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1 The Z Shell Manual
This document has been produced from the texinfo file zsh.texi
,
included in the Doc
sub-directory of the Zsh distribution.
1.1 Producing documentation from zsh.texi
The texinfo source may be converted into several formats:
-
The Info manual
The Info format allows searching for topics, commands, functions, etc. from the many Indices. The command ‘makeinfo zsh.texi
’ is used to produce the Info documentation. -
The printed manual
The command ‘texi2dvi zsh.texi
’ will outputzsh.dvi
which can then be processed with dvips and optionally gs (Ghostscript) to produce a nicely formatted printed manual. -
The HTML manual
An HTML version of this manual is available at the Zsh web site via:http://zsh.sourceforge.net/Doc/
.(The HTML version is produced with texi2html, which may be obtained from
http://www.nongnu.org/texi2html/
. The command is ‘texi2html –output . –ifinfo –split=chapter –node-files zsh.texi
’. If necessary, upgrade to version 1.78 of texi2html.)
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
zsh-doc.tar.gz
. (See Availability
for a list of sites.)
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Zsh version 5.8, released on February 14, 2020.
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2 Introduction
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 Compatibility.
Zsh has command line editing, builtin spelling correction, programmable command completion, shell functions (with autoloading), a history mechanism, and a host of other features.
2.1 Author
Zsh was originally written by Paul Falstad <pf@zsh.org>
. Zsh is now
maintained by the members of the zsh-workers mailing list
<zsh-workers@zsh.org>
. The development is currently coordinated by
Peter Stephenson <pws@zsh.org>
. The coordinator can be contacted at
<coordinator@zsh.org>
, but matters relating to the code should
generally go to the mailing list.
2.2 Availability
Zsh is available from the following HTTP and anonymous FTP site.
ftp://ftp.zsh.org/pub/
https://www.zsh.org/pub/
)
The up-to-date source code is available via Git from Sourceforge. See
https://sourceforge.net/projects/zsh/
for details. A summary of
instructions for the archive can be found at
http://zsh.sourceforge.net/
.
2.3 Mailing Lists
Zsh has 3 mailing lists:
-
<zsh-announce@zsh.org>
Announcements about releases, major changes in the shell and the monthly posting of the Zsh FAQ. (moderated) -
<zsh-users@zsh.org>
User discussions. -
<zsh-workers@zsh.org>
Hacking, development, bug reports and patches.
To subscribe or unsubscribe, send mail to the associated administrative address for the mailing list.
<zsh-announce-subscribe@zsh.org>
<zsh-users-subscribe@zsh.org>
<zsh-workers-subscribe@zsh.org>
<zsh-announce-unsubscribe@zsh.org>
<zsh-users-unsubscribe@zsh.org>
<zsh-workers-unsubscribe@zsh.org>
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.
If you have problems subscribing/unsubscribing to any of the mailing
lists, send mail to <listmaster@zsh.org>
. The mailing lists are
maintained by Karsten Thygesen <karthy@kom.auc.dk>
.
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 <gcw@zsh.org>
, available at
https://www.zsh.org/mla/
.
2.4 The Zsh FAQ
Zsh has a list of Frequently Asked Questions (FAQ), maintained by Peter
Stephenson <pws@zsh.org>
. 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
http://www.zsh.org/FAQ/
. The contact address for FAQ-related matters
is <faqmaster@zsh.org>
.
2.5 The Zsh Web Page
Zsh has a web page which is located at https://www.zsh.org/
. This is
maintained by Karsten Thygesen <karthy@zsh.org>
, of SunSITE Denmark.
The contact address for web-related matters is <webmaster@zsh.org>
.
2.6 The Zsh Userguide
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 http://zsh.sourceforge.net/Guide/
. At the time of writing,
chapters dealing with startup files and their contents and the new
completion system were essentially complete.
2.7 See Also
man page sh(1), man page csh(1), man page tcsh(1), man page rc(1), man page bash(1), man page ksh(1)
IEEE Standard for information Technology - Part 2: Shell and Utilities, IEEE Inc, 1993, ISBN 1-55937-255-9.
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3 Roadmap
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.
3.1 When the shell starts
When it starts, the shell reads commands from various files. These can be created or edited to customize the shell. See Files.
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 zsh/newuser
module. The function is designed to be self-explanatory. You can run it
by hand with ‘autoload -Uz zsh-newuser-install; zsh-newuser-install -f
’. See also User Configuration
Functions.
3.2 Interactive Use
Interaction with the shell uses the builtin Zsh Line Editor, ZLE. This is described in detail in Zsh Line Editor.
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 bindkey -e
.
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) HISTFILE
,
HISTSIZE
and SAVEHIST
in Parameters Used By The
Shell. 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.
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, http://www.zsh.org/FAQ/
. Note in particular that for combining
characters to be handled the option COMBINING_CHARS
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 LANG
(to affect all aspects of the shell’s operation) or LC_CTYPE
(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 ISO-8859-1
or ISO-8859-15
. See
the description of LC_CTYPE
in
Parameters.
3.2.1 Completion
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 ~/.abook/addressbook
; 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.
Zsh has two completion systems, an old, so called compctl
completion
(named after the builtin command that serves as its complete and only
user interface), and a new one, referred to as compsys
, 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.
The completion system must be enabled explicitly when the shell starts. For more information see Completion System.
3.2.2 Extending the line editor
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:
-
insert-composed-char
composing characters not found on the keyboard -
match-words-by-style
configuring what the line editor considers a word when moving or deleting by word -
history-beginning-search-backward-end
, etc.
alternative ways of searching the shell history -
replace-string
,replace-pattern
functions for replacing strings or patterns globally in the command line -
edit-command-line
edit the command line with an external editor.
See ZLE Functions for descriptions of these.
3.3 Options
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 Options.
3.4 Pattern Matching
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 Filename Generation.
Of particular interest are the following patterns that are not commonly supported by other systems of pattern matching:
-
**
for matching over multiple directories -
|
for matching either of two alternatives -
~
,^
the ability to exclude patterns from matching when theEXTENDED_GLOB
option is set -
(``...``)
glob qualifiers, included in parentheses at the end of the pattern, which select files by type (such as directories) or attribute (such as size).
3.5 General Comments on Syntax
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 Shell Grammar.
One commonly encountered difference is that variables substituted onto
the command line are not split into words. See the description of the
shell option SH_WORD_SPLIT
in Parameter
Expansion. In zsh, you can either
explicitly request the splitting (e.g. ${=foo}
) or use an array when
you want a variable to expand to more than one word. See Array
Parameters.
3.6 Programming
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 Functions. 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.
A few general functions, other than those for the line editor described above, are provided with the shell and are described in User Contributions. Features include:
-
promptinit
a prompt theme system for changing prompts easily, see Prompt Themes -
zsh-mime-setup
a MIME-handling system which dispatches commands according to the suffix of a file as done by graphical file managers -
zcalc
a calculator -
zargs
a version ofxargs
that makes thefind
command redundant -
zmv
a command for renaming files by means of shell patterns.
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4 Invocation
4.1 Invocation
The following flags are interpreted by the shell when invoked to determine where the shell will read commands from:
-
-c
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$0
, rather than being used as a positional parameter. -
-i
Force shell to be interactive. It is still possible to specify a script to execute. -
-s
Force shell to read commands from the standard input. If the-s
flag is not present and an argument is given, the first argument is taken to be the pathname of a script to execute.
If there are any remaining arguments after option processing, and
neither of the options -c
or -s
was supplied, the first argument is
taken as the file name of a script containing shell commands to be
executed. If the option PATH_SCRIPT
is set, and the file name does not
contain a directory path (i.e. there is no ‘/
’ in the name), first the
current directory and then the command path given by the variable PATH
are searched for the script. If the option is not set or the file name
contains a ‘/
’ it is used directly.
After the first one or two arguments have been appropriated as described above, the remaining arguments are assigned to the positional parameters.
For further options, which are common to invocation and the set
builtin, see Options.
The long option ‘-``-emulate
’ followed (in a separate word) by an
emulation mode may be passed to the shell. The emulation modes are those
described for the emulate
builtin, see Shell Builtin
Commands. The
‘-``-emulate
’ 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 emulate
command within the shell: for example,
variables that conflict with POSIX usage such as path
are not defined
within the shell.
Options may be specified by name using the -o
option. -o
acts like a
single-letter option, but takes a following string as the option name.
For example,
zsh -x -o shwordsplit scr
runs the script scr
, setting the XTRACE
option by the corresponding
letter ‘-x
’ and the SH_WORD_SPLIT
option by name. Options may be
turned off by name by using +o
instead of -o
. -o
can be stacked
up with preceding single-letter options, so for example ‘-xo shwordsplit
’ or ‘-xoshwordsplit
’ is equivalent to ‘-x -o shwordsplit
’.
Options may also be specified by name in GNU long option style,
‘-``-``option-name
’. When this is done, ‘-
’ characters in the
option name are permitted: they are translated into ‘_
’, and thus
ignored. So, for example, ‘zsh -``-sh-word-split
’ invokes zsh with the
SH_WORD_SPLIT
option turned on. Like other option syntaxes, options
can be turned off by replacing the initial ‘-
’ with a ‘+
’; thus
‘+-sh-word-split
’ is equivalent to ‘-``-no-sh-word-split
’. Unlike
other option syntaxes, GNU-style long options cannot be stacked with any
other options, so for example ‘-x-shwordsplit
’ is an error, rather
than being treated like ‘-x -``-shwordsplit
’.
The special GNU-style option ‘-``-version
’ is handled; it sends to
standard output the shell’s version information, then exits
successfully. ‘-``-help
’ is also handled; it sends to standard output
a list of options that can be used when invoking the shell, then exits
successfully.
Option processing may be finished, allowing following arguments that
start with ‘-
’ or ‘+
’ to be treated as normal arguments, in two
ways. Firstly, a lone ‘-
’ (or ‘+
’) as an argument by itself ends
option processing. Secondly, a special option ‘-``-
’ (or ‘+-
’),
which may be specified on its own (which is the standard POSIX usage) or
may be stacked with preceding options (so ‘-x-
’ is equivalent to ‘-x -``-
’). Options are not permitted to be stacked after ‘-``-
’ (so
‘-x-f
’ is an error), but note the GNU-style option form discussed
above, where ‘-``-shwordsplit
’ is permitted and does not end option
processing.
Except when the sh/ksh emulation single-letter options are in effect,
the option ‘-b
’ (or ‘+b
’) ends option processing. ‘-b
’ is like
‘-``-
’, except that further single-letter options can be stacked
after the ‘-b
’ and will take effect as normal.
4.2 Compatibility
Zsh tries to emulate sh or ksh when it is invoked as sh
or ksh
respectively; more precisely, it looks at the first letter of the name
by which it was invoked, excluding any initial ‘r
’ (assumed to stand
for ‘restricted’), and if that is ‘b
’, ‘s
’ or ‘k
’ it will emulate
sh or ksh. Furthermore, if invoked as su
(which happens on certain
systems when the shell is executed by the su
command), the shell will
try to find an alternative name from the SHELL
environment variable
and perform emulation based on that.
In sh and ksh compatibility modes the following parameters are not
special and not initialized by the shell: ARGC
, argv
, cdpath
,
fignore
, fpath
, HISTCHARS
, mailpath
, MANPATH
, manpath
,
path
, prompt
, PROMPT
, PROMPT2
, PROMPT3
, PROMPT4
, psvar
,
status
, watch
.
The usual zsh startup/shutdown scripts are not executed. Login shells
source /etc/profile
followed by $HOME/.profile
. If the ENV
environment variable is set on invocation, $ENV
is sourced after the
profile scripts. The value of ENV
is subjected to parameter expansion,
command substitution, and arithmetic expansion before being interpreted
as a pathname. Note that the PRIVILEGED
option also affects the
execution of startup files.
The following options are set if the shell is invoked as sh
or ksh
:
NO_BAD_PATTERN
, NO_BANG_HIST
, NO_BG_NICE
, NO_EQUALS
,
NO_FUNCTION_ARGZERO
, GLOB_SUBST
, NO_GLOBAL_EXPORT
, NO_HUP
,
INTERACTIVE_COMMENTS
, KSH_ARRAYS
, NO_MULTIOS
, NO_NOMATCH
,
NO_NOTIFY
, POSIX_BUILTINS
, NO_PROMPT_PERCENT
, RM_STAR_SILENT
,
SH_FILE_EXPANSION
, SH_GLOB
, SH_OPTION_LETTERS
, SH_WORD_SPLIT
.
Additionally the BSD_ECHO
and IGNORE_BRACES
options are set if zsh
is invoked as sh
. Also, the KSH_OPTION_PRINT
, LOCAL_OPTIONS
,
PROMPT_BANG
, PROMPT_SUBST
and SINGLE_LINE_ZLE
options are set if
zsh is invoked as ksh
.
4.3 Restricted Shell
When the basename of the command used to invoke zsh starts with the
letter ‘r
’ or the ‘-r
’ command line option is supplied at
invocation, the shell becomes restricted. Emulation mode is determined
after stripping the letter ‘r
’ from the invocation name. The following
are disabled in restricted mode:
- changing directories with the
cd
builtin - changing or unsetting the
EGID
,EUID
,GID
,HISTFILE
,HISTSIZE
,IFS
,LD_AOUT_LIBRARY_PATH
,LD_AOUT_PRELOAD
,LD_LIBRARY_PATH
,LD_PRELOAD
,MODULE_PATH
,module_path
,PATH
,path
,SHELL
,UID
andUSERNAME
parameters - specifying command names containing
/
- specifying command pathnames using
hash
- redirecting output to files
- using the
exec
builtin command to replace the shell with another command - using
jobs -Z
to overwrite the shell process’ argument and environment space - using the
ARGV0
parameter to overrideargv[0]
for external commands - turning off restricted mode with
set +r
orunsetopt RESTRICTED
These restrictions are enforced after processing the startup files. The
startup files should set up PATH
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.
Restricted mode can also be activated any time by setting the
RESTRICTED
option. This immediately enables all the restrictions
described above even if the shell still has not processed all startup
files.
A shell Restricted Mode 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 chroot jails, containers and zones.
A restricted shell is very difficult to implement safely. The feature may be removed in a future version of zsh.
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 ‘PATH
’ variable, it does not prevent
those commands from running any other command.
As an example, if ‘env
’ is among the list of allowed commands, then
it allows the user to run any command as ‘env
’ is not a shell
So when implementing a restricted shell framework it is important to be fully aware of what actions each of the allowed commands or features (which may be regarded as modules) can perform.
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.
If a ‘perl
’, ‘python
’, ‘bash
’, or other general purpose
interpreted script it treated as a restricted command, the user can work
around the restriction by setting specially crafted ‘PERL5LIB
’,
‘PYTHONPATH
’, ‘BASHENV
’ (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
‘GCONV_PATH
’ environment variable. Those are only a few examples.
Bear in mind that, contrary to some other shells, ‘readonly
’ is not a
security feature in zsh as it can be undone and so cannot be used to
mitigate the above.
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 ‘zsh/system
’, ‘zsh/mapfile
’ and ‘zsh/files
’,
allow bypassing most of the restrictions.
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5 Files
5.1 Startup/Shutdown Files
Commands are first read from /etc/zshenv
; this cannot be overridden.
Subsequent behaviour is modified by the RCS
and GLOBAL_RCS
options;
the former affects all startup files, while the second only affects
global startup files (those shown here with an path starting with a
/
). 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 $ZDOTDIR
to re-enable GLOBAL_RCS
. Both RCS
and GLOBAL_RCS
are set by default.
Commands are then read from $ZDOTDIR/.zshenv
.
If the shell is a login shell,
commands are read from /etc/zprofile
and then $ZDOTDIR/.zprofile
.
Then, if the shell is interactive,
commands are read from /etc/zshrc
and then $ZDOTDIR/.zshrc
.
Finally, if the shell is a login shell,
/etc/zlogin
and $ZDOTDIR/.zlogin
are read.
When a login shell exits, the files $ZDOTDIR/.zlogout
and then
/etc/zlogout
are read. This happens with either an explicit exit via
the exit
or logout
commands, or an implicit exit by reading
end-of-file from the terminal. However, if the shell terminates due to
exec
’ing another process, the logout files are not read. These are
also affected by the RCS
and GLOBAL_RCS
options. Note also that the
RCS
option affects the saving of history files, i.e. if RCS
is unset
when the shell exits, no history file will be saved.
If ZDOTDIR
is unset, HOME
is used instead. Files listed above as
being in /etc
may be in another directory, depending on the
installation.
As /etc/zshenv
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 ‘if [[ -o rcs ]]; then ...
’ so that it will not be
executed when zsh is invoked with the ‘-f
’ option.
5.2 Files
$ZDOTDIR/.zshenv
$ZDOTDIR/.zprofile
$ZDOTDIR/.zshrc
$ZDOTDIR/.zlogin
$ZDOTDIR/.zlogout
${TMPPREFIX}*
(default is /tmp/zsh*)
/etc/zshenv
/etc/zprofile
/etc/zshrc
/etc/zlogin
/etc/zlogout
(installation-specific - /etc
is the default)
Any of these files may be pre-compiled with the zcompile
builtin
command (Shell Builtin
Commands). If a
compiled file exists (named for the original file plus the .zwc
extension) and it is newer than the original file, the compiled file
will be used instead.
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6 Shell Grammar
6.1 Simple Commands & Pipelines
A simple command 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 Parameters.
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,
echo foo
is a simple command with arguments.
A pipeline is either a simple command, or a sequence of two or more
simple commands where each command is separated from the next by ‘|
’
or ‘|&
’. Where commands are separated by ‘|
’, the standard output of
the first command is connected to the standard input of the next. ‘|&
’
is shorthand for ‘2>&1 |
’, 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 ‘!
’ in which case the value is the logical
inverse of the value of the last command. For example,
echo foo | sed 's/foo/bar/'
is a pipeline, where the output (‘foo
’ plus a newline) of the first
command will be passed to the input of the second.
If a pipeline is preceded by ‘coproc
’, 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 ‘>&p
’ and
‘<&p
’ redirection operators or with ‘print -p
’ and ‘read -p
’. A
pipeline cannot be preceded by both ‘coproc
’ and ‘!
’. If job control
is active, the coprocess can be treated in other than input and output
as an ordinary background job.
A sublist is either a single pipeline, or a sequence of two or more
pipelines separated by ‘&&
’ or ‘||
’. If two pipelines are separated
by ‘&&
’, the second pipeline is executed only if the first succeeds
(returns a zero status). If two pipelines are separated by ‘||
’, 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,
dmesg | grep panic && print yes
is a sublist consisting of two pipelines, the second just a simple
command which will be executed if and only if the grep
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 print
(almost certainly
zero).
A list is a sequence of zero or more sublists, in which each sublist
is terminated by ‘;
’, ‘&
’, ‘&|
’, ‘&!
’, 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 ‘(
...)
’ or
‘{
...}
’. When a sublist is terminated by ‘;
’ or newline, the
shell waits for it to finish before executing the next sublist. If a
sublist is terminated by a ‘&
’, ‘&|
’, or ‘&!
’, 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.
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.
6.2 Precommand Modifiers
A simple command may be preceded by a precommand modifier, which will
alter how the command is interpreted. These modifiers are shell builtin
commands with the exception of nocorrect
which is a reserved word.
-
The command is executed with a ‘-
’ prepended to its argv[0]
string.
builtin
The command word is taken to be the name of a builtin command, rather than a shell function or external command.
command
[ -pvV
]
The command word is taken to be the name of an external command, rather
than a shell function or builtin. If the POSIX_BUILTINS
option is set,
builtins will also be executed but certain special properties of them
are suppressed. The -p
flag causes a default path to be searched
instead of that in $path
. With the -v
flag, command
is similar to
whence
and with -V
, it is equivalent to whence -v
.
exec
[ -cl
] [ -a
argv0
]
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 TRAPEXIT
, nor does it
source zlogout
files. The options are provided for compatibility with
other shells.
The -c
option clears the environment.
The -l
option is equivalent to the -
precommand modifier, to treat
the replacement command as a login shell; the command is executed with a
-
prepended to its argv[0]
string. This flag has no effect if used
together with the -a
option.
The -a
option is used to specify explicitly the argv[0]
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 ARGV0
environment variable.
nocorrect
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.
noglob
Filename generation (globbing) is not performed on any of the words.
6.3 Complex Commands
A complex command in zsh is one of the following:
if
list
then
list
[ elif
list
then
list
] ... [
else
list
] fi
The if
list
is executed, and if it returns a zero exit status, the
then
list
is executed. Otherwise, the elif
list
is executed and
if its status is zero, the then
list
is executed. If each elif
list
returns nonzero status, the else
list
is executed.
for
name
... [ in
word
... ] term
do
list
done
Expand the list of word
s, and set the parameter name
to each of them
in turn, executing list
each time. If the ‘in
word
’ is omitted,
use the positional parameters instead of the word
s.
The term
consists of one or more newline or ;
which terminate the
word
s, and are optional when the ‘in
word
’ is omitted.
More than one parameter name
can appear before the list of word
s. If
N
name
s are given, then on each execution of the loop the next N
word
s are assigned to the corresponding parameters. If there are more
name
s than remaining word
s, the remaining parameters are each set to
the empty string. Execution of the loop ends when there is no remaining
word
to assign to the first name
. It is only possible for in
to
appear as the first name
in the list, else it will be treated as
marking the end of the list.
for ((
[expr1
] ;
[expr2
] ;
[expr3
] )) do
list
done
The arithmetic expression expr1
is evaluated first (see Arithmetic
Evaluation). The
arithmetic expression expr2
is repeatedly evaluated until it evaluates
to zero and when non-zero, list
is executed and the arithmetic
expression expr3
evaluated. If any expression is omitted, then it
behaves as if it evaluated to 1.
while
list
do
list
done
Execute the do
list
as long as the while
list
returns a zero
exit status.
until
list
do
list
done
Execute the do
list
as long as until
list
returns a nonzero exit
status.
repeat
word
do
list
done
word
is expanded and treated as an arithmetic expression, which must
evaluate to a number n
. list
is then executed n
times.
The repeat
syntax is disabled by default when the shell starts in a
mode emulating another shell. It can be enabled with the command
‘enable -r repeat
’
case
word
in
[ [(
] pattern
[ |
pattern
] ... )
list
(;;
|;&
|;|
) ] ... esac
Execute the list
associated with the first pattern
that matches
word
, if any. The form of the patterns is the same as that used for
filename generation. See Filename
Generation.
Note further that, unless the SH_GLOB
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 SH_GLOB
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).
If the list
that is executed is terminated with ;&
rather than ;;
,
the following list is also executed. The rule for the terminator of the
following list ;;
, ;&
or ;|
is applied unless the esac
is
reached.
If the list
that is executed is terminated with ;|
the shell
continues to scan the pattern
s looking for the next match, executing
the corresponding list
, and applying the rule for the corresponding
terminator ;;
, ;&
or ;|
. Note that word
is not re-expanded; all
applicable pattern
s are tested with the same word
.
select
name
[ in
word
... term
] do
list
done
where term
is one or more newline or ;
to terminate the word
s.
Print the set of word
s,
each preceded by a number. If the in
word
is omitted, use the
positional parameters. The PROMPT3
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 word
s, then the parameter name
is set to the
word
corresponding to this number. If this line is empty, the
selection list is printed again. Otherwise, the value of the parameter
name
is set to null. The contents of the line read from standard input
is saved in the parameter REPLY
. list
is executed for each selection
until a break or end-of-file is encountered.
(
list
)
Execute list
in a subshell. Traps set by the trap
builtin are reset
to their default values while executing list
.
{
list
}
Execute list
.
{
try-list
} always {
always-list
}
First execute try-list
. Regardless of errors, or break
or continue
commands encountered within try-list
, execute always-list
. Execution
then continues from the result of the execution of try-list
; in other
words, any error, or break
or continue
command is treated in the
normal way, as if always-list
were not present. The two chunks of code
are referred to as the ‘try block’ and the ‘always block’.
Optional newlines or semicolons may appear after the always
; note,
however, that they may not appear between the preceding closing brace
and the always
.
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 always-list
to be executed. For example, an erroneously
constructed if
block in try-list
would cause the shell to abort
during parsing, so that always-list
would not be executed, while an
erroneous substitution such as ${*foo*}
would cause a run-time error,
after which always-list
would be executed.
An error condition can be tested and reset with the special integer
variable TRY_BLOCK_ERROR
. Outside an always-list
the value is
irrelevant, but it is initialised to -1
. Inside always-list
, the
value is 1 if an error occurred in the try-list
, else 0. If
TRY_BLOCK_ERROR
is set to 0 during the always-list
, the error
condition caused by the try-list
is reset, and shell execution
continues normally after the end of always-list
. Altering the value
during the try-list
is not useful (unless this forms part of an
enclosing always
block).
Regardless of TRY_BLOCK_ERROR
, after the end of always-list
the
normal shell status $?
is the value returned from try-list
. This
will be non-zero if there was an error, even if TRY_BLOCK_ERROR
was
set to zero.
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.
{
# 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.
When a try
block occurs outside of any function, a return
or a
exit
encountered in try-list
does not cause the execution of
always-list
. Instead, the shell exits immediately after any EXIT
trap has been executed. Otherwise, a return
command encountered in
try-list
will cause the execution of always-list
, just like break
and continue
.
function
word
... [ ()
] [ term
] {
list
}
word
... ()
[ term
] {
list
}
word
... ()
[ term
] command
where term
is one or more newline or ;
. Define a function which is
referenced by any one of word
. Normally, only one word
is provided;
multiple word
s are usually only useful for setting traps. The body of
the function is the list
between the {
and }
. See
Functions.
If the option SH_GLOB
is set for compatibility with other shells, then
whitespace may appear between the left and right parentheses when there
is a single word
; otherwise, the parentheses will be treated as
forming a globbing pattern in that case.
In any of the forms above, a redirection may appear outside the function body, for example
func() { ... } 2>&1
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.
time
[ pipeline
]
The pipeline
is executed, and timing statistics are reported on the
standard error in the form specified by the TIMEFMT
parameter. If
pipeline
is omitted, print statistics about the shell process and its
children.
[[
exp
]]
Evaluates the conditional expression exp
and return a zero exit status
if it is true. See Conditional
Expressions for a
description of exp
.
6.4 Alternate Forms For Complex Commands
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.
The short versions below only work if sublist
is of the form ‘{
list
}
’ or if the SHORT_LOOPS
option is set. For the if
, while
and until
commands, in both these cases the test part of the loop must
also be suitably delimited, such as by ‘[[
...
]]
’ or ‘((
...
))
’, else the end of the test will not be recognized. For the for
,
repeat
, case
and select
commands no such special form for the
arguments is necessary, but the other condition (the special form of
sublist
or use of the SHORT_LOOPS
option) still applies.
-
if
list
{
list
}
[elif
list
{
list
}
] ... [else {
list
}
]
An alternate form ofif
. The rules mean thatif [[ -o ignorebraces ]] { print yes }
works, but
if true { # Does not work! print yes }
does not, since the test is not suitably delimited.
-
if
list
sublist
A short form of the alternateif
. The same limitations on the form oflist
apply as for the previous form. -
for
name
...(
word
...)
sublist
A short form offor
. -
for
name
... [in
word
... ]term
sublist
whereterm
is at least one newline or;
. Another short form offor
. -
for ((
[expr1
];
[expr2
];
[expr3
]))
sublist
A short form of the arithmeticfor
command. -
foreach
name
...(
word
...)
list
end
Another form offor
. -
while
list
{
list
}
An alternative form ofwhile
. Note the limitations on the form oflist
mentioned above. -
until
list
{
list
}
An alternative form ofuntil
. Note the limitations on the form oflist
mentioned above. -
repeat
word
sublist
This is a short form ofrepeat
. -
case
word
{
[ [(
]pattern
[|
pattern
] ...)
list
(;;
|;&
|;|
) ] ...}
An alternative form ofcase
. -
select
name
[in
word
...term
]sublist
whereterm
is at least one newline or;
. A short form ofselect
. -
function
word
... [()
] [term
]sublist
This is a short form offunction
.
6.5 Reserved Words
The following words are recognized as reserved words when used as the
first word of a command unless quoted or disabled using disable -r
:
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
Additionally, ‘}
’ is recognized in any position if neither the
IGNORE_BRACES
option nor the IGNORE_CLOSE_BRACES
option is set.
6.6 Errors
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 CONTINUE_ON_ERROR
.
Fatal errors found in non-interactive shells include:
- Failure to parse shell options passed when invoking the shell
- Failure to change options with the
set
builtin - Parse errors of all sorts, including failures to parse mathematical expressions
- Failures to set or modify variable behaviour with
typeset
,local
,declare
,export
,integer
,float
- Execution of incorrectly positioned loop control structures
(
continue
,break
) - Attempts to use regular expression with no regular expression module available
- Disallowed operations when the
RESTRICTED
options is set - Failure to create a pipe needed for a pipeline
- Failure to create a multio
- Failure to autoload a module needed for a declared shell feature
- Errors creating command or process substitutions
- Syntax errors in glob qualifiers
- File generation errors where not caught by the option
BAD_PATTERN
- All bad patterns used for matching within case statements
- File generation failures where not caused by
NO_MATCH
or similar options - All file generation errors where the pattern was used to create a multio
- Memory errors where detected by the shell
- Invalid subscripts to shell variables
- Attempts to assign read-only variables
- Logical errors with variables such as assignment to the wrong type
- Use of invalid variable names
- Errors in variable substitution syntax
- Failure to convert characters in
$’
...’
expressions
If the POSIX_BUILTINS
option is set, more errors associated with shell
builtin commands are treated as fatal, as specified by the POSIX
standard.
6.7 Comments
In non-interactive shells, or in interactive shells with the
INTERACTIVE_COMMENTS
option set, a word beginning with the third
character of the histchars
parameter (‘#
’ by default) causes that
word and all the following characters up to a newline to be ignored.
6.8 Aliasing
Every eligible word 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.
An alias is defined using
the alias
builtin; global aliases may be defined using the -g
option
to that builtin.
A word is defined as:
- Any plain string or glob pattern
- Any quoted string, using any quoting method (note that the quotes must be part of the alias definition for this to be eligible)
- Any parameter reference or command substitution
- Any series of the foregoing, concatenated without whitespace or other tokens between them
- Any reserved word (
case
,do
,else
, etc.) - With global aliasing, any command separator, any redirection
operator, and ‘
(
’ or ‘)
’ when not part of a glob pattern
Alias expansion is done on the shell input before any other expansion
except history expansion. Therefore, if an alias is defined for the word
foo
, alias expansion may be avoided by quoting part of the word, e.g.
\foo
. Any form of quoting works, although there is nothing to prevent
an alias being defined for the quoted form such as \foo
as well.
When POSIX_ALIASES
is set, only plain unquoted strings are eligible
for aliasing. The alias
builtin does not reject ineligible aliases,
but they are not expanded.
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. ’foo
; completion
will automatically add the trailing single quote.
6.8.1 Alias difficulties
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.
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 aliases
described in
The zsh/parameter
Module). However, as
noted in the case of POSIX_ALIASES
above, the shell does not attempt
to deduce whether the string corresponds to a word at the time the alias
is created.
For example, an expression containing an =
at the start of a command
line is an assignment and cannot be expanded as an alias; a lone =
is
not an assignment but can only be set as an alias using the parameter,
as otherwise the =
is taken part of the syntax of the builtin command.
It is not presently possible to alias the ‘((
’ token that introduces
arithmetic expressions, because until a full statement has been parsed,
it cannot be distinguished from two consecutive ‘(
’ tokens introducing
nested subshells. Also, if a separator such as &&
is aliased, \&&
turns into the two tokens \&
and &
, each of which may have been
aliased separately. Similarly for \<<
, \>|
, etc.
There is a commonly encountered problem with aliases illustrated by the following code:
alias echobar='echo bar'; echobar
This prints a message that the command echobar
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 echobar
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 ‘source
’ or ‘.
’.
Consequently, use of functions rather than aliases is recommended in
non-interactive code.
Note also the unhelpful interaction of aliases and function definitions:
alias func='noglob func'
func() {
echo Do something with $*
}
Because aliases are expanded in function definitions, this causes the following command to be executed:
noglob func() {
echo Do something with $*
}
which defines noglob
as well as func
as functions with the body
given. To avoid this, either quote the name func
or use the
alternative function definition form ‘function func
’. Ensuring the
alias is defined after the function works but is problematic if the code
fragment might be re-executed.
6.9 Quoting
A character may be quoted (that is, made to stand for itself) by
preceding it with a ‘\
’. ‘\
’ followed by a newline is ignored.
A string enclosed between ‘$’
’ and ‘’
’ is processed the same way as
the string arguments of the print
builtin, and the resulting string is
considered to be entirely quoted. A literal ‘’
’ character can be
included in the string by using the ‘\’
’ escape.
All characters enclosed between a pair of single quotes (’’
) that is
not preceded by a ‘$
’ are quoted. A single quote cannot appear within
single quotes unless the option RC_QUOTES
is set, in which case a pair
of single quotes are turned into a single quote. For example,
print ''''
outputs nothing apart from a newline if RC_QUOTES
is not set, but one
single quote if it is set.
Inside double quotes (""
), parameter and command substitution occur,
and ‘\
’ quotes the characters ‘\
’, ‘‘
’, ‘"
’, ‘$
’, and the
first character of $histchars
(default ‘!
’).
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
7 Redirection
If a command is followed by &
and job control is not active, then the
default standard input for the command is the empty file /dev/null
.
Otherwise, the environment for the execution of a command contains the
file descriptors of the invoking shell as modified by input/output
specifications.
The following may appear anywhere in a simple command or may precede or
follow a complex command. Expansion occurs before word
or digit
is
used except as noted below. If the result of substitution on word
produces more than one filename, redirection occurs for each separate
filename in turn.
-
<
word
Open fileword
for reading as standard input. It is an error to open a file in this fashion if it does not exist. -
<>
word
Open fileword
for reading and writing as standard input. If the file does not exist then it is created. -
>
word
Open fileword
for writing as standard output. If the file does not exist then it is created. If the file exists, and theCLOBBER
option is unset, this causes an error; otherwise, it is truncated to zero length. -
>|
word
>!
word
Same as>
, except that the file is truncated to zero length if it exists, regardless ofCLOBBER
. -
>>
word
Open fileword
for writing in append mode as standard output. If the file does not exist, and theCLOBBER
andAPPEND_CREATE
options are both unset, this causes an error; otherwise, the file is created. -
>>|
word
>>!
word
Same as>>
, except that the file is created if it does not exist, regardless ofCLOBBER
andAPPEND_CREATE
. -
<<
[-
]word
The shell input is read up to a line that is the same asword
, or to an end-of-file. No parameter expansion, command substitution or filename generation is performed onword
. The resulting document, called a here-document, becomes the standard input.If any character of
word
is quoted with single or double quotes or a ‘\
’, no interpretation is placed upon the characters of the document. Otherwise, parameter and command substitution occurs, ‘\
’ followed by a newline is removed, and ‘\
’ must be used to quote the characters ‘\
’, ‘$
’, ‘‘
’ and the first character ofword
.Note that
word
itself does not undergo shell expansion. Backquotes inword
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$’``...``’
have their standard effect of expanding backslashed references to special characters.If
<<-
is used, then all leading tabs are stripped fromword
and from the document. -
<<<
word
Perform shell expansion onword
and pass the result to standard input. This is known as a here-string. Compare the use ofword
in here-documents above, whereword
does not undergo shell expansion. -
<&
number
>&
number
The standard input/output is duplicated from file descriptornumber
(see man page dup2(2)). -
<& -
>& -
Close the standard input/output. -
<& p
>& p
The input/output from/to the coprocess is moved to the standard input/output. -
>&
word
&>
word
(Except where ‘>&
word
’ matches one of the above syntaxes; ‘&>
’ can always be used to avoid this ambiguity.) Redirects both standard output and standard error (file descriptor 2) in the manner of ‘>
word
’. Note that this does not have the same effect as ‘>
word
2>&1
’ in the presence of multios (see the section below). -
>&|
word
>&!
word
&>|
word
&>!
word
Redirects both standard output and standard error (file descriptor- in the manner of ‘
>|
word
’.
- in the manner of ‘
-
>>&
word
&>>
word
Redirects both standard output and standard error (file descriptor- in the manner of ‘
>>
word
’.
- in the manner of ‘
-
>>&|
word
>>&!
word
&>>|
word
&>>!
word
Redirects both standard output and standard error (file descriptor- in the manner of ‘
>>|
word
’.
- in the manner of ‘
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
- The order in which redirections are specified is significant. The shell evaluates each redirection in terms of the (file descriptor, file) association at the time of evaluation. For example:
...
1>``fname
2>&1
first associates file descriptor 1 with file fname
. It then associates
file descriptor 2 with the file associated with file descriptor 1 (that
is, fname
). 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 fname
.
The ‘|&
’ command separator described in Simple Commands &
Pipelines is a
shorthand for ‘2>&1 |
’.
The various forms of process substitution, ‘<(``list``)
’, and
‘=(``list``)
’ for input and ‘>(``list``)
’ for output, are often
used together with redirection. For example, if word
in an output
redirection is of the form ‘>(``list``)
’ then the output is piped to
the command represented by list
. See Process
Substitution.
7.1 Opening file descriptors using parameters
When the shell is parsing arguments to a command, and the shell option
IGNORE_BRACES
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:
...
{myfd}>&1
This opens a new file descriptor that is a duplicate of file descriptor
1 and sets the parameter myfd
to the number of the file descriptor,
which will be at least 10. The new file descriptor can be written to
using the syntax >&$myfd
. The file descriptor remains open in
subshells
The syntax {``varid``}>&-
, for example {myfd}>&-
, may be used to
close a file descriptor opened in this fashion. Note that the parameter
given by varid
must previously be set to a file descriptor in this
case.
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 <&$``param
or >&$``param
if param
is
readonly.
If the option CLOBBER
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.
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
exec
. 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.
The following shows a typical sequence of allocation, use, and closing of a file descriptor:
integer myfd
exec {myfd}>~/logs/mylogfile.txt
print This is a log message. >&$myfd
exec {myfd}>&-
Note that the expansion of the variable in the expression >&$myfd
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.
7.2 Multios
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
MULTIOS
option is set, as it is by default. Thus:
date >foo >bar
writes the date to two files, named ‘foo
’ and ‘bar
’. Note that a
pipe is an implicit redirection; thus
date >foo | cat
writes the date to the file ‘foo
’, and also pipes it to cat.
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.
Note also that redirections are always expanded in order. This happens
regardless of the setting of the MULTIOS
option, but with the option
in effect there are additional consequences. For example, the meaning of
the expression >&1
will change after a previous redirection:
date >&1 >output
In the case above, the >&1
refers to the standard output at the start
of the line; the result is similar to the tee
command. However,
consider:
date >output >&1
As redirections are evaluated in order, when the >&1
is encountered
the standard output is set to the file output
and another copy of the
output is therefore sent to that file. This is unlikely to be what is
intended.
If the MULTIOS
option is set, the word after a redirection operator is
also subjected to filename generation (globbing). Thus
: > *
will truncate all files in the current directory, assuming there’s at
least one. (Without the MULTIOS
option, it would create an empty file
called ‘*
’.) Similarly, you can do
echo exit 0 >> *.sh
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 MULTIOS
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 cat
, so if strictly standard behaviour is
needed, cat
should be used instead.
Thus
sort <foo <fubar
or even
sort <f{oo,ubar}
is equivalent to ‘cat foo fubar | sort
’.
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 >&$myfd
.
Note that a pipe is an implicit redirection; thus
cat bar | sort <foo
is equivalent to ‘cat bar foo | sort
’ (note the order of the inputs).
If the MULTIOS
option is unset, each redirection replaces the
previous redirection for that file descriptor. However, all files
redirected to are actually opened, so
echo Hello > bar > baz
when MULTIOS
is unset will truncate ‘bar
’, and write ‘Hello
’ into
‘baz
’.
There is a problem when an output multio is attached to an external program. A simple example shows this:
cat file >file1 >file2
cat file1 file2
Here, it is possible that the second ‘cat
’ will not display the full
contents of file1
and file2
(i.e. the original contents of file
repeated twice).
The reason for this is that the multios are spawned after the cat
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 file1
and file2
are completely written. As a
workaround, it is possible to run the cat
process as part of a job in
the current shell:
{ cat file } >file >file2
Here, the {``...``}
job will pause to wait for both files to be
written.
7.3 Redirections with no command
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.
If the parameter NULLCMD
is not set or the option CSH_NULLCMD
is
set, an error is caused. This is the csh behavior and CSH_NULLCMD
is
set by default when emulating csh.
If the option SH_NULLCMD
is set, the builtin ‘:
’ is inserted as a
command with the given redirections. This is the default when emulating
sh or ksh.
Otherwise, if the parameter NULLCMD
is set, its value will be used as
a command with the given redirections. If both NULLCMD
and
READNULLCMD
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
NULLCMD
is ‘cat
’ and for READNULLCMD
is ‘more
’. Thus
< file
shows the contents of file
on standard output, with paging if that is
a terminal. NULLCMD
and READNULLCMD
may refer to shell functions.
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8 Command Execution
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 Functions. If there exists a shell builtin by that name, the builtin is invoked.
Otherwise, the shell searches each element of $path
for a search is
unsuccessful, the shell prints an error message and returns a nonzero
exit status.
and the file is not a directory, it is assumed to be a shell script.
/bin/sh
is spawned to execute it. If the program is a file beginning
with ‘#!
’, the remainder of the first line specifies an interpreter
for the program. The shell will execute the specified interpreter on
operating systems that do
If no external command is found but a function
command_not_found_handler
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
‘command not found:
cmd
’ 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.
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9 Functions
Shell functions are defined with the function
reserved word or the
special syntax ‘funcname
()
’. 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 Command
Execution.)
Functions execute in the same process as the caller and share all files
and present working directory with the caller. A trap on EXIT
set
inside a function is executed after the function completes in the
environment of the caller.
The return
builtin is used to return from function calls.
Function identifiers can be listed with the functions
builtin.
Functions can be
undefined with the unfunction
builtin.
9.1 Autoloading Functions
A function can be marked as undefined using the autoload
builtin (or
‘functions -u
’ or ‘typeset -fu
’). Such a function has no body. When
the function is first executed, the shell searches for its definition
using the elements of the fpath
variable. Thus to define functions for
autoloading, a typical sequence is:
fpath=(~/myfuncs $fpath)
autoload myfunc1 myfunc2 ...
The usual alias expansion during reading will be suppressed if the
autoload
builtin or its equivalent is given the option -U
. This is
recommended for the use of functions supplied with the zsh distribution.
Note that for functions
precompiled with the zcompile
builtin command the flag -U
must be
provided when the .zwc
file is created, as the corresponding
information is compiled into the latter.
For each element
in fpath
, the shell looks for three possible files,
the newest of which is used to load the definition for the function:
-
element``.zwc
A file created with thezcompile
builtin command, which is expected to contain the definitions for all functions in the directory namedelement
. 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.If
element
already includes a.zwc
extension (i.e. the extension was explicitly given by the user),element
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 namedelement
without the suffix. Thus including an element such as ‘/usr/local/funcs.zwc
’ infpath
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. -
element``/``function``.zwc
A file created withzcompile
, which is expected to contain the definition forfunction
. It may include other function definitions as well, but those are neither loaded nor executed; a file found in this way is searched only for the definition offunction
. -
element``/``function
A file of zsh command text, taken to be the definition forfunction
.
In summary, the order of searching is, first, in the parents of
directories in fpath
for the newer of either a compiled directory or a
directory in fpath
; second, if more than one of these contains a
definition for the function that is sought, the leftmost in the fpath
is chosen; and third, within a directory, the newer of either a compiled
function or an ordinary function definition is used.
If the KSH_AUTOLOAD
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.
Otherwise, the function body (with no surrounding ‘funcname``() {``...``}
’) 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.
For example, suppose the autoload file func
contains
func() { print This is func; }
print func is initialized
then ‘func; func
’ with KSH_AUTOLOAD
set will produce both messages
on the first call, but only the message ‘This is func
’ on the second
and subsequent calls. Without KSH_AUTOLOAD
set, it will produce the
initialization message on the first call, and the other message on the
second and subsequent calls.
It is also possible to create a function that is not marked as
autoloaded, but which loads its own definition by searching fpath
, by
using ‘autoload -X
’ within a shell function. For example, the
following are equivalent:
myfunc() {
autoload -X
}
myfunc args...
and
unfunction myfunc # if myfunc was defined
autoload myfunc
myfunc args...
In fact, the functions
command outputs ‘builtin autoload -X
’ as the
body of an autoloaded function. This is done so that
eval "$(functions)"
produces a reasonable result. A true autoloaded function can be
identified by the presence of the comment ‘# undefined
’ in the body,
because all comments are discarded from defined functions.
To load the definition of an autoloaded function myfunc
without
executing myfunc
, use:
autoload +X myfunc
9.2 Anonymous Functions
If no name is given for a function, it is ‘anonymous’ and is handled
specially. Either form of function definition may be used: a ‘()
’ with
no preceding name, or a ‘function
’ 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
‘(anon)
’.
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 $0
) are set. This is a difference from the way
other functions are parsed: normal function definitions may be followed
by certain keywords such as ‘else
’ or ‘fi
’, which will be treated as
arguments to anonymous functions, so that a newline or semicolon is
needed to force keyword interpretation.
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).
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.
For example,
variable=outside
function {
local variable=inside
print "I am $variable with arguments $*"
} this and that
print "I am $variable"
outputs the following:
I am inside with arguments this and that
I am outside
Note that function definitions with arguments that expand to nothing,
for example ‘name=; function $name { ``...`` }
’, are not treated
as anonymous functions. Instead, they are treated as normal function
definitions where the definition is silently discarded.
9.3 Special Functions
Certain functions, if defined, have special meaning to the shell.
9.3.1 Hook Functions
For the functions below, it is possible to define an array that has the
same name as the function with ‘_functions
’ 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 $chpwd_functions
is an array containing the
values ‘mychpwd
’, ‘chpwd_save_dirstack
’, then the shell attempts to
execute the functions ‘chpwd
’, ‘mychpwd
’ and
‘chpwd_save_dirstack
’, 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 precmd
hook causes an immediately following periodic
function not
to run (though it may run at the next opportunity).
chpwd
Executed whenever the current working directory is changed.
periodic
If the parameter PERIOD
is set, this function is executed every
$PERIOD
seconds, just before a prompt. Note that if multiple functions
are defined using the array periodic_functions
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.
precmd
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.
preexec
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.
zshaddhistory
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).
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.
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.
A hook function may call ‘fc -p
...
’ to switch the history context
so that the history is saved in a different file from the that in the
global HISTFILE
parameter. This is handled specially: the history
context is automatically restored after the processing of the history
line is finished.
The following example function works with one of the options
INC_APPEND_HISTORY
or SHARE_HISTORY
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.
zshaddhistory() {
print -sr -- ${1%%$'\n'}
fc -p .zsh_local_history
}
zshexit
Executed at the point where the main shell is about to exit normally.
This is not called by exiting subshells, nor when the exec
precommand
modifier is used before an external command. Also, unlike TRAPEXIT
, it
is not called when functions exit.
9.3.2 Trap Functions
The functions below are treated specially but do not have corresponding hook arrays.
-
TRAP``NAL
If defined and non-null, this function will be executed whenever the shell catches a signal
SIG``NAL
, whereNAL
is a signal name as specified for thekill
builtin. The signal number will be passed as the first parameter to the function.If a function of this form is defined and null, the shell and processes spawned by it will ignore
SIG``NAL
.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.
Programs terminated by uncaught signals typically return the status 128 plus the signal number. Hence the following causes the handler for
SIGINT
to print a message, then mimic the usual effect of the signal.TRAPINT() { print "Caught SIGINT, aborting." return $(( 128 + $1 )) }
The functions
TRAPZERR
,TRAPDEBUG
andTRAPEXIT
are never executed inside other traps. -
TRAPDEBUG
If the optionDEBUG_BEFORE_CMD
is set (as it is by default), executed before each command; otherwise executed after each command. See the description of thetrap
builtin in Shell Builtin Commands for details of additional features provided in debug traps. -
TRAPEXIT
Executed when the shell exits, or when the current function exits if defined inside a function. The value of$?
at the start of execution is the exit status of the shell or the return status of the function exiting. -
TRAPZERR
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 ‘&&
’ or ‘||
’; only the final command in a sublist of this type causes the trap to be executed. The functionTRAPERR
acts the same asTRAPZERR
on systems where there is noSIGERR
(this is the usual case).
The functions beginning ‘TRAP
’ may alternatively be defined with the
trap
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
TRAPNAL() {
# code
}
(’function traps’) and
trap '
# code
' NAL
(’list traps’) are equivalent in most ways, the exceptions being the following:
- 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.
- 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.
- Function traps are not reset within subshells, in accordance with zsh behaviour; list traps are reset, in accordance with POSIX behaviour.
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10 Jobs & Signals
10.1 Jobs
If the MONITOR
option is set, an interactive shell associates a job
with each pipeline. command, and assigns them small integer numbers.
When a job is started asynchronously with ‘&
’, the shell prints a line
to standard error which looks like:
[1] 1234
indicating that the job which was started asynchronously was job number 1 and had one (top-level) process, whose process ID was 1234.
If a job is started with ‘&|
’ or ‘&!
’, then that job is immediately
disowned. After startup, it to the job control features described here.
If you are running a job and wish to do something else you may hit the
key ^Z (control-Z) which sends a TSTP
signal to the current job: this
key may be redefined by the susp
option of the external stty
command.
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,
putting it in the background
with the bg
command, or run some other commands and then eventually
bring the job back into the foreground with
the foreground command fg
. A
^Z takes effect immediately and is like an interrupt in that pending
output and unread input are discarded when it is typed.
A job being run in the background will suspend if it tries to read from the terminal.
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 fg
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.
One additional side effect is that use of disown
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.
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
if
, for
, etc., in order that the entire block of code can be managed
as a single job.
Background
jobs are normally allowed to produce output, but this can be disabled by
giving the command ‘stty tostop
’. 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.
When a command is suspended and continued later with the fg
or wait
builtins, zsh restores tty modes that were in effect when it was
suspended. This (intentionally) does not apply if the command is
continued via ‘kill -CONT
’, nor when it is continued with bg
.
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:
-
%``number
The job with the given number. -
%``string
The last job whose command line begins withstring
. -
%?``string
The last job whose command line containsstring
. -
%%
Current job. -
%+
Equivalent to ‘%%
’. -
%-
Previous job.
The shell learns immediately whenever a process changes state.
It normally informs you
whenever a job becomes blocked so that no further progress is possible.
If the NOTIFY
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.
When the monitor mode is on, each background job that completes triggers
any trap set for CHLD
.
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
jobs
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 SIGHUP
signal, if the HUP
option is set.
To avoid having the shell terminate the running jobs, either use the
nohup command (see man page nohup(1)) or the disown
builtin.
10.2 Signals
The INT
and QUIT
signals for an invoked command are ignored if the
command is followed by ‘&
’ and the MONITOR
option is not active. The
shell itself always ignores the QUIT
signal. Otherwise, signals have
the values inherited by the shell from its parent (but see the
TRAP``NAL
special functions in Functions).
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 exit
command or exit due to
the option ERR_EXIT
will cause the shell to exit without waiting.
Examples of such asynchronous jobs are process substitution, see
Process Substitution, and the
handler processes for multios, see the section Multios in
Redirection.
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11 Arithmetic Evaluation
The shell can perform integer and floating point arithmetic, either
using the builtin let
, or via a substitution of the form
$((``...``))
. 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 ‘print - $(( 12345678901 ))
’; 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.
The let
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 ‘((
’, all the characters until a
matching ‘))
’ are treated as a quoted expression and arithmetic
expansion performed as for an argument of let
. More precisely,
‘((``...``))
’ is equivalent to ‘let "``...``"
’. 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.
For example, the following statement
(( val = 2 + 1 ))
is equivalent to
let "val = 2 + 1"
both assigning the value 3 to the shell variable val
and returning a
zero status.
Integers can be in bases other than 10. A leading ‘0x
’ or ‘0X
’
denotes hexadecimal and a leading ‘0b
’ or ‘0B
’ binary. Integers may
also be of the form ‘base``#``n
’, where base
is a decimal number
between two and thirty-six representing the arithmetic base and n
is a
number in that base (for example, ‘16#ff
’ is 255 in hexadecimal). The
base``#
may also be omitted, in which case base 10 is used. For
backwards compatibility the form ‘[``base``]``n
’ is also accepted.
An integer expression or a base given in the form ‘base``#``n
’ may
contain underscores (‘_
’) after the leading digit for visual guidance;
these are ignored in computation. Examples are 1_000_000
or
0xffff_ffff
which are equivalent to 1000000
and 0xffffffff
respectively.
It is also possible to specify a base to be used for output in the form
‘[#``base``]
’, for example ‘[#16]
’. 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 ‘-i
base
’ to the typeset
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:
typeset -i 16 y
print $(( [#8] x = 32, y = 32 ))
print $x $y
outputs first ‘8#40
’, the rightmost value in the given output base,
and then ‘8#40 16#20
’, because y
has been explicitly declared to
have output base 16, while x
(assuming it does not already exist) is
implicitly typed by the arithmetic evaluation, where it acquires the
output base 8.
The base
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:
setopt cbases
print $(( [#16_4] 65536 ** 2 ))
outputs ‘0x1_0000_0000
’.
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,
zmodload zsh/mathfunc
print $(( [#_] sqrt(1e7) ))
outputs ‘3_162.277_660_168_379_5
’ (the number of decimal places shown
may vary).
If the C_BASES
option is set, hexadecimal numbers are output in the
standard C format, for example ‘0xFF
’ instead of the usual ‘16#FF
’.
If the option OCTAL_ZEROES
is also set (it is not by default), octal
numbers will be treated similarly and hence appear as ‘077
’ instead of
‘8#77
’. This option has no effect on the output of bases other than
hexadecimal and octal, and these formats are always understood on input.
When an output base is specified using the ‘[#``base``]
’ syntax, an
appropriate base prefix will be output if necessary, so that the value
output is valid syntax for input. If the #
is doubled, for example
‘[##16]
’, then no base prefix is output.
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 e
or E
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.
An arithmetic expression uses nearly the same syntax and associativity of expressions as in C.
In the native mode of operation, the following operators are supported (listed in decreasing order of precedence):
-
+ - ! ~ ++ –
unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement -
<< >>
bitwise shift left, right -
&
bitwise AND -
^
bitwise XOR -
|
bitwise OR -
**
exponentiation -
* / %
multiplication, division, modulus (remainder) -
+ -
addition, subtraction -
< > <= >=
comparison -
== !=
equality and inequality -
&&
logical AND -
|| ^^
logical OR, XOR -
? :
ternary operator -
= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
assignment -
,
comma operator
The operators ‘&&
’, ‘||
’, ‘&&=
’, and ‘||=
’ 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.
With the option C_PRECEDENCES
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:
-
+ - ! ~ ++ –
unary plus/minus, logical NOT, complement, {pre,post}{in,de}crement -
**
exponentiation -
* / %
multiplication, division, modulus (remainder) -
+ -
addition, subtraction -
<< >>
bitwise shift left, right -
< > <= >=
comparison -
== !=
equality and inequality -
&
bitwise AND -
^
bitwise XOR -
|
bitwise OR -
&&
logical AND -
^^
logical XOR -
||
logical OR -
? :
ternary operator -
= += -= *= /= %= &= ^= |= <<= >>= &&= ||= ^^= **=
assignment -
,
comma operator
Note the precedence of exponentiation in both cases is below that of
unary operators, hence ‘-3**2
’ evaluates as ‘9
’, not ‘-9
’. Use
parentheses where necessary: ‘-(3**2)
’. This is for compatibility with
other shells.
Mathematical functions can be called with the syntax
‘func``(``args``)
’, where the function decides if the args
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 zsh/mathfunc
may be loaded with the zmodload
builtin to
provide standard floating point mathematical functions.
An expression of the form ‘##``x
’ where x
is any character sequence
such as ‘a
’, ‘^A
’, or ‘\M-\C-x
’ gives the value of this character
and an expression of the form ‘#``name
’ gives the value of the first
character of the contents of the parameter name
. Character values are
according to the character set used in the current locale; for multibyte
character handling the option MULTIBYTE
must be set. Note that this
form is different from ‘$#``name
’, a standard parameter substitution
which gives the length of the parameter name
. ‘#\
’ is accepted
instead of ‘##
’, but its use is deprecated.
Named parameters and subscripted arrays can be referenced by name within an arithmetic expression without using the parameter expansion syntax. For example,
((val2 = val1 * 2))
assigns twice the value of $val1
to the parameter named val2
.
An internal integer representation of a named parameter can be specified
with the integer
builtin.
Arithmetic evaluation is
performed on the value of each assignment to a named parameter declared
integer in this manner. Assigning a floating point number to an integer
results in rounding towards zero.
Likewise, floating point numbers can be declared with the float
builtin; there are two types, differing only in their output format, as
described for the typeset
builtin. The output format can be bypassed
by using arithmetic substitution instead of the parameter substitution,
i.e. ‘${``float``}
’ uses the defined format, but ‘$((``float``))
’
uses a generic floating point format.
Promotion of integer to floating point values is performed where
necessary. In addition, if any operator which requires an integer
(‘&
’, ‘|
’, ‘^
’, ‘<<
’, ‘>>
’ and their equivalents with
assignment) is given a floating point argument, it will be silently
rounded towards zero except for ‘~
’ which rounds down.
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 6/8
is truncated, in
this being rounded towards 0. The FORCE_FLOAT
shell option can be used
in scripts or functions where floating point evaluation is required
throughout.
Scalar variables can hold integer or floating point values at different times; there is no memory of the numeric type in this case.
If a variable is first assigned in a numeric context without previously
being declared, it will be implicitly typed as integer
or float
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
for (( f = 0; f < 1; f += 0.1 )); do
# use $f
done
if f
has not already been declared, the first assignment will cause it
to be created as an integer, and consequently the operation ‘f += 0.1
’
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 ‘f = 0.0
’. It is therefore best to declare numeric variables with explicit
types.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
12 Conditional Expressions
A conditional expression is used with the [[
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:
-
-a
file
true iffile
exists. -
-b
file
true iffile
exists and is a block special file. -
-c
file
true iffile
exists and is a character special file. -
-d
file
true iffile
exists and is a directory. -
-e
file
true iffile
exists. -
-f
file
true iffile
exists and is a regular file. -
-g
file
true iffile
exists and has its setgid bit set. -
-h
file
true iffile
exists and is a symbolic link. -
-k
file
true iffile
exists and has its sticky bit set. -
-n
string
true if length ofstring
is non-zero. -
-o
option
true if option namedoption
is on.option
may be a single character, in which case it is a single letter option name. (See Specifying Options.)When no option named
option
exists, and thePOSIX_BUILTINS
option hasn’t been set, return 3 with a warning. If that option is set, return 1 with no warning. -
-p
file
true iffile
exists and is a FIFO special file (named pipe). -
-r
file
true iffile
exists and is readable by current process. -
-s
file
true iffile
exists and has size greater than zero. -
-t
fd
true if file descriptor numberfd
is open and associated with a terminal device. (note:fd
is not optional) -
-u
file
true iffile
exists and has its setuid bit set. -
-v
varname
true if shell variablevarname
is set. -
-w
file
-x
file
-z
string
true if length ofstring
is zero. -
-L
file
true iffile
exists and is a symbolic link. -
-O
file
true iffile
exists and is owned by the effective user ID of this process. -
-G
file
true iffile
exists and its group matches the effective group ID of this process. -
-S
file
true iffile
exists and is a socket. -
-N
file
true iffile
exists and its access time is not newer than its modification time. -
file1
-nt
file2
true iffile1
exists and is newer thanfile2
. -
file1
-ot
file2
true iffile1
exists and is older thanfile2
. -
file1
-ef
file2
true iffile1
andfile2
exist and refer to the same file. -
string
=
pattern
string
==
pattern
true ifstring
matchespattern
. The two forms are exactly equivalent. The ‘=
’ form is the traditional shell syntax (and hence the only one generally used with thetest
and[
builtins); the ‘==
’ form provides compatibility with other sorts of computer language. -
string
!=
pattern
true ifstring
does not matchpattern
. -
string
=~
regexp
true ifstring
matches the regular expressionregexp
. If the optionRE_MATCH_PCRE
is setregexp
is tested as a PCRE regular expression using thezsh/pcre
module, else it is tested as a POSIX extended regular expression using thezsh/regex
module. Upon successful match, some variables will be updated; no variables are changed if the matching fails.If the option
BASH_REMATCH
is not set the scalar parameterMATCH
is set to the substring that matched the pattern and the integer parametersMBEGIN
andMEND
to the index of the start and end, respectively, of the match instring
, such that ifstring
is contained in variablevar
the expression ‘${var[$MBEGIN,$MEND]}
’ is identical to ‘$MATCH
’. The setting of the optionKSH_ARRAYS
is respected. Likewise, the arraymatch
is set to the substrings that matched parenthesised subexpressions and the arraysmbegin
andmend
to the indices of the start and end positions, respectively, of the substrings withinstring
. The arrays are not set if there were no parenthesised subexpressions. For example, if the string ‘a short string
’ is matched against the regular expression ‘s(...)t
’, then (assuming the optionKSH_ARRAYS
is not set)MATCH
,MBEGIN
andMEND
are ‘short
’,3
and7
, respectively, whilematch
,mbegin
andmend
are single entry arrays containing the strings ‘hor
’, ‘4
’ and ‘6
’, respectively.If the option
BASH_REMATCH
is set the arrayBASH_REMATCH
is set to the substring that matched the pattern followed by the substrings that matched parenthesised subexpressions within the pattern. -
string1
<
string2
true ifstring1
comes beforestring2
based on ASCII value of their characters. -
string1
>
string2
true ifstring1
comes afterstring2
based on ASCII value of their characters. -
exp1
-eq
exp2
true ifexp1
is numerically equal toexp2
. Note that for purely numeric comparisons use of the((``...``))
builtin described in Arithmetic Evaluation is more convenient than conditional expressions. -
exp1
-ne
exp2
true ifexp1
is numerically not equal toexp2
. -
exp1
-lt
exp2
true ifexp1
is numerically less thanexp2
. -
exp1
-gt
exp2
true ifexp1
is numerically greater thanexp2
. -
exp1
-le
exp2
true ifexp1
is numerically less than or equal toexp2
. -
exp1
-ge
exp2
true ifexp1
is numerically greater than or equal toexp2
. -
(
exp
)
true ifexp
is true. -
!
exp
true ifexp
is false. -
exp1
&&
exp2
true ifexp1
andexp2
are both true. -
exp1
||
exp2
true if eitherexp1
orexp2
is true.
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, [[ $var ]]
is the same as [[ -n $var ]]
. It is recommended that the second, explicit, form be used where
possible.
Normal shell expansion is performed on the file
, string
and
pattern
arguments, but the result of each expansion is constrained to
be a single word, similar to the effect of double quotes.
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 EXTENDED_GLOB
is in effect by
using an explicit glob qualifier of the form (#q)
at the end of the
string. A normal glob qualifier expression may appear between the ‘q
’
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.
This special use of filename generation is only available with the [[
syntax. If the condition occurs within the [
or test
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.
For example,
[[ -n file*(#qN) ]]
produces status zero if and only if there is at least one file in the
current directory beginning with the string ‘file
’. The globbing
qualifier N
ensures that the expression is empty if there is no
matching file.
Pattern metacharacters are active for the pattern
arguments; the
patterns are the same as those used for filename generation, see
Filename Generation, but there is
no special behaviour of ‘/
’ nor initial dots, and no glob qualifiers
are allowed.
In each of the above expressions, if file
is of the form
‘/dev/fd/``n
’, where n
is an integer, then the test applied to the
open file whose descriptor number is n
, even if the underlying system
does not support the /dev/fd
directory.
In the forms which do numeric comparison, the expressions exp
undergo
arithmetic expansion as if they were enclosed in $((``...``))
.
For example, the following:
[[ ( -f foo || -f bar ) && $report = y* ]] && print File exists.
tests if either file foo
or file bar
exists, and if so, if the value
of the parameter report
begins with ‘y
’; if the complete condition
is true, the message ‘File exists.
’ is printed.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
13 Prompt Expansion
13.1 Expansion of Prompt Sequences
Prompt sequences undergo a special form of expansion. This type of
expansion is also available using the -P
option to the print
builtin.
If the PROMPT_SUBST
option is set, the prompt string is first
subjected to parameter expansion, command substitution and
arithmetic expansion. See Expansion.
Certain escape sequences may be recognised in the prompt string.
If the PROMPT_BANG
option is set, a ‘!
’ in the prompt is replaced by
the current history event number. A literal ‘!
’ may then be
represented as ‘!!
’.
If the PROMPT_PERCENT
option is set, certain escape sequences that
start with ‘%
’ are expanded. Many escapes are followed by a single
character, although some of these take an optional integer argument that
should appear between the ‘%
’ and the next character of the sequence.
More complicated escape sequences are available to provide conditional
expansion.
13.2 Simple Prompt Escapes
13.2.1 Special characters
-
%%
A ‘%
’. -
%)
A ‘)
’.
13.2.2 Login information
-
%l
The line (tty) the user is logged in on, without ‘/dev/
’ prefix. If the name starts with ‘/dev/tty
’, that prefix is stripped. -
%M
The full machine hostname. -
%m
The hostname up to the first ‘.
’. An integer may follow the ‘%
’ to specify how many components of the hostname are desired. With a negative integer, trailing components of the hostname are shown. -
%n
$USERNAME
. -
%y
The line (tty) the user is logged in on, without ‘/dev/
’ prefix. This does not treat ‘/dev/tty
’ names specially.
13.2.3 Shell state
-
%#
A ‘#
’ if the shell is running with privileges, a ‘%
’ if not. Equivalent to ‘%(!.#.%%)
’. The definition of ‘privileged’, for these purposes, is that either the effective user ID is zero, or, if POSIX.1e capabilities are supported, that capability vectors. -
%?
The return status of the last command executed just before the prompt. -
%_
The status of the parser, i.e. the shell constructs (like ‘if
’ and ‘for
’) that have been started on the command line. If given an integer number that many strings will be printed; zero or negative or no integer means print as many as there are. This is most useful in promptsPS2
for continuation lines andPS4
for debugging with theXTRACE
option; in the latter case it will also work non-interactively. -
%^
The status of the parser in reverse. This is the same as ‘%_
’ other than the order of strings. It is often used inRPS2
. -
%d
%/
Current working directory. If an integer follows the ‘%
’, it specifies a number of trailing components of the current working directory to show; zero means the whole path. A negative integer specifies leading components, i.e.%-1d
specifies the first component. -
%~
As%d
and%/
, but if the current working directory starts with$HOME
, that part is replaced by a ‘~
’. Furthermore, if it has a named directory as its prefix, that part is replaced by a ‘~
’ followed by the name of the directory, but only if the result is shorter than the full path; Filename Expansion. -
%e
Evaluation depth of the current sourced file, shell function, oreval
. This is incremented or decremented every time the value of%N
is set or reverted to a previous value, respectively. This is most useful for debugging as part of$PS4
. -
%h
%!
Current history event number. -
%i
The line number currently being executed in the script, sourced file, or shell function given by%N
. This is most useful for debugging as part of$PS4
. -
%I
The line number currently being executed in the file%x
. This is similar to%i
, 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. -
%j
The number of jobs. -
%L
The current value of$SHLVL
. -
%N
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$0
. An integer may follow the ‘%
’ to specify a number of trailing path components to show; zero means the full path. A negative integer specifies leading components. -
%x
The name of the file containing the source code currently being executed. This behaves as%N
except that function and eval command names are not shown, instead the file where they were defined. -
%c
%.
%C
Trailing component of the current working directory. An integer may follow the ‘%
’ to get more than one component. Unless ‘%C
’ is used, tilde contraction is performed first. These are deprecated as%c
and%C
are equivalent to%1~
and%1/
, respectively, while explicit positive integers have the same effect as for the latter two sequences.
13.2.4 Date and time
-
%D
The date inyy``-``mm``-``dd
format. -
%T
Current time of day, in 24-hour format. -
%t
%@
Current time of day, in 12-hour, am/pm format. -
%*
Current time of day in 24-hour format, with seconds. -
%w
The date inday``-``dd
format. -
%W
The date inmm``/``dd``/``yy
format. -
%D{``string``}
string
is formatted using thestrftime
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:-
%f
a day of the month -
%K
the hour of the day on the 24-hour clock -
%L
the hour of the day on the 12-hour clock
In addition, if the system supports the POSIX
gettimeofday
system call,%.
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%
; hence%6.
outputs microseconds, and%9.
outputs nanoseconds. (The latter requires a nanosecond-precisionclock_gettime
; systems lacking this will return a value multiplied by the appropriate power of 10.) A typical example of this is the format ‘%D{%H:%M:%S.%.}
’.The GNU extension
%N
is handled as a synonym for%9.
