><br />
<code>replace-string-again</code>, <code>replace-pattern-again</code><br />
The function <code>replace-string</code> implements three widgets. If defined
under the same name as the function, it prompts for two strings; the
first (source) string will be replaced by the second everywhere it
occurs in the line editing buffer.</p>
<p>If the widget name contains the word ‘<code>pattern</code>’, for example by
defining the widget using the command ‘<code>zle -N replace-pattern replace-string</code>’, then the matching is performed using zsh patterns.
All zsh extended globbing patterns can be used in the source string;
note that unlike filename generation the pattern does not need to
match an entire word, nor do glob qualifiers have any effect. In
addition, the replacement string can contain parameter or command
substitutions. Furthermore, a ‘<code>&amp;</code>’ in the replacement string will
be replaced with the matched source string, and a backquoted digit
‘<code>\``N</code>’ will be replaced by the <code>N</code>th parenthesised expression
matched. The form ‘<code>\{``N``}</code>’ may be used to protect the digit from
following digits.</p>
<p>If the widget instead contains the word ‘<code>regex</code>’ (or ‘<code>regexp</code>’),
then the matching is performed using regular expressions, respecting
the setting of the option <code>RE_MATCH_PCRE</code> (see the description of
the function <code>regexp-replace</code> below). The special replacement
facilities described above for pattern matching are available.</p>
<p>By default the previous source or replacement string will not be
offered for editing. However, this feature can be activated by
setting the style <code>edit-previous</code> in the context <code>:zle:``widget</code>
(for example, <code>:zle:replace-string</code>) to <code>true</code>. In addition, a
positive numeric argument forces the previous values to be offered,
a negative or zero argument forces them not to be.</p>
<p>The function <code>replace-string-again</code> can be used to repeat the
previous replacement; no prompting is done. As with
<code>replace-string</code>, if the name of the widget contains the word
‘<code>pattern</code>’ or ‘<code>regex</code>’, pattern or regular expression matching
is performed, else a literal string replacement. Note that the
previous source and replacement text are the same whether pattern,
regular expression or string matching is used.</p>
<p>In addition, <code>replace-string</code> shows the previous replacement above
the prompt, so long as there was one during the current session; if
the source string is empty, that replacement will be repeated
without the widget prompting for a replacement string.</p>
<p>For example, starting from the line:</p>
<div class="example">
<pre><code class="language-example">print This line contains fan and fond
</code></pre>
</div>
<p>and invoking <code>replace-pattern</code> with the source string ‘<code>f(?)n</code>’ and
the replacement string ‘<code>c\1r</code>’ produces the not very useful line:</p>
<div class="example">
<pre><code class="language-example">print This line contains car and cord
</code></pre>
</div>
<p>The range of the replacement string can be limited by using the
<code>narrow-to-region-invisible</code> widget. One limitation of the current
version is that <code>undo</code> will cycle through changes to the replacement
and source strings before undoing the replacement itself.</p>
<p><span id="index-send_002dinvisible"></span></p>
</li>
<li>
<p><code>send-invisible</code><br />
This is similar to read-from-minibuffer in that it may be called as
a function from a widget or as a widget of its own, and
interactively reads input from the keyboard. However, the input
being typed is concealed and a string of asterisks (‘<code>*</code>’) is shown
instead. The value is saved in the parameter <code>$INVISIBLE</code> to which a
reference is inserted into the editing buffer at the restored cursor
position. If the read was aborted by a keyboard break (typically
<code>^G</code>) or another escape from editing such as <code>push-line</code>,
<code>$INVISIBLE</code> is set to empty and the original buffer is restored
unchanged.</p>
<p>If one argument is supplied to the function it is taken as a prompt,
otherwise ‘<code>Non-echoed text: </code>’ is used (as in emacs). If a second
and third argument are supplied they are used to begin and end the
reference to <code>$INVISIBLE</code> that is inserted into the buffer. The
default is to open with <code>${</code>, then <code>INVISIBLE</code>, and close with <code>}</code>,
but many other effects are possible.</p>
<p><span id="index-smart_002dinsert_002dlast_002dword"></span></p>
</li>
<li>
<p><code>smart-insert-last-word</code><br />
This function may replace the <code>insert-last-word</code> widget, like so:</p>
<div class="example">
<pre><code class="language-example">zle -N insert-last-word smart-insert-last-word
</code></pre>
</div>
<p>With a numeric argument, or when passed command line arguments in a
call from another widget, it behaves like <code>insert-last-word</code>, except
that words in comments are ignored when <code>INTERACTIVE_COMMENTS</code> is
set.</p>
<p>Otherwise, the rightmost ‘‘interesting’’ word from the previous
command is found and inserted. The default definition of
‘‘interesting’’ is that the word contains at least one
alphabetic character, slash, or backslash. This definition may be
overridden by use of the <code>match</code> style. The context used to look up
the style is the widget name, so usually the context is
<code>:insert-last-word</code>. However, you can bind this function to
different widgets to use different patterns:</p>
<div class="example">
<pre><code class="language-example">zle -N insert-last-assignment smart-insert-last-word
zstyle :insert-last-assignment match '[[:alpha:]][][[:alnum:]]#=*'
bindkey '\e=' insert-last-assignment
</code></pre>
</div>
<p>If no interesting word is found and the <code>auto-previous</code> style is set
to a true value, the search continues upward through the history.
When <code>auto-previous</code> is unset or false (the default), the widget
must be invoked repeatedly in order to search earlier history lines.</p>
<p><span id="index-transpose_002dlines"></span></p>
</li>
<li>
<p><code>transpose-lines</code><br />
Only useful with a multi-line editing buffer; the lines here are
lines within the current on-screen buffer, not history lines. The
effect is similar to the function of the same name in Emacs.</p>
<p>Transpose the current line with the previous line and move the
cursor to the start of the next line. Repeating this (which can be
done by providing a positive numeric argument) has the effect of
moving the line above the cursor down by a number of lines.</p>
<p>With a negative numeric argument, requires two lines above the
cursor. These two lines are transposed and the cursor moved to the
start of the previous line. Using a numeric argument less than -1
has the effect of moving the line above the cursor up by minus that
number of lines.</p>
<p><span id="index-url_002dquote_002dmagic"></span></p>
</li>
<li>
<p><code>url-quote-magic</code><br />
This widget replaces the built-in <code>self-insert</code> to make it easier to
type URLs as command line arguments. As you type, the input
character is analyzed and, if it may need quoting, the current word
is checked for a URI scheme. If one is found and the current word is
not already in quotes, a backslash is inserted before the input
character.</p>
<p>Styles to control quoting behavior:</p>
<ul>
<li>
<p><code>url-metas</code><br />
This style is looked up in the context
‘<code>:url-quote-magic:``scheme</code>’ (where <code>scheme</code> is that of the
current URL, e.g. &quot;<code>ftp</code>&quot;). The value is a string listing the
characters to be treated as globbing metacharacters when
appearing in a URL using that scheme. The default is to quote
all zsh extended globbing characters, excluding ’<code>&lt;</code>’ and ’<code>&gt;</code>’
but including braces (as in brace expansion). See also
<code>url-seps</code>.</p>
</li>
<li>
<p><code>url-seps</code><br />
Like <code>url-metas</code>, but lists characters that should be considered
command separators, redirections, history references, etc. The
default is to quote the standard set of shell separators,
excluding those that overlap with the extended globbing
characters, but including ’<code>&lt;</code>’ and ’<code>&gt;</code>’ and the first
character of <code>$histchars</code>.</p>
</li>
<li>
<p><code>url-globbers</code><br />
This style is looked up in the context ‘<code>:url-quote-magic</code>’. The
values form a list of command names that are expected to do
their own globbing on the URL string. This implies that they are
aliased to use the ‘<code>noglob</code>’ modifier. When the first word on
the line matches one of the values <em>and</em> the URL refers to a
local file (see <code>url-local-schema</code>), only the <code>url-seps</code>
characters are quoted; the <code>url-metas</code> are left alone, allowing
them to affect command-line parsing, completion, etc. The
default values are a literal ‘<code>noglob</code>’ plus (when the
<code>zsh/parameter</code> module is available) any commands aliased to the
helper function ‘<code>urlglobber</code>’ or its alias ‘<code>globurl</code>’.</p>
</li>
<li>
<p><code>url-local-schema</code><br />
This style is always looked up in the context ‘<code>:urlglobber</code>’,
even though it is used by both url-quote-magic and urlglobber.
The values form a list of URI schema that should be treated as
referring to local files by their real local path names, as
opposed to files which are specified relative to a
web-server-defined document root. The defaults are &quot;<code>ftp</code>&quot; and
&quot;<code>file</code>&quot;.</p>
</li>
<li>
<p><code>url-other-schema</code><br />
Like <code>url-local-schema</code>, but lists all other URI schema upon
which <code>urlglobber</code> and <code>url-quote-magic</code> should act. If the URI
on the command line does not have a scheme appearing either in
this list or in <code>url-local-schema</code>, it is not magically quoted.
The default values are &quot;<code>http</code>&quot;, &quot;<code>https</code>&quot;, and &quot;<code>ftp</code>&quot;. When a
scheme appears both here and in <code>url-local-schema</code>, it is quoted
differently depending on whether the command name appears in
<code>url-globbers</code>.</p>
</li>
</ul>
<p>Loading <code>url-quote-magic</code> also defines a helper function
‘<code>urlglobber</code>’ and aliases ‘<code>globurl</code>’ to ‘<code>noglob urlglobber</code>’.