.Additionally, the GNU extension that a ‘
-
’ between the%
and the format character causes a leading zero or space to be stripped is handled directly by the shell for the format charactersd
,f
,H
,k
,l
,m
,M
,S
andy
; any other format characters are provided to the system’s strftime(3) with any leading ‘-
’ 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. -
13.2.5 Visual effects
-
%B
(%b
)
Start (stop) boldface mode. -
%E
Clear to end of line. -
%U
(%u
)
Start (stop) underline mode. -
%S
(%s
)
Start (stop) standout mode. -
%F
(%f
)
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%F
, for example%F{red}
. In the latter case the values allowed are as described for thefg
zle_highlight
attribute; Character Highlighting. This means that numeric colours are allowed in the second format also. -
%K
(%k
)
Start (stop) using a different bacKground colour. The syntax is identical to that for%F
and%f
. -
%{
...%}
Include a string as a literal escape sequence. The string within the braces should not change the cursor position. Brace pairs can nest.A positive numeric argument between the
%
and the{
is treated as described for%G
below. -
%G
Within a%{
...%}
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%{
...%}
sequence together with the appropriate number of%G
sequences to indicate the correct width. An integer between the ‘%
’ and ‘G
’ indicates a character width other than one. Hence%{``seq``%2G%}
outputsseq
and assumes it takes up the width of two standard characters.Multiple uses of
%G
accumulate in the obvious fashion; the position of the%G
is unimportant. Negative integers are not handled.Note that when prompt truncation is in use it is advisable to divide up output into single characters within each
%{
...%}
group so that the correct truncation point can be found.
13.3 Conditional Substrings in Prompts
-
%v
The value of the first element of the
psvar
array parameter. Following the ‘%
’ with an integer gives that element of the array. Negative integers count from the end of the array. -
%(``x``.``true-text``.``false-text``)
Specifies a ternary expression. The character following thex
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 thetrue-text
, except as part of a %-escape sequence. A ‘)
’ may appear in thefalse-text
as ‘%)
’.true-text
andfalse-text
may both contain arbitrarily-nested escape sequences, including further ternary expressions.The left parenthesis may be preceded or followed by a positive integer
n
, which defaults to zero. A negative integer will be multiplied by -1, except as noted below for ‘l
’. The test characterx
may be any of the following:-
!
True if the shell is running with privileges. -
#
True if the effective uid of the current process isn
. -
?
True if the exit status of the last command wasn
. -
_
True if at leastn
shell constructs were started. -
C
/
True if the current absolute path has at leastn
elements relative to the root directory, hence/
is counted as 0 elements. -
c
.
~
True if the current path, with prefix replacement, has at leastn
elements relative to the root directory, hence/
is counted as 0 elements. -
D
True if the month is equal ton
(January = 0). -
d
True if the day of the month is equal ton
. -
e
True if the evaluation depth is at leastn
. -
g
True if the effective gid of the current process isn
. -
j
True if the number of jobs is at leastn
. -
L
True if theSHLVL
parameter is at leastn
. -
l
True if at leastn
characters have already been printed on the current line. Whenn
is negative, true if at leastabs``(``n``)
characters remain before the opposite margin (thus the left margin forRPROMPT
). -
S
True if theSECONDS
parameter is at leastn
. -
T
True if the time in hours is equal ton
. -
t
True if the time in minutes is equal ton
. -
v
True if the arraypsvar
has at leastn
elements. -
V
True if elementn
of the arraypsvar
is set and non-empty. -
w
True if the day of the week is equal ton
(Sunday = 0).
-
-
%<``string``<
%>``string``>
%[``xstring``]
Specifies truncation behaviour for the remainder of the prompt string. The third, deprecated, form is equivalent to ‘%``xstringx
’, i.e.x
may be ‘<
’ or ‘>
’. Thestring
will be displayed in place of the truncated portion of any string; note this does not undergo prompt expansion.The numeric argument, which in the third form may appear immediately after the ‘
[
’, 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 leastn
characters remain before the right margin (left margin forRPROMPT
).The forms with ‘
<
’ truncate at the left of the string, and the forms with ‘>
’ truncate at the right of the string. For example, if the current directory is ‘/home/pike
’, the prompt ‘%8<..<%/
’ will expand to ‘..e/pike
’. In this string, the terminating character (‘<
’, ‘>
’ or ‘]
’), or in fact any character, may be quoted by a preceding ‘\
’; note when usingprint -P
, however, that this must be doubled as the string is also subject to standardprint
processing, in addition to any backslashes removed by a double quoted string: the worst case is therefore ‘print -P "%<\\<<..."
’.If the
string
is longer than the specified truncation length, it will appear in full, completely replacing the truncated string.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 ‘
%(
’ construct, or to the next truncation encountered at the same grouping level (i.e. truncations inside a ‘%(
’ are separate), which ever comes first. In particular, a truncation with argument zero (e.g., ‘%<<
’) marks the end of the range of the string to be truncated while turning off truncation from there on. For example, the prompt ‘%10<...<%~%<<%#
’ will print a truncated representation of the current directory, followed by a ‘%
’ or ‘#
’, followed by a space. Without the ‘%<<
’, those two characters would be included in the string to be truncated. Note that ‘%-0<<
’ is not equivalent to ‘%<<
’ but specifies that the prompt is truncated at the right margin.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 ‘
%-``n``(l.``true-text``.``false-text``)
’ to remove parts of the prompt when the available space is less thann
.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 14 Expansion
14 Expansion
The following types of expansions are performed in the indicated order in five steps:
-
History Expansion
This is performed only in interactive shells. -
Alias Expansion
Aliases are expanded immediately before the command line is parsed as explained in Aliasing. -
Process Substitution
Parameter Expansion
Command Substitution
Arithmetic Expansion
Brace Expansion
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 ‘\
’,‘’
’ and ‘"
’ are removed. -
Filename Expansion
If theSH_FILE_EXPANSION
option is set, the order of expansion is modified for compatibility with sh and ksh. In that case filename expansion is performed immediately after alias expansion, preceding the set of five expansions mentioned above. -
Filename Generation
This expansion, commonly referred to as globbing, is always done last.
The following sections explain the types of expansion in detail.
14.1 History Expansion
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.
Immediately before execution, each command is saved in the history list,
the size of which is controlled by the HISTSIZE
parameter. The one
most recent command is always retained in any case. Each saved command
in the history list is called a history event 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 Prompt
Expansion) is the number that
is to be assigned to the next command.
14.1.1 Overview
A history expansion begins with the first character of the histchars
parameter, which is ‘!
’ by default, and may occur anywhere on the
command line, including inside double quotes (but not inside single
quotes ’...’
or C-style quotes $’...’
nor when escaped with a
backslash).
The first character is followed by an optional event designator (Event Designators) and then an optional word designator (Word Designators); if neither of these designators is present, no history expansion occurs.
Input lines containing history expansions are echoed after being expanded, but before any other expansions take place and before the command is executed. It is this expanded form that is recorded as the history event for later references.
History expansions do not nest.
By default, a history reference with no event designator refers to the
same event as any preceding history reference on that command line; if
it is the only history reference in a command, it refers to the previous
command.
However, if the option CSH_JUNKIE_HISTORY
is set, then every history
reference with no event specification always refers to the previous
command.
For example, ‘!
’ is the event designator for the previous command, so
‘!!:1
’ always refers to the first word of the previous command, and
‘!!$
’ always refers to the last word of the previous command. With
CSH_JUNKIE_HISTORY
set, then ‘!:1
’ and ‘!$
’ function in the same
manner as ‘!!:1
’ and ‘!!$
’, respectively. Conversely, if
CSH_JUNKIE_HISTORY
is unset, then ‘!:1
’ and ‘!$
’ 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.
The character sequence ‘^``foo``^``bar
’ (where ‘^
’ is actually the
second character of the histchars
parameter) repeats the last command,
replacing the string foo
with bar
. More precisely, the sequence
‘^``foo``^``bar``^
’ is synonymous with ‘!!:s``^``foo``^``bar``^
’,
hence other modifiers (see Modifiers) may follow the final
‘^
’. In particular, ‘^``foo``^``bar``^:G
’ performs a global
substitution.
If the shell encounters the character sequence ‘!"
’ in the input, the
history mechanism is temporarily disabled until the current list (see
Shell Grammar) is fully parsed. The
‘!"
’ is removed from the input, and any subsequent ‘!
’ characters
have no special significance.
A less convenient but more comprehensible form of command history
support is provided by the fc
builtin.
14.1.2 Event Designators
An event designator is a reference to a command-line entry in the
history list. In the list below, remember that the initial ‘!’
in each
item may be changed to another character by setting the histchars
parameter.
-
!
Start a history expansion, except when followed by a blank, newline, ‘=
’ or ‘(
’. If followed immediately by a word designator (Word Designators), this forms a history reference with no event designator (Overview). -
!!
Refer to the previous command. By itself, this expansion repeats the previous command. -
!``n
Refer to command-linen
. -
!-``n
Refer to the current command-line minusn
. -
!``str
Refer to the most recent command starting withstr
. -
!?``str
[?
]
Refer to the most recent command containingstr
. The trailing ‘?
’ is necessary if this reference is to be followed by a modifier or followed by any text that is not to be considered part ofstr
. -
!#
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 ‘!#
’ reference. -
!{
...}
Insulate a history reference from adjacent characters (if necessary).
14.1.3 Word Designators
A word designator indicates which word or words of a given command line
are to be included in a history reference. A ‘:
’ usually separates the
event specification from the word designator. It may be omitted only if
the word designator begins with a ‘^
’, ‘$
’, ‘*
’, ‘-
’ or ‘%
’.
Word designators include:
-
0
The first input word (command). -
n
Then
th argument. -
^
The first argument. That is,1
. -
$
The last argument. -
%
The word matched by (the most recent)?``str
search. -
x``-``y
A range of words;x
defaults to0
. -
*
All the arguments, or a null value if there are none. -
x``*
Abbreviates ‘x``-$
’. -
x``-
Like ‘x``*
’ but omitting word$
.
Note that a ‘%
’ word designator works only when used in one of ‘!%
’,
‘!:%
’ or ‘!?``str``?:%
’, and only when used after a !?
expansion
(possibly in an earlier command). Anything else results in an error,
although the error may not be the most obvious one.
14.1.4 Modifiers
After the optional word designator, you can add a sequence of one or
more of the following modifiers, each preceded by a ‘:
’. These
modifiers also work on the result of filename generation and
parameter expansion, except where noted.
-
a
Turn a file name into an absolute path: prepends the current directory, if necessary; remove ‘.
’ path segments; and remove ‘..
’ path segments and the segments that immediately precede them.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
CHASE_DOTS
orCHASE_LINKS
is set. For example, ‘/before/here/../after
’ is always transformed to ‘/before/after
’, regardless of whether ‘/before/here
’ exists or what kind of object (dir, file, symlink, etc.) it is. -
A
Turn a file name into an absolute path as the ‘a
’ modifier does, and then pass the result through therealpath(3)
library function to resolve symbolic links.Note: on systems that do not have a
realpath(3)
library function, symbolic links are not resolved, so on those systems ‘a
’ and ‘A
’ are equivalent.Note:
foo:A
andrealpath(foo)
are different on some inputs. Forrealpath(foo)
semantics, see the ‘P
‘ modifier. -
c
Resolve a command name into an absolute path by searching the command path given by thePATH
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. -
e
Remove all but the part of the filename extension following the ‘.
’; see the definition of the filename extension in the description of ther
modifier below. Note that according to that definition the result will be empty if the string ends with a ‘.
’. -
h
[digits
]
Remove a trailing pathname component, shortening the path by one directory level: this is the ‘head’ of the pathname. This works like ‘dirname
’. If theh
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 ‘/
’ is the first component, so, for example, ifvar=/my/path/to/something
, then${var:h3}
substitutes/my/path
. Consecutive ‘/’s are treated the same as a single ‘/’. In parameter substitution, digits may only be used if the expression is in braces, so for example the short form substitution$var:h2
is treated as${var:h}2
, not as${var:h2}
. 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). -
l
Convert the words to all lowercase. -
p
Print the new command but do not execute it. Only works with history expansion. -
P
Turn a file name into an absolute path, likerealpath(3)
. The resulting path will be absolute, have neither ‘.
’ nor ‘..
’ components, and refer to the same directory entry as the input filename.Unlike
realpath(3)
, non-existent trailing components are permitted and preserved. -
q
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 byeval
. -
Q
Remove one level of quotes from the substituted words. -
r
Remove a filename extension leaving the root name. Strings with no filename extension are not altered. A filename extension is a ‘.
’ followed by any number of characters (including zero) that are neither ‘.
’ nor ‘/
’ and that continue to the end of the string. For example, the extension of ‘foo.orig.c
’ is ‘.c
’, and ‘dir.c/foo
’ has no extension. -
s/``l``/``r
[/
]
Substituter
forl
as described below. The substitution is done only for the first string that matchesl
. For arrays and for filename generation, this applies to each word of the expanded text. See below for further notes on substitutions.The forms ‘
gs/``l``/``r
’ and ‘s/``l``/``r``/:G
’ perform global substitution, i.e. substitute every occurrence ofr
forl
. Note that theg
or:G
must appear in exactly the position shown.See further notes on this form of substitution below.
-
&
Repeat the previouss
substitution. Likes
, may be preceded immediately by ag
. In parameter expansion the&
must appear inside braces, and in filename generation it must be quoted with a backslash. -
t
[digits
]
Remove all leading pathname components, leaving the final component (tail). This works like ‘basename
’. 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. -
u
Convert the words to all uppercase. -
x
Likeq
, but break into words at whitespace. Does not work with parameter expansion.
The s/``l``/``r``/
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 ‘/
’. A
backslash quotes the delimiter character. The character ‘&
’, in the
right-hand-side r
, is replaced by the text from the left-hand-side
l
. The ‘&
’ can be quoted with a backslash. A null l
uses the
previous string either from the previous l
or from the contextual scan
string s
from ‘!?``s
’. You can omit the rightmost delimiter if a
newline immediately follows r
; the rightmost ‘?
’ in a context scan
can similarly be omitted. Note the same record of the last l
and r
is maintained across all forms of expansion.
Note that if a ‘&
’ is used within glob qualifiers an extra backslash
is needed as a &
is a special character in this case.
Also note that the order of expansions affects the interpretation of l
and r
. When used in a history expansion, which occurs before any other
expansions, l
and r
are treated as literal strings (except as
explained for HIST_SUBST_PATTERN
below). When used in parameter
expansion, the replacement of r
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 l
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 ‘:s
’ expression itself is divided into l
and r
sides.
If the option HIST_SUBST_PATTERN
is set, l
is treated as a pattern
of the usual form described in Filename
Generation. 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
(#q:s/``...``/``...``/)
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 NO_BAD_PATTERN
option so will
cause an error.
When HIST_SUBST_PATTERN
is set, l
may start with a #
to indicate
that the pattern must match at the start of the string to be
substituted, and a %
may appear at the start or after an #
to
indicate that the pattern must match at the end of the string to be
substituted. The %
or #
may be quoted with two backslashes.
For example, the following piece of filename generation code with the
EXTENDED_GLOB
option:
print -r -- *.c(#q:s/#%(#b)s(*).c/'S${match[1]}.C'/)
takes the expansion of *.c
and applies the glob qualifiers in the
(#q``...``)
expression, which consists of a substitution modifier
anchored to the start and end of each word (#%
). This turns on
backreferences ((#b)
), so that the parenthesised subexpression is
available in the replacement string as ${match[1]}
. The replacement
string is quoted so that the parameter is not substituted before the
start of filename generation.
The following f
, F
, w
and W
modifiers work only with parameter
expansion and filename generation. They are listed here to provide a
single point of reference for all modifiers.
-
f
Repeats the immediately (without a colon) following modifier until the resulting word doesn’t change any more. -
F:``expr``:
Likef
, but repeats onlyn
times if the expressionexpr
evaluates ton
. Any character can be used instead of the ‘:
’; if ‘(
’, ‘[
’, or ‘{
’ is used as the opening delimiter, the closing delimiter should be ’)
’, ‘]
’, or ‘}
’, respectively. -
w
Makes the immediately following modifier work on each word in the string. -
W:``sep``:
Likew
but words are considered to be the parts of the string that are separated bysep
. Any character can be used instead of the ‘:
’; opening parentheses are handled specially, see above.
14.2 Process Substitution
Each part of a command argument that takes the form ‘<(``list``)
’,
‘>(``list``)
’ or ‘=(``list``)
’ 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.
Note that ‘<<(``list``)
’ is not a special syntax; it is equivalent to
‘< <(``list``)
’, 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.
In the case of the <
or >
forms, the shell runs the commands in
list
as a subprocess of the job executing the shell command line. If
the system supports the /dev/fd
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 >
is selected then writing on this
special file will provide input for list
. If <
is used, then the
file passed as an argument will be connected to the output of the list
process. For example,
paste <(cut -f1 file1) <(cut -f3 file2) |
tee >(process1) >(process2) >/dev/null
cuts fields 1 and 3 from the files file1
and file2
respectively,
pastes the results together, and sends it to the processes process1
and process2
.
If =(``...``)
is used instead of <(``...``)
, then the file passed as
an argument will be the name of a temporary file containing the output
of the list
process. This may be used instead of the <
form for a
program that expects to lseek (see man page lseek(2)) on the input file.
There is an optimisation for substitutions of the form =(<<<``arg``)
,
where arg
is a single-word argument to the here-string redirection
<<<
. This form produces a file name containing the value of arg
after any substitutions have been performed. This is handled entirely
within the current shell. This is effectively the reverse of the special
form $(<``arg``)
which treats arg
as a file name and replaces it
with the file’s contents.
The =
form is useful as both the /dev/fd
and the named pipe
implementation of <(``...``)
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.
Also note that the previous example can be more compactly and
efficiently written (provided the MULTIOS
option is set) as:
paste <(cut -f1 file1) <(cut -f3 file2) > >(process1) > >(process2)
The shell uses pipes instead of FIFOs to implement the latter two process substitutions in the above example.
There is an additional problem with >(``process``)
; when this is
attached to an external command, the parent shell does not wait for
process
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 MULTIOS in
Redirection. Hence in a simplified
version of the example above:
paste <(cut -f1 file1) <(cut -f3 file2) > >(process)
(note that no MULTIOS
are involved), process
will be run
asynchronously as far as the parent shell is concerned. The workaround
is:
{ paste <(cut -f1 file1) <(cut -f3 file2) } > >(process)
The extra processes here are spawned from the parent shell which will wait for their completion.
Another problem arises any time a job with a substitution that requires
a temporary file is disowned by the shell, including the case where
‘&!
’ or ‘&|
’ 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,
(mycmd =(myoutput)) &!
as the forked subshell will wait for the command to finish then remove the temporary file.
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:
() {
print File $1:
cat $1
} =(print This be the verse)
outputs something resembling the following
File /tmp/zsh6nU0kS:
This be the verse
The temporary file created by the process substitution will be deleted when the function exits.
14.3 Parameter Expansion
The character ‘$
’ is used to introduce parameter expansions. See
Parameters for a description of
parameters, including arrays, associative arrays, and subscript notation
to access individual array elements.
Note in particular the fact that words of unquoted parameters are not
automatically split on whitespace unless the option SH_WORD_SPLIT
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.
With default options, after the assignments:
array=("first word" "" "third word")
scalar="only word"
then $array
substitutes two words, ‘first word
’ and ‘third word
’,
and $scalar
substitutes a single word ‘only word
’. Note that second
element of array
was elided. Scalar parameters can be elided too if
their value is null (empty). To avoid elision, use quoting as follows:
"$scalar"
for scalars and "${array[@]}"
or "${(@)array}"
for
arrays. (The last two forms are equivalent.)
Parameter expansions can involve flags, as in ‘${(@kv)aliases}
’, and
other operators, such as ‘${PREFIX:-"/usr/local"}
’. Parameter
expansions can also be nested. These topics will be introduced below.
The full rules are complicated and are noted at the end.
In the expansions discussed below that require a pattern, the form of
the pattern is the same as that used for filename generation; see
Filename Generation. 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 Modifiers in History
Expansion can be applied: for example,
${i:s/foo/bar/}
performs string substitution on the expansion of
parameter $i
.
In the following descriptions, ‘word
’ refers to a single word
substituted on the command line, not necessarily a space delimited word.
-
${``name``}
The value, if any, of the parametername
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 ofname
. In addition, more complicated forms of substitution usually require the braces to be present; exceptions, which only apply if the optionKSH_ARRAYS
is not set, are a single subscript or any colon modifiers appearing after the name, or any of the characters ‘^
’, ‘=
’, ‘~
’, ‘#
’ or ‘+
’ appearing before the name, all of which work with or without braces.If
name
is an array parameter, and theKSH_ARRAYS
option is not set, then the value of each element ofname
is substituted, one element per word. Otherwise, the expansion results in one word only; withKSH_ARRAYS
, this is the first element of an array. No field splitting is done on the result unless theSH_WORD_SPLIT
option is set. See also the flags=
ands:``string``:
. -
${+``name``}
Ifname
is the name of a set parameter ‘1
’ is substituted, otherwise ‘0
’ is substituted. -
${``name``-``word``}
${``name``:-``word``}
Ifname
is set, or in the second form is non-null, then substitute its value; otherwise substituteword
. In the second formname
may be omitted, in which caseword
is always substituted. -
${``name``+``word``}
${``name``:+``word``}
Ifname
is set, or in the second form is non-null, then substituteword
; otherwise substitute nothing. -
${``name``=``word``}
${``name``:=``word``}
${``name``::=``word``}
In the first form, ifname
is unset then set it toword
; in the second form, ifname
is unset or null then set it toword
; and in the third form, unconditionally setname
toword
. In all forms, the value of the parameter is then substituted. -
${``name``?``word``}
${``name``:?``word``}
In the first form, ifname
is set, or in the second form ifname
is both set and non-null, then substitute its value; otherwise, printword
and exit from the shell. Interactive shells instead return to the prompt. Ifword
is omitted, then a standard message is printed.
In any of the above expressions that test a variable and substitute an
alternate word
, note that you can use standard shell quoting in the
word
value to selectively override the splitting done by the
SH_WORD_SPLIT
option and the =
flag, but not splitting by the
s:``string``:
flag.
In the following expressions, when name
is an array and the
substitution is not quoted, or if the ‘(@)
’ flag or the name``[@]
syntax is used, matching and replacement is performed on each array
element separately.
-
${``name``#``pattern``}
${``name``##``pattern``}
If thepattern
matches the beginning of the value ofname
, then substitute the value ofname
with the matched portion deleted; otherwise, just substitute the value ofname
. In the first form, the smallest matching pattern is preferred; in the second form, the largest matching pattern is preferred. -
${``name``%``pattern``}
${``name``%%``pattern``}
If thepattern
matches the end of the value ofname
, then substitute the value ofname
with the matched portion deleted; otherwise, just substitute the value ofname
. In the first form, the smallest matching pattern is preferred; in the second form, the largest matching pattern is preferred. -
${``name``:#``pattern``}
If thepattern
matches the value ofname
, then substitute the empty string; otherwise, just substitute the value ofname
. Ifname
is an array the matching array elements are removed (use the ‘(M)
’ flag to remove the non-matched elements). -
${``name``:|``arrayname``}
Ifarrayname
is the name (N.B., not contents) of an array variable, then any elements contained inarrayname
are removed from the substitution ofname
. If the substitution is scalar, either becausename
is a scalar variable or the expression is quoted, the elements ofarrayname
are instead tested against the entire expression. -
${``name``:*``arrayname``}
Similar to the preceding substitution, but in the opposite sense, so that entries present in both the original substitution and as elements ofarrayname
are retained and others removed. -
${``name``:^``arrayname``}
${``name``:^^``arrayname``}
Zips two arrays, such that the output array is twice as long as the shortest (longest for ‘:^^
’) ofname
andarrayname
, with the elements alternatingly being picked from them. For ‘:^
’, if one of the input arrays is longer, the output will stop when the end of the shorter array is reached. Thus,a=(1 2 3 4); b=(a b); print ${a:^b}
will output ‘
1 a 2 b
’. For ‘:^^
’, then the input is repeated until all of the longer array has been used up and the above will output ‘1 a 2 b 3 a 4 b
’.Either or both inputs may be a scalar, they will be treated as an array of length 1 with the scalar as the only element. If either array is empty, the other array is output with no extra elements inserted.
Currently the following code will output ‘
a b
’ and ‘1
’ as two separate elements, which can be unexpected. The second print provides a workaround which should continue to work if this is changed.a=(a b); b=(1 2); print -l "${a:^b}"; print -l "${${a:^b}}"
-
${``name``:``offset``}
${``name``:``offset``:``length``}
This syntax gives effects similar to parameter subscripting in the form$``name``[``start``,``end``]
, but is compatible with other shells; note that bothoffset
andlength
are interpreted differently from the components of a subscript.If
offset
is non-negative, then if the variablename
is a scalar substitute the contents startingoffset
characters from the first character of the string, and ifname
is an array substitute elements startingoffset
elements from the first element. Iflength
is given, substitute that many characters or elements, otherwise the entire rest of the scalar or array.A positive
offset
is always treated as the offset of a character or element inname
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 optionKSH_ARRAYS
.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.
When positive,
length
counts from theoffset
position toward the end of the scalar or array. When negative,length
counts back from the end. If this results in a position smaller thanoffset
, a diagnostic is printed and nothing is substituted.The option
MULTIBYTE
is obeyed, i.e. the offset and length count multibyte characters where appropriate.offset
andlength
undergo the same set of shell substitutions as for scalar assignment; in addition, they are then subject to arithmetic evaluation. Hence, for exampleprint ${foo:3} print ${foo: 1 + 2} print ${foo:$(( 1 + 2))} print ${foo:$(echo 1 + 2)}
all have the same effect, extracting the string starting at the fourth character of
$foo
if the substitution would otherwise return a scalar, or the array starting at the fourth element if$foo
would return an array. Note that with the optionKSH_ARRAYS
$foo
always returns a scalar (regardless of the use of the offset syntax) and a form such as${foo[*]:3}
is required to extract elements of an array namedfoo
.If
offset
is negative, the-
may not appear immediately after the:
as this indicates the${``name``:-``word``}
form of substitution. Instead, a space may be inserted before the-
. Furthermore, neitheroffset
norlength
may begin with an alphabetic character or&
as these are used to indicate history-style modifiers. To substitute a value from a variable, the recommended approach is to precede it with a$
as this signifies the intention (parameter substitution can easily be rendered unreadable); however, as arithmetic substitution is performed, the expression${var: offs}
does work, retrieving the offset from$offs
.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.
$@
or$*
, then offset 0 instead refers to$0
, offset 1 refers to$1
, and so on. In other words, the positional parameter array is effectively extended by prepending$0
. Hence${*:0:1}
substitutes$0
and${*:1:1}
substitutes$1
. -
${``name``/``pattern``/``repl``}
${``name``//``pattern``/``repl``}
${``name``:/``pattern``/``repl``}
Replace the longest possible match ofpattern
in the expansion of parametername
by stringrepl
. The first form replaces just the first occurrence, the second form all occurrences, and the third form replaces only ifpattern
matches the entire string. Bothpattern
andrepl
are subject to double-quoted substitution, so that expressions like${name/$opat/$npat}
will work, but obey the usual rule that pattern characters in$opat
are not treated specially unless either the optionGLOB_SUBST
is set, or$opat
is instead substituted as${~opat}
.The
pattern
may begin with a ‘#
’, in which case thepattern
must match at the start of the string, or ‘%
’, in which case it must match at the end of the string, or ‘#%
’ in which case thepattern
must match the entire string. Therepl
may be an empty string, in which case the final ‘/
’ may also be omitted. To quote the final ‘/
’ in other cases it should be preceded by a single backslash; this is not necessary if the ‘/
’ occurs inside a substituted parameter. Note also that the ‘#
’, ‘%
’ and ‘#%
are not active if they occur inside a substituted parameter, even at the start.If, after quoting rules apply,
${``name``}
expands to an array, the replacements act on each element individually. Note also the effect of theI
andS
parameter expansion flags below; however, the flagsM
,R
,B
,E
andN
are not useful.For example,
foo="twinkle twinkle little star" sub="t*e" rep="spy" print ${foo//${~sub}/$rep} print ${(S)foo//${~sub}/$rep}
Here, the ‘
~
’ ensures that the text of$sub
is treated as a pattern rather than a plain string. In the first case, the longest match fort*e
is substituted and the result is ‘spy star
’, while in the second case, the shortest matches are taken and the result is ‘spy spy lispy star
’. -
${#``spec``}
Ifspec
is one of the above substitutions, substitute the length in characters of the result instead of the result itself. Ifspec
is an array expression, substitute the number of elements of the result. This has the side-effect that joining is skipped even in quoted forms, which may affect other sub-expressions inspec
. Note that ‘^
’, ‘=
’, and ‘~
’, below, must appear to the left of ‘#
’ when these forms are combined.If the option
POSIX_IDENTIFIERS
is not set, andspec
is a simple name, then the braces are optional; this is true even for special parameters so e.g.$#-
and$#*
take the length of the string$-
and the array$*
respectively. IfPOSIX_IDENTIFIERS
is set, then braces are required for the#
to be treated in this fashion. -
${^``spec``}
Turn on the
RC_EXPAND_PARAM
option for the evaluation ofspec
; if the ‘^
’ is doubled, turn it off. When this option is set, array expansions of the formfoo``${``xx``}``bar
, where the parameterxx
is set to(``a b c``)
, are substituted with ‘fooabar foobbar foocbar
’ instead of the default ‘fooa b cbar
’. Note that an empty array will therefore cause all arguments to be removed.Internally, each such expansion is converted into the equivalent list for brace expansion. E.g.,
${^var}
becomes{$var[1],$var[2],
...}
, and is processed as described in Brace Expansion below: note, however, the expansion happens immediately, with any explicit brace expansion happening later. If word splitting is also in effect the$var[``N``]
may themselves be split into different list elements. -
${=``spec``}
Perform word splitting using the rules for
SH_WORD_SPLIT
during the evaluation ofspec
, but regardless of whether the parameter appears in double quotes; if the ‘=
’ is doubled, turn it off. This forces parameter expansions to be split into separate words before substitution, usingIFS
as a delimiter. This is done by default in most other shells.Note that splitting is applied to
word
in the assignment forms ofspec
before the assignment toname
is performed. This affects the result of array assignments with theA
flag. -
${~``spec``}
Turn on the
GLOB_SUBST
option for the evaluation ofspec
; if the ‘~
’ is doubled, turn it off. When this option is set, the string resulting from the expansion will be interpreted as a pattern anywhere that is possible, such as in filename expansion and filename generation and pattern-matching contexts like the right hand side of the ‘=
’ and ‘!=
’ operators in conditions.In nested substitutions, note that the effect of the
~
applies to the result of the current level of substitution. A surrounding pattern operation on the result may cancel it. Hence, for example, if the parameterfoo
is set to*
,${~foo//\*/*.c}
is substituted by the pattern*.c
, which may be expanded by filename generation, but${${~foo}//\*/*.c}
substitutes to the string*.c
, which will not be further expanded.
If a ${
...}
type parameter expression or a $(
...)
type command
substitution is used in place of name
above, it is expanded first and
the result is used as if it were the value of name
. Thus it is
possible to perform nested operations: ${${foo#head}%tail}
substitutes
the value of $foo
with both ‘head
’ and ‘tail
’ deleted. The form
with $(
...)
is often useful in combination with the flags described
next; see the examples below. Each name
or nested ${
...}
in a
parameter expansion may also be followed by a subscript expression as
described in Array Parameters.
Note that double quotes may appear around nested expressions, in which
case only the part inside is treated as quoted; for example,
${(f)"$(foo)"}
quotes the result of $(foo)
, but the flag ‘(f)
’
(see below) is applied using the rules for unquoted expansions. Note
further that quotes are themselves nested in this context; for example,
in "${(@f)"$(foo)"}"
, there are two sets of quotes, one surrounding
the whole expression, the other (redundant) surrounding the $(foo)
as
before.
14.3.1 Parameter Expansion Flags
If the opening brace is directly followed by an opening parenthesis, the
string up to the matching closing parenthesis will be taken as a list of
flags. In cases where repeating a flag is meaningful, the repetitions
need not be consecutive; for example, ‘(q%q%q
)’ means the same thing
as the more readable ‘(%%qqq
)’. The following flags are supported:
-
#
Evaluate the resulting words as numeric expressions and output the characters corresponding to the resulting integer. Note that this form is entirely distinct from use of the#
without parentheses.If the
MULTIBYTE
option is set and the number is greater than 127 (i.e. not an ASCII character) it is treated as a Unicode character. -
%
Expand all%
escapes in the resulting words in the same way as in prompts (see Prompt Expansion). If this flag is given twice, full prompt expansion is done on the resulting words, depending on the setting of thePROMPT_PERCENT
,PROMPT_SUBST
andPROMPT_BANG
options. -
@
In double quotes, array elements are put into separate words. E.g., ‘"${(@)foo}"
’ is equivalent to ‘"${foo[@]}"
’ and ‘"${(@)foo[1,2]}"
’ is the same as ‘"$foo[1]" "$foo[2]"
’. This is distinct from field splitting by thef
,s
orz
flags, which still applies within each array element. -
A
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${${(A``)``name``}[1]}
yields the full value ofname
whenname
is scalar.This assigns an array parameter with ‘
${
...=
...}
’, ‘${
...:=
...}
’ or ‘${
...::=
...}
’. If this flag is repeated (as in ‘AA
’), assigns an associative array parameter. Assignment is made before sorting or padding; if field splitting is active, theword
part is split before assignment. Thename
part may be a subscripted range for ordinary arrays; when assigning an associative array, theword
part must be converted to an array, for example by using ‘${(AA)=``name``=
...}
’ to activate field splitting.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.
-
a
Sort in array index order; when combined with ‘O
’ sort in reverse array index order. Note that ‘a
’ is therefore equivalent to the default but ‘Oa
’ is useful for obtaining an array’s elements in reverse order. -
b
Quote with backslashes only characters that are special to pattern matching. This is useful when the contents of the variable are to be tested usingGLOB_SUBST
, including the${~``...``}
switch.Quoting using one of the
q
family of flags does not work for this purpose since quotes are not stripped from non-pattern characters byGLOB_SUBST
. In other words,pattern=${(q)str} [[ $str = ${~pattern} ]]
works if
$str
is ‘a*b
’ but not if it is ‘a b
’, whereaspattern=${(b)str} [[ $str = ${~pattern} ]]
is always true for any possible value of
$str
. -
c
With${#``name``}
, 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. -
C
Capitalize the resulting words. ‘Words’ in this case refers to sequences of alphanumeric characters separated by non-alphanumerics, not to words that result from field splitting. -
D
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 ‘~
’ substitution: see Filename Expansion. -
e
Perform single word shell expansions, namely parameter expansion, command substitution and arithmetic expansion, on the result. Such expansions can be nested but too deep recursion may have -
f
Split the result of the expansion at newlines. This is a shorthand for ‘ps:\n:
’. -
F
Join the words of arrays together using newline as a separator. This is a shorthand for ‘pj:\n:
’. -
g:``opts``:
Process escape sequences like the echo builtin when no options are given (g::
). With theo
option, octal escapes don’t take a leading zero. With thec
option, sequences like ‘^X
’ are also processed. With thee
option, processes ‘\M-t
’ and similar sequences like the print builtin. With both of theo
ande
options, behaves like the print builtin except that in none of these modes is ‘\c
’ interpreted. -
i
Sort case-insensitively. May be combined with ‘n
’ or ‘O
’. -
k
Ifname
refers to an associative array, substitute the keys (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 theKSH_ARRAYS
option a subscript ‘[*]
’ or ‘[@]
’ is needed to operate on the whole array, as usual. -
L
Convert all letters in the result to lower case. -
n
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 ‘foo1 foo02 foo2 foo3 foo20 foo23
’ is sorted into the order shown. May be combined with ‘i
’ or ‘O
’. -
o
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 ‘a
’, ‘i
’ or ‘n
’. -
O
Sort the resulting words in descending order; ‘O
’ without ‘a
’, ‘i
’ or ‘n
’ sorts in reverse lexical order. May be combined with ‘a
’, ‘i
’ or ‘n
’ to reverse the order of sorting. -
P
This forces the value of the parametername
to be interpreted as a further parameter name, whose value will be used where appropriate. Note that flags set with one of thetypeset
family of commands (in particular case transformations) are not applied to the value ofname
used in this fashion.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 ‘
foo=bar
’ and ‘bar=baz
’, the strings${(P)foo}
,${(P)${foo}}
, and${(P)$(echo bar)}
will be expanded to ‘baz
’.Likewise, if the reference is itself nested, the expression with the flag is treated as if it were directly replaced by the parameter name. It is an error if this nested substitution produces an array with more than one word. For example, if ‘
name=assoc
’ where the parameterassoc
is an associative array, then ‘${${(P)name}[elt]}
’ refers to the element of the associative subscripted ‘elt
’. -
q
Quote characters that are special to the shell in the resulting words with$’\``NNN``’
form, with separate quotes for each octet.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
$
. 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.If a
q-
is given (only a singleq
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.If a
q+
is given, an extended form of minimal quoting is used that This quoting is similar to that used by the output of values by thetypeset
family of commands. -
Q
Remove one level of quotes from the resulting words. -
t
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 (‘-
’). The first keyword in the string describes the main type, it can be one of ‘scalar
’, ‘array
’, ‘integer
’, ‘float
’ or ‘association
’. The other keywords describe the type in more detail:-
local
for local parameters -
left
for left justified parameters -
right_blanks
for right justified parameters with leading blanks -
right_zeros
for right justified parameters with leading zeros -
lower
for parameters whose value is converted to all lower case when it is expanded -
upper
for parameters whose value is converted to all upper case when it is expanded -
readonly
for readonly parameters -
tag
for tagged parameters -
export
for exported parameters -
unique
for arrays which keep only the first occurrence of duplicated values -
hide
for parameters with the ‘hide’ flag -
hideval
for parameters with the ‘hideval’ flag -
special
for special parameters defined by the shell
-
-
u
Expand only the first occurrence of each unique word. -
U
Convert all letters in the result to upper case. -
v
Used withk
, 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. -
V
Make any special characters in the resulting words visible. -
w
With${#``name``}
, count words in arrays or strings; thes
flag may be used to set a word delimiter. -
W
Similar tow
with the difference that empty words between repeated delimiters are also counted. -
X
With this flag, parsing errors occurring with theQ
,e
and#
flags or the pattern matching forms such as ‘${``name``#``pattern``}
’ are reported. Without the flag, errors are silently ignored. -
z
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 theINTERACTIVE_COMMENTS
option unset (however, see theZ
flag below for related options)Note that this is done very late, even later than the ‘
(s)
’ flag. So to access single words in the result use nested expansions as in ‘${${(z)foo}[2]}
’. Likewise, to remove the quotes in the resulting words use ‘${(Q)${(z)foo}}
’. -
0
Split the result of the expansion on null bytes. This is a shorthand for ‘ps:\0:
’.
The following flags (except p
) are followed by one or more arguments
as shown. Any character, or the matching pairs ‘(
...)
’, ‘{
...}
’,
‘[
...]
’, or ‘<
...>
’, 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
Recognize the same escape sequences as theprint
builtin in string arguments to any of the flags described below that follow this argument.Alternatively, with this option string arguments may be in the form
$``var
in which case the value of the variable is substituted. Note this form is strict; the string argument does not undergo general parameter expansion.For example,
sep=: val=a:b:c print ${(ps.$sep.)val}
splits the variable on a
:
. -
~
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~
within the same set of parentheses. Compare with~
outside parentheses, which forces the entire substituted string to be treated as a pattern. Hence, for example,[[ "?" = ${(~j.|.)array} ]]
treats ‘
|
’ as a pattern and succeeds if and only if$array
contains the string ‘?
’ as an element. The~
may be repeated to toggle the behaviour; its effect only lasts to the end of the parenthesised group. -
j:``string``:
Join the words of arrays together usingstring
as a separator. Note that this occurs before field splitting by thes:``string``:
flag or theSH_WORD_SPLIT
option. -
l:``expr``::``string1``::``string2``:
Pad the resulting words on the left. Each word will be truncated if required and placed in a fieldexpr
characters wide.The arguments
:``string1``:
and:``string2``:
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 withstring1
(concatenated as often as needed) or spaces ifstring1
is not given. If bothstring1
andstring2
are given,string2
is inserted once directly to the left of each word, truncated if necessary, beforestring1
is used to produce any remaining padding.If either of
string1
orstring2
is present but empty, i.e. there are two delimiters together at that point, the first character of$IFS
is used instead.If the
MULTIBYTE
option is in effect, the flagm
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.If the
MULTIBYTE
option is not in effect, each byte in the string is treated as occupying one unit of width.Control characters are always assumed to be one unit wide; this allows the mechanism to be used for generating repetitions of control characters.
-
m
Only useful together with one of the flagsl
orr
or with the#
length operator when theMULTIBYTE
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.If the
m
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). -
r:``expr``::``string1``::``string2``:
Asl
, but pad the words on the right and insertstring2
immediately to the right of the string to be padded.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.
-
s:``string``:
Force field splitting at the separatorstring
. Note that astring
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 theIFS
parameter. See also the=
flag and theSH_WORD_SPLIT
option. An empty string may also be given in which case every character will be a separate element.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:
line="one::three" print -l "${(s.:.)line}"
produces two lines of output for
one
andthree
and elides the empty field. To override this behaviour, supply the ‘(@)
’ flag as well, i.e."${(@s.:.)line}"
. -
Z:``opts``:
Asz
but takes a combination of option letters between a following pair of delimiter characters. With no options the effect is identical toz
.(Z+c+)
causes comments to be parsed as a string and retained; any field in the resulting array beginning with an unquoted comment character is a comment.(Z+C+)
causes comments to be parsed and removed. The rule for comments is standard: anything between a word starting with the third character of$HISTCHARS
, default#
, up to the next newline is a comment.(Z+n+)
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.(Z+Cn+)
. -
_:``flags``:
The underscore (_
) flag is reserved for future use. As of this revision of zsh, there are no validflags
; anything following an underscore, other than an empty pair of delimiters, is treated as an error, and the flag itself has no effect.
The following flags are meaningful with the ${
...#
...}
or
${
...%
...}
forms. The S
and I
flags may also be used with the
${
.../
...}
forms.
-
S
With#
or##
, search for the match that starts closest to the start of the string (a ‘substring match’). Of all matches at a particular position,#
selects the shortest and##
the longest:% str="aXbXc" % echo ${(S)str#X*} abXc % echo ${(S)str##X*} a %
With
%
or%%
, search for the match that starts closest to the end of the string:% str="aXbXc" % echo ${(S)str%X*} aXbc % echo ${(S)str%%X*} aXb %
(Note that
%
and%%
don’t search for the match that ends closest to the end of the string, as one might expect.)With substitution via
${
.../
...}
or${
...//
...}
, specifies non-greedy matching, i.e. that the shortest instead of the longest match should be replaced:% str="abab" % echo ${str/*b/_} _ % echo ${(S)str/*b/_} _ab %
-
I:``expr``:
Search theexpr
th match (whereexpr
evaluates to a number). This only applies when searching for substrings, either with theS
flag, or with${
.../
...}
(only theexpr
th match is substituted) or${
...//
...}
(all matches from theexpr
th on are substituted). The default is to take the first match.The
expr
th match is counted such that there is either one or zero matches from each starting position in the string, although for global substitution matches overlapping previous replacements are ignored. With the${
...%
...}
and${
...%%
...}
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.Hence with the string
which switch is the right switch for Ipswich?
substitutions of the form
${
(SI:``N``:
)string#w*ch}
asN
increases from 1 will match and remove ‘which
’, ‘witch
’, ‘witch
’ and ‘wich
’; the form using ‘##
’ will match and remove ‘which switch is the right switch for Ipswich
’, ‘witch is the right switch for Ipswich
’, ‘witch for Ipswich
’ and ‘wich
’. The form using ‘%
’ will remove the same matches as for ‘#
’, but in reverse order, and the form using ‘%%
’ will remove the same matches as for ‘##
’ in reverse order. -
B
Include the index of the beginning of the match in the result. -
E
Include the index one character past the end of the match in the result (note this is inconsistent with other uses of parameter index). -
M
Include the matched portion in the result. -
N
Include the length of the match in the result. -
R
Include the unmatched portion in the result (the Rest).
14.3.2 Rules
Here is a summary of the rules for substitution; this assumes that
braces are present around the substitution, i.e. ${``...``}
. Some
particular examples are given below. Note that the Zsh Development Group
accepts no responsibility for any brain damage which may occur during
the reading of the following rules.
-
1.
Nested substitution
If multiple nested${``...``}
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.Note that, unless the ‘
(P)
’ flag is present, the flags and any subscripts apply directly to the value of the nested substitution; for example, the expansion${${foo}}
behaves exactly the same as${foo}
. When the ‘(P)
’ flag is present in a nested substitution, the other substitution rules are applied to the value before it is interpreted as a name, so${${(P)foo}}
may differ from${(P)foo}
.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
~
and=
). Thus, for example,${${:-=cat}:h}
expands to the directory where thecat
program resides. (Explanation: the internal substitution has no parameter but a default value=cat
, which is expanded by filename expansion to a full path; the outer substitution then applies the modifier:h
and takes the directory part of the path.) -
2.
Internal parameter flags
Any parameter flags set by one of thetypeset
family of commands, in particular the-L
,-R
,-Z
,-u
and-l
options for padding and capitalization, are applied directly to the parameter value. Note these flags are options to the command, e.g. ‘typeset -Z
’; they are not the same as the flags used within parameter substitutions.At the outermost level of substitution, the ‘
(P)
’ flag (rule4.
) 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${${(P)foo}}
form (rule25.
). -
3.
Parameter subscripting
If the value is a raw parameter reference with a subscript, such as${``var``[3]}
, the effect of subscripting is applied directly to the parameter. Subscripts are evaluated left to right; subsequent subscripts apply to the scalar or array value yielded by the previous subscript. Thus ifvar
is an array,${var[1][2]}
is the second character of the first word, but${var[2,4][2]}
is the entire third word (the second word of the range of words two through four of the original array). Any number of subscripts may appear. Flags such as ‘(k)
’ and ‘(v)
’ which alter the result of subscripting are applied. -
4.
Parameter name replacement
At the outermost level of nesting only, the ‘(P)
’ flag is applied. This treats the value so far as a parameter name (which may include a subscript expression) and replaces that with the corresponding value. This replacement occurs later if the ‘(P)
’ flag appears in a nested substitution.If the value so far names a parameter that has internal flags (rule
2.
), those internal flags are applied to the new value after replacement. -
5.
Double-quoted joining
If the value after this process is an array, and the substitution appears in double quotes, and neither an ‘(@)
’ flag nor a ‘#
’ length operator is present at the current level, then words of the value are joined with the first character of the parameter$IFS
, by default a space, between each word (single word arrays are not modified). If the ‘(j)
’ flag is present, that is used for joining instead of$IFS
. -
6.
Nested subscripting
Any remaining subscripts (i.e. of a nested substitution) are evaluated at this point, based on whether the value is an array or a scalar. As with3.
, multiple subscripts can appear. Note that${foo[2,4][2]}
is thus equivalent to${${foo[2,4]}[2]}
and also to"${${(@)foo[2,4]}[2]}"
(the nested substitution returns an array in both cases), but not to"${${foo[2,4]}[2]}"
(the nested substitution returns a scalar because of the quotes). -
7.
Modifiers
Any modifiers, as specified by a trailing ‘#
’, ‘%
’, ‘/
’ (possibly doubled) or by a set of modifiers of the form ‘:...
’ (see Modifiers in History Expansion), are applied to the words of the value at this level. -
8.
Character evaluation
Any ‘(#)
’ flag is applied, evaluating the result so far numerically as a character. -
9.
Length
Any initial ‘#
’ modifier, i.e. in the form${#``var``}
, is used to evaluate the length of the expression so far. -
10.
Forced joining
If the ‘(j)
’ flag is present, or no ‘(j)
’ flag is present but the string is to be split as given by rule11.
, and joining did not take place at rule5.
, any words in the value are joined together using the given string or the first character of$IFS
if none. Note that the ‘(F)
’ flag implicitly supplies a string for joining in this manner. -
11.
Simple word splitting
If one of the ‘(s)
’ or ‘(f)
’ flags are present, or the ‘=
’ specifier was present (e.g.${=``var``}
), the word is split on occurrences of the specified string, or (for=
with neither of the two flags present) any of the characters in$IFS
.If no ‘
(s)
’, ‘(f)
’ or ‘=
’ was given, but the word is not quoted and the optionSH_WORD_SPLIT
is set, the word is split on occurrences of any of the characters in$IFS
. Note this step, too, takes place at all levels of a nested substitution. -
12.
Case modification
Any case modification from one of the flags ‘(L)
’, ‘(U)
’ or ‘(C)
’ is applied. -
13.
Escape sequence replacement
First any replacements from the ‘(g)
’ flag are performed, then any prompt-style formatting from the ‘(%)
’ family of flags is applied. -
14.
Quote application
Any quoting or unquoting using ‘(q)
’ and ‘(Q)
’ and related flags is applied. -
15.
Directory naming
Any directory name substitution using ‘(D)
’ flag is applied. -
16.
Visibility enhancement
Any modifications to make characters visible using the ‘(V)
’ flag are applied. -
17.
Lexical word splitting
If the ’(z)
’ flag or one of the forms of the ’(Z)
’ flag is present, the word is split as if it were a shell command line, so that quotation marks and other metacharacters are used to decide what constitutes a word. Note this form of splitting is entirely distinct from that described by rule11.
: it does not use$IFS
, and does not cause forced joining. -
18.
Uniqueness
If the result is an array and the ‘(u)
’ flag was present, duplicate elements are removed from the array. -
19.
Ordering
If the result is still an array and one of the ‘(o)
’ or ‘(O)
’ flags was present, the array is reordered. -
20.
RC_EXPAND_PARAM
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 theRC_EXPAND_PARAM
option or the ‘^
’ flag. -
21.
Re-evaluation
Any ‘(e)
’ flag is applied to the value, forcing it to be re-examined for new parameter substitutions, but also for command and arithmetic substitutions. -
22.
Padding
Any padding of the value by the ‘(l.``fill``.)
’ or ‘(r.``fill``.)
’ flags is applied. -
23.
Semantic joining
In contexts where expansion semantics requires a single word to result, all words are rejoined with the first character ofIFS
between. So in ‘${(P``)${(f``)lines}}
’ the value of${lines}
is split at newlines, but then must be joined again before the ‘(P)
’ flag can be applied.If a single word is not required, this rule is skipped.
-
24.
Empty argument removal
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.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.
-
25.
Nested parameter name replacement
If the ‘(P)
’ flag is present and rule4.
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 (rule2.
) applied to the new value.
14.3.3 Examples
The flag f
is useful to split a double-quoted substitution line by
line. For example, ${(f)"$(<``file``)"}
substitutes the contents of
file
divided so that each line is an element of the resulting array.
Compare this with the effect of $``(<``file``)
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.
The following illustrates the rules for nested parameter expansions.
Suppose that $foo
contains the array (bar baz``)
:
-
"${(@)${foo}[1]}"
This produces the resultb
. First, the inner substitution"${foo}"
, which has no array (@
) flag, produces a single word result"bar baz"
. The outer substitution"${(@)...[1]}"
detects that this is a scalar, so that (despite the ‘(@)
’ flag) the subscript picks the first character. -
"${${(@)foo}[1]}"
This produces the result ‘bar
’. In this case, the inner substitution"${(@)foo}"
produces the array ‘(bar baz``)
’. The outer substitution"${...[1]}"
detects that this is an array and picks the first word. This is similar to the simple case"${foo[1]}"
.
As an example of the rules for word splitting and joining, suppose
$foo
contains the array ‘(ax1 bx1``)
’. Then
-
${(s/x/)foo}
produces the words ‘a
’, ‘1 b
’ and ‘1
’. -
${(j/x/s/x/)foo}
produces ‘a
’, ‘1
’, ‘b
’ and ‘1
’. -
${(s/x/)foo%%1*}
produces ‘a
’ and ‘b
’ (note the extra space). As substitution occurs before either joining or splitting, the operation first generates the modified array(ax bx``)
, which is joined to give"ax bx"
, and then split to give ‘a
’, ‘b
’ and ‘’. The final empty string will then be elided, as it is not in double quotes.
14.4 Command Substitution
A command enclosed in parentheses preceded by a dollar sign, like
‘$(
...)
’, or quoted with grave accents, like ‘‘
...‘
’, 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 IFS
parameter.
The substitution ‘$(cat
foo``)
’ may be replaced by the faster
‘$(<``foo``)
’. In this case foo
undergoes single word shell
expansions (parameter expansion, command substitution and
arithmetic expansion), but not filename generation.
If the option GLOB_SUBST
is set, the result of any unquoted command
substitution, including the special form just mentioned, is eligible for
filename generation.
14.5 Arithmetic Expansion
A string of the form ‘$[``exp``]
’ or ‘$((``exp``))
’ is substituted
with the value of the arithmetic expression exp
. exp
is subjected to
parameter expansion, command substitution and arithmetic expansion
before it is evaluated. See Arithmetic
Evaluation.
14.6 Brace Expansion
A string of the form ‘foo``{``xx``,``yy``,``zz``}``bar
’ is expanded to
the individual words ‘fooxxbar
’, ‘fooyybar
’ and ‘foozzbar
’.
Left-to-right order is preserved. This construct may be nested. Commas
may be quoted in order to include them literally in a word.
An expression of the form ‘{``n1``..``n2``}
’, where n1
and n2
are
integers, is expanded to every number between n1
and n2
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 -
character is also included in the width. If the numbers
are in decreasing order the resulting sequence will also be in
decreasing order.
An expression of the form ‘{``n1``..``n2``..``n3``}
’, where n1
,
n2
, and n3
are integers, is expanded as above, but only every n3
th
number starting from n1
is output. If n3
is negative the numbers are
output in reverse order, this is slightly different from simply swapping
n1
and n2
in the case that the step n3
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
‘{-99..100..01}
’ which is not possible to specify by putting a 0 on
either of the first two numbers (i.e. pad to two characters).
An expression of the form ‘{``c1``..``c2``}
’, where c1
and c2
are
single characters (which may be multibyte characters), is expanded to
every character in the range from c1
to c2
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. ‘{d..a}
’ is substituted as ‘d c b a
’.
If a brace expression matches none of the above forms, it is left
unchanged, unless the option BRACE_CCL
(an abbreviation for ‘brace
character class’) is set.
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 [
...]
expression in filename generation: ‘-
’ is treated
specially to denote a range of characters, but ‘^
’ or ‘!
’ as the
first character is treated normally. For example, ‘{abcdef0-9}
’
expands to 16 words 0 1 2 3 4 5 6 7 8 9 a b c d e f
.
Note that brace expansion is not part of filename generation (globbing);
an expression such as */{foo,bar}
is split into two separate words
*/foo
and */bar
before filename generation takes place. In
particular, note that this is liable to produce a ‘no match’ error if
either of the two expressions does not match; this is to be contrasted
with */(foo|bar)
, which is treated as a single pattern but otherwise
has similar effects.
To combine brace expansion with array expansion, see the ${^``spec``}
form described in Parameter Expansion above.
14.7 Filename Expansion
Each word is checked to see if it begins with an unquoted ‘~
’. If it
does, then the word up to a ‘/
’, or the end of the word if there is no
‘/
’, is checked to see if it can be substituted in one of the ways
described here. If so, then the ‘~
’ and the checked portion are
replaced with the appropriate substitute value.
A ‘~
’ by itself is replaced by the value of $HOME
. A ‘~
’ followed
by a ‘+
’ or a ‘-
’ is replaced by current or previous working
directory, respectively.
A ‘~
’ followed by a number is replaced by the directory at that
position in the directory stack. ‘~0
’ is equivalent to ‘~+
’, and
‘~1
’ is the top of the stack. ‘~+
’ followed by a number is
replaced by the directory at that position in the directory stack.
‘~+0
’ is equivalent to ‘~+
’, and ‘~+1
’ is the top of the stack.
‘~-
’ followed by a number is replaced by the directory that many
positions from the bottom of the stack. ‘~-0
’ is the bottom of the
stack. The
PUSHD_MINUS
option exchanges the effects of ‘~+
’ and ‘~-
’ where
they are followed by a number.
14.7.1 Dynamic named directories
If the function zsh_directory_name
exists, or the shell variable
zsh_directory_name_functions
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.
A ‘~
’ followed by a string namstr
in unquoted square brackets is
treated specially as a dynamic directory name. Note that the first
unquoted closing square bracket always terminates namstr
. The shell
function is passed two arguments: the string n
(for name) and
namstr
. It should either set the array reply
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 NOMATCH
is
set, an error results.
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 %~
in prompts. In this case each function is passed two
arguments: the string d
(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 ‘~[``...``]
’), and the second is the
prefix length of the directory to be replaced. For example, if the trial
directory is /home/myname/src/zsh
and the dynamic name for
/home/myname/src
(which has 16 characters) is s
, then the function
sets
reply=(s 16)
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.
It is not a requirement that a function implements both n
and d
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 d
should cause a non-zero status to be returned.
The completion system calls ‘zsh_directory_name c
’ followed by
equivalent calls to elements of the array
zsh_directory_name_functions
, 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 Completion
System.
As a working example, here is a function that expands any dynamic names
beginning with the string p:
to directories below
/home/pws/perforce
. In this simple case a static name for the
directory would be just as effective.
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
[[ $2 != (#b)p:(?*) ]] && return 1
typeset -ga reply
reply=(/home/pws/perforce/$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
}
14.7.2 Static named directories
A ‘~
’ followed by anything not already covered consisting of any
number of alphanumeric characters or underscore (‘_
’), hyphen (‘-
’),
or dot (‘.
’) 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 ‘~
’ is the name of a string shell parameter whose
value begins with a ‘/
’. Note that trailing slashes will be removed
from the path to the directory (though the original parameter is not
modified).
It is also possible to define directory names using the -d
option to
the hash
builtin.
When the shell prints a path (e.g. when expanding %~
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 ‘~
’ 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 $PWD
and $OLDPWD
are never abbreviated in
this fashion.
14.7.3 ‘=’ expansion
If a word begins with an unquoted ‘=
’ and the EQUALS
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.
14.7.4 Notes
Filename expansion is performed on the right hand side of a parameter
assignment, including those appearing after commands of the typeset
family. In this case, the right hand side will be treated as a
colon-separated list in the manner of the PATH
parameter, so that a
‘~
’ or an ‘=
’ following a ‘:
’ is eligible for expansion. All
such behaviour can be disabled by quoting the ‘~
’, the ‘=
’, or the
whole expression (but not simply the colon); the EQUALS
option is also
respected.
If the option MAGIC_EQUAL_SUBST
is set, any unquoted shell argument in
the form ‘identifier``=``expression
’ becomes eligible for file
expansion as described in the previous paragraph. Quoting the first
‘=
’ also inhibits this.
14.8 Filename Generation
If a word contains an unquoted instance of one of the characters ‘*
’,
‘(
’, ‘|
’, ‘<
’, ‘[
’, or ‘?
’, it is regarded as a pattern for
filename generation, unless the GLOB
option is unset.
If the EXTENDED_GLOB
option
is set, the ‘^
’
and ‘#
’ characters also denote a pattern; otherwise they are not
treated specially by the shell.
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 NULL_GLOB
option is set,
in which case the
word is deleted; or unless the NOMATCH
option is unset, in which case
the word is left unchanged.
In filename generation, the character ‘/
’ must be matched explicitly;
also, a ‘.
’ must be matched explicitly at the beginning of a pattern
or after a ‘/
’, unless the GLOB_DOTS
option is set.
No filename
generation pattern matches the files ‘.
’ or ‘..
’. In other instances
of pattern matching, the ‘/
’ and ‘.
’ are not treated specially.
14.8.1 Glob Operators
-
*
Matches any string, including the null string. -
?
Matches any character. -
[
...]
Matches any of the enclosed characters. Ranges of characters can be specified by separating two characters by a ‘-
’. A ‘-
’ or ‘]
’ may be matched by including it as the first character in the list. There are also several named classes of characters, in the form ‘[:``name``:]
’ 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):-
[:alnum:]
The character is alphanumeric -
[:alpha:]
The character is alphabetic -
[:ascii:]
The character is 7-bit, i.e. is a single-byte character without the top bit set. -
[:blank:]
The character is a blank character -
[:cntrl:]
The character is a control character -
[:digit:]
The character is a decimal digit -
[:graph:]
[:lower:]
The character is a lowercase letter -
[:print:]
[:punct:]
[:space:]
The character is whitespace -
[:upper:]
The character is an uppercase letter -
[:xdigit:]
The character is a hexadecimal digit
Another set of named classes is handled internally by the shell and is not sensitive to the locale:
-
[:IDENT:]
The character is allowed to form part of a shell identifier, such as a parameter name -
[:IFS:]
The character is used as an input field separator, i.e. is contained in theIFS
parameter -
[:IFSSPACE:]
The character is an IFS white space character; see the documentation forIFS
in Parameters Used By The Shell. -
[:INCOMPLETE:]
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 ‘[[:INCOMPLETE:]]*
’. This will never match a sequence starting with a valid multibyte character. -
[:INVALID:]
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. -
[:WORD:]
The character is treated as part of a word; this test is sensitive to the value of theWORDCHARS
parameter
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 ‘
[[:alnum:]]
’. Named character sets can be used alongside other types, e.g. ‘[[:alpha:]0-9]
’. -
-
[^
...]
[!
...]
Like[
...]
, except that it matches any character which is not in the given set. -
<
[x
]-
[y
]>
Matches any number in the rangex
toy
, inclusive. Either of the numbers may be omitted to make the range open-ended; hence ‘<->
’ matches any number. To match individual digits, the[
...]
form is more efficient.Be careful when using other wildcards adjacent to patterns of this form; for example,
<0-9>*
will actually match any number whatsoever at the start of the string, since the ‘<0-9>
’ will match the first digit, and the ‘*
’ will match any others. This is a trap for the unwary, but is match always succeeds. Expressions such as ‘<0-9>[^[:digit:]]*
’ can be used instead. -
(
...)
Matches the enclosed pattern. This is used for grouping. If theKSH_GLOB
option is set, then a ‘@
’, ‘*
’, ‘+
’, ‘?
’ or ‘!
’ immediately preceding the ‘(
’ is treated specially, as detailed below. The optionSH_GLOB
prevents bare parentheses from being used in this way, though theKSH_GLOB
option is still available.Note that grouping cannot extend over multiple directories: it is an error to have a ‘
/
’ within a group (this only applies for patterns used in filename generation). There is one exception: a group of the form(``pat``/)#
appearing as a complete path segment can match a sequence of directories. For example,foo/(a*/)#bar
matchesfoo/bar
,foo/any/bar
,foo/any/anyother/bar
, and so on. -
x``|``y
Matches eitherx
ory
. This operator has lower precedence than any other. The ‘|
’ character must be within parentheses, to avoid interpretation as a pipeline. The alternatives are tried in order from left to right. -
^``x
(RequiresEXTENDED_GLOB
to be set.) Matches anything except the patternx
. This has a higher precedence than ‘/
’, so ‘^foo/bar
’ will search directories in ‘.
’ except ‘./foo
’ for a file named ‘bar
’. -
x``~``y
(RequiresEXTENDED_GLOB
to be set.) Match anything that matches the patternx
but does not matchy
. This has lower precedence than any operator except ‘|
’, so ‘*/*~foo/bar
’ will search for all files in all directories in ‘.
’ and then exclude ‘foo/bar
’ if there was such a match. Multiple patterns can be excluded by ‘foo``~``bar``~``baz
’. In the exclusion pattern (y
), ‘/
’ and ‘.
’ are not treated specially the way they usually are in globbing. -
x``#
(RequiresEXTENDED_GLOB
to be set.) Matches zero or more occurrences of the patternx
. This operator has high precedence; ‘12#
’ is equivalent to ‘1(2#)
’, rather than ‘(12)#
’. It is an error for an unquoted ‘#
’ to follow something which cannot be repeated; this includes an empty string, a pattern already followed by ‘##
’, or parentheses when part of aKSH_GLOB
pattern (for example, ‘!(``foo``)#
’ is invalid and must be replaced by ‘*(!(``foo``))
’). -
x``##
(RequiresEXTENDED_GLOB
to be set.) Matches one or more occurrences of the patternx
. This operator has high precedence; ‘12##
’ is equivalent to ‘1(2##)
’, rather than ‘(12)##
’. No more than two active ‘#
’ characters may appear together. (Note the potential clash with glob qualifiers in the form ‘1(2##)
’ which should therefore be avoided.)
14.8.2 ksh-like Glob Operators
If the KSH_GLOB
option is set, the effects of parentheses can be
modified by a preceding ‘@
’, ‘*
’, ‘+
’, ‘?
’ or ‘!
’. This
character need not be unquoted to have special effects, but the ‘(
’
must be.
-
@(
...)
Match the pattern in the parentheses. (Like ‘(
...)
’.) -
*(
...)
Match any number of occurrences. (Like ‘(
...)#
’, except that recursive directory searching is not supported.) -
+(
...)
Match at least one occurrence. (Like ‘(
...)##
’, except that recursive directory searching is not supported.) -
?(
...)
Match zero or one occurrence. (Like ‘(|
...)
’.) -
!(
...)
Match anything but the expression in parentheses. (Like ‘(^(
...))
’.)
14.8.3 Precedence
The precedence of the operators given above is (highest) ‘^
’, ‘/
’,
‘~
’, ‘|
’ (lowest); the remaining operators are simply treated from
left to right as part of a string, with ‘#
’ and ‘##
’ applying to the
shortest possible preceding unit (i.e. a character, ‘?
’, ‘[
...]
’,
‘<
...>
’, or a parenthesised expression). As mentioned above, a
‘/
’ used as a directory separator may not appear inside parentheses,
while a ‘|
’ must do so; in patterns used in other contexts than
filename generation (for example, in case
statements and tests within
‘[[
...]]
’), a ‘/
’ is not special; and ‘/
’ is also not special
after a ‘~
’ appearing outside parentheses in a filename pattern.
14.8.4 Globbing Flags
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 EXTENDED_GLOB
option. All take the form (#``X``)
where X
may
have one of the following forms:
-
i
Case insensitive: upper or lower case characters in the pattern match upper or lower case characters. -
l
Lower case characters in the pattern match upper or lower case characters; upper case characters in the pattern still only match upper case characters. -
I
Case sensitive: locally negates the effect ofi
orl
from that point on. -
b
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$match
, the indices of the beginning of the matched parentheses in the array$mbegin
, and the indices of the end in the array$mend
, 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$mend
and$mbegin
may be used in subscripts; theKSH_ARRAYS
option is respected. Sets of globbing flags are not considered parenthesised groups; only the first nine active parentheses can be referenced.For example,
foo="a_string_with_a_message" if [[ $foo = (a|an)_(#b)(*) ]]; then print ${foo[$mbegin[1],$mend[1]]} fi
prints ‘
string_with_a_message
’. Note that the first set of parentheses is before the(#b)
and does not create a backreference.Backreferences work with all forms of pattern matching other than filename generation, but note that when performing matches on an entire array, such as
${``array``#``pattern``}
, or a global substitution, such as${``param``//``pat``/``repl``}
, only the data for the last match remains available. In the case of global replacements this may still be useful. See the example for them
flag below.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 ‘
#
’ or ‘##
’. Only the last match of the parenthesis is remembered: for example, in ‘[[ abab = (#b)([ab])# ]]
’, only the final ‘b
’ is stored inmatch[1]
. Thus extra parentheses may be necessary to match the complete segment: for example, use ‘X((ab|cd)#)Y
’ to match a whole string of either ‘ab
’ or ‘cd
’ between ‘X
’ and ‘Y
’, using the value of$match[1]
rather than$match[2]
.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
#
and matched zero times — then the matched string is set to the empty string, and the start and end indices are set to -1.Pattern matching with backreferences is slightly slower than without.
-
B
Deactivate backreferences, negating the effect of theb
flag from that point on. -
c``N``,``M
The flag(#c``N``,``M``)
can be used anywhere that the#
or##
operators can be used except in the expressions ‘(*/)#
’ and ‘(*/)##
’ in filename generation, where ‘/
’ 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{``N``,``M``}
in regular expressions. The previous character or group is required to match betweenN
andM
times, inclusive. The form(#c``N``)
requires exactlyN
matches;(#c,``M``)
is equivalent to specifyingN
as 0;(#c``N``,)
specifies that there is no maximum limit on the number of matches. -
m
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$MATCH
,$MBEGIN
and$MEND
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.For example,
arr=(veldt jynx grimps waqf zho buck) print ${arr//(#m)[aeiou]/${(U)MATCH}}
forces all the matches (i.e. all vowels) into uppercase, printing ‘
vEldt jynx grImps wAqf zhO bUck
’.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.