This function takes a local URL apart, attempts to pattern-match the
local file portion of the URL path, and then puts the results back
into URL format again.</p>
<p><span id="index-vi_002dpipe"></span></p>
</li>
<li>
<p><code>vi-pipe</code><br />
This function reads a movement command from the keyboard and then
prompts for an external command. The part of the buffer covered by
the movement is piped to the external command and then replaced by
the command’s output. If the movement command is bound to vi-pipe,
the current line is used.</p>
<p>The function serves as an example for reading a vi movement command
from within a user-defined widget.</p>
<p><span id="index-which_002dcommand-1"></span></p>
</li>
<li>
<p><code>which-command</code><br />
This function is a drop-in replacement for the builtin widget
<code>which-command</code>. It has enhanced behaviour, in that it correctly
detects whether or not the command word needs to be expanded as an
alias; if so, it continues tracing the command word from the
expanded alias until it reaches the command that will be executed.</p>
<p>The style <code>whence</code> is available in the context <code>:zle:$WIDGET</code>; this
may be set to an array to give the command and options that will be
used to investigate the command word found. The default is <code>whence -c</code>.</p>
<p><span id="index-zcalc_002dauto_002dinsert"></span></p>
</li>
<li>
<p><code>zcalc-auto-insert</code><br />
This function is useful together with the <code>zcalc</code> function described
in <a href="User-Contributions.html#Mathematical-Functions">Mathematical Functions</a>. It should be
bound to a key representing a binary operator such as ‘<code>+</code>’, ‘<code>-</code>’,
‘<code>*</code>’ or ‘<code>/</code>’. When running in zcalc, if the key occurs at the
start of the line or immediately following an open parenthesis, the
text <code>&quot;ans &quot;</code> is inserted before the representation of the key
itself. This allows easy use of the answer from the previous
calculation in the current line. The text to be inserted before the
symbol typed can be modified by setting the variable
<code>ZCALC_AUTO_INSERT_PREFIX</code>.</p>
<p>Hence, for example, typing ‘<code>+12</code>’ followed by return adds 12 to the
previous result.</p>
<p>If zcalc is in RPN mode (<code>-r</code> option) the effect of this binding is
automatically suppressed as operators alone on a line are
meaningful.</p>
<p>When not in zcalc, the key simply inserts the symbol itself.</p>
</li>
</ul>
<hr />
<p><span id="Utility-Functions"></span></p>
<h3 id="2672-utility-functions"><a class="header" href="#2672-utility-functions">26.7.2 Utility Functions</a></h3>
<p>These functions are useful in constructing widgets. They should be
loaded with ‘<code>autoload -U</code> <code>function</code>’ and called as indicated from
user-defined widgets.</p>
<p><span id="index-split_002dshell_002darguments"></span></p>
<p><code>split-shell-arguments</code></p>
<p>This function splits the line currently being edited into shell
arguments and whitespace. The result is stored in the array <code>reply</code>. The
array contains all the parts of the line in order, starting with any
whitespace before the first argument, and finishing with any whitespace
after the last argument. Hence (so long as the option <code>KSH_ARRAYS</code> is
not set) whitespace is given by odd indices in the array and arguments
by even indices. Note that no stripping of quotes is done; joining
together all the elements of <code>reply</code> in order is guaranteed to produce
the original line.</p>
<p>The parameter <code>REPLY</code> is set to the index of the word in <code>reply</code> which
contains the character after the cursor, where the first element has
index 1. The parameter <code>REPLY2</code> is set to the index of the character
under the cursor in that word, where the first character has index 1.</p>
<p>Hence <code>reply</code>, <code>REPLY</code> and <code>REPLY2</code> should all be made local to the
enclosing function.</p>
<p>See the function <code>modify-current-argument</code>, described below, for an
example of how to call this function.</p>
<p><span id="index-modify_002dcurrent_002dargument"></span></p>
<p><code>modify-current-argument</code> [ <code>expr-using-``$ARG</code> | <code>func</code> ]</p>
<p>This function provides a simple method of allowing user-defined widgets
to modify the command line argument under the cursor (or immediately to
the left of the cursor if the cursor is between arguments).</p>
<p>The argument can be an expression which when evaluated operates on the
shell parameter <code>ARG</code>, which will have been set to the command line
argument under the cursor. The expression should be suitably quoted to
prevent it being evaluated too early.</p>
<p>Alternatively, if the argument does not contain the string <code>ARG</code>, it is
assumed to be a shell function, to which the current command line
argument is passed as the only argument. The function should set the
variable <code>REPLY</code> to the new value for the command line argument. If the
function returns non-zero status, so does the calling function.</p>
<p>For example, a user-defined widget containing the following code
converts the characters in the argument under the cursor into all upper
case:</p>
<div class="example">
<pre><code class="language-example">modify-current-argument '${(U)ARG}'
</code></pre>
</div>
<p>The following strips any quoting from the current word (whether
backslashes or one of the styles of quotes), and replaces it with single
quoting throughout:</p>
<div class="example">
<pre><code class="language-example">modify-current-argument '${(qq)${(Q)ARG}}'
</code></pre>
</div>
<p>The following performs directory expansion on the command line argument
and replaces it by the absolute path:</p>
<div class="example">
<pre><code class="language-example">expand-dir() {
REPLY=${~1}
REPLY=${REPLY:a}
}
modify-current-argument expand-dir
</code></pre>
</div>
<p>In practice the function <code>expand-dir</code> would probably not be defined
within the widget where <code>modify-current-argument</code> is called.</p>
<hr />
<p><span id="Styles"></span></p>
<h3 id="2673-styles"><a class="header" href="#2673-styles">26.7.3 Styles</a></h3>
<p>The behavior of several of the above widgets can be controlled by the
use of the <code>zstyle</code> mechanism. In particular, widgets that interact with
the completion system pass along their context to any completions that
they invoke.</p>
<p><span id="index-break_002dkeys_002c-widget-style"></span></p>
<p><code>break-keys</code></p>
<p>This style is used by the <code>incremental-complete-word</code> widget. Its value
should be a pattern, and all keys matching this pattern will cause the
widget to stop incremental completion without the key having any further
effect. Like all styles used directly by <code>incremental-complete-word</code>,
this style is looked up using the context ‘<code>:incremental</code>’.</p>
<p><span id="index-completer_002c-completion-style-1"></span></p>
<p><code>completer</code></p>
<p>The <code>incremental-complete-word</code> and <code>insert-and-predict</code> widgets set up
their top-level context name before calling completion. This allows one
to define different sets of completer functions for normal completion
and for these widgets. For example, to use completion, approximation and
correction for normal completion, completion and correction for
incremental completion and only completion for prediction one could use:</p>
<div class="example">
<pre><code class="language-example">zstyle ':completion:*' completer \
_complete _correct _approximate
zstyle ':completion:incremental:*' completer \
_complete _correct
zstyle ':completion:predict:*' completer \
_complete
</code></pre>
</div>
<p>It is a good idea to restrict the completers used in prediction, because
they may be automatically invoked as you type. The <code>_list</code> and <code>_menu</code>
completers should never be used with prediction. The <code>_approximate</code>,
<code>_correct</code>, <code>_expand</code>, and <code>_match</code> completers may be used, but be aware
that they may change characters anywhere in the word behind the cursor,
so you need to watch carefully that the result is what you intended.</p>
<p><span id="index-cursor_002c-completion-style"></span></p>
<p><code>cursor</code></p>
<p>The <code>insert-and-predict</code> widget uses this style, in the context
‘<code>:predict</code>’, to decide where to place the cursor after completion has
been tried. Values are:</p>
<ul>
<li>
<p><code>complete</code><br />
The cursor is left where it was when completion finished, but only
if it is after a character equal to the one just inserted by the
user. If it is after another character, this value is the same as
‘<code>key</code>’.</p>
</li>
<li>
<p><code>key</code><br />
The cursor is left after the <code>n</code>th occurrence of the character just
inserted, where <code>n</code> is the number of times that character appeared
in the word before completion was attempted. In short, this has the
effect of leaving the cursor after the character just typed even if
the completion code found out that no other characters need to be
inserted at that position.</p>
</li>
</ul>
<p>Any other value for this style unconditionally leaves the cursor at the
position where the completion code left it.</p>
<p><span id="index-list_002c-widget-style"></span></p>
<p><code>list</code></p>
<p>When using the <code>incremental-complete-word</code> widget, this style says if
the matches should be listed on every key press (if they fit on the
screen). Use the context prefix ‘<code>:completion:incremental</code>’.</p>
<p>The <code>insert-and-predict</code> widget uses this style to decide if the
completion should be shown even if there is only one possible
completion. This is done if the value of this style is the string
<code>always</code>. In this case the context is ‘<code>:predict</code>’ (<em>not</em>
‘<code>:completion:predict</code>’).</p>
<p><span id="index-match_002c-widget-style"></span></p>
<p><code>match</code></p>
<p>This style is used by <code>smart-insert-last-word</code> to provide a pattern
(using full <code>EXTENDED_GLOB</code> syntax) that matches an interesting word.
The context is the name of the widget to which <code>smart-insert-last-word</code>
is bound (see above). The default behavior of <code>smart-insert-last-word</code>
is equivalent to:</p>
<div class="example">
<pre><code class="language-example">zstyle :insert-last-word match '*[[:alpha:]/\\]*'
</code></pre>
</div>
<p>However, you might want to include words that contain spaces:</p>
<div class="example">
<pre><code class="language-example">zstyle :insert-last-word match '*[[:alpha:][:space:]/\\]*'
</code></pre>
</div>
<p>Or include numbers as long as the word is at least two characters long:</p>
<div class="example">
<pre><code class="language-example">zstyle :insert-last-word match '*([[:digit:]]?|[[:alpha:]/\\])*'
</code></pre>
</div>
<p>The above example causes redirections like &quot;2&gt;&quot; to be included.</p>
<p><span id="index-prompt_002c-widget-style"></span></p>
<p><code>prompt</code></p>
<p>The <code>incremental-complete-word</code> widget shows the value of this style in
the status line during incremental completion. The string value may
contain any of the following substrings in the manner of the <code>PS1</code> and
other prompt parameters:</p>
<ul>
<li>
<p><code>%c</code><br />
Replaced by the name of the completer function that generated the
matches (without the leading underscore).</p>
</li>
<li>
<p><code>%l</code><br />
When the <code>list</code> style is set, replaced by ‘<code>...</code>’ if the list of
matches is too long to fit on the screen and with an empty string
otherwise. If the <code>list</code> style is ‘false’ or not set, ‘<code>%l</code>’ is
always removed.</p>
</li>
<li>
<p><code>%n</code><br />
Replaced by the number of matches generated.</p>
</li>
<li>
<p><code>%s</code><br />
Replaced by ‘<code>-no match-</code>’, ‘<code>-no prefix-</code>’, or an empty string if
there is no completion matching the word on the line, if the matches
have no common prefix different from the word on the line, or if
there is such a common prefix, respectively.</p>
</li>
<li>
<p><code>%u</code><br />
Replaced by the unambiguous part of all matches, if there is any,
and if it is different from the word on the line.</p>
</li>
</ul>
<p>Like ‘<code>break-keys</code>’, this uses the ‘<code>:incremental</code>’ context.</p>
<p><span id="index-stop_002dkeys_002c-widget-style"></span></p>
<p><code>stop-keys</code></p>
<p>This style is used by the <code>incremental-complete-word</code> widget. Its value
is treated similarly to the one for the <code>break-keys</code> style (and uses the
same context: ‘<code>:incremental</code>’). However, in this case all keys matching
the pattern given as its value will stop incremental completion and will
then execute their usual function.</p>
<p><span id="index-toggle_002c-widget-style"></span></p>
<p><code>toggle</code></p>
<p>This boolean style is used by <code>predict-on</code> and its related widgets in
the context ‘<code>:predict</code>’. If set to one of the standard ‘true’ values,
predictive typing is automatically toggled off in situations where it is
unlikely to be useful, such as when editing a multi-line buffer or after
moving into the middle of a line and then deleting a character. The
default is to leave prediction turned on until an explicit call to
<code>predict-off</code>.</p>
<p><span id="index-verbose_002c-widget-style"></span></p>
<p><code>verbose</code></p>
<p>This boolean style is used by <code>predict-on</code> and its related widgets in
the context ‘<code>:predict</code>’. If set to one of the standard ‘true’ values,
these widgets display a message below the prompt when the predictive
state is toggled. This is most useful in combination with the <code>toggle</code>
style. The default does not display these messages.</p>
<p><span id="index-widget_002c-widget-style"></span></p>
<p><code>widget</code></p>
<p>This style is similar to the <code>command</code> style: For widget functions that
use <code>zle</code> to call other widgets, this style can sometimes be used to
override the widget which is called. The context for this style is the
name of the calling widget (<em>not</em> the name of the calling function,
because one function may be bound to multiple widget names).</p>
<div class="example">
<pre><code class="language-example">zstyle :copy-earlier-word widget smart-insert-last-word
</code></pre>
</div>
<p>Check the documentation for the calling widget or function to determine
whether the <code>widget</code> style is used.</p>
<hr />
<p><span id="Exception-Handling"></span>
<span id="Exception-Handling-1"></span></p>
<h2 id="268-exception-handling"><a class="header" href="#268-exception-handling">26.8 Exception Handling</a></h2>
<p>Two functions are provided to enable zsh to provide exception handling
in a form that should be familiar from other languages.</p>
<p><span id="index-throw"></span></p>
<p><code>throw</code> <code>exception</code></p>
<p>The function <code>throw</code> throws the named <code>exception</code>. The name is an
arbitrary string and is only used by the <code>throw</code> and <code>catch</code> functions.
An exception is for the most part treated the same as a shell error,
i.e. an unhandled exception will cause the shell to abort all processing
in a function or script and to return to the top level in an interactive
shell.</p>
<p><code>catch</code> <code>exception-pattern</code></p>
<p>The function <code>catch</code> returns status zero if an exception was thrown and
the pattern <code>exception-pattern</code> matches its name. Otherwise it returns
status 1. <code>exception-pattern</code> is a standard shell pattern, respecting
the current setting of the <code>EXTENDED_GLOB</code> option. An alias <code>catch</code> is
also defined to prevent the argument to the function from matching
filenames, so patterns may be used unquoted. Note that as exceptions are
not fundamentally different from other shell errors it is possible to
catch shell errors by using an empty string as the exception name. The
shell variable <code>CAUGHT</code> is set by <code>catch</code> to the name of the exception
caught. It is possible to rethrow an exception by calling the <code>throw</code>
function again once an exception has been caught.
<span id="index-catch"></span></p>
<p>The functions are designed to be used together with the <code>always</code>
construct described in <a href="Shell-Grammar.html#Complex-Commands">Complex
Commands</a>. This is important as
only this construct provides the required support for exceptions. A
typical example is as follows.</p>
<div class="example">
<pre><code class="language-example">{
# &quot;try&quot; block
# ... nested code here calls &quot;throw MyExcept&quot;
} always {
# &quot;always&quot; block
if catch MyExcept; then
print &quot;Caught exception MyExcept&quot;
elif catch ''; then
print &quot;Caught a shell error. Propagating...&quot;
throw ''
fi
# Other exceptions are not handled but may be caught further
# up the call stack.
}
</code></pre>
</div>
<p>If all exceptions should be caught, the following idiom might be
preferable.</p>
<div class="example">
<pre><code class="language-example">{
# ... nested code here throws an exception
} always {
if catch *; then
case $CAUGHT in
(MyExcept)
print &quot;Caught my own exception&quot;
;;
(*)
print &quot;Caught some other exception&quot;
;;
esac
fi
}
</code></pre>
</div>
<p>In common with exception handling in other languages, the exception may
be thrown by code deeply nested inside the ‘try’ block. However, note
that it must be thrown inside the current shell, not in a subshell
forked for a pipeline, parenthesised current-shell construct, or some
form of command or process substitution.</p>
<p>The system internally uses the shell variable <code>EXCEPTION</code> to record the
name of the exception between throwing and catching. One drawback of
this scheme is that if the exception is not handled the variable
<code>EXCEPTION</code> remains set and may be incorrectly recognised as the name of
an exception if a shell error subsequently occurs. Adding <code>unset EXCEPTION</code> at the start of the outermost layer of any code that uses
exception handling will eliminate this problem.</p>
<hr />
<p><span id="MIME-Functions"></span> <span id="MIME-Functions-1"></span></p>
<h2 id="269-mime-functions"><a class="header" href="#269-mime-functions">26.9 MIME Functions</a></h2>
<p>Three functions are available to provide handling of files recognised by
extension, for example to dispatch a file <code>text.ps</code> when executed as a
command to an appropriate viewer.</p>
<p><span id="index-zsh_002dmime_002dsetup"></span>
<span id="index-zsh_002dmime_002dhandler"></span></p>
<p><code>zsh-mime-setup</code> [ <code>-fv</code> ] [ <code>-l</code> [ <code>suffix</code> ... ] ]</p>
<p><code>zsh-mime-handler</code> [ <code>-l</code> ] <code>command argument</code> ...</p>
<p>These two functions use the files <code>~/.mime.types</code> and <code>/etc/mime.types</code>,
which associate types and extensions, as well as <code>~/.mailcap</code> and
<code>/etc/mailcap</code> files, which associate types and the programs that handle
them. These are provided on many systems with the Multimedia Internet
Mail Extensions.</p>
<p>To enable the system, the function <code>zsh-mime-setup</code> should be autoloaded
and run. This allows files with extensions to be treated The function
<code>zsh-mime-handler</code> should not need to be called by the user.</p>
<p>The system works by setting up suffix aliases with ‘<code>alias -s</code>’. Suffix
aliases already installed by the user will not be overwritten.</p>
<p>For suffixes defined in lower case, upper case variants will also
automatically be handled (e.g. <code>PDF</code> is automatically handled if
handling for the suffix <code>pdf</code> is defined), but not vice versa.</p>
<p>Repeated calls to <code>zsh-mime-setup</code> do not override the existing is
given. Note, however, that this does not override existing suffix
aliases assigned to handlers other than <code>zsh-mime-handler</code>.</p>
<p>Calling <code>zsh-mime-setup</code> with the option <code>-l</code> lists the existing
mappings without altering them. Suffixes to list (which may contain
pattern characters that should be quoted from immediate interpretation
on the command line) may be given as additional arguments, otherwise all
suffixes are listed.</p>
<p>Calling <code>zsh-mime-setup</code> with the option <code>-v</code> causes verbose output to
be shown during the setup operation.</p>
<p>The system respects the <code>mailcap</code> flags <code>needsterminal</code> and
<code>copiousoutput</code>, see man page mailcap(4).</p>
<p>The functions use the following styles, which are defined with the
<code>zstyle</code> builtin command (<a href="Zsh-Modules.html#The-zsh_002fzutil-Module">The zsh/zutil
Module</a>). They should be
defined before <code>zsh-mime-setup</code> is run. The contexts used all start with
<code>:mime:</code>, with additional components in some cases. It is recommended
that a trailing <code>*</code> (suitably quoted) be appended to style patterns in
case the system is extended in future. Some examples are given below.</p>
<p>For files that have multiple suffixes, e.g. <code>.pdf.gz</code>, where the context
includes the suffix it will be looked up starting with the longest
possible suffix until a match for the style is found. For example, if
<code>.pdf.gz</code> produces a match for the handler, that will be used; otherwise
the handler for <code>.gz</code> will be used. Note that, owing to the way suffix
aliases work, it is always required that there be a handler for the
shortest possible suffix, so in this example <code>.pdf.gz</code> can only be
handled if <code>.gz</code> is also handled (though not necessarily in the same
way). Alternatively, if no handling for <code>.gz</code> on its own is needed,
simply adding the command</p>
<div class="example">
<pre><code class="language-example">alias -s gz=zsh-mime-handler
</code></pre>
</div>
<p>to the initialisation code is sufficient; <code>.gz</code> will not be handled on
its own, but may be in combination with other suffixes.</p>
<p><span id="index-current_002dshell_002c-MIME-style"></span></p>
<p><code>current-shell</code></p>
<p>If this boolean style is true, the mailcap handler for the context in
question is run using the <code>eval</code> builtin instead of by starting a new
<code>sh</code> process. This is more efficient, but may not work in the occasional
cases where the mailcap handler uses strict POSIX syntax.</p>
<p><span id="index-disown_002c-MIME-style"></span></p>
<p><code>disown</code></p>
<p>If this boolean style is true, mailcap handlers started in the
background will be disowned, i.e. not subject to job control within the
parent shell. Such handlers nearly always produce their own windows, so
the only likely harmful side effect of setting the style is that it
becomes harder to kill jobs from within the shell.</p>
<p><span id="index-execute_002das_002dis_002c-MIME-style"></span></p>
<p><code>execute-as-is</code></p>
<p>This style gives a list of patterns to be matched against files passed
for execution with a handler program. If the file matches the pattern,
the entire command line is executed in its current form, with no
handler. This is useful for files which might have suffixes is not set,
the pattern <code>*(*) *(/)</code> is used; handler, and the option <code>AUTO_CD</code> may
be used to change to directories that happen to have MIME suffixes.</p>
<p><span id="index-execute_002dnever_002c-MIME-style"></span></p>
<p><code>execute-never</code></p>
<p>This style is useful in combination with <code>execute-as-is</code>. It is set to
an array of patterns corresponding to full paths to files that the MIME
handler matches <code>execute-as-is</code>. This is useful for file from another
operating system. For example, if <code>/mnt/windows</code> is a Windows mount,
then</p>
<div class="example">
<pre><code class="language-example">zstyle ':mime:*' execute-never '/mnt/windows/*'
</code></pre>
</div>
<p>will ensure that any files found in that area will be executed as MIME
file name is matched against the pattern, regardless of how the file was
passed to the handler. The file is resolved to a full path using the
<code>:P</code> modifier described in <a href="Expansion.html#Modifiers">Modifiers</a>; this
means that symbolic links are resolved where possible, so that links
into other file systems behave in the correct fashion.</p>
<p><span id="index-file_002dpath_002c-MIME-style"></span></p>
<p><code>file-path</code></p>
<p>Used if the style <code>find-file-in-path</code> is true for the same context. Set
to an array of directories that are used for searching for the file to
be handled; the default is the command path given by the special
parameter <code>path</code>. The shell option <code>PATH_DIRS</code> is respected; if that is
set, the appropriate path will be searched even if the name of the file
to be handled as it appears on the command line contains a ‘<code>/</code>’. The
full context is <code>:mime:.``suffix``:</code>, as described for the style
<code>handler</code>.</p>
<p><span id="index-find_002dfile_002din_002dpath_002c-MIME-style"></span></p>
<p><code>find-file-in-path</code></p>
<p>If set, allows files whose names do not contain absolute paths to be
searched for in the command path or the path specified by the
<code>file-path</code> style. If the file is not found in the path, it is looked
for locally (whether or not the current directory is in the path); if it
is not found locally, the handler will abort unless the
<code>handle-nonexistent</code> style is set. Files found in the path are tested as
described for the style <code>execute-as-is</code>. The full context is
<code>:mime:.``suffix``:</code>, as described for the style <code>handler</code>.</p>
<p><span id="index-flags_002c-MIME-style"></span></p>
<p><code>flags</code></p>
<p>Defines flags to go with a handler; the context is as for the <code>handler</code>
style, and the format is as for the flags in <code>mailcap</code>.</p>
<p><span id="index-handle_002dnonexistent_002c-MIME-style"></span></p>
<p><code>handle-nonexistent</code></p>
<p>By default, arguments that don’t correspond to files are not passed to
the MIME handler in order to prevent it from intercepting commands found
in the path that happen to have suffixes. This style may be set to an
array of extended glob patterns for arguments that will be passed to the
handler even if they don’t exist. If it is not explicitly set it
defaults to <code>[[:alpha:]]#:/*</code> which allows URLs to be passed to the MIME
handler even though they don’t exist in that format in the file system.