-
M
Deactivate them
flag, hence no references to match data will be created. -
a``num
Approximate matching:num
errors are allowed in the string matched by the pattern. The rules for this are described in the next subsection. -
s
,e
Unlike the other flags, these have only a local effect, and each must appear on its own: ‘(#s)
’ and ‘(#e)
’ are the only valid forms. The ‘(#s)
’ flag succeeds only at the start of the test string, and the ‘(#e)
’ flag succeeds only at the end of the test string; they correspond to ‘^
’ and ‘$
’ 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, ‘*((#s)|/)test((#e)|/)*
’ matches a path segment ‘test
’ in any of the following strings:test
,test/at/start
,at/end/test
,in/test/middle
.Another use is in parameter substitution; for example ‘
${array/(#s)A*Z(#e)}
’ will remove only elements of an array which match the complete pattern ‘A*Z
’. There are other ways of performing many operations of this type, however the combination of the substitution operations ‘/
’ and ‘//
’ with the ‘(#s)
’ and ‘(#e)
’ flags provides a single simple and memorable method.Note that assertions of the form ‘
(^(#s))
’ 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 ‘(""~(#s))
’ to match a zero-length portion of the string not at the start. -
q
A ‘q
’ 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 ‘(#b)(*).c(#q.)
’ can be used both for globbing and for matching against a string. In the former case, the ‘(#q.)
’ will be treated as a glob qualifier and the ‘(#b)
’ will not be useful, while in the latter case the ‘(#b)
’ is useful for backreferences and the ‘(#q.)
’ will be ignored. Note that colon modifiers in the glob qualifiers are also not applied in ordinary pattern matching. -
u
Respect the current locale in determining the presence of multibyte characters in a pattern, provided the shell was compiled withMULTIBYTE_SUPPORT
. This overrides theMULTIBYTE
option; the default behaviour is taken from the option. CompareU
. (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.) -
U
All characters are considered to be a single byte long. The opposite ofu
. This overrides theMULTIBYTE
option.
For example, the test string fooxx
can be matched by the pattern
(#i``)FOOXX
, but not by (#l``)FOOXX
, (#i``)FOO``(#I``)XX
or
((#i``)FOOX``)X
. The string (#ia2``)readme
specifies
case-insensitive matching of readme
with up to two errors.
When using the ksh syntax for grouping both KSH_GLOB
and
EXTENDED_GLOB
must be set and the left parenthesis should be preceded
by @
. Note also that the flags do not affect letters inside [
...]
groups, in other words (#i``)[a-z]
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 (#i``)/foo/bar/...
is potentially
slow.
14.8.5 Approximate Matching
When matching approximately, the shell keeps a count of the errors
found, which cannot exceed the number specified in the (#a``num``)
flags. Four types of error are recognised:
-
1.
Different characters, as infooxbar
andfooybar
. -
2.
Transposition of characters, as inbanana
andabnana
. -
3.
A character missing in the target string, as with the patternroad
and target stringrod
. -
4.
An extra character appearing in the target string, as withstove
andstrove
.
Thus, the pattern (#a3``)abcd
matches dcba
, with the errors
occurring by using the first rule twice and the second once, grouping
the string as [d][cb][a]
and [a][bc][d]
.
Non-literal parts of the pattern must match exactly, including
characters in character ranges: hence (#a1``)???
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 ?
must match. Other characters
which must match exactly are initial dots in filenames (unless the
GLOB_DOTS
option is set), and all slashes in filenames, so that a/bc
is two errors from ab/c
(the slash cannot be transposed with another
character). Similarly, errors are counted separately for non-contiguous
strings in the pattern, so that (ab|cd``)ef
is two errors from aebf
.
When using exclusion via the ~
operator, approximate matching is
treated entirely separately for the excluded part and must be activated
separately. Thus, (#a1``)README~READ_ME
matches READ.ME
but not
READ_ME
, as the trailing READ_ME
is matched without approximation.
However, (#a1``)README~(#a1``)READ_ME
does not match any pattern of
the form READ``?``ME
as all such forms are now excluded.
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, (#a1``)cat``((#a0``)dog``)fox
allows one error in total, which may not occur in the dog
section, and
the pattern (#a1``)cat``(#a0``)dog``(#a1``)fox
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,
(#a1)abc(#a0)xyz
will not match abcdxyz
, because the error occurs at
the ‘x
’, where approximation is turned off.
Entire path segments may be matched approximately, so that
‘(#a1)/foo/d/is/available/at/the/bar
’ allows one error in any path
segment. This is much less efficient than without the (#a1)
, however,
since every directory in the path must be scanned for a possible
approximate match. It is best to place the (#a1)
after any path
segments which are known to be correct.
14.8.6 Recursive Globbing
A pathname component of the form ‘(``foo``/)#
’ matches a path
consisting of zero or more directories matching the pattern foo
.
As a shorthand, ‘**/
’ is equivalent to ‘(*/)#
’; note that this
therefore matches files in the current directory as well as
subdirectories. Thus:
ls -ld -- (*/)#bar
or
ls -ld -- **/bar
does a recursive directory search for files named ‘bar
’ (potentially
including the file ‘bar
’ in the current directory). This form does not
follow symbolic links; the alternative form ‘***/
’ 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 ‘*
’
operators revert to their usual effect.
Even shorter forms are available when the option GLOB_STAR_SHORT
is
set. In that case if no /
immediately follows a **
or ***
they are
treated as if both a /
plus a further *
are present. Hence:
setopt GLOBSTARSHORT
ls -ld -- **.c
is equivalent to
ls -ld -- **/*.c
14.8.7 Glob Qualifiers
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.
If the option BARE_GLOB_QUAL
is set, then a trailing set of
parentheses containing no ‘|
’ or ‘(
’ characters (or ‘~
’ 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 ‘(^x)
’, can be
forced to be treated as part of the glob pattern by doubling the
parentheses, in this case producing ‘((^x))
’.
If the option EXTENDED_GLOB
is set, a different syntax for glob
qualifiers is available, namely ‘(#q``x``)
’ where x
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 ‘|
’, ‘(
’
or ‘~
’ 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 ‘[[
’ form the presence of a parenthesised expression (#q``...``)
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 (#q)
. This does not apply to the right hand side of pattern
match operators as the syntax already has special significance.
A qualifier may be any one of the following:
-
/
directories -
F
‘full’ (i.e. non-empty) directories. Note that the opposite sense(^F``)
expands to empty directories and all non-directories. Use(/^F``)
for empty directories. -
.
plain files -
@
symbolic links -
=
sockets -
p
named pipes (FIFOs) -
*
%
device files (character or block special) -
%b
block special files -
%c
character special files -
r
owner-readable files (0400) -
w
x
A
group-readable files (0040) -
I
E
R
world-readable files (0004) -
W
X
s
setuid files (04000) -
S
setgid files (02000) -
t
files with the sticky bit (01000) -
f``spec
files with access rights matchingspec
. Thisspec
may be a octal number optionally preceded by a ‘=
’, a ‘+
’, or a ‘-
’. If none of these characters is given, the behavior is the same as for ‘=
’. The octal number describes the mode bits to be expected, if combined with a ‘=
’, the value given must match the file-modes exactly, with a ‘+
’, at least the bits in the given number must be set in the file-modes, and with a ‘-
’, the bits in the number must not be set. Giving a ‘?
’ 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 ‘=
’.If the qualifier ‘
f
’ is followed by any other character anything up to the next matching character (‘[
’, ‘{
’, and ‘<
’ match ‘]
’, ‘}
’, and ‘>
’ respectively, any other character matches itself) is taken as a list of comma-separatedsub-spec
s. Eachsub-spec
may be either an octal number as described above or a list of any of the characters ‘u
’, ‘g
’, ‘o
’, and ‘a
’, followed by a ‘=
’, a ‘+
’, or a ‘-
’, followed by a list of any of the characters ‘r
’, ‘w
’, ‘x
’, ‘s
’, and ‘t
’, or an octal digit. The first list of characters specify which access rights are to be checked. If a ‘u
’ is given, those for the owner of the file are used, if a ‘g
’ is given, those of the group are checked, a ‘o
’ means to test those of other users, and the ‘a
’ says to test all three groups. The ‘=
’, ‘+
’, and ‘-
’ 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: ‘r
’ for read access, ‘w
’ for write access, ‘x
’ for the right to execute the file (or to search a directory), ‘s
’ for the setuid and setgid bits, and ‘t
’ for the sticky bit.Thus, ‘
*(f70?)
’ 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 ‘*(f-100)
’ gives all files for which the owner does not have execute permission, and ‘*(f:gu+w,o-rx:)
’ 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. -
e``string
+``cmd
Thestring
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).In the first form, the first character after the ‘
e
’ will be used as a separator and anything up to the next matching separator will be taken as thestring
; ‘[
’, ‘{
’, and ‘<
’ match ‘]
’, ‘}
’, and ‘>
’, respectively, while any other character matches itself. Note that expansions must be quoted in thestring
to prevent them from being expanded before globbing is done.string
is then executed as shell code. The stringglobqual
is appended to the arrayzsh_eval_context
the duration of execution.During the execution of
string
the filename currently being tested is available in the parameterREPLY
; the parameter may be altered to a string to be inserted into the list instead of the original filename. In addition, the parameterreply
may be set to an array or a string, which overrides the value ofREPLY
. If set to an array, the latter is inserted into the command line word by word.For example, suppose a directory contains a single file ‘
lonely
’. Then the expression ‘*(e:’reply=(${REPLY}{1,2})’:)
’ will cause the words ‘lonely1
’ and ‘lonely2
’ to be inserted into the command line. Note the quoting ofstring
.The form
+``cmd
has the same effect, but no delimiters appear aroundcmd
. Instead,cmd
is taken as the longest sequence of characters following the+
that are alphanumeric or underscore. Typicallycmd
will be the name of a shell function that contains the appropriate test. For example,nt() { [[ $REPLY -nt $NTREF ]] } NTREF=reffile ls -ld -- *(+nt)
lists all files in the directory that have been modified more recently than
reffile
. -
d``dev
files on the devicedev
-
l
[-
|+
]ct
files having a link count less thanct
(-
), greater thanct
(+
), or equal toct
-
U
files owned by the effective user ID -
G
files owned by the effective group ID -
u``id
files owned by user IDid
if that is a number. Otherwise,id
specifies a user name: the character after the ‘u
’ 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 ‘[
’, ‘{
’, and ‘<
’ match the final separators ‘]
’, ‘}
’, and ‘>
’, respectively; any other character matches itself. The selected files are those owned by this user. For example, ‘u:foo:
’ or ‘u[foo]
’ selects files owned by user ‘foo
’. -
g``id
likeu``id
but with group IDs or names -
a
[Mwhms
][-
|+
]n
files accessed exactlyn
days ago. Files accessed within the lastn
days are selected using a negative value forn
(-``n
). Files accessed more thann
days ago are selected by a positiven
value (+``n
). Optional unit specifiers ‘M
’, ‘w
’, ‘h
’, ‘m
’ or ‘s
’ (e.g. ‘ah5
’) cause the check to be performed with months (of 30 days), weeks, hours, minutes or seconds instead of days, respectively. An explicit ‘d
’ for days is also allowed.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, ‘
echo *(ah-5)
’ would echo files accessed within the last five hours, while ‘echo *(ah+5)
’ would echo files accessed at least six hours ago, as times strictly between five and six hours are treated as five hours. -
m
[Mwhms
][-
|+
]n
like the file access qualifier, except that it uses the file modification time. -
c
[Mwhms
][-
|+
]n
like the file access qualifier, except that it uses the file inode change time. -
L
[+
|-
]n
files less thann
bytes (-
), more thann
bytes (+
), or exactlyn
bytes in length.If this flag is directly followed by a size specifier ‘
k
’ (‘K
’), ‘m
’ (‘M
’), or ‘p
’ (‘P
’) (e.g. ‘Lk-50
’) the check is performed with kilobytes, megabytes, or blocks (of 512 bytes) instead. (On some systems additional specifiers are available for gigabytes, ‘g
’ or ‘G
’, and terabytes, ‘t
’ or ‘T
’.) If a size specifier is used a file is regarded as "exactly" the size if the file size rounded up to the next unit is equal to the test size. Hence ‘*(Lm1)
’ matches files from 1 byte up to 1 Megabyte inclusive. Note also that the set of files "less than" the test size only includes files that would not match the equality test; hence ‘*(Lm-1)
’ only matches files of zero size. -
^
negates all qualifiers following it -
-
toggles between making the qualifiers work on symbolic links (the default) and the files they point to -
M
sets theMARK_DIRS
option for the current pattern -
T
appends a trailing qualifier mark to the filenames, analogous to theLIST_TYPES
option, for the current pattern (overridesM
) -
N
sets theNULL_GLOB
option for the current pattern -
D
sets theGLOB_DOTS
option for the current pattern -
n
sets theNUMERIC_GLOB_SORT
option for the current pattern -
Y``n
enables short-circuit mode: the pattern will expand to at mostn
filenames. If more thann
matches exist, only the firstn
matches in directory traversal order will be considered.Implies
oN
when noo``c
qualifier is used. -
o``c
specifies how the names of the files should be sorted. Ifc
isn
they are sorted by name; if it isL
they are sorted depending on the size (length) of the files; ifl
they are sorted by the number of links; ifa
,m
, orc
they are sorted by the time of the last access, modification, or inode change respectively; ifd
, 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 ‘odon
’ to sort on names for files within the same directory; ifN
, no sorting is performed. Note thata
,m
, andc
compare the age against the current time, hence the first name in the list is the youngest file. Also note that the modifiers^
and-
are used, so ‘*(^-oL)
’ gives a list of all files sorted by file size in descending order, following any symbolic links. UnlessoN
is used, multiple order specifiers may occur to resolve ties.The default sorting is
n
(by name) unless theY
glob qualifier is used, in which case it isN
(unsorted).oe
ando+
are special cases; they are each followed by shell code, delimited as for thee
glob qualifier and the+
glob qualifier respectively (see above). The code is executed for each matched file with the parameterREPLY
set to the name of the file on entry andglobsort
appended tozsh_eval_context
. The code should modify the parameterREPLY
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,oe
ando+
may be repeated, but note that the maximum number of sort operators of any kind that may appear in any glob expression is 12. -
O``c
like ‘o
’, but sorts in descending order; i.e. ‘*(^oc)
’ is the same as ‘*(Oc)
’ and ‘*(^Oc)
’ is the same as ‘*(oc)
’; ‘Od
’ puts files in the current directory before those in subdirectories at each level of the search. -
[``beg
[,``end
]]
specifies which of the matched filenames should be included in the returned list. The syntax is the same as for array subscripts.beg
and the optionalend
may be mathematical expressions. As in parameter subscripting they may be negative to make them count from the last match backward. E.g.: ‘*(-OL[1,3])
’ gives a list of the names of the three largest files. -
P``string
Thestring
will be prepended to each glob match as a separate word.string
is delimited in the same way as arguments to thee
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.A typical use for this is to prepend an option before all occurrences of a file name; for example, the pattern ‘
*(P:-f:)
’ produces the command line arguments ‘-f
file1
-f
file2
...’If the modifier
^
is active, thenstring
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 ‘*(P:foo:^P:bar:^P:baz:)
’ which produces the command line arguments ‘foo
baz
file1
bar
...’
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 ‘M
’, ‘T
’,
‘N
’, ‘D
’, ‘n
’, ‘o
’, ‘O
’ and the subscripts given in brackets
(‘[``...``]
’).
If a ‘:
’ appears in a qualifier list, the remainder of the expression
in parenthesis is interpreted as a modifier (see Modifiers
in History Expansion). Each modifier must be
introduced by a separate ‘:
’. 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 ‘(:``...``)
’
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 NULL_GLOB
.
Thus:
ls -ld -- *(-/)
lists all directories and symbolic links that point to directories, and
ls -ld -- *(-@)
lists all broken symbolic links, and
ls -ld -- *(%W)
ls -ld -- *(W,X)
lists all files in the current directory that are
print -rC1 /tmp/foo*(u0^@:t)
outputs the basename of all root-owned files beginning with the string
‘foo
’ in /tmp
, ignoring symlinks, and
ls -ld -- *.*~(lex|parse).[ch](^D^l1)
lists all files having a link count of one whose names contain a dot
(but not those starting with a dot, since GLOB_DOTS
is explicitly
switched off) except for lex.c
, lex.h
, parse.c
and parse.h
.
print -rC1 b*.pro(#q:s/pro/shmo/)(#q.:s/builtin/shmiltin/)
demonstrates how colon modifiers and other qualifiers may be chained
together. The ordinary qualifier ‘.
’ is applied first, then the colon
modifiers in order from left to right. So if EXTENDED_GLOB
is set and
the base pattern matches the regular file builtin.pro
, the shell will
print ‘shmiltin.shmo
’.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
15 Parameters
15.1 Description
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 ‘*
’, ‘@
’, ‘#
’, ‘?
’, ‘-
’, ‘$
’, or ‘!
’. A
parameter whose name begins with an alphanumeric or underscore is also
referred to as a variable.
The attributes of a parameter determine the type 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 scalar (a string, an integer, or a floating point number), an array (indexed numerically), or an associative array (an unordered set of name-value pairs, indexed by name, also referred to as a hash).
Named scalar parameters may have the exported, -x
, 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 environment variables. The shell also imports 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.
Parameters may also be special, 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.
To declare the type of a parameter, or to assign a string or numeric
value to a scalar parameter, use the typeset
builtin.
The value of a scalar parameter may also be assigned by writing:
name``=``value
In scalar assignment, value
is expanded as a single string, in which
the elements of arrays are joined together; filename expansion is not
performed unless the option GLOB_ASSIGN
is set.
When the integer attribute, -i
, or a floating point attribute, -E
or
-F
, is set for name
, the value
is subject to arithmetic
evaluation. Furthermore, by replacing ‘=
’ with ‘+=
’, a parameter can
be incremented or appended to. See Array Parameters
and Arithmetic
Evaluation for
additional forms of assignment.
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
GLOB_ASSIGN
assigning a pattern to a variable may change its type to
an array.
To reference the value of a parameter, write ‘$``name
’ or
‘${``name``}
’. See Parameter
Expansion for complete details.
That section also explains the effect of the difference between scalar
and array assignment on parameter expansion.
15.2 Array Parameters
To assign an array value, write one of:
set -A
name
value
...
name``=(``value
...)
name``=(``[``key``]=``value
...)
If no parameter name
exists, an ordinary array parameter is created.
If the parameter name
exists and is a scalar, it is replaced by a new
array.
In the third form, key
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 value
. 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: [
and ]=
must not
be quoted, and key
may not consist of the unquoted string ]=
, 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.
The syntaxes with and without the explicit key may be mixed. An implicit
key
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.
For example, assuming the option KSH_ARRAYS
is not set, the following:
array=(one [3]=three four)
causes the array variable array
to contain four elements one
, an
empty string, three
and four
, in that order.
In the forms where only value
is specified, full command line
expansion is performed.
In the [``key``]=``value
form, both key
and value
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 (e)
as described in Parameter
Expansion. Nested parentheses may
surround value
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:
name``=(``[a-z]’=’*)
To append to an array without changing the existing values, use one of the following:
name``+=(``value
...)
name``+=(``[``key``]=``value
...)
In the second form key
may specify an existing index as well as an
index off the end of the old array; any existing value is overwritten by
value
. Also, it is possible to use [``key``]+=``value
to append to
the existing value at that index.
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 value
s. Any consecutive sequence of such
characters has the same effect.
Ordinary array parameters may also be explicitly declared with:
typeset -a
name
Associative arrays must be declared before assignment, by using:
typeset -A
name
When name
refers to an associative array, the list in an assignment is
interpreted as alternating keys and values:
set -A
name
key
value
...
name``=(``key
value
...)
name``=(``[``key``]=``value
...)
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.
Every key
must have a value
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:
name``+=(``key
value
...)
name``+=(``[``key``]=``value
...)
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 [``key``]+=``value
to append to the existing
value at that key. Expansion is performed identically to the
corresponding forms for normal arrays, as described above.
To create an empty array (including associative arrays), use one of:
set -A
name
name``=()
15.2.1 Array Subscripts
Individual elements of an array may be selected using a subscript. A
subscript of the form ‘[``exp``]
’ selects the single element exp
,
where exp
is an arithmetic expression which will be subject to
arithmetic expansion as if it were surrounded by ‘$((
...))
’. The
elements are numbered beginning with 1, unless the KSH_ARRAYS
option
is set in which case they are numbered from zero.
Subscripts may be used inside braces used to delimit a parameter name,
thus ‘${foo[2]}
’ is equivalent to ‘$foo[2]
’. If the KSH_ARRAYS
option is set, the braced form is the only one that works, as bracketed
expressions otherwise are not treated as subscripts.
If the KSH_ARRAYS
option is not set, then by default accesses to an
array element with a subscript that evaluates to zero return an empty
string, while an attempt to write such an element is treated as an
error. For backward compatibility the KSH_ZERO_SUBSCRIPT
option can be
set to cause subscript values 0 and 1 to be equivalent; see the
description of the option in Description of
Options.
The same subscripting syntax is used for associative arrays, except that
no arithmetic expansion is applied to exp
. However, the parsing rules
for arithmetic expressions still apply, which affects the way that
certain special characters must be protected from interpretation. See
Subscript Parsing below for details.
A subscript of the form ‘[*]
’ or ‘[@]
’ evaluates to all elements of
an array; there is no difference between the two except when they appear
within double quotes. ‘"$foo[*]"
’ evaluates to ‘"$foo[1] $foo[2]
..."
’, whereas ‘"$foo[@]"
’ evaluates to ‘"$foo[1]" "$foo[2]"
...’. For associative arrays, ‘[*]
’ or ‘[@]
’ evaluate to all the
values, in no particular order. Note that this does not substitute the
keys; see the documentation for the ‘k
’ flag under Parameter
Expansion for complete details.
When an array parameter is referenced as ‘$``name
’ (with no subscript)
it evaluates to ‘$``name``[*]
’, unless the KSH_ARRAYS
option is set
in which case it evaluates to ‘${``name``[0]}
’ (for an associative
array, this means the value of the key ‘0
’, which may not exist even
if there are values for other keys).
A subscript of the form ‘[``exp1``,``exp2``]
’ selects all elements in
the range exp1
to exp2
, inclusive. (Associative arrays are
unordered, and so do not support ranges.) If one of the subscripts
evaluates to a negative number, say -``n
, then the n
th element from
the end of the array is used. Thus ‘$foo[-3]
’ is the third element
from the end of the array foo
, and ‘$foo[1,-1]
’ is the same as
‘$foo[*]
’.
Subscripting may also be performed on non-array values, in which case
the subscripts specify a substring to be extracted. For example, if
FOO
is set to ‘foobar
’, then ‘echo $FOO[2,5]
’ prints ‘ooba
’.
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,
string="abcdefghijklm"
print ${string[(r)d?,(r)h?]}
prints ‘defghi
’. 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).
Note that in substring operations the second subscript is handled
differently by the r
and R
subscript flags: the former takes the
shortest match as the length and the latter the longest match. Hence in
the former case a *
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.
15.2.2 Array Element Assignment
A subscript may be used on the left side of an assignment like so:
name``[``exp``]=``value
In this form of assignment the element or range specified by exp
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.)
This syntax also works as an argument to the typeset
command:
typeset
"``name``[``exp``]"=``value
The value
may not be a parenthesized list in this case; only
single-element assignments may be made with typeset
. Note that quotes
are necessary in this case to prevent the brackets from being
interpreted as filename generation operators. The noglob
precommand
modifier could be used instead.
To delete an element of an ordinary array, assign ‘()
’ to that
element. To delete an element of an associative array, use the unset
command:
unset
"``name``[``exp``]"
15.2.3 Subscript Flags
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
‘name``[(``flags``)``exp``]
’.
The flags s
, n
and b
take an argument; the delimiter is shown
below as ‘:
’, but any character, or the matching pairs ‘(
...)
’,
‘{
...}
’, ‘[
...]
’, or ‘<
...>
’, may be used, but note that
‘<
...>
’ 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.
The flags currently understood are:
-
w
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 thei
orI
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. -
s:``string``:
This gives thestring
that separates words (for use with thew
flag). The delimiter character:
is arbitrary; see above. -
p
Recognize the same escape sequences as theprint
builtin in the string argument of a subsequent ‘s
’ flag. -
f
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 ‘pws:\n:
’. -
r
Reverse subscripting: if this flag is given, theexp
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 ‘w
’ flag is given, respectively). The subscript used is the number of the matching element, so that pairs of subscripts such as ‘$foo[(r)??,3]
’ and ‘$foo[(r)??,(r)f*]
’ 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.If a search through an ordinary array failed, the search sets the subscript to one past the end of the array, and hence
${array[(r)``pattern``]}
will substitute the empty string. Thus the success of a search can be tested by using the(i)
flag, for example (assuming the optionKSH_ARRAYS
is not in effect):[[ ${array[(i)pattern]} -le ${#array} ]]
If
KSH_ARRAYS
is in effect, the-le
should be replaced by-lt
. -
R
Like ‘r
’, 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 optionsKSH_ARRAYS
orKSH_ZERO_SUBSCRIPT
is in effect.Note that in subscripts with both ‘
r
’ and ‘R
’ pattern characters are active even if they were substituted for a parameter (regardless of the setting ofGLOB_SUBST
which controls this feature in normal pattern matching). The flag ‘e
’ 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:key2='original key' print ${array[(Re)$key2]}
-
i
Like ‘r
’, 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 ‘r
’. 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 ‘r
’, or the empty string for an associative array. -
I
Like ‘i
’, 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. -
k
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 whereexp
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 ‘r
’. -
K
On an associative array this is like ‘k
’ but returns all values whereexp
is matched by the keys. On other types of parameters this has the same effect as ‘R
’. -
n:``expr``:
If combined with ‘r
’, ‘R
’, ‘i
’ or ‘I
’, makes them give then
th orn
th last match (ifexpr
evaluates ton
). This flag is ignored when the array is associative. The delimiter character:
is arbitrary; see above. -
b:``expr``:
If combined with ‘r
’, ‘R
’, ‘i
’ or ‘I
’, makes them begin at then
th orn
th last element, word, or character (ifexpr
evaluates ton
). This flag is ignored when the array is associative. The delimiter character:
is arbitrary; see above. -
e
This flag causes any pattern matching that would be performed on the subscript to use plain string matching instead. Hence ‘${array[(re)*]}
’ matches only the array element whose value is*
. Note that other forms of substitution such as parameter substitution are not inhibited.This flag can also be used to force
*
or@
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.
See Parameter Expansion Flags (Parameter Expansion) for additional ways to manipulate the results of array subscripting.
15.2.4 Subscript Parsing
This discussion applies mainly to associative array key strings and to
patterns used for reverse subscripting (the ‘r
’, ‘R
’, ‘i
’, etc.
flags), but it may also affect parameter substitutions that appear as
part of an arithmetic expression in an ordinary subscript.
To avoid subscript parsing limitations in assignments to associative array elements, use the append syntax:
aa+=('key with "*strange*" characters' 'value string')
The basic rule to remember when writing a subscript expression is that
all text between the opening ‘[
’ and the closing ‘]
’ is interpreted
as if it were in double quotes
(Quoting). 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.
The first difference is that brackets (‘[
’ and ‘]
’) must appear as
balanced pairs in a subscript expression unless they are preceded by a
backslash (‘\
’). Therefore, within a subscript expression (and unlike
true double-quoting) the sequence ‘\[
’ becomes ‘[
’, and similarly
‘\]
’ becomes ‘]
’. This applies even in cases where a backslash is
not normally required; for example, the pattern ‘[^[]
’ (to match any
character other than an open bracket) should be written ‘[^\[]
’ in a
reverse-subscript pattern. However, note that ‘\[^\[\]
’ and even
‘\[^[]
’ mean the same thing, because backslashes are always
stripped when they appear before brackets!
The same rule applies to parentheses (‘(
’ and ‘)
’) and braces (‘{
’
and ‘}
’): 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.
The second difference is that a double-quote (‘"
’) may appear as part
of a subscript expression without being preceded by a backslash, and
therefore that the two characters ‘\"
’ remain as two characters in the
subscript (in true double-quoting, ‘\"
’ becomes ‘"
’). 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 ‘\"
’ (rather than ‘\\\"
’) for
‘"
’.
To use an odd number of double quotes as a key in an assignment, use the
typeset
builtin and an enclosing pair of double quotes; to refer to
the value of that key, again use double quotes:
typeset -A aa
typeset "aa[one\"two\"three\"quotes]"=QQQ
print "$aa[one\"two\"three\"quotes]"
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.
A further complication arises from a way in which subscript parsing is
not different from double quote parsing. As in true double-quoting,
the sequences ‘\*
’, and ‘\@
’ remain as two characters when they
appear in a subscript expression. To use a literal ‘*
’ or ‘@
’ as an
associative array key, the ‘e
’ flag must be used:
typeset -A aa
aa[(e)*]=star
print $aa[(e)*]
A last detail must be considered when reverse subscripting is performed.
Parameters appearing in the subscript expression are first expanded and
then the complete expression is interpreted as a pattern. This has two
effects: first, parameters behave as if GLOB_SUBST
were on (and it
cannot be turned off); second, backslashes are interpreted twice, once
when parsing the array subscript and again when parsing the pattern. In
a reverse subscript, it’s necessary to use four backslashes to cause a
single backslash to match literally in the pattern. For complex
patterns, it is often easiest to assign the desired pattern to a
parameter and then refer to that parameter in the subscript, because
then the backslashes, brackets, parentheses, etc., are seen only when
the complete expression is converted to a pattern. To match the value of
a parameter literally in a reverse subscript, rather than as a pattern,
use ‘${(q``)``name``}
’ (Parameter
Expansion) to quote the expanded
value.
Note that the ‘k
’ and ‘K
’ flags are reverse subscripting for an
ordinary array, but are not 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.)
One final note, not directly related to subscripting: the numeric names
of positional parameters (Positional
Parameters) are parsed specially, so for
example ‘$2foo
’ is equivalent to ‘${2}foo
’. Therefore, to use
subscript syntax to extract a substring from a positional parameter, the
expansion must be surrounded by braces; for example, ‘${2[3,5]}
’
evaluates to the third through fifth characters of the second positional
parameter, but ‘$2[3,5]
’ is the entire second parameter concatenated
with the filename generation pattern ‘[3,5]
’.
15.3 Positional Parameters
The positional parameters provide access to the command-line arguments
of a shell function, shell script, or the shell itself; see
Invocation, and also
Functions. The parameter n
, where n
is a
number, is the n
th positional parameter. The parameter ‘$0
’ is a
special case, see Parameters Set By The
Shell.
The parameters *
, @
and argv
are arrays containing all the
positional parameters; thus ‘$argv[``n``]
’, etc., is equivalent to
simply ‘$``n
’. Note that the options KSH_ARRAYS
or
KSH_ZERO_SUBSCRIPT
apply to these arrays as well, so with either of
those options set, ‘${argv[0]}
’ is equivalent to ‘$1
’ and so on.
Positional parameters may be changed after the shell or function starts
by using the set
builtin, by assigning to the argv
array, or by
direct assignment of the form ‘n``=``value
’ where n
is the number of
the positional parameter to be changed. This also creates (with empty
values) any of the positions from 1 to n
that do not already have
values. Note that, because the positional parameters form an array, an
array assignment of the form ‘n``=(``value
...)
’ is allowed, and has
the effect of shifting all the values at positions greater than n
by
as many positions as necessary to accommodate the new values.
15.4 Local Parameters
Shell function executions delimit scopes for shell parameters.
(Parameters are dynamically scoped.) The typeset
builtin, and its
alternative forms declare
, integer
, local
and readonly
(but not
export
), can be used to declare a parameter as being local to the
innermost scope.
When a parameter is read or assigned to, the innermost existing
parameter of that name is used. (That is, the local parameter hides any
less-local parameter.) However, assigning to a non-existent parameter,
or declaring a new parameter with export
, causes it to be created in
the outermost scope.
Local parameters disappear when their scope ends. unset
can be used to
delete a parameter while it is still in scope; any outer parameter of
the same name remains hidden.
Special parameters may also be made local; they retain their special
attributes unless either the existing or the newly-created parameter has
the -h
(hide) attribute. This may have unexpected effects: there is no
default value, so if there is no assignment at the point the variable is
made local, it will be set to an empty value (or zero in the case of
integers). The following:
typeset PATH=/new/directory:$PATH
is valid for temporarily allowing the shell or programmes called from it
to find the programs in /new/directory
inside a function.
Note that the restriction in older versions of zsh that local parameters were never exported has been removed.
15.5 Parameters Set By The Shell
In the parameter lists that follow, the mark ‘<S>’ indicates that the
parameter is special. ‘<Z>’ indicates that the parameter does not
exist when the shell initializes in sh
or ksh
emulation mode.
The following parameters are automatically set by the shell:
!
<S>
The process ID of the last command started in the background with &
,
put into the background with the bg
builtin, or spawned with coproc
.
#
<S>
The number of positional parameters in decimal. Note that some confusion
may occur with the syntax $#``param
which substitutes the length of
param
. Use ${#}
to resolve ambiguities. In particular, the sequence
‘$#-``...
’ in an arithmetic expression is interpreted as the length
of the parameter -
, q.v.
ARGC
<S> <Z>
Same as #
.
$
<S>
The process ID of this shell. Note that this indicates the original
shell started by invoking zsh
; all processes forked from the shells
without executing a new program, such as subshells started by
(``...``)
, substitute the same value.
-
<S>
Flags supplied to the shell on invocation or by the set
or setopt
commands.
*
<S>
An array containing the positional parameters.
argv
<S> <Z>
Same as *
. Assigning to argv
changes the local positional
parameters, but argv
is not itself a local parameter. Deleting
argv
with unset
in any function deletes it everywhere, although only
the innermost positional parameter array is deleted (so *
and @
in
other scopes are not affected).
@
<S>
Same as argv[@]
, even when argv
is not set.
?
<S>
The exit status returned by the last command.
0
<S>
The name used to invoke the current shell, or as set by the -c
command
line option upon invocation. If the FUNCTION_ARGZERO
option is set,
$0
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.
status
<S> <Z>
Same as ?
.
pipestatus
<S> <Z>
An array containing the exit statuses returned by all commands in the last pipeline.
_
<S>
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.
CPUTYPE
The machine type (microprocessor class or machine model), as determined at run time.
EGID
<S>
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
‘(EGID=``gid``; command)
’
If this is made local, it is not implicitly set to 0, but may be explicitly set locally.
EUID
<S>
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
‘(EUID=``uid``; command)
’
If this is made local, it is not implicitly set to 0, but may be explicitly set locally.
ERRNO
<S>
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 zsh/system
module which
allows the number to be turned into a name or message.
FUNCNEST
<S>
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.
GID
<S>
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 ‘(GID=``gid``; command)
’
If this is made local, it is not implicitly set to 0, but may be explicitly set locally.
HISTCMD
The current history event number in an interactive shell, in other words
the event number for the command that caused $HISTCMD
to be read. If
the current history event modifies the history, HISTCMD
changes to the
new maximum history event number.
HOST
The current hostname.
LINENO
<S>
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 functions
builtin.
LOGNAME
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 typeset
builtin. The value is set to the string
returned by the man page getlogin(3) system call if that is available.
MACHTYPE
The machine type (microprocessor class or machine model), as determined at compile time.
OLDPWD
The previous working directory. This is set when the shell initializes and whenever the directory changes.
OPTARG
<S>
The value of the last option argument processed by the getopts
command.
OPTIND
<S>
The index of the last option argument processed by the getopts
command.
OSTYPE
The operating system, as determined at compile time.
PPID
<S>
The process ID of the parent of the shell. As for $$
, the value
indicates the parent of the original shell and does not change in
subshells.
PWD
The present working directory. This is set when the shell initializes and whenever the directory changes.
RANDOM
<S>
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 RANDOM
.
sequence; subshells that reference RANDOM
will result in identical
pseudo-random values unless the value of RANDOM
is referenced or
seeded in the parent shell in between subshell invocations.
SECONDS
<S>
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.
Unlike other special parameters, the type of the SECONDS
parameter can
be changed using the typeset
command. Only integer and one of the
floating point types are allowed. For example, ‘typeset -F SECONDS
’
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 typeset
. See the documentation
for the builtin typeset
in Shell Builtin
Commands for more
details.
SHLVL
<S>
Incremented by one each time a new shell is started.
signals
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 HUP
is
signal number 1, but is referred to as $signals[2]
. This is because of
EXIT
at position 1 in the array, which is used internally by zsh but
is not known to the operating system.
TRY_BLOCK_ERROR
<S>
In an always
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 Complex
Commands
TRY_BLOCK_INTERRUPT
<S>
This variable works in a similar way to TRY_BLOCK_ERROR
, but
represents the status of an interrupt from the signal SIGINT, which
typically comes from the keyboard when the user types ^C
. If set to 0,
any such interrupt will be reset; otherwise, the interrupt is propagated
after the always
block.
Note that it is possible that an interrupt arrives during the execution
of the always
block; this interrupt is also propagated.
TTY
The name of the tty associated with the shell, if any.
TTYIDLE
<S>
The idle time of the tty associated with the shell in seconds or -1 if there is no such tty.
UID
<S>
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 ‘(UID=``uid``; command)
’
If this is made local, it is not implicitly set to 0, but may be explicitly set locally.
USERNAME
<S>
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
‘(USERNAME=``username``; command)
’
VENDOR
The vendor, as determined at compile time.
zsh_eval_context
<S> <Z> (ZSH_EVAL_CONTEXT
<S>)
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.
Note that the variable does not give information on syntactic context
such as pipelines or subshells. Use $ZSH_SUBSHELL
to detect subshells.
The context is one of the following:
-
cmdarg
Code specified by the-c
option to the command line that invoked the shell. -
cmdsubst
Command substitution using the‘``...``‘
or$(``...``)
construct. -
equalsubst
File substitution using the=(``...``)
construct. -
eval
Code executed by theeval
builtin. -
evalautofunc
Code executed with theKSH_AUTOLOAD
mechanism in order to define an autoloaded function. -
fc
Code from the shell history executed by the-e
option to thefc
builtin. -
file
Lines of code being read directly from a file, for example by thesource
builtin. -
filecode
Lines of code being read from a.zwc
file instead of directly from the source file. -
globqual
Code executed by thee
or+
glob qualifier. -
globsort
Code executed to order files by theo
glob qualifier. -
insubst
File substitution using the<(``...``)
construct. -
loadautofunc
Code read directly from a file to define an autoloaded function. -
outsubst
File substitution using the>(``...``)
construct. -
sched
Code executed by thesched
builtin. -
shfunc
A shell function. -
stty
Code passed tostty
by theSTTY
environment variable. Normally this is passed directly to the system’sstty
command, so this value is unlikely to be seen in practice. -
style
Code executed as part of a style retrieved by thezstyle
builtin from thezsh/zutil
module. -
toplevel
The highest execution level of a script or interactive shell. -
trap
Code executed as a trap defined by thetrap
builtin. Traps defined as functions have the contextshfunc
. As traps are asynchronous they may have a different hierarchy from other code. -
zpty
Code executed by thezpty
builtin from thezsh/zpty
module. -
zregexparse-guard
Code executed as a guard by thezregexparse
command from thezsh/zutil
module. -
zregexparse-action
Code executed as an action by thezregexparse
command from thezsh/zutil
module.
ZSH_ARGZERO
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 $0
when the POSIX_ARGZERO
option is set, but is
always available.
ZSH_EXECUTION_STRING
If the shell was started with the option -c
, this contains the
argument passed to the option. Otherwise it is not set.
ZSH_NAME
Expands to the basename of the command used to invoke this instance of zsh.
ZSH_PATCHLEVEL
The output of ‘git describe –tags –long
’ 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 $ZSH_VERSION
.
zsh_scheduled_events
See The zsh/sched Module.
ZSH_SCRIPT
If zsh was invoked to run a script, this is the name of the script, otherwise it is unset.
ZSH_SUBSHELL
Readonly integer. Initially zero, incremented each time the shell forks
to create a subshell for executing code. Hence ‘(print $ZSH_SUBSHELL)
’
and ‘print $(print $ZSH_SUBSHELL)
’ output 1, while ‘( (print $ZSH_SUBSHELL) )
’ outputs 2.
ZSH_VERSION
The version number of the release of zsh.
15.6 Parameters Used By The Shell
The following parameters are used by the shell. Again, ‘<S>’ indicates
that the parameter is special and ‘<Z>’ indicates that the parameter
does not exist when the shell initializes in sh
or ksh
emulation
mode.
In cases where there are two parameters with an upper- and lowercase
form of the same name, such as path
and PATH
, 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 ‘typeset -T
’. 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.
ARGV0
If exported, its value is used as the argv[0]
of external commands.
Usually used in constructs like ‘ARGV0=emacs nethack
’.
BAUD
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.
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.
cdpath
<S> <Z> (CDPATH
<S>)
An array (colon-separated list) of directories specifying the search
path for the cd
command.
COLUMNS
<S>
The number of columns for this terminal session. Used for printing select lists and for the line editor.
CORRECT_IGNORE
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 ‘_*
’ then completion functions (which, by convention,
have names beginning with ‘_
’) will never be offered as spelling
corrections. The pattern does not apply to the correction of file names,
as applied by the CORRECT_ALL
option (so with the example just given
files beginning with ‘_
’ in the current directory would still be
completed).
CORRECT_IGNORE_FILE
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 ‘.*
’ then dot file names will
never be offered as spelling corrections. This is useful with the
CORRECT_ALL
option.
DIRSTACKSIZE
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 AUTO_PUSHD
option.
ENV
If the ENV
environment variable is set when zsh is invoked as sh
or
ksh
, $ENV
is sourced after the profile scripts. The value of ENV
is subjected to parameter expansion, command substitution, and
arithmetic expansion before being interpreted as a pathname. Note that
ENV
is not used unless the shell is interactive and zsh is emulating
sh or ksh.
FCEDIT
The default editor for the fc
builtin. If FCEDIT
is not set, the
parameter EDITOR
is used; if that is not set either, a builtin
default, usually vi
, is used.
fignore
<S> <Z> (FIGNORE
<S>)
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.
fpath
<S> <Z> (FPATH
<S>)
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.
histchars
<S>
Three characters used by the shell’s history and lexical analysis
mechanism. The first character signals the start of a history expansion
(default ‘!
’). The second character signals the start of a quick
history substitution (default ‘^
’). The third character is the comment
character (default ‘#
’).
The characters must be in the ASCII character set; any attempt to set
histchars
to characters with a locale-dependent meaning will be
rejected with an error message.
HISTCHARS
<S> <Z>
Same as histchars
. (Deprecated.)
HISTFILE
The file to save the history in when an interactive shell exits. If unset, the history is not saved.
HISTORY_IGNORE
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 ‘fc *
’ then commands that invoke the
interactive history editor are never written to the history file.
Note that HISTORY_IGNORE
defines a single pattern: to specify
alternatives use the ‘(``first``|``second``|``...``)
’ syntax.
Compare the HIST_NO_STORE
option or the zshaddhistory
hook, either
of which would prevent such commands from being added to the interactive
history at all. If you wish to use HISTORY_IGNORE
to stop history
being added in the first place, you can define the following hook:
zshaddhistory() {
emulate -L zsh
## uncomment if HISTORY_IGNORE
## should use EXTENDED_GLOB syntax
# setopt extendedglob
[[ $1 != ${~HISTORY_IGNORE} ]]
}
HISTSIZE
<S>
The maximum number of events stored in the internal history list. If you
use the HIST_EXPIRE_DUPS_FIRST
option, setting this value larger than
the SAVEHIST
size will give you the difference as a cushion for saving
duplicated history events.
If this is made local, it is not implicitly set to 0, but may be explicitly set locally.
HOME
<S>
The default argument for the cd
command. This is not set automatically
by the shell in sh
, ksh
or csh
emulation, but it is typically
present in the environment anyway, and if it becomes set it has its
usual special behaviour.
IFS
<S>
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 read
builtin. Any characters from the
set space, tab and newline that appear in the IFS are called IFS white
space. 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.
If the parameter is unset, the default is used. Note this has a different effect from setting the parameter to an empty string.
KEYBOARD_HACK
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 SUNKEYBOARDHACK
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.
For backward compatibility, if the SUNKEYBOARDHACK
option is
explicitly set, the value of KEYBOARD_HACK
reverts to backquote. If
the option is explicitly unset, this variable is set to empty.
KEYTIMEOUT
The time the shell waits, in hundredths of seconds, for another key to be pressed when reading bound multi-character sequences.
LANG
<S>
This variable determines the locale category for any category not
specifically selected via a variable starting with ‘LC_
’.
LC_ALL
<S>
This variable overrides the value of the ‘LANG
’ variable and the value
of any of the other variables starting with ‘LC_
’.
LC_COLLATE
<S>
This variable determines the locale category for character collation information within ranges in glob brackets and for sorting.
LC_CTYPE
<S>
This variable determines the locale category for character handling
functions. If the MULTIBYTE
option is in effect this variable or
LANG
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 en_US.ISO8859-1
(MacOS).
LC_MESSAGES
<S>
This variable determines the language in which messages should be written. Note that zsh does not use message catalogs.
LC_NUMERIC
<S>
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.
LC_TIME
<S>
This variable determines the locale category for date and time formatting in prompt escape sequences.
LINES
<S>
The number of lines for this terminal session. Used for printing select lists and for the line editor.
LISTMAX
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.
LOGCHECK
The interval in seconds between checks for login/logout activity using
the watch
parameter.
MAIL
If this parameter is set and mailpath
is not set, the shell looks for
mail in the specified file.
MAILCHECK
The interval in seconds between checks for new mail.
mailpath
<S> <Z> (MAILPATH
<S>)
An array (colon-separated list) of filenames to check for new mail. Each
filename can be followed by a ‘?
’ and a message that will be printed.
The message will undergo parameter expansion, command substitution and
arithmetic expansion with the variable $_
defined as the name of the
file that has changed. The default message is ‘You have new mail
’. If
an element is a directory instead of a file the shell will recursively
check every file in every subdirectory of the element.
manpath
<S> <Z> (MANPATH
<S> <Z>)
An array (colon-separated list) whose value is not used by the shell.
The manpath
array can be useful, however, since setting it also sets
MANPATH
, and vice versa.
match
mbegin
mend
Arrays set by the shell when the b
globbing flag is used in pattern
matches. See the subsection Globbing flags in Filename
Generation.
MATCH
MBEGIN
MEND
Set by the shell when the m
globbing flag is used in pattern matches.
See the subsection Globbing flags in Filename
Generation.
module_path
<S> <Z> (MODULE_PATH
<S>)
An array (colon-separated list) of directories that zmodload
searches
for dynamically loadable modules. This is initialized to a standard
pathname, usually ‘/usr/local/lib/zsh/$ZSH_VERSION
’. (The
‘/usr/local/lib
’ part varies from installation to installation.) For
security reasons, any value set in the environment when the shell is
started will be ignored.
These parameters only exist if the installation supports dynamic module loading.
NULLCMD
<S>
The command name to assume if a redirection is specified with no
command. Defaults to cat
. For sh/ksh behavior, change this to :
. For
csh-like behavior, unset this parameter; the shell will print an error
message if null commands are entered.
path
<S> <Z> (PATH
<S>)
An array (colon-separated list) of directories to search for commands. When this parameter is set, each directory is scanned
POSTEDIT
<S>
This string is output whenever the line editor exits. It usually contains termcap strings to reset the terminal.
PROMPT
<S> <Z>
PROMPT2
<S> <Z>
PROMPT3
<S> <Z>
PROMPT4
<S> <Z>
Same as PS1
, PS2
, PS3
and PS4
, respectively.
prompt
<S> <Z>
Same as PS1
.
PROMPT_EOL_MARK
When the PROMPT_CR
and PROMPT_SP
options are set, the
PROMPT_EOL_MARK
parameter can be used to customize how the end of
partial lines are shown. This parameter undergoes prompt expansion, with
the PROMPT_PERCENT
option set. If not set, the default behavior is
equivalent to the value ‘%B%S%#%s%b
’.
PS1
<S>
The primary prompt string, printed before a command is read. It
undergoes a special form of expansion before being displayed; see
Prompt Expansion. The default
is ‘%m%#
’.
PS2
<S>
The secondary prompt, printed when the shell needs more information to
complete a command. It is expanded in the same way as PS1
. The default
is ‘%_>
’, which displays any shell constructs or quotation marks
which are currently being processed.
PS3
<S>
Selection prompt used within a select
loop. It is expanded in the same
way as PS1
. The default is ‘?#
’.
PS4
<S>
The execution trace prompt. Default is ‘+%N:%i>
’, which displays
the name of the current shell structure and the line number within it.
In sh or ksh emulation, the default is ‘+
’.
psvar
<S> <Z> (PSVAR
<S>)
An array (colon-separated list) whose elements can be used in PROMPT
strings. Setting psvar
also sets PSVAR
, and vice versa.
READNULLCMD
<S>
The command name to assume if a single input redirection is specified
with no command. Defaults to more
.
REPORTMEMORY
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 TIMEFMT
parameter, which is the same as for the
REPORTTIME
variable and the time
builtin; note that by default this
does not output memory usage. Appending " max RSS %M"
to the value of
TIMEFMT
causes it to output the value that triggered the report. If
REPORTTIME
is also in use, at most a single report is printed for both
triggers. This feature requires the getrusage()
system call, commonly
supported by modern Unix-like systems.
REPORTTIME
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
time
keyword still cause the summary to be printed in this case.
REPLY
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 read
builtin and the
select
complex command may set REPLY
, and filename generation both
sets and examines its value when evaluating certain expressions. Some
modules also employ REPLY
for similar purposes.
reply
As REPLY
, but for array values rather than strings.
RPROMPT
<S>
RPS1
<S>
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
SINGLE_LINE_ZLE
option is set. It is expanded in the same way as
PS1
.
RPROMPT2
<S>
RPS2
<S>
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 SINGLE_LINE_ZLE
option is set. It is expanded in the same way as
PS2
.
SAVEHIST
The maximum number of history events to save in the history file.
If this is made local, it is not implicitly set to 0, but may be explicitly set locally.
SPROMPT
<S>
The prompt used for spelling correction. The sequence ‘%R
’ expands to
the string which presumably needs spelling correction, and ‘%r
’
expands to the proposed correction. All other prompt escapes are also
allowed.
The actions available at the prompt are [nyae]
:
-
n
(‘no’) (default)
Discard the correction and run the command. -
y
(‘yes’)
Make the correction and run the command. -
a
(‘abort’)
Discard the entire command line without running it. -
e
(‘edit’)
Resume editing the command line.
STTY
If this parameter is set in a command’s environment, the shell runs the
stty
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 fg
or wait
builtins it will see the modes specified by STTY
, as if it were not
suspended. This (intentionally) does not apply if the command is
continued via ‘kill -CONT
’. STTY
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
STTY
should not be used for window size specifications; these will not
be local to the command.
TERM
<S>
The type of terminal in use. This is used when looking up termcap
sequences. An assignment to TERM
causes zsh to re-initialize the
terminal, even if the value does not change (e.g., ‘TERM=$TERM
’). It
is necessary to make such an assignment upon any change to the terminal
definition database or terminal type in order for the new settings to
take effect.
TERMINFO
<S>
A reference to your terminfo database, used by the ‘terminfo’ library
when the system has it; see man page terminfo(5). If set, this causes
the shell to reinitialise the terminal, making the workaround
‘TERM=$TERM
’ unnecessary.
TERMINFO_DIRS
<S>
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
‘TERM=$TERM
’ unnecessary. Note that unlike other colon-separated
arrays this is not tied to a zsh array.
TIMEFMT
The format of process time reports with the time
keyword. The default
is ‘%J %U user %S system %P cpu %*E total
’. Recognizes the following
escape sequences, although not all may be available on all systems, and
some that are available may not be useful:
-
%%
A ‘%
’. -
%U
CPU seconds spent in user mode. -
%S
CPU seconds spent in kernel mode. -
%E
Elapsed time in seconds. -
%P
The CPU percentage, computed as 100*(%U
+%S
)/%E
. -
%W
Number of times the process was swapped. -
%X
The average amount in (shared) text space used in kilobytes. -
%D
The average amount in (unshared) data/stack space used in kilobytes. -
%K
The total space used (%X
+%D
) in kilobytes. -
%M
The maximum memory the process had in use at any time in kilobytes. -
%F
The number of major page faults (page needed to be brought from disk). -
%R
The number of minor page faults. -
%I
The number of input operations. -
%O
The number of output operations. -
%r
The number of socket messages received. -
%s
The number of socket messages sent. -
%k
The number of signals received. -
%w
Number of voluntary context switches (waits). -
%c
Number of involuntary context switches. -
%J
The name of this job.
A star may be inserted between the percent sign and flags printing time
(e.g., ‘%*E
’); this causes the time to be printed in
‘hh``:``mm``:``ss``.``ttt
’ format (hours and minutes are only
printed if they are not zero). Alternatively, ‘m
’ or ‘u
’ may be used
(e.g., ‘%mE
’) to produce time output in milliseconds or microseconds,
respectively.
TMOUT
If this parameter is nonzero, the shell will receive an ALRM
signal if
a command is not entered within the specified number of seconds after
issuing a prompt. If there is a trap on SIGALRM
, it will be executed
and a new alarm is scheduled using the value of the TMOUT
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 TMOUT
parameter, zsh
terminates. Otherwise a new alarm is scheduled to TMOUT
seconds after
the last keypress.
TMPPREFIX
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 ‘/tmp/zsh
’.
TMPSUFFIX
A filename suffix which the shell will use for temporary files created
by process substitutions (e.g., ‘=(list)
’). Note that the value should
include a leading dot ‘.
’ 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.
watch
<S> <Z> (WATCH
<S>)
An array (colon-separated list) of login/logout events to report.
If it contains the single word ‘all
’, then all login/logout events are
reported. If it contains the single word ‘notme
’, then all events are
reported as with ‘all
’ except $USERNAME
.
An entry in this list may consist of a username, an ‘@
’ followed by a
remote hostname, and a ‘%
’ followed by a line (tty). Any of these may
be a pattern (be sure to quote this during the assignment to watch
so
that it does not immediately perform file generation); the setting of
the EXTENDED_GLOB
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.
For example, with the EXTENDED_GLOB
option set, the following:
watch=('^(pws|barts)')
causes reports for activity associated with any user other than pws
or
barts
.
WATCHFMT
The format of login/logout reports if the watch
parameter is set.
Default is ‘%n has %a %l from %m
’. Recognizes the following escape
sequences:
-
%n
The name of the user that logged in/out. -
%a
The observed action, i.e. "logged on" or "logged off". -
%l
The line (tty) the user is logged in on. -
%M
The full hostname of the remote host. -
%m
The hostname up to the first ‘.
’. If only the IP address is available or the utmp field contains the name of an X-windows display, the whole name is printed.NOTE: The ‘
%m
’ and ‘%M
’ escapes will work only if there is a host name field in the utmp on your machine. Otherwise they are treated as ordinary strings. -
%S
(%s
)
Start (stop) standout mode. -
%U
(%u
)
Start (stop) underline mode. -
%B
(%b
)
Start (stop) boldface mode. -
%t
%@
The time, in 12-hour, am/pm format. -
%T
The time, in 24-hour format. -
%w
The date in ‘day``-``dd
’ format. -
%W
The date in ‘mm``/``dd``/``yy
’ format. -
%D
The date in ‘yy``-``mm``-``dd
’ format. -
%D{``string``}
The date formatted asstring
using thestrftime
function, with zsh extensions as described by Prompt Expansion. -
%(``x``:``true-text``:``false-text``)
Specifies a ternary expression. The character following thex
is arbitrary; the same character is used to separate the text for the "true" result from that for the "false" result. Both the separator and the right parenthesis may be escaped with a backslash. Ternary expressions may be nested.The test character
x
may be any one of ‘l
’, ‘n
’, ‘m
’ or ‘M
’, which indicate a ‘true’ result if the corresponding escape sequence would return a non-empty value; or it may be ‘a
’, 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.If the result is ‘true’, then the
true-text
is formatted according to the rules above and printed, and thefalse-text
is skipped. If ‘false’, thetrue-text
is skipped and thefalse-text
is formatted and printed. Either or both of the branches may be empty, but both separators must be present in any case.
WORDCHARS
<S>
A list of non-alphanumeric characters considered part of a word by the line editor.
ZBEEP
If set, this gives a string of characters, which can use all the same
codes as the bindkey
command as described in The zsh/zle
Module, that will be output to
the terminal instead of beeping. This may have a visible instead of an
audible effect; for example, the string ‘\e[?5h\e[?5l
’ 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 ‘\e[?5l\e[?5h
’
instead). This takes precedence over the NOBEEP
option.
ZDOTDIR
The directory to search for shell startup files (.zshrc, etc), if not
$HOME
.
zle_bracketed_paste
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.
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.
zle_highlight
An array describing contexts in which ZLE should highlight the input text. See Character Highlighting.
ZLE_LINE_ABORTED
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.
‘print -zr – $ZLE_LINE_ABORTED
’ can be used to recover the line.
Only the most recent line of this kind is remembered.
ZLE_REMOVE_SUFFIX_CHARS
ZLE_SPACE_SUFFIX_CHARS
These parameters are used by the line editor. In certain circumstances suffixes (typically space or slash) added by the completion system will be removed automatically, either because the next editing command as requiring the suffix to be removed.
These variables can contain the sets of characters that will cause the
suffix to be removed. If ZLE_REMOVE_SUFFIX_CHARS
is set, those
characters will cause the suffix to be removed; if
ZLE_SPACE_SUFFIX_CHARS
is set, those characters will cause the suffix
to be removed and replaced by a space.
If ZLE_REMOVE_SUFFIX_CHARS
is not set, the default behaviour is
equivalent to:
ZLE_REMOVE_SUFFIX_CHARS=$' \t\n;&|'
If ZLE_REMOVE_SUFFIX_CHARS
is set but is empty, no characters have
this behaviour. ZLE_SPACE_SUFFIX_CHARS
takes precedence, so that the
following:
ZLE_SPACE_SUFFIX_CHARS=$'&|'
causes the characters ‘&
’ and ‘|
’ to remove the suffix but to
replace it with a space.
To illustrate the difference, suppose that the option
AUTO_REMOVE_SLASH
is in effect and the directory DIR
has just been
completed, with an appended /
, following which the user types ‘&
’.
The default result is ‘DIR&
’. With ZLE_REMOVE_SUFFIX_CHARS
set but
without including ‘&
’ the result is ‘DIR/&
’. With
ZLE_SPACE_SUFFIX_CHARS
set to include ‘&
’ the result is ‘DIR &
’.
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 Completion System.
ZLE_RPROMPT_INDENT
<S>
If set, used to give the indentation between the right hand side of the
right prompt in the line editor as given by RPS1
or RPROMPT
and the
right hand side of the screen. If not set, the value 1 is used.
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.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 16 Options
16 Options
16.1 Specifying Options
Options are primarily referred to by name. These names are case
insensitive and underscores are ignored. For example, ‘allexport
’ is
equivalent to ‘A__lleXP_ort
’.
The sense of an option name may be inverted by preceding it with ‘no
’,
so ‘setopt No_Beep
’ is equivalent to ‘unsetopt beep
’. This inversion
can only be done once, so ‘nonobeep
’ is not a synonym for ‘beep
’.
Similarly, ‘tify
’ is not a synonym for ‘nonotify
’ (the inversion of
‘notify
’).
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 SH_OPTION_LETTERS
option is set). The
single letter options can be used on the shell command line, or with the
set
, setopt
and unsetopt
builtins, as normal Unix options preceded
by ‘-
’.
The sense of the single letter options may be inverted by using ‘+
’
instead of ‘-
’. 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, ‘+n
’ is the short name of ‘exec
’, and
‘-n
’ is the short name of its inversion, ‘noexec
’.
In strings of single letter options supplied to the shell at startup,
trailing whitespace will be ignored; for example the string ‘-f
’
will be treated just as ‘-f
’, but the string ‘-f i
’ is an error.
This is because many systems which implement the ‘#!
’ mechanism for
calling scripts do not strip trailing whitespace.
16.2 Description of Options
In the following list, options set by default in all emulations are
marked <D>; those set by default only in csh, ksh, sh, or zsh
emulations are marked <C>, <K>, <S>, <Z> as appropriate. When
listing options (by ‘setopt
’, ‘unsetopt
’, ‘set -o
’ or ‘set +o
’),
those turned on by default appear in the list prefixed with ‘no
’.
Hence (unless KSH_OPTION_PRINT
is set), ‘setopt
’ shows all options
whose settings are changed from the default.
16.2.1 Changing Directories
AUTO_CD
(-J
)
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 cd
command to that
directory. This option is only applicable if the option SHIN_STDIN
is
set, i.e. if commands are being read from standard input. The option is
designed for interactive use; it is recommended that cd
be used
explicitly in scripts to avoid ambiguity.
AUTO_PUSHD
(-N
)
Make cd
push the old directory onto the directory stack.
CDABLE_VARS
(-T
)
If the argument to a cd
command (or an implied cd
with the AUTO_CD
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 ‘~
’ (see Filename
Expansion).
CD_SILENT
Never print the working directory after a cd
(whether explicit or
implied with the AUTO_CD
option set). cd
normally prints the working
directory when the argument given to it was -
, a stack entry, or the
name of a directory found under CDPATH
. Note that this is distinct
from pushd
’s stack-printing behaviour, which is controlled by
PUSHD_SILENT
. This option overrides the printing-related effects of
POSIX_CD
.
CHASE_DOTS
When changing to a directory containing a path segment ‘..
’ which
would otherwise be treated as canceling the previous segment in the path
(in other words, ‘foo/..
’ would be removed from the path, or if ‘..
’
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 CHASE_LINKS
.
For example, suppose /foo/bar
is a link to the directory /alt/rod
.
Without this option set, ‘cd /foo/bar/..
’ changes to /foo
; with it
set, it changes to /alt
. The same applies if the current directory is
/foo/bar
and ‘cd ..
’ is used. Note that all other symbolic links in
the path will also be resolved.
CHASE_LINKS
(-w
)
Resolve symbolic links to their true values when changing directory.
This also has the effect of CHASE_DOTS
, i.e. a ‘..
’ path segment
will be treated as referring to the physical parent, even if the
preceding path segment is a symbolic link.
POSIX_CD
<K> <S>
Modifies the behaviour of cd
, chdir
and pushd
commands to make
them more compatible with the POSIX standard. The behaviour with the
option unset is described in the documentation for the cd
builtin in
Shell Builtin
Commands. If the
option is set, the shell does not test for directories beneath the local
directory (‘.
’) until after all directories in cdpath
have been
tested, and the cd
and chdir
commands do not recognise arguments of
the form ‘{+
|-
}n
’ as directory stack entries.
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 pushd
is still limited to interactive shells); and any use
of a component of CDPATH
, including a ‘.
’ but excluding an empty
component that is otherwise treated as ‘.
’, causes the directory to be
printed.
PUSHD_IGNORE_DUPS
Don’t push multiple copies of the same directory onto the directory stack.
PUSHD_MINUS
Exchanges the meanings of ‘+
’ and ‘-
’ when used with a number to
specify a directory in the stack.
PUSHD_SILENT
(-E
)
Do not print the directory stack after pushd
or popd
.
PUSHD_TO_HOME
(-D
)
Have pushd
with no arguments act like ‘pushd $HOME
’.
16.2.2 Completion
ALWAYS_LAST_PROMPT
<D>
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 no numeric argument.
ALWAYS_TO_END
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.
AUTO_LIST
(-9
) <D>
Automatically list choices on an ambiguous completion.
AUTO_MENU
<D>
Automatically use menu completion after the second consecutive request
for completion, for example by pressing the tab key repeatedly. This
option is overridden by MENU_COMPLETE
.
AUTO_NAME_DIRS
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
‘%~
’ and related prompt sequences, and will be available when
completion is performed on a word starting with ‘~
’. (Otherwise, the
parameter must be used in the form ‘~``param
’ first.)
AUTO_PARAM_KEYS
<D>
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 ‘}
’, ‘:
’,
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
‘,
’, which will be removed if ‘}
’ is typed next.
AUTO_PARAM_SLASH
<D>
If a parameter is completed whose content is the name of a directory, then add a trailing slash instead of a space.
AUTO_REMOVE_SLASH
<D>
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.
BASH_AUTO_LIST
On an ambiguous completion, automatically list choices when the
completion function is called twice in succession. This takes precedence
over AUTO_LIST
. The setting of LIST_AMBIGUOUS
is respected. If
AUTO_MENU
is set, the menu behaviour will then start with the third
press. Note that this will not work with MENU_COMPLETE
, since repeated
completion calls immediately cycle through the list in that case.
COMPLETE_ALIASES
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.
COMPLETE_IN_WORD
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.
GLOB_COMPLETE
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 MENU_COMPLETE
. The matches are generated as if
a ‘*
’ was added to the end of the word, or inserted at the cursor when
COMPLETE_IN_WORD
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.
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 GLOB_COMPLETE
option does not have this effect.
HASH_LIST_ALL
<D>
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.
LIST_AMBIGUOUS
<D>
This option works when AUTO_LIST
or BASH_AUTO_LIST
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 BASH_AUTO_LIST
, this means that the list will be
delayed to the third call of the function.
LIST_BEEP
<D>
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 BEEP
is also set; this may be
modified if completion is called from a user-defined widget.
LIST_PACKED
Try to make the completion list smaller (occupying less lines) by printing the matches in columns with different widths.
LIST_ROWS_FIRST
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.
LIST_TYPES
(-X
) <D>
When listing files that are possible completions, show the type of each file with a trailing identifying mark.
MENU_COMPLETE
(-Y
)
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.
reverse-menu-complete
may be used to loop through the list in the
other direction. This option overrides AUTO_MENU
.
REC_EXACT
(-S
)
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.
16.2.3 Expansion and Globbing
BAD_PATTERN
(+2
) <C> <Z>
If a pattern for filename generation is badly formed, print an error message. (If this option is unset, the pattern will be left unchanged.)
BARE_GLOB_QUAL
<Z>
In a glob pattern, treat a trailing set of parentheses as a qualifier
list, if it contains no ‘|
’, ‘(
’ or (if special) ‘~
’ characters.
See Filename Generation.
BRACE_CCL
Expand expressions in braces which would not otherwise undergo brace expansion to a lexically ordered list of all the characters. See Brace Expansion.
CASE_GLOB
<D>
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, cvs(/)
can match
the directory CVS
owing to the presence of the globbing flag (unless
the option BARE_GLOB_QUAL
is unset).
CASE_MATCH
<D>
Make regular expressions using the zsh/regex
module (including matches
with =~
) sensitive to case.
CSH_NULL_GLOB
<C>
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 NOMATCH
.
EQUALS
<Z>
Perform =
filename expansion. (See Filename
Expansion.)
EXTENDED_GLOB
Treat the ‘#
’, ‘~
’ and ‘^
’ characters as part of patterns for
filename generation, etc. (An initial unquoted ‘~
’ always produces
named directory expansion.)
FORCE_FLOAT
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.
GLOB
(+F
, ksh: +f
) <D>
Perform filename generation (globbing). (See Filename Generation.)
GLOB_ASSIGN
<C>
If this option is set, filename generation (globbing) is performed on
the right hand side of scalar parameter assignments of the form
‘name``=``pattern
(e.g. ‘foo=*
’). 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
‘name``=(``value``)
’ (e.g. ‘foo=(*)
’) 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.
GLOB_DOTS
(-4
)
Do not require a leading ‘.
’ in a filename to be matched explicitly.
GLOB_STAR_SHORT
When this option is set and the default zsh-style globbing is in effect,
the pattern ‘**/*
’ can be abbreviated to ‘**
’ and the pattern
‘***/*
’ can be abbreviated to ***
. Hence ‘**.c
’ finds a file
ending in .c
in any subdirectory, and ‘***.c
’ does the same while
also following symbolic links. A /
immediately after the ‘**
’ or
‘***
’ forces the pattern to be treated as the unabbreviated form.
GLOB_SUBST
<C> <K> <S>
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.
HIST_SUBST_PATTERN
Substitutions using the :s
and :&
history modifiers are performed
with pattern matching instead of string matching. This occurs wherever
history modifiers are valid, including glob qualifiers and parameters.
See Modifiers.
IGNORE_BRACES
(-I
) <S>
Do not perform brace expansion. For historical reasons this also
includes the effect of the IGNORE_CLOSE_BRACES
option.
IGNORE_CLOSE_BRACES
When neither this option nor IGNORE_BRACES
is set, a sole close brace
character ‘}
’ 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 IGNORE_BRACES
, this option does not
disable brace expansion.
For example, with both options unset a function may be defined in the following fashion:
args() { echo $# }
while if either option is set, this does not work and something equivalent to the following is required:
args() { echo $#; }
KSH_GLOB
<K>
In pattern matching, the interpretation of parentheses is affected by a
preceding ‘@
’, ‘*
’, ‘+
’, ‘?
’ or ‘!
’. See Filename
Generation.
MAGIC_EQUAL_SUBST
All unquoted arguments of the form ‘anything``=``expression
’ appearing
after the command name have filename expansion (that is, where
expression
has a leading ‘~
’ or ‘=
’) performed on expression
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 echo foo=~/bar:~/rod
, both occurrences of ~
would be replaced. Note that
this happens anyway with typeset
and similar statements.