The full context is <code>:mime:.``suffix``:</code>, as described for the style
<code>handler</code>.</p>
<p><span id="index-handler_002c-MIME-style"></span></p>
<p><code>handler</code></p>
<p>Specifies a handler for a suffix; the suffix is given by the context as
<code>:mime:.``suffix``:</code>, and the format of the handler is exactly that in
<code>mailcap</code>. Note in particular the ‘<code>.</code>’ and trailing colon to
distinguish this use of the context. This overrides any handler
specified by the <code>mailcap</code> files. If the handler requires a terminal,
the <code>flags</code> style should be set to include the word <code>needsterminal</code>, or
if the output is to be displayed through a pager (but not if the handler
is itself a pager), it should include <code>copiousoutput</code>.</p>
<p><span id="index-mailcap_002c-MIME-style"></span></p>
<p><code>mailcap</code></p>
<p>A list of files in the format of <code>~/.mailcap</code> and <code>/etc/mailcap</code> to be
read during setup, replacing the default list which consists of those
two files. The context is <code>:mime:</code>. A <code>+</code> in the list will be replaced
by the default files.</p>
<p><span id="index-mailcap_002dpriorities_002c-MIME-style"></span></p>
<p><code>mailcap-priorities</code></p>
<p>This style is used to resolve multiple mailcap entries for the same MIME
type. It consists of an array of the following elements, in descending
order of priority; later entries will be used if earlier entries are
unable to resolve the entries being compared. If none of the tests
resolve the entries, the first entry encountered is retained.</p>
<ul>
<li>
<p><code>files</code><br />
The order of files (entries in the <code>mailcap</code> style) read. Earlier
files are preferred. (Note this does not resolve entries in the same
file.)</p>
</li>
<li>
<p><code>priority</code><br />
The priority flag from the mailcap entry. The priority is an integer
from 0 to 9 with the default value being 5.</p>
</li>
<li>
<p><code>flags</code><br />
The test given by the <code>mailcap-prio-flags</code> option is used to resolve
entries.</p>
</li>
<li>
<p><code>place</code><br />
Later entries are preferred; as the entries are strictly ordered,
this test always succeeds.</p>
</li>
</ul>
<p>Note that as this style is handled during initialisation, the context is
always <code>:mime:</code>, with no discrimination by suffix.</p>
<p><span id="index-mailcap_002dprio_002dflags_002c-MIME-style"></span></p>
<p><code>mailcap-prio-flags</code></p>
<p>This style is used when the keyword <code>flags</code> is encountered in the list
of tests specified by the <code>mailcap-priorities</code> style. It should be set
to a list of patterns, each of which is tested against the flags
specified in the mailcap entry (in other words, the sets of assignments
found with some entries in the mailcap file). Earlier patterns in the
list are preferred to later ones, and matched patterns are preferred to
unmatched ones.</p>
<p><span id="index-mime_002dtypes_002c-MIME-style"></span></p>
<p><code>mime-types</code></p>
<p>A list of files in the format of <code>~/.mime.types</code> and <code>/etc/mime.types</code>
to be read during setup, replacing the default list which consists of
those two files. The context is <code>:mime:</code>. A <code>+</code> in the list will be
replaced by the default files.</p>
<p><span id="index-never_002dbackground_002c-MIME-style"></span></p>
<p><code>never-background</code></p>
<p>If this boolean style is set, the handler for the given context is
always run in the foreground, even if the flags provided in the mailcap
entry suggest it need not be (for example, it doesn’t require a
terminal).</p>
<p><span id="index-pager_002c-MIME-style"></span></p>
<p><code>pager</code></p>
<p>If set, will be used instead of <code>$PAGER</code> or <code>more</code> to handle suffixes
where the <code>copiousoutput</code> flag is set. The context is as for <code>handler</code>,
i.e. <code>:mime:.``suffix``:</code> for handling a file with the given <code>suffix</code>.</p>
<p>Examples:</p>
<div class="example">
<pre><code class="language-example">zstyle ':mime:*' mailcap ~/.mailcap /usr/local/etc/mailcap
zstyle ':mime:.txt:' handler less %s
zstyle ':mime:.txt:' flags needsterminal
</code></pre>
</div>
<p>When <code>zsh-mime-setup</code> is subsequently run, it will look for <code>mailcap</code>
entries in the two files given. Files of suffix <code>.txt</code> will be handled
by running ‘<code>less</code> <code>file.txt</code>’. The flag <code>needsterminal</code> is set to show
that this program must run attached to a terminal.</p>
<p>As there are several steps to dispatching a command, the following
should be checked if attempting to execute a file by extension <code>.``ext</code>
does not have the expected effect.</p>
<p>The command ‘<code>alias -s</code> <code>ext</code>’ should show ‘<code>ps=zsh-mime-handler</code>’. If
it shows something else, another suffix alias was already installed and
was not overwritten. If it shows nothing, no handler was installed: this
is most likely because no handler was found in the <code>.mime.types</code> and
<code>mailcap</code> combination for <code>.ext</code> files. In that case, appropriate
handling should be added to <code>~/.mime.types</code> and <code>mailcap</code>.</p>
<p>If the extension is handled by <code>zsh-mime-handler</code> but the file is not
opened correctly, either the handler defined for the type is incorrect,
or the flags associated with it are in appropriate. Running
<code>zsh-mime-setup -l</code> will show the handler and, if there are any, the
flags. A <code>%s</code> in the handler is replaced by the file (suitably quoted if
necessary). Check that the handler program listed lists and can be run
in the way shown. Also check that the flags <code>needsterminal</code> or
<code>copiousoutput</code> are set if the handler needs to be run under a terminal;
the second flag is used if the output should be sent to a pager.</p>
<div class="example">
<pre><code class="language-example">text/html; /usr/bin/lynx '%s'; needsterminal
</code></pre>
</div>
<p>Running ‘<code>zsh-mime-handler -l</code> <code>command line</code>’ prints the command line
that would be executed, simplified to remove the effect of any flags,
and quoted so that the output can be run as a complete zsh command line.
This is used by the completion system to decide how to complete after a
file handled by <code>zsh-mime-setup</code>.</p>
<p><span id="index-pick_002dweb_002dbrowser"></span></p>
<p><code>pick-web-browser</code></p>
<p>This function is separate from the two MIME functions described above
and can be assigned directly to a suffix:</p>
<div class="example">
<pre><code class="language-example">autoload -U pick-web-browser
alias -s html=pick-web-browser
</code></pre>
</div>
<p>It is provided as an intelligent front end to dispatch a web browser. It
may be run as either a function or a shell script. The status 255 is
returned if no browser could be started.</p>
<p>Various styles are available to customize the choice of browsers:</p>
<ul>
<li>
<p><code>browser-style</code><br />
The value of the style is an array giving preferences in decreasing
order for the type of browser to use. The values of elements may be</p>
<ul>
<li>
<p><code>running</code><br />
Use a GUI browser that is already running when an X Window
display is available. The browsers listed in the <code>x-browsers</code>
style are tried in order until one is found; if it is, the file
will be displayed in that browser, so the user may need to check
whether it has appeared. If no running browser is found, one is
not started. Browsers other than Firefox, Opera and Konqueror
are assumed to understand the Mozilla syntax for opening a URL
remotely.</p>
</li>
<li>
<p><code>x</code><br />
Start a new GUI browser when an X Window display is available.