This option respects the setting of the KSH_TYPESET
option. In other
words, if both options are in effect, arguments looking like assignments
will not undergo word splitting.
MARK_DIRS
(-8
, ksh: -X
)
Append a trailing ‘/
’ to all directory names resulting from filename
generation (globbing).
MULTIBYTE
<D>
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.
The option is on by default if the shell was compiled with
MULTIBYTE_SUPPORT
; otherwise it is off by default and has no effect if
turned on.
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.
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.
NOMATCH
(+3
) <C> <Z>
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 ‘~
’ or ‘=
’.
NULL_GLOB
(-G
)
If a pattern for filename generation has no matches, delete the pattern
from the argument list instead of reporting an error. Overrides
NOMATCH
.
NUMERIC_GLOB_SORT
If numeric filenames are matched by a filename generation pattern, sort the filenames numerically rather than lexicographically.
RC_EXPAND_PARAM
(-P
)
Array expansions of the form ‘foo``${``xx``}``bar
’, where the
parameter xx
is set to (``a b c``)
, are substituted with ‘fooabar foobbar foocbar
’ instead of the default ‘fooa b cbar
’. Note that an
empty array will therefore cause all arguments to be removed.
REMATCH_PCRE
If set, regular expression matching with the =~
operator will use
Perl-Compatible Regular Expressions from the PCRE library. (The
zsh/pcre
module must be available.) If not set, regular expressions
will use the extended regexp syntax provided by the system libraries.
SH_GLOB
<K> <S>
Disables the special meaning of ‘(
’, ‘|
’, ‘)
’ and ’<
’ for
globbing the result of parameter and command substitutions, and in some
other places where the shell accepts patterns. If SH_GLOB
is set but
KSH_GLOB
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. !(true)
is interpreted as
if there were a space after the !
. This option is set by default if
zsh is invoked as sh
or ksh
.
UNSET
(+u
, ksh: +u
) <K> <S> <Z>
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.
WARN_CREATE_GLOBAL
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
typeset -g
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.
WARN_NESTED_VAR
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 WARN_CREATE_GLOBAL
as in this case
the warning is only printed when a parameter is not created. Where
possible, use of typeset -g
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
‘functions -W
’.
For example, the following code produces a warning for the assignment
inside the function nested
as that overrides the value within
toplevel
toplevel() {
local foo="in fn"
nested
}
nested() {
foo="in nested"
}
setopt warn_nested_var
toplevel
16.2.4 History
APPEND_HISTORY
<D>
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 $SAVEHIST
(see also the
HIST_SAVE_BY_COPY
option).
BANG_HIST
(+K
) <C> <Z>
Perform textual history expansion, csh-style, treating the character
‘!
’ specially.
EXTENDED_HISTORY
<C>
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:
‘ : ``<beginning time>``:``<elapsed seconds>``;``<command>
’.
HIST_ALLOW_CLOBBER
Add ‘|
’ to output redirections in the history. This allows history
references to clobber files even when CLOBBER
is unset.
HIST_BEEP
<D>
Beep in ZLE when a widget attempts to access a history entry which isn’t there.
HIST_EXPIRE_DUPS_FIRST
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 HISTSIZE
to a larger number than
SAVEHIST
in order to give you some room for the duplicated events,
otherwise this option will behave just like HIST_IGNORE_ALL_DUPS
once
the history fills up with unique events.
HIST_FCNTL_LOCK
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 fcntl
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.
HIST_FIND_NO_DUPS
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.
HIST_IGNORE_ALL_DUPS
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).
HIST_IGNORE_DUPS
(-h
)
Do not enter command lines into the history list if they are duplicates of the previous event.
HIST_IGNORE_SPACE
(-g
)
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.
HIST_LEX_WORDS
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.
HIST_NO_FUNCTIONS
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.
HIST_NO_STORE
Remove the history
(fc -l
) 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.
HIST_REDUCE_BLANKS
Remove superfluous blanks from each command line being added to the history list.
HIST_SAVE_BY_COPY
<D>
When the history file is re-written, we normally write out a copy of the
file named $HISTFILE.new
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.
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.
HIST_SAVE_NO_DUPS
When writing out the history file, older commands that duplicate newer ones are omitted.
HIST_VERIFY
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.
INC_APPEND_HISTORY
This option works like APPEND_HISTORY
except that new history lines
are added to the $HISTFILE
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 $SAVEHIST
(see also the
HIST_SAVE_BY_COPY
option).
INC_APPEND_HISTORY_TIME
This option is a variant of INC_APPEND_HISTORY
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 EXTENDED_HISTORY
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.
This option is only useful if INC_APPEND_HISTORY
and SHARE_HISTORY
are turned off. The three options should be considered mutually
exclusive.
SHARE_HISTORY
<K>
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 INC_APPEND_HISTORY
, which should be turned
off if this option is in effect). The history lines are also output with
timestamps ala EXTENDED_HISTORY
(which makes it easier to find the
spot where we left off reading the file after it gets re-written).
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.
If you find that you want more control over when commands get imported,
you may wish to turn SHARE_HISTORY
off, INC_APPEND_HISTORY
or
INC_APPEND_HISTORY_TIME
(see above) on, and then manually import
commands whenever you need them using ‘fc -RI
’.
16.2.5 Initialisation
ALL_EXPORT
(-a
, ksh: -a
)
All parameters subsequently defined are automatically exported.
GLOBAL_EXPORT
<Z>
If this option is set, passing the -x
flag to the builtins declare
,
float
, integer
, readonly
and typeset
(but not local
) will also
set the -g
flag; hence parameters exported to the environment will not
be made local to the enclosing function, unless they were already or the
flag +g
is given explicitly. If the option is unset, exported
parameters will be made local in just the same way as any other
parameter.
This option is set by default for backward compatibility; it is not
recommended that its behaviour be relied upon. Note that the builtin
export
always sets both the -x
and -g
flags, and hence its effect
extends beyond the scope of the enclosing function; this is the
GLOBAL_RCS
(-d
) <D>
If this option is unset, the startup files /etc/zprofile
,
/etc/zshrc
, /etc/zlogin
and /etc/zlogout
will not be run. It can
be disabled and re-enabled at any time, including inside local startup
files (.zshrc
, etc.).
RCS
(+f
) <D>
After /etc/zshenv
is sourced on startup, source the .zshenv
,
/etc/zprofile
, .zprofile
, /etc/zshrc
, .zshrc
, /etc/zlogin
,
.zlogin
, and .zlogout
files, as described in
Files. If this option is unset, the /etc/zshenv
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.
16.2.6 Input/Output
ALIASES
<D>
Expand aliases.
CLOBBER
(+C
, ksh: +C
) <D>
Allows ‘>
’ redirection to truncate existing files. Otherwise ‘>!
’ or
‘>|
’ must be used to truncate a file.
If the option is not set, and the option APPEND_CREATE
is also not
set, ‘>>!
’ or ‘>>|
’ must be used to create a file. If either option
is set, ‘>>
’ may be used.
CORRECT
(-0
)
Try to correct the spelling of commands. Note that, when the
HASH_LIST_ALL
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.
The shell variable CORRECT_IGNORE
may be set to a pattern to match
words that will never be offered as corrections.
CORRECT_ALL
(-O
)
Try to correct the spelling of all arguments in a line.
The shell variable CORRECT_IGNORE_FILE
may be set to a pattern to
match file names that will never be offered as corrections.
DVORAK
Use the Dvorak keyboard instead of the standard qwerty keyboard as a
basis for examining spelling mistakes for the CORRECT
and
CORRECT_ALL
options and the spell-word
editor command.
FLOW_CONTROL
<D>
If this option is unset, output flow control via start/stop characters (usually assigned to ^S/^Q) is disabled in the shell’s editor.
IGNORE_EOF
(-7
)
Do not exit on end-of-file. Require the use of exit
or logout
instead. However, ten consecutive EOFs will cause the shell to exit
anyway, to avoid the shell hanging if its tty goes away.
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.
INTERACTIVE_COMMENTS
(-k
) <K> <S>
Allow comments even in interactive shells.
HASH_CMDS
<D>
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 CORRECT
is set, commands whose names do not
appear in reporting them as spelling errors.
HASH_DIRS
<D>
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 HASH_CMDS
nor CORRECT
is set.
HASH_EXECUTABLES_ONLY
When hashing commands because of HASH_CMDS
, 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.
MAIL_WARNING
(-U
)
Print a warning message if a mail file has been accessed since the shell last checked.
PATH_DIRS
(-Q
)
Perform a path search even on command names with slashes in them. Thus
if ‘/usr/local/bin
’ is in the user’s path, and he or she types
‘X11/xinit
’, the command ‘/usr/local/bin/X11/xinit
’ will be
executed (assuming it exists). Commands explicitly beginning with ‘/
’,
‘./
’ or ‘../
’ are not subject to the path search. This also applies
to the ‘.
’ and source
builtins.
Note that subdirectories of the current directory are always searched
for indicated by this option, and regardless of whether ‘.
’ or the
current directory appear in the command search path.
PATH_SCRIPT
<K> <S>
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 Invocation.
PRINT_EIGHT_BIT
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)).
PRINT_EXIT_VALUE
(-1
)
Print the exit value of programs with non-zero exit status. This is only available at the command line in interactive shells.
RC_QUOTES
Allow the character sequence ‘’’
’ to signify a single quote within
singly quoted strings. Note this does not apply in quoted strings using
the format $’``...``’
, where a backslashed single quote can be used.
RM_STAR_SILENT
(-H
) <K> <S>
Do not query the user before executing ‘rm *
’ or ‘rm path/*
’.
RM_STAR_WAIT
If querying the user before executing ‘rm *
’ or ‘rm path/*
’, 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 ‘*
’ in ZLE (with tab).
SHORT_LOOPS
<C> <Z>
Allow the short forms of for
, repeat
, select
, if
, and function
constructs.
SUN_KEYBOARD_HACK
(-L
)
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
KEYBOARD_HACK
lets you choose the character to be removed.
16.2.7 Job Control
AUTO_CONTINUE
with the disown
builtin command are automatically sent a CONT
signal
to make them running.
AUTO_RESUME
(-W
)
Treat single word simple commands without redirection as candidates for resumption of an existing job.
BG_NICE
(-6
) <C> <Z>
Run all background jobs at a lower priority. This option is set by default.
CHECK_JOBS
<Z>
Report the status of background and suspended jobs before exiting a
shell with job control; a second attempt to exit the shell will succeed.
NO_CHECK_JOBS
is best used only in combination with NO_HUP
, else
such jobs will be killed automatically.
The check is omitted if the commands run from the previous command line
included a ‘jobs
’ command, since it is assumed the user is aware that
there are background or suspended jobs. A ‘jobs
’ command run from one
of the hook functions defined in the section Special Functions in
Functions is not counted for this purpose.
CHECK_RUNNING_JOBS
<Z>
Check for both running and suspended jobs when CHECK_JOBS
is enabled.
When this option is disabled, zsh checks only for suspended jobs, which
matches the default behavior of bash.
This option has no effect unless CHECK_JOBS
is set.
HUP
<Z>
Send the HUP
signal to running jobs when the shell exits.
LONG_LIST_JOBS
(-R
)
Print job notifications in the long format by default.
MONITOR
(-m
, ksh: -m
)
Allow job control. Set by default in interactive shells.
NOTIFY
(-5
, ksh: -b
) <Z>
Report the status of background jobs immediately, rather than waiting until just before printing a prompt.
POSIX_JOBS
<K> <S>
This option makes job control more compliant with the POSIX standard.
When the option is not set, the MONITOR
option is unset on entry to
subshells, so that job control is no longer active. When the option is
set, the MONITOR
option and job control remain active in the subshell,
but note that the subshell has no access to jobs in the parent shell.
When the option is not set, jobs put in the background or foreground
with bg
or fg
are displayed with the same information that would be
reported by jobs
. When the option is set, only the text is printed.
The output from jobs
itself is not affected by the option.
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 jobs
is empty until a job is
started within the subshell.
In previous versions of the shell, it was necessary to enable
POSIX_JOBS
in order for the builtin command wait
to return the
status of background jobs that had already exited. This is no longer the
case.
16.2.8 Prompting
PROMPT_BANG
<K>
If set, ‘!
’ is treated specially in prompt expansion. See Prompt
Expansion.
PROMPT_CR
(+V
) <D>
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.
PROMPT_SP
<D>
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 PROMPT_CR
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).
When a partial line is preserved, by default you will see an
inverse+bold character at the end of the partial line: a ‘%
’ for a
normal user or a ‘#
’ for root. If set, the shell parameter
PROMPT_EOL_MARK
can be used to customize how the end of partial lines
are shown.
NOTE: if the PROMPT_CR
option is not set, enabling this option will
have no effect. This option is on by default.
PROMPT_PERCENT
<C> <Z>
If set, ‘%
’ is treated specially in prompt expansion. See Prompt
Expansion.
PROMPT_SUBST
<K> <S>
If set, parameter expansion, command substitution and arithmetic expansion are performed in prompts. Substitutions within prompts do not affect the command status.
TRANSIENT_RPROMPT
Remove any right prompt from display when accepting a command line. This may be useful with terminals with other cut/paste methods.
16.2.9 Scripts and Functions
ALIAS_FUNC_DEF
<S>
By default, zsh does not allow the definition of functions using the
‘name
()
’ syntax if name
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.
When this option is set, aliases can be used for defining functions.
For example, consider the following definitions as they might occur in a startup file.
alias foo=bar
foo() {
print This probably does not do what you expect.
}
Here, foo
is expanded as an alias to bar
before the ()
is
encountered, so the function defined would be named bar
. By default
this is instead an error in native mode. Note that quoting any part of
the function name, or using the keyword function
, avoids the problem,
so is recommended when the function name can also be an alias.
C_BASES
Output hexadecimal numbers in the standard C format, for example
‘0xFF
’ instead of the usual ‘16#FF
’. If the option
OCTAL_ZEROES
is also set (it is not by default), octal numbers will be
treated similarly and hence appear as ‘077
’ instead of ‘8#77
’. 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 C_BASES
.
C_PRECEDENCES
This alters the precedence of arithmetic operators to be more like C and other programming languages; Arithmetic Evaluation has an explicit list.
DEBUG_BEFORE_CMD
<D>
Run the DEBUG
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.
ERR_EXIT
(-e
, ksh: -e
)
If a command has a non-zero exit status, execute the ZERR
trap, if
set, and exit. This is disabled while running initialization scripts.
The behaviour is also disabled inside DEBUG
traps. In this case the
option is handled specially: it is unset on entry to the trap. If the
option DEBUG_BEFORE_CMD
is set, as it is by default, and the option
ERR_EXIT
is found to have been set on exit, then the command for which
the DEBUG
trap is being executed is skipped. The option is restored
after the trap exits.
Non-zero status in a command list containing &&
or ||
is ignored for
commands not at the end of the list. Hence
false && true
does not trigger exit.
Exiting due to ERR_EXIT
has certain interactions with asynchronous
jobs noted in Jobs &
Signals.
ERR_RETURN
If a command has a non-zero exit status, return immediately from the
enclosing function. The logic is similar to that for ERR_EXIT
, except
that an implicit return
statement is executed instead of an exit
.
This will trigger an exit at the outermost level of a non-interactive
script.
Normally this option inherits the behaviour of ERR_EXIT
that code
followed by ‘&&
’ ‘||
’ does not trigger a return. Hence in the
following:
summit || true
no return is forced as the combined effect always has a zero return status.
Note. however, that if summit
in the above example is itself a
function, code inside it is considered separately: it may force a return
from summit
(assuming the option remains set within summit
), but not
from the enclosing context. This behaviour is different from ERR_EXIT
which is unaffected by function scope.
EVAL_LINENO
<Z>
If set, line numbers of expressions evaluated using the builtin eval
are tracked separately of the enclosing environment. This applies both
to the parameter LINENO
and the line number output by the prompt
escape %i
. If the option is set, the prompt escape %N
will output
the string ‘(eval)
’ instead of the script or function name as an
indication. (The two prompt escapes are typically used in the parameter
PS4
to be output when the option XTRACE
is set.) If EVAL_LINENO
is
unset, the line number of the surrounding script or function is retained
during the evaluation.
EXEC
(+n
, ksh: +n
) <D>
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 ‘-n
’ is supplied to the shell at
startup.
FUNCTION_ARGZERO
<C> <Z>
When executing a shell function or sourcing a script, set $0
temporarily to the name of the function/script. Note that toggling
FUNCTION_ARGZERO
from on to off (or off to on) does not change the
current value of $0
. Only the state upon entry to the function or
script has an effect. Compare POSIX_ARGZERO
.
LOCAL_LOOPS
When this option is not set, the effect of break
and continue
commands may propagate outside function scope, affecting loops in
calling functions. When the option is set in a calling function, a
break
or a continue
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.
LOCAL_OPTIONS
<K>
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 PRIVILEGED
and RESTRICTED
. Otherwise, only this option, and the LOCAL_LOOPS
,
XTRACE
and PRINT_EXIT_VALUE
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 ‘emulate -L zsh
’; the -L
activates LOCAL_OPTIONS
.
LOCAL_PATTERNS
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 ‘disable -p
’, is restored to what it was when the function was entered. The
behaviour of this option is similar to the effect of LOCAL_OPTIONS
on
options; hence ‘emulate -L sh
’ (or indeed any other emulation with the
-L
option) activates LOCAL_PATTERNS
.
LOCAL_TRAPS
<K>
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 prior to
altering the trap behaviour in a function; unlike LOCAL_OPTIONS
, 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,
unsetopt localtraps
trap - INT
fn() { setopt localtraps; trap '' INT; sleep 3; }
will restore normal handling of SIGINT
after the function exits.
MULTI_FUNC_DEF
<Z>
Allow definitions of multiple functions at once in the form ‘fn1 fn2``...``()
’; if the option is not set, this causes a parse error.
Definition of multiple functions with the function
keyword is always
allowed. Multiple function definitions are not often used and can cause
obscure errors.
MULTIOS
<Z>
Perform implicit tees or cats when multiple redirections are attempted (see Redirection).
OCTAL_ZEROES
<S>
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.
Sequences of digits indicating a numeric base such as the ‘08
’
component in ‘08#77
’ are always interpreted as decimal, regardless of
leading zeroes.
PIPE_FAIL
By default, when a pipeline exits the exit status recorded by the shell
and returned by the shell variable $?
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.
SOURCE_TRACE
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
XTRACE
option, with the message <sourcetrace>
. A file may be loaded
by the shell itself when it starts up and shuts down (Startup/Shutdown Files
) or by the use of the ‘source
’ and ‘dot
’ builtin commands.
TYPESET_SILENT
If this is unset, executing any of the ‘typeset
’ 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 ‘-m
’ option. The option ‘-p
’ is available whether or not
the option is set.
VERBOSE
(-v
, ksh: -v
)
Print shell input lines as they are read.
XTRACE
(-x
, ksh: -x
)
Print commands and their arguments as they are executed. The output is
preceded by the value of $PS4
, formatted as described in Prompt
Expansion.
16.2.10 Shell Emulation
APPEND_CREATE
<K> <S>
This option only applies when NO_CLOBBER
(-C
) is in effect.
If this option is not set, the shell will report an error when a append
redirection (>>
) is used on a file that does not already exists (the
traditional zsh behaviour of NO_CLOBBER
). If the option is set, no
error is reported (POSIX behaviour).
BASH_REMATCH
When set, matches performed with the =~
operator will set the
BASH_REMATCH
array variable, instead of the default MATCH
and
match
variables. The first element of the BASH_REMATCH
array will
contain the entire matched text and subsequent elements will contain
extracted substrings. This option makes more sense when KSH_ARRAYS
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 MATCH
variable contains the entire matched text and the match
array variable
contains substrings.
BSD_ECHO
<S>
Make the echo
builtin compatible with the BSD man page echo(1)
command. This disables backslashed escape sequences in echo strings
unless the -e
option is specified.
CONTINUE_ON_ERROR
If a fatal error is encountered (see Errors), 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.
CSH_JUNKIE_HISTORY
<C>
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.
CSH_JUNKIE_LOOPS
<C>
Allow loop bodies to take the form ‘list``; end
’ instead of ‘ do ``list``; done
’.
CSH_JUNKIE_QUOTES
<C>
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 ‘$
’, ‘‘
’ or ‘"
’ (and
‘\
’ itself no longer needs escaping). Command substitutions are
only expanded once, and cannot be nested.
CSH_NULLCMD
<C>
Do not use the values of NULLCMD
and READNULLCMD
when running
redirections with no command. This make such redirections fail (see
Redirection).
KSH_ARRAYS
<K> <S>
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 (‘${path[2]}
’ rather than
just ‘$path[2]
’) or to apply modifiers to any parameter (‘${PWD:h}
’
rather than ‘$PWD:h
’).
KSH_AUTOLOAD
<K> <S>
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.)
KSH_OPTION_PRINT
<K>
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.
KSH_TYPESET
This option is now obsolete: a better appropximation to the behaviour of
other shells is obtained with the reserved word interface to declare
,
export
, float
, integer
, local
, readonly
and typeset
. Note
that the option is only applied when the reserved word interface is
not in use.
Alters the way arguments to the typeset
family of commands, including
declare
, export
, float
, integer
, local
and readonly
, 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.
KSH_ZERO_SUBSCRIPT
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 KSH_ARRAYS
is also set.
If neither this option nor KSH_ARRAYS
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
KSH_ZERO_SUBSCRIPT
is not set,
array[0]=(element)
is an error, while
array[0,1]=(element)
is not and will replace the first element of the array.
This option is for compatibility with older versions of the shell and is not recommended in new code.
POSIX_ALIASES
<K> <S>
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 Reserved Words.
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 ‘zsh -c
’, or even ‘zsh -o posixaliases -c
’, 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.
POSIX_ARGZERO
This option may be used to temporarily disable FUNCTION_ARGZERO
and
thereby restore the value of $0
to the name used to invoke the shell
(or as set by the -c
command line option). For compatibility with
previous versions of the shell, emulations use NO_FUNCTION_ARGZERO
instead of POSIX_ARGZERO
, which may result in unexpected scoping of
$0
if the emulation mode is changed inside a function or script. To
avoid this, explicitly enable POSIX_ARGZERO
in the emulate
command:
emulate sh -o POSIX_ARGZERO
Note that NO_POSIX_ARGZERO
has no effect unless FUNCTION_ARGZERO
was
already enabled upon entry to the function or script.
POSIX_BUILTINS
<K> <S>
When this option is set the command
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 command
builtin.
Special builtins are .
, :
, break
, continue
, declare
, eval
,
exit
, export
, integer
, local
, readonly
, return
, set
,
shift
, source
, times
, trap
and unset
.
In addition, various error conditions associated with the above builtins
or exec
cause a non-interactive shell to exit and an interactive shell
to return to its top-level processing.
Furthermore, functions and shell builtins are not executed after an
exec
prefix; the command to be executed must be an external command
found in the path.
Furthermore, the getopts
builtin behaves in a POSIX-compatible fashion
in that the associated variable OPTIND
is not made local to functions.
Moreover, the warning and special exit code from [[ -o ``non_existent_option`` ]]
are suppressed.
POSIX_IDENTIFIERS
<K> <S>
When this option is set, only the ASCII characters a
to z
, A
to
Z
, 0
to 9
and _
may be used in identifiers (names of shell
parameters and modules).
In addition, setting this option limits the effect of parameter
substitution with no braces, so that the expression $#
is treated as
the parameter $#
even if followed by a valid parameter name. When it
is unset, zsh allows expressions of the form $#``name
to refer to the
length of $``name
, even for special variables, for example in
expressions such as $#-
and $#*
.
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 ‘unset t; (( t = 3 ))
’.
without POSIX_IDENTIFIERS
set t
has integer type, while with it set
it has scalar type.
When the option is unset and multibyte character support is enabled
(i.e. it is compiled in and the option MULTIBYTE
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 variable``=``value
has already been
parsed as a command rather than an assignment.
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.
POSIX_STRINGS
<K> <S>
This option affects processing of quoted strings. Currently it only affects the behaviour of null characters, i.e. character 0 in the
When this option is not set, null characters embedded within strings of
the form $’``...``’
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.
When this option is set, the $’``...``’
expression is truncated at the
null character. Note that remaining parts of the same string beyond the
termination of the quotes are not truncated.
For example, the command line argument a$’b\0c’d
is treated with the
option off as the characters a
, b
, null, c
, d
, and with the
option on as the characters a
, b
, d
.
POSIX_TRAPS
<K> <S>
When this option is set, the usual zsh behaviour of executing traps for
EXIT
on exit from shell functions is suppressed. In that case,
manipulating EXIT
traps always alters the global trap for exiting the
shell; the LOCAL_TRAPS
option is ignored for the EXIT
trap.
Furthermore, a return
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.
SH_FILE_EXPANSION
<K> <S>
Perform filename expansion (e.g., ~
expansion) before parameter
expansion, command substitution, arithmetic expansion and brace
expansion. If this option is unset, it is performed after brace
expansion, so things like ‘~$USERNAME
’ and ‘~{pfalstad,rc}
’ will
work.
SH_NULLCMD
<K> <S>
Do not use the values of NULLCMD
and READNULLCMD
when doing
redirections, use ‘:
’ instead (see
Redirection).
SH_OPTION_LETTERS
<K> <S>
If this option is set the shell tries to interpret single letter options
(which are used with set
and setopt
) like ksh does. This also
affects the value of the -
special parameter.
SH_WORD_SPLIT
(-y
) <K> <S>
Causes field splitting to be performed on unquoted parameter expansions. Note that this option has nothing to do with word splitting. (See Parameter Expansion.)
TRAPS_ASYNC
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.
16.2.11 Shell State
INTERACTIVE
(-i
, ksh: -i
)
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 SHIN_STDIN
.) 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.
LOGIN
(-l
, ksh: -l
)
This is a login shell. If this option is not explicitly set, the shell
becomes a login shell if the first character of the argv[0]
passed to
the shell is a ‘-
’.
PRIVILEGED
(-p
, ksh: -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 -p
option to zsh so that it takes effect during startup.
#!/bin/zsh -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:
unsetopt privileged || exit
The PRIVILEGED
option disables sourcing user startup files. If zsh is
invoked as ‘sh
’ or ‘ksh
’ with this option set, /etc/suid_profile
is sourced (after /etc/profile
on interactive shells). Sourcing
~/.profile
is disabled and the contents of the ENV
variable is
ignored. This option cannot be changed using the -m
option of setopt
and unsetopt
, and changing it inside a function always changes it
globally regardless of the LOCAL_OPTIONS
option.
RESTRICTED
(-r
)
Enables restricted mode. This option cannot be changed using unsetopt
,
and setting it inside a function always changes it globally regardless
of the LOCAL_OPTIONS
option. See Restricted
Shell.
SHIN_STDIN
(-s
, ksh: -s
)
Commands are being read from the standard input. Commands are read from
standard input if no command is specified with -c
and no file of
commands is specified. If SHIN_STDIN
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
actually 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.
SINGLE_COMMAND
(-t
, ksh: -t
)
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 INTERACTIVE
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.
16.2.12 Zle
BEEP
(+B
) <D>
Beep on error in ZLE.
COMBINING_CHARS
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.
If this option is set, the pattern test [[:WORD:]]
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.
EMACS
If ZLE is loaded, turning on this option has the equivalent effect of
‘bindkey -e
’. 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; bindkey
is
the recommended interface.
OVERSTRIKE
Start up the line editor in overstrike mode.
SINGLE_LINE_ZLE
(-M
) <K>
Use single-line command line editing instead of multi-line.
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.
VI
If ZLE is loaded, turning on this option has the equivalent effect of
‘bindkey -v
’. 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; bindkey
is
the recommended interface.
ZLE
(-Z
)
Use the zsh line editor. Set by default in interactive shells connected to a terminal.
16.3 Option Aliases
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.
BRACE_EXPAND
NO_IGNORE_BRACES
(ksh and bash compatibility)
DOT_GLOB
GLOB_DOTS
(bash compatibility)
HASH_ALL
HASH_CMDS
(bash compatibility)
HIST_APPEND
APPEND_HISTORY
(bash compatibility)
HIST_EXPAND
BANG_HIST
(bash compatibility)
LOG
NO_HIST_NO_FUNCTIONS
(ksh compatibility)
MAIL_WARN
MAIL_WARNING
(bash compatibility)
ONE_CMD
SINGLE_COMMAND
(bash compatibility)
PHYSICAL
CHASE_LINKS
(ksh and bash compatibility)
PROMPT_VARS
PROMPT_SUBST
(bash compatibility)
STDIN
SHIN_STDIN
(ksh compatibility)
TRACK_ALL
HASH_CMDS
(ksh compatibility)
16.4 Single Letter Options
16.4.1 Default set
-
-0
CORRECT -
-1
PRINT_EXIT_VALUE -
-2
*NO_*BAD_PATTERN -
-3
*NO_*NOMATCH -
-4
GLOB_DOTS -
-5
NOTIFY -
-6
BG_NICE -
-7
IGNORE_EOF -
-8
MARK_DIRS -
-9
AUTO_LIST -
-B
*NO_*BEEP -
-C
*NO_*CLOBBER -
-D
PUSHD_TO_HOME -
-E
PUSHD_SILENT -
-F
*NO_*GLOB -
-G
NULL_GLOB -
-H
RM_STAR_SILENT -
-I
IGNORE_BRACES -
-J
AUTO_CD -
-K
*NO_*BANG_HIST -
-L
SUN_KEYBOARD_HACK -
-M
SINGLE_LINE_ZLE -
-N
AUTO_PUSHD -
-O
CORRECT_ALL -
-P
RC_EXPAND_PARAM -
-Q
PATH_DIRS -
-R
LONG_LIST_JOBS -
-S
REC_EXACT -
-T
CDABLE_VARS -
-U
MAIL_WARNING -
-V
*NO_*PROMPT_CR -
-W
AUTO_RESUME -
-X
LIST_TYPES -
-Y
MENU_COMPLETE -
-Z
ZLE -
-a
ALL_EXPORT -
-e
ERR_EXIT -
-f
*NO_*RCS -
-g
HIST_IGNORE_SPACE -
-h
HIST_IGNORE_DUPS -
-i
INTERACTIVE -
-k
INTERACTIVE_COMMENTS -
-l
LOGIN -
-m
MONITOR -
-n
*NO_*EXEC -
-p
PRIVILEGED -
-r
RESTRICTED -
-s
SHIN_STDIN -
-t
SINGLE_COMMAND -
-u
*NO_*UNSET -
-v
VERBOSE -
-w
CHASE_LINKS -
-x
XTRACE -
-y
SH_WORD_SPLIT
16.4.2 sh/ksh emulation set
-
-C
*NO_*CLOBBER -
-T
TRAPS_ASYNC -
-X
MARK_DIRS -
-a
ALL_EXPORT -
-b
NOTIFY -
-e
ERR_EXIT -
-f
*NO_*GLOB -
-i
INTERACTIVE -
-l
LOGIN -
-m
MONITOR -
-n
*NO_*EXEC -
-p
PRIVILEGED -
-r
RESTRICTED -
-s
SHIN_STDIN -
-t
SINGLE_COMMAND -
-u
*NO_*UNSET -
-v
VERBOSE -
-x
XTRACE
16.4.3 Also note
-
-A
Used byset
for setting arrays -
-b
Used on the command line to specify end of option processing -
-c
Used on the command line to specify a single command -
-m
Used bysetopt
for pattern-matching option setting -
-o
Used in all places to allow use of long option names -
-s
Used byset
to sort positional parameters
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
17 Shell Builtin Commands
Some shell builtin commands take options as described in individual
entries; these are often referred to in the list below as ‘flags
’ to
avoid confusion with shell options, which may also have an effect on the
behaviour of builtin commands. In this introductory section, ‘option
’
always has the meaning of an option to a command that should be familiar
to most command line users.
Typically, options are single letters preceded by a hyphen (-
).
Options that take an argument accept it either immediately following the
option letter or after white space, for example ‘print -C3 {1..9}
’ or
‘print -C 3 {1..9}
’ 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 ‘print -rca – *
’ and ‘print -r -c -a – *
’ are
equivalent.
Some shell builtin commands also take options that begin with ‘+
’
instead of ‘-
’. The list below makes clear which commands these are.
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.
All builtin commands other than ‘echo
’ and precommand modifiers, even
those that have no options, can be given the argument ‘-``-
’ 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 ‘-
’. For historical
reasons, most builtin commands (including ‘echo
’) also recognize a
single ‘-
’ in a separate word for this purpose; note that this is less
standard and use of ‘-``-
’ is recommended.
-
-
simple command
See Precommand Modifiers. -
.
file
[arg
... ]
Read commands fromfile
and execute them in the current shell environment.If
file
does not contain a slash, or ifPATH_DIRS
is set, the shell looks in the components of$path
to find the directory containingfile
. Files in the current directory are not read unless ‘.
’ appears somewhere in$path
. If a file named ‘file``.zwc
’ is found, is newer thanfile
, and is the compiled form (created with thezcompile
builtin) offile
, then commands are read from that file instead offile
.If any arguments
arg
are given, they become the positional parameters; the old positional parameters are restored when thefile
is done executing. However, if no arguments are given, the positional parameters remain those of the calling context, and no restoring is done.If
file
was not found the return status is 127; iffile
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. -
:
[arg
... ]
This command does nothing, although normal argument expansions is performed which may have effects on shell parameters. A zero exit status is returned. -
alias
[ {+
|-
}gmrsL
] [name
[=``value
] ... ]
For eachname
with a correspondingvalue
, define an alias with that value. A trailing space invalue
causes the next word to be checked for alias expansion. If the-g
flag is present, define a global alias; global aliases are expanded even if they do not occur in command position.If the
-s
flag is present, define a suffix alias: if the command word on a command line is in the form ‘text``.``name
’, wheretext
is any non-empty string, it is replaced by the text ‘value
text``.``name
’. Note thatname
is treated as a literal string, not a pattern. A trailing space invalue
is not special in this case. For example,alias -s ps='gv --'
will cause the command ‘
*.ps
’ to be expanded to ‘gv – *.ps
’. As alias expansion is carried out earlier than globbing, the ‘*.ps
’ 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 commandps
) and the two sets are never listed together.For each
name
with novalue
, print the value ofname
, if any. With no arguments, print all currently defined aliases other than suffix aliases. If the-m
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-g
,-r
or-s
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 ‘+
’ instead of ‘-
’, or ending the option list with a single ‘+
’, prevents the values of the aliases from being printed.If the
-L
flag is present, then print each status is nonzero if aname
(with novalue
) is given for which no alias has been defined.For more on aliases, include common problems, see Aliasing.
-
autoload
[ {+
|-
}RTUXdkmrtWz
] [-w
] [name
... ]
See the section ‘Autoloading Functions’ in Functions for full details. The
fpath
parameter will be searched to find the function definition when the function is first referenced.If
name
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-d
is given, searching for the function defaults to$fpath
. If a function is loaded by absolute path, any functions loaded from it that are marked forautoload
without an absolute path have the load path of the parent function temporarily prepended to$fpath
.If the option
-r
or-R
is given, the function is searched for immediately and the location is recorded internally for use when the function is executed; a relative path is expanded using the value of$PWD
. This protects against a change to$fpath
after the call toautoload
. With-r
, if the function is not found, it is silently left unresolved until execution; with-R
, an error message is printed and command processing aborted immediately the search fails, i.e. at theautoload
command rather than at function execution..The flag
-X
may be used only inside a shell function. It causes the calling function to be marked for autoloading and then immediately loaded and executed, with the current array of positional parameters as arguments. This replaces the previous definition of the function. If no function definition is found, an error is printed and the function remains undefined and marked for autoloading. If an argument is given, it is used as a directory (i.e. it does not include the name of the function) in which the function is to be found; this may be combined with the-d
option to allow the function search to default to$fpath
if it is not in the given location.The flag
+X
attempts to load eachname
as an autoloaded function, but does not execute it. The exit status is zero (success) if the function was not previously defined and a definition for it was found. This does not 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-m
flag is also given eachname
is treated as a pattern and all functions already marked for autoload that match the pattern are loaded.With the
-t
flag, turn on execution tracing; with-T
, 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.With the
-U
flag, alias expansion is suppressed when the function is loaded.With the
-w
flag, thename
s are taken as names of files compiled with thezcompile
builtin, and all functions defined in them are marked for autoloading.The flags
-z
and-k
mark the function to be autoloaded using the zsh or ksh style, as if the optionKSH_AUTOLOAD
were unset or were set, respectively. The flags override the setting of the option at the time the function is loaded.Note that the
autoload
command makes no attempt to ensure the shell options set during the loading or execution of the file have any particular value. For this, theemulate
command can be used:emulate zsh -c 'autoload -Uz func'
arranges that when
func
is loaded the shell is in nativezsh
emulation, and this emulation is also applied whenfunc
is run.Some of the functions of
autoload
are also provided byfunctions -u
orfunctions -U
, butautoload
is a more comprehensive interface. -
bg
[job
... ]
job
...&
Put each specifiedjob
in the background, or the current job if none is specified. -
bindkey
See Zle Builtins. -
break
[n
]
Exit from an enclosingfor
,while
,until
,select
orrepeat
loop. If an arithmetic expressionn
is specified, then breakn
levels instead of just one. -
builtin
name
[args
... ]
Executes the builtinname
, with the givenargs
. -
bye
Same asexit
. -
cap
See The zsh/cap Module. -
cd
[-qsLP
] [arg
]
cd
[-qsLP
]old
new
cd
[-qsLP
] {+
|-
}n
Change the current directory. In the first form, change the current directory toarg
, or to the value of$HOME
ifarg
is not specified. Ifarg
is ‘-
’, change to the previous directory.Otherwise, if
arg
begins with a slash, attempt to change to the directory given byarg
.If
arg
does not begin with a slash, the behaviour depends on whether the current directory ‘.
’ occurs in the list of directories contained in the shell parametercdpath
. If it does not, first attempt to change to the directoryarg
under the current directory, and if that fails butcdpath
is set and contains at least one element attempt to change to the directoryarg
under each component ofcdpath
in turn until successful. If ‘.
’ occurs incdpath
, thencdpath
is searched strictly in order so that ‘.
’ is only tried at the appropriate point.The order of testing
cdpath
is modified if the optionPOSIX_CD
is set, as described in the documentation for the option.If no directory is found, the option
CDABLE_VARS
is set, and a parameter namedarg
exists whose value begins with a slash, treat its value as the directory. In that case, the parameter is added to the namedThe second form of
cd
substitutes the stringnew
for the stringold
in the name of the current directory, and tries to change to this new directory.The third form of
cd
extracts an entry from the directory stack, and changes to that directory. An argument of the form ‘+``n
’ identifies a stack entry by counting from the left of the list shown by thedirs
command, starting with zero. An argument of the form ‘-``n
’ counts from the right. If thePUSHD_MINUS
option is set, the meanings of ‘+
’ and ‘-
’ in this context are swapped. If thePOSIX_CD
option is set, this form ofcd
is not recognised and will be interpreted as the first form.If the
-q
(quiet) option is specified, the hook functionchpwd
and the functions in the arraychpwd_functions
are not called. This is useful for calls tocd
that do not change the environment seen by an interactive user.If the
-s
option is specified,cd
refuses to change the current directory if the given pathname contains symlinks. If the-P
option is given or theCHASE_LINKS
option is set, symbolic links are resolved to their true values. If the-L
option is given symbolic links are retained in the directory (and not resolved) regardless of the state of theCHASE_LINKS
option. -
chdir
Same ascd
. -
clone
See The zsh/clone Module. -
command
[-pvV
]simple command
The simple command argument is taken as an external command instead of a function or builtin and is executed. If thePOSIX_BUILTINS
option is set, builtins will also be executed but certain special properties of them are suppressed. The-p
flag causes a default path to be searched instead of that in$path
. With the-v
flag,command
is similar towhence
and with-V
, it is equivalent towhence -v
.See also Precommand Modifiers.
-
comparguments
See The zsh/computil Module. -
compcall
See The zsh/compctl Module. -
compctl
See The zsh/compctl Module. -
compdescribe
See The zsh/computil Module. -
compfiles
See The zsh/computil Module. -
compgroups
See The zsh/computil Module. -
compquote
See The zsh/computil Module. -
comptags
See The zsh/computil Module. -
comptry
See The zsh/computil Module. -
compvalues
See The zsh/computil Module. -
continue
[n
]
Resume the next iteration of the enclosingfor
,while
,until
,select
orrepeat
loop. If an arithmetic expressionn
is specified, break out ofn
-1 loops and resume at then
th enclosing loop. -
declare
Same astypeset
. -
dirs
[-c
] [arg
... ]
dirs
[-lpv
]
With no arguments, print the contents of the directory stack. Directories are added to this stack with thepushd
command, and removed with thecd
orpopd
commands. If arguments are specified, load them onto the directory stack, replacing anything that was there, and push the current directory onto the stack.-
-c
clear the directory stack. -
-l
print directory names in full instead of using of using~
expressions (Filename Expansion). -
-p
print directory entries one per line. -
-v
number the directories in the stack when printing.
-
-
disable
[-afmprs
]name
...
’?’
The pattern character?
wherever it occurs, including when preceding a parenthesis withKSH_GLOB
. -
’*’
The pattern character*
wherever it occurs, including recursive globbing and when preceding a parenthesis withKSH_GLOB
. -
’[’
Character classes. -
’<’
(NO_SH_GLOB
)
Numeric ranges. -
’|’
(NO_SH_GLOB
)
Alternation in grouped patterns, case statements, or KSH_GLOB parenthesised expressions. -
’(’
(NO_SH_GLOB
)
Grouping using single parentheses. Disabling this does not disable the use of parentheses forKSH_GLOB
where they are introduced by a special character, nor for glob qualifiers (use ‘setopt NO_BARE_GLOB_QUAL
’ to disable glob qualifiers that use parentheses only). -
’~’
(EXTENDED_GLOB
)
Exclusion in the formA``~``B
. -
’^’
(EXTENDED_GLOB
)
Exclusion in the formA``^``B
. -
’#’
(EXTENDED_GLOB
)
The pattern character#
wherever it occurs, both for repetition of a previous pattern and for indicating globbing flags. -
’?(’
(KSH_GLOB
)
The grouping form?(``...``)
. Note this is also disabled if’?’
is disabled. -
’*(’
(KSH_GLOB
)
The grouping form*(``...``)
. Note this is also disabled if’*’
is disabled. -
’+(’
(KSH_GLOB
)
The grouping form+(``...``)
. -
’!(’
(KSH_GLOB
)
The grouping form!(``...``)
. -
’@(’
(KSH_GLOB
)
The grouping form@(``...``)
.
disown
[ job
... ]
job
... &|
job
... &!
no longer report their status, and will not complain if you try to exit
an interactive shell with them running or stopped. If no job
is
specified, disown the current job.
If the job
s are currently stopped and the AUTO_CONTINUE
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 job
s will automatically be made running,
independent of the setting of the AUTO_CONTINUE
option.
echo
[ -neE
] [ arg
... ]
Write each arg
on the standard output, with a space separating each
one. If the -n
flag is not present, print a newline at the end. echo
recognizes the following escape sequences:
-
\a
bell character -
\b
backspace -
\c
suppress subsequent characters and final newline -
\e
escape -
\f
form feed -
\n
linefeed (newline) -
\r
carriage return -
\t
horizontal tab -
\v
vertical tab -
\\
backslash -
\0``NNN
character code in octal -
\x``NN
character code in hexadecimal -
\u``NNNN
unicode character code in hexadecimal -
\U``NNNNNNNN
unicode character code in hexadecimal
The -E
flag, or the BSD_ECHO
option, can be used to disable these
escape sequences. In the latter case, -e
flag can be used to enable
them.
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 printf
,
and for a more controllable way of printing text within zsh, see
print
.
echotc
echoti
emulate
[ -lLR
] [ {zsh
|sh
|ksh
|csh
} [ flags
... ] ]
Without any argument print current emulation mode.
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, zsh
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 Compatibility . In addition
to setting shell options, the command also restores the pristine state
of pattern enables, as if all patterns had been enabled using enable -p
.
If the emulate
command occurs inside a function that has been marked
for execution tracing with functions -t
then the xtrace
option will
be turned on regardless of emulation mode or other options. Note that
code executed inside the function by the .
, source
, or eval
commands is not considered to be running directly from the function,
hence does not provoke this behaviour.
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 -L
switch is
given, the options LOCAL_OPTIONS
, LOCAL_PATTERNS
and LOCAL_TRAPS
will be set as well, causing the effects of the emulate
command and
any setopt
, disable -p
or enable -p
, and trap
commands to be
local to the immediately surrounding shell function, if any; normally
these options are turned off in all emulation modes except ksh
. The
-L
switch is mutually exclusive with the use of -c
in flags
.
If there is a single argument and the -l
switch is given, the options
that would be set or unset (the latter indicated with the prefix ‘no
’)
are listed. -l
can be combined with -L
or -R
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.
The flags
may be any of the invocation-time flags described in
Invocation, except that ‘-o EMACS
’ and
‘-o VI
’ may not be used. Flags such as ‘+r
’/‘+o RESTRICTED
’ may
be prohibited in some circumstances.
If -c
arg
appears in flags
, arg
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 emulate
returns. The -R
switch may precede the name of the shell to emulate;
note this has a meaning distinct from including -R
in flags
.
Use of -c
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 -R
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 ‘emulate
shell
-c
’ 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 LOCAL_OPTIONS
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.
For example:
emulate sh -c 'fni() { setopt cshnullglob; }
fno() { fni; }'
fno
The two functions fni
and fno
are defined with sticky sh
emulation. fno
is then executed, causing options associated with
emulations to be set to their values in sh
. fno
then calls fni
;
because fni
is also marked for sticky sh
emulation, no option
changes take place on entry to or exit from it. Hence the option
cshnullglob
, turned off by sh
emulation, will be turned on within
fni
and remain on return to fno
. On exit from fno
, the emulation
mode and all options will be restored to the state they were in before
entry to the temporary emulation.
The documentation above is typically sufficient for the intended environment. More detailed rules follow.
-
1.
The sticky emulation environment provided by ‘emulate
shell
-c
’ 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. -
2.
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. -
3.
No special handling is provided for functions marked forautoload
nor for functions present in wordcode created by thezcompile
command. -
4.
The presence or absence of the-R
switch toemulate
corresponds to different sticky emulation modes, so for example ‘emulate sh -c
’, ‘emulate -R sh -c
’ and ‘emulate csh -c
’ are treated as three distinct sticky emulations. -
5.
Difference in shell options supplied in addition to the basic emulation also mean the sticky emulations are different, so for example ‘emulate zsh -c
’ and ‘emulate zsh -o cbases -c
’ are treated as distinct sticky emulations.
enable
[ -afmprs
] name
...
earlier with disable
. The default is to enable builtin commands. The
-a
option causes enable
to act on regular or global aliases. The
-s
option causes enable
to act on suffix aliases. The -f
option
causes enable
to act on shell functions. The -r
option causes
enable
to act on reserved words. Without arguments printed. With the
-m
flag the arguments are taken as patterns disabled with the
disable
builtin command.
enable -p
reenables patterns disabled with disable -p
. Note that it
does not override globbing options; for example, ‘enable -p "~"
’ does
not cause the pattern character ~
to be active unless the
EXTENDED_GLOB
option is also set. To enable all possible patterns (so
that they may be individually disabled with disable -p
), use ‘setopt EXTENDED_GLOB KSH_GLOB NO_SH_GLOB
’.
eval
[ arg
... ]
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 args
or they contain no commands (i.e. are an empty string or
whitespace) the return status is zero.
exec
[ -cl
] [ -a
argv0
] [ command
[ arg
... ] ]
Replace the current shell with command
rather than forking. If
command
is a shell builtin command or a shell function, the shell
executes it, and exits when the command is complete.
With -c
clear the environment; with -l
prepend -
to the argv[0]
string of the command executed (to simulate a login shell); with -a
argv0
set the argv[0]
string of the command executed. See
Precommand Modifiers.
If the option POSIX_BUILTINS
is set, command
is never interpreted as
a shell builtin command or shell function. This means further precommand
modifiers such as builtin
and noglob
are also not interpreted within
the shell. Hence command
is always found by searching the command
path.
If command
is omitted but any redirections are specified, then the
redirections will take effect in the current shell.
exit
[ n
]
Exit the shell with the exit status specified by an arithmetic
expression n
; if none is specified, use the exit status from the last
command executed. An
EOF condition will also cause the shell to exit, unless the IGNORE_EOF
option is set.
See notes at the end of Jobs &
Signals for some possibly
unexpected interactions of the exit
command with jobs.
export
[ name
[=``value
] ... ]
The specified name
s are marked for automatic export to the environment
of subsequently executed commands. Equivalent to typeset -gx
. If a
parameter specified does not already exist, it is created in the global
scope.
false
[ arg
... ]
Do nothing and return an exit status of 1.
fc
[ -e
ename
] [ -LI
] [ -m
match
] [ old``=``new
... ] [ first
[ last
] ]
fc -l
[ -LI
] [ -nrdfEiD
] [ -t
timefmt
] [ -m
match
]
[ old``=``new
... ] [ first
[ last
] ]
fc -p
[ -a
] [ filename
[ histsize
[ savehistsize
] ]
]
fc
-P
fc
-ARWI
[ filename
]
The fc
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 interactive
option when starting the shell.
The first two forms of this command select a range of events from
first
to last
from the history list. The arguments first
and
last
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 old``=``new
, if any, are then performed on the text of
the events.
In addition to the number range,
-
-I
restricts to only internal events (not from$HISTFILE
) -
-L
restricts to only local events (not from other shells, seeSHARE_HISTORY
in Description of Options – note that$HISTFILE
is considered local when read at startup) -
-m
takes the first argument as a pattern (should be quoted) and only the history events matching this pattern are considered
If first
is not specified, it will be set to -1 (the most recent
event), or to -16 if the -l
flag is given. If last
is not specified,
it will be set to first
, or to -1 if the -l
flag is given. However,
if the current event has added entries to the history with ‘print -s
’
or ‘fc -R
’, then the default last
for -l
includes all new history
entries since the current event began.
When the -l
flag is given, the resulting events are listed on standard
output. Otherwise the editor program specified by -e
ename
is
invoked on a file containing these history events. If -e
is not given,
the value of the parameter FCEDIT
is used; if that is not set the
value of the parameter EDITOR
is used; if that is not set a builtin
default, usually ‘vi
’ is used. If ename
is ‘-
’, no editor is
invoked. When editing is complete, the edited command is executed.
The flag -r
reverses the order of the events and the flag -n
suppresses event numbers when listing.
Also when listing,
-
-d
prints timestamps for each event -
-f
prints full time-date stamps in the US ‘MM``/``DD``/``YY
hh``:``mm
’ format -
-E
prints full time-date stamps in the European ‘dd``.``mm``.``yyyy
hh``:``mm
’ format -
-i
prints full time-date stamps in ISO8601 ‘yyyy``-``mm``-``dd
hh``:``mm
’ format -
-t
fmt
prints time and date stamps in the given format;fmt
is formatted with the strftime function with the zsh extensions described for the%D{``string``}
prompt format in Prompt Expansion. The resulting formatted string must be no more than 256 characters or will not be printed -
-D
prints elapsed times; may be combined with one of the options above
‘fc -p
’ pushes the current history list onto a stack and switches to a
new history list. If the -a
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 ‘fc -P
’ manually. If no arguments are specified, the history list
is left empty, $HISTFILE
is unset, and $HISTSIZE
& $SAVEHIST
are
set to their default values. If one argument is given, $HISTFILE
is
set to that filename, $HISTSIZE
& $SAVEHIST
are left unchanged, and
the history file is read in (if it exists) to initialize the new list.
If a second argument is specified, $HISTSIZE
& $SAVEHIST
are instead
set to the single specified numeric value. Finally, if a third argument
is specified, $SAVEHIST
is set to a separate value from $HISTSIZE
.
You are free to change these environment values for the new history list
however you desire in order to manipulate the new history list.
‘fc -P
’ pops the history list back to an older list saved by ‘fc -p
’. The current list is saved to its $HISTFILE
before it is
destroyed (assuming that $HISTFILE
and $SAVEHIST
are set
appropriately, of course). The values of $HISTFILE
, $HISTSIZE
, and
$SAVEHIST
are restored to the values they had when ‘fc -p
’ was
called. Note that this restoration can conflict with making these
variables "local", so your best bet is to avoid local declarations for
these variables in functions that use ‘fc -p
’. The one other
guaranteed-safe combination is declaring these variables to be local at
the top of your function and using the automatic option (-a
) with ‘fc -p
’. 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.
‘fc -R
’ reads the history from the given file, ‘fc -W
’ writes the
history out to the given file, and ‘fc -A
’ appends the history out to
the given file. If no filename is specified, the $HISTFILE
is assumed.
If the -I
option is added to -R
, only those events that are not
already contained within the internal history list are added. If the
-I
option is added to -A
or -W
, 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
$SAVEHIST
entries.
fg
[ job
... ]
job
...
Bring each specified job
in turn to the foreground. If no job
is
specified, resume the current job.
float
[ {+
|-
}Hghlprtux
] [ {+
|-
}EFLRZ
[ n
] ] [
name
[=``value
] ... ]
Equivalent to typeset -E
, except that options irrelevant to floating
point numbers are not permitted.
functions
[ {+
|-
}UkmtTuWz
] [ -x
num
] [ name
... ]
functions -c
oldfn
newfn
functions -M
[-s
] mathfn
[ min
[ max
[ shellfn
] ] ]
functions -M
[ -m
pattern
... ]
functions +M
[ -m
] mathfn
...
Equivalent to typeset -f
, with the exception of the -c
, -x
, -M
and -W
options. For functions -u
and functions -U
, see autoload
,
which provides additional options.
The -x
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 num
of spaces. num
can also
be 0 to suppress all indentation.
The -W
option turns on the option WARN_NESTED_VAR
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 -W
attribute.
The -c
option causes oldfn
to be copied to newfn
. The copy is
efficiently handled internally by reference counting. If oldfn
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 oldfn
is the name of a library shell
function which is then redefined to call newfn
, thereby installing a
modified version of the function.
Use of the -M
option may not be combined with any of the options
handled by typeset -f
.
functions -M
mathfn
defines mathfn
as the name of a mathematical
function recognised in all forms of arithmetical expressions; see
Arithmetic
Evaluation. By
default mathfn
may take any number of comma-separated arguments. If
min
is given, it must have exactly min
args; if min
and max
are
both given, it must have at least min
and at most max
args. max
may be -1 to indicate that there is no upper limit.
By default the function is implemented by a shell function of the same
name; if shellfn
is specified it gives the name of the corresponding
shell function while mathfn
remains the name used in arithmetical
expressions. The name of the function in $0
is mathfn
(not shellfn
as would usually be the case), provided the option FUNCTION_ARGZERO
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.
If the additional option -s
is given to functions -M
, 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.
functions -M
with no arguments lists all such user-defined functions
in the same form as a definition. With the additional option -m
and a
list of arguments, all functions whose mathfn
matches one of the
pattern arguments are listed.
function +M
removes the list of mathematical functions; with the
additional option -m
the arguments are treated as patterns and all
functions whose mathfn
matches the pattern are removed. Note that the
shell function implementing the behaviour is not removed (regardless of
whether its name coincides with mathfn
).
For example, the following prints the cube of 3:
zmath_cube() { (( $1 * $1 * $1 )) }
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))
The following string function takes a single argument, including the commas, so prints 11:
stringfn() { (( $#1 )) }
functions -Ms stringfn
print $(( stringfn(foo,bar,rod) ))
getcap
See The zsh/cap Module.
getln
[ -AclneE
] name
...
Read the top value from the buffer stack and put it in the shell
parameter name
. Equivalent to read -zr
.
getopts
optstring
name
[ arg
... ]
Checks the arg
s for legal options. If the arg
s are omitted, use the
positional parameters. A valid option argument begins with a ‘+
’ or a
‘-
’. An argument not beginning with a ‘+
’ or a ‘-
’, or the
argument ‘-``-
’, ends the options. Note that a single ‘-
’ is not
considered a valid option argument. optstring
contains the letters
that getopts
recognizes. If a letter is followed by a ‘:
’, that
option requires an argument. The options can be separated from the
argument by blanks.
Each time it is invoked, getopts
places the option letter it finds in
the shell parameter name
, prepended with a ‘+
’ when arg
begins
with a ‘+
’. The index of the next arg
is stored in OPTIND
. The
option argument, if any, is stored in OPTARG
.
The first option to be examined may be changed by explicitly assigning
to OPTIND
. OPTIND
has an initial value of 1
, and is normally set
to 1
upon entry to a shell function and restored upon exit (this is
disabled by the POSIX_BUILTINS
option). OPTARG
is not reset and
retains its value from the most recent call to getopts
. If either of
OPTIND
or OPTARG
is explicitly unset, it remains unset, and the
index or option argument is not stored. The option itself is still
stored in name
in this case.
A leading ‘:
’ in optstring
causes getopts
to store the letter of
any invalid option in OPTARG
, and to set name
to ‘?
’ for an
unknown option and to ‘:
’ when a required argument is missing.
Otherwise, getopts
sets name
to ‘?
’ and prints an error message
when an option is invalid. The exit status is nonzero when there are no
more options.
hash
[ -Ldfmrv
] [ name
[=``value
] ] ...
hash
can be used to directly modify the contents of the command
A command name
starting with a /
is never hashed, whether by
explicit use of the hash
command or otherwise. Such a command is
always found by direct look up in the file system.
Given no arguments, and neither the -r
or -f
options,
It will be subsequently rebuilt in the normal fashion. all the absolute
directories in the PATH
, These two options cannot be used with any
arguments.
The -m
option causes the arguments to be taken as patterns matching
those patterns are printed. This is the only way to display
For each name
with a corresponding value
, put ‘name
’ in whenever
‘name
’ is used as a command argument, the shell will try to execute
the file given by ‘value
’. that ‘value
’ may be referred to as
‘~``name
’.
For each name
with no checking what the appropriate value
is in the
normal manner for
added by explicit specification. If has no effect if used with -f
.
the form of a call to hash.
history
Same as fc -l
.
integer
[ {+
|-
}Hghlprtux
] [ {+
|-
}LRZi
[ n
] ] [
name
[=``value
] ... ]
Equivalent to typeset -i
, except that options irrelevant to integers
are not permitted.
jobs
[ -dlprs
] [ job
... ]
jobs -Z
string
Lists information about each given job, or all jobs if job
is omitted.
The -l
flag lists process IDs, and the -p
flag lists process groups.
If the -r
flag is specified only running jobs will be listed and if
the -s
flag is given only stopped jobs are shown. If the -d
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.
The -Z
option replaces the shell’s argument and environment space with
the given string, truncated if necessary to fit. This will normally be
visible in ps
(man page ps(1)) listings. This feature is typically
used by daemons, to indicate their state.
kill
[ -s
signal_name
| -n
signal_number
| -``sig
] job
...
kill
-l
[ sig
... ]
Sends either SIGTERM
or the specified signal to the given jobs or
processes. Signals are given by number or by names, with or without the
‘SIG
’ prefix. If the signal being sent is not ‘KILL
’ or ‘CONT
’,
then the job will be sent a ‘CONT
’ signal if it is stopped. The
argument job
can be the process ID of a job not in the job list. In
the second form, kill -l
, if sig
is not specified the signal names
are listed. Otherwise, for each sig
that is a name, the corresponding
signal number is listed. For each sig
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.
On some systems, alternative signal names are allowed for a few signals.
Typical examples are SIGCHLD
and SIGCLD
or SIGPOLL
and SIGIO
,
assuming they correspond to the same signal number. kill -l
will only
list the preferred form, however kill -l
alt
will show if the
alternative form corresponds to a signal number. For example, under
Linux kill -l IO
and kill -l POLL
both output 29, hence kill -IO
and kill -POLL
have the same effect.
Many systems will allow process IDs to be negative to kill a process group or zero to kill the current process group.
let
arg
...
Evaluate each arg
as an arithmetic expression. See Arithmetic
Evaluation 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.
limit
[ -hs
] [ resource
[ limit
] ] ...
Set or display resource limits. Unless the -s
flag is given, the limit
applies only the children of the shell. If -s
is given without other
arguments, the resource limits of the current shell is set to the
previously set resource limits of the children.
If limit
is not specified, print the current limit placed on
resource
, otherwise set the limit to the specified value. If the -h
flag is given, use hard limits instead of soft limits. If no resource
is given, print all limits.
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.
resource
can be one of:
-
addressspace
Maximum amount of address space used. -
aiomemorylocked
Maximum amount of memory locked in RAM for AIO operations. -
aiooperations
Maximum number of AIO operations. -
cachedthreads
Maximum number of cached threads. -
coredumpsize
Maximum size of a core dump. -
cputime
Maximum CPU seconds per process. -
datasize
Maximum data size (including stack) for each process. -
descriptors
Maximum value for a file descriptor. -
filesize
Largest single file allowed. -
kqueues
Maximum number of kqueues allocated. -
maxproc
Maximum number of processes. -
maxpthreads
Maximum number of threads per process. -
memorylocked
Maximum amount of memory locked in RAM. -
memoryuse
Maximum resident set size. -
msgqueue
Maximum number of bytes in POSIX message queues. -
posixlocks
Maximum number of POSIX locks per user. -
pseudoterminals
Maximum number of pseudo-terminals. -
resident
Maximum resident set size. -
sigpending
Maximum number of pending signals. -
sockbufsize
Maximum size of all socket buffers. -
stacksize
Maximum stack size for each process. -
swapsize
Maximum amount of swap used. -
vmemorysize
Maximum amount of virtual memory.
Which of these resource limits are available depends on the system.
resource
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.
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 -s
option is present.
limit
is a number, with an optional scaling factor, as follows:
-
n``h
hours -
n``k
kilobytes (default) -
n``m
megabytes or minutes -
n``g
gigabytes -
[
mm``:
]ss
minutes and seconds
The limit
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 ‘zmodload -F zsh/rlimits b:limit
’.
local
[ {+
|-
}AHUahlprtux
] [ {+
|-
}EFLRZi
[ n
] ]
[ name
[=``value
] ... ]
Same as typeset
, except that the options -g
, and -f
are not
permitted. In this case the -x
option does not force the use of -g
,
i.e. exported variables will be local to functions.
log
List all users currently logged in who are affected by the current
setting of the watch
parameter.
logout
[ n
]
Same as exit
, except that it only works in a login shell.
noglob
simple command
See Precommand Modifiers.
popd
[ -q
] [ {+
|-
}n
]
Remove an entry from the directory stack, and perform a cd
to the new
top directory. With no argument, the current top entry is removed. An
argument of the form ‘+``n
’ identifies a stack entry by counting from
the left of the list shown by the dirs
command, starting with zero. An
argument of the form -``n
counts from the right.
If the
PUSHD_MINUS
option is set, the meanings of ‘+
’ and ‘-
’ in this
context are swapped.
If the -q
(quiet) option is specified, the hook function chpwd
and
the functions in the array $chpwd_functions
are not called, and the
new directory stack is not printed. This is useful for calls to popd
that do not change the environment seen by an interactive user.
print
[ -abcDilmnNoOpPrsSz
] [ -u
n
] [ -f
format
]
[ -C
cols
]
[ -v
name
] [ -xX
tabstop
] [ -R
[ -en
]] [
arg
... ]
With the ‘-f
’ option the arguments are printed as described by
printf
. With no flags or with the flag ‘-
’, the arguments are
printed on the standard output as described by echo
, with the
following differences: the escape sequence ‘\M-``x
’ (or ‘\M``x
’)
metafies the character x
(sets the highest bit), ‘\C-``x
’ (or
‘\C``x
’) produces a control character (‘\C-@
’ and ‘\C-?
’ give
the characters NULL and delete), a character code in octal is
represented by ‘\``NNN
’ (instead of ‘\0``NNN
’), and ‘\E
’ is a
synonym for ‘\e
’. Finally, if not in an escape sequence, ‘\
’ escapes
the following character and is not printed.
-
-a
Print arguments with the column incrementing first. Only useful with the-c
and-C
options. -
-b
Recognize all the escape sequences defined for thebindkey
command, see Zle Builtins. -
-c
Print the arguments in columns. Unless-a
is also given, arguments are printed with the row incrementing first. -
-C
cols
Print the arguments incols
columns. Unless-a
is also given, arguments are printed with the row incrementing first. -
-D
Treat the arguments as paths, replacing directory prefixes with~
expressions corresponding to directory names, as appropriate. -
-i
If given together with-o
or-O
, sorting is performed case-independently. -
-l
Print the arguments separated by newlines instead of spaces. Note: if the list of arguments is empty,print -l
will still output one empty line. To print a possibly-empty list of arguments one per line, useprint -C1
, as in ‘print -rC1 – "$list[@]"
’. -
-m
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. -
-n
Do not add a newline to the output. -
-N
Print the arguments separated and terminated by nulls. Again,print -rNC1 – "$list[@]"
is a canonical way to print an arbitrary list as null-delimited records. -
-o
Print the arguments sorted in ascending order. -
-O
Print the arguments sorted in descending order. -
-p
Print the arguments to the input of the coprocess. -
-P
Perform prompt expansion (see Prompt Expansion). In combination with ‘-f
’, prompt escape sequences are parsed only within interpolated arguments, not within the format string. -
-r
Ignore the escape conventions ofecho
. -
-R
Emulate the BSDecho
command, which does not process escape sequences unless the-e
flag is given. The-n
flag suppresses the trailing newline. Only the-e
and-n
flags are recognized after-R
; all other arguments and options are printed. -
-s
Place the results in the history list instead of on the standard output. Each argument to theprint
command is treated as a single word in the history, regardless of its content. -
-S
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 theHIST_LEX_WORDS
option active. -
-u
n
Print the arguments to file descriptorn
. -
-v
name
Store the printed arguments as the value of the parametername
. -
-x
tab-stop
Expand leading tabs on each line of output in the printed string assuming a tab stop everytab-stop
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 ifprint
is using spaces to separate arguments (the column count is maintained across arguments but may be incorrect on output owing to previous unexpanded tabs).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
MULTIBYTE
is in effect. This option is ignored if other formatting options are in effect, namely column alignment orprintf
style, or if output is to a special location such as shell history or the command line editor. -
-X
tab-stop
This is similar to-x
, except that all tabs in the printed string are expanded. This is appropriate if tabs in the arguments are -
-z
Push the arguments onto the editing buffer stack, separated by spaces.
If any of ‘-m
’, ‘-o
’ or ‘-O
’ are used in combination with ‘-f
’
and there are no arguments (after the removal process in the case of
‘-m
’) then nothing is printed.
printf
[ -v
name
] format
[ arg
... ]
Print the arguments according to the format specification. Formatting
rules are the same as used in C. The same escape sequences as for echo
are recognised in the format. All C conversion specifications ending in
one of csdiouxXeEfgGn
are handled. In addition to this, ‘%b
’ can be
used instead of ‘%s
’ to cause escape sequences in the argument to be
recognised and ‘%q
’ 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 Arithmetic
Evaluation for a
description of arithmetic expressions. With ‘%n
’, the corresponding
argument is taken as an identifier which is created as an integer
parameter.
Normally, conversion specifications are applied to each argument in
order but they can explicitly specify the n
th argument is to be used
by replacing ‘%
’ by ‘%``n``$
’ and ‘*
’ by ‘*``n``$
’. 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.
If arguments remain unused after formatting, the format string is reused
until all arguments have been consumed. With the print
builtin, this
can be suppressed by using the -r
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.
The -v
option causes the output to be stored as the value of the
parameter name
, instead of printed. If name
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.
pushd
[ -qsLP
] [ arg
]
pushd
[ -qsLP
] old
new
pushd
[ -qsLP
] {+
|-
}n
Change the current directory, and push the old current directory onto
the directory stack. In the first form, change the current directory to
arg
. If arg
is not specified, change to the second directory on the
stack (that is, exchange the top two entries), or change to $HOME
if
the PUSHD_TO_HOME
option is set or if there is only one entry on the
stack. Otherwise, arg
is interpreted as it would be by cd
. The
meaning of old
and new
in the second form is also the same as for
cd
.
The third form of pushd
changes directory by rotating the directory
list. An argument of the form ‘+``n
’ identifies a stack entry by
counting from the left of the list shown by the dirs
command, starting
with zero. An argument of the form ‘-``n
’ counts from the right. If
the PUSHD_MINUS
option is set, the meanings of ‘+
’ and ‘-
’ in this
context are swapped.
If the -q
(quiet) option is specified, the hook function chpwd
and
the functions in the array $chpwd_functions
are not called, and the
new directory stack is not printed. This is useful for calls to pushd
that do not change the environment seen by an interactive user.
If the option -q
is not specified and the shell option PUSHD_SILENT
is not set, the directory stack will be printed after a pushd
is
performed.