Search for the availability of one of the browsers listed in the
<code>x-browsers</code> style and start the first one that is found. No
check is made for an already running browser.</p>
</li>
<li>
<p><code>tty</code><br />
Start a terminal-based browser. Search for the availability of
one of the browsers listed in the <code>tty-browsers</code> style and start
the first one that is found.</p>
</li>
</ul>
<p>If the style is not set the default <code>running x tty</code> is used.</p>
</li>
<li>
<p><code>x-browsers</code><br />
An array in decreasing order of preference of browsers to use when
running under the X Window System. The array consists of the command
name under which to start the browser. They are looked up in the
context <code>:mime:</code> (which may be extended in future, so appending
‘<code>*</code>’ is recommended). For example,</p>
<div class="example">
<pre><code class="language-example">zstyle ':mime:*' x-browsers opera konqueror firefox
</code></pre>
</div>
<p>specifies that <code>pick-web-browser</code> should first look for a running
instance of Opera, Konqueror or Firefox, in that order, and if it
fails to find any should attempt to start Opera. The default is
<code>firefox mozilla netscape opera konqueror</code>.</p>
</li>
<li>
<p><code>tty-browsers</code><br />
An array similar to <code>x-browsers</code>, except that it gives browsers to
use when no X Window display is available. The default is <code>elinks links lynx</code>.</p>
</li>
<li>
<p><code>command</code><br />
If it is set this style is used to pick the command used to open a
page for a browser. The context is <code>:mime:browser:new:$browser:</code> to
start a new browser or <code>:mime:browser:running:$browser:</code> to open a
URL in a browser already running on the current X display, where
<code>$browser</code> is the value matched in the <code>x-browsers</code> or
<code>tty-browsers</code> style. The escape sequence <code>%b</code> in the style’s value
will be replaced by the browser, while <code>%u</code> will be replaced by the
URL. If the style is not set, the default for all new instances is
equivalent to <code>%b %u</code> and the defaults for using running browsers
are equivalent to the values <code>kfmclient openURL %u</code> for Konqueror,
<code>firefox -new-tab %u</code> for Firefox, <code>opera -newpage %u</code> for Opera,
and <code>%b -remote &quot;openUrl(%u)&quot;</code> for all others.</p>
</li>
</ul>
<hr />
<p><span id="Mathematical-Functions"></span>
<span id="Mathematical-Functions-1"></span></p>
<h2 id="2610-mathematical-functions"><a class="header" href="#2610-mathematical-functions">26.10 Mathematical Functions</a></h2>
<p><span id="index-zcalc"></span></p>
<p><code>zcalc</code> [ <code>-erf</code> ] [ <code>expression</code> ... ]</p>
<p>A reasonably powerful calculator based on zsh’s arithmetic evaluation
facility. The syntax is similar to that of formulae in most programming
languages; see <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic
Evaluation</a> for
details.</p>
<p>Non-programmers should note that, as in many other programming
languages, expressions involving only integers (whether constants
without a ‘<code>.</code>’, variables containing such constants as strings, or
variables declared to be integers) are by default evaluated using
integer arithmetic, which is not how an ordinary desk calculator
operates. To force floating point operation, pass the option <code>-f</code>; see
further notes below.</p>
<p>If the file <code>~/.zcalcrc</code> exists it will be sourced inside the function
once it is set up and about to process the command line. This can be
used, for example, to set shell options; <code>emulate -L zsh</code> and <code>setopt extendedglob</code> are in effect at this point. Any failure to source the
file if it exists is treated as fatal. As with other initialisation
files, the directory <code>$ZDOTDIR</code> is used instead of <code>$HOME</code> if it is set.</p>
<p>The mathematical library <code>zsh/mathfunc</code> will be loaded if it is
available; see <a href="Zsh-Modules.html#The-zsh_002fmathfunc-Module">The zsh/mathfunc
Module</a>. The mathematical
functions correspond to the raw system libraries, so trigonometric
functions are evaluated using radians, and so on.</p>
<p>Each line typed is evaluated as an expression. The prompt shows a
number, which corresponds to a positional parameter where the result of
that calculation is stored. For example, the result of the calculation
on the line preceded by ‘<code>4&gt; </code>’ is available as <code>$4</code>. The last value
calculated is available as <code>ans</code>. Full command line editing, including
the history of previous calculations, is available; the history is saved
in the file <code>~/.zcalc_history</code>. To exit, enter a blank line or type
‘<code>:q</code>’ on its own (‘<code>q</code>’ is allowed for historical compatibility).</p>
<p>A line ending with a single backslash is treated in the same fashion as
it is in command line editing: the backslash is removed, the function
prompts for more input (the prompt is preceded by ‘<code>...</code>’ to indicate
this), and the lines are combined into one to get the final result. In
addition, if the input so far contains more open than close parentheses
<code>zcalc</code> will prompt for more input.</p>
<p>If arguments are given to <code>zcalc</code> on start up, they are used to prime
the first few positional parameters. A visual indication of this is
given when the calculator starts.</p>
<p>The constants <code>PI</code> (3.14159...) and <code>E</code> (2.71828...) are provided.
Parameter assignment is possible, but note that all parameters will be
put into the global namespace unless the <code>:local</code> special command is
used. The function creates local variables whose names start with <code>_</code>,
so users should avoid doing so. The variables <code>ans</code> (the last answer)
and <code>stack</code> (the stack in RPN mode) may be referred to directly; <code>stack</code>
is an array but elements of it are numeric. Various other special
variables are used locally with their standard meaning, for example
<code>compcontext</code>, <code>match</code>, <code>mbegin</code>, <code>mend</code>, <code>psvar</code>.</p>
<p>The output base can be initialised by passing the option ‘<code>-#``base</code>’,
for example ‘<code>zcalc -#16</code>’ (the ‘<code>#</code>’ may have to be quoted, depending
on the globbing options set).</p>
<p>If the option ‘<code>-e</code>’ is set, the function runs non-interactively: the
arguments are treated as expressions to be evaluated as if entered
interactively line by line.</p>
<p>If the option ‘<code>-f</code>’ is set, all numbers are treated as floating point,
hence for example the expression ‘<code>3/4</code>’ evaluates to 0.75 rather than</p>
<ol start="0">
<li>Options must appear in separate words.</li>
</ol>
<p>If the option ‘<code>-r</code>’ is set, RPN (Reverse Polish Notation) mode is
entered. This has various additional properties:</p>
<ul>
<li>
<p>Stack<br />
Evaluated values are maintained in a stack; this is contained in an
array named <code>stack</code> with the most recent value in <code>${stack[1]}</code>.</p>
</li>
<li>
<p>Operators and functions<br />
If the line entered matches an operator (<code>+</code>, <code>-</code>, <code>*</code>, <code>/</code>, <code>**</code>,
<code>^</code>, <code>|</code> or <code>&amp;</code>) or a function supplied by the <code>zsh/mathfunc</code>
library, the bottom element or elements of the stack are popped to
use as the argument or arguments. The higher elements of stack
(least recent) are used as earlier arguments. The result is then
pushed into <code>${stack[1]}</code>.</p>
</li>
<li>
<p>Expressions<br />
Other expressions are evaluated normally, printed, and added to the
stack as numeric values. The syntax within expressions on a single
line is normal shell arithmetic (not RPN).</p>
</li>
<li>
<p>Stack listing<br />
If an integer follows the option <code>-r</code> with no space, then on every
evaluation that many elements of the stack, where available, are
printed instead of just the most recent result. Hence, for example,
<code>zcalc -r4</code> shows <code>$stack[4]</code> to <code>$stack[1]</code> each time results are
printed.</p>
</li>
<li>
<p>Duplication: <code>=</code><br />
The pseudo-operator <code>=</code> causes the most recent element of the stack
to be duplicated onto the stack.</p>
</li>
<li>
<p><code>pop</code><br />
The pseudo-function <code>pop</code> causes the most recent element of the
stack to be popped. A ‘<code>&gt;</code>’ on its own has the same effect.</p>
</li>
<li>
<p><code>&gt;``ident</code><br />
The expression <code>&gt;</code> followed (with no space) by a shell identifier
causes the most recent element of the stack to be popped and
assigned to the variable with that name. The variable is local to
the <code>zcalc</code> function.</p>
</li>
<li>
<p><code>&lt;``ident</code><br />
The expression <code>&lt;</code> followed (with no space) by a shell identifier
causes the value of the variable with that name to be pushed onto
the stack. <code>ident</code> may be an integer, in which case the previous
result with that number (as shown before the <code>&gt;</code> in the standard
<code>zcalc</code> prompt) is put on the stack.</p>
</li>
<li>
<p>Exchange: <code>xy</code><br />
The pseudo-function <code>xy</code> causes the most recent two elements of the
stack to be exchanged. ‘<code>&lt;&gt;</code>’ has the same effect.</p>
</li>
</ul>
<p>The prompt is configurable via the parameter <code>ZCALCPROMPT</code>, which
undergoes standard prompt expansion. The index of the current entry is
stored locally in the first element of the array <code>psvar</code>, which can be
referred to in <code>ZCALCPROMPT</code> as ‘<code>%1v</code>’. The default prompt is ‘<code>%1v&gt;
</code>’.</p>
<p>The variable <code>ZCALC_ACTIVE</code> is set within the function and can be tested
by nested functions; it has the value <code>rpn</code> if RPN mode is active, else</p>
<ol>
<li></li>
</ol>
<p>A few special commands are available; these are introduced by a colon.
For backward compatibility, the colon may be omitted for certain
commands. Completion is available if <code>compinit</code> has been run.</p>
<p>The output precision may be specified within zcalc by special commands
familiar from many calculators.</p>
<ul>
<li>
<p><code>:norm</code><br />
The default output format. It corresponds to the printf <code>%g</code>
specification. Typically this shows six decimal digits.</p>
</li>
<li>
<p><code>:sci</code> <code>digits</code><br />
Scientific notation, corresponding to the printf <code>%g</code> output format
with the precision given by <code>digits</code>. This produces either fixed
point or exponential notation depending on the value output.</p>
</li>
<li>
<p><code>:fix</code> <code>digits</code><br />
Fixed point notation, corresponding to the printf <code>%f</code> output format
with the precision given by <code>digits</code>.</p>
</li>
<li>
<p><code>:eng</code> <code>digits</code><br />
Exponential notation, corresponding to the printf <code>%E</code> output format
with the precision given by <code>digits</code>.</p>
</li>
<li>
<p><code>:raw</code><br />
Raw output: this is the default form of the output from a math
evaluation. This may show more precision than the number actually
possesses.</p>
</li>
</ul>
<p>Other special commands:</p>
<ul>
<li>
<p><code>:!``line...</code><br />
Execute <code>line...</code> as a normal shell command line. Note that it is
executed in the context of the function, i.e. with local variables.