The options -s
, -L
and -P
have the same meanings as for the cd
builtin.
pushln
[ arg
... ]
Equivalent to print -nz
.
pwd
[ -rLP
]
Print the absolute pathname of the current working directory. If the
-r
or the -P
flag is specified, or the CHASE_LINKS
option is set
and the -L
flag is not given, the printed path will not contain
symbolic links.
r
Same as fc -e -
.
read
[ -rszpqAclneE
] [ -t
[ num
] ] [ -k
[ num
]
] [ -d
delim
]
[ -u
n
] [ name
[?``prompt
] ] [ name
... ]
Read one line and break it into fields using the characters in $IFS
as
separators, except as noted below. The first field is assigned to the
first name
, the second field to the second name
, etc., with leftover
fields assigned to the last name
. If name
is omitted then REPLY
is
used for scalars and reply
for arrays.
-
-r
Raw mode: a ‘\
’ 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. -
-s
Don’t echo back characters if reading from the terminal. -
-q
Read only one character from the terminal and setname
to ‘y
’ if this character was ‘y
’ or ‘Y
’ and to ‘n
’ otherwise. With this flag set the return status is zero only if the character was ‘y
’ or ‘Y
’. This option may be used with a timeout (see-t
); if the read times out, or encounters end of file, status 2 is returned. Input is read from the terminal unless one of-u
or-p
is present. This option may also be used within zle widgets. -
-k
[num
]
Read only one (ornum
) characters. All are assigned to the firstname
, without word splitting. This flag is ignored when-q
is present. Input is read from the terminal unless one of-u
or-p
is present. This option may also be used within zle widgets.Note that despite the mnemonic ‘key’ this option does read full characters, which may consist of multiple bytes if the option
MULTIBYTE
is set. -
-z
Read one entry from the editor buffer stack and assign it to the firstname
, without word splitting. Text is pushed onto the stack with ‘print -z
’ or withpush-line
from the line editor (see Zsh Line Editor). This flag is ignored when the-k
or-q
flags are present. -
-e
-E
The input read is printed (echoed) to the standard output. If the-e
flag is used, no input is assigned to the parameters. -
-A
The firstname
is taken as the name of an array and all words are assigned to it. -
-c
-l
These flags are allowed only if called inside a function used for completion (specified with the-K
flag tocompctl
). If the-c
flag is given, the words of the current command are read. If the-l
flag is given, the whole line is assigned as a scalar. If both flags are present,-l
is used and-c
is ignored. -
-n
Together with-c
, the number of the word the cursor is on is read. With-l
, 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. -
-u
n
Input is read from file descriptorn
. -
-p
Input is read from the coprocess. -
-d
delim
Input is terminated by the first character ofdelim
instead of by newline. -
-t
[num
]
Test if input is available before attempting to read. Ifnum
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. Ifnum
is not present, it is taken to be zero, so thatread
returns immediately if no input is available. If no input is available, return status 1 and do not set any variables.This option is not available when reading from the editor buffer with
-z
, when called from within completion with-c
or-l
, with-q
which clears the input queue before reading, or within zle where other mechanisms should be used to test for input.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 ‘
read -t
’ will not read anything until an entire line has been typed. However, when reading from the terminal with-k
input is processed one key at a time; in this case, only availability of the first character is tested, so that e.g. ‘read -t -k 2
’ can still block on the second character. Use two instances of ‘read -t -k
’ if this is not what is wanted.
If the first argument contains a ‘?
’, the remainder of this word is
used as a prompt
on standard error when the shell is interactive.
The value (exit status) of read
is 1 when an end-of-file is
encountered, or when -c
or -l
is present and the command is not
called from a compctl
function, or as described for -q
. Otherwise
the value is 0.
The behavior of some combinations of the -k
, -p
, -q
, -u
and -z
flags is undefined. Presently -q
cancels all the others, -p
cancels
-u
, -k
cancels -z
, and otherwise -z
cancels both -p
and -u
.
The -c
or -l
flags cancel any and all of -kpquz
.
readonly
Same as typeset -r
. With the POSIX_BUILTINS
option set, same as
typeset -gr
.
rehash
Same as hash -r
.
return
[ n
]
Causes a shell function or ‘.
’ script to return to the invoking script
with the return status specified by an arithmetic expression n
. If n
is omitted, the return status is that of the last command executed.
If return
was executed from a trap in a TRAP``NAL
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 ‘return $((128+$1))
’ will return the same status as if the
signal had not been trapped.
sched
See The zsh/sched Module.
set
[ {+
|-
}options
| {+
|-
}o
[ option_name
] ] ...
[ {+
|-
}A
[ name
] ]
[ arg
... ]
Set the options for the shell and/or set the positional parameters, or
declare and set an array. If the -s
option is given, it causes the
specified arguments to be sorted before assigning them to the positional
parameters (or to the array name
if -A
is used). With +s
sort
arguments in descending order. For the meaning of the other flags, see
Options. Flags may be specified by name using
the -o
option. If no option name is supplied with -o
, the current
option states are printed: see the description of setopt
below for
more information on the format. With +o
they are printed in a form
that can be used as input to the shell.
If the -A
flag is specified, name
is set to an array containing the
given arg
s; if no name
is specified, all arrays are printed together
with their values.
If +A
is used and name
is an array, the given arguments will replace
the initial elements of that array; if no name
is specified, all
arrays are printed without their values.
The behaviour of arguments after -A
name
or +A
name
depends on
whether the option KSH_ARRAYS
is set. If it is not set, all arguments
following name
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
set -A array -x -- foo
sets array
to ‘-x -``- foo
’ if KSH_ARRAYS
is not set, but sets the
array to foo
and turns on the option ‘-x
’ if it is set.
If the -A
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 ‘-``-
’, and there are no further arguments, the
positional parameters will be unset.
If no arguments and no ‘-``-
’ are given, then the names and values of
all parameters are printed on the standard output. If the only argument
is ‘+
’, the names of all parameters are printed.
For historical reasons, ‘set -
’ is treated as ‘set +xv
’ and ‘set -
args
’ as ‘set +xv –
args
’ when in any other emulation mode than
zsh’s native mode.
setcap
See The zsh/cap Module.
setopt
[ {+
|-
}options
| {+
|-
}o
option_name
] [ -m
] [ name
... ]
Set the options for the shell. All options specified either with flags or by name are set.
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 zsh
, shown as <Z>
in Description of
Options). Options that are on by
default for the emulation are shown with the prefix no
only if they
are off, while other options are shown without the prefix no
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,
SHIN_STDIN
or INTERACTIVE
) will be shown in the list. The format is
further modified by the option KSH_OPTION_PRINT
, however the rationale
for choosing options with or without the no
prefix remains the same in
this case.
If the -m
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.
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 ‘set -o
’. This is because set
is regarded as a special builtin by the
POSIX standard, but setopt
is not.
shift
[ -p
] [ n
] [ name
... ]
The positional parameters ${``n
+1}
... are renamed to $1
...,
where n
is an arithmetic expression that defaults to 1. If any name
s
are given then the arrays with these names are shifted instead of the
positional parameters.
If the option -p
is given arguments are instead removed (popped) from
the end rather than the start of the array.
source
file
[ arg
... ]
Same as ‘.
’, except that the current directory is always searched and
is always searched first, before directories in $path
.
stat
See The zsh/stat Module.
suspend
[ -f
]
Suspend the execution of the shell (send it a SIGTSTP
) until it
receives a SIGCONT
. Unless the -f
option is given, this will refuse
to suspend a login shell.
test
[ arg
... ]
[
[ arg
... ] ]
Like the system version of test
. Added for compatibility; use
conditional expressions instead (see Conditional
Expressions). The
main differences between the conditional expression syntax and the
test
and [
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.
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 ‘[[
’ test syntax which does not have these ambiguities.
times
Print the accumulated user and system times for the shell and for processes run from the shell.
trap
[ arg
] [ sig
... ]
arg
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 sig
args.
Each sig
can be given as a number, or as the name of a signal either
with or without the string SIG
in front (e.g. 1, HUP, and SIGHUP are
all the same signal).
If arg
is ‘-
’, then the specified signals are reset to their
defaults, or, if no sig
args are present, all traps are reset.
If arg
is an empty string, then the specified signals are ignored by
the shell (and by the commands it invokes).
If arg
is omitted but one or more sig
args are provided (i.e. the
first argument is a valid signal number or name), the effect is the same
as if arg
had been specified as ‘-
’.
The trap
command with no arguments prints a list of commands
associated with each signal.
If sig
is ZERR
then arg
will be executed after each command with a
nonzero exit status. ERR
is an alias for ZERR
on systems that have
no SIGERR
signal (this is the usual case).
If sig
is DEBUG
then arg
will be executed before each command if
the option DEBUG_BEFORE_CMD
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 Simple Commands &
Pipelines. If
DEBUG_BEFORE_CMD
is set various additional features are available.
First, it is possible to skip the next command by setting the option
ERR_EXIT
; see the description of the ERR_EXIT
option in Description
of Options. Also, the shell
parameter ZSH_DEBUG_CMD
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.
If sig
is 0
or EXIT
and the trap
statement is executed inside
the body of a function, then the command arg
is executed after the
function completes. The value of $?
at the start of execution is the
exit status of the shell or the return status of the function exiting.
If sig
is 0
or EXIT
and the trap
statement is not executed
inside the body of a function, then the command arg
is executed when
the shell terminates; the trap runs before any zshexit
hook functions.
ZERR
, DEBUG
, and EXIT
traps are not executed inside other traps.
ZERR
and DEBUG
traps are kept within subshells, while other traps
are reset.
Note that traps defined with the trap
builtin are slightly different
from those defined as ‘TRAP``NAL
() { ... }’, 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,
trap 'print $LINENO' DEBUG
will print the line number of a command executed after it has run, while
TRAPDEBUG() { print $LINENO; }
will always print the number zero.
Alternative signal names are allowed as described under kill
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.
true
[ arg
... ]
Do nothing and return an exit status of 0.
ttyctl
[ -fu
]
The -f
option freezes the tty (i.e. terminal or terminal emulator),
and -u
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, stty
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.
Without options it reports whether the terminal is frozen or not.
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 STTY
for a
means of initialising the tty before running external commands.
type
[ -wfpamsS
] name
...
Equivalent to whence -v
.
typeset
[ {+
|-
}AHUaghlmrtux
] [ {+
|-
}EFLRZip
[ n
] ]
[ +
] [ name
[=``value
] ... ]
typeset ``-T
[ {+
|-
}Uglrux
] [ {+
|-
}LRZp
[ n
] ]
[ +
| SCALAR
[=``value
] array
[=(``value
...)
]
[ sep
] ]
typeset
-f
[ {+
|-
}TUkmtuz
] [ +
] [ name
... ]
Set or display attributes and values for shell parameters.
Except as noted below for control flags that change the behavior, a
parameter is created for each name
that does not already refer to one.
When inside a function, a new parameter is created for every name
(even those that already exist), and is unset again when the function
completes. See Local Parameters. The
same rules apply to special shell parameters, which retain their special
attributes when made local.
For each name``=``value
assignment, the parameter name
is set to
value
.
If the shell option TYPESET_SILENT
is not set, for each remaining
name
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 name
. Using ‘+
’ instead of
minus to introduce an attribute turns it off.
If no name
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 ‘+
’
rather than ‘-
’ to introduce the flag suppresses printing of the
values of parameters when there is no parameter name.
All forms of the command handle scalar assignment. Array assignment is
possible if any of the reserved words declare
, export
, float
,
integer
, local
, readonly
or typeset
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 ‘+=
’ syntax and the
GLOB_ASSIGN
option are not supported, and scalar values after =
are
not split further into words, even if expanded (regardless of the
setting of the KSH_TYPESET
option; this option is obsolete).
Examples of the differences between command and reserved word parsing:
# Reserved word parsing
typeset svar=$(echo one word) avar=(several words)
The above creates a scalar parameter svar
and an array parameter
avar
as if the assignments had been
svar="one word"
avar=(several words)
On the other hand:
# Normal builtin interface
builtin typeset svar=$(echo two words)
The builtin
keyword causes the above to use the standard builtin
interface to typeset
in which argument parsing is performed in the
same way as for other commands. This example creates a scalar svar
containing the value two
and another scalar parameter words
with no
value. An array value in this case would either cause an error or be
treated as an obscure set of glob qualifiers.
Arbitrary arguments are allowed if they take the form of assignments after command line expansion; however, these only perform scalar assignment:
var='svar=val'
typeset $var
The above sets the scalar parameter svar
to the value val
.
Parentheses around the value within var
would not cause array
assignment as they will be treated as ordinary characters when $var
is
substituted. Any non-trivial expansion in the name part of the
assignment causes the argument to be treated in this fashion:
typeset {var1,var2,var3}=name
The above syntax is valid, and has the expected effect of setting the
three parameters to the same value, but the command line is parsed as a
set of three normal command line arguments to typeset
after expansion.
Hence it is not possible to assign to multiple arrays by this means.
Note that each interface to any of the commands my be disabled
separately. For example, ‘disable -r typeset
’ disables the reserved
word interface to typeset
, exposing the builtin interface, while
‘disable typeset
’ disables the builtin. Note that disabling the
reserved word interface for typeset
may cause problems with the output
of ‘typeset -p
’, which assumes the reserved word interface is
available in order to restore array and associative array values.
Unlike parameter assignment statements, typeset
’s exit status on an
assignment that involves a command substitution does not reflect the
exit status of the command substitution. Therefore, to test for an error
in a command substitution, separate the declaration of the parameter
from its initialization:
# WRONG
typeset var1=$(exit 1) || echo "Trouble with var1"
# RIGHT
typeset var1 && var1=$(exit 1) || echo "Trouble with var1"
To initialize a parameter param
to a command output and mark it
readonly, use typeset -r ``param
or readonly ``param
after the
parameter assignment statement.
If no attribute flags are given, and either no name
arguments are
present or the flag +m
is used, then each parameter name printed is
preceded by a list of the attributes of that parameter (array
,
association
, exported
, float
, integer
, readonly
, or
undefined
for autoloaded parameters not yet loaded). If +m
is used
with attribute flags, and all those flags are introduced with +
, the
matching parameter names are printed but their values are not.
The following control flags change the behavior of typeset
:
-
+
If ‘+
’ appears by itself in a separate word as the last option, then the names of all parameters (functions with-f
) are printed, but the values (function bodies) are not. Noname
arguments may appear, and it is an error for any other options to follow ‘+
’. The effect of ‘+
’ is as if all attribute flags which precede it were given with a ‘+
’ prefix. For example, ‘typeset -U +
’ is equivalent to ‘typeset +U
’ and displays the names of all arrays having the uniqueness attribute, whereas ‘typeset -f -U +
’ displays the names of all autoloadable functions. If+
is the only option, then type information (array, readonly, etc.) is also printed for each parameter, in the same manner as ‘typeset +m "*"
’. -
-g
The-g
(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+g
have any effect except in combination with-m
(see below). -
-m
If the-m
flag is given thename
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-f
flag) with matching names are printed (the shell optionTYPESET_SILENT
is not used in this case).If the
+g
flag is combined with-m
, a new local parameter is created for every matching parameter that is not already local. Otherwise-m
applies all other flags or assignments to the existing parameters.Except when assignments are made with
name``=``value
, using+m
forces the matching parameters and their attributes to be printed, even inside a function. Note that-m
is ignored if no patterns are given, so ‘typeset -m
’ displays attributes but ‘typeset -a +m
’ does not. -
-p
[n
]
If the-p
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-H
flag on parameters is respected; no value will be shown for these parameters.-p
may be followed by an optional integer argument. Currently only the value1
is supported. In this case arrays and associative arrays are printed with newlines between indented elements for readability. -
-T
[scalar
[=``value
]array
[=(``value
...)
] [sep
] ]
This flag has a different meaning when used with-f
; see below. Otherwise the-T
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$PATH
and$path
. The optional third argument is a single-character separator which will be used to join the elements of the array to form the scalar; if absent, a colon is used, as with$PATH
. Only the first character of the separator is significant; any remaining characters are ignored. Multibyte characters are not yet supported.Only one of the scalar and array parameters may be assigned an initial value (the restrictions on assignment forms described above also apply).
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
typeset
command;+T
does not work, assigning an array toscalar
is an error, and assigning a scalar toarray
sets it to be a single-element array.Note that both ‘
typeset -xT ...
’ and ‘export -T ...
’ 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-T
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.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.
Attribute flags that transform the final value (-L
, -R
, -Z
, -l
,
-u
) are only applied to the expanded value at the point of a parameter
expansion expression using ‘$
’. They are not applied when a parameter
is retrieved internally by the shell for any purpose.
The following attribute flags may be specified:
-
-A
The names refer to associative array parameters; see Array Parameters. -
-L
[n
]
Left justify and remove leading blanks from the value when the parameter is expanded. Ifn
is nonzero, it defines the width of the field. Ifn
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.The width is the count of characters, which may be multibyte characters if the
MULTIBYTE
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${(ml``...``)``...``}
as described in ‘Parameter Expansion Flags’ in Parameter Expansion.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
-Z
flag is also set. -
-R
[n
]
Similar to-L
, 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-Z
flag. -
-U
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-T
) or colon-separated special parameters likePATH
orFIGNORE
, 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. ‘typeset -U PATH path
’.This flag has a different meaning when used with
-f
; see below. -
-Z
[n
]
Specially handled if set along with the-L
flag. Otherwise, similar to-R
, 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. -
-a
The names refer to array parameters. An array parameter may be created this way, but it may be assigned to in thetypeset
statement only if the reserved word form oftypeset
is enabled (as it is by default). When displaying, both normal and associative arrays are shown. -
-f
The names refer to functions rather than parameters. No assignments can be made, and the only other valid flags are-t
,-T
,-k
,-u
,-U
and-z
. The flag-t
turns on execution tracing for this function; the flag-T
does the same, but turns off tracing for any named (not anonymous) function called from the present one, unless that function also has the-t
or-T
flag. The-u
and-U
flags cause the function to be marked for autoloading;-U
also causes alias expansion to be suppressed when the function is loaded. See the description of the ‘autoload
’ builtin for details.Note that the builtin
functions
provides the same basic capabilities astypeset -f
but gives access to a few extra options;autoload
gives further additional options for the casetypeset -fu
andtypeset -fU
. -
-h
-H
Hide value: specifies thattypeset
will not display the value of the parameter when listing parameters; the display for such parameters is always as if the ‘+
’ 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-m
option. This is on by default for the parameters in thezsh/parameter
andzsh/mapfile
modules. Note, however, that unlike the-h
flag this is also useful for non-special parameters. -
-i
[n
]
Use an internal integer representation. Ifn
is nonzero it defines the output arithmetic base, otherwise it is determined by the first assignment. Bases from 2 to 36 inclusive are allowed. -
-E
[n
]
Use an internal double-precision floating point representation. On output the variable will be converted to scientific notation. Ifn
is nonzero it defines the number of significant figures to display; the default is ten. -
-F
[n
]
Use an internal double-precision floating point representation. On output the variable will be converted to fixed-point decimal notation. Ifn
is nonzero it defines the number of digits to display after the decimal point; the default is ten. -
-l
Convert the result to lower case whenever the parameter is expanded. The value is not converted when assigned. -
-r
The givenname
s are marked readonly. Note that ifname
is a special parameter, the readonly attribute can be turned on, but cannot then be turned off.If the
POSIX_BUILTINS
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.It is still possible to change other attributes of the variable though, some of which like
-U
or-Z
would affect the value. More generally, the readonly attribute should not be relied on as a security mechanism.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.
-
-t
Tags the named parameters. Tags have no special meaning to the shell. This flag has a different meaning when used with-f
; see above. -
-u
Convert the result to upper case whenever the parameter is expanded. The value is not converted when assigned. This flag has a different meaning when used with-f
; see above. -
-x
Mark for automatic export to the environment of subsequently executed commands. If the optionGLOBAL_EXPORT
is set, this implies the option-g
, unless+g
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.
ulimit
[ -HSa
] [ { -bcdfiklmnpqrsTtvwx
| -N
resource
} [
limit
] ... ]
Set or display resource limits of the shell and the processes started by
the shell. The value of limit
can be a number in the unit specified
below or one of the values ‘unlimited
’, which removes the limit on the
resource, or ‘hard
’, which uses the current value of the hard limit on
the resource.
By default, only soft limits are manipulated. If the -H
flag is given
use hard limits instead of soft limits. If the -S
flag is given
together with the -H
flag set both hard and soft limits.
If no options are used, the file size limit (-f
) is assumed.
If limit
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.
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.
Not all the following resources are supported on all systems. Running
ulimit -a
will show which are supported.
-
-a
Lists all of the current resource limits. -
-b
Socket buffer size in bytes (N.B. not kilobytes) -
-c
512-byte blocks on the size of core dumps. -
-d
Kilobytes on the size of the data segment. -
-f
512-byte blocks on the size of files written. -
-i
The number of pending signals. -
-k
The number of kqueues allocated. -
-l
Kilobytes on the size of locked-in memory. -
-m
Kilobytes on the size of physical memory. -
-n
open file descriptors. -
-p
The number of pseudo-terminals. -
-q
Bytes in POSIX message queues. -
-r
Maximum real time priority. On some systems where this is not available, such as NetBSD, this has the same effect as-T
for compatibility withsh
. -
-s
Kilobytes on the size of the stack. -
-T
The number of simultaneous threads available to the user. -
-t
CPU seconds to be used. -
-u
The number of processes available to the user. -
-v
Kilobytes on the size of virtual memory. On some systems this refers to the limit called ‘address space’. -
-w
Kilobytes on the size of swapped out memory. -
-x
The number of locks on files.
A resource may also be specified by integer in the form ‘-N
resource
’, where resource
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 ‘ulimit -a
’.
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.
umask
[ -S
] [ mask
]
The umask is set to mask
. mask
can be either an octal number or a
symbolic value as described in man page chmod(1). If mask
is omitted,
the current value is printed. The -S
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.
unalias
[ -ams
] name
...
Removes aliases. This command works the same as unhash -a
, except that
the -a
option removes all regular or global aliases, or with -s
all
suffix aliases: in this case no name
arguments may appear. The options
-m
(remove by pattern) and -s
without -a
(remove listed suffix
aliases) behave as for unhash -a
. Note that the meaning of -a
is
different between unalias
and unhash
.
unfunction
Same as unhash -f
.
unhash
[ -adfms
] name
...
option causes unhash
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 -s
option
causes unhash
to remove suffix aliases. The -f
option causes
unhash
to remove shell functions. The -d
options causes unhash
to
remove named directories. If the -m
flag is given the arguments are
taken as patterns (should be quoted) and all elements
unlimit
[ -hs
] resource
...
The resource limit for each resource
is set to the hard limit. If the
-h
flag is given and the shell has appropriate privileges, the hard
resource limit for each resource
is removed. The resources of the
shell process are only changed if the -s
flag is given.
The unlimit
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 ‘zmodload -F zsh/rlimits b:unlimit
’.
unset
[ -fmv
] name
...
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.
Individual elements of associative array parameters may be unset by
using subscript syntax on name
, which should be quoted (or the entire
command prefixed with noglob
) to protect the subscript from filename
generation.
If the -m
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.
The -v
flag specifies that name
refers to parameters. This is the
default behaviour.
unset -f
is equivalent to unfunction
.
unsetopt
[ {+
|-
}options
| {+
|-
}o
option_name
] [
name
... ]
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 -m
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.
vared
See Zle Builtins.
wait
[ job
... ]
Wait for the specified jobs or processes. If job
is not given then all
currently active child processes are waited for. Each job
can be
either a job specification or the process ID The exit status from this
command is that of the job waited for. If job
represents an unknown
job or process ID, a warning is printed (unless the POSIX_BUILTINS
option is set) and the exit status is 127.
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 $!
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
CHILD_MAX
. When this limit is reached, older process IDs are
discarded, least recently started processes first.
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.
whence
[ -vcwfpamsS
] [ -x
num
] name
...
For each name
, indicate how it would be interpreted if used as a
command name.
If name
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 -v
, -c
, or -w
was passed — a message will be
written to standard output. (This is different from other shells that
write that message to standard error.)
whence
is most useful when name
is only the last path component of a
command, i.e. does not include a ‘/
’; in particular, pattern matching
only succeeds if just the non-directory component of the command is
passed.
-
-v
Produce a more verbose report. -
-c
Print the results in a csh-like format. This takes precedence over-v
. -
-w
For eachname
, print ‘name``:
word
’ whereword
is one ofalias
,builtin
,command
,function
,hashed
,reserved
ornone
, according asname
corresponds to an alias, a built-in command, an external command, a shell function, a command defined with thehash
builtin, a reserved word, or is not recognised. This takes precedence over-v
and-c
. -
-f
Causes the contents of a shell function to be displayed, which would otherwise not happen unless the-c
flag were used. -
-p
Do a path search forname
even if it is an alias, reserved word, shell function or builtin. -
-a
Do a search for all occurrences ofname
throughout the command path. Normally only the first occurrence is printed. -
-m
The arguments are taken as patterns (pattern characters should be quoted), and the information is displayed for each command matching one of these patterns. -
-s
If a pathname contains symlinks, print the symlink-free pathname as well. -
-S
As-s
, 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. -
-x
num
Expand tabs when outputting shell functions using the-c
option. This has the same effect as the-x
option to thefunctions
builtin.
where
[ -wpmsS
] [ -x
num
] name
...
Equivalent to whence -ca
.
which
[ -wpamsS
] [ -x
num
] name
...
Equivalent to whence -c
.
zcompile
[ -U
] [ -z
| -k
] [ -R
| -M
] file
[
name
... ]
zcompile
-ca
[ -m
] [ -R
| -M
] file
[ name
... ]
zcompile -t
file
[ name
... ]
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.
The first form (without the -c
, -a
or -t
options) creates a
compiled file. If only the file
argument is given, the output file has
the name ‘file``.zwc
’ and will be placed in the same directory as the
file
. The shell will load the compiled file instead of the normal
function file when the function is autoloaded; see
Functions for a description of how
autoloaded functions are searched. The extension .zwc
stands for ‘zsh
word code’.
If there is at least one name
argument, all the named files are
compiled into the output file
given as the first argument. If file
does not end in .zwc
, this extension is automatically appended. Files
containing multiple compiled functions are called ‘digest’ files, and
are intended to be used as elements of the FPATH
/fpath
special
array.
The second form, with the -c
or -a
options, writes the compiled
definitions for all the named functions into file
. For -c
, 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 -a
option, in which case the fpath
is searched
and the contents of the definition files for those functions, if found,
are compiled into file
. If both -c
and -a
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 -c
or -a
option
will be autoloaded as if the KSH_AUTOLOAD
option were unset.
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
‘zcompile -c
’ does not include the additional functions defined in
the file, and any other initialization code in the file is lost. Using
‘zcompile -a
’ captures all this extra information.
If the -m
option is combined with -c
or -a
, the name
s are used
as patterns and all functions whose names match one of these patterns
will be written. If no name
is given, the definitions of all functions
currently defined or marked as autoloaded will be written.
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
fn1() { { ... } >~/logfile }
can be compiled but
fn1() { ... } >~/logfile
cannot. It is possible to use the first form of zcompile
to compile
autoloadable functions that include the full function definition instead
of just the body of the function.
The third form, with the -t
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 all name
s were found in the compiled file, and non-zero if the
definition for at least one name
was not found.
Other options:
-
-U
Aliases are not expanded when compiling thename
d files. -
-R
When the compiled file is read, its contents are copied into the shell’s memory, rather than memory-mapped (see-M
). This happens automatically on systems that do not support memory mapping.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.
-
-M
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-R
nor-M
is given, thezcompile
builtin decides what to do based on the size of the compiled file. -
-k
-z
These options are used when the compiled file contains functions which are to be autoloaded. If-z
is given, the function will be autoloaded as if theKSH_AUTOLOAD
option is not set, even if it is set at the time the compiled file is read, while if the-k
is given, the function will be loaded as ifKSH_AUTOLOAD
is set. These options also take precedence over any-k
or-z
options specified to theautoload
builtin. If neither of these options is given, the function will be loaded as determined by the setting of theKSH_AUTOLOAD
option at the time the compiled file is read.These options may also appear as many times as necessary between the listed
name
s to specify the loading style of all following functions, up to the next-k
or-z
.
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).
zformat
See The zsh/zutil Module.
zftp
See The zsh/zftp Module.
zle
See Zle Builtins.
zmodload
[ -dL
] [ -s
] [ ... ]
zmodload -F
[ -alLme
-P
param
] module
[ [+-
]feature
... ]
zmodload -e
[ -A
] [ ... ]
zmodload
[ -a
[ -bcpf
[ -I
] ] ] [ -iL
] ...
zmodload
-u
[ -abcdpf
[ -I
] ] [ -iL
] ...
zmodload
-A
[ -L
] [ modalias
[=``module
] ... ]
zmodload
-R
modalias
...
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 zmodload
command itself is
always available and can be used to manipulate modules built into
versions of the
Without arguments the names of all currently loaded binary modules are
printed. The -L
option causes this list to be in the form of a series
of zmodload
commands. Forms with arguments are:
-
zmodload
[-is
]name
...
zmodload
-u
[-i
]name
...
In the simplest case,zmodload
loads a binary module. The module must be in a file with a name consisting of the specifiedname
followed by a standard suffix, usually ‘.so
’ (‘.sl
’ on HPUX). If the module to be loaded is already loaded the duplicate module is ignored. Ifzmodload
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-i
is accepted for compatibility but has no effect.The
name
d module is searched for in the same way a command is, using$module_path
instead of$path
. However, the path search is performed even when the module name contains a ‘/
’, which it usually does. There is no way to prevent the path search.If the module supports features (see below),
zmodload
tries to enable all features when loading a module. If the module was successfully loaded but not all features could be enabled,zmodload
returns status 2.If the option
-s
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.With
-u
,zmodload
unloads modules. The samename
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-i
option suppresses the error if the module is already unloaded (or was never loaded).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.
-
zmodload -F
[-almLe
-P
param
]module
[ [+-
]feature
... ]
zmodload -F
allows more selective control over the features provided by modules. With no options apart from-F
, the module namedmodule
is loaded, if it was not already loaded, and the list offeature
s is set to the required state. If nofeature
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+
to turn the feature on, or-
to turn it off; the+
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.The standard features are builtins, conditions, parameters and math functions; these are indicated by the prefix ‘
b:
’, ‘c:
’ (‘C:
’ for an infix condition), ‘p:
’ and ‘f:
’, respectively, followed by the name that the corresponding feature would have in the shell. For example, ‘b:strftime
’ indicates a builtin namedstrftime
andp:EPOCHSECONDS
indicates a parameter namedEPOCHSECONDS
. The module may provide other (‘abstract’) features of its own as indicated by its documentation; these have no prefix.With
-l
or-L
, features provided by the module are listed. With-l
alone, a list of features together with their states is shown, one feature per line. With-L
alone, azmodload -F
command that would cause enabled features of the module to be turned on is shown. With-lL
, azmodload -F
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-P
param
then the parameterparam
is set to an array of features, either features together with their state or (if-L
alone is given) enabled features.With the option
-L
the module name may be omitted; then a list of all enabled features for all modules providing features is printed in the form ofzmodload -F
commands. If-l
is also given, the state of both enabled and disabled features is output in that form.A set of features may be provided together with
-l
or-L
and a module name; in that case only the state of those features is considered. Each feature may be preceded by+
or-
but the character has no effect. If no set of features is provided, all features are considered.With
-e
, 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+
or-
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.With
-m
, 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+
or-
must be given explicitly. This may not be combined with the-a
option as autoloads must be specified explicitly.With
-a
, the given list of features is marked for autoload from the specified module, which may not yet be loaded. An optional+
may appear before the feature name. If the feature is prefixed with-
, any existing autoload is removed. The options-l
and-L
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 ‘zmodload -Fa
module
-``feature
’ is issued. It is not an error to request an autoload for a feature of a module that is already loaded.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
zmodload -Fa
is run, an error message is printed and status 1 returned.zmodload -Fa
can be used with the-l
,-L
,-e
and-P
options for listing and testing the existence of autoloadable features. In this case-l
is ignored if-L
is specified.zmodload -FaL
with no module name lists autoloads for all modules.Note that only standard features as described above can be autoloaded; other features require the module to be loaded before enabling.
-
zmodload
-d
[-L
] [name
]
zmodload
-d
name
dep
...
zmodload
-ud
name
[dep
... ]
The-d
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.With
-d
and one argument, all dependencies for that module are listed. With-d
and no arguments, all module dependencies are listed. This listing is by default in a Makefile-like format. The-L
option changes this format to a list ofzmodload -d
commands.If
-d
and-u
are both used, dependencies are removed. If only one argument is given, all dependencies for that module are removed. -
zmodload
-ab
[-L
]
zmodload
-ab
[-i
]name
[builtin
... ]
zmodload
-ub
[-i
]builtin
...
The-ab
option defines autoloaded builtins. It defines the specifiedbuiltin
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 ‘zmodload -F -a
’ as described above). If only thename
is given, one builtin is defined, with the same name as the module.-i
suppresses the error if the builtin is already defined or autoloaded, but not if another builtin of the same name is already defined.With
-ab
and no arguments, all autoloaded builtins are listed, with the module name (if different) shown in parentheses after the builtin name. The-L
option changes this format to a list ofzmodload -a
commands.If
-b
is used together with the-u
option, it removes builtins previously defined with-ab
. This is only possible if the builtin is not yet loaded.-i
suppresses the error if the builtin is already removed (or never existed).Autoload requests are retained if the module is subsequently unloaded until an explicit ‘
zmodload -ub
builtin
’ is issued. -
zmodload
-ac
[-IL
]
zmodload
-ac
[-iI
]name
[cond
... ]
zmodload
-uc
[-iI
]cond
...
The-ac
option is used to define autoloaded condition codes. Thecond
strings give the names of the conditions defined by the module. The optional-I
option is used to define infix condition names. Without this option prefix condition names are defined.If given no condition names, all defined names are listed (as a series of
zmodload
commands if the-L
option is given).The
-uc
option removes definitions for autoloaded conditions. -
zmodload
-ap
[-L
]
zmodload
-ap
[-i
]name
[parameter
... ]
zmodload
-up
[-i
]parameter
...
The-p
option is like the-b
and-c
options, but makeszmodload
work on autoloaded parameters instead. -
zmodload
-af
[-L
]
zmodload
-af
[-i
]name
[function
... ]
zmodload
-uf
[-i
]function
...
The-f
option is like the-b
,-p
, and-c
options, but makeszmodload
work on autoloaded math functions instead. -
zmodload
-a
[-L
]
zmodload
-a
[-i
]name
[builtin
... ]
zmodload
-ua
[-i
]builtin
...
Equivalent to-ab
and-ub
. -
zmodload -e
[-A
] [string
... ]
The-e
option without arguments lists all loaded modules; if the-A
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 allstring
s given as arguments are names of loaded modules and to one if at least onstring
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-A
flag is not used. -
zmodload
-A
[-L
] [modalias
[=``module
] ... ]
For each argument, if bothmodalias
andmodule
are given, definemodalias
to be an alias for the modulemodule
. If the modulemodalias
is ever subsequently requested, either via a call tozmodload
or implicitly, the shell will attempt to loadmodule
instead. Ifmodule
is not given, show the definition ofmodalias
. If no arguments are given, list all defined module aliases. When listing, if the-L
flag was also given, list the definition as azmodload
command to recreate the alias.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
zmodload -R
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, ‘any/old/alias
’ is always a valid alias.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.
Apart from the above, aliases can be used in the
zmodload
command anywhere module names are required. However, aliases will not be shown in lists of loaded modules with a bare ‘zmodload
’. -
zmodload
-R
modalias
...
For eachmodalias
argument that was previously defined as a module alias viazmodload -A
, delete the alias. If any was not defined, an error is caused and the remainder of the line is ignored.
Note that zsh
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.
zparseopts
See The zsh/zutil Module.
zprof
See The zsh/zprof Module.
zpty
See The zsh/zpty Module.
zregexparse
See The zsh/zutil Module.
zsocket
See The zsh/net/socket Module.
zstyle
See The zsh/zutil Module.
ztcp
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 18 Zsh Line Editor
18 Zsh Line Editor
18.1 Description
If the ZLE
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.
There are two display modes. The first, multiline mode, is the default.
It only works if the TERM
parameter is set to a valid terminal type
that can move the cursor up. The second, single line mode, is used if
TERM
is invalid or incapable of moving the cursor up, or if the
SINGLE_LINE_ZLE
option is set.
This mode is similar to ksh,
and uses no termcap sequences. If TERM
is "emacs", the ZLE
option
will be unset by default.
The parameters BAUD
, COLUMNS
, and LINES
are also used by the line
editor. See Parameters Used By The
Shell.
The parameter zle_highlight
is also used by the line editor; see
Character Highlighting. Highlighting of
special characters and the region between the cursor and the mark (as
set with set-mark-command
in Emacs mode, or by visual-mode
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:
zle_highlight=(none)
In many places, references are made to the numeric argument
. 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 digit-argument
widget. See also Arguments for some
other ways the numeric argument can be modified.
18.2 Keymaps
A keymap in ZLE contains a set of bindings between key sequences and ZLE commands. The empty key sequence cannot be bound.
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.
bindkey
can be used to
manipulate keymap names.
Initially, there are eight keymaps:
-
emacs
EMACS emulation -
viins
vi emulation - insert mode -
vicmd
vi emulation - command mode -
viopp
vi emulation - operator pending -
visual
vi emulation - selection active -
isearch
incremental search mode -
command
read a command name -
.safe
fallback keymap
The ‘.safe
’ 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 ‘.
’ for their own keymaps.
In addition to these names, either ‘emacs
’ or ‘viins
’ is also linked
to the name ‘main
’. If one of the VISUAL
or EDITOR
environment
variables contain the string ‘vi
’ when the shell starts up then it
will be ‘viins
’, otherwise it will be ‘emacs
’. bindkey
’s -e
and
-v
options provide a convenient way to override this default choice.
When the editor starts up, it will select the ‘main
’ keymap. If that
keymap doesn’t exist, it will use ‘.safe
’ instead.
In the ‘.safe
’ keymap, each single key is bound to self-insert
,
except for ^J (line feed) and ^M (return) which are bound to
accept-line
. 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.
18.2.1 Reading Commands
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 KEYTIMEOUT
parameter; its default is 0.4 sec. There is no timeout if the prefix
string is not itself bound to a command.
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 ?
were typed and resets the input
state.
As well as ZLE commands, key sequences can be bound to other strings, by
using ‘bindkey -s
’. 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.
A key sequence typed by the user can be turned into a command name for
use in user-defined widgets with the read-command
widget, described in
Miscellaneous below.
18.2.2 Local Keymaps
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 isearch
keymap will
override a binding in the main
keymap but all keys that are not
overridden can still be used.
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 iw
in viopp
as this hides
the binding of i
in vicmd
. However, a longer sequence in the global
keymap that shares the same prefix can still apply so for example the
binding of ^Xa
in the global keymap will be unaffected by the binding
of ^Xb
in the local keymap.
18.3 Zle Builtins
The ZLE module contains three related builtin commands. The bindkey
command manipulates keymaps and key bindings; the vared
command
invokes ZLE on the value of a shell parameter; and the zle
command
manipulates editing widgets and allows command line access to ZLE
commands from within shell functions.
bindkey
[ options
] -l
[ -L
] [ keymap
... ]
bindkey
[ options
] -d
bindkey
[ options
] -D
keymap
...
bindkey
[ options
] -A
old-keymap new-keymap
bindkey
[ options
] -N
new-keymap
[ old-keymap
]
bindkey
[ options
] -m
bindkey
[ options
] -r
in-string
...
bindkey
[ options
] -s
in-string out-string
...
bindkey
[ options
] in-string command
...
bindkey
[ options
] [ in-string
]
bindkey
’s options can be divided into three categories: keymap
selection for the current command, operation selection, and others. The
keymap selection options are:
-
-e
Selects keymap ‘emacs
’ for any operations by the current command, and also links ‘emacs
’ to ‘main
’ so that it is selected by default the next time the editor starts. -
-v
Selects keymap ‘viins
’ for any operations by the current command, and also links ‘viins
’ to ‘main
’ so that it is selected by default the next time the editor starts. -
-a
Selects keymap ‘vicmd
’ for any operations by the current command. -
-M
keymap
Thekeymap
specifies a keymap name that is selected for any operations by the current command.
If a keymap selection is required and none of the options above are
used, the ‘main
’ keymap is used. Some operations do not permit a
keymap to be selected, namely:
-
-l
List all existing keymap names; if any arguments are given, list just those keymaps.If the
-L
option is also used, list in the form ofbindkey
commands to create or link the keymaps. ‘bindkey -lL main
’ shows which keymap is linked to ‘main
’, if any, and hence if the standard emacs or vi emulation is in effect. This option does not show the.safe
keymap because it cannot be created in that fashion; however, neither is ‘bindkey -lL .safe
’ reported as an error, it simply outputs nothing. -
-d
Delete all existing keymaps and reset to the default state. -
-D
keymap
...
Delete the namedkeymap
s. -
-A
old-keymap new-keymap
Make thenew-keymap
name an alias forold-keymap
, 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 thenew-keymap
name, it is deleted. -
-N
new-keymap
[old-keymap
]
Create a new keymap, namednew-keymap
. If a keymap already has that name, it is deleted. If anold-keymap
name is given, the new keymap is initialized to be a duplicate of it, otherwise the new keymap will be empty.
To use a newly created keymap, it should be linked to main
. Hence the
sequence of commands to create and use a new keymap ‘mymap
’
initialized from the emacs
keymap (which remains unchanged) is:
bindkey -N mymap emacs
bindkey -A mymap main
Note that while ‘bindkey -A
newmap
main
’ will work when newmap
is emacs
or viins
, it will not work for vicmd
, as switching from
vi insert to command mode becomes impossible.
The following operations act on the ‘main
’ keymap if no keymap
selection option was given:
-
-m
Add the built-in set of meta-key bindings to the selected keymap. Only keys that are unbound or bound toself-insert
are affected. -
-r
in-string
...
Unbind the specifiedin-string
s in the selected keymap. This is exactly equivalent to binding the strings toundefined-key
.When
-R
is also used, interpret thein-string
s as ranges.When
-p
is also used, thein-string
s specify prefixes. Any binding that has the givenin-string
as a prefix, not including the binding for thein-string
itself, if any, will be removed. For example,bindkey -rpM viins '^['
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
vi-cmd-mode
). This is incompatible with the option-R
. -
-s
in-string out-string
...
Bind eachin-string
to eachout-string
. Whenin-string
is typed,out-string
will be pushed back and treated as input to the line editor. When-R
is also used, interpret thein-string
s as ranges.Note that both
in-string
andout-string
are subject to the same form of interpretation, as described below. -
in-string command
...
Bind eachin-string
to eachcommand
. When-R
is used, interpret thein-string
s as ranges. -
[
in-string
]
List key bindings. If anin-string
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-e
or-v
option is used alone, the keymap is not displayed - the implicit linking of keymaps is the only thing that happens.)When the option
-p
is used, thein-string
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.When the
-L
option is used, the list is in the form ofbindkey
commands to create the key bindings.
When the -R
option is used as noted above, a valid range consists of
two characters, with an optional ‘-
’ between them. All characters
between the two specified, inclusive, are bound as specified.
For either in-string
or out-string
, the following escape sequences
are recognised:
-
\a
bell character -
\b
backspace -
\e
,\E
escape -
\f
form feed -
\n
linefeed (newline) -
\r
carriage return -
\t
horizontal tab -
\v
vertical tab -
\``NNN
character code in octal -
\x``NN
character code in hexadecimal -
\u``NNNN
unicode character code in hexadecimal -
\U``NNNNNNNN
unicode character code in hexadecimal -
\M
[-
]X
character with meta bit set -
\C
[-
]X
control character -
^``X
control character
In all other cases, ‘\
’ escapes the following character. Delete is
written as ‘^?
’. Note that ‘\M^?
’ and ‘^\M?
’ are not the same, and
that (unlike emacs), the bindings ‘\M-``X
’ and ‘\e``X
’ are entirely
distinct, although they are initialized to the same bindings by
‘bindkey -m
’.
vared
[ -Aacghe
] [ -p
prompt
] [ -r
rprompt
]
[ -M
main-keymap
] [ -m
vicmd-keymap
]
[ -i
init-widget
] [ -f
finish-widget
]
[ -t
tty
] name
The value of the parameter name
is loaded into the edit buffer, and
the line editor is invoked. When the editor exits, name
is set to the
string value returned by the editor. When the -c
flag is given, the
parameter is created if it doesn’t already exist. The -a
flag may be
given with -c
to create an array parameter, or the -A
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
-g
flag may be given to suppress warnings from the
WARN_CREATE_GLOBAL
and WARN_NESTED_VAR
options.
If an array or array slice is being edited, separator characters as
defined in $IFS
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.
Individual elements of existing array or associative array parameters
may be edited by using subscript syntax on name
. New elements are
created automatically, even without -c
.
If the -p
flag is given, the following string will be taken as the
prompt to display at the left. If the -r
flag is given, the following
string gives the prompt to display at the right. If the -h
flag is
specified, the history can be accessed from ZLE. If the -e
flag is
given, typing ^D
(Control-D) on an empty line causes vared
to exit
immediately with a non-zero return value.
The -M
option gives a keymap to link to the main
keymap during
editing, and the -m
option gives a keymap to link to the vicmd
keymap during editing. For vi-style editing, this allows a pair of
keymaps to override viins
and vicmd
. For emacs-style editing, only
-M
is normally needed but the -m
option may still be used. On exit,
the previous keymaps will be restored.
Vared
calls the usual ‘zle-line-init
’ and ‘zle-line-finish
’ hooks
before and after it takes control. Using the -i
and -f
options, it
is possible to replace these with other custom widgets.
If ‘-t
tty
’ is given, tty
is the name of a terminal device to be
used instead of the default /dev/tty
. If tty
does not refer to a
terminal an error is reported.
zle
zle
-l
[ -L
| -a
] [ string
... ]
zle
-D
widget
...
zle
-A
old-widget
new-widget
zle
-N
widget
[ function
]
zle
-f
flag
[ flag
... ]
zle
-C
widget
completion-widget
function
zle
-R
[ -c
] [ display-string
] [ string
... ]
zle
-M
string
zle
-U
string
zle
-K
keymap
zle
-F
[ -L
| -w
] [ fd
[ handler
] ]
zle
-I
zle
-T
[ tc
function
| -r
tc
| -L
]
zle
widget
[ -n
num
] [ -Nw
] [ -K
keymap
] args
...
The zle
builtin performs a number of different actions concerning ZLE.
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.
Otherwise, which operation it performs depends on its options:
-
-l
[-L
|-a
] [string
]
List all existing user-defined widgets. If the-L
option is used, list in the form ofzle
commands to create the widgets.When combined with the
-a
option, all widget names are listed, including the builtin ones. In this case the-L
option is ignored.If at least one
string
is given, and-a
is present or-L
is not used, nothing will be printed. The return status will be zero if allstring
s are names of existing widgets and non-zero if at least onestring
is not a name of a defined widget. If-a
is also present, all widget names are used for the comparison including builtin widgets, else only user-defined widgets are used.If at least one
string
is present and the-L
option is used, user-defined widgets matching anystring
are listed in the form ofzle
commands to create the widgets. -
-D
widget
...
Delete the namedwidget
s. -
-A
old-widget
new-widget
Make thenew-widget
name an alias forold-widget
, 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 thenew-widget
name, it is deleted. -
-N
widget
[function
]
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 shellfunction
is called. If no function name is specified, it defaults to the same name as the widget. For further information, see Widgets. -
-f
flag
[flag
... ]
Set various flags on the running widget. Possible values forflag
are:yank
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 setYANK_START
andYANK_END
correctly.yankbefore
does the same but is used when the yanked text appears after the cursor.kill
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 ‘zle -f kill
’ to retain this effect.vichange
for indicating that the widget represents a vi change that can be repeated as a whole with ‘vi-repeat-change
’. The flag should be set early in the function before inspecting the value ofNUMERIC
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. -
-C
widget
completion-widget
function
Create a user-defined completion widget namedwidget
. The completion widget will behave like the built-in completion-widget whose name is given ascompletion-widget
. To generate the completions, the shell functionfunction
will be called. For further information, see Completion Widgets. -
-R
[-c
] [display-string
] [string
... ]
Redisplay the command line; this is to be called from within a user-defined widget to allow changes to become visible. If adisplay-string
is given and not empty, this is shown in the status line (immediately below the line being edited).If the optional
string
s are given they are listed below the prompt in the same way as completion lists are printed. If nostring
s are given but the-c
option is used such a list is cleared.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.
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.
The status is zero if zle was active, else one.
-
-M
string
As with the-R
option, thestring
will be displayed below the command line; unlike the-R
option, the string will not be put into the status line but will instead be printed normally below the prompt. This means that thestring
will still be displayed after the widget returns (until it is overwritten by subsequent commands). -
-U
string
This pushes the characters in thestring
onto the input stack of ZLE. After the widget currently executed finishes ZLE will behave as if the characters in thestring
were typed by the user.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
string
will be processed in the order in which they appear in the string. -
-K
keymap
Selects the keymap namedkeymap
. An error message will be displayed if there is no such keymap.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 ‘
main
’ keymap selected. -
-F
[-L
|-w
] [fd
[handler
] ]
Only available if your system supports one of the ‘poll’ or ‘select’ system calls; most modern systems do.Installs
handler
(the name of a shell function) to handle input from file descriptorfd
. Installing a handler for anfd
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 thisfd
is actually readable when installing the handler. The user must make their own arrangements for handling the file descriptor when zle is not active.When zle is attempting to read data, it will examine both the terminal and the list of handled
fd
’s. If data becomes available on a handledfd
, zle callshandler
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: ‘hup
’ for a disconnect, ‘nval
’ for a closed or otherwise invalid descriptor, or ‘err
’ for any other condition. Systems that support only the ‘select’ system call always use ‘err
’.If the option
-w
is also given, thehandler
is instead a line editor widget, typically a shell function made into a widget using ‘zle -N
’. In that casehandler
can use all the facilities of zle to update the current editing line. Note, however, that as handlingfd
takes place at a low level changes to the display will not automatically appear; the widget should call ‘zle -R
’ 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.If either type of handler produces output to the terminal, it should call ‘
zle -I
’ before doing so (see below). Handlers should not attempt to read from the terminal.If no
handler
is given, but anfd
is present, any handler for thatfd
is removed. If there is none, an error message is printed and status 1 is returned.If no arguments are given, or the
-L
option is supplied, a list of handlers is printed in a form which can be stored for later execution.An
fd
(but not ahandler
) may optionally be given with the-L
option; in this case, the function will list the handler if any, else silently return status 1.Note that this feature should be used with care. Activity on one of the
fd
’s which is not properly handled can cause the terminal to become unusable. Removing anfd
handler from within a signal trap may causeHere is a simple example of using this feature. A connection to a remote TCP port is created using the ztcp command; see The zsh/net/tcp Module. 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.
if ztcp pwspc 2811; then tcpfd=$REPLY handler() { zle -I local line if ! read -r line <&$1; then # select marks this fd if we reach EOF, # so handle this specially. print "[Read on fd $1 failed, removing.]" >&2 zle -F $1 return 1 fi print -r - $line } zle -F $tcpfd handler fi
-
-I
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:TRAPUSR1() { # Invalidate zle display [[ -o zle ]] && zle -I # Show output print Hello }
In general, the trap function may need to test whether zle is active before using this method (as shown in the example), since the
zsh/zle
module may not even be loaded; if it is not, the command can be skipped.It is possible to call ‘
zle -I
’ several times before control is returned to the editor; the display will only be invalidated the first time to minimise disruption.Note that there are normally better ways of manipulating the display from within zle widgets; see, for example, ‘
zle -R
’ above.The returned status is zero if zle was invalidated, even though this may have been by a previous call to ‘
zle -I
’ or by a system notification. To test if a zle widget may be called at this point, executezle
with no arguments and examine the return status. -
-T
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.‘
zle -T
transformation
func
’ specifies that the giventransformation
(see below) is effected by shell functionfunc
.‘
zle -Tr
transformation
’ removes the giventransformation
if it was present (it is not an error if none was).‘
zle -TL
’ can be used to list all transformations currently in operation.Currently the only transformation is
tc
. 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 variableREPLY
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. -
widget
[-n
num
] [-Nw
] [-K
keymap
]args
...
Invoke the specifiedwidget
. This can only be done when ZLE is active; normally this will be within a user-defined widget.With the options
-n
and-N
, the current numeric argument will be saved and then restored after the call towidget
; ‘-n
num
’ sets the numeric argument temporarily tonum
, while ‘-N
’ sets it to the default, i.e. as if there were none.With the option
-K
,keymap
will be used as the current keymap during the execution of the widget. The previous keymap will be restored when the widget exits.Normally, calling a widget in this way does not set the special parameter
WIDGET
and related parameters, so that the environment appears as if the top-level widget called by the user were still active. With the option-w
,WIDGET
and related parameters are set to reflect the widget being executed by thezle
call.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
-``-
. 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, thehistory-search-forward
and-backward
and the corresponding functions prefixed byvi-
, and byuniversal-argument
. No error is flagged if the command does not use the arguments, or only uses some of them.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.
A non-zero return status causes the shell to beep when the widget exits, unless the
BEEP
options was unset or the widget was called via thezle
command. Thus if a user defined widget requires an immediate beep, it should call thebeep
widget directly.
18.4 Widgets
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.
The standard widgets built into ZLE are listed in Standard Widgets
below. Other built-in widgets can be defined by other modules (see Zsh
Modules). Each built-in widget has two
names: its normal canonical name, and the same name preceded by a ‘.
’.
The ‘.
’ 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.
User-defined widgets are defined using ‘zle -N
’, 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 ‘.
’.
18.5 User-Defined Widgets
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 zle
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 read -k
or read -q
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.
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 local
.
Inside completion widgets and traps called while ZLE is active, these parameters are available read-only.
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:
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
}
}
BUFFER
(scalar)
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.
BUFFERLINES
(integer)
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.
CONTEXT
(scalar)
The context in which zle was called to read a line; read-only. One of the values:
-
start
The start of a command line (at promptPS1
). -
cont
A continuation to a command line (at promptPS2
). -
select
In aselect
loop (at promptPS3
). -
vared
Editing a variable invared
.
CURSOR
(integer)
The offset of the cursor, within the edit buffer. This is in the range 0
to $#BUFFER
, and is by definition equal to $#LBUFFER
. Attempts to
move the cursor outside the buffer will result in the cursor being moved
to the appropriate end of the buffer.
CUTBUFFER
(scalar)
The last item cut using one of the ‘kill-
’ commands; the string which
the next yank would insert in the line. Later entries in the kill ring
are in the array killring
. Note that the command ‘zle copy-region-as-kill
string
’ 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.
HISTNO
(integer)
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 HISTCMD
, which always gives the
number of the history line being added to the main shell’s history.
HISTNO
refers to the line being retrieved within zle.
ISEARCHMATCH_ACTIVE
(integer)
ISEARCHMATCH_START
(integer)
ISEARCHMATCH_END
(integer)
ISEARCHMATCH_ACTIVE
indicates whether a part of the BUFFER
is
currently matched by an incremental search pattern. ISEARCHMATCH_START
and ISEARCHMATCH_END
give the location of the matched part and are in
the same units as CURSOR
. They are only valid for reading when
ISEARCHMATCH_ACTIVE
is non-zero.
All parameters are read-only.
KEYMAP
(scalar)
The name of the currently selected keymap; read-only.
KEYS
(scalar)
The keys typed to invoke this widget, as a literal string; read-only.
KEYS_QUEUED_COUNT
(integer)
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 PENDING
; the two values are distinct.
killring
(array)
The array of previously killed items, with the most recently killed
first. This gives the items that would be retrieved by a yank-pop
in
the same order. Note, however, that the most recently killed item is in
$CUTBUFFER
; $killring
shows the array of previous entries.
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 yank-pop
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.
LASTABORTEDSEARCH
(scalar)
The last search string used by an interactive search that was aborted by the user (status 3 returned by the search widget).
LASTSEARCH
(scalar)
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.
LASTWIDGET
(scalar)
The name of the last widget that was executed; read-only.
LBUFFER
(scalar)
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 $LBUFFER
and the old $RBUFFER
.
MARK
(integer)
Like CURSOR
, but for the mark. With vi-mode operators that wait for a
movement command to select a region of text, setting MARK
allows the
selection to extend in both directions from the initial cursor position.
NUMERIC
(integer)
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 zle
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.
PENDING
(integer)
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 KEYS_QUEUED_COUNT
;
the two values are distinct.
PREBUFFER
(scalar)
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.
PREDISPLAY
(scalar)
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.
POSTDISPLAY
(scalar)
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.
RBUFFER
(scalar)
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 $LBUFFER
and the new $RBUFFER
.
REGION_ACTIVE
(integer)
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 Character Highlighting.
region_highlight
(array)
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
POSTDISPLAY
are possible, but note that the P
flag is needed for
character indexing to include PREDISPLAY
.
Each string consists of the following parts:
- Optionally, a ‘
P
’ to signify that the start and end offset that follow include any string set by thePREDISPLAY
special parameter; this is needed if the predisplay string itself is to be highlighted. Whitespace may follow the ‘P
’. - A start offset in the same units as
CURSOR
, terminated by whitespace. - An end offset in the same units as
CURSOR
, terminated by whitespace. - A highlight specification in the same format as used for contexts in
the parameter
zle_highlight
, see Character Highlighting; for example,standout
orfg=red,bold
.
For example,
region_highlight=("P0 20 bold")
specifies that the first twenty characters of the text including any predisplay string should be highlighted in bold.
Note that the effect of region_highlight
is not saved and disappears
as soon as the line is accepted.
The final highlighting on the command line depends on both
region_highlight
and zle_highlight
; see Character
Highlighting for details.
registers
(associative array)
The contents of each of the vi register buffers. These are typically set
using vi-set-buffer
followed by a delete, change or yank command.
SUFFIX_ACTIVE
(integer)
SUFFIX_START
(integer)
SUFFIX_END
(integer)
SUFFIX_ACTIVE
indicates whether an auto-removable completion suffix is
currently active. SUFFIX_START
and SUFFIX_END
give the location of
the suffix and are in the same units as CURSOR
. They are only valid
for reading when SUFFIX_ACTIVE
is non-zero.
All parameters are read-only.
UNDO_CHANGE_NO
(integer)
A number representing the state of the undo history. The only use of
this is passing as an argument to the undo
widget in order to undo
back to the recorded point. Read-only.
UNDO_LIMIT_NO
(integer)
A number corresponding to an existing change in the undo history;
compare UNDO_CHANGE_NO
. If this is set to a value greater than zero,
the undo
command will not allow the line to be undone beyond the given
change number. It is still possible to use ‘zle undo
change
’ in a
widget to undo beyond that point; in that case, it will not be possible
to undo at all until UNDO_LIMIT_NO
is reduced. Set to 0 to disable the
limit.
A typical use of this variable in a widget function is as follows (note the additional function scope is required):
() {
local UNDO_LIMIT_NO=$UNDO_CHANGE_NO
# Perform some form of recursive edit.
}
WIDGET
(scalar)
The name of the widget currently being executed; read-only.
WIDGETFUNC
(scalar)
The name of the shell function that implements a widget defined with
either zle -N
or zle -C
. In the former case, this is the second
argument to the zle -N
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 zle -C
command that defined the widget.
Read-only.
WIDGETSTYLE
(scalar)
Describes the implementation behind the completion widget currently
being executed; the second argument that followed zle -C
when the
widget was defined. This is the name of a builtin completion widget. For
widgets defined with zle -N
this is set to the empty string.
Read-only.
YANK_ACTIVE
(integer)
YANK_START
(integer)
YANK_END
(integer)
YANK_ACTIVE
indicates whether text has just been yanked (pasted) into
the buffer. YANK_START
and YANK_END
give the location of the pasted
text and are in the same units as CURSOR
. They are only valid for
reading when YANK_ACTIVE
is non-zero. They can also be assigned by
widgets that insert text in a yank-like fashion, for example wrappers of
bracketed-paste
. See also zle -f
.
YANK_ACTIVE
is read-only.
ZLE_RECURSIVE
(integer)
Usually zero, but incremented inside any instance of recursive-edit
.
Hence indicates the current recursion level.
ZLE_RECURSIVE
is read-only.
ZLE_STATE
(scalar)
Contains a set of space-separated words that describe the current zle
state.
Currently, the states shown are the insert mode as set by the
overwrite-mode
or vi-replace
widgets and whether history commands
will visit imported entries as controlled by the set-local-history
widget. The string contains ‘insert
’ if characters to be inserted on
the command line move existing characters to the right or ‘overwrite
’
if characters to be inserted overwrite existing characters. It contains
‘localhistory
’ if only local history commands will be visited or
‘globalhistory
’ if imported history commands will also be visited.
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:
if [[ $ZLE_STATE == *globalhistory*insert* ]]; then ...; fi
18.5.1 Special Widgets
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.
zle-isearch-exit
Executed at the end of incremental search at the point where the isearch
prompt is removed from the display. See zle-isearch-update
for an
example.
zle-isearch-update
Executed within incremental search when the display is about to be
redrawn. Additional output below the incremental search prompt can be
generated by using ‘zle -M
’ within the widget. For example,
zle-isearch-update() { zle -M "Line $HISTNO"; }
zle -N zle-isearch-update
Note the line output by ‘zle -M
’ is not deleted on exit from
incremental search. This can be done from a zle-isearch-exit
widget:
zle-isearch-exit() { zle -M ""; }
zle -N zle-isearch-exit
zle-line-pre-redraw
Executed whenever the input line is about to be redrawn, providing an opportunity to update the region_highlight array.
zle-line-init
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.
zle-line-init() { zle -K vicmd; }
zle -N zle-line-init
(The command inside the function sets the keymap directly; it is
equivalent to zle vi-cmd-mode
.)
zle-line-finish
This is similar to zle-line-init
but is executed every time the line
editor has finished reading a line of input.
zle-history-line-set
Executed when the history line changes.
zle-keymap-select
Executed every time the keymap changes, i.e. the special parameter
KEYMAP
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.
The value $KEYMAP
within the function reflects the new keymap. The old
keymap is passed as the sole argument.
This can be used for detecting switches between the vi command (vicmd
)
and insert (usually main
) keymaps.
18.6 Standard Widgets
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
‘emacs
’, ‘vicmd
’ and ‘viins
’ keymaps, respectively).
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 viins
keymap, the initial escape character of the
sequences serves also to return to the vicmd
keymap: whether this
happens is determined by the KEYTIMEOUT
parameter, see
Parameters.
18.6.1 Movement
vi-backward-blank-word
(unbound) (B
) (unbound)
Move backward one word, where a word is defined as a series of non-blank characters.
vi-backward-blank-word-end
(unbound) (gE
) (unbound)
Move to the end of the previous word, where a word is defined as a series of non-blank characters.
backward-char
(^B ESC-[D
) (unbound) (unbound)
Move backward one character.
vi-backward-char
(unbound) (^H h ^?
) (ESC-[D
)
Move backward one character, without changing lines.
backward-word
(ESC-B ESC-b
) (unbound) (unbound)
Move to the beginning of the previous word.
emacs-backward-word
Move to the beginning of the previous word.
vi-backward-word
(unbound) (b
) (unbound)
Move to the beginning of the previous word, vi-style.
vi-backward-word-end
(unbound) (ge
) (unbound)
Move to the end of the previous word, vi-style.
beginning-of-line
(^A
) (unbound) (unbound)
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.
vi-beginning-of-line
Move to the beginning of the line, without changing lines.
down-line
(unbound) (unbound) (unbound)
Move down a line in the buffer.
end-of-line
(^E
) (unbound) (unbound)
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.
vi-end-of-line
(unbound) ($
) (unbound)
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.
vi-forward-blank-word
(unbound) (W
) (unbound)
Move forward one word, where a word is defined as a series of non-blank characters.
vi-forward-blank-word-end
(unbound) (E
) (unbound)
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.
forward-char
(^F ESC-[C
) (unbound) (unbound)
Move forward one character.
vi-forward-char
(unbound) (space l
) (ESC-[C
)
Move forward one character.
vi-find-next-char
(^X^F
) (f
) (unbound)
Read a character from the keyboard, and move to the next occurrence of it in the line.
vi-find-next-char-skip
(unbound) (t
) (unbound)
Read a character from the keyboard, and move to the position just before the next occurrence of it in the line.
vi-find-prev-char
(unbound) (F
) (unbound)
Read a character from the keyboard, and move to the previous occurrence of it in the line.
vi-find-prev-char-skip
(unbound) (T
) (unbound)
Read a character from the keyboard, and move to the position just after the previous occurrence of it in the line.
vi-first-non-blank
(unbound) (^
) (unbound)
Move to the first non-blank character in the line.
vi-forward-word
(unbound) (w
) (unbound)
Move forward one word, vi-style.
forward-word
(ESC-F ESC-f
) (unbound) (unbound)
Move to the beginning of the next word. The editor’s idea of a word is
specified with the WORDCHARS
parameter.
emacs-forward-word
Move to the end of the next word.
vi-forward-word-end
(unbound) (e
) (unbound)
Move to the end of the next word.
vi-goto-column
(ESC-|
) (|
) (unbound)
Move to the column specified by the numeric argument.
vi-goto-mark
(unbound) (‘
) (unbound)
Move to the specified mark.
vi-goto-mark-line
(unbound) (’
) (unbound)
Move to beginning of the line containing the specified mark.
vi-repeat-find
(unbound) (;
) (unbound)
Repeat the last vi-find
command.
vi-rev-repeat-find
(unbound) (,
) (unbound)
Repeat the last vi-find
command in the opposite direction.
up-line
(unbound) (unbound) (unbound)
Move up a line in the buffer.
18.6.2 History Control
beginning-of-buffer-or-history
(ESC-<
) (gg
) (unbound)
Move to the beginning of the buffer, or if already there, move to the first event in the history list.
beginning-of-line-hist
Move to the beginning of the line. If already at the beginning of the buffer, move to the previous history line.
beginning-of-history
Move to the first event in the history list.
down-line-or-history
(^N ESC-[B
) (j
) (ESC-[B
)
Move down a line in the buffer, or if already at the bottom line, move to the next event in the history list.
vi-down-line-or-history
(unbound) (+
) (unbound)
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.
down-line-or-search
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.
If called from a function by the zle
command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.
down-history
(unbound) (^N
) (unbound)
Move to the next event in the history list.
history-beginning-search-backward
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.
end-of-buffer-or-history
(ESC->
) (unbound) (unbound)
Move to the end of the buffer, or if already there, move to the last event in the history list.
end-of-line-hist
Move to the end of the line. If already at the end of the buffer, move to the next history line.
end-of-history
Move to the last event in the history list.
vi-fetch-history
(unbound) (G
) (unbound)
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).
history-incremental-search-backward
(^R ^Xr
) (unbound) (unbound)
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 ‘^
’ 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 send-break
command.
A restricted set of editing functions is available in the mini-buffer.
Keys are looked up in the special isearch
keymap, and if not found
there in the main keymap (note that by default the isearch
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:
-
accept-and-hold
accept-and-infer-next-history
accept-line
accept-line-and-down-history
Perform the usual function after exiting incremental search. The command line displayed is executed. -
backward-delete-char
vi-backward-delete-char
Back up one place in the search history. If the search has been repeated this does not immediately erase a character in the minibuffer. -
accept-search
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. -
backward-delete-word
backward-kill-word
vi-backward-kill-word
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 repeatingbackward-delete-char
. -
clear-screen
Clear the screen, remaining in incremental search mode. -
history-incremental-search-backward
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. -
history-incremental-search-forward
Invert the sense of the search. -
magic-space
Inserts a non-magical space. -
quoted-insert
vi-quoted-insert
Quote the character to insert into the minibuffer. -
redisplay
Redisplay the command line, remaining in incremental search mode. -
vi-cmd-mode
Select the ‘vicmd
’ keymap; the ‘main
’ keymap (insert mode) will be selected initially.In addition, the modifications that were made while in vi insert mode are merged to form a single undo event.
-
vi-repeat-search
vi-rev-repeat-search
Repeat the search. The direction of the search is indicated in the mini-buffer.
Any character that is not bound to one of the above functions, or
self-insert
or self-insert-unmeta
, will cause the mode to be exited.
The character is then looked up and executed in the keymap in effect at
that point.
When called from a widget function by the zle
command, the incremental
search commands can take a string argument. This will be treated as a
string of keys, as for arguments to the bindkey
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,
zle history-incremental-search-backward forceps
will search backwards for forceps
, leaving the minibuffer containing
the string ‘forceps
’.
history-incremental-search-forward
(^S ^Xs
) (unbound) (unbound)
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 ‘^
’ to
anchor the search to the beginning of the line. The functions available
in the mini-buffer are the same as for
history-incremental-search-backward
.
history-incremental-pattern-search-backward
history-incremental-pattern-search-forward
These widgets behave similarly to the corresponding widgets with no
-pattern
, 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 Filename
Generation 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 ‘^
’ to anchor the search to the beginning of the line.
The prompt changes to indicate an invalid pattern; this may simply indicate the pattern is not yet complete.
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.
history-search-backward
(ESC-P ESC-p
) (unbound) (unbound)
Search backward in the history for a line beginning with the first word in the buffer.
If called from a function by the zle
command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.
vi-history-search-backward
(unbound) (/
) (unbound)
Search backward in the history for a specified string. The string may
begin with ‘^
’ to anchor the search to the beginning of the line.
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: accept-line
,
backward-delete-char
, vi-backward-delete-char
, backward-kill-word
,
vi-backward-kill-word
, clear-screen
, redisplay
, quoted-insert
and vi-quoted-insert
.
vi-cmd-mode
is treated the same as accept-line, and magic-space
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.
If called from a function by the zle
command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.
history-search-forward
(ESC-N ESC-n
) (unbound) (unbound)
Search forward in the history for a line beginning with the first word in the buffer.
If called from a function by the zle
command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.
vi-history-search-forward
(unbound) (?
) (unbound)
Search forward in the history for a specified string. The string may
begin with ‘^
’ to anchor the search to the beginning of the line. The
functions available in the mini-buffer are the same as for
vi-history-search-backward
. Argument handling is also the same as for
that command.
infer-next-history
(^X^N
) (unbound) (unbound)
Search in the history list for a line matching the current one and fetch the event following it.
insert-last-word
(ESC-_ ESC-.
) (unbound) (unbound)
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.
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 ‘-``-
’ argument to avoid confusing them with
options.
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.
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
insert-last-word
.
For example, the default behaviour of the command corresponds to
zle insert-last-word -- -1 -1
while the command
zle insert-last-word -- -1 1 -
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.
vi-repeat-search
(unbound) (n
) (unbound)
Repeat the last vi history search.
vi-rev-repeat-search
(unbound) (N
) (unbound)
Repeat the last vi history search, but in reverse.
up-line-or-history
(^P ESC-[A
) (k
) (ESC-[A
)
Move up a line in the buffer, or if already at the top line, move to the previous event in the history list.
vi-up-line-or-history
(unbound) (-
) (unbound)
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.
up-line-or-search
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.
If called from a function by the zle
command with arguments, the first
argument is taken as the string for which to search, rather than the
first word in the buffer.
up-history
(unbound) (^P
) (unbound)
Move to the previous event in the history list.
history-beginning-search-forward
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.
set-local-history
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.
18.6.3 Modifying Text
vi-add-eol
(unbound) (A
) (unbound)
Move to the end of the line and enter insert mode.
vi-add-next
(unbound) (a
) (unbound)
Enter insert mode after the current cursor position, without changing lines.
backward-delete-char
(^H ^?
) (unbound) (unbound)
Delete the character behind the cursor.
vi-backward-delete-char
(unbound) (X
) (^H
)
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.
backward-delete-word
Delete the word behind the cursor.
backward-kill-line
Kill from the beginning of the line to the cursor position.
backward-kill-word
(^W ESC-^H ESC-^?
) (unbound) (unbound)
Kill the word behind the cursor.
vi-backward-kill-word
(unbound) (unbound) (^W
)
Kill the word behind the cursor, without going past the point where insert mode was last entered.
capitalize-word
(ESC-C ESC-c
) (unbound) (unbound)
Capitalize the current word and move past it.
vi-change
(unbound) (c
) (unbound)
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 vi-change
, change the current line.
For compatibility with vi, if the command is vi-forward-word
or
vi-forward-blank-word
, the whitespace after the word is not included.
If you prefer the more consistent behaviour with the whitespace included
use the following key binding:
bindkey -a -s cw dwi
vi-change-eol
(unbound) (C
) (unbound)
Kill to the end of the line and enter insert mode.
vi-change-whole-line
(unbound) (S
) (unbound)
Kill the current line and enter insert mode.
copy-region-as-kill
(ESC-W ESC-w
) (unbound) (unbound)
Copy the area from the cursor to the mark to the kill buffer.
If called from a ZLE widget function in the form ‘zle copy-region-as-kill
string
’ then string
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.
copy-prev-word
(ESC-^_
) (unbound) (unbound)
Duplicate the word to the left of the cursor.
copy-prev-shell-word
Like copy-prev-word
, but the word is found by using shell parsing,
whereas copy-prev-word
looks for blanks. This makes a difference when
the word is quoted and contains spaces.
vi-delete
(unbound) (d
) (unbound)
Read a movement command from the keyboard, and kill from the cursor
position to the endpoint of the movement. If the command is vi-delete
,
kill the current line.
delete-char
Delete the character under the cursor.
vi-delete-char
(unbound) (x
) (unbound)
Delete the character under the cursor, without going past the end of the line.
delete-word
Delete the current word.
down-case-word
(ESC-L ESC-l
) (unbound) (unbound)
Convert the current word to all lowercase and move past it.
vi-down-case
(unbound) (gu
) (unbound)
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 vi-down-case
, swap the case of all
characters on the current line.
kill-word
(ESC-D ESC-d
) (unbound) (unbound)
Kill the current word.
gosmacs-transpose-chars
Exchange the two characters behind the cursor.
vi-indent
(unbound) (>
) (unbound)
Indent a number of lines.
vi-insert
(unbound) (i
) (unbound)
Enter insert mode.
vi-insert-bol
(unbound) (I
) (unbound)
Move to the first non-blank character on the line and enter insert mode.
vi-join
(^X^J
) (J
) (unbound)
Join the current line with the next one.
kill-line
(^K
) (unbound) (unbound)
Kill from the cursor to the end of the line. If already on the end of the line, kill the newline character.
vi-kill-line
(unbound) (unbound) (^U
)
Kill from the cursor back to wherever insert mode was last entered.
vi-kill-eol
(unbound) (D
) (unbound)
Kill from the cursor to the end of the line.
kill-region
Kill from the cursor to the mark.
kill-buffer
(^X^K
) (unbound) (unbound)
Kill the entire buffer.
kill-whole-line
(^U
) (unbound) (unbound)
Kill the current line.
vi-match-bracket
(^X^B
) (%
) (unbound)
Move to the bracket character (one of {}
, ()
or []
) 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.
vi-open-line-above
(unbound) (O
) (unbound)
Open a line above the cursor and enter insert mode.
vi-open-line-below
(unbound) (o
) (unbound)
Open a line below the cursor and enter insert mode.
vi-oper-swap-case
(unbound) (g~
) (unbound)
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 vi-oper-swap-case
, swap the case of all
characters on the current line.
overwrite-mode
(^X^O
) (unbound) (unbound)
Toggle between overwrite mode and insert mode.
vi-put-before
(unbound) (P
) (unbound)
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.
vi-put-after
(unbound) (p
) (unbound)
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.
put-replace-selection
(unbound) (unbound) (unbound)
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.
quoted-insert
(^V
) (unbound) (unbound)
Insert the next character typed into the buffer literally. An interrupt character will not be inserted.
vi-quoted-insert
(unbound) (unbound) (^Q ^V
)
Display a ‘^
’ at the cursor position, and insert the next character
typed into the buffer literally. An interrupt character will not be
inserted.
quote-line
(ESC-’
) (unbound) (unbound)
Quote the current line; that is, put a ‘’
’ character at the beginning
and the end, and convert all ‘’
’ characters to ‘’\’’
’.
quote-region
(ESC-"
) (unbound) (unbound)
Quote the region from the cursor to the mark.
vi-replace
(unbound) (R
) (unbound)
Enter overwrite mode.
vi-repeat-change
(unbound) (.
) (unbound)
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.
vi-replace-chars
(unbound) (r
) (unbound)
Replace the character under the cursor with a character read from the keyboard.
Insert a character into the buffer at the cursor position.
self-insert-unmeta
(ESC-^I ESC-^J ESC-^M
) (unbound) (unbound)
Insert a character into the buffer after stripping the meta bit and converting ^M to ^J.
vi-substitute
(unbound) (s
) (unbound)
Substitute the next character(s).
vi-swap-case
(unbound) (~
) (unbound)
Swap the case of the character under the cursor and move past it.
transpose-chars
(^T
) (unbound) (unbound)
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.
transpose-words
(ESC-T ESC-t
) (unbound) (unbound)
Exchange the current word with the one before it.
With a positive numeric argument N, the word around the cursor, or following it if the cursor is between words, is transposed with the preceding N words. The cursor is put at the end of the resulting group of words.
With a negative numeric argument -N, the effect is the same as using a positive argument N except that the original cursor position is retained, regardless of how the words are rearranged.
vi-unindent
(unbound) (<
) (unbound)
Unindent a number of lines.
vi-up-case
(unbound) (gU
) (unbound)
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 vi-up-case
, swap the case of all characters
on the current line.
up-case-word
(ESC-U ESC-u
) (unbound) (unbound)
Convert the current word to all caps and move past it.
yank
(^Y
) (unbound) (unbound)
Insert the contents of the kill buffer at the cursor position.
yank-pop
(ESC-y
) (unbound) (unbound)
Remove the text just yanked, rotate the kill-ring (the history of
previously killed text) and yank the new top. Only works following
yank
, vi-put-before
, vi-put-after
or yank-pop
.
vi-yank
(unbound) (y
) (unbound)
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 vi-yank
, copy the current line.
vi-yank-whole-line
(unbound) (Y
) (unbound)
Copy the current line into the kill buffer.
vi-yank-eol
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.
18.6.4 Arguments
digit-argument
(ESC-0
..ESC-9
) (1
-9
) (unbound)
Start a new numeric argument, or add to the current one. See also
vi-digit-or-beginning-of-line
. This only works if bound to a key
sequence ending in a decimal digit.
Inside a widget function, a call to this function treats the last key of the key sequence which called the widget as the digit.
neg-argument
(ESC-``-
) (unbound) (unbound)
Changes the sign of the following argument.
universal-argument
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 forward-char
, move forward sixteen spaces; if instead
it is followed by -2
, then forward-char
, move backward two spaces.
Inside a widget function, if passed an argument, i.e. ‘zle universal-argument
num
’, the numeric argument will be set to num
;
this is equivalent to ‘NUMERIC=``num
’.
argument-base
Use the existing numeric argument as a numeric base, which must be in
the range 2 to 36 inclusive. Subsequent use of digit-argument
and
universal-argument
will input a new numeric argument in the given
base. The usual hexadecimal convention is used: the letter a
or A
corresponds to 10, and so on. Arguments in bases requiring digits from
10 upwards are more conveniently input with universal-argument
, since
ESC-a
etc. are not usually bound to digit-argument
.
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:
zle argument-base 16
zle universal-argument
18.6.5 Completion
accept-and-menu-complete
In a menu completion, insert the current completion into the buffer, and advance to the next possible completion.
complete-word
Attempt completion on the current word.
delete-char-or-list
(^D
) (unbound) (unbound)
Delete the character under the cursor. If the cursor is at the end of the line, list possible completions for the current word.
expand-cmd-path
Expand the current command to its full pathname.
expand-or-complete
(TAB
) (unbound) (TAB
)
Attempt shell expansion on the current word. If that fails, attempt completion.
expand-or-complete-prefix
Attempt shell expansion on the current word up to cursor.
expand-history
(ESC-space ESC-!
) (unbound) (unbound)
Perform history expansion on the edit buffer.
expand-word
(^X*
) (unbound) (unbound)
Attempt shell expansion on the current word.
list-choices
(ESC-^D
) (^D =
) (^D
)
List possible completions for the current word.
list-expand
(^Xg ^XG
) (^G
) (^G
)
List the expansion of the current word.
magic-space
Perform history expansion and insert a space into the buffer. This is intended to be bound to space.
menu-complete
Like complete-word
, except that menu completion is used. See the
MENU_COMPLETE
option.
menu-expand-or-complete
Like expand-or-complete
, except that menu completion is used.
reverse-menu-complete
Perform menu completion, like menu-complete
, except that if a menu
completion is already in progress, move to the previous completion
rather than the next.
end-of-list
When a previous completion displayed a list below the prompt, this widget can be used to move the prompt below the list.
18.6.6 Miscellaneous
accept-and-hold
(ESC-A ESC-a
) (unbound) (unbound)
Push the contents of the buffer on the buffer stack and execute it.
accept-and-infer-next-history
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.
accept-line
(^J ^M
) (^J ^M
) (^J ^M
)
Finish editing the buffer. Normally this causes the buffer to be executed as a shell command.
accept-line-and-down-history
(^O
) (unbound) (unbound)
Execute the current line, and push the next history event on the buffer stack.
auto-suffix-remove
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.
This widget is intended to be called from user-defined widgets to enforce a desired suffix-removal behavior.
auto-suffix-retain
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.
This widget is intended to be called from user-defined widgets to enforce a desired suffix-preservation behavior.
beep
Beep, unless the BEEP
option is unset.
bracketed-paste
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.
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.
When a named buffer is specified with vi-set-buffer
("x
), the pasted
text is stored in that named buffer but not inserted.
When called from a widget function as ‘bracketed-paste
name
‘, the
pasted text is assigned to the variable name
and no other processing
is done.
See also the zle_bracketed_paste
parameter.
vi-cmd-mode
(^X^V
) (unbound) (^[
)
Enter command mode; that is, select the ‘vicmd
’ keymap. Yes, this is
bound by default in emacs mode.
vi-caps-lock-panic
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).
clear-screen
(^L ESC-^L
) (^L
) (^L
)
Clear the screen and redraw the prompt.
deactivate-region
Make the current region inactive. This disables vim-style visual selection mode if it is active.
describe-key-briefly
Reads a key sequence, then prints the function bound to that sequence.
exchange-point-and-mark
(^X^X
) (unbound) (unbound)
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.
execute-named-cmd
(ESC-x
) (:
) (unbound)
Read the name of an editor command and execute it. Aliasing this widget
with ‘zle -A
’ or replacing it with ‘zle -N
’ has no effect when
interpreting key bindings, but ‘zle execute-named-cmd
’ will invoke
such an alias or replacement.
A restricted set of editing functions is available in the mini-buffer.
Keys are looked up in the special command
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 executed-named-cmd
environment and cannot be
replaced by user defined widgets, nor can the set of functions be
extended. The allowed functions are: backward-delete-char
,
vi-backward-delete-char
, clear-screen
, redisplay
, quoted-insert
,
vi-quoted-insert
, backward-kill-word
, vi-backward-kill-word
,
kill-whole-line
, vi-kill-line
, backward-kill-line
, list-choices
,
delete-char-or-list
, complete-word
, accept-line
,
expand-or-complete
and expand-or-complete-prefix
.
kill-region
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 AUTO_LIST
option is set. Any other character that is not bound
to self-insert
or self-insert-unmeta
will beep and be ignored. The
bindings of the current insert mode will be used.
Currently this command may not be redefined or called by name.
execute-last-named-cmd
(ESC-z
) (unbound) (unbound)
Redo the last function executed with execute-named-cmd
.
Like execute-named-cmd
, this command may not be redefined, but it may
be called by name.
get-line
(ESC-G ESC-g
) (unbound) (unbound)
Pop the top line off the buffer stack and insert it at the cursor position.
pound-insert
(unbound) (#
) (unbound)
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
INTERACTIVE_COMMENTS
option must be set for this to have any
usefulness.
vi-pound-insert
If there is no # character at the beginning of the current line, add
one. If there is one, remove it. The INTERACTIVE_COMMENTS
option must
be set for this to have any usefulness.
push-input
Push the entire current multiline construct onto the buffer stack and
return to the top-level (PS1
) prompt. If the current parser construct
is only a single line, this is exactly like push-line
. Next time the
editor starts up or is popped with get-line
, the construct will be
popped off the top of the buffer stack and loaded into the editing
buffer.
push-line
(^Q ESC-Q ESC-q
) (unbound) (unbound)
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.
push-line-or-edit
At the top-level (PS1
) prompt, equivalent to push-line
. At a
secondary (PS2
) prompt, move the entire current multiline construct
into the editor buffer. The latter is equivalent to push-input
followed by get-line
.
read-command
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
REPLY
. This can be used as the argument of a future zle
command. If
the key sequence is not bound, status 1 is returned; typically, however,
REPLY
is set to undefined-key
to indicate a useless key sequence.
recursive-edit
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 accept-line
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.
The following widget, caps-lock
, serves as an 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 )) && zle send-break
return $stat
This causes typed letters to be inserted capitalised until either
accept-line
(i.e. typically the return key) is typed or the
caps-lock
widget is invoked again; the later is handled by saving the
old definition of caps-lock
as save-caps-lock
and then rebinding it
to invoke accept-line
. Note that an error from the recursive edit is
detected as a non-zero return status and propagated by using the
send-break
widget.
redisplay
(unbound) (^R
) (^R
)
Redisplays the edit buffer.
reset-prompt
(unbound) (unbound) (unbound)
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).
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.
reset-prompt
doesn’t alter the special parameter LASTWIDGET
.
send-break
(^G ESC-^G
) (unbound) (unbound)
Abort the current editor function, e.g. execute-named-command
, or the
editor itself, e.g. if you are in vared
. Otherwise abort the parsing
of the current line; in this case the aborted line is available in the
shell variable ZLE_LINE_ABORTED
. If the editor is aborted from within
vared
, the variable ZLE_VARED_ABORTED
is set.
run-help
(ESC-H ESC-h
) (unbound) (unbound)
Push the buffer onto the buffer stack, and execute the command
‘run-help
cmd
’, where cmd
is the current command. run-help
is
normally aliased to man
.
vi-set-buffer
(unbound) ("
) (unbound)
Specify a buffer to be used in the following command. There are 37
buffers that can be specified: the 26 ‘named’ buffers "a
to "z
, the
‘yank’ buffer "0
, the nine ‘queued’ buffers "1
to "9
and the
‘black hole’ buffer "_
. The named buffers can also be specified as
"A
to "Z
.
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 "_
buffer, nothing happens. This can be useful for deleting text without
affecting any buffers.
If no buffer is specified for a cut or change command, "1
is used, and
the contents of "1
to "8
are each shifted along one buffer; the
contents of "9
is lost. If no buffer is specified for a yank command,
"0
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.
When called from a widget function by the zle
command, the buffer can
optionally be specified with an argument. For example,
zle vi-set-buffer A
vi-set-mark
(unbound) (m
) (unbound)
Set the specified mark at the cursor position.
set-mark-command
(^@
) (unbound) (unbound)
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.
spell-word
(ESC-$ ESC-S ESC-s
) (unbound) (unbound)
Attempt spelling correction on the current word.
split-undo
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, undo
will normally revert as one all the changes made
by a user-defined widget.
undefined-key
This command is executed when a key sequence that is not bound to any command is typed. By default it beeps.
undo
(^_ ^Xu ^X^U
) (u
) (unbound)
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 UNDO_CHANGE_NO
variable;
modifications are undone until that state is reached, subject to any
limit imposed by the UNDO_LIMIT_NO
variable.
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.
redo
(unbound) (^R
) (unbound)
Incrementally redo undone text modifications.
vi-undo-change
(unbound) (unbound) (unbound)
Undo the last text modification. If repeated, redo the modification.
visual-mode
(unbound) (v
) (unbound)
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.
visual-line-mode
(unbound) (V
) (unbound)
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.
what-cursor-position
(^X=
) (ga
) (unbound)
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.
where-is
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 command
keymap, and if not found there in the main keymap.
which-command
(ESC-?
) (unbound) (unbound)
Push the buffer onto the buffer stack, and execute the command
‘which-command
cmd
’. where cmd
is the current command.
which-command
is normally aliased to whence
.
vi-digit-or-beginning-of-line
(unbound) (0
) (unbound)
If the last command executed was a digit as part of an argument, continue the argument. Otherwise, execute vi-beginning-of-line.
18.6.7 Text Objects
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 viopp
and visual
keymaps.
select-a-blank-word
(aW
)
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.
select-a-shell-word
(aa
)
Select the current command argument applying the normal rules for quoting.
select-a-word
(aw
)
Select a word including adjacent blanks, using the normal vi-style word definition. With a numeric argument, multiple words will be selected.
select-in-blank-word
(iW
)
Select a word, where a word is defined as a series of non-blank characters. With a numeric argument, multiple words will be selected.
select-in-shell-word
(ia
)
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.
select-in-word
(iw
)
Select a word, using the normal vi-style word definition. With a numeric argument, multiple words will be selected.
18.7 Character Highlighting
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 zle_highlight
, if it has been set by the user.
If the parameter contains the single entry none
all highlighting is
turned off. Note the parameter is still expected to be an array.
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.
The contexts available for highlighting are the following:
default
Any text within the command line not affected by any other highlighting.
isearch
When one of the incremental history search widgets is active, the area of the command line matched by the search string or pattern.
region
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 set-mark-command
or exchange-point-and-mark
.
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.
special
representation but are shown in a special manner by the line editor. These characters are described below.
suffix
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 (/
) after a directory name. Note
that suffix removal is configurable; the circumstances under which the
suffix will be removed may differ for different completions.
paste
Following a command to paste text, the characters that were inserted.
When region_highlight
is set, the contexts that describe a region —
isearch
, region
, suffix
, and paste
— are applied first, then
region_highlight
is applied, then the remaining zle_highlight
contexts are applied. If a particular character is affected by multiple
specifications, the last specification wins.
zle_highlight
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.
fg_start_code
(\e[3
)
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.
fg_default_code
(9
)
The number to use instead of the colour to reset the default foreground colour.
fg_end_code
(m
)
The end of the escape sequence for the foreground colour.
bg_start_code
(\e[4
)
The start of the escape sequence for the background colour. See
fg_start_code
above.
bg_default_code
(9
)
The number to use instead of the colour to reset the default background colour.
bg_end_code
(m
)
The end of the escape sequence for the background colour.
The available types of highlighting are the following. Note that not all types of highlighting are available on all terminals:
-
none
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. -
fg=``colour
The foreground colour should be set tocolour
, a decimal integer, the name of one of the eight most widely-supported colours or as a ‘#
’ followed by an RGB triplet in hexadecimal format.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
black
,red
,green
,yellow
,blue
,magenta
,cyan
andwhite
, which can be set by name. In addition.default
may be used to set the terminal’s default foreground colour. Abbreviations are allowed;b
orbl
selects black. Some terminals may generate additional colours if thebold
attribute is also present.On recent terminals and on systems with an up-to-date terminal database the number of colours supported may be tested by the command ‘
echotc Co
’; 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).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 ‘
#
’ 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 thezsh/nearcolor
module (see The zsh/nearcolor Module).Colour is also known as color.
-
bg=``colour
The background colour should be set tocolour
. This works similarly to the foreground colour, except the background is not usually affected by the bold attribute. -
bold
The characters in the given context are shown in a bold font. Not all terminals distinguish bold fonts. -
standout
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. -
underline
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.
The characters described above as ‘special’ are as follows. The formatting described here is used irrespective of whether the characters are highlighted:
-
ASCII control characters
Control characters in the ASCII range are shown as ‘^
’ followed by the base character.This item applies to control characters not in the ASCII range, plus other characters as follows. If the
MULTIBYTE
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 optionCOMBINING_CHARS
is on. If the option is off, or if a character appears where a combining character is not valid, the characterangle 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.
-
Invalid multibyte characters
If theMULTIBYTE
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.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).
-
Wrapped double-width characters
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.
If zle_highlight
is not set or no value applies to a particular
context, the defaults applied are equivalent to
zle_highlight=(region:standout special:standout
suffix:bold isearch:underline paste:standout)
i.e. both the region and special characters are shown in standout mode.
Within widgets, arbitrary regions may be highlighted by setting the
special array parameter region_highlight
; see Widgets.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
19 Completion Widgets
19.1 Description
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, Completion
System, 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 compctl
builtin command is described in
Completion Using
compctl.
Completion widgets are defined by the -C
option to the zle
builtin
command provided by the zsh/zle
module (see The zsh/zle
Module). For example,
zle -C complete expand-or-complete completer
defines a widget named ‘complete
’. The second argument is the name of
any of the builtin widgets that handle completions: complete-word
,
expand-or-complete
, expand-or-complete-prefix
, menu-complete
,
menu-expand-or-complete
, reverse-menu-complete
, list-choices
, or
delete-char-or-list
. Note that this will still work even if the widget
in question has been re-bound.
When this newly defined widget is bound to a key using the bindkey
builtin command defined in the zsh/zle
module (Zsh Line
Editor), typing that key will
call the shell function ‘completer
’. 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.
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 expand-or-complete
.
19.2 Completion Special Parameters
The parameters ZLE_REMOVE_SUFFIX_CHARS
and ZLE_SPACE_SUFFIX_CHARS
are used by the completion mechanism, but are not special. See
Parameters Used By The
Shell.
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 compstate
, 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.
CURRENT
This is the number of the current word, i.e. the word the cursor is
currently on in the words
array. Note that this value is only correct
if the ksharrays
option is not set.
IPREFIX
Initially this will be set to the empty string. This parameter functions
like PREFIX
; it contains a string which precedes the one in PREFIX
and is not considered part of the list of matches. Typically, a string
is transferred from the beginning of PREFIX
to the end of IPREFIX
,
for example:
IPREFIX=${PREFIX%%\=*}=
PREFIX=${PREFIX#*=}
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 compset
builtin, see below.
ISUFFIX
As IPREFIX
, but for a suffix that should not be considered part of the
matches; note that the ISUFFIX
string follows the SUFFIX
string.
PREFIX
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.
QIPREFIX
This parameter is read-only and contains the quoted string up to the
word being completed. E.g. when completing ‘"foo
’, this parameter
contains the double quote. If the -q
option of compset
is used (see
below), and the original string was ‘"foo bar
’ with the cursor on the
‘bar
’, this parameter contains ‘"foo
’.
QISUFFIX
Like QIPREFIX
, but containing the suffix.
SUFFIX
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 COMPLETE_IN_WORD
is
set, as otherwise the whole word on the command line is treated as a
prefix.
compstate
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:
all_quotes
The -q
option of the compset
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 ‘compset -q
’ 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 $’``...``’
and a
backslash for strings not starting with a quote character. The first
character in the value always corresponds to the innermost quoting
level.
context
This will be set by the completion code to the overall context in which completion is attempted. Possible values are:
-
array_value
when completing inside the value of an array parameter assignment; in this case thewords
array contains the words inside the parentheses. -
brace_parameter
when completing the name of a parameter in a parameter expansion beginning with${
. This context will also be set when completing parameter flags following${(
; the full command line argument is presented and the handler must test the value to be completed to ascertain that this is the case. -
assign_parameter
when completing the name of a parameter in a parameter assignment. -
command
when completing for a normal command (either in command position or for an argument of the command). -
condition
when completing inside a ‘[[
...]]
’ conditional expression; in this case thewords
array contains only the words inside the conditional expression. -
math
when completing in a mathematical environment such as a ‘((
...))
’ construct. -
parameter
when completing the name of a parameter in a parameter expansion beginning with$
but not${
. -
redirect
when completing after a redirection operator. -
subscript
when completing inside a parameter subscript. -
value
when completing the value of a parameter assignment.
exact
Controls the behaviour when the REC_EXACT
option is set. It will be
set to accept
if an exact match would be accepted, and will be unset
otherwise.
If it was set when at least one match equal to the string on the line was generated, the match is accepted.
exact_string
The string of an exact match if one was found, otherwise unset.
ignored
The number of words that were ignored because they matched one of the
patterns given with the -F
option to the compadd
builtin command.
insert
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 unambiguous
, any prefix common to all
matches is to be inserted; if set to automenu-unambiguous
, the common
prefix is to be inserted and the next invocation of the completion code
may start menu completion (due to the AUTO_MENU
option being set); if
set to menu
or automenu
menu completion will be started for the
matches currently generated (in the latter case this will happen because
the AUTO_MENU
is set). The value may also contain the string ‘tab
’
when the completion code would normally not really do completion, but
only insert the TAB character.
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 ‘-1
’
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.
Both menu
and automenu
may also specify the number of the match to
insert, given after a colon. For example, ‘menu:2
’ says to start menu
completion, beginning with the second match.
Note that a value containing the substring ‘tab
’ makes the matches
generated be ignored and only the TAB be inserted.
Finally, it may also be set to all
, which makes all matches generated
be inserted into the line.
insert_positions
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.
last_prompt
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 ALWAYS_LAST_PROMPT
option.
list
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
list
, they will always be listed; if it begins with autolist
or
ambiguous
, they will be listed when the AUTO_LIST
or
LIST_AMBIGUOUS
options respectively would normally cause them to be.
If the substring force
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.
The value contains the substring packed
if the LIST_PACKED
option is
set. If this substring is given for all matches added to a group, this
group will show the LIST_PACKED
behavior. The same is done for the
LIST_ROWS_FIRST
option with the substring rows
.
Finally, if the value contains the string explanations
, only the
explanation strings, if any, will be listed and if it contains
messages
, only the messages (added with the -x
option of compadd
)
will be listed. If it contains both explanations
and messages
both
kinds of explanation strings will be listed. It will be set
appropriately on entry to a completion widget and may be changed there.
list_lines
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 BUFFERLINES
special parameter.
list_max
Initially this is set to the value of the LISTMAX
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 LISTMAX
.
nmatches
The number of matches generated and accepted by the completion code so far.
old_insert
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.
As with old_list
, the value of this key will only be used if it is the
string keep
. 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 insert
key specifies that another match should be
inserted, this will be inserted after the old one.
old_list
This is set to yes
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 shown
.
After the widget has exited the value of this key is only used if it was
set to keep
. In this case the completion code will continue to use
this old list. If the widget generated new matches, they will not be
used.
parameter
The name of the parameter when completing in a subscript or in the value of a parameter assignment.
pattern_insert
Normally this is set to menu
, 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.
pattern_match
Locally controls the behaviour given by the GLOB_COMPLETE
option.
Initially it is set to ‘*
’ 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 ‘*
’, then additionally a wildcard ‘*
’
is assumed at the cursor position; if it is empty or unset,
metacharacters will be treated literally.
Note that the matcher specifications given to the compadd
builtin
command are not used if this is set to a non-empty string.
quote
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.
quoting
When completing inside single quotes, this is set to the string
single
; inside double quotes, the string double
; inside backticks,
the string backtick
. Otherwise it is unset.
redirect
The redirection operator when completing in a redirection position, i.e.
one of <
, >
, etc.
restore
This is set to auto
before a function is entered, which forces the
special parameters mentioned above (words
, CURRENT
, PREFIX
,
IPREFIX
, SUFFIX
, and ISUFFIX
) 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.
to_end
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 single
if this will happen when a single unambiguous match was
inserted or match
if it will happen any time a match is inserted (for
example, by menu completion; this is likely to be the effect of the
ALWAYS_TO_END
option).
On exit, it may be set to single
as above. It may also be set to
always
, 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 match
.
unambiguous
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.
unambiguous_cursor
This gives the position the cursor would be placed at if the common
prefix in the unambiguous
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.
unambiguous_positions
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 unambiguous
key.
vared
If completion is called while editing a line using the vared
builtin,
the value of this key is set to the name of the parameter given as an
argument to vared
. This key is only set while a vared
command is
active.
words
This array contains the words present on the command line currently being edited.
19.3 Completion Builtin Commands
compadd
[ -akqQfenUl12C
] [ -F
array
]
[-P
prefix
] [ -S
suffix
]
[-p
hidden-prefix
] [ -s
hidden-suffix
]
[-i
ignored-prefix
] [ -I
ignored-suffix
]
[-W
file-prefix
] [ -d
array
]
[-J
group-name
] [ -X
explanation
] [ -x
message
]
[-V
group-name
] [ -o
[ order
] ]
[-r
remove-chars
] [ -R
remove-func
]
[-D
array
] [ -O
array
] [ -A
array
]
[-E
number
]
[-M
match-spec
] [ -``-
] [ words
... ]
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.
The completion code breaks the string to complete into seven fields in the order:
<ipre><apre><hpre><word><hsuf><asuf><isuf>
The first field is an ignored prefix taken from the command line, the
contents of the IPREFIX
parameter plus the string given with the -i
option. With the -U
option, only the string from the -i
option is
used. The field <apre>
is an optional prefix string given with the
-P
option. The <hpre>
field is a string that is considered part of
the match but that should not be shown when listing completions, given
with the -p
option; for example, functions that do filename generation
might specify a common path prefix this way. <word>
is the part of the
match that should appear in the list of completions, i.e. one of the
words
given at the end of the compadd
command line. The suffixes
<hsuf>
, <asuf>
and <isuf>
correspond to the prefixes <hpre>
,
<apre>
and <ipre>
and are given by the options -s
, -S
and -I
,
respectively.
The supported flags are:
-
-P
prefix
This gives a string to be inserted before the givenwords
. 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. -
-S
suffix
Like-P
, but gives a string to be inserted after the match. -
-p
hidden-prefix
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-U
option is given, this string must be matched as part of the string on the command line. -
-s
hidden-suffix
Like ‘-p
’, but gives a string to insert after the match. -
-i
ignored-prefix
This gives a string to insert into the command line just before any string given with the ‘-P
’ option. Without ‘-P
’ the string is inserted before the string given with ‘-p
’ or directly before the match. -
-I
ignored-suffix
Like-i
, but gives an ignored suffix. -
-a
With this flag thewords
are taken as names of arrays and the possible matches are their values. If only some elements of the arrays are needed, thewords
may also contain subscripts, as in ‘foo[2,-1]
’. -
-k
With this flag thewords
are taken as names of associative arrays and the possible matches are their keys. As for-a
, thewords
may also contain subscripts, as in ‘foo[(R)*bar*]
’. -
-d
array
This adds per-match display strings. Thearray
should contain one element perword
given. The completion code will then display the first element instead of the firstword
, and so on. Thearray
may be given as the name of an array parameter or directly as a space-separated list of words in parentheses.If there are fewer display strings than
words
, the leftoverwords
will be displayed unchanged and if there are more display strings thanwords
, the leftover display strings will be silently ignored. -
-l
This option only has an effect if used together with the-d
option. If it is given, the display strings are listed one per line, not arrayed in columns. -
-o
[order
]
This controls the order in which matches are sorted.order
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.-
match
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-d
option). This is the default if ‘-o
’ is specified but theorder
argument is omitted. -
nosort
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. -
numeric
If the matches include numbers, sort them numerically rather than lexicographically. -
reverse
Arrange the matches backwards by reversing the sort ordering.
-
-
-J
group-name
Gives the name of the group of matches the words should be stored in. -
-V
group-name
Like-J
but naming an unsorted group. This option is identical to the combination of-J
and-o nosort
. -
-1
If given together with the-V
option, makes only consecutive duplicates in the group be removed. If combined with the-J
option, this has no visible effect. Note that groups with and without this flag are in different name spaces. -
-2
If given together with the-J
or-V
option, makes all duplicates be kept. Again, groups with and without this flag are in different name spaces. -
-X
explanation
Theexplanation
string will be printed with the list of matches, above the group currently selected.Within the
explanation
, the following sequences may be used to specify output attributes (see Prompt Expansion): ‘%B
’, ‘%S
’, ‘%U
’, ‘%F
’, ‘%K
’ and their lower case counterparts, as well as ‘%{
...%}
’. ‘%F
’, ‘%K
’ and ‘%{
...%}
’ take arguments in the same form as prompt expansion. (Note that the sequence ‘%G
’ is not available; an argument to ‘%{
’ should be used instead.) The sequence ‘%%
’ produces a literal ‘%
’.These sequences are most often employed by users when customising the
format
style (see Completion System), but they must also be taken into account when writing completion functions, as passing descriptions with unescaped ‘%
’ characters to utility functions such as_arguments
and_message
may produce unexpected results. If arbitrary text is to be passed in a description, it can be escaped using e.g.${my_str//\%/%%}
. -
-x
message
Like-X
, but themessage
will be printed even if there are no matches in the group. -
-q
The suffix given with-S
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. -
-r
remove-chars
This is a more versatile form of the-q
option. The suffix given with-S
or the slash automatically added after completing directories will be automatically removed if the next character typed inserts one of the characters given in theremove-chars
. This string is parsed as a characters class and understands the backslash sequences used by theprint
command. For example, ‘-r "a-z\t"
’ removes the suffix if the next character typed inserts a lower case character or a TAB, and ‘-r "^0-9"
’ removes the suffix if the next character typed inserts anything but a digit. One extra backslash sequence is understood in this string: ‘\-
’ stands for all characters that insert nothing. Thus ‘-S "=" -q
’ is the same as ‘-S "=" -r "= \t\n\-"
’.This option may also be used without the
-S
option; then any automatically added space will be removed when one of the characters in the list is typed. -
-R
remove-func
This is another form of the-r
option. When a suffix has been inserted and the completion accepted, the functionremove-func
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 Zsh Line Editor) to analyse and modify the command line. -
-f
If this flag is given, all of the matches built fromwords
are marked as being the names of files. They are not required to be actual filenames, but if they are, and the optionLIST_TYPES
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. -
-e
This flag can be used to tell the completion code that the matches added are parameter names for a parameter expansion. This will make theAUTO_PARAM_SLASH
andAUTO_PARAM_KEYS
options be used for the matches. -
-W
file-prefix
This string is a pathname that will be prepended to each of the matches formed by the givenwords
together with any prefix specified by the-p
option to form a complete filename for testing. Hence it is only useful if combined with the-f
flag, as the tests will not otherwise be performed. -
-F
array
Specifies an array containing patterns. Words matching one of these patterns are ignored, i.e. not considered to be possible matches.The
array
may be the name of an array parameter or a list of literal patterns enclosed in parentheses and quoted, as in ‘-F "(*?.o *?.h)"
’. If the name of an array is given, the elements of the array are taken as the patterns. -
-Q
This flag instructs the completion code not to quote any metacharacters in the words when inserting them into the command line. -
-M
match-spec
This gives local match specifications as described below in Completion Matching Control. This option may be given more than once. In this case allmatch-spec
s given are concatenated with spaces between them to form the specification string to use. Note that they will only be used if the-U
option is not given. -
-n
Specifies that the words added are to be used as possible matches, but are not to appear in the completion listing. -
-U
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. -
-O
array
If this option is given, thewords
are not added to the set of possible completions. Instead, matching is done as usual and all of thewords
given as arguments that match the string on the command line will be stored in the array parameter whose name is given asarray
. -
-A
array
As the-O
option, except that instead of those of thewords
which match being stored inarray
, the strings generated internally by the completion code are stored. For example, with a matching specification of ‘-M "L:|no="
’, the string ‘nof
’ on the command line and the string ‘foo
’ as one of thewords
, this option stores the string ‘nofoo
’ in the array, whereas the-O
option stores the ‘foo
’ originally given. -
-D
array
As with-O
, thewords
are not added to the set of possible completions. Instead, the completion code tests whether eachword
in turn matches what is on the line. If then
thword
does not match, then
th element of thearray
is removed. Elements for which the correspondingword
is matched are retained. -
-C
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-d
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. -
-E
number
This option addsnumber
empty matches after thewords
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-d
option). And because all but one empty string would otherwise be removed, this option implies the-V
and-2
options (even if an explicit-J
option is given). This can be important to note as it affects the name space into which matches are added. -
-
-``-
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.
Except for the -M
flag, if any of these flags is given more than once,
the first one (and its argument) will be used.
compset -p
number
compset -P
[ number
] pattern
compset -s
number
compset -S
[ number
] pattern
compset -n
begin
[ end
]
compset -N
beg-pat
[ end-pat
]
compset -q
This command simplifies modification of the special parameters, while its return status allows tests on them to be carried out.
The options are:
-
-p
number
If the value of thePREFIX
parameter is at leastnumber
characters long, the firstnumber
characters are removed from it and appended to the contents of theIPREFIX
parameter. -
-P
[number
]pattern
If the value of thePREFIX
parameter begins with anything that matches thepattern
, the matched portion is removed fromPREFIX
and appended toIPREFIX
.Without the optional
number
, the longest match is taken, but ifnumber
is given, anything up to thenumber
th match is moved. If thenumber
is negative, thenumber
th longest match is moved. For example, ifPREFIX
contains the string ‘a=b=c
’, thencompset -P ’*=’
will move the string ‘a=b=
’ into theIPREFIX
parameter, butcompset -P 1 ’*\=’
will move only the string ‘a=
’. -
-s
number
As-p
, but transfer the lastnumber
characters from the value ofSUFFIX
to the front of the value ofISUFFIX
. -
-S
[number
]pattern
As-P
, but match the last portion ofSUFFIX
and transfer the matched portion to the front of the value ofISUFFIX
. -
-n
begin
[end
]
If the current word position as specified by the parameterCURRENT
is greater than or equal tobegin
, anything up to thebegin
th word is removed from thewords
array and the value of the parameterCURRENT
is decremented bybegin
.If the optional
end
is given, the modification is done only if the current word position is also less than or equal toend
. In this case, the words from positionend
onwards are also removed from thewords
array.Both
begin
andend
may be negative to count backwards from the last element of thewords
array. -
-N
beg-pat
[end-pat
]
If one of the elements of thewords
array before the one at the index given by the value of the parameterCURRENT
matches the patternbeg-pat
, all elements up to and including the matching one are removed from thewords
array and the value ofCURRENT
is changed to point to the same word in the changed array.If the optional pattern
end-pat
is also given, and there is an element in thewords
array matching this pattern, the parameters are modified only if the index of this word is higher than the one given by theCURRENT
parameter (so that the matching word has to be after the cursor). In this case, the words starting with the one matchingend-pat
are also removed from thewords
array. Ifwords
contains no word matchingend-pat
, the testing and modification is performed as if it were not given. -
-q
The word currently being completed is split on spaces into separate words, respecting the usual shell quoting conventions. The resulting words are stored in thewords
array, andCURRENT
,PREFIX
,SUFFIX
,QIPREFIX
, andQISUFFIX
are modified to reflect the word part that is completed.
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:
if compset -P '*\='; then ...
This forces anything up to and including the last equal sign to be ignored by the completion code.
compcall
[ -TD
]
This allows the use of completions defined with the compctl
builtin
from within completion widgets. The list of matches will be generated as
if one of the non-widget completion functions (complete-word
, etc.)
had been called, except that only compctl
s given for specific commands
are used. To force the code to try completions defined with the -T
option of compctl
and/or the default completion (whether defined by
compctl -D
or the builtin default) in the appropriate places, the -T
and/or -D
flags can be passed to compcall
.
The return status can be used to test if a matching compctl
definition
was found. It is non-zero if a compctl
was found and zero otherwise.
Note that this builtin is defined by the zsh/compctl
module.
19.4 Completion Condition Codes
The following additional condition codes for use within the [[
...
]]
construct are available in completion widgets. These work on the
special parameters. All of these tests can also be performed by the
compset
builtin, but in the case of the condition codes the contents
of the special parameters are not modified.
-
-prefix
[number
]pattern
true if the test for the-P
option ofcompset
would succeed. -
-suffix
[number
]pattern
true if the test for the-S
option ofcompset
would succeed. -
-after
beg-pat
true if the test of the-N
option with only thebeg-pat
given would succeed. -
-between
beg-pat end-pat
true if the test for the-N
option with both patterns would succeed.
19.5 Completion Matching Control
It is possible by use of the -M
option of the compadd
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 GLOB_COMPLETE
option is set or the
pattern_match
of the compstate
special association is set to a
non-empty string.
The match-spec
given as the argument to the -M
option (see
Completion Builtin Commands) 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.
The forms of match-spec
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.
-
m:``lpat``=``tpat
M:``lpat``=``tpat
Here,lpat
is a pattern that matches on the command line, corresponding totpat
which matches in the trial completion. -
l:``lanchor``|``lpat``=``tpat
L:``lanchor``|``lpat``=``tpat
l:``lanchor``||``ranchor``=``tpat
L:``lanchor``||``ranchor``=``tpat
b:``lpat``=``tpat
B:``lpat``=``tpat
These letters are for patterns that are anchored by another pattern on the left side. Matching forlpat
andtpat
is as form
andM
, but the patternlpat
matched on the command line must be preceded by the patternlanchor
. Thelanchor
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.If no
lpat
is given but aranchor
is, this matches the gap between substrings matched bylanchor
andranchor
. Unlikelanchor
, theranchor
only needs to match the trial completion string.The
b
andB
forms are similar tol
andL
with an empty anchor, but need to match only the beginning of the word on the command line or trial completion, respectively. -
r:``lpat``|``ranchor``=``tpat
R:``lpat``|``ranchor``=``tpat
r:``lanchor``||``ranchor``=``tpat
R:``lanchor``||``ranchor``=``tpat
e:``lpat``=``tpat
E:``lpat``=``tpat
Asl
,L
,b
andB
, with the difference that the command line and trial completion patterns are anchored on the right side. Here an emptyranchor
and thee
andE
forms force the match to the end of the command line or trial completion string. -
x:
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.
Each lpat
, tpat
or anchor
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.
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 !
and ^
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 ‘m:{a-z}={A-Z}
’ (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 =
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.
The standard ‘[:``name``:]
’ forms described for standard shell
patterns (see Filename Generation)
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 [:upper:]
,
[:lower:]
. 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
‘m:{[:lower:]}={[:upper:]}
’. 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 ‘[:``name``:]
’ 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.
The pattern tpat
may also be one or two stars, ‘*
’ or ‘**
’. 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 anchor
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.
Examples:
The keys of the options
association defined by the parameter
module
are the option names in all-lower-case form, without underscores, and
without the optional no
at the beginning even though the builtins
setopt
and unsetopt
understand option names with upper case letters,
underscores, and the optional no
. The following alters the matching
rules so that the prefix no
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:
compadd -M 'L:|[nN][oO]= M:_= M:{[:upper:]}={[:lower:]}' - \
${(k)options}
The first part says that the pattern ‘[nN][oO]
’ 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 (L
and M
) guarantees that
what has already been typed on the command line (in particular the
prefix no
) will not be deleted.
Note that the use of L
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 ‘_NO_f
’ would not be completed to
‘_NO_foo
’, nor would ‘NONO_f
’ be completed to ‘NONO_foo
’ because
of the leading underscore or the second ‘NO
’ on the line which makes
the pattern fail even though they are otherwise ignored. To fix this,
one would use ‘B:[nN][oO]=
’ 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 match-spec
s.
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:
compadd -M 'm:{[:lower:]}={[:upper:]}' ...
This makes lower case letters match their upper case counterparts. To make upper case letters match the lower case forms as well:
compadd -M 'm:{[:lower:][:upper:]}={[:upper:][:lower:]}' ...
A nice example for the use of *
patterns is partial word completion.
Sometimes you would like to make strings like ‘c.s.u
’ complete to
strings like ‘comp.source.unix
’, 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. ‘comp
’, ‘source
’ and ‘unix
’ 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:
compadd -M 'r:|.=* r:|=*' \
- comp.sources.unix comp.sources.misc ...
The first specification says that lpat
is the empty string, while
anchor
is a dot; tpat
is *
, so this can match anything except for
the ‘.
’ from the anchor in the trial completion word. So in ‘c.s.u
’,
the matcher sees ‘c
’, followed by the empty string, followed by the
anchor ‘.
’, and likewise for the second dot, and replaces the empty
strings before the anchors, giving
‘c
[omp
].s
[ources
].u
[nix
]’, where the last part of
the completion is just as normal.
With the pattern shown above, the string ‘c.u
’ could not be completed
to ‘comp.sources.unix
’ because the single star means that no dot
(matched by the anchor) can be skipped. By using two stars as in
‘r:|.=**
’, however, ‘c.u
’ could be completed to
‘comp.sources.unix
’. 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.
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
COMPLETE_IN_WORD
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 ‘nix
’ 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.
More generally, the specification
compadd -M 'r:|[.,_-]=* r:|=*' ...
allows one to complete words with abbreviations before any of the
characters in the square brackets. For example, to complete
veryverylongfile.c
rather than veryverylongheader.h
with the above
in effect, you can just type very.c
before attempting completion.
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 ‘LikeThis
’ (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:
compadd -M 'r:|[[:upper:]0-9]=* r:|=*' LikeTHIS FooHoo 5foo123 5bar234
But with this, the string ‘H
’ would neither complete to ‘FooHoo
’ nor
to ‘LikeTHIS
’ because in each case there is an upper case letter
before the ‘H
’ and that is matched by the anchor. Likewise, a ‘2
’
would not be completed. In both cases this could be changed by using
‘r:|[[:upper:]0-9]=**
’, but then ‘H
’ completes to both
‘LikeTHIS
’ and ‘FooHoo
’ and a ‘2
’ matches the other strings
because characters can be inserted before every upper case letter and
digit. To avoid this one would use:
compadd -M 'r:[^[:upper:]0-9]||[[:upper:]0-9]=** r:|=*' \
LikeTHIS FooHoo foo123 bar234
By using these two anchors, a ‘H
’ matches only upper case ‘H
’s that
are immediately preceded by something matching the left anchor
‘[^[:upper:]0-9]
’. The effect is, of course, that ‘H
’ matches only
the string ‘FooHoo
’, a ‘2
’ matches only ‘bar234
’ and so on.
When using the completion system (see Completion
System), users can define
match specifications that are to be used for specific contexts by using
the matcher
and matcher-list
styles. The values for the latter will
be used everywhere.
19.6 Completion Widget Example
The first step is to define the widget:
zle -C complete complete-word complete-files
Then the widget can be bound to a key using the bindkey
builtin
command:
bindkey '^X\t' complete
After that the shell function complete-files
will be invoked after
typing control-X and TAB. The function should then generate the matches,
e.g.:
complete-files () { compadd - * }
This function will complete files in the current directory matching the current word.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 20 Completion System
20 Completion System
20.1 Description
This describes the shell code for the ‘new’ completion system, referred
to as compsys
. It is written in shell functions based on the features
described in the previous chapter, Completion
Widgets.
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 Initialization.
The context that decides what completion is to be performed may be
- 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’;
- a special context, denoting an element in the shell’s syntax. For example ‘a word in command position’ or ‘an array subscript’.
A full context specification contains other elements, as we shall describe.
Besides commands names and contexts, the system employs two more concepts, styles and tags. These provide ways for the user to configure the system’s behaviour.
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 ls
command the user may prefer to try files
before directories
, so both
of these are tags. They also appear as the rightmost element in a
context specification.
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 zstyle
command described in The zsh/zutil
Module.
In summary, tags describe what the completion objects are, and style
how
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 Completion System Configuration.
When a completion is requested, a dispatcher function is called; see the
description of _main_complete
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
completers, functions that implement individual completion strategies:
simple completion, error correction, completion with error correction,
menu selection, etc.
More generally, the shell functions contained in the completion system are of two types:
- those beginning ‘
comp
’ are to be called directly; there are only a few of these; - those beginning ‘
_
’ 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.
20.2 Initialization
If the system was installed completely, it should be enough to call the
shell function compinit
from your initialization file; see the next
section. However, the function compinstall
can be run by a user to
configure various aspects of the completion system.
Usually, compinstall
will insert code into .zshrc
, although if
file’s location. Note that it is up to you to make sure that the lines
added to .zshrc
are actually run; you may, for example, need to move
them to an earlier place in the file if .zshrc
usually returns early.
So long as you keep them all together (including the comment lines at
the start and finish), you can rerun compinstall
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 compinstall
,
although lines using the command ‘zstyle
’ should be gracefully
handled.
The new code will take effect next time you start the shell, or run
.zshrc
by hand; there is also an option to make them take effect
immediately. However, if compinstall
has removed definitions, you will
need to restart the shell to see the changes.
To run compinstall
you will need to make sure it is in a directory
mentioned in your fpath
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 fpath
. Then it must be autoloaded
(‘autoload -U compinstall
’ is recommended). You can abort the
installation any time you are being prompted for information, and your
.zshrc
will not be altered at all; changes only take place right at
the end, where you are specifically asked for confirmation.
20.2.1 Use of compinit
This section describes the use of compinit
to initialize completion
for the current session when called directly; if you have run
compinstall
it will be called automatically from your .zshrc
.
To initialize the system, the function compinit
should be in a
directory mentioned in the fpath
parameter, and should be autoloaded
(‘autoload -U compinit
’ is recommended), and then run simply as
‘compinit
’. 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 menu-select
widget, which is part of the zsh/complist
module, you should make sure that that module is loaded before the call
to compinit
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 expand-or-complete
, compinit
will rebind it to complete-word
; this is necessary to use the correct
form of expansion.
Should you need to use the original completion commands, you can still
bind keys to the old widgets by putting a ‘.
’ in front of the widget
name, e.g. ‘.expand-or-complete
’.
To speed up the running of compinit
, 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 compinit
with the option
-D
. The dumped file is .zcompdump
in the same directory as the
startup files (i.e. $ZDOTDIR
or $HOME
); alternatively, an explicit
file name can be given by ‘compinit -d
dumpfile
’. The next
invocation of compinit
will read the dumped file instead of performing
a full initialization.
If the number of completion files changes, compinit
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 #compdef
function (as described
below) change, it is easiest to delete the dump file by hand so that
compinit
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 -C
. In this case the dump file will only be created if there
isn’t one already.
The dumping is actually done by another function, compdump
, but you
will only need to run this yourself if you change the configuration
(e.g. using compdef
) and then want to dump the new one. The name of
the old dumped file will be remembered for this purpose.
If the parameter _compdir
is set, compinit
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.
For security reasons compinit
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,
compinit
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 -u
, and to make compinit
silently ignore all insecure
files and directories use the option -i
. This security check is
skipped entirely when the -C
option is given.
The security check can be retried at any time by running the function
compaudit
. This is the same check used by compinit
, but when it is
executed directly any changes to fpath
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, compaudit
uses fpath
and _compdir
to
find completion system directories, adding missing ones to fpath
as
necessary. To force a check of exactly the directories currently named
in fpath
, set _compdir
to an empty string before calling compaudit
or compinit
.
The function bashcompinit
provides compatibility with bash’s
programmable completion system. When run it will define the functions,
compgen
and complete
which correspond to the bash builtins with the
same names. It will then be possible to use completion specifications
and functions written for bash.
20.2.2 Autoloaded files
The convention for autoloaded functions used in completion is that they
start with an underscore; as already mentioned, the fpath/FPATH
parameter must contain the directory in which they are stored. If zsh
was properly installed on your system, then fpath/FPATH
automatically
contains the required directories for the standard functions.
For incomplete installations, if compinit
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 _compdir
to the search
path. If that directory has a subdirectory named Base
, all
subdirectories will be added to the path. Furthermore, if the
subdirectory Base
has a subdirectory named Core
, compinit
will add
all subdirectories of the subdirectories to the path: this allows the
functions to be in the same format as in the zsh
source distribution.
When compinit
is run, it searches all such files accessible via
fpath/FPATH
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.
The tags are:
-
#compdef
name
... [-
{p
|P
}pattern
... [-N
name
... ] ]
The file will be made autoloadable and the function defined in it will be called when completingname
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-``context``-
described below.Each
name
may also be of the form ‘cmd``=``service
’. When completing the commandcmd
, the function typically behaves as if the command (or special context)service
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$service
when calling the function; the function may choose to interpret this how it wishes, and simpler functions will probably ignore it.If the
#compdef
line contains one of the options-p
or-P
, 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-p
and-P
are used to specify patterns to be tried before or after other completions respectively. Hence-P
may be used to specify default actions.The option
-N
is used after a list following-p
or-P
; it specifies that remaining words no longer define patterns. It is possible to toggle between the three options as many times as necessary. -
#compdef -k
style key-sequence
...
This option creates a widget behaving like the builtin widgetstyle
and binds it to the givenkey-sequence
s, if any. Thestyle
must be one of the builtin widgets that perform completion, namelycomplete-word
,delete-char-or-list
,expand-or-complete
,expand-or-complete-prefix
,list-choices
,menu-complete
,menu-expand-or-complete
, orreverse-menu-complete
. If thezsh/complist
module is loaded (see The zsh/complist Module) the widgetmenu-select
is also available.When one of the
key-sequence
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 thanundefined-key
). The widget created has the same name as the file and can be bound to any other keys usingbindkey
as usual. -
#compdef -K
widget-name
style
key-sequence
[name
style
seq
... ]
This is similar to-k
except that only onekey-sequence
argument may be given for eachwidget-name
style
pair. However, the entire set of three arguments may be repeated with a different set of arguments. Note in particular that thewidget-name
must be distinct in each set. If it does not begin with ‘_
’ this will be added. Thewidget-name
should not clash with the name of any existing widget: names based on the name of the function are most useful. For example,#compdef -K _foo_complete complete-word "^X^C" \ _foo_list list-choices "^X^D"
(all on one line) defines a widget
_foo_complete
for completion, bound to ‘^X^C
’, and a widget_foo_list
for listing, bound to ‘^X^D
’. -
#autoload
[options
]
Functions with the#autoload
tag are marked for autoloading but are not otherwise treated specially. Typically they are to be called from within one of the completion functions. Anyoptions
supplied will be passed to theautoload
builtin; a typical use is+X
to force the function to be loaded immediately. Note that the-U
and-z
flags are always added implicitly.
The #
is part of the tag name and no white space is allowed after it.
The #compdef
tags use the compdef
function described below; the main
difference is that the name of the function is supplied implicitly.
The special contexts for which completion functions can be defined are:
-array-value-
The right hand side of an array-assignment (‘name``=(``...``)
’)
-brace-parameter-
The name of a parameter expansion within braces (‘${``...``}
’)
-assign-parameter-
The name of a parameter in an assignment, i.e. on the left hand side of
an ‘=
’
-command-
A word in command position
-condition-
A word inside a condition (‘[[``...``]]
’)
-default-
Any word for which no other completion is defined
-equal-
A word beginning with an equals sign
-first-
This is tried before any other completion function. The function called
may set the _compskip
parameter to one of various values: all
: no
further completion is attempted; a string containing the substring
patterns
: no pattern completion functions will be called; a string
containing default
: the function for the ‘-default-
’ context will
not be called, but functions defined for commands will be.
-math-
Inside mathematical contexts, such as ‘((``...``))
’
-parameter-
The name of a parameter expansion (‘$``...
’)
-redirect-
The word after a redirection operator.
-subscript-
The contents of a parameter subscript.
-tilde-
After an initial tilde (‘~
’), but before the first slash in the word.
-value-
On the right hand side of an assignment.
Default implementations are supplied for each of these contexts. In most
cases the context -``context``-
is implemented by a corresponding
function _``context
, for example the context ‘-tilde-
’ and the
function ‘_tilde
’).
The contexts -redirect-
and -value-
allow extra context-specific
information. (Internally, this is handled by the functions for each
context calling the function _dispatch
.) The extra information is
added separated by commas.
For the -redirect-
context, the extra information is in the form
‘-redirect-,``op``,``command
’, where op
is the redirection
operator and command
is the name of the command on the line. If there
is no command on the line yet, the command
field will be empty.
For the -value-
context, the form is ‘-value-,``name``,``command
’,
where name
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
‘assoc=(key <TAB>
’, name
is expanded to ‘name``-``key
’. In certain
special contexts, such as completing after ‘make CFLAGS=
’, the
command
part gives the name of the command, here make
; otherwise it
is empty.
It is not necessary to define fully specific completions as the
functions provided will try to generate completions by progressively
replacing the elements with ‘-default-
’. For example, when completing
after ‘foo=<TAB>
’, _value
will try the names ‘-value-,foo,
’ (note
the empty command
part), ‘-value-,foo,-default-
’
and‘-value-,-default-,-default-
’, in that order, until it finds a
function to handle the context.
As an example:
compdef '_files -g "*.log"' '-redirect-,2>,-default-'
completes files matching ‘*.log
’ after ‘2> <TAB>
’ for any command
with no more specific handler defined.
Also:
compdef _foo -value-,-default-,-default-
specifies that _foo
provides completions for the values of parameters
for which no special function has been defined. This is usually handled
by the function _value
itself.
The same lookup rules are used when looking up styles (as described below); for example
zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'
is another way to make completion after ‘2> <TAB>
’ complete files
matching ‘*.log
’.
20.2.3 Functions
The following function is defined by compinit
and may be called
directly.
-
compdef
[-ane
]function name
... [-
{p
|P
}pattern
... [-N
name
...]]
compdef -d
name
...
compdef -k
[-an
]function style key-sequence
[key-sequence
... ]
compdef -K
[-an
]function name style key-seq
[name style seq
... ]
The first form defines thefunction
to call for completion in the given contexts as described for the#compdef
tag above.Alternatively, all the arguments may have the form ‘
cmd``=``service
’. Hereservice
should already have been defined by ‘cmd1``=``service
’ lines in#compdef
files, as described above. The argument forcmd
will be completed in the same way asservice
.The
function
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-e
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 theeval
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 ‘.h
’ as arguments to the commandfoo
:compdef '_files -g "*.h"' foo
The option
-n
prevents any completions already defined for the command or context from being overwritten.The option
-d
deletes any completion defined for the command or contexts listed.The
name
s may also contain-p
,-P
and-N
options as described for the#compdef
tag. The effect on the argument list is identical, switching between definitions of patterns tried initially, patterns tried finally, and normal commands and contexts.The parameter
$_compskip
may be set by any function defined for a pattern context. If it is set to a value containing the substring ‘patterns
’ none of the pattern-functions will be called; if it is set to a value containing the substring ‘all
’, no other function will be called. Setting$_compskip
in this manner is of particular utility when using the-p
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.The form with
-k
defines a widget with the same name as thefunction
that will be called for each of thekey-sequence
s; this is like the#compdef -k
tag. The function should generate the completions needed and will otherwise behave like the builtin widget whose name is given as thestyle
argument. The widgets usable for this are:complete-word
,delete-char-or-list
,expand-or-complete
,expand-or-complete-prefix
,list-choices
,menu-complete
,menu-expand-or-complete
, andreverse-menu-complete
, as well asmenu-select
if thezsh/complist
module is loaded. The option-n
prevents the key being bound if it is already to bound to something other thanundefined-key
.The form with
-K
is similar and defines multiple widgets based on the samefunction
, each of which requires the set of three argumentsname
,style
andkey-seq
uence, where the latter two are as for-k
and the first must be a unique widget name beginning with an underscore.Wherever applicable, the
-a
option makes thefunction
autoloadable, equivalent toautoload -U ``function
.
The function compdef
can be used to associate existing completion
functions with new commands. For example,
compdef _pids foo
uses the function _pids
to complete process IDs for the command foo
.
Note also the _gnu_generic
function described below, which can be used
to complete options for commands that understand the ‘-``-help
’
option.
20.3 Completion System Configuration
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.
20.3.1 Overview
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 ‘grep
’ or
‘zsh
’) and options to which the current word may be an argument
(such as the ‘-o
’ option to zsh
which takes a shell option as an
argument).
The context starts out very generic ("we are beginning a completion") and becomes more specific as more is learned ("the current word is in a position that is usually a command name" or "the current word might be a variable name" and so on). Therefore the context will vary during the same call to the completion system.
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 style pattern, which is matched against a context when needed to look up context-sensitive options that configure the completion system.
The next few paragraphs explain how a context is composed within the
completion function suite. Following that is discussion of how styles
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 zstyle
builtin command (The zsh/zutil
Module).
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
:completion:``function``:``completer``:``command``:``argument``:``tag
.
These have the following meaning:
- The literal string
completion
, 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. - The
function
, 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 aspredict-on
and the various functions in theWidget
directory of the distribution to the name of that function, often in an abbreviated form. - The
completer
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; ‘complete
’ is the simplest, but other completers exist to perform related tasks such as correction, or to modify the behaviour of a later completer. See Control Functions for more information. - The
command
or a special-``context``-
, just at it appears following the#compdef
tag or thecompdef
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 thecvs
command sets this field tocvs-add
when completing arguments to theadd
subcommand. - The
argument
; this indicates which command line or option argument we are completing. For command arguments this generally takes the formargument-``n
, wheren
is the number of the argument, and for arguments to options the formoption-``opt``-``n
wheren
is the number of the argument to optionopt
. 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. - The
tag
. 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.
The context is gradually put together as the functions are executed,
starting with the main entry point, which adds :completion:
and the
function
element if necessary. The completer then adds the completer
element. The contextual completion adds the command
and argument
options. Finally, the tag
is added when the types of completion are
known. For example, the context name
:completion::complete:dvips:option-o-1:files
says that normal completion was attempted as the first argument to the
option -o
of the command dvips
:
dvips -o ...
and the completion function will generate filenames.
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
tag-order
style. Completion is then restricted to the list of given
tags in the given order.
The _complete_help
bindable command shows all the contexts and tags
available for completion at a particular point. This provides an easy
way of finding information for tag-order
and other styles. It is
described in Bindable Commands.
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.
For example, many completion functions can generate matches in a simple
and a verbose form and use the verbose
style to decide which form
should be used. To make all such functions use the verbose form, put
zstyle ':completion:*' verbose yes
in a startup file (probably .zshrc
). This gives the verbose
style
the value yes
in every context inside the completion system, unless
that context has a more specific definition. It is best to avoid giving
the context as ‘*
’ in case the style has some meaning outside the
completion system.
Many such general purpose styles can be configured simply by using the
compinstall
function.
A more specific example of the use of the verbose
style is by the
completion for the kill
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:
zstyle ':completion:*:*:kill:*:*' verbose no
For even more control, the style can use one of the tags ‘jobs
’ or
‘processes
’. To turn off verbose display only for jobs:
zstyle ':completion:*:*:kill:*:jobs' verbose no
The -e
option to zstyle
even allows completion function code to
appear as the argument to a style; this requires some understanding of
the internals of completion functions (see Completion
Widgets)). For example,
zstyle -e ':completion:*' hosts 'reply=($myhosts)'
This forces the value of the hosts
style to be read from the variable
myhosts
each time a host name is needed; this is useful if the value
of myhosts
can change dynamically. For another useful example, see the
example in the description of the file-list
style below. This form can
be slow and should be avoided for commonly examined styles such as
menu
and list-rows-first
.
Note that the order in which styles are defined 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, ‘:completion::complete:::foo
’ is
more specific than ‘:completion::complete:::*’
), and longer patterns
are preferred over shorter patterns.
A good rule of thumb is that any completion style pattern that needs to
include more than one wildcard (*
) and that does not end in a tag
name, should include all six colons (:
), possibly surrounding
additional wildcards.
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.
20.3.2 Standard Tags
Some of the following are only used when looking up particular styles and do not refer to a type of match.
accounts
used to look up the users-hosts
style
all-expansions
used by the _expand
completer when adding the single string containing
all possible expansions
all-files
for the names of all files (as distinct from a particular subset, see
the globbed-files
tag).
arguments
for arguments to a command
arrays
for names of array parameters
association-keys
for keys of associative arrays; used when completing inside a subscript to a parameter of this type
bookmarks
when completing bookmarks (e.g. for URLs and the zftp
function suite)
builtins
for names of builtin commands
characters
for single characters in arguments of commands such as stty
. Also used
when completing character classes after an opening bracket
colormapids
for X colormap ids
colors
for color names
commands
for names of external commands. Also used by complex commands such as
cvs
when completing names subcommands.
contexts
for contexts in arguments to the zstyle
builtin command
corrections
used by the _approximate
and _correct
completers for possible
corrections
cursors
for cursor names used by X programs
default
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
function
field of the context name is set
descriptions
used when looking up the value of the format
style to generate
descriptions for types of matches
devices
for names of device special files
directories
for names of directories — local-directories
is used instead when
completing arguments of cd
and related builtin commands when the
cdpath
array is set
directory-stack
for entries in the directory stack
displays
for X display names
domains
for network domains
email-``plugin
for email addresses from the ‘_email-``plugin
’ backend of
_email_addresses
expansions
used by the _expand
completer for individual words (as opposed to the
complete set of expansions) resulting from the expansion of a word on
the command line
extensions
for X server extensions
file-descriptors
for numbers of open file descriptors
files
the generic file-matching tag used by functions completing filenames
fonts
for X font names
fstypes
for file system types (e.g. for the mount
command)
functions
names of functions — normally shell functions, although certain commands may understand other kinds of function
globbed-files
for filenames when the name has been generated by pattern matching
groups
for names of user groups
history-words
for words from the history
hosts
for hostnames
indexes
for array indexes
jobs
for jobs (as listed by the ‘jobs
’ builtin)
interfaces
for network interfaces
keymaps
for names of zsh keymaps
keysyms
for names of X keysyms
libraries
for names of system libraries
limits
for system limits
local-directories
for names of directories that are subdirectories of the current working
directory when completing arguments of cd
and related builtin commands
(compare path-directories
) — when the cdpath
array is unset,
directories
is used instead
manuals
for names of manual pages
mailboxes
for e-mail folders
maps
for map names (e.g. NIS maps)
messages
used to look up the format
style for messages
modifiers
for names of X modifiers
modules
for modules (e.g. zsh
modules)
my-accounts
used to look up the users-hosts
style
named-directories
for named directories (you wouldn’t have guessed that, would you?)
names
for all kinds of names
newsgroups
for USENET groups
nicknames
for nicknames of NIS maps
options
for command options
original
used by the _approximate
, _correct
and _expand
completers when
offering the original string as a match
other-accounts
used to look up the users-hosts
style
other-files
for the names of any non-directory files. This is used instead of
all-files
when the list-dirs-first
style is in effect.
packages
for packages (e.g. rpm
or installed Debian
packages)
parameters
for names of parameters
path-directories
for names of directories found by searching the cdpath
array when
completing arguments of cd
and related builtin commands (compare
local-directories
)
paths
used to look up the values of the expand
, ambiguous
and
special-dirs
styles
pods
for perl pods (documentation files)
ports
for communication ports
prefixes
for prefixes (like those of a URL)
printers
for print queue names
processes
for process identifiers
processes-names
used to look up the command
style when generating the names of
processes for killall
sequences
for sequences (e.g. mh
sequences)
sessions
for sessions in the zftp
function suite
signals
for signal names
strings
for strings (e.g. the replacement strings for the cd
builtin command)
styles
for styles used by the zstyle builtin command
suffixes
for filename extensions
tags
for tags (e.g. rpm
tags)
targets
for makefile targets
time-zones
for time zones (e.g. when setting the TZ
parameter)
types
for types of whatever (e.g. address types for the xhost
command)
urls
used to look up the urls
and local
styles when completing URLs
users
for usernames
values
for one of a set of values in certain lists
variant
used by _pick_variant
to look up the command to run when determining
what program is installed for a particular command name.
visuals
for X visuals
warnings
used to look up the format
style for warnings
widgets
for zsh widget names
windows
for IDs of X windows
zsh-options
for shell options
20.3.3 Standard Styles
Note that the values of several of these styles represent boolean
values. Any of the strings ‘true
’, ‘on
’, ‘yes
’, and ‘1
’ can be
used for the value ‘true’ and any of the strings ‘false
’, ‘off
’,
‘no
’, and ‘0
’ 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.