Space is optional after <code>:!</code>.</p>
</li>
<li>
<p><code>:local</code> <code>arg</code> ...<br />
Declare variables local to the function. Other variables may be
used, too, but they will be taken from or put into the global scope.</p>
</li>
<li>
<p><code>:function</code> <code>name</code> [ <code>body</code> ]<br />
Define a mathematical function or (with no <code>body</code>) delete it.
<code>:function</code> may be abbreviated to <code>:func</code> or simply <code>:f</code>. The <code>name</code>
may contain the same characters as a shell function name. The
function is defined using <code>zmathfuncdef</code>, see below.</p>
<p>Note that <code>zcalc</code> takes care of all quoting. Hence for example:</p>
<div class="example">
<pre><code class="language-example">:f cube $1 * $1 * $1
</code></pre>
</div>
<p>defines a function to cube the sole argument. Functions so defined,
or indeed any functions defined directly or indirectly using
<code>functions -M</code>, are available to execute by typing only the name on
the line in RPN mode; this pops the appropriate number of arguments
off the stack to pass to the function, i.e. 1 in the case of the
example <code>cube</code> function. If there are optional arguments only the
mandatory arguments are supplied by this means.</p>
</li>
<li>
<p><code>[#``base``]</code><br />
This is not a special command, rather part of normal arithmetic
syntax; however, when this form appears on a line by itself the
default output radix is set to <code>base</code>. Use, for example, ‘<code>[#16]</code>’
to display hexadecimal output preceded by an indication of the base,
or ‘<code>[##16]</code>’ just to display the raw number in the given base.
Bases themselves are always specified in decimal. ‘<code>[#]</code>’ restores
the normal output format. Note that setting an output base
suppresses floating point output; use ‘<code>[#]</code>’ to return to normal
operation.</p>
</li>
<li>
<p><code>$``var</code><br />
Print out the value of var literally; does not affect the
calculation. To use the value of var, omit the leading ‘<code>$</code>’.</p>
</li>
</ul>
<p>See the comments in the function for a few extra tips.</p>
<p><span id="index-max"></span> <span id="index-min"></span>
<span id="index-sum"></span> <span id="index-zmathfunc"></span></p>
<p><code>min(``arg``, ...)</code></p>
<p><code>max(``arg``, ...)</code></p>
<p><code>sum(``arg``, ...)</code></p>
<p><code>zmathfunc</code></p>
<p>The function <code>zmathfunc</code> defines the three mathematical functions <code>min</code>,
<code>max</code>, and <code>sum</code>. The functions <code>min</code> and <code>max</code> take one or more
arguments. The function <code>sum</code> takes zero or more arguments. Arguments
can be of different types (ints and floats).</p>
<p>Not to be confused with the <code>zsh/mathfunc</code> module, described in <a href="Zsh-Modules.html#The-zsh_002fmathfunc-Module">The
zsh/mathfunc Module</a>.</p>
<p><span id="index-zmathfuncdef"></span></p>
<p><code>zmathfuncdef</code> [ <code>mathfunc</code> [ <code>body</code> ] ]</p>
<p>A convenient front end to <code>functions -M</code>.</p>
<p>With two arguments, define a mathematical function named <code>mathfunc</code>
which can be used in any form of arithmetic evaluation. <code>body</code> is a
mathematical expression to implement the function. It may contain
references to position parameters <code>$1</code>, <code>$2</code>, ... to refer to mandatory
parameters and <code>${1:-``defvalue``}</code> ... to refer to optional parameters.
Note that the forms must be strictly adhered to for the function to
calculate the correct number of arguments. The implementation is held in
a shell function named <code>zsh_math_func_``mathfunc</code>; usually the user will
not need to refer to the shell function directly. Any existing function
of the same name is silently replaced.</p>
<p>With one argument, remove the mathematical function <code>mathfunc</code> as well
as the shell function implementation.</p>
<p>With no arguments, list all <code>mathfunc</code> functions in a form The functions
have not necessarily been defined by <code>zmathfuncdef</code>.</p>
<hr />
<p><span id="User-Configuration-Functions"></span>
<span id="User-Configuration-Functions-1"></span></p>
<h2 id="2611-user-configuration-functions"><a class="header" href="#2611-user-configuration-functions">26.11 User Configuration Functions</a></h2>
<p>The <code>zsh/newuser</code> module comes with a function to aid in configuring
shell options for new users. If the module is installed, this function
can also be run by hand. It is available even if the module’s default
behaviour, namely running the function for a new user logging in without
startup files, is inhibited.</p>
<ul>
<li>
<p><code>zsh-newuser-install</code> [ <code>-f</code> ]<br />
The function presents the user with various options for customizing
their initialization scripts. Currently only <code>~/.zshrc</code> is handled.
<code>$ZDOTDIR/.zshrc</code> is used instead if the parameter <code>ZDOTDIR</code> is set;
this provides a way for the user to configure a file without
altering an existing <code>.zshrc</code>.</p>
<p>By default the function exits immediately if it finds any of the
files <code>.zshenv</code>, <code>.zprofile</code>, <code>.zshrc</code>, or <code>.zlogin</code> in the
appropriate directory. The option <code>-f</code> is required in order to force
the function to continue. Note this may happen even if <code>.zshrc</code>
itself does not exist.</p>
<p>As currently configured, the function will exit immediately if the
user has root privileges; this behaviour cannot be overridden.</p>
<p>Once activated, the function’s behaviour is supposed to be
self-explanatory. Menus are present allowing the user to alter the
value of options and parameters. Suggestions for improvements are
always welcome.</p>
<p>When the script exits, the user is given the opportunity to save the
new file or not; changes are not irreversible until this point.
However, the script is careful to restrict changes to the file only
to a group marked by the lines ‘<code># Lines configured by zsh-newuser-install</code>’ and ‘<code># End of lines configured by zsh-newuser-install</code>’. In addition, the old version of <code>.zshrc</code> is
saved to a file with the suffix <code>.zni</code> appended.</p>
<p>If the function edits an existing <code>.zshrc</code>, it is up to the user to
ensure that the changes made will take effect. For example, if
control usually returns early from the existing <code>.zshrc</code> the lines
will not be executed; or a later initialization file may override
options or parameters, and so on. The function itself does not
attempt to detect any such conflicts.</p>
</li>
</ul>
<hr />
<p><span id="Other-Functions"></span> <span id="Other-Functions-1"></span></p>
<h2 id="2612-other-functions"><a class="header" href="#2612-other-functions">26.12 Other Functions</a></h2>
<p>There are a large number of helpful functions in the <code>Functions/Misc</code>
directory of the zsh distribution. Most are very simple and do not
require documentation here, but a few are worthy of special mention.</p>
<hr />
<p><span id="Descriptions"></span></p>
<h3 id="26121-descriptions"><a class="header" href="#26121-descriptions">26.12.1 Descriptions</a></h3>
<p><span id="index-colors"></span></p>
<p><code>colors</code></p>
<p>This function initializes several associative arrays to map color names
to (and from) the ANSI standard eight-color terminal codes. These are
used by the prompt theme system (<a href="User-Contributions.html#Prompt-Themes">Prompt Themes</a>). You
seldom should need to run <code>colors</code> more than once.</p>
<p>The eight base colors are: <code>black</code>, <code>red</code>, <code>green</code>, <code>yellow</code>, <code>blue</code>,
<code>magenta</code>, <code>cyan</code>, and <code>white</code>. Each of these has codes for foreground
and background. In addition there are seven intensity attributes:
<code>bold</code>, <code>faint</code>, <code>standout</code>, <code>underline</code>, <code>blink</code>, <code>reverse</code>, and
<code>conceal</code>. Finally, there are seven codes used to negate attributes:
<code>none</code> (reset all attributes to the defaults), <code>normal</code> (neither bold
nor faint), <code>no-standout</code>, <code>no-underline</code>, <code>no-blink</code>, <code>no-reverse</code>, and
<code>no-conceal</code>.</p>
<p>Some terminals do not support all combinations of colors and
intensities.</p>
<p>The associative arrays are:</p>
<ul>
<li>
<p><code>color</code><br />
<code>colour</code><br />
Map all the color names to their integer codes, and integer codes to
the color names. The eight base names map to the foreground color
codes, as do names prefixed with ‘<code>fg-</code>’, such as ‘<code>fg-red</code>’. Names
prefixed with ‘<code>bg-</code>’, such as ‘<code>bg-blue</code>’, refer to the background
codes. The reverse mapping from code to color yields base name for
foreground codes and the <code>bg-</code> form for backgrounds.</p>
<p>Although it is a misnomer to call them ‘colors’, these arrays also
map the other fourteen attributes from names to codes and codes to
names.</p>
</li>
<li>
<p><code>fg</code><br />
<code>fg_bold</code><br />
<code>fg_no_bold</code><br />
Map the eight basic color names to ANSI terminal escape sequences
that set the corresponding foreground text properties. The <code>fg</code>
sequences change the color without changing the eight intensity
attributes.</p>
</li>
<li>
<p><code>bg</code><br />
<code>bg_bold</code><br />
<code>bg_no_bold</code><br />
Map the eight basic color names to ANSI terminal escape sequences
that set the corresponding background properties. The <code>bg</code> sequences
change the color without changing the eight intensity attributes.</p>
</li>
</ul>
<p>In addition, the scalar parameters <code>reset_color</code> and <code>bold_color</code> are
set to the ANSI terminal escapes that turn off all attributes and turn
on bold intensity, respectively.</p>
<p><span id="index-fned"></span></p>
<p><code>fned</code> [ <code>-x</code> <code>num</code> ] <code>name</code></p>
<p>Same as <code>zed -f</code>. This function does not appear in the zsh distribution,
but can be created by linking <code>zed</code> to the name <code>fned</code> in some directory
in your <code>fpath</code>.</p>
<p><span id="index-is_002dat_002dleast"></span></p>
<p><code>is-at-least</code> <code>needed</code> [ <code>present</code> ]</p>
<p>Perform a greater-than-or-equal-to comparison of two strings having the
format of a zsh version number; that is, a string of numbers and text
with segments separated by dots or dashes. If the <code>present</code> string is
not provided, <code>$ZSH_VERSION</code> is used. Segments are paired left-to-right
in the two strings with leading non-number parts ignored. If one string
has fewer segments than the other, the missing segments are considered
zero.</p>
<p>This is useful in startup files to set options and other state that are
not available in all versions of zsh.</p>
<div class="example">
<pre><code class="language-example">is-at-least 3.1.6-15 &amp;&amp; setopt NO_GLOBAL_RCS
is-at-least 3.1.0 &amp;&amp; setopt HIST_REDUCE_BLANKS
is-at-least 2.6-17 || print &quot;You can't use is-at-least here.&quot;
</code></pre>
</div>
<p><span id="index-nslookup"></span></p>
<p><code>nslookup</code> [ <code>arg</code> ... ]</p>
<p>This wrapper function for the <code>nslookup</code> command requires the <code>zsh/zpty</code>
module (see <a href="Zsh-Modules.html#The-zsh_002fzpty-Module">The zsh/zpty
Module</a>). It behaves exactly
like the standard <code>nslookup</code> except that it provides customizable
prompts (including a right-side prompt) and completion of nslookup
commands, host names, etc. (if you use the function-based completion
system). Completion styles may be set with the context prefix
‘<code>:completion:nslookup</code>’.</p>
<p>See also the <code>pager</code>, <code>prompt</code> and <code>rprompt</code> styles below.</p>
<p><span id="index-regexp_002dreplace"></span></p>
<p><code>regexp-replace</code> <code>var</code> <code>regexp</code> <code>replace</code></p>
<p>Use regular expressions to perform a global search and replace operation
on a variable. POSIX extended regular expressions are used, unless the
option <code>RE_MATCH_PCRE</code> has been set, in which case Perl-compatible
regular expressions are used (this requires the shell to be linked
against the <code>pcre</code> library).</p>
<p><code>var</code> is the name of the variable containing the string to be matched.
The variable will be modified directly by the function. The variables
<code>MATCH</code>, <code>MBEGIN</code>, <code>MEND</code>, <code>match</code>, <code>mbegin</code>, <code>mend</code> should be avoided
as these are used by the regular expression code.</p>
<p><code>regexp</code> is the regular expression to match against the string.</p>
<p><code>replace</code> is the replacement text. This can contain parameter, command
and arithmetic expressions which will be replaced: in particular, a
reference to <code>$MATCH</code> will be replaced by the text matched by the
pattern.</p>
<p>The return status is 0 if at least one match was performed, else 1.</p>
<p><span id="index-run_002dhelp-1"></span></p>
<p><code>run-help</code> <code>cmd</code></p>
<p>This function is designed to be invoked by the <code>run-help</code> ZLE widget, in
place of the default alias. See ‘Accessing On-Line Help’
(<a href="User-Contributions.html#Utilities">Utilities</a>) for setup instructions.</p>
<p>In the discussion which follows, if <code>cmd</code> is a file system path, it is
first reduced to its rightmost component (the file name).</p>
<p>Help is first sought by looking for a file named <code>cmd</code> in the directory
named by the <code>HELPDIR</code> parameter. If no file is found, an assistant
function, alias, or command named <code>run-help-cmd</code> is sought. If found,
the assistant is executed with the rest of the current command line
(everything after the command name <code>cmd</code>) as its arguments. When neither
file nor assistant is found, the external command ‘<code>man</code> <code>cmd</code>’ is run.</p>
<p>An example assistant for the &quot;ssh&quot; command:</p>
<div class="example">
<pre><code class="language-example">run-help-ssh() {
emulate -LR zsh
local -a args
# Delete the &quot;-l username&quot; option
zparseopts -D -E -a args l:
# Delete other options, leaving: host command
args=(${@:#-*})
if [[ ${#args} -lt 2 ]]; then
man ssh
else
run-help $args[2]
fi
}
</code></pre>
</div>
<p>Several of these assistants are provided in the <code>Functions/Misc</code> your
search path, in order to be found and used by <code>run-help</code>.</p>
<p><span id="index-run_002dhelp_002dgit"></span>
<span id="index-run_002dhelp_002dip"></span>
<span id="index-run_002dhelp_002dopenssl"></span>
<span id="index-run_002dhelp_002dp4"></span>
<span id="index-run_002dhelp_002dsudo"></span>
<span id="index-run_002dhelp_002dsvk"></span>
<span id="index-run_002dhelp_002dsvn"></span></p>
<p>run-help-git</p>
<p>run-help-ip</p>
<p>run-help-openssl</p>
<p>run-help-p4</p>
<p>run-help-sudo</p>
<p>run-help-svk</p>
<p><code>run-help-svn</code></p>
<p>Assistant functions for the <code>git</code>, <code>ip</code>, <code>openssl</code>, <code>p4</code>, <code>sudo</code>, <code>svk</code>,
and <code>svn</code>, commands.</p>
<p><code>tetris</code></p>
<p>Zsh was once accused of not being as complete as Emacs, because it
lacked a Tetris game. This function was written to refute this vicious
slander.</p>
<p>This function must be used as a ZLE widget:</p>
<div class="example">
<pre><code class="language-example">autoload -U tetris
zle -N tetris
bindkey keys tetris
</code></pre>
</div>
<p>To start a game, execute the widget by typing the <code>keys</code>. Whatever
command line you were editing disappears temporarily, and your keymap is
also temporarily replaced by the Tetris control keys. The previous
editor state is restored when you quit the game (by pressing ‘<code>q</code>’) or
when you lose.</p>
<p>If you quit in the middle of a game, the next invocation of the <code>tetris</code>
widget will continue where you left off. If you lost, it will start a
new game.</p>
<p><code>tetriscurses</code></p>
<p>This is a port of the above to zcurses. The input handling is improved a
bit so that moving a block sideways doesn’t automatically advance a
timestep, and the graphics use unicode block graphics.</p>
<p>This version does not save the game state between invocations, and is
not invoked as a widget, but rather as:</p>
<div class="example">
<pre><code class="language-example">autoload -U tetriscurses
tetriscurses
</code></pre>
</div>
<p><span id="index-zargs"></span></p>
<p><code>zargs</code> [ <code>option</code> ... <code>-``-</code> ] [ <code>input</code> ... ] [ <code>-``-</code> <code>command</code>
[ <code>arg</code> ... ] ]</p>
<p>This function has a similar purpose to GNU xargs. Instead of reading
lines of arguments from the standard input, it takes them from the
command line. This is useful because zsh, especially with recursive glob
operators, often can construct a command line for a shell function that
is longer than can be accepted by an external command.</p>
<p>The <code>option</code> list represents options of the <code>zargs</code> command itself,
which are the same as those of <code>xargs</code>. The <code>input</code> list is the
collection of strings (often file names) that become the arguments of
the <code>command</code>, analogous to the standard input of <code>xargs</code>. Finally, the
<code>arg</code> list consists of those arguments (usually options) that are passed
to the <code>command</code> each time it runs. The <code>arg</code> list precedes the elements
from the <code>input</code> list in each run. If no <code>command</code> is provided, then no
<code>arg</code> list may be provided, and in that event the default command is
‘<code>print</code>’ with arguments ‘<code>-r -``-</code>’.</p>
<p>For example, to get a long <code>ls</code> listing of all non-hidden plain files in
the current directory or its subdirectories:</p>
<div class="example">
<pre><code class="language-example">autoload -U zargs
zargs -- **/*(.) -- ls -ld --
</code></pre>
</div>
<p>The first and third occurrences of ‘<code>-``-</code>’ are used to mark the end of
options for <code>zargs</code> and <code>ls</code> respectively to guard against filenames
starting with ‘<code>-</code>’, while the second is used to separate the list of
files from the command to run (‘<code>ls -ld –</code>’).</p>
<p>The first ‘<code>-``-</code>’ would also be needed if there was a chance the list
might be empty as in:</p>
<div class="example">
<pre><code class="language-example">zargs -r -- ./*.back(#qN) -- rm -f
</code></pre>
</div>
<p>In the event that the string ‘<code>-``-</code>’ is or may be an <code>input</code>, the <code>-e</code>
option may be used to change the end-of-inputs marker. Note that this
does <em>not</em> change the end-of-options marker. For example, to use ‘<code>..</code>’
as the marker:</p>
<div class="example">
<pre><code class="language-example">zargs -e.. -- **/*(.) .. ls -ld --
</code></pre>
</div>
<p>This is a good choice in that example because no plain file can be named
‘<code>..</code>’, but the best end-marker depends on the circumstances.</p>
<p>The options <code>-i</code>, <code>-I</code>, <code>-l</code>, <code>-L</code>, and <code>-n</code> differ slightly from their
usage in <code>xargs</code>. There are no input lines for <code>zargs</code> to count, so <code>-l</code>
and <code>-L</code> count through the <code>input</code> list, and <code>-n</code> counts the number of
arguments passed to each execution of <code>command</code>, <em>including</em> any <code>arg</code>
list. Also, any time <code>-i</code> or <code>-I</code> is used, each <code>input</code> is processed
separately as if by ‘<code>-L</code> <code>1</code>’.</p>
<p>For details of the other <code>zargs</code> options, see man page xargs(1) (but
note the difference in function between <code>zargs</code> and <code>xargs</code>) or run
<code>zargs</code> with the <code>-``-help</code> option.</p>
<p><span id="index-zed"></span></p>
<p><code>zed</code> [ <code>-f</code> [ <code>-x</code> <code>num</code> ] ] <code>name</code></p>
<p><code>zed -b</code></p>
<p>This function uses the ZLE editor to edit a file or function.</p>
<p>Only one <code>name</code> argument is allowed. If the <code>-f</code> option is given, the
name is taken to be that of a function; if the function is marked for
autoloading, <code>zed</code> searches for it in the <code>fpath</code> and loads it. Note
that functions edited this way are installed into the current shell, but
<em>not</em> written back to the autoload file. In this case the <code>-x</code> option
specifies that leading tabs indenting the function according to syntax
should be converted into the given number of spaces; ‘<code>-x 2</code>’ is
consistent with the layout of functions distributed with the shell.</p>
<p>Without <code>-f</code>, <code>name</code> is the path name of the file to edit, which need
not exist; it is created on write, if necessary.</p>
<p>While editing, the function sets the main keymap to <code>zed</code> and the vi
command keymap to <code>zed-vicmd</code>. These will be copied from the existing
<code>main</code> and <code>vicmd</code> keymaps if they do not exist the first time <code>zed</code> is
run. They can be used to provide special key bindings used only in zed.</p>
<p>If it creates the keymap, <code>zed</code> rebinds the return key to insert a line
break and ‘<code>^X^W</code>’ to accept the edit in the <code>zed</code> keymap, and binds
‘<code>ZZ</code>’ to accept the edit in the <code>zed-vicmd</code> keymap.</p>
<p>The bindings alone can be installed by running ‘<code>zed -b</code>’. This is this
will overwrite the existing <code>zed</code> and <code>zed-vicmd</code> keymaps.</p>
<p>Completion is available, and styles may be set with the context prefix
‘<code>:completion:zed</code>’.</p>
<p>A zle widget <code>zed-set-file-name</code> is available. This can be called by
name from within zed using ‘<code>\ex zed-set-file-name</code>’ (note, however,
that because of zed’s rebindings you will have to type <code>^j</code> at the end
instead of the return key), or can be bound to a key in either of the
<code>zed</code> or <code>zed-vicmd</code> keymaps after ‘<code>zed -b</code>’ has been run. When the
widget is called, it prompts for a new name for the file being edited.