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
list-colors
and styles controlling completion listing such as
list-packed
and last-prompt
. When tested for the default
tag, only
the function
field of the context will be set so that a style using
the default
tag will normally be defined along the lines of:
zstyle ':completion:*:default' menu ...
accept-exact
This is tested for the default
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).
When completing pathnames (where the tag used is ‘paths
’) 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.
This style is also used by the _expand
completer to decide if words
beginning with a tilde or parameter expansion should be expanded. For
example, if there are parameters foo
and foobar
, the string ‘$foo
’
will only be expanded if accept-exact
is set to ‘true’; otherwise the
completion system will be allowed to complete $foo
to $foobar
. If
the style is set to ‘continue
’, _expand
will add the expansion as a
match and the completion system will also be allowed to continue.
accept-exact-dirs
This is used by filename completion. Unlike accept-exact
it is a
boolean. By default, filename completion examines all components of a
path to see if there are completions of that component, even if the
component matches an existing directory. For example, when completion
after /usr/bin/
, the function examines possible completions to /usr
.
When this style is ‘true’, any prefix of a path that matches an existing
directory is accepted without any attempt to complete it further. Hence,
in the given example, the path /usr/bin/
is accepted immediately and
completion tried in that directory.
This style is also useful when completing after directories that
magically appear when referenced, such as ZFS .zfs
directories or
NetApp .snapshot
directories. When the style is set the shell does not
check for the existence of the directory within the parent directory.
If you wish to inhibit this behaviour entirely, set the
path-completion
style (see below) to ‘false’.
add-space
This style is used by the _expand
completer. If it is ‘true’ (the
default), a space will be inserted after all words resulting from the
expansion, or a slash in the case of directory names. If the value is
‘file
’, the completer will only add a space to names of existing
files. Either a boolean ‘true’ or the value ‘file
’ may be combined
with ‘subst
’, in which case the completer will not add a space to
words generated from the expansion of a substitution of the form
‘$(``...``)
’ or ‘${``...``}
’.
The _prefix
completer uses this style as a simple boolean value to
decide if a space should be inserted before the suffix.
ambiguous
This applies when completing non-final components of filename paths, in
other words those with a trailing slash. If it is set, the cursor is
left after the first ambiguous component, even if menu completion is in
use. The style is always tested with the paths
tag.
assign-list
When completing after an equals sign that is being treated as an
assignment, the completion system normally completes only one filename.
In some cases the value may be a list of filenames separated by colons,
as with PATH
and similar parameters. This style can be set to a list
of patterns matching the names of such parameters.
The default is to complete lists when the word on the line already contains a colon.
auto-description
If set, this style’s value will be used as the description for options
that are not described by the completion functions, but that have
exactly one argument. The sequence ‘%d
’ in the value will be replaced
by the description for this argument. Depending on personal preferences,
it may be useful to set this style to something like ‘specify: %d
’.
Note that this may not work for some commands.
avoid-completer
This is used by the _all_matches
completer to decide if the string
consisting of all matches should be added to the list currently being
generated. Its value is a list of names of completers. If any of these
is the name of the completer that generated the matches in this
completion, the string will not be added.
The default value for this style is ‘_expand _old_list _correct _approximate
’, i.e. it contains the completers for which a string with
all matches will almost never be wanted.
cache-path
This style defines the path where any cache files containing dumped
completion data are stored. It defaults to ‘$ZDOTDIR/.zcompcache
’, or
‘$HOME/.zcompcache
’ if $ZDOTDIR
is not defined. The completion
cache will not be used unless the use-cache
style is set.
cache-policy
This style defines the function that will be used to determine whether a
cache needs rebuilding. See the section on the _cache_invalid
function
below.
call-command
This style is used in the function for commands such as make
and ant
where calling the command directly to generate matches suffers problems
such as being slow or, as in the case of make
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’.
command
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 ‘builtin
’ or ‘command
’ 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.
As an example, the completion function for process IDs uses this style
with the processes
tag to generate the IDs to complete and the list of
processes to display (if the verbose
style is ‘true’). The list
produced by the command should look like the output of the ps
command.
The first line is not displayed, but is searched for the string ‘PID
’
(or ‘pid
’) to find the position of the process IDs in the following
lines. If the line does not contain ‘PID
’, the first numbers in each
of the other lines are taken as the process IDs to complete.
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.
command-path
This is a list of directories to search for commands to complete. The
default for this style is the value of the special parameter path
.
commands
This is used by the function completing sub-commands for the system
initialisation scripts (residing in /etc/init.d
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
‘start
’ and ‘stop
’.
complete
This is used by the _expand_alias
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.
complete-options
This is used by the completer for cd
, chdir
and pushd
. For these
commands a -
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 -
. If it is ‘true’, options will be completed
after an initial -
unless there is a preceding -``-
on the command
line.
completer
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 Control Functions.
Each string may be either the name of a completer function or a string
of the form ‘function``:``name
’. In the first case the completer
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 function
is the name of the completer to call,
but the context will contain the user-defined name
in the completer
field of the context. If the name
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 name
appended to it. For example:
zstyle ':completion:*' completer _complete _complete:-foo
Here, completion will call the _complete
completer twice, once using
‘complete
’ and once using ‘complete-foo
’ in the completer
field
of the context. Normally, using the same completer more than once only
makes sense when used with the ‘functions``:``name
’ form, because
otherwise the context name will be the same in all calls to the
completer; possible exceptions to this rule are the _ignored
and
_prefix
completers.
The default value for this style is ‘_complete _ignored
’: only
completion will be done, first using the ignored-patterns
style and
the $fignore
array and then without ignoring matches.
condition
This style is used by the _list
completer function to decide if
insertion of matches should be delayed unconditionally. The default is
‘true’.
delimiters
This style is used when adding a delimiter for use with history
modifiers or glob qualifiers that have delimited arguments. It is an
array of preferred delimiters to add. Non-special characters are
preferred as the completion system may otherwise become confused. The
default list is :
, +
, /
, -
, %
. The list may be empty to force
a delimiter to be typed.
disabled
If this is set to ‘true’, the _expand_alias
completer and bindable
command will try to expand disabled aliases, too. The default is
‘false’.
domains
A list of names of network domains for completion. If this is not set,
domain names will be taken from the file /etc/resolv.conf
.
environ
The environ style is used when completing for ‘sudo
’. It is set to an
array of ‘VAR``=``value
’ assignments to be exported into the local
environment before the completion for the target command is invoked.
zstyle ':completion:*:sudo::' environ \
PATH="/sbin:/usr/sbin:$PATH" HOME="/root"
expand
This style is used when completing strings consisting of multiple parts, such as path names.
If one of its values is the string ‘prefix
’, the partially typed word
from the line will be expanded as far as possible even if trailing parts
cannot be completed.
If one of its values is the string ‘suffix
’, 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.
fake
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 ‘value``:``description
’; the colon and
description may be omitted, but any literal colons in value
must be
quoted with a backslash. Any description
provided is shown alongside
the value in completion listings.
It is important to use a sufficiently restrictive context when
specifying fake strings. Note that the styles fake-files
and
fake-parameters
provide additional features when completing files or
parameters.
fake-always
This works identically to the fake
style except that the
ignored-patterns
style is not applied to it. This makes it possible to
override a set of matches completely by setting the ignored patterns to
‘*
’.
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 tag-order
style to divide the
named-directories
tag into two when performing completion with the
standard completer complete
for arguments of cd
. The tag
named-directories-normal
behaves as normal, but the tag
named-directories-mine
contains a fixed set of directories. This has
the effect of adding the match group ‘extra directories
’ with the
given completions.
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 '*'
fake-files
This style is used when completing files and looked up without a tag.
Its values are of the form ‘dir``:``names...
’. This will add the
names
(strings separated by spaces) as possible matches when
completing in the directory dir
, even if no such files really exist.
The dir may be a pattern; pattern characters or colons in dir
should
be quoted with a backslash to be treated literally.
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 accept-exact-dirs
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.
The pattern form can be used to add a certain ‘magic’ entry to all directories on a particular file system.
fake-parameters
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 ‘scalar
’, ‘array
’
or ‘integer
’). 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.
file-list
This style controls whether files completed using the standard builtin
mechanism are to be listed with a long list similar to ls -l
. Note
that this feature uses the shell module zsh/stat
for file information;
this loads the builtin stat
this the following code can be included in
an initialization file:
zmodload -i zsh/stat
disable stat
The style may either be set to a ‘true’ value (or ‘all
’), or one of
the values ‘insert
’ or ‘list
’, 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.
More generally, the value may be an array of any of the above values,
optionally followed by =``num
. If num
is present it gives the
maximum number of matches for which long listing style will be used. For
example,
zstyle ':completion:*' file-list list=20 insert=10
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.
zstyle -e ':completion:*' file-list \
'(( ${+NUMERIC} )) && reply=(true)'
specifies that long format will be used any time a numeric argument is supplied, else short format.
file-patterns
This is used by the standard function for completing filenames,
_files
. If the style is unset up to three tags are offered,
‘globbed-files
’,‘directories
’ and ‘all-files
’, depending on the
types of files expected by the caller of _files
. The first two
(‘globbed-files
’ and ‘directories
’) are normally offered together
to make it easier to complete files in sub-directories.
The file-patterns
style provides alternatives to the default tags,
which are not used. Its value consists of elements of the form
‘pattern``:``tag
’; each string may contain any number of such
specifications separated by spaces.
The pattern
is a pattern that is to be used to generate filenames. Any
occurrence of the sequence ‘%p
’ is replaced by any pattern(s) passed
by the function calling _files
. Colons in the pattern must be preceded
by a backslash to make them distinguishable from the colon before the
tag
. If more than one pattern is needed, the patterns can be given
inside braces, separated by commas.
The tag
s of all strings in the value will be offered by _files
and
used when looking up other styles. Any tag
s in the same word will be
offered at the same time and before later words. If no ‘:``tag
’ is
given the ‘files
’ tag will be used.
The tag
may also be followed by an optional second colon and a
description, which will be used for the ‘%d
’ in the value of the
format
style (if that is set) instead of the default description
supplied by the completion function. If the description given here
contains itself a ‘%d
’, that is replaced with the description supplied
by the completion function.
For example, to make the rm
command first complete only names of
object files and then the names of all files if there is no matching
object file:
zstyle ':completion:*:*:rm:*:*' file-patterns \
'*.o:object-files' '%p:all-files'
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:
zstyle ':completion:*' file-patterns \
'%p:globbed-files' '*(-/):directories' '*:all-files'
This works even where there is no special pattern: _files
matches all
files using the pattern ‘*
’ 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.
During the execution of completion functions, the EXTENDED_GLOB
option
is in effect, so the characters ‘#
’, ‘~
’ and ‘^
’ have special
meanings in the patterns.
file-sort
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:
‘size
’ to sort by the size of the file; ‘links
’ to sort by the
number of links to the file; ‘modification
’ (or ‘time
’ or ‘date
’)
to sort by the last modification time; ‘access
’ to sort by the last
access time; and ‘inode
’ (or ‘change
’) 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
‘reverse
’, sorting is done in the opposite order. If the value
contains the string ‘follow
’, timestamps are associated with the
targets of symbolic links; the default is to use the timestamps of the
links themselves.
file-split-chars
A set of characters that will cause all 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 :
; then everything up to and
including the last :
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.
filter
The ldap
plugin of email address completion (see _email_addresses
)
uses this style to specify the attributes to match against when
filtering entries. So for example, if the style is set to ‘sn
’,
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 command
style to
specify how to connect to your LDAP server.
force-list
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 ‘always
’, 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.
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.
format
If this is set for the descriptions
tag, its value is used as a string
to display above matches in completion lists. The sequence ‘%d
’ 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 compadd -X
(see Completion
Widgets).
The style is tested with each tag valid for the current completion
before it is tested for the descriptions
tag. Hence different format
strings can be defined for different types of match.
Note also that some completer functions define additional
‘%
’-sequences. These are described for the completer functions
that make use of them.
Some completion functions display messages that may be customised by
setting this style for the messages
tag. Here, the ‘%d
’ is replaced
with a message given by the completion function.
Finally, the format string is looked up with the warnings
tag, for use
when no matches could be generated at all. In this case the ‘%d
’ is
replaced with the descriptions for the matches that were expected
separated by spaces. The sequence ‘%D
’ is replaced with the same
descriptions separated by newlines.
It is possible to use printf-style field width specifiers with ‘%d
’
and similar escape sequences. This is handled by the zformat
builtin
command from the zsh/zutil
module, see The zsh/zutil
Module.
glob
This is used by the _expand
completer. If it is set to ‘true’ (the
default), globbing will be attempted on the words resulting from a
previous substitution (see the substitute
style) or else the original
string from the line.
global
If this is set to ‘true’ (the default), the _expand_alias
completer
and bindable command will try to expand global aliases.
group-name
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:
zstyle ':completion:*:*:-command-:*:commands' \
group-name commands
zstyle ':completion:*:*:-command-:*:functions' \
group-name functions
As a consequence, any match with the same tag will be displayed in the same group.
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:
zstyle ':completion:*' group-name ''
All matches for which no group name is defined will be put in a group
named -default-
.
group-order
This style is additional to the group-name
style to specify the order
for display of the groups defined by that style (compare tag-order
,
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.
For example, to have names of builtin commands, shell functions and external commands appear in that order when completing in command position:
zstyle ':completion:*:*:-command-:*:*' group-order \
builtins functions commands
groups
A list of names of UNIX groups. If this is not set, group names are
taken from the YP database or the file ‘/etc/group
’.
hidden
If this is set to ‘true’, matches for the given context will not be
listed, although any description for the matches set with the format
style will be shown. If it is set to ‘all
’, not even the description
will be displayed.
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 tag-order
style can be modified as described below.
hosts
A list of names of hosts that should be completed. If this is not set,
hostnames are taken from the file ‘/etc/hosts
’.
hosts-ports
This style is used by commands that need or accept hostnames and network
ports. The strings in the value should be of the form ‘host``:``port
’.
Valid ports are determined by the presence of hostnames; multiple ports
for the same host may appear.
ignore-line
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 ‘current
’, the
word the cursor is on will not be considered as a possible completion.
The value ‘current-shown
’ is similar but only applies if the list of
completions is currently shown on the screen. Finally, if the style is
set to ‘other
’, all words on the line except for the current one will
be excluded from the possible completions.
The values ‘current
’ and ‘current-shown
’ are a bit like the opposite
of the accept-exact
style: only strings with missing characters will
be completed.
Note that you almost certainly don’t want to set this to ‘true’ or
‘other
’ for a general context such as ‘:completion:*
’. 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.
ignore-parents
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:
-
parent
The name of any directory whose path is already contained in the word on the line is ignored. For example, when completing afterfoo/../
, the directoryfoo
will not be considered a valid completion. -
pwd
The name of the current working directory will not be completed; hence, for example, completion after../
will not use the name of the current directory.
In addition, the value may include one or both of:
-
..
Ignore the specified directories only when the word on the line contains the substring ‘../
’. -
directory
Ignore the specified directories only when names of directories are completed, not when completing names of files.
Excluded values act in a similar fashion to values of the
ignored-patterns
style, so they can be restored to consideration by
the _ignored
completer.
extra-verbose
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’.
ignored-patterns
A list of patterns; any trial completion matching one of the patterns
will be excluded from consideration. The _ignored
completer can appear
in the list of completers to restore the ignored matches. This is a more
configurable version of the shell parameter $fignore
.
Note that the EXTENDED_GLOB
option is set during the execution of
completion functions, so the characters ‘#
’, ‘~
’ and ‘^
’ have
special meanings in the patterns.
insert
This style is used by the _all_matches
completer to decide whether to
insert the list of all matches unconditionally instead of adding the
list as another match.
insert-ids
When completing process IDs, for example as arguments to the kill
and
wait
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 ‘menu
’)
the name will be converted immediately to a set of possible IDs, and
menu completion will be started to cycle through them.
If the value of the style is ‘single
’, 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.
insert-tab
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.
The value may also contain the substrings ‘pending
’ or
‘pending=``val
’. In this case, the typed character will be inserted
instead of starting completion when there is unprocessed input pending.
If a val
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
$PENDING
special parameter from the zsh/zle
module being set
properly which is not guaranteed on all platforms.
The default value of this style is ‘true’ except for completion within
vared
builtin command where it is ‘false’.
insert-unambiguous
This is used by the _match
and _approximate
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.
In the case of the _approximate
completer, the completer field in the
context will already have been set to one of correct-``num
or
approximate-``num
, where num
is the number of errors that were
accepted.
In the case of the _match
completer, the style may also be set to the
string ‘pattern
’. Then the pattern on the line is left unchanged if it
does not match unambiguously.
gain-privileges
If set to true
, this style enables the use of commands like sudo
or
doas
to gain extra privileges when retrieving information for
completion. This is only done when a command such as sudo
appears on
the command-line. To force the use of, e.g. sudo
or to override any
prefix that might be added due to gain-privileges
, the command
style
can be used with a value that begins with a hyphen.
keep-prefix
This style is used by the _expand
completer. If it is ‘true’, the
completer will try to keep a prefix containing a tilde or parameter
expansion. Hence, for example, the string ‘~/f*
’ would be expanded to
‘~/foo
’ instead of ‘/home/user/foo
’. If the style is set to
‘changed
’ (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.
The behaviour of _expand
when this style is ‘true’ is to cause
_expand
to give up when a single expansion with the restored prefix is
the same as the original; hence any remaining completers may be called.
last-prompt
This is a more flexible form of the ALWAYS_LAST_PROMPT
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 default
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
ALWAYS_LAST_PROMPT
option this is independent of the numeric argument.
known-hosts-files
This style should contain a list of files to search for host names and
(if the use-ip
style is set) IP addresses in a format compatible with
ssh known_hosts
files. If it is not set, the files
/etc/ssh/ssh_known_hosts
and ~/.ssh/known_hosts
are used.
list
This style is used by the _history_complete_word
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 AUTO_LIST
. The context
always starts with ‘:completion:history-words
’.
list-colors
If the zsh/complist
module is loaded, this style can be used to set
color specifications. This mechanism replaces the use of the
ZLS_COLORS
and ZLS_COLOURS
parameters described in The zsh/complist
Module, but the syntax is
the same.
If this style is set for the default
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 group-name
style must
be set to an empty string.
In addition to setting styles for specific tags, it is also possible to
use group names specified explicitly by the group-name
tag together
with the ‘(group)
’ syntax allowed by the ZLS_COLORS
and
ZLS_COLOURS
parameters and simply using the default
tag.
It is possible to use any color specifications already set up for the
GNU version of the ls
command:
zstyle ':completion:*:default' list-colors \
${(s.:.)LS_COLORS}
The default colors are the same as for the GNU ls
command and can be
obtained by setting the style to an empty string (i.e. ’’
).
list-dirs-first
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 other-files
is used in place of
all-files
for the remaining files, to indicate that no directories are
presented with that tag.
list-grouped
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 verbose
style is set to ‘true’) will appear as a single entry.
However, menu selection can be used to cycle through all the matches.
list-packed
This is tested for each tag valid in the current context as well as the
default
tag. If it is set to ‘true’, the corresponding matches appear
in listings as if the LIST_PACKED
option were set. If it is set to
‘false’, they are listed normally.
list-prompt
If this style is set for the default
tag, completion lists that don’t
fit on the screen can be scrolled (see The zsh/complist
Module). 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.
The value may contain the escape sequences: ‘%l
’ or ‘%L
’, which will
be replaced by the number of the last line displayed and the total
number of lines; ‘%m
’ or ‘%M
’, the number of the last match shown
and the total number of matches; and ‘%p
’ and ‘%P
’, ‘Top
’ when at
the beginning of the list, ‘Bottom
’ 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 ‘%S
’, ‘%s
’, ‘%B
’, ‘%b
’, ‘%U
’, ‘%u
’ for
entering and leaving the display modes standout, bold and underline, and
‘%F
’, ‘%f
’, ‘%K
’, ‘%k
’ for changing the foreground background
colour, are also available, as is the form ‘%{
...%}
’ for enclosing
escape sequences which display with zero (or, with a numeric argument,
some other) width.
After deleting this prompt the variable LISTPROMPT
should be unset for
the removal to take effect.
list-rows-first
This style is tested in the same way as the list-packed
style and
determines whether matches are to be listed in a rows-first fashion as
if the LIST_ROWS_FIRST
option were set.
list-suffixes
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.
list-separator
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 ‘-``-
’ (two hyphens).
local
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.
For example:
zstyle ':completion:*' local toast \
/var/http/public/toast public_html
Completion after ‘http://toast/stuff/
’ will look for files in the
directory /var/http/public/toast/stuff
, while completion after
‘http://toast/~yousir/
’ will look for files in the directory
~yousir/public_html
.
mail-directory
If set, zsh will assume that mailbox files can be found in the directory
specified. It defaults to ‘~/Mail
’.
match-original
This is used by the _match
completer. If it is set to only
, _match
will try to generate matches without inserting a ‘*
’ at the cursor
position. If set to any other non-empty value, it will first try to
generate matches without inserting the ‘*
’ and if that yields no
matches, it will try again with the ‘*
’ inserted. If it is unset or
set to the empty string, matching will only be performed with the ‘*
’
inserted.
matcher
This style is tested separately for each tag valid in the current
context. Its value is placed before any match specifications given by
the matcher-list
style so can override them via the use of an x:
specification. The value should be in the form described in Completion
Matching Control.
For examples of this, see the description of the tag-order
style.
For notes comparing the use of this and the matcher-list
style, see
under the description of the tag-order
style.
matcher-list
This style can be set to a list of match specifications that are to be applied everywhere. Match specifications are described in Completion Matching Control. 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:
zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'
By default each specification replaces the previous one; however, if a
specification is prefixed with +
, it is added to the existing list.
Hence it is possible to create increasingly general specifications
without repetition:
zstyle ':completion:*' matcher-list \
'' '+m:{a-z}={A-Z}' '+m:{A-Z}={a-z}'
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 _prefix
and _ignored
. For example, to use the
completers _complete
and _prefix
but allow case-insensitive
completion only with _complete
:
zstyle ':completion:*' completer _complete _prefix
zstyle ':completion:*:complete:*:*:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
User-defined names, as explained for the completer
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:
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:|=*'
If the style is unset in any context no match specification is applied.
Note also that some completers such as _correct
and _approximate
do
not use the match specifications at all, though these completers will
only ever be called once even if the matcher-list
contains more than
one element.
Where multiple specifications are useful, note that the entire
completion is done for each element of matcher-list
, 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.
If there is no current matcher or it is empty, and the option
NO_CASE_GLOB
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.
For notes comparing the use of this and the matcher
style, see under
the description of the tag-order
style.
max-errors
This is used by the _approximate
and _correct
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.
If the value for this style contains the string ‘numeric
’, the
completer function will take any numeric argument as the maximum number
of errors allowed. For example, with
zstyle ':completion:*:approximate:::' max-errors 2 numeric
two errors are allowed if no numeric argument is given, but with a
numeric argument of six (as in ‘ESC-6 TAB
’), up to six errors are
accepted. Hence with a value of ‘0 numeric
’, no correcting completion
will be attempted unless a numeric argument is given.
If the value contains the string ‘not-numeric
’, the completer will
not try to generate corrected completions when given a numeric
argument, so in this case the number given should be greater than zero.
For example, ‘2 not-numeric
’ specifies that correcting completion with
two errors will usually be performed, but if a numeric argument is
given, correcting completion will not be performed.
The default value for this style is ‘2 numeric
’.
max-matches-width
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 verbose
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.
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.
menu
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 ‘default
’ tag.
If none of the values found in this way is ‘true’ but at least one is
set to ‘auto
’, the shell behaves as if the AUTO_MENU
option is set.
If one of the values is explicitly set to ‘false’, menu completion will
be explicitly turned off, overriding the MENU_COMPLETE
option and
other settings.
In the form ‘yes=``num
’, where ‘yes
’ may be any of the ‘true’ values
(‘yes
’, ‘true
’, ‘on
’ and ‘1
’), menu completion will be turned on
if there are at least num
matches. In the form ‘yes=long
’, 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 ‘yes=long-list
’ (Typically, the value ‘select=long-list
’
described later is more useful as it provides control over scrolling.)
Similarly, with any of the ‘false’ values (as in ‘no=10
’), menu
completion will not be used if there are num
or more matches.
The value of this widget also controls menu selection, as implemented by
the zsh/complist
module. The following values may appear either
alongside or instead of the values above.
If the value contains the string ‘select
’, menu selection will be
started unconditionally.
In the form ‘select=``num
’, menu selection will only be started if
there are at least num
matches. If the values for more than one tag
provide a number, the smallest number is taken.
Menu selection can be turned off explicitly by defining a value
containing the string‘no-select
’.
It is also possible to start menu selection only if the list of matches
does not fit on the screen by using the value ‘select=long
’. To start
menu selection even if the current widget only performs listing, use the
value ‘select=long-list
’.
To turn on menu completion or menu selection when there are a certain
number of matches or the list of matches does not fit on the screen,
both of ‘yes=
’ and ‘select=
’ may be given twice, once with a number
and once with ‘long
’ or ‘long-list
’.
Finally, it is possible to activate two special modes of menu selection.
The word ‘interactive
’ in the value causes interactive mode to be
entered immediately when menu selection is started; see The
zsh/complist Module for a
description of interactive mode. Including the string ‘search
’ does
the same for incremental search mode. To select backward incremental
search, include the string ‘search-backward
’.
muttrc
If set, gives the location of the mutt configuration file. It defaults
to ‘~/.muttrc
’.
numbers
This is used with the jobs
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 ‘1
’, strings will
only be used if all jobs differ in the first word on their command
lines.
old-list
This is used by the _oldlist
completer. If it is set to ‘always
’,
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 ‘never
’, giving the behaviour without the
_oldlist
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 _oldlist
. 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.
For example, suppose you type ^Xc
to use the _correct_word
widget,
which generates a list of corrections for the word under the cursor.
Usually, typing ^D
would generate a standard list of completions for
the word on the command line, and show that. With _oldlist
, it will
instead show the list of corrections already generated.
As another example consider the _match
completer: with the
insert-unambiguous
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 _oldlist
completer and setting this
style to _match
, the list of matches generated on the first attempt
will be used again.
old-matches
This is used by the _all_matches
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 ‘only
’. If the value is ‘only
’,
_all_matches
will only use an old list and won’t have any effect on
the list of matches currently being generated.
If this style is set it is generally unwise to call the _all_matches
completer unconditionally. One possible use is for either this style or
the completer
style to be defined with the -e
option to zstyle
to
make the style conditional.
old-menu
This is used by the _oldlist
completer. It controls how menu
completion behaves when a completion has already been inserted and the
user types a standard completion key such as TAB
. The default
behaviour of _oldlist
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
_oldlist
completer.
For example, suppose you type ^Xc
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 TAB
at this point would start
trying to complete the line as it now appears. With _oldlist
, it
instead continues to cycle through the list of corrections.
original
This is used by the _approximate
and _correct
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 correct-``num
or approximate-``num
, where num
is the number of errors that were accepted.
packageset
This style is used when completing arguments of the Debian ‘dpkg
’
program. It contains an override for the default package set for a given
context. For example,
zstyle ':completion:*:complete:dpkg:option--status-1:*' \
packageset avail
causes available packages, rather than only installed packages, to be
completed for ‘dpkg -``-status
’.
path
The function that completes color names uses this style with the
colors
tag. The value should be the pathname of a file containing
color names in the format of an X11 rgb.txt
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.
path-completion
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, /u/b/z
can be completed to
/usr/bin/zsh
. Explicitly setting this style to ‘false’ inhibits this
behaviour for path components up to the /
before the cursor; this
overrides the setting of accept-exact-dirs
.
Even with the style set to ‘false’, it is still possible to complete
multiple paths by setting the option COMPLETE_IN_WORD
and moving the
cursor back to the first component in the path to be completed. For
example, /u/b/z
can be completed to /usr/bin/zsh
if the cursor is
after the /u
.
pine-directory
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.
ports
A list of Internet service names (network ports) to complete. If this is
not set, service names are taken from the file ‘/etc/services
’.
prefix-hidden
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.
The default value for this style is ‘false’.
prefix-needed
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.
The style is applicable to the options
, signals
, jobs
,
functions
, and parameters
completion tags.
For command options, this means that the initial ‘-
’, ‘+
’, or
‘-``-
’ must be typed explicitly before option names will be
completed.
For signals, an initial ‘-
’ is required before signal names will be
completed.
For jobs, an initial ‘%
’ is required before job names will be
completed.
For function and parameter names, an initial ‘_
’ or ‘.
’ is required
before function or parameter names starting with those characters will
be completed.
The default value for this style is ‘false’ for function
and
parameter
completions, and ‘true’ otherwise.
preserve-prefix
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 ‘//
’ (double slash) has a special meaning; setting this
style to the string ‘//
’ will preserve it. As another example, setting
this style to ‘?:/
’ under Cygwin would allow completion after
‘a:/...
’ and so on.
range
This is used by the _history
completer and the
_history_complete_word
bindable command to decide which words should
be completed.
If it is a single number, only the last N
words from the history will
be completed.
If it is a range of the form ‘max``:``slice
’, the last slice
words
will be completed; then if that yields no matches, the slice
words
before those will be tried and so on. This process stops either when at
least one match has been found, or max
words have been tried.
The default is to complete all words from the history at once.
recursive-files
If this style is set, its value is an array of patterns to be tested
against ‘$PWD/
’: 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 $PWD/
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 **/*(/)
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
‘*/.git/*
’.
For example,
zstyle ':completion:*' recursive-files '*/zsh/*'
If the current directory is /home/pws/zsh/Src
, then zle_tr
TAB can
be completed to Zle/zle_tricky.c
.
regular
This style is used by the _expand_alias
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 ‘always
’, regular
aliases will be expanded even if not in command position.
rehash
If this is set when completing external commands, the internal list
(hash) of commands will be updated for each search by issuing the
rehash
command. There is a speed penalty for this which is only likely
to be noticeable when directories in the path have slow file access.
remote-access
If set to ‘false’, certain commands will be prevented from making
Internet connections to retrieve remote information. This includes the
completion for the CVS
command.
It is not always possible to know if connections are in fact to a remote site, so some may be prevented unnecessarily.
remove-all-dups
The _history_complete_word
bindable command and the _history
completer use this to decide if all duplicate matches should be removed,
rather than just consecutive duplicates.
select-prompt
If this is set for the default
tag, its value will be displayed during
menu selection (see the menu
style above) when the completion list
does not fit on the screen as a whole. The same escapes as for the
list-prompt
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.
select-scroll
This style is tested for the default
tag and determines how a
completion list is scrolled during a menu selection (see the menu
style above) when the completion list does not fit on the screen as a
whole. If the value is ‘0
’ (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.
separate-sections
This style is used with the manuals
tag when completing names of
manual pages. If it is ‘true’, entries for different sections are added
separately using tag names of the form ‘manual.``X
’, where X
is the
section number. When the group-name
style is also in effect, pages
from different sections will appear separately. This style is also used
similarly with the words
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’.
show-ambiguity
If the zsh/complist
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
list-colors
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.
show-completer
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.
single-ignored
This is used by the _ignored
completer when there is only one match.
If its value is ‘show
’, the single match will be displayed but not
inserted. If the value is ‘menu
’, 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.
sort
This allows the standard ordering of matches to be overridden.
If its value is ‘true
’ or ‘false
’, sorting is enabled or disabled.
Additionally the values associated with the ‘-o
’ option to compadd
can also be listed: match
, nosort
, numeric
, reverse
. If it is
not set for the context, the standard behaviour of the calling widget is
used.
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.
In many cases where a calling widget explicitly selects a particular
ordering in lieu of the default, a value of ‘true
’ 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’.
In the _expand
completer, if it is set to ‘true’, the expansions
generated will always be sorted. If it is set to ‘menu
’, then the
expansions are only sorted when they are offered as single strings but
not in the string containing all possible expansions.
special-dirs
Normally, the completion code will not produce the directory names ‘.
’
and ‘..
’ as possible completions. If this style is set to ‘true’, it
will add both ‘.
’ and ‘..
’ as possible completions; if it is set to
‘..
’, only ‘..
’ will be added.
The following example sets special-dirs
to ‘..
’ when the current
prefix is empty, is a single ‘.
’, or consists only of a path beginning
with ‘../
’. Otherwise the value is ‘false’.
zstyle -e ':completion:*' special-dirs \
'[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'
squeeze-slashes
If set to ‘true’, sequences of slashes in filename paths (for example in
‘foo//bar
’) will be treated as a single slash. This is the usual
behaviour of UNIX paths. However, by default the file completion
function behaves as if there were a ‘*
’ between the slashes.
stop
If set to ‘true’, the _history_complete_word
bindable command will
stop once when reaching the beginning or end of the history. Invoking
_history_complete_word
will then wrap around to the opposite end of
the history. If this style is set to ‘false’ (the default),
_history_complete_word
will loop immediately as in a menu completion.
strip-comments
If set to ‘true’, this style causes non-essential comment text to be
removed from completion matches. Currently it is only used when
completing e-mail addresses where it removes any display name from the
addresses, cutting them down to plain user@host
form.
subst-globs-only
This is used by the _expand
completer. If it is set to ‘true’, the
expansion will only be used if it resulted from globbing; hence, if
expansions resulted from the use of the substitute
style described
below, but these were not further changed by globbing, the expansions
will be rejected.
The default for this style is ‘false’.
substitute
This boolean style controls whether the _expand
completer will first
try to expand all substitutions in the string (such as ‘$(``...``)
’
and ‘${``...``}
’).
The default is ‘true’.
suffix
This is used by the _expand
completer if the word starts with a tilde
or contains a parameter expansion. If it is set to ‘true’, the word will
only be expanded if it doesn’t have a suffix, i.e. if it is something
like ‘~foo
’ or ‘$foo
’ rather than ‘~foo/
’ or ‘$foo/bar
’, unless
that suffix itself contains characters eligible for expansion. The
default for this style is ‘true’.
tag-order
This provides a mechanism for sorting how the tags available in a particular context will be used.
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 file-patterns
style for an exception
to this behavior.)
For example:
zstyle ':completion:*:complete:-command-:*:*' tag-order \
'commands functions'
specifies that completion in command position first offers external commands and shell functions. Remaining tags will be tried if no completions are found.
In addition to tag names, each string in the value may take one of the following forms:
-
-
If any value consists of only a hyphen, then only 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. -
!
tags
...
A string starting with an exclamation mark specifies names of tags that are not to be used. The effect is the same as if all other possible tags for the context had been listed. -
tag``:``label
...
Here,tag
is one of the standard tags andlabel
is an arbitrary name. Matches are generated as normal but the namelabel
is used in contexts instead oftag
. This is not useful in words starting with!
.If the
label
starts with a hyphen, thetag
is prepended to thelabel
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. -
tag``:``label``:``description
As before, butdescription
will replace the ‘%d
’ in the value of theformat
style instead of the default description supplied by the completion function. Spaces in the description must be quoted with a backslash. A ‘%d
’ appearing indescription
is replaced with the description given by the completion function.
In any of the forms above the tag may be a pattern or several patterns
in the form ‘{``pat1``,``pat2...``}
’. In this case all matching tags
will be used except for any given explicitly in the same string.
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:
zstyle ':completion:*:*:-command-:*:*' tag-order \
'functions:-non-comp *' functions
zstyle ':completion:*:functions-non-comp' \
ignored-patterns '_*'
On the first attempt, all tags will be offered but the functions
tag
will be replaced by functions-non-comp
. The ignored-patterns
style
is set for this tag to exclude functions starting with an underscore. If
there are no matches, the second value of the tag-order
style is used
which completes functions using the default tag, this time presumably
including all function names.
The matches for one tag can be split into different groups. For 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 '???*'
With the group-names
style set, options beginning with ‘-``-
’,
options beginning with a single ‘-
’ or ‘+
’ but containing multiple
characters, and single-letter options will be displayed in separate
groups with different descriptions.
Another use of patterns is to try multiple match specifications one
after another. The matcher-list
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 foo
:
zstyle ':completion:*:*:foo:*:*' tag-order '*' '*:-case'
zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'
First, all the tags offered when completing after foo
are tried using
the normal tag name. If that generates no matches, the second value of
tag-order
is used, which tries all tags again except that this time
each has -case
appended to its name for lookup of styles. Hence this
time the value for the matcher
style from the second call to zstyle
in the example is used to make completion case-insensitive.
It is possible to use the -e
option of the zstyle
builtin command to
specify conditions for the use of particular tags. For example:
zstyle -e '*:-command-:*' tag-order '
if [[ -n $PREFIX$SUFFIX ]]; then
reply=( )
else
reply=( - )
fi'
Completion in command position will be attempted only if the string
typed so far is not empty. This is tested using the PREFIX
special
parameter; see Completion
Widgets for a description
of parameters which are special inside completion widgets. Setting
reply
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.
If no tag-order
style has been defined for a context, the strings
‘(|*-)argument-* (|*-)option-* values
’ and ‘options
’ 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.
urls
This is used together with the urls
tag by functions completing URLs.
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.
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).
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 ‘http
’,
‘ftp
’, ‘bookmark
’ and so on. In many cases the next level of
directories will be a filename. The directory hierarchy can descend as
deep as necessary.
For example,
zstyle ':completion:*' urls ~/.urls
mkdir -p ~/.urls/ftp/ftp.zsh.org/pub
allows completion of all the components of the URL ‘netscape
’ or
‘lynx
’. Note, however, that access methods and files are completed
separately, so if the hosts
style is set hosts can be completed
without reference to the urls
style.
See the description in the function _urls
itself for more information
(e.g. ‘more $^fpath/_urls(N)
’).
use-cache
If this is set, the completion caching layer is activated for any
completions which use it (via the _store_cache
, _retrieve_cache
, and
_cache_invalid
functions). The directory containing the cache files
can be changed with the cache-path
style.
use-compctl
If this style is set to a string not equal to false
, 0
, no
, and
off
, the completion system may use any completion specifications
defined with the compctl
builtin command. If the style is unset, this
is done only if the zsh/compctl
module is loaded. The string may also
contain the substring ‘first
’ to use completions defined with
‘compctl -T
’, and the substring ‘default
’ to use the completion
defined with ‘compctl -D
’.
Note that this is only intended to smooth the transition from compctl
to the new completion system and may disappear in the future.
Note also that the definitions from compctl
will only be used if there
is no specific completion function for the command in question. For
example, if there is a function _foo
to complete arguments to the
command foo
, compctl
will never be invoked for foo
. However, the
compctl
version will be tried if foo
only uses default completion.
use-ip
By default, the function _hosts
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
hosts
style is set; note also it must be set before the cache of host
names is generated (typically the first completion attempt).
users
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.
users-hosts
The values of this style should be of the form ‘user``@``host
’ or
‘user``:``host
’. 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.
It is possible to group values for sets of commands which allow a remote
login, such as rlogin
and ssh
, by using the my-accounts
tag.
Similarly, values for sets of commands which usually refer to the
accounts of other people, such as talk
and finger
, can be grouped by
using the other-accounts
tag. More ambivalent commands may use the
accounts
tag.
users-hosts-ports
Like users-hosts
but used for commands like telnet
and containing
strings of the form ‘user``@``host``:``port
’.
verbose
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’.
word
This is used by the _list
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.
20.4 Control Functions
The initialization script compinit
redefines all the widgets which
perform completion to call the supplied widget function
_main_complete
. This function acts as a wrapper calling the so-called
‘completer’ functions that generate matches. If _main_complete
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 completer
style. For
example, to use normal completion and correction if that doesn’t
generate any matches:
zstyle ':completion:*' completer _complete _correct
after calling compinit
. The default value for this style is
‘_complete _ignored
’, i.e. normally only ordinary completion is
tried, first with the effect of the ignored-patterns
style and then
without it. The _main_complete
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
_main_complete
function returns.
If the first argument to _main_complete
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 completer
field of the context and
the other arguments give a command name and arguments to call to
generate the matches.
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 ‘:completion::complete:``...
’.
_all_matches
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
avoid-completer
and old-matches
styles described above.
It may be useful to use the _generic
function described below to bind
_all_matches
to its own keystroke, for 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
Note that this does not generate completions by itself: first use any of
the standard ways of generating a list of completions, then use ^Xa
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:
zstyle ':completion:all-matches::::' completer \
_all_matches _complete
zstyle ':completion:all-matches:*' insert true
In this case the old-matches
style should not be set.
_approximate
This is similar to the basic _complete
completer but allows the
completions to undergo corrections. The maximum number of errors can be
specified by the max-errors
style; see the description of approximate
matching in Filename Generation
for how errors are counted. Normally this completer will only be tried
after the normal _complete
completer:
zstyle ':completion:*' completer _complete _approximate
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.
This completer uses the tags corrections
and original
when
generating the possible corrections and the original string. The
format
style for the former may contain the additional sequences
‘%e
’ and ‘%o
’ which will be replaced by the number of errors
accepted to generate the corrections and the original string,
respectively.
The completer progressively increases the number of errors allowed up to
the limit by the max-errors
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
‘approximate-1
’, on the second try ‘approximate-2
’, and so on.
When _approximate
is called from another function, the number of
errors to accept may be passed with the -a
option. The argument is in
the same format as the max-errors
style, all in one string.
Note that this completer (and the _correct
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 completer
style
using the -e
option to zstyle so that some completers are only used
when completion is attempted a second time on the same string, e.g.:
zstyle -e ':completion:*' completer '
if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
_last_try="$HISTNO$BUFFER$CURSOR"
reply=(_complete _match _prefix)
else
reply=(_ignored _correct _approximate)
fi'
This uses the HISTNO
parameter and the BUFFER
and CURSOR
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 _ignored
, _correct
and _approximate
completers called.
_canonical_paths
[ -A
var
] [ -N
] [ -MJV12nfX
] tag
descr
[ paths
... ]
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 ..
’s are present in the word to be completed; and some paths got
from symlinks).
-A
, if specified, takes the paths from the array variable specified.
Paths can also be specified on the command line as shown above. -N
, if
specified, prevents canonicalizing the paths given before using them for
completion, in case they are already so. The options -M
, -J
, -V
,
-1
, -2
, -n
, -F
, -X
are passed to compadd
.
See _description
for a description of tag
and descr
.
_cmdambivalent
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 /usr/bin/env
) if there are two
or more remaining positional arguments on the command line, and as a
quoted command string (in the manner of system(...)
) otherwise. See
also _cmdstring
and _precommand
.
This function takes no arguments.
_cmdstring
Completes an external command as a single argument, as for
system(...)
.
_complete
This completer generates all possible completions in a context-sensitive
manner, i.e. using the settings defined with the compdef
function
explained above and the current settings of all special parameters. This
gives the normal completion behaviour.
To complete arguments of commands, _complete
uses the utility function
_normal
, which is in turn responsible for finding the particular
function; it is described below. Various contexts of the form
-``context``-
are handled specifically. These are all mentioned above
as possible arguments to the #compdef
tag.
Before trying to find a function for a specific context, _complete
checks if the parameter ‘compcontext
’ is set. Setting ‘compcontext
’
allows the usual completion dispatching to be overridden which is useful
in places such as a function that uses vared
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 ‘values
’ and the description
‘value
’. 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 ‘compcontext
’ is set to a string
containing colons, it should be of the form
‘tag``:``descr``:``action
’. In this case the tag
and descr
give the tag and description to use and the action
indicates what
should be completed in one of the forms accepted by the _arguments
utility function described below.
Finally, if ‘compcontext
’ 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 -command-line-
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.
_correct
Generate corrections, but not completions, for the current word; this is
similar to _approximate
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 _approximate
, but the completer
field in the context name is correct
.
For example, with:
zstyle ':completion:::::' completer \
_complete _correct _approximate
zstyle ':completion:*:correct:::' max-errors 2 not-numeric
zstyle ':completion:*:approximate:::' max-errors 3 numeric
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.
When _correct
is called as a function, the number of errors to accept
may be given following the -a
option. The argument is in the same form
a values to the accept
style, all in one string.
This completer function is intended to be used without the
_approximate
completer or, as in the example, just before it. Using it
after the _approximate
completer is useless since _approximate
will
at least generate the corrected strings generated by the _correct
completer — and probably more.
_expand
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
complete-word
, not expand-or-complete
(the default binding for
TAB
), 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 _complete
completer function.
The tags used when generating expansions are all-expansions
for the
string containing all possible expansions, expansions
when adding the
possible expansions as single matches and original
when adding the
original string from the line. The order in which these strings are
generated, if at all, can be controlled by the group-order
and
tag-order
styles, as usual.
The format string for all-expansions
and for expansions
may contain
the sequence ‘%o
’ which will be replaced by the original string from
the line.
The kind of expansion to be tried is controlled by the substitute
,
glob
and subst-globs-only
styles.
It is also possible to call _expand
as a function, in which case the
different modes may be selected with options: -s
for substitute
,
-g
for glob
and -o
for subst-globs-only
.
_expand_alias
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 regular
, global
and disabled
.
This function is also a bindable command, see Bindable Commands.
_extensions
If the cursor follows the string ‘*.
’, 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
_expand
to expand the pattern. The standard add-space
and
prefix-hidden
styles are observed.
_external_pwds
Completes current directories of other zsh processes belonging to the current user.
This is intended to be used via _generic
, bound to a custom key
combination. Note that pattern matching is enabled so matching is
performed similar to how it works with the _match
completer.
_history
Complete words from the shell’s command history. This completer can be
controlled by the remove-all-dups
, and sort
styles as for the
_history_complete_word
bindable command, see Bindable
Commands and Completion System
Configuration.
_ignored
The ignored-patterns
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
ignored-patterns
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 _prefix
completer. The single-ignored
style is
also available as described above.
_list
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 condition
and word
, see Completion
System Configuration.
_match
This completer is intended to be used after the _complete
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
GLOB_COMPLETE
option.
Normally completion will be performed by taking the pattern from the
line, inserting a ‘*
’ at the cursor position and comparing the
resulting pattern with the possible completions generated. This can be
modified with the match-original
style described above.
The generated matches will be offered in a menu completion unless the
insert-unambiguous
style is set to ‘true’; see the description above
for other options for this style.
Note that matcher specifications defined globally or used by the
completion functions (the styles matcher-list
and matcher
) will not
be used.
_menu
This completer was written as simple example function to show how menu
effect of disabling menu selection which can be useful with _generic
based widgets. It should be used as the first completer in the list.
Note that this is independent of the setting of the MENU_COMPLETE
option and does not work with the other menu completion widgets such as
reverse-menu-complete
, or accept-and-menu-complete
.
_oldlist
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:
old-list
and old-menu
, see Completion System
Configuration.
_precommand
Complete an external command in word-separated arguments, as for exec
and /usr/bin/env
.
_prefix
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 expand-or-complete-prefix
command.
The completer
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
_prefix
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 _prefix
will be called.
For example, consider this global completer
style:
zstyle ':completion:*' completer \
_complete _prefix _correct _prefix:foo
Here, the _prefix
completer tries normal completion but ignoring the
suffix. If that doesn’t generate any matches, and neither does the call
to the _correct
completer after it, _prefix
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 ‘foo
’.
To use _prefix
as the last resort and try only normal completion when
it is invoked:
zstyle ':completion:*' completer _complete ... _prefix
zstyle ':completion::prefix:*' completer _complete
The add-space
style is also respected. If it is set to ‘true’ then
_prefix
will insert a space between the matches generated (if any) and
the suffix.
Note that this completer is only useful if the COMPLETE_IN_WORD
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.
_user_expand
This completer behaves similarly to the _expand
completer but instead
performs expansions defined by users. The styles add-space
and sort
styles specific to the _expand
completer are usable with
_user_expand
in addition to other styles handled more generally by the
completion system. The tag all-expansions
is also available.
The expansion depends on the array style user-expand
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:
-
$``hash
hash
is the name of an associative array. Note this is not a full parameter expression, merely a$
, suitably quoted to prevent immediate expansion, followed by the name of an associative array. If the trial expansion word matches a key inhash
, the resulting expansion is the corresponding value. -
_func
_func
is the name of a shell function whose name must begin with_
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 arrayreply
to a list of expansions. Optionally, it can setREPLY
to a word that will be used as a description for the set of expansions. The return status of the function is irrelevant.
20.5 Bindable Commands
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.
_bash_completions
This function is used by two widgets, _bash_complete-word
and
_bash_list-choices
. It exists to provide compatibility with completion
bindings in bash. The last character of the binding determines what is
completed: ‘!
’, command names; ‘$
’, environment variables; ‘@
’,
host names; ‘/
’, file names; ‘~
’ user names. In bash, the binding
preceded by ‘\e
’ gives completion, and preceded by ‘^X
’ lists
options. As some of these bindings clash with standard zsh bindings,
only ‘\e~
’ and ‘^X~
’ are bound by default. To add the rest, the
following should be added to .zshrc
after compinit
has been run:
for key in '!' '$' '@' '/' '~'; do
bindkey "\e$key" _bash_complete-word
bindkey "^X$key" _bash_list-choices
done
This includes the bindings for ‘~
’ in case they were already bound to
something else; the completion code does not override user bindings.
_correct_filename
(^XC
)
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.
_correct_word
(^Xc
)
Performs correction of the current argument using the usual contextual
completions as possible choices. This stores the string ‘correct-word
’
in the function
field of the context name and then calls the
_correct
completer.
_expand_alias
(^Xa
)
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 regular
, global
and
disabled
.
When used as a bindable command there is one additional feature that can
be selected by setting the complete
style to ‘true’. In this case, if
the word is not the name of an alias, _expand_alias
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 _expand_alias
once
more will expand the now-complete alias name.
_expand_word
(^Xe
)
Performs expansion on the current word: equivalent to the standard
expand-word
command, but using the _expand
completer. Before calling
it, the function
field of the context is set to ‘expand-word
’.
_generic
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 function
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:
zle -C foo complete-word _generic
bindkey '...' foo
zstyle ':completion:foo:*' menu yes select=1
Note in particular that the completer
style may be set for the context
in order to change the set of functions used to generate possible
matches. If _generic
is called with arguments, those are passed
through to _main_complete
as the list of completers in place of those
defined by the completer
style.
_history_complete_word
(\e/
)
Complete words from the shell’s command history. This uses the list
,
remove-all-dups
, sort
, and stop
styles.
_most_recent_file
(^Xm
)
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 N
, complete the N
th most recently modified file. Note the
completion, if any, is always unique.
_next_tags
(^Xn
)
This command alters the set of matches used to that for the next tag, or
set of tags, either as given by the tag-order
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.
_read_comp
(^X^R
)
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 ‘_
’, for example ‘_files -/
’, 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.
Second, any other string will be passed as a set of arguments to
compadd
and should hence be an expression specifying what should be
completed.
A very restricted set of editing commands is available when reading the
string: ‘DEL
’ and ‘^H
’ delete the last character; ‘^U
’ deletes the
line, and ‘^C
’ and ‘^G
’ abort the function, while ‘RET
’ accepts
the completion. Note the string is used verbatim as a command line, so
arguments must be quoted in accordance with standard shell rules.
Once a string has been read, the next call to _read_comp
will use the
existing string instead of reading a new one. To force a new string to
be read, call _read_comp
with a numeric argument.
_complete_debug
(^X?
)
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.
_complete_help
(^Xh
)
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 1
(as in ‘ESC-2 ^Xh
’), then the styles used and the contexts for which they are used
will be shown, too.
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.
_complete_help_generic
Unlike other commands listed here, this must be created as a normal ZLE
widget rather than a completion widget (i.e. with zle -N
). It is used
for generating help with a widget bound to the _generic
widget that is
described above.
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
_generic
widget. That widget will be executed, and information
provided in the same format that the _complete_help
widget displays
for contextual completion.
If the widget’s name contains debug
, for example if it is created as
‘zle -N _complete_debug_generic _complete_help_generic
’, it will
read and execute the keystring for a generic widget as before, but then
generate debugging information as done by _complete_debug
for
contextual completion.
If the widget’s name contains noread
, 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.
The widget works by setting the shell parameter
ZSH_TRACE_GENERIC_WIDGET
which is read by _generic
. Unsetting the
parameter cancels any pending effect of the noread
form.
For example, after executing the following:
zle -N _complete_debug_generic _complete_help_generic
bindkey '^x:' _complete_debug_generic
typing ‘C-x :
’ followed by the key sequence for a generic widget will
cause trace output for that widget to be saved to a file.
_complete_tag
(^Xt
)
This widget completes symbol tags created by the etags
or ctags
programmes (note there is no connection with the completion system’s
tags) stored in a file TAGS
, in the format used by etags
, or tags
,
in the format created by ctags
. It will look back up the path
hierarchy for the first occurrence of either file; if both exist, the
file TAGS
is preferred. You can specify the full path to a TAGS
or
tags
file by setting the parameter $TAGSFILE
or $tagsfile
respectively. The corresponding completion tags used are etags
and
vtags
, after emacs and vi respectively.
20.6 Utility Functions
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 Base
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.
_absolute_command_paths
This function completes external commands as absolute paths (unlike
_command_names -e
which completes their basenames). It takes no
arguments.
_all_labels
[ -x
] [ -12VJ
] tag
name
descr
[ command
arg
... ]
This is a convenient interface to the _next_label
function below,
implementing the loop shown in the _next_label
example. The command
and its arguments are called to generate the matches. The options stored
in the parameter name
will automatically be inserted into the arg
s
passed to the command
. Normally, they are put directly after the
command
, but if one of the arg
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 command
is called.
This allows _all_labels
to be used in almost all cases where the
matches can be generated by a single call to the compadd
builtin
command or by a call to one of the utility functions.
For example:
local expl
...
if _requested foo; then
...
_all_labels foo expl '...' compadd ... - $matches
fi
Will complete the strings from the matches
parameter, using compadd
with additional options which will take precedence over those generated
by _all_labels
.
_alternative
[ -O
name
] [ -C
name
] spec
...
This function is useful in simple cases where multiple tags are
available. Essentially it implements a loop like the one described for
the _tags
function below.
The tags to use and the action to perform if a tag is requested are
described using the spec
s which are of the form:
‘tag``:``descr``:``action
’. The tag
s are offered using _tags
and
if the tag is requested, the action
is executed with the given
description descr
. The action
s are those accepted by the
_arguments
function (described below), excluding the ‘->``state
’ and
‘=``...
’ forms.
For example, the action
may be a simple function call:
_alternative \
'users:user:_users' \
'hosts:host:_hosts'
offers usernames and hostnames as possible matches, generated by the
_users
and _hosts
functions respectively.
Like _arguments
, this function uses _all_labels
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 _alternative
.
The option ‘-O
name
’ is used in the same way as by the _arguments
function. In other words, the elements of the name
array will be
passed to compadd
when executing an action.
Like _tags
this function supports the -C
option to give a different
name for the argument context field.
_arguments
[ -nswWCRS
] [ -A
pat
] [ -O
name
] [
-M
matchspec
]
[ :
] spec
...
_arguments
[ opt
... ] -``-
[ -l
] [ -i
pats
] [
-s
pair
]
[ helpspec
...]
This function can be used to give a complete specification for completion for a command whose arguments follow standard UNIX option and argument conventions.
Options Overview
Options to _arguments
itself must be in separate words, i.e. -s -w
,
not -sw
. The options are followed by spec
s that describe options and
arguments of the analyzed command. To avoid ambiguity, all options to
_arguments
itself may be separated from the spec
forms by a single
colon.
The ‘-``-
’ form is used to intuit spec
forms from the help output of
the command being analyzed, and is described in detail below. The opts
for the ‘-``-
’ form are otherwise the same options as the first form.
Note that ‘-s
’ following ‘-``-
’ has a distinct meaning from ‘-s
’
preceding ‘-``-
’, and both may appear.
The option switches -s
, -S
, -A
, -w
, and -W
affect how
_arguments
parses the analyzed command line’s options. These switches
are useful for commands with standard argument parsing.
The options of _arguments
have the following meanings:
-
-n
With this option,_arguments
sets the parameterNORMARG
to the position of the first normal argument in the$words
array, i.e. the position after the end of the options. If that argument has not been reached,NORMARG
is set to-1
. The caller should declare ‘integer NORMARG
’ if the-n
option is passed; otherwise the parameter is not used. -
-s
Enable option stacking for single-letter options, whereby multiple single-letter options may be combined into a single word. For example, the two options ‘-x
’ and ‘-y
’ may be combined into a single word ‘-xy
’. By default, every word corresponds to a single option name (‘-xy
’ is a single option named ‘xy
’).Options beginning with a single hyphen or plus sign are eligible for stacking; words beginning with two hyphens are not.
Note that
-s
after-``-
has a different meaning, which is documented in the segment entitled ‘Derivingspec
forms from the help output’. -
-w
In combination with-s
, allow option stacking even if one or more of the options take arguments. For example, if-x
takes an argument, with no-s
, ‘-xy
’ is considered as a single (unhandled) option; with-s
,-xy
is an option with the argument ‘y
’; with both-s
and-w
,-xy
is the option-x
and the option-y
with arguments to-x
(and to-y
, if it takes arguments) still to come in subsequent words. -
-W
This option takes-w
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_guard
as part of the action. -
-C
Modify thecurcontext
parameter for an action of the form ‘->``state
’. This is discussed in detail below. -
-R
Return status 300 instead of zero when a$state
is to be handled, in the ‘->``string
’ syntax. -
-S
Do not complete options after a ‘-``-
’ appearing on the line, and ignore the ‘-``-
’. For example, with-S
, in the linefoobar -x -- -y
the ‘
-x
’ is considered an option, the ‘-y
’ is considered an argument, and the ‘-``-
’ is considered to be neither. -
-A
pat
Do not complete options after the first non-option argument on the line.pat
is a pattern matching all strings which are not to be taken as arguments. For example, to make_arguments
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 theoptspec
s, the form is ‘-A "-*"
’. -
-O
name
Pass the elements of the arrayname
as arguments to functions called to executeaction
s. This is discussed in detail below. -
-M
matchspec
Use the match specificationmatchspec
for completing option names and values. The defaultmatchspec
allows partial word completion after ‘_
’ and ‘-
’, such as completing ‘-f-b
’ to ‘-foo-bar
’. The defaultmatchspec
is:r:|[_-]=* r:|=*
spec
s: overview
Each of the following forms is a spec
describing individual sets of
options or arguments on the command line being analyzed.
-
n``:``message``:``action
n``::``message``:``action
This describes then
’th normal argument. Themessage
will be printed above the matches generated and theaction
indicates what can be completed in this position (see below). If there are two colons before themessage
the argument is optional. If themessage
contains only white space, nothing will be printed above the matches unless the action adds an explanation string itself. -
:``message``:``action
::``message``:``action
Similar, but describes the next argument, whatever number that happens to be. If all arguments are specified in this form in the correct order the numbers are unnecessary. -
*:``message``:``action
*::``message``:``action
*:::``message``:``action
This describes how arguments (usually non-option arguments, those not beginning with-
or+
) are to be completed when neither of the first two forms was provided. Any number of arguments can be completed in this fashion.With two colons before the
message
, thewords
special array and theCURRENT
special parameter are modified to refer only to the normal arguments when theaction
is executed or evaluated. With three colons before themessage
they are modified to refer only to the normal arguments covered by this description. -
optspec
optspec``:``...
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.The following forms are available for the initial
optspec
, whether or not the option has arguments.-
*``optspec
Hereoptspec
is one of the remaining forms below. This indicates the followingoptspec
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. -
-``optname
+``optname
In the simplest form theoptspec
is just the option name beginning with a minus or a plus sign, such as ‘-foo
’. The first argument for the option (if any) must follow as a separate word directly after the option.Either of ‘
-+``optname
’ and ‘+-``optname
’ can be used to specify that-``optname
and+``optname
are both valid.In all the remaining forms, the leading ‘
-
’ may be replaced by or paired with ‘+
’ in this way. -
-``optname``-
The first argument of the option must come directly after the option name in the same word. For example, ‘-foo-:``...
’ specifies that the completed option and argument will look like ‘-foo``arg
’. -
-``optname``+
The first argument may appear immediately afteroptname
in the same word, or may appear as a separate word after the option. For example, ‘-foo+:``...
’ specifies that the completed option and argument will look like either ‘-foo``arg
’ or ‘-foo
arg
’. -
-``optname``=
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 ‘-foo=``arg
’ or ‘-foo
arg
’. -
-``optname``=-
The argument to the option must appear after an equals sign in the same word, and may not be given in the next argument. -
optspec``[``explanation``]
An explanation string may be appended to any of the preceding forms ofoptspec
by enclosing it in brackets, as in ‘-q[query operation]
’.The
verbose
style is used to decide whether the explanation strings are displayed with the option in a completion listing.If no bracketed explanation string is given but the
auto-description
style is set and only one argument is described for thisoptspec
, the value of the style is displayed, with any appearance of the sequence ‘%d
’ in it replaced by themessage
of the firstoptarg
that follows theoptspec
; see below.
It is possible for options with a literal ‘
+
’ or ‘=
’ to appear, but that character must be quoted, for example ‘-\+
’.Each
optarg
following anoptspec
must take one of the following forms:-
:``message``:``action
::``message``:``action
An argument to the option;message
andaction
are treated as for ordinary arguments. In the first form, the argument is mandatory, and in the second form it is optional.This group may be repeated for options which take multiple arguments. In other words,
:``message1``:``action1``:``message2``:``action2
specifies that the option takes two arguments. -
:*``pattern``:``message``:``action
:*``pattern``::``message``:``action
:*``pattern``:::``message``:``action
This describes multiple arguments. Only the lastoptarg
for an option taking multiple arguments may be given in this form. If thepattern
is empty (i.e.:*:
), all the remaining words on the line are to be completed as described by theaction
; otherwise, all the words up to and including a word matching thepattern
are to be completed using theaction
.Multiple colons are treated as for the ‘
*:``...
’ forms for ordinary arguments: when themessage
is preceded by two colons, thewords
special array and theCURRENT
special parameter are modified during the execution or evaluation of theaction
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.
-
Any literal colon in an optname
, message
, or action
must be
preceded by a backslash, ‘\:
’.
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, ‘(-two -three 1)-one:``...
’ completes the option
‘-one
’; if this appears on the command line, the options -two
and
-three
and the first ordinary argument will not be completed after it.
‘(-foo):``...
’ specifies an ordinary argument completion; -foo
will
not be completed if that argument is already present.
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 (*
) for the rest arguments
(i.e. a specification of the form ‘*:``...
’); a colon (:
) for all
normal (non-option-) arguments; and a hyphen (-
) for all options. For
example, if ‘(*)
’ appears before an option and the option appears on
the command line, the list of remaining arguments completed.
To aid in reuse of specifications, it is possible to precede any of the
forms above with ‘!
’; 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 _arguments
is called repeatedly for more
specific contexts: on the first call ‘_arguments $global_options
’ is
used, and on subsequent calls ‘_arguments !$^global_options
’.
spec
s: actions
In each of the forms above the action
determines how completions
should be generated. Except for the ‘->``string
’ form below, the
action
will be executed by calling the _all_labels
function to
process all tag labels. No special handling of tags is needed unless a
function call introduces a new one.
The functions called to execute action
s will be called with the
elements of the array named by the ‘-O
name
’ option as arguments.
This can be used, for example, to pass the same set of options for the
compadd
builtin to all action
s.
The forms for action
are as follows.
-
This is useful where an argument is required but it is not possible or desirable to generate matches for it. Themessage
will be displayed but no completions listed. Note that even in this case the colon at the end of themessage
is needed; it may only be omitted when neither amessage
nor anaction
is given. -
(``item1
item2
...``)
One of a list of possible matches, for example::foo:(foo bar baz)
-
((item1\:desc1 ...))
Similar to the above, but with descriptions for each possible match. Note the backslash before the colon. For example,:foo:((a\:bar b\:baz))
The matches will be listed together with their descriptions if the
description
style is set with thevalues
tag in the context. -
->``string
In this form,
_arguments
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.Where
_arguments
encountersaction
in the ‘->``string
’ format, it will strip all leading and trailing whitespace fromstring
and set the arraystate
to the set of allstring
s for which an action is to be performed. The elements of the arraystate_descr
are assigned the correspondingmessage
field from eachoptarg
containing such anaction
.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
-R
option is given,_arguments
will instead return a status of 300 to indicate that$state
is to be handled.In addition to
$state
and$state_descr
,_arguments
also sets the global parameters ‘context
’, ‘line
’ and ‘opt_args
’ as described below, and does not reset any changes made to the special parameters such asPREFIX
andwords
. This gives the calling function the choice of resetting these parameters or propagating changes in them.A function calling
_arguments
with at least one action containing a ‘->``string
’ must therefore declare appropriate local parameters:local context state state_descr line typeset -A opt_args
to prevent
_arguments
from altering the global environment. -
{``eval-string``}
A string in braces is evaluated as shell code to generate matches. If the
eval-string
itself does not begin with an opening parenthesis or brace it is split into separate words before execution. -
= ``action
If theaction
starts with ‘=
’ (an equals sign followed by a space),_arguments
will insert the contents of theargument
field of the current context as the new first element in thewords
special array and increment the value of theCURRENT
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.This is most useful with one of the specifiers that restrict the words on the command line on which the
action
is to operate (the two- and three-colon forms above). One particular use is when anaction
itself causes_arguments
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_arguments
to be able to parse the line. -
word...
word...
This covers all forms other than those above. If theaction
starts with a space, the remaining list of words will be invoked unchanged.Otherwise it will be invoked with some extra strings placed after the first word; these are to be passed down as options to the
compadd
builtin. They ensure that the state specified by_arguments
, in particular the descriptions of options and arguments, is correctly passed to the completion command. These additional arguments are taken from the array parameter ‘expl
’; this will be set up before executing theaction
and hence may be referred to inside it, typically in an expansion of the form ‘$expl[@]
’ which preserves empty elements of the array.
During the performance of the action the array ‘line
’ 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 ‘opt_args
’ 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.
The parameter ‘context
’ is set when returning to the calling function
to perform an action of the form ‘->``string
’. It is set to an array
of elements corresponding to the elements of $state
. Each string of
the form ‘option``-opt``-``n
’ for the n
’th argument of the option
-opt
, or a string of the form ‘argument-``n
’ for the n
’th
argument. For ‘rest’ arguments, that is those in the list at the end not
handled by position, n
is the string ‘rest
’. For example, when
completing the argument of the -o
option, the name is ‘option-o-1
’,
while for the second normal (non-option-) argument it is ‘argument-2
’.
Furthermore, during the evaluation of the action
the context name in
the curcontext
parameter is altered to append the same string that is
stored in the context
parameter.
The option -C
tells _arguments
to modify the curcontext
parameter
for an action of the form ‘->``state
’. This is the standard parameter
used to keep track of the current context. Here it (and not the
context
array) should be made local to the calling function to avoid
passing back the modified value and should be initialised to the current
value at the start of the function:
local curcontext="$curcontext"
This is useful where it is not possible for multiple states to be valid together.
Grouping Options
Options can be grouped to simplify exclusion lists. A group is
introduced with ‘+
’ 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:
_arguments \
'(group2--x)-a' \
+ group1 \
-m \
'(group2)-n' \
+ group2 \
-x -y
If the name of a group is specified in the form ‘(``name``)
’ 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:
_arguments \
-a -b \
+ '(operation)' \
{-c,--compress}'[compress]' \
{-d,--decompress}'[decompress]' \
{-l,--list}'[list]'
If an option in a group appears on the command line, it is stored in the
associative array ‘opt_args
’ with ’group``-``option
’ as a key. In
the example above, a key ‘operation–c
’ is used if the option ‘-c
’ is
present on the command line.
Specifying Multiple Sets of Arguments
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.
Specifications before the first set and from any group are common to all sets. For example:
_arguments \
-a \
- set1 \
-c \
- set2 \
-d \
':arg:(x2 y2)'
This defines two sets. When the command line contains the option ‘-c
’,
the ‘-d
’ option and the argument will not be considered possible
completions. When it contains ‘-d
’ or an argument, the option ‘-c
’
will not be considered. However, after ‘-a
’ both sets will still be
considered valid.