When zed exits the file will be written under that name and the original
file will be left alone. The widget has no effect with ‘<code>zed -f</code>’.</p>
<p>While <code>zed-set-file-name</code> is running, zed uses the keymap
<code>zed-normal-keymap</code>, which is linked from the main keymap in effect at
the time zed initialised its bindings. (This is to make the return key
operate normally.) The result is that if the main keymap has been
changed, the widget won’t notice. This is not a concern for most users.</p>
<p><span id="index-zcp"></span> <span id="index-zln"></span></p>
<p><code>zcp</code> [ <code>-finqQvwW</code> ] <code>srcpat</code> <code>dest</code></p>
<p><code>zln</code> [ <code>-finqQsvwW</code> ] <code>srcpat</code> <code>dest</code></p>
<p>Same as <code>zmv -C</code> and <code>zmv -L</code>, respectively. These functions do not
appear in the zsh distribution, but can be created by linking <code>zmv</code> to
the names <code>zcp</code> and <code>zln</code> in some directory in your <code>fpath</code>.</p>
<p><code>zkbd</code></p>
<p>See ‘Keyboard Definition’ (<a href="User-Contributions.html#Utilities">Utilities</a>).</p>
<p><span id="index-zmv"></span></p>
<p><code>zmv</code> [ <code>-finqQsvwW</code> ] [ <code>-C</code> | <code>-L</code> | <code>-M</code> | -{<code>p</code>|<code>P</code>} <code>program</code> ]
[ <code>-o</code> <code>optstring</code> ]</p>
<p><code>    ``srcpat</code> <code>dest</code></p>
<p>Move (usually, rename) files matching the pattern <code>srcpat</code> to
corresponding files having names of the form given by <code>dest</code>, where
<code>srcpat</code> contains parentheses surrounding patterns which will be
replaced in turn by <code>$1</code>, <code>$2</code>, ... in <code>dest</code>. For example,</p>
<div class="example">
<pre><code class="language-example">zmv '(*).lis' '$1.txt'
</code></pre>
</div>
<p>renames ‘<code>foo.lis</code>’ to ‘<code>foo.txt</code>’, ‘<code>my.old.stuff.lis</code>’ to
‘<code>my.old.stuff.txt</code>’, and so on.</p>
<p>The pattern is always treated as an <code>EXTENDED_GLOB</code> pattern. Any file
whose name is not changed by the substitution is simply ignored. Any
error (a substitution resulted in an empty string, two substitutions
gave the same result, the destination was an existing regular file and
<code>-f</code> was not given) causes the entire function to abort without doing
anything.</p>
<p>In addition to pattern replacement, the variable <code>$f</code> can be referrred
to in the second (replacement) argument. This makes it possible to use
variable substitution to alter the argument; see examples below.</p>
<p>Options:</p>
<ul>
<li>
<p><code>-f</code><br />
Force overwriting of destination files. Not currently passed down to
the <code>mv</code>/<code>cp</code>/<code>ln</code> command due to vagaries of implementations (but
you can use <code>-o-f</code> to do that).</p>
</li>
<li>
<p><code>-i</code><br />
Interactive: show each line to be executed and ask the user whether
to execute it. ‘<code>Y</code>’ or ‘<code>y</code>’ will execute it, anything else will
skip it. Note that you just need to type one character.</p>
</li>
<li>
<p><code>-n</code><br />
No execution: print what would happen, but don’t do it.</p>
</li>
<li>
<p><code>-q</code><br />
Turn bare glob qualifiers off: now assumed by default, so this has
no effect.</p>
</li>
<li>
<p><code>-Q</code><br />
Force bare glob qualifiers on. Don’t turn this on unless you are
actually using glob qualifiers in a pattern.</p>
</li>
<li>
<p><code>-s</code><br />
Symbolic, passed down to <code>ln</code>; only works with <code>-L</code>.</p>
</li>
<li>
<p><code>-v</code><br />
Verbose: print each command as it’s being executed.</p>
</li>
<li>
<p><code>-w</code><br />
Pick out wildcard parts of the pattern, as described above, and
implicitly add parentheses for referring to them.</p>
</li>
<li>
<p><code>-W</code><br />
Just like <code>-w</code>, with the addition of turning wildcards in the
replacement pattern into sequential <code>${1}</code> .. <code>${N}</code> references.</p>
</li>
<li>
<p><code>-C</code><br />
<code>-L</code><br />
<code>-M</code><br />
Force <code>cp</code>, <code>ln</code> or <code>mv</code>, respectively, regardless of the name of
the function.</p>
</li>
<li>
<p><code>-p</code> <code>program</code><br />
Call <code>program</code> instead of <code>cp</code>, <code>ln</code> or <code>mv</code>. Whatever it does, it
should at least understand the form</p>
<div class="example">
<pre><code class="language-example">program -- oldname newname
</code></pre>
</div>
<p>where <code>oldname</code> and <code>newname</code> are filenames generated by <code>zmv</code>.
<code>program</code> will be split into words, so might be e.g. the name of an
archive tool plus a copy or rename subcommand.</p>
</li>
<li>
<p><code>-P</code> <code>program</code><br />
As <code>-p</code> <code>program</code>, except that <code>program</code> does not accept a following
<code>-``-</code> to indicate the end of options. In this case filenames must
already be in a sane form for the program in question.</p>
</li>
<li>
<p><code>-o</code> <code>optstring</code><br />
The <code>optstring</code> is split into words and passed down verbatim to the
<code>cp</code>, <code>ln</code> or <code>mv</code> command called to perform the work. It should
probably begin with a ‘<code>-</code>’.</p>
</li>
</ul>
<p>Further examples:</p>
<div class="example">
<pre><code class="language-example">zmv -v '(* *)' '${1// /_}'
</code></pre>
</div>
<p>For any file in the current directory with at least one space in the
name, replace every space by an underscore and display the commands
executed.</p>
<div class="example">
<pre><code class="language-example">zmv -v '* *' '${f// /_}'
</code></pre>
</div>
<p>This does exactly the same by referring to the file name stored in <code>$f</code>.</p>
<p>For more complete examples and other implementation details, see the
<code>zmv</code> source file, usually located in one of the directories named in
your <code>fpath</code>, or in <code>Functions/Misc/zmv</code> in the zsh distribution.</p>
<p><code>zrecompile</code></p>
<p>See ‘Recompiling Functions’ (<a href="User-Contributions.html#Utilities">Utilities</a>).</p>
<p><span id="index-zstyle_002b"></span></p>
<p><code>zstyle+</code> <code>context</code> <code>style</code> <code>value</code> [ <code>+</code> <code>subcontext</code> <code>style</code> <code>value</code>
... ]</p>
<p>This makes defining styles a bit simpler by using a single ‘<code>+</code>’ as a
special token that allows you to append a context name to the previously
used context name. Like this:</p>
<div class="example">
<pre><code class="language-example">zstyle+ ':foo:bar' style1 value1 \
+':baz' style2 value2 \
+':frob' style3 value3
</code></pre>
</div>
<p>This defines <code>style1</code> with <code>value1</code> for the context <code>:foo:bar</code> as usual,
but it also defines <code>style2</code> with <code>value2</code> for the context
<code>:foo:bar:baz</code> and <code>style3</code> with <code>value3</code> for <code>:foo:bar:frob</code>. Any
<code>subcontext</code> may be the empty string to re-use the first context
unchanged.</p>
<hr />
<p><span id="Styles-2"></span></p>
<h3 id="26122-styles"><a class="header" href="#26122-styles">26.12.2 Styles</a></h3>
<p><span id="index-insert_002dtab_002c-completion-style-1"></span></p>
<p><code>insert-tab</code></p>
<p>The <code>zed</code> function <em>sets</em> this style in context ‘<code>:completion:zed:*</code>’ to
turn off completion when <code>TAB</code> is typed at the beginning of a line. You
may override this by setting your own value for this context and style.</p>
<p><span id="index-pager_002c-nslookup-style"></span></p>
<p><code>pager</code></p>
<p>The <code>nslookup</code> function looks up this style in the context ‘<code>:nslookup</code>’
to determine the program used to display output that does not fit on a
single screen.</p>
<p><span id="index-prompt_002c-nslookup-style"></span>
<span id="index-rprompt_002c-nslookup-style"></span></p>
<p><code>prompt</code></p>
<p><code>rprompt</code></p>
<p>The <code>nslookup</code> function looks up this style in the context ‘<code>:nslookup</code>’
to set the prompt and the right-side prompt, respectively. The usual
expansions for the <code>PS1</code> and <code>RPS1</code> parameters may be used (see <a href="Prompt-Expansion.html#Prompt-Expansion">Prompt
Expansion</a>).</p>
<hr />
<p>This document was generated on <em>February 15, 2020</em> using
<a href="http://www.nongnu.org/texi2html/"><em>texi2html 5.0</em></a>.<br />
Zsh version 5.8, released on February 14, 2020.</p>
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