As for groups, the name of a set may appear in exclusion lists, either alone or preceding a normal option or argument specification.
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 ‘-foo:*:...
’); here the option -foo
swallows up all remaining
arguments as described by the optarg
definitions.
Deriving spec
forms from the help output
The option ‘-``-
’ allows _arguments
to work out the names of long
options that support the ‘-``-help
’ option which is standard in many
GNU commands. The command word is called with the argument ‘-``-help
’
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.
In addition to options, ‘_arguments -``-
’ will try to deduce the types
of arguments available for options when the form ‘-``-``opt``=``val
’
is valid. It is also possible to provide hints by examining the help
text of the command and adding helpspec
of the form
‘pattern``:``message``:``action
’; note that other _arguments
spec
forms are not used. The pattern
is matched against the help
text for an option, and if it matches the message
and action
are
used as for other argument specifiers. The special case of ‘*:
’ means
both message
and action
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.
For example:
_arguments -- '*\*:toggle:(yes no)' \
'*=FILE*:file:_files' \
'*=DIR*:directory:_files -/' \
'*=PATH*:directory:_files -/'
Here, ‘yes
’ and ‘no
’ 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 ‘=FILE
’ in the description; and
directories will be completed for options whose description contains
‘=DIR
’ or ‘=PATH
’. 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:
-C, --directory=DIR change to directory DIR
so that the above specifications will cause directories to be completed
after ‘-``-directory
’, though not after ‘-C
’.
Note also that _arguments
tries to find out automatically if the
argument for an option is optional. This can be specified explicitly by
doubling the colon before the message
.
If the pattern
ends in ‘(-)
’, this will be removed from the pattern
and the action
will be used only directly after the ‘=
’, not in the
next word. This is the behaviour of a normal specification defined with
the form ‘=-
’.
By default, the command (with the option ‘–help
’) is run after
resetting all the locale categories (except for LC_CTYPE
) to ‘C
’. If
the localized help output is known to work, the option ‘-l
’ can be
specified after the ‘_arguments -``-
’ so that the command is run in
the current locale.
The ‘_arguments -``-
’ can be followed by the option ‘-i
patterns
’
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,
_arguments -- -i \
"(--(en|dis)able-FEATURE*)"
will cause completion to ignore the options ‘-``-enable-FEATURE
’ and
‘-``-disable-FEATURE
’ (this example is useful with GNU configure
).
The ‘_arguments -``-
’ form can also be followed by the option ‘-s
pair
’ to describe option aliases. The pair
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 _arguments
call.
For example, some configure
-script help output describes options only
as ‘-``-enable-foo
’, but the script also accepts the negated form
‘-``-disable-foo
’. To allow completion of the second form:
_arguments -- -s "((#s)--enable- --disable-)"
Miscellaneous notes
Finally, note that _arguments
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 _arguments
with other functions,
those functions should be called either before _arguments
, as an
action
within a spec
, or in handlers for ‘->``state
’ actions.
Here is a more general example of the use of _arguments
:
_arguments '-l+:left border:' \
'-format:paper size:(letter A4)' \
'*-copy:output file:_files::resolution:(300 600)' \
':postscript file:_files -g \*.\(ps\|eps\)' \
'*:page number:'
This describes three options: ‘-l
’, ‘-format
’, and ‘-copy
’. The
first takes one argument described as ‘left border
’ for which no
completion will be offered because of the empty action. Its argument may
come directly after the ‘-l
’ or it may be given as the next word on
the line.
The ‘-format
’ option takes one argument in the next word, described as
‘paper size
’ for which only the strings ‘letter
’ and ‘A4
’ will be
completed.
The ‘-copy
’ 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 ‘resolution
’) and will be completed from the strings
‘300
’ and ‘600
’.
The last two descriptions say what should be completed as arguments. The
first describes the first argument as a ‘postscript file
’ and makes
files ending in ‘ps
’ or ‘eps
’ be completed. The last description
gives all other arguments the description ‘page numbers
’ but does not
offer completions.
_cache_invalid
cache_identifier
This function returns status zero if the completions cache corresponding
to the given cache identifier needs rebuilding. It determines this by
looking up the cache-policy
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.
Example:
_example_caching_policy () {
# rebuild if cache is more than a week old
local -a oldp
oldp=( "$1"(Nm+7) )
(( $#oldp ))
}
_call_function
return
name
[ arg
... ]
If a function name
exists, it is called with the arguments arg
s. The
return
argument gives the name of a parameter in which the return
status from the function name
should be stored; if return
is empty
or a single hyphen it is ignored.
The return status of _call_function
itself is zero if the function
name
exists and was called and non-zero otherwise.
_call_program
[ -l
] [ -p
] tag
string
...
This function provides a mechanism for the user to override the use of
an external command. It looks up the command
style with the supplied
tag
. If the style is set, its value is used as the command to execute.
The string
s from the call to _call_program
, 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.
By default, the command is run in an environment where all the locale
categories (except for LC_CTYPE
) are reset to ‘C
’ by calling the
utility function _comp_locale
(see below). If the option ‘-l
’ is
given, the command is run with the current locale.
If the option ‘-p
’ is supplied it indicates that the command output is
influenced by the permissions it is run with. If the gain-privileges
style is set to true, _call_program
will make use of commands such as
sudo
, if present on the command-line, to match the permissions to
whatever the final command is likely to run under. When looking up the
gain-privileges
and command
styles, the command component of the
zstyle context will end with a slash (‘/
’) followed by the command
that would be used to gain privileges.
_combination
[ -s
pattern
] tag
style
spec
... field
opts
...
This function is used to complete combinations of values, for example
pairs of hostnames and usernames. The style
argument gives the style
which defines the pairs; it is looked up in a context with the tag
specified.
The style name consists of field names separated by hyphens, for example
‘users-hosts-ports
’. For each field for a value is already known, a
spec
of the form ‘field``=``pattern
’ is given. For example, if the
command line so far specifies a user ‘pws
’, the argument ‘users=pws
’
should appear.
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
field
s for which the value is known).
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 -s
to _combination
which specifies a pattern.
Typically this is a character class, as for example ‘-s "[:@]"
’ in the
case of the users-hosts
style. Each ‘field``=``pattern
’
specification restricts the completions which apply to elements of the
style with appropriately matching fields.
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
‘users-hosts-ports
’ or no matching hostname when a host is required,
the function ‘_hosts
’ will automatically be called.
If the same name is used for more than one field, in both the
‘field``=``pattern
’ 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.
All arguments after the required field name are passed to compadd
when
generating matches from the style value, or to the functions for the
fields if they are called.
_command_names
[ -e
| -
]
This function completes words that are valid at command position: names
of aliases, builtins, hashed commands, functions, and so on. With the
-e
flag, only hashed commands are completed. The -
flag is ignored.
_comp_locale
This function resets all the locale categories other than LC_CTYPE
to
‘C
’ so that the output from external commands can be easily analyzed
by the completion system. LC_CTYPE
retains the current value (taking
LC_ALL
and LANG
into account), ensuring that non-ASCII characters in
file names are still handled properly.
This function should normally be run only in a subshell, because the new
locale is exported to the environment. Typical usage would be
‘ $(_comp_locale; ``command
...)
’.
_completers
[ -p
]
This function completes names of completers.
-p
Include the leading underscore (‘_
’) in the matches.
_describe
[-12JVx
] [ -oO
| -t
tag
] descr
name1
[
name2
] [ opt
... ]
[ -``-
name1
[ name2
] [ opt
... ] ... ]
This function associates completions with descriptions. Multiple groups
separated by -``-
can be supplied, potentially with different
completion options opt
s.
The descr
is taken as a string to display above the matches if the
format
style for the descriptions
tag is set. This is followed by
one or two names of arrays followed by options to pass to compadd
. The
array name1
contains the possible completions with their descriptions
in the form ‘completion``:``description
’. Any literal colons in
completion
must be quoted with a backslash. If a name2
is given, it
should have the same number of elements as name1
; in this case the
corresponding elements are added as possible completions instead of the
completion
strings from name1
. The completion list will retain the
descriptions from name1
. Finally, a set of completion options can
appear.
If the option ‘-o
’ appears before the first argument, the matches
added will be treated as names of command options (N.B. not shell
options), typically following a ‘-
’, ‘-``-
’ or ‘+
’ on the command
line. In this case _describe
uses the prefix-hidden
, prefix-needed
and verbose
styles to find out if the strings should be added as
completions and if the descriptions should be shown. Without the ‘-o
’
option, only the verbose
style is used to decide how descriptions are
shown. If ‘-O
’ is used instead of ‘-o
’, command options are
completed as above but _describe
will not handle the prefix-needed
style.
With the -t
option a tag
can be specified. The default is ‘values
’
or, if the -o
option is given, ‘options
’.
The options -1
, -2
, -J
, -V
, -x
are passed to _next_label
.
If selected by the list-grouped
style, strings with the same
description will appear together in the list.
_describe
uses the _all_labels
function to generate the matches, so
it does not need to appear inside a loop over tag labels.
_description
[ -x
] [ -12VJ
] tag
name
descr
[ spec
... ]
This function is not to be confused with the previous one; it is used as
a helper function for creating options to compadd
. It is buried inside
many of the higher level completion functions and so often does not need
to be called directly.
The styles listed below are tested in the current context using the
given tag
. The resulting options for compadd
are put into the array
named name
(this is traditionally ‘expl
’, but this convention is not
enforced). The description for the corresponding set of matches is
passed to the function in descr
.
The styles tested are: format
, hidden
, matcher
, ignore-line
,
ignored-patterns
, group-name
and sort
. The format
style is first
tested for the given tag
and then for the descriptions
tag if no
value was found, while the remainder are only tested for the tag given
as the first argument. The function also calls _setup
which tests some
more styles.
The string returned by the format
style (if any) will be modified so
that the sequence ‘%d
’ is replaced by the descr
given as the third
argument without any leading or trailing white space. If, after removing
the white space, the descr
is the empty string, the format style will
not be used and the options put into the name
array will not contain
an explanation string to be displayed above the matches.
If _description
is called with more than three arguments, the
additional spec
s should be of the form ‘char``:``str
’. These supply
escape sequence replacements for the format
style: every appearance of
‘%``char
’ will be replaced by string
.
If the -x
option is given, the description will be passed to compadd
using the -x
option instead of the default -X
. This means that the
description will be displayed even if there are no corresponding
matches.
The options placed in the array name
take account of the group-name
style, so matches are placed in a separate group where necessary. The
group normally has its elements sorted (by passing the option -J
to
compadd
), but if an option starting with ‘-V
’, ‘-J
’, ‘-1
’, or
‘-2
’ is passed to _description
, that option will be included in
the array. Hence it is possible for the completion group to be unsorted
by giving the option ‘-V
’, ‘-1V
’, or ‘-2V
’.
In most cases, the function will be used like this:
local expl
_description files expl file
compadd "$expl[@]" - "$files[@]"
Note the use of the parameter expl
, the hyphen, and the list of
matches. Almost all calls to compadd
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.
_dir_list
[ -s
sep
] [ -S
]
Complete a list of directory names separated by colons (the same format
as $PATH
).
-
-s
sep
Usesep
as separator between items.sep
defaults to a colon (‘:
’). -
-S
Addsep
instead of slash (‘/
’) as an autoremoveable suffix.
_dispatch
context string
...
This sets the current context to context
and looks for completion
functions to handle this context by hunting through the list of command
names or special contexts (as described above for compdef
) given as
string
s. The first completion function to be defined for one of the
contexts in the list is used to generate matches. Typically, the last
string
is -default-
to cause the function for default completion to
be used as a fallback.
The function sets the parameter $service
to the string
being tried,
and sets the context/command
field (the fourth) of the $curcontext
parameter to the context
given as the first argument.
_email_addresses
[ -c
] [ -n
plugin
]
Complete email addresses. Addresses are provided by plugins.
-
-c
Complete barelocalhost@domain.tld
addresses, without a name part or a comment. Without this option, RFC822 ‘Firstname Lastname
<``address``>
’ strings are completed. -
-n
plugin
Complete aliases fromplugin
.
The following plugins are available by default: _email-ldap
(see the
filter
style), _email-local
(completes user``@``hostname
Unix
addresses), _email-mail
(completes aliases from ~/.mailrc
),
_email-mush
, _email-mutt
, and _email-pine
.
Addresses from the _email-``foo
plugin are added under the tag
‘email-``foo
’.
Writing plugins
Plugins are written as separate functions with names starting with
‘_email-
’. They are invoked with the -c
option and compadd
options. They should either do their own completion or set the $reply
array to a list of ‘alias``:``address
’ elements and return 300
. New
plugins will be picked up and run automatically.
_files
The function _files
is a wrapper around _path_files
. It supports all
of the same functionality, with some enhancements — notably, it respects
the list-dirs-first
style, and it allows users to override the
behaviour of the -g
and -/
options with the file-patterns
style.
_files
should therefore be preferred over _path_files
in most cases.
This function accepts the full set of options allowed by _path_files
,
described below.
_gnu_generic
This function is a simple wrapper around the _arguments
function
described above. It can be used to determine automatically the long
options understood by commands that produce a list when passed the
option ‘-``-help
’. 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 foo
and bar
, use
compdef _gnu_generic foo bar
after the call to compinit
.
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 ‘-``-help
’.
_guard
[ options
] pattern descr
This function displays descr
if pattern
matches the string to be
completed. It is intended to be used in the action
for the
specifications passed to _arguments
and similar functions.
The return status is zero if the message was displayed and the word to complete is not empty, and non-zero otherwise.
The pattern
may be preceded by any of the options understood by
compadd
that are passed down from _description
, namely -M
, -J
,
-V
, -1
, -2
, -n
, -F
and -X
. All of these options will be
ignored. This fits in conveniently with the argument-passing conventions
of actions for _arguments
.
As an example, consider a command taking the options -n
and -none
,
where -n
must be followed by a numeric value in the same word. By
using:
_arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'
_arguments
can be made to both display the message ‘numeric value
’
and complete options after ‘-n<TAB>
’. If the ‘-n
’ is already
followed by one or more digits (the pattern passed to _guard
) only the
message will be displayed; if the ‘-n
’ is followed by another
character, only options are completed.
_message
[ -r12
] [ -VJ
group
] descr
_message -e
[ tag
] descr
The descr
is used in the same way as the third argument to the
_description
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.
The format
style is examined with the messages
tag to find a
message; the usual tag, descriptions
, is used only if the style is not
set with the former.
If the -r
option is given, no style is used; the descr
is taken
literally as the string to display. This is most useful when the descr
comes from a pre-processed argument list which already contains an
expanded description. Note that this option does not disable the
‘%
’-sequence parsing done by compadd
.
The -12VJ
options and the group
are passed to compadd
and hence
determine the group the message string is added to.
The second -e
form gives a description for completions with the tag
tag
to be shown even if there are no matches for that tag. This form
is called by _arguments
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 $curtag
; 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, compstate[insert]
is cleared, so
additional matches generated later are not inserted on the command line.
_multi_parts
[ -i
] sep
array
The argument sep
is a separator character. The array
may be either
the name of an array parameter or a literal array in the form ‘(foo bar``)
’, a parenthesised list of words separated by whitespace. The
possible completions are the strings from the array. However, each chunk
delimited by sep
will be completed separately. For example, the _tar
function uses ‘_multi_parts
/
patharray
’ to complete partial file
paths from the given array of complete file paths.
The -i
option causes _multi_parts
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.
Like other utility functions, this function accepts the ‘-V
’, ‘-J
’,
‘-1
’, ‘-2
’, ‘-n
’, ‘-f
’, ‘-X
’, ‘-M
’, ‘-P
’, ‘-S
’,
‘-r
’, ‘-R
’, and ‘-q
’ options and passes them to the compadd
builtin.
_next_label
[ -x
] [ -12VJ
] tag
name
descr
[ option
... ]
This function is used to implement the loop over different tag labels
for a particular tag as described above for the tag-order
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 _tags
or
_requested
.
The -x12VJ
options and the first three arguments are passed to the
_description
function. Where appropriate the tag
will be replaced by
a tag label in this call. Any description given in the tag-order
style
is preferred to the descr
passed to _next_label
.
The option
s given after the descr
are set in the parameter given by
name
, and hence are to be passed to compadd
or whatever function is
called to add the matches.
Here is a typical use of this function for the tag foo
. The call to
_requested
determines if tag foo
is required at all; the loop over
_next_label
handles any labels defined for the tag in the tag-order
style.
local expl ret=1
...
if _requested foo; then
...
while _next_label foo expl '...'; do
compadd "$expl[@]" ... && ret=0
done
...
fi
return ret
_normal
[ -P
| -p
precommand
]
This is the standard function called to handle completion outside any
special -``context``-
. It is called both to complete the command word
and also the arguments for a command. In the second case, _normal
looks for a special completion for that command, and if there is none it
uses the completion for the -default-
context.
A second use is to reexamine the command line specified by the $words
array and the $CURRENT
parameter after those have been modified. For
example, the function _precommand
, which completes after precommand
specifiers such as nohup
, removes the first word from the words
array, decrements the CURRENT
parameter, then calls ‘_normal -p $service
’. The effect is that ‘nohup
cmd ...
’ is treated in the
same way as ‘cmd ...
’.
-
-P
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. ‘zsh -c
’). -
-p
precommand
Appendprecommand
to the list of precommands. This option should be used in nearly all cases in which-P
is not applicable.
If the command name matches one of the patterns given by one of the
options -p
or -P
to compdef
, the corresponding completion function
is called and then the parameter _compskip
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 -first-
context.
_options
This can be used to complete the names of shell options. It provides a
matcher specification that ignores a leading ‘no
’, ignores underscores
and allows upper-case letters to match their lower-case counterparts
(for example, ‘glob
’, ‘noglob
’, ‘NO_GLOB
’ are all completed). Any
arguments are propagated to the compadd
builtin.
_options_set
and _options_unset
These functions complete only set or unset options, with the same
matching specification used in the _options
function.
Note that you need to uncomment a few lines in the _main_complete
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.
_parameters
This is used to complete the names of shell parameters.
The option ‘-g
pattern
’ limits the completion to parameters whose
type matches the pattern
. The type of a parameter is that shown by
‘print ${(t)``param``}
’, hence judicious use of ‘*
’ in pattern
is probably necessary.
All other arguments are passed to the compadd
builtin.
_path_files
This function is used throughout the completion system to complete
filenames. It allows completion of partial paths. For example, the
string ‘/u/i/s/sig
’ may be completed to ‘/usr/include/sys/signal.h
’.
The options accepted by both _path_files
and _files
are:
-
-f
Complete all filenames. This is the default. -
-/
Specifies that only directories should be completed. -
-g
pattern
Specifies that only files matching thepattern
should be completed. -
-W
paths
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,paths
may be the name of an array parameter, a literal list of paths enclosed in parentheses or an absolute pathname. -
-F
ignored-files
This behaves as for the corresponding option to thecompadd
builtin. It gives direct control over which filenames should be ignored. If the option is not present, theignored-patterns
style is used.
Both _path_files
and _files
also accept the following options which
are passed to compadd
: ‘-J
’, ‘-V
’, ‘-1
’, ‘-2
’, ‘-n
’, ‘-X
’,
‘-M
’, ‘-P
’, ‘-S
’, ‘-q
’, ‘-r
’, and ‘-R
’.
Finally, the _path_files
function uses the styles expand
,
ambiguous
, special-dirs
, list-suffixes
and file-sort
described
above.
_pick_variant
[ -b
builtin-label
] [ -c
command
] [
-r
name
]
``label``=``pattern
... label
[ arg
... ]
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.
The command to run is taken from the first element of the array words
unless this is overridden by the option -c
. 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
label``=``pattern
; if the output of ‘command
arg
...’ contains
pattern
, then label
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.
If the ‘-b
builtin-label
’ is given, the command is tested to see if
it is provided as a shell builtin, possibly autoloaded; if so, the label
builtin-label
is selected as the label for the variant.
If the ‘-r
name
’ is given, the label
picked is stored in the
parameter named name
.
The results are also cached in the _cmd_variant
associative array
indexed by the name of the command run.
_regex_arguments
name
spec
...
This function generates a completion function name
which matches the
specifications spec
s, a set of regular expressions as described below.
After running _regex_arguments
, the function name
should be called
as a normal completion function. The pattern to be matched is given by
the contents of the words
array up to the current cursor position
joined together with null characters; no quotation is applied.
The arguments are grouped as sets of alternatives separated by ‘|
’,
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.
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 action
s
for the corresponding patterns are executed. In this case, nothing is
stripped from the command line string. The order of evaluation of the
action
s can be determined by the tag-order
style; the various
formats supported by _alternative
can be used in action
. The descr
is used for setting up the array parameter expl
.
Specification arguments take one of following forms, in which
metacharacters such as ‘(
’, ‘)
’, ‘#
’ and ‘|
’ should be quoted.
-
/``pattern``/
[%``lookahead``%
] [-``guard
] [:``tag``:``descr``:``action
]
This is a single primitive component. The function tests whether the combined pattern ‘(#b)((#B)``pattern``)``lookahead``*
’ matches the command line string. If so, ‘guard
’ is evaluated and its return status is examined to determine if the test has succeeded. Thepattern
string ‘[]
’ is guaranteed never to match. Thelookahead
is not stripped from the command line before the next pattern is examined.The argument starting with
:
is used in the same manner as an argument to_alternative
.A component is used as follows:
pattern
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 theaction
is used to generate matches to insert at that point. -
/``pattern``/+
[%``lookahead``%
] [-``guard
] [:``tag``:``descr``:``action
]
This is similar to ‘/``pattern``/
...’ 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. -
/``pattern``/-
[%``lookahead``%
] [-``guard
] [:``tag``:``descr``:``action
]
This is similar to ‘/``pattern``/
...’ but theaction
s of the current and previously matched patterns are ignored even if the following ‘pattern
’ matches the empty string. -
(
spec
)
Parentheses may be used to groupsspec
s; note each parenthesis is a single argument to_regex_arguments
. -
spec
#
This allows any number of repetitions ofspec
. -
spec
spec
The twospec
s are to be matched one after the other as described above. -
spec
|
spec
Either of the twospec
s can be matched.
The function _regex_words
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.
Examples:
_regex_arguments _tst /$'[^\0]#\0'/ \
/$'[^\0]#\0'/ :'compadd aaa'
This generates a function _tst
that completes aaa
as its only
argument. The tag
and description
for the action have been omitted
for brevity (this works but is not recommended in normal use). The first
component matches the command word, which is arbitrary; the second
matches any argument. As the argument is also arbitrary, any following
component would not depend on aaa
being present.
_regex_arguments _tst /$'[^\0]#\0'/ \
/$'aaa\0'/ :'compadd aaa'
This is a more typical use; it is similar, but any following patterns
would only match if aaa
was present as the first argument.
_regex_arguments _tst /$'[^\0]#\0'/ \( \
/$'aaa\0'/ :'compadd aaa' \
/$'bbb\0'/ :'compadd bbb' \) \#
In this example, an indefinite number of command arguments may be
completed. Odd arguments are completed as aaa
and even arguments as
bbb
. Completion fails unless the set of aaa
and bbb
arguments
before the current one is matched correctly.
_regex_arguments _tst /$'[^\0]#\0'/ \
\( /$'aaa\0'/ :'compadd aaa' \| \
/$'bbb\0'/ :'compadd bbb' \) \#
This is similar, but either aaa
or bbb
may be completed for any
argument. In this case _regex_words
could be used to generate
_regex_words
tag
description
spec
...
This function can be used to generate arguments for the
_regex_arguments
command which may be inserted at any point where a
set of rules is expected. The tag
and description
give a standard
tag and description pertaining to the current context. Each spec
contains two or three arguments separated by a colon: note that there is
no leading colon in this case.
Each spec
gives one of a set of words that may be completed at this
point, together with arguments. It is thus roughly equivalent to the
_arguments
function when used in normal (non-regex) completion.
The part of the spec
before the first colon is the word to be
completed. This may contain a *
; the entire word, before and after the
*
is completed, but only the text before the *
is required for the
context to be matched, so that further arguments may be completed after
the abbreviated form.
The second part of spec
is a description for the word being completed.
The optional third part of the spec
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.
The option -t
term
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 -s
sep
to _values
.
The result of the processing by _regex_words
is placed in the array
reply
, which should be made local to the calling function. If the set
of words and arguments may be matched repeatedly, a #
should be
appended to the generated array at that point.
For example:
local -a reply
_regex_words mydb-commands 'mydb commands' \
'add:add an entry to mydb:$mydb_add_cmds' \
'show:show entries in mydb'
_regex_arguments _mydb "$reply[@]"
_mydb "$@"
This shows a completion function for a command mydb
which takes two
command arguments, add
and show
. show
takes no arguments, while
the arguments for add
have already been prepared in an array
mydb_add_cmds
, quite possibly by a previous call to _regex_words
.
_requested
[ -x
] [ -12VJ
] tag
[ name
descr
[
command
[ arg
... ] ]
This function is called to decide whether a tag already registered by a
call to _tags
(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:
_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
Note that the test for whether matches were generated is not performed
until the end of the _tags
loop. This is so that the user can set the
tag-order
style to specify a set of tags to be completed at the same
time.
If name
and descr
are given, _requested
calls the _description
function with these arguments together with the options passed to
_requested
.
If command
is given, the _all_labels
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:
local expl ret=1
_tags foo bar baz
while _tags; do
_requested foo expl 'description' \
compadd foobar foobaz && ret=0
...
(( ret )) || break
done
If the command
is not compadd
, it must nevertheless be prepared to
handle the same options.
_retrieve_cache
cache_identifier
This function retrieves completion information from the file given by
cache_identifier
, stored in a directory specified by the cache-path
style which defaults to ~/.zcompcache
. The return status is zero if
retrieval was successful. It will only attempt retrieval if the
use-cache
style is set, so you can call this function without worrying
about whether the user wanted to use the caching layer.
See _store_cache
below for more details.
_sep_parts
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
‘hosts=(ftp news)
’ the call ‘_sep_parts ’(foo bar)’ @ hosts
’ will
complete the string ‘f
’ to ‘foo
’ and the string ‘b@n
’ to
‘bar@news
’.
This function accepts the compadd
options ‘-V
’, ‘-J
’, ‘-1
’,
‘-2
’, ‘-n
’, ‘-X
’, ‘-M
’, ‘-P
’, ‘-S
’, ‘-r
’, ‘-R
’, and
‘-q
’ and passes them on to the compadd
builtin used to add the
matches.
_sequence
[ -s
sep
] [ -n
max
] [ -d
] function
[
-
] ...
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 -s
option. If -s
is
omitted it will use ‘,
’. Duplicate values are not matched unless -d
is specified. If there is a fixed or maximum number of items in the
list, this can be specified with the -n
option.
Common compadd
options are passed on to the function. It is possible
to use compadd
directly with _sequence
, though _values
may be more
appropriate in this situation.
_setup
tag
[ group
]
This function sets up the special parameters used by the completion
system appropriately for the tag
given as the first argument. It uses
the styles list-colors
, list-packed
, list-rows-first
,
last-prompt
, accept-exact
, menu
and force-list
.
The optional group
supplies the name of the group in which the matches
will be placed. If it is not given, the tag
is used as the group name.
This function is called automatically from _description
and hence is
not normally called explicitly.
_store_cache
cache_identifier
param
...
This function, together with _retrieve_cache
and _cache_invalid
,
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 _retrieve_cache
, even
in different instances of the shell.
The cache_identifier
specifies the file which the data should be
dumped to. The file is stored in a directory specified by the
cache-path
style which defaults to ~/.zcompcache
. The remaining
param
s arguments are the parameters to dump to the file.
The return status is zero if storage was successful. The function will
only attempt storage if the use-cache
style is set, so you can call
this function without worrying about whether the user wanted to use the
caching layer.
The completion function may avoid calling _retrieve_cache
when it
already has the completion data available as parameters. However, in
that case it should call _cache_invalid
to check whether the data in
the parameters and in the cache are still valid.
See the _perl_modules completion function for a simple example of the usage of the caching layer.
_tags
[ [ -C
name
] tag
... ]
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 tag-order
style.
Next, _tags
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 _requested
function should be
called (see above).
If ‘-C
name
’ is given, name
is temporarily stored in the
argument
field (the fifth) of the context in the curcontext
parameter during the call to _tags
; the field is restored on exit.
This allows _tags
to use a more specific context without having to
change and reset the curcontext
parameter (which has the same effect).
_tilde_files
Like _files
, but resolve leading tildes according to the rules of
filename expansion, so the suggested completions don’t start with a
‘~
’ even if the filename on the command-line does.
_values
[ -O
name
] [ -s
sep
] [ -S
sep
] [ -wC
] desc
spec
...
This is used to complete arbitrary keywords (values) and their arguments, or lists of such combinations.
If the first argument is the option ‘-O
name
’, it will be used in
the same way as by the _arguments
function. In other words, the
elements of the name
array will be passed to compadd
when executing
an action.
If the first argument (or the first argument after ‘-O
name
’) is
‘-s
’, 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
‘_values -s
’ appear in the same word on the command line, unlike
completion using _arguments
. If this option is not present, only a
single value will be completed per word.
Normally, _values
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 -w
option is given, other arguments are
examined as well.
The first non-option argument, desc
, is used as a string to print as a
description before listing the values.
All other arguments describe the possible values and their arguments in
the same format used for the description of options by the _arguments
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.
The character separating a value from its argument can be set using the
option -S
(like -s
, 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.
Example:
_values -s , 'description' \
'*foo[bar]' \
'(two)*one[number]:first count:' \
'two[another number]::second count:(1 2 3)'
This describes three possible values: ‘foo
’, ‘one
’, and ‘two
’. The
first is described as ‘bar
’, takes no argument and may appear more
than once. The second is described as ‘number
’, may appear more than
once, and takes one mandatory argument described as ‘first count
’; no
action is specified, so it will not be completed. The ‘(two)
’ at the
beginning says that if the value ‘one
’ is on the line, the value
‘two
’ will no longer be considered a possible completion. Finally,
the last value (‘two
’) is described as ‘another number
’ and takes an
optional argument described as ‘second count
’ for which the
completions (to appear after an ‘=
’) are ‘1
’, ‘2
’, and ‘3
’. The
_values
function will complete lists of these values separated by
commas.
Like _arguments
, this function temporarily adds another context name
component to the arguments element (the fifth) of the current context
while executing the action
. Here this name is just the name of the
value for which the argument is completed.
The style verbose
is used to decide if the descriptions for the values
(but not those for the arguments) should be printed.
The associative array val_args
is used to report values and their
arguments; this works similarly to the opt_args
associative array used
by _arguments
. Hence the function calling _values
should declare the
local parameters state
, state_descr
, line
, context
and
val_args
:
local context state state_descr line
typeset -A val_args
when using an action of the form ‘->``string
’. With this function the
context
parameter will be set to the name of the value whose argument
is to be completed. Note that for _values
, the state
and
state_descr
are scalars rather than arrays. Only a single matching
state is returned.
Note also that _values
normally adds the character used as the
separator between values as an auto-removable suffix (similar to a ‘/
’
after a directory). However, this is not possible for a ‘->``string
’
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 x
as a suffix by passing the options ‘-qS
x
’ either
directly or indirectly to compadd
.
The option -C
is treated in the same way as it is by _arguments
. In
that case the parameter curcontext
should be made local instead of
context
(as described above).
_wanted
[ -x
] [ -C
name
] [ -12VJ
] tag
name
descr
command
[ arg
...]
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.
The arguments to _wanted
are the same as those to _requested
, i.e.
arguments to be passed to _description
. However, in this case the
command
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 _wanted
.
Hence to offer only one tag and immediately add the corresponding matches with the given description:
local expl
_wanted tag expl 'description' \
compadd matches...
Note that, as for _requested
, the command
must be able to accept
options to be passed down to compadd
.
Like _tags
this function supports the -C
option to give a different
name for the argument context field. The -x
option has the same
meaning as for _description
.
_widgets
[ -g
pattern
]
This function completes names of zle widgets (see
Widgets). The pattern
, if present,
is matched against values of the $widgets
special parameter,
documented in The zsh/zleparameter
Module.
20.7 Completion System Variables
There are some standard variables, initialised by the _main_complete
function and then used from other functions.
The standard variables are:
-
_comp_caller_options
The completion system usessetopt
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_comp_caller_options
associative array. Option names, spelled in lowercase without underscores, are mapped to one or other of the strings ‘on
’ and ‘off
’. -
_comp_priv_prefix
Completion functions such as_sudo
can set the_comp_priv_prefix
array to a command prefix that may then be used by_call_program
to match the privileges when calling programs to generate matches.
Two more features are offered by the _main_complete
function. The
arrays compprefuncs
and comppostfuncs
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.
20.8 Completion Directories
In the source distribution, the files are contained in various
subdirectories of the Completion
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 fpath
than the standard directory where it appears.
-
Base
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. -
Zsh
Functions for completing arguments of shell builtin commands and utility functions for this. Some of these are also used by functions from theUnix
directory. -
Unix
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 themount
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-``-help
option is supported. -
X
,AIX
,BSD
, ...
Completion and utility function for commands available only on some systems. These are not arranged hierarchically, so, for example, both theLinux
andDebian
directories, as well as theX
directory, may be useful on your system.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
21 Completion Using compctl
21.1 Types of completion
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
Completion System, and the
basic shell mechanisms which support it are described in Completion
Widgets. This chapter
describes the older compctl
command.
21.2 Description
compctl
[ -CDT
] options
[ command
... ]
compctl
[ -CDT
] options
[ -x
pattern
options
-
...
-``-
]
[ +
options
[ -x
... -``-
] ... [+
] ] [
command
... ]
compctl
-M
match-specs
...
compctl
-L
[ -CDTM
] [ command
... ]
compctl
+
command
...
Control the editor’s completion behavior according to the supplied set
of options
. Various editing commands, notably
expand-or-complete-word
, usually bound to tab, will attempt to
complete a word typed by the user, while others, notably
delete-char-or-list
, usually bound to ^D in EMACS editing mode, list
the possibilities; compctl
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.
21.3 Command Flags
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 -L
) may be
combined with any combination of the options
described subsequently in
Option Flags:
-
command
...
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=
, completion is tried with the pathname of the command.Any of the
command
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’foo*’
arranges for completion of the words of any command beginning withfoo
. 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-tn
in the flags for the pattern completion.Note that aliases are expanded before the command name is determined unless the
COMPLETE_ALIASES
option is set. Commands may not be combined with the-C
,-D
or-T
flags. -
-C
controls completion when the command word itself is being completed. If nocompctl -C
command has been issued, the names of any as aliases or functions) are completed. -
-D
controls default completion behavior for the arguments of commands not assigned any special behavior. If nocompctl -D
command has been issued, filenames are completed. -
-T
supplies completion flags to be used before any other processing is done, even before processing forcompctl
s defined for specific commands. This is especially useful when combined with extended completion (the-x
flag, see Extended Completion 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 ‘~
’ is too slow to be usable), you can usecompctl -T -x 's[~] C[0,[^/]#]' -k friends -S/ -tn
to complete the strings in the array
friends
after a ‘~
’. TheC[``...``]
argument is necessary so that this form of~
-completion is not tried after the directory name is finished. -
-L
no argument
If no argument is given,compctl
lists all defined completions in an abbreviated form; with a list ofoptions
, all completions with those flags set (not counting extended completion) are listed.
If the +
flag is alone and followed immediately by the command
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 -D
flag.
The form with -M
as the first and only option defines global matching
specifications (see Completion Matching
Control). The
match specifications given will be used for every completion attempt
(only when using compctl
, 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.:
compctl -M '' 'm:{a-zA-Z}={A-Za-z}'
This will first try completion without any global match specifications (the empty string) and, if that generates no matches, will try case insensitive completion.
21.4 Option Flags
[ -fcFBdeaRGovNAIOPZEnbjrzu/12
]
[ -k
array
] [ -g
globstring
] [ -s
subststring
]
[ -K
function
]
[ -Q
] [ -P
prefix
] [ -S
suffix
]
[ -W
file-prefix
] [ -H
num pattern
]
[ -q
] [ -X
explanation
] [ -Y
explanation
]
[ -y
func-or-var
] [ -l
cmd
] [ -h
cmd
] [ -U
]
[ -t
continue
] [ -J
name
] [ -V
name
]
[ -M
match-spec
]
The remaining options
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.
21.4.1 Simple Flags
These produce completion lists made up by the shell itself:
-
-f
Filenames and file system paths. -
-/
Just file system paths. -
-c
Command names, including aliases, shell functions, builtins and reserved words. -
-F
Function names. -
-B
Names of builtin commands. -
-m
Names of external commands. -
-w
Reserved words. -
-a
Alias names. -
-R
Names of regular (non-global) aliases. -
-G
Names of global aliases. -
-d
This can be combined with-F
,-B
,-w
,-a
,-R
and-G
to get names of disabled functions, builtins, reserved words or aliases. -
-e
This option (to show enabled commands) is in effect by default, but may be combined with-d
;-de
in combination with-F
,-B
,-w
,-a
,-R
and-G
will complete names of functions, builtins, reserved words or aliases whether or not they are disabled. -
-o
Names of shell options (see Options). -
-v
Names of any variable defined in the shell. -
-N
Names of scalar (non-array) parameters. -
-A
Array names. -
-I
Names of integer variables. -
-O
Names of read-only variables. -
-p
Names of parameters used by the shell (including special parameters). -
-Z
Names of shell special parameters. -
-E
Names of environment variables. -
-n
Named directories. -
-b
Key binding names. -
-j
Job names: the first word of the job leader’s command line. This is useful with thekill
builtin. -
-r
Names of running jobs. -
-z
Names of suspended jobs. -
-u
User names.
21.4.2 Flags with Arguments
These have user supplied arguments to determine how the list of completions is to be made up:
-
-k
array
Names taken from the elements of$``array
(note that the ‘$
’ does not appear on the command line). Alternatively, the argumentarray
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,compctl -k "(cputime filesize datasize stacksize coredumpsize resident descriptors)" limit
-
-g
globstring
Theglobstring
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 ‘*(/)
’ instead of ‘*/
’ for directories. Thefignore
special parameter is not applied to the resulting files. More than one pattern may be given separated by blanks. (Note that brace expansion is not part of globbing. Use the syntax ‘(either|or)
’ to match alternatives.) -
-s
subststring
Thesubststring
is split into words and these words are than expanded using all shell expansion mechanisms (see Expansion). The resulting words are taken as possible completions. Thefignore
special parameter is not applied to the resulting files. Note that-g
is faster for filenames. -
-K
function
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
-c
and-l
flags of theread
builtin. The function should set the variablereply
to an array containing the completions (one completion per element); note thatreply
should not be made local to the function. From such a function the command line can be accessed with the-c
and-l
flags to theread
builtin. For example,function whoson { reply=(`users`); } compctl -K whoson talk
completes only logged-on users after ‘
talk
’. Note that ‘whoson
’ must return an array, so ‘reply=‘users‘
’ would be incorrect. -
-H
num pattern
The possible completions are taken from the lastnum
history lines. Only words matchingpattern
are taken. Ifnum
is zero or negative the whole history is searched and ifpattern
is the empty string all words are taken (as with ‘*
’). A typical use iscompctl -D -f + -H 0 ''
which forces completion to look back in the history list for a word if no filename matches.
21.4.3 Control Flags
These do not directly specify types of name to be completed, but manipulate the options that do:
-
-Q
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 (-k
) so that the expression will not be evaluated until the complete line is executed, this option must be used. -
-P
prefix
Theprefix
is inserted just before the completed string; any initial part already typed will be completed and the wholeprefix
ignored for completion purposes. For example,compctl -j -P "%" kill
inserts a ‘%’ after the kill command and then completes job names.
-
-S
suffix
When a completion is found thesuffix
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. -
-W
file-prefix
With directoryfile-prefix
: for command, file, directory and globbing completion (options-c
,-f
,-/
,-g
), the file prefix is implicitly added in front of the completion. For example,compctl -/ -W ~/Mail maildirs
completes any subdirectories to any depth beneath the directory
~/Mail
, although that prefix does not appear on the command line. Thefile-prefix
may also be of the form accepted by the-k
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. -
-q
If used with a suffix as specified by the-S
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 theAUTO_REMOVE_SLASH
option. The option is most useful for list separators (comma, colon, etc.). -
-l
cmd
This option restricts the range of command line words that are considered to be arguments. If combined with one of the extended completion patterns ‘p[
...]
’, ‘r[
...]
’, or ‘R[
...]
’ (see Extended Completion 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 thecmd
supplied with the option. If thecmd
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,compctl -x 'r[-exec,;]' -l '' -- find
completes arguments between ‘
-exec
’ and the following ‘;
’ (or the end of the command line if there is no such string) as if they were a separate command line. -
-h
cmd
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-l
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 givencmd
. Ifcmd
is the empty string, the first part is completed as a command name, as with-l
. -
-U
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-K
option) which can examine the word components passed to it (or via theread
builtin’s-c
and-l
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 ifAUTO_MENU
is set and this flag is used. -
-y
func-or-var
The list provided by
func-or-var
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, iffunc-or-var
begins with a$
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-K
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 arrayreply
to the result. In both cases, the display list will only be retrieved after a complete list of matches has been created.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.
-
-X
explanation
Printexplanation
when trying completion on the current set of options. A ‘%n
’ 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-X
option (using the-J
or-V
option). If the same explanation string is given to multiple-X
options, the string appears only once (for each group) and the number of matches shown for the ‘%n
’ 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.The sequences
%B
,%b
,%S
,%s
,%U
, and%u
specify output attributes (bold, standout, and underline),%F
,%f
,%K
,%k
specify foreground and background colours, and%{``...``%}
can be used to include literal escape sequences as in prompts. -
-Y
explanation
Identical to-X
, except that theexplanation
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-K
or-y
options, allowing them to set variables. -
-t
continue
Thecontinue
-string contains a character that specifies which set of completion flags should be used next. It is useful:(i) With
-T
, or when trying a list of pattern completions, whencompctl
would usually continue with ordinary processing after finding matches; this can be suppressed with ‘-tn
’.(ii) With a list of alternatives separated by
+
, whencompctl
would normally stop when one of the alternatives generates matches. It can be forced to consider the next set of completions by adding ‘-t+
’ to the flags of the alternative before the ‘+
’.(iii) In an extended completion list (see below), when
compctl
would normally continue until a set of conditions succeeded, then use only the immediately following flags. With ‘-t-
’,compctl
will continue trying extended completions after the next ‘-
’; with ‘-tx
’ it will attempt completion with the default flags, in other words those before the ‘-x
’. -
-J
name
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 nameddefault
. 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.This can be useful with non-exclusive alternative completions. For example, in
compctl -f -J files -t+ + -v -J variables foo
both files and variables are possible completions, as the
-t+
forces both sets of alternatives before and after the+
to be considered at once. Because of the-J
options, however, all files are listed before all variables. -
-V
name
Like-J
, 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-J files
and-V files
are distinct. -
-1
If given together with the-V
option, makes only consecutive duplicates in the group be removed. Note that groups with and without this flag are in different name spaces. -
-2
If given together with the-J
or-V
option, makes all duplicates be kept. Again, groups with and without this flag are in different name spaces. -
-M
match-spec
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 thematch-spec
string is described in Completion Matching Control.
21.5 Alternative Completion
compctl
[ -CDT
] options
+
options
[ +
... ] [ +
]
command
...
The form with ‘+
’ specifies alternative options. Completion is tried
with the options before the first ‘+
’. If this produces no matches
completion is tried with the flags after the ‘+
’ and so on. If there
are no flags after the last ‘+
’ and a match has not been found up to
that point, default completion is tried. If the list of flags contains a
-t
with a +
character, the next list of flags is used even if the
current list produced matches.
Additional options are available that restrict completion to some part of the command line; this is referred to as ‘extended completion’.
21.6 Extended Completion
compctl
[ -CDT
] options
-x
pattern
options
-
...
-``-
[ command
... ]
compctl
[ -CDT
] options
[ -x
pattern
options
-
...
-``-
]
[ +
options
[ -x
... -``-
] ... [+
] ] [
command
... ]
The form with ‘-x
’ specifies extended completion for the commands
given; as shown, it may be combined with alternative completion using
‘+
’. Each pattern
is examined in turn; when a match is found, the
corresponding options
, as described in Option Flags
above, are used to generate possible completions. If no pattern
matches, the options
given before the -x
are used.
Note that each pattern should be supplied as a single argument and should be quoted to prevent expansion of metacharacters by the shell.
A pattern
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
‘c``[
...][
...]
’, 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.
The elements may be any of the following:
-
s[``string``]
...
Matches if the current word on the command line starts with one of the strings given in brackets. Thestring
is not removed and is not part of the completion. -
S[``string``]
...
Likes[``string``]
except that thestring
is part of the completion. -
p[``from``,``to``]
...
Matches if the number of the current word is between one of thefrom
andto
pairs inclusive. The comma andto
are optional;to
defaults to the same value asfrom
. The numbers may be negative:-``n
refers to then
’th last word on the line. -
c[``offset``,``string``]
...
Matches if thestring
matches the word offset byoffset
from the current word position. Usuallyoffset
will be negative. -
C[``offset``,``pattern``]
...
Likec
but using pattern matching instead. -
w[``index``,``string``]
...
Matches if the word in positionindex
is equal to the correspondingstring
. Note that the word count is made after any alias expansion. -
W[``index``,``pattern``]
...
Likew
but using pattern matching instead. -
n[``index``,``string``]
...
Matches if the current word containsstring
. Anything up to and including theindex
th occurrence of this string will not be considered part of the completion, but the rest will.index
may be negative to count from the end: in most cases,index
will be 1 or -1. For example,compctl -s '`users`' -x 'n[1,@]' -k hosts -- talk
will usually complete usernames, but if you insert an
@
after the name, names from the arrayhosts
(assumed to contain hostnames, though you must make the array yourself) will be completed. Other commands such asrcp
can be handled similarly. -
N[``index``,``string``]
...
Liken
except that the string will be taken as a character class. Anything up to and including theindex
th occurrence of any of the characters instring
will not be considered part of the completion. -
m[``min``,``max``]
...
Matches if the total number of words lies betweenmin
andmax
inclusive. -
r[``str1``,``str2``]
...
Matches if the cursor is after a word with prefixstr1
. If there is also a word with prefixstr2
on the command line after the one matched bystr1
it matches only if the cursor is before this word. If the comma andstr2
are omitted, it matches if the cursor is after a word with prefixstr1
. -
R[``str1``,``str2``]
...
Liker
but using pattern matching instead. -
q[``str``]
...
Matches the word currently being completed is in single quotes and thestr
begins with the letter ‘s’, or if completion is done in double quotes andstr
starts with the letter ‘d’, or if completion is done in backticks andstr
starts with a ‘b’.
21.7 Example
compctl -u -x 's[+] c[-1,-f],s[-f+]' \
-g '~/Mail/*(:t)' - 's[-f],c[-1,-f]' -f -- mail
This is to be interpreted as follows:
If the current command is mail
, then
if ((the current word begins with
+
and the previous word is-f
) or (the current word begins with-f+
)), then complete the non-directory part (the ‘:t
’ glob modifier) of files in the directoryif the current word begins with
-f
or the previous word was-f
, then complete any file; elsecomplete user names.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 22 Zsh Modules
- 22.1 Description
- 22.2 The zsh/attr Module
- 22.3 The zsh/cap Module
- 22.4 The zsh/clone Module
- 22.5 The zsh/compctl Module
- 22.6 The zsh/complete Module
- 22.7 The zsh/complist Module
- 22.8 The zsh/computil Module
- 22.9 The zsh/curses Module
- 22.10 The zsh/datetime Module
- 22.11 The zsh/db/gdbm Module
- 22.12 The zsh/deltochar Module
- 22.13 The zsh/example Module
- 22.14 The zsh/files Module
- 22.15 The zsh/langinfo Module
- 22.16 The zsh/mapfile Module
- 22.17 The zsh/mathfunc Module
- 22.18 The zsh/nearcolor Module
- 22.19 The zsh/newuser Module
- 22.20 The zsh/parameter Module
- 22.21 The zsh/pcre Module
- 22.22 The zsh/param/private Module
- 22.23 The zsh/regex Module
- 22.24 The zsh/sched Module
- 22.25 The zsh/net/socket Module
- 22.26 The zsh/stat Module
- 22.27 The zsh/system Module
- 22.28 The zsh/net/tcp Module
- 22.29 The zsh/termcap Module
- 22.30 The zsh/terminfo Module
- 22.31 The zsh/zftp Module
- 22.32 The zsh/zle Module
- 22.33 The zsh/zleparameter Module
- 22.34 The zsh/zprof Module
- 22.35 The zsh/zpty Module
- 22.36 The zsh/zselect Module
- 22.37 The zsh/zutil Module
22 Zsh Modules
22.1 Description
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 zmodload
command, see Shell Builtin
Commands.
The modules that are bundled with the zsh distribution are:
-
zsh/attr
Builtins for manipulating extended attributes (xattr). -
zsh/cap
Builtins for manipulating POSIX.1e (POSIX.6) capability (privilege) sets. -
zsh/clone
A builtin that can clone a running shell onto another terminal. -
zsh/compctl
Thecompctl
builtin for controlling completion. -
zsh/complete
The basic completion code. -
zsh/complist
Completion listing extensions. -
zsh/computil
A module with utility builtins needed for the shell function based completion system. -
zsh/curses
curses windowing commands -
zsh/datetime
Some date/time commands and parameters. -
zsh/db/gdbm
Builtins for managing associative array parameters tied to GDBM databases. -
zsh/deltochar
A ZLE function duplicating EMACS’zap-to-char
. -
zsh/example
An example of how to write a module. -
zsh/files
Some basic file manipulation commands as builtins. -
zsh/langinfo
Interface to locale information. -
zsh/mapfile
Access to external files via a special associative array. -
zsh/mathfunc
Standard scientific functions for use in mathematical evaluations. -
zsh/nearcolor
Map colours to the nearest colour in the available palette. -
zsh/newuser
Arrange for files for new users to be installed. -
zsh/parameter
zsh/pcre
Interface to the PCRE library. -
zsh/param/private
Builtins for managing private-scoped parameters in function context. -
zsh/regex
Interface to the POSIX regex library. -
zsh/sched
A builtin that provides a timed execution facility within the shell. -
zsh/net/socket
Manipulation of Unix domain sockets -
zsh/stat
A builtin command interface to thestat
system call. -
zsh/system
A builtin interface to various low-level system features. -
zsh/net/tcp
Manipulation of TCP sockets -
zsh/termcap
Interface to the termcap database. -
zsh/terminfo
Interface to the terminfo database. -
zsh/zftp
A builtin FTP client. -
zsh/zle
The Zsh Line Editor, including thebindkey
andvared
builtins. -
zsh/zleparameter
Access to internals of the Zsh Line Editor via parameters. -
zsh/zprof
A module allowing profiling for shell functions. -
zsh/zpty
A builtin for starting a command in a pseudo-terminal. -
zsh/zselect
Block and return when file descriptors are ready. -
zsh/zutil
Some utility builtins, e.g. the one for supporting configuration via styles.
22.2 The zsh/attr Module
The zsh/attr
module is used for manipulating extended attributes. The
-h
option causes all commands to operate on symbolic links instead of
their targets. The builtins in this module are:
zgetattr
[ -h
] filename
attribute
[ parameter
]
Get the extended attribute attribute
from the specified filename
. If
the optional argument parameter
is given, the attribute is set on that
parameter instead of being printed to stdout.
zsetattr
[ -h
] filename
attribute
value
Set the extended attribute attribute
on the specified filename
to
value
.
zdelattr
[ -h
] filename
attribute
Remove the extended attribute attribute
from the specified filename
.
zlistattr
[ -h
] filename
[ parameter
]
List the extended attributes currently set on the specified filename
.
If the optional argument parameter
is given, the list of attributes is
set on that parameter instead of being printed to stdout.
zgetattr
and zlistattr
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.
22.3 The zsh/cap Module
The zsh/cap
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:
cap
[ capabilities
]
Change the shell’s process capability sets to the specified
capabilities
, otherwise display the shell’s current capabilities.
getcap
filename
...
This is a built-in implementation of the POSIX standard utility. It
displays the capability sets on each specified filename
.
setcap
capabilities
filename
...
This is a built-in implementation of the POSIX standard utility. It sets
the capability sets on each specified filename
to the specified
capabilities
.
22.4 The zsh/clone Module
The zsh/clone
module makes available one builtin command:
clone
tty
Creates a forked instance of the current shell, attached to the
specified tty
. In the new shell, the PID
, PPID
and TTY
special
parameters are changed appropriately. $!
is set to zero in the new
shell, and to the new shell’s PID in the original shell.
The return status of the builtin is zero in both shells if successful, and non-zero on error.
The target of clone
should be an unused terminal, such as an unused
virtual console or a virtual terminal created by
xterm -e sh -c 'trap : INT QUIT TSTP; tty;
while :; do sleep 100000000; done'
Some words of explanation are warranted about this long xterm command line: when doing clone on a pseudo-terminal, some other session ("session" 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:
- 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)
- the cloned shell will have job control disabled, and the job control keys (control-C, control-\ and control-Z) will not work.
This does not apply when cloning to an unused vc.
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.
clone
is mostly useful as a shell built-in replacement for openvt.
22.5 The zsh/compctl Module
The zsh/compctl
module makes available two builtin commands.
compctl
, is the old, deprecated way to control completions for ZLE.
See Completion Using
compctl. The
other builtin command, compcall
can be used in user-defined completion
widgets, see Completion
Widgets.
22.6 The zsh/complete Module
The zsh/complete
module makes available several builtin commands which
can be used in user-defined completion widgets, see Completion
Widgets.
22.7 The zsh/complist Module
The zsh/complist
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.
22.7.1 Colored completion listings
Whenever one of the parameters ZLS_COLORS
or ZLS_COLOURS
is set and
the zsh/complist
module is loaded or linked into the shell, completion
lists will be colored. Note, however, that complist
will not
automatically be loaded if it is not linked in: on systems with dynamic
loading, ‘zmodload zsh/complist
’ is required.
The parameters ZLS_COLORS
and ZLS_COLOURS
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
ls
command: a colon-separated list of specifications of the form
‘name``=``value
’. The name
may be one of the following strings,
most of which specify file types for which the value
will be used. The
strings and their default values are:
-
no 0
for normal text (i.e. when displaying something other than a matched file) -
fi 0
for regular files -
di 32
for directories -
ln 36
for symbolic links. If this has the special valuetarget
, symbolic links are dereferenced and the target file used to determine the display format. -
pi 31
for named pipes (FIFOs) -
so 33
for sockets -
bd 44;37
for block devices -
cd 44;37
for character devices -
or
none
for a symlink to nonexistent file (default is the value defined forln
) -
mi
none
for a non-existent file (default is the value defined forfi
); this code is currently not used -
su 37;41
for files with setuid bit set -
sg 30;43
for files with setgid bit set -
tw 30;42
ow 34;43
sa
none
for files with an associated suffix alias; this is only tested after specific suffixes, as described below -
st 37;44
ex 35
lc \e[
for the left code (see below) -
rc m
for the right code -
tc 0
for the character indicating the file type printed after filenames if theLIST_TYPES
option is set -
sp 0
for the spaces printed after matches to align the next column -
ec
none
for the end code
Apart from these strings, the name
may also be an asterisk (‘*
’)
followed by any string. The value
given for such a string will be used
for all files whose name ends with the string. The name
may also be an
equals sign (‘=
’) followed by a pattern; the EXTENDED_GLOB
option
will be turned on for evaluation of the pattern. The value
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).
The leading-equals form also allows different parts of the displayed
strings to be colored differently. For this, the pattern has to use the
‘(#b)
’ globbing flag and pairs of parentheses surrounding the parts
of the strings that are to be colored differently. In this case the
value
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 ‘=(#b)(?)*(?)=0=3=7
’ will be used for all matches which
are at least two characters long and will use the code ‘3
’ for the
first character, ‘7
’ for the last character and ‘0
’ for the rest.
All three forms of name
may be preceded by a pattern in parentheses.
If this is given, the value
will be used only for matches in groups
whose names are matched by the pattern given in the parentheses. For
example, ‘(g*)m*=43
’ highlights all matches beginning with ‘m
’ in
groups whose names begin with ‘g
’ using the color code ‘43
’. In case
of the ‘lc
’, ‘rc
’, and ‘ec
’ codes, the group pattern is ignored.
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.
When printing a match, the code prints the value of lc
, the value for
the file-type or the last matching specification with a ‘*
’, the value
of rc
, the string to display for the match itself, and then the value
of ec
if that is defined or the values of lc
, no
, and rc
if ec
is not defined.
The default values are ISO 6429 (ANSI) compliant and can be used on
vt100 compatible terminals such as xterm
s. On monochrome terminals the
default values will have no visible effect. The colors
function from
the contribution can be used to get associative arrays containing the
codes for ANSI terminals (see Other
Functions). For example, after
loading colors
, one could use ‘$color[red]
’ to get the code for
foreground color red and ‘$color[bg-green]
’ for the code for
background color green.
If the completion system invoked by compinit is used, these parameters
should not be set directly because the system controls them itself.
Instead, the list-colors
style should be used (see Completion System
Configuration).
22.7.2 Scrolling in completion listings
To enable scrolling through a completion list, the LISTPROMPT
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 ‘%x
’. It supports the escapes ‘%B
’, ‘%b
’,
‘%S
’, ‘%s
’, ‘%U
’, ‘%u
’, ‘%F
’, ‘%f
’, ‘%K
’, ‘%k
’ and
‘%{``...``%}
’ used also in shell prompts as well as three pairs of
additional sequences: a ‘%l
’ or ‘%L
’ is replaced by the number of
the last line shown and the total number of lines in the form
‘number``/``total
’; a ‘%m
’ or ‘%M
’ is replaced with the number
of the last match shown and the total number of matches; and ‘%p
’ or
‘%P
’ is replaced with ‘Top
’, ‘Bottom
’ 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.
If the parameter LISTPROMPT
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
listscroll
keymap. Some of the zle functions have a special meaning
while scrolling lists:
-
send-break
stops listing discarding the key pressed -
accept-line
,down-history
,down-line-or-history
down-line-or-search
,vi-down-line-or-history
scrolls forward one line -
complete-word
,menu-complete
,expand-or-complete
expand-or-complete-prefix
,menu-complete-or-expand
scrolls forward one screenful -
accept-search
stop listing but take no other action
Every other character stops listing and immediately processes the key as
usual. Any key that is not bound in the listscroll
keymap or that is
bound to undefined-key
is looked up in the keymap currently selected.
As for the ZLS_COLORS
and ZLS_COLOURS
parameters, LISTPROMPT
should not be set directly when using the shell function based
completion system. Instead, the list-prompt
style should be used.
22.7.3 Menu selection
The zsh/complist
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 ALWAYS_LAST_PROMPT
option in
Options).
Menu selection can be invoked directly by the widget menu-select
defined by this module. This is a standard ZLE widget that can be bound
to a key in the usual way as described in Zsh Line
Editor.
Alternatively, the parameter MENUSELECT
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
menu-complete
, or due to one of the options MENU_COMPLETE
or
AUTO_MENU
being set. If MENUSELECT
is set, but is 0, 1 or empty,
menu selection will always be started during an ambiguous menu
completion.
When using the completion system based on shell functions, the
MENUSELECT
parameter should not be used (like the ZLS_COLORS
and
ZLS_COLOURS
parameters described above). Instead, the menu
style
should be used with the select=``...
keyword.
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 ma
from the ZLS_COLORS
or ZLS_COLOURS
parameter. The default value for
this is ‘7
’ which forces the selected match to be highlighted using
standout mode on a vt100-compatible terminal. If neither ZLS_COLORS
nor ZLS_COLOURS
is set, the same terminal control sequence as for the
‘%S
’ escape in prompts is used.
If there are more matches than fit on the screen and the parameter
MENUPROMPT
is set, its value will be shown below the matches. It
supports the same escape sequences as LISTPROMPT
, 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.
The MENUSCROLL
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 ‘0
’ (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.
As for the ZLS_COLORS
, ZLS_COLOURS
and LISTPROMPT
parameters,
neither MENUPROMPT
nor MENUSCROLL
should be set directly when using
the shell function based completion system. Instead, the select-prompt
and select-scroll
styles should be used.
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 -n
option of the compadd
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 hi
and du
capabilities in the
ZLS_COLORS
and ZLS_COLOURS
parameters are supported for hidden
matches of the first and second kind, respectively.
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:
-
accept-line
,accept-search
accept the current match and leave menu selection (but do not cause the command line to be accepted) -
send-break
leaves menu selection and restores the previous contents of the command line -
redisplay
,clear-screen
execute their normal function without leaving menu selection -
accept-and-hold
,accept-and-menu-complete
accept the currently inserted match and continue selection allowing to select the next match to insert into the line -
accept-and-infer-next-history
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 useundo
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) -
undo
removes matches inserted during the menu selection by one of the three functions before -
down-history
,down-line-or-history
vi-down-line-or-history
,down-line-or-search
moves the mark one line down -
up-history
,up-line-or-history
vi-up-line-or-history
,up-line-or-search
moves the mark one line up -
forward-char
,vi-forward-char
moves the mark one column right -
backward-char
,vi-backward-char
moves the mark one column left -
forward-word
,vi-forward-word
vi-forward-word-end
,emacs-forward-word
moves the mark one screenful down -
backward-word
,vi-backward-word
,emacs-backward-word
moves the mark one screenful up -
vi-forward-blank-word
,vi-forward-blank-word-end
moves the mark to the first line of the next group of matches -
vi-backward-blank-word
moves the mark to the last line of the previous group of matches -
beginning-of-history
moves the mark to the first line -
end-of-history
moves the mark to the last line -
beginning-of-buffer-or-history
,beginning-of-line
beginning-of-line-hist
,vi-beginning-of-line
moves the mark to the leftmost column -
end-of-buffer-or-history
,end-of-line
end-of-line-hist
,vi-end-of-line
moves the mark to the rightmost column -
complete-word
,menu-complete
,expand-or-complete
expand-or-complete-prefix
,menu-expand-or-complete
moves the mark to the next match -
reverse-menu-complete
moves the mark to the previous match -
vi-insert
this toggles between normal and interactive mode; in interactive mode the keys bound toself-insert
andself-insert-unmeta
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 andundo
andbackward-delete-char
go back to the previous set of matches -
history-incremental-search-forward
history-incremental-search-backward
this starts incremental searches in the list of completions displayed; in this mode,accept-line
only leaves incremental search, going back to the normal menu selection mode
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 ‘.
’ in front. For example, the widget
‘.accept-line
’ has the effect of leaving menu selection and
accepting the entire command line.
During this selection the widget uses the keymap menuselect
. Any key
that is not defined in this keymap or that is bound to undefined-key
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
menuselect
keymap can be modified directly using the bindkey
builtin
command (see The zsh/zle Module). For
example, to make the return key leave menu selection without accepting
the match currently selected one could call
bindkey -M menuselect '^M' send-break
after loading the zsh/complist
module.
22.8 The zsh/computil Module
The zsh/computil
module adds several builtin commands that are used by
some of the completion functions in the completion system based on shell
functions (see Completion
System ). Except for
compquote
these builtin commands are very specialised and thus not
very interesting when writing your own completion functions. In summary,
these builtin commands are:
comparguments
This is used by the _arguments
function to do the argument and command
line parsing. Like compdescribe
it has an option -i
to do the
parsing and initialize some internal state and various options to access
the state information to decide what should be completed.
compdescribe
This is used by the _describe
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 -i
or -I
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 _describe
itself.
Once compdescribe
has been called with either the -i
or the -I
option, it can be repeatedly called with the -g
option and the names
of four parameters as its arguments. This will step through the
different sets of matches and store the value of compstate[list]
in
the first scalar, the options for compadd
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 compadd
to register the matches with the completion code.
compfiles
Used by the _path_files
function to optimize complex recursive
filename generation (globbing). It does three things. With the -p
and
-P
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 -i
option does the directory tests for the ignore-parents
style and the -r
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.
compgroups
Used by the _tags
function to implement the internals of the
group-order
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).
compquote
[ -p
] names
...
There may be reasons to write completion functions that have to add the
matches using the -Q
option to compadd
and perform quoting
themselves. Instead of interpreting the first character of the
all_quotes
key of the compstate
special association and using the
q
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 -p
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.
The return status is non-zero in case of an error and zero otherwise.
comptags
comptry
These implement the internals of the tags mechanism.
compvalues
Like comparguments
, but for the _values
function.
22.9 The zsh/curses Module
The zsh/curses
module makes available one builtin command and various
parameters.
22.9.1 Builtin
zcurses
init
zcurses
end
zcurses
addwin
targetwin
nlines
ncols
begin_y
begin_x
[
parentwin
]
zcurses
delwin
targetwin
zcurses
refresh
[ targetwin
... ]
zcurses
touch
targetwin
...
zcurses
move
targetwin
new_y
new_x
zcurses
clear
targetwin
[ redraw
| eol
| bot
]
zcurses
position
targetwin
array
zcurses
char
targetwin
character
zcurses
string
targetwin
string
zcurses
border
targetwin
border
zcurses
attr
targetwin
[ [+
|-
]attribute
|
fg_col``/``bg_col
] [...]
zcurses
bg
targetwin
[ [+
|-
]attribute
|
fg_col``/``bg_col
| @``char
] [...]
zcurses
scroll
targetwin
[ on
| off
| [+
|-
]lines
]
zcurses
input
targetwin
[ param
[ kparam
[ mparam
] ]
]
zcurses
mouse
[ delay
num
| [+
|-
]motion
]
zcurses
timeout
targetwin
intval
zcurses
querychar
targetwin
[ param
]
zcurses
resize
height
width
[ endwin
| nosave
|
endwin_nosave
]
Manipulate curses windows. All uses of this command should be bracketed
by ‘zcurses init
’ to initialise use of curses, and ‘zcurses end
’ to
end it; omitting ‘zcurses end
’ can cause the terminal to be in an
unwanted state.
The subcommand addwin
creates a window with nlines
lines and ncols
columns. Its upper left corner will be placed at row begin_y
and
column begin_x
of the screen. targetwin
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.
If addwin
is given an existing window as the final argument, the new
window is created as a subwindow of parentwin
. 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.
Use the subcommand delwin
to delete a window created with addwin
.
Note that end
does not implicitly delete windows, and that delwin
does not erase the screen image of the window.
The window corresponding to the full visible screen is called stdscr
;
it always exists after ‘zcurses init
’ and cannot be delete with
delwin
.
The subcommand refresh
will refresh window targetwin
; this is
necessary to make any pending changes (such as characters you have
prepared for output with char
) visible on the screen. refresh
without an argument causes the screen to be cleared and redrawn. If
multiple windows are given, the screen is updated once at the end.
The subcommand touch
marks the targetwin
s listed as changed. This is
necessary before refresh
ing windows if a window that was in front of
another window (which may be stdscr
) is deleted.
The subcommand move
moves the cursor position in targetwin
to new
coordinates new_y
and new_x
. Note that the subcommand string
(but
not the subcommand char
) advances the cursor position over the
characters added.
The subcommand clear
erases the contents of targetwin
. One (and no
more than one) of three options may be specified. With the option
redraw
, in addition the next refresh
of targetwin
will cause the
screen to be cleared and repainted. With the option eol
, targetwin
is only cleared to the end of the current cursor line. With the option
bot
, targetwin
is cleared to the end of the window, i.e everything
to the right and below the cursor is cleared.
The subcommand position
writes various positions associated with
targetwin
into the array named array
. These are, in order:
-
-
The y and x coordinates of the cursor relative to the top left oftargetwin
-
-
The y and x coordinates of the top left oftargetwin
on the screen -
-
The size oftargetwin
in y and x dimensions.
Outputting characters and strings are achieved by char
and string
respectively.
To draw a border around window targetwin
, use border
. 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.
The subcommand attr
will set targetwin
’s attributes or
foreground/background color pair for any successive character output.
Each attribute
given on the line may be prepended by a +
to set or a
-
to unset that attribute; +
is assumed if absent. The attributes
supported are blink
, bold
, dim
, reverse
, standout
, and
underline
.
Each fg_col``/``bg_col
attribute (to be read as ‘fg_col
on
bg_col
’) sets the foreground and background color for character
output. The color default
is sometimes available (in particular if the
library is ncurses), specifying the foreground or background color with
which the terminal started. The color pair default/default
is always
available. To use more than the 8 named colors (red, green, etc.)
construct the fg_col``/``bg_col
pairs where fg_col
and bg_col
are
decimal integers, e.g 128/200
. The maximum color value is 254 if the
terminal supports 256 colors.
bg
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 attr
, an argument
@``char
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.
The subcommand scroll
can be used with on
or off
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 off
it is temporarily turned on
to
allow the window to be scrolled.
The subcommand input
reads a single character from the window without
echoing it back. If param
is supplied the character is assigned to the
parameter param
, else it is assigned to the parameter REPLY
.
If both param
and kparam
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 kparam
. The key names are
the macros defined in the curses.h
or ncurses.h
with the prefix
‘KEY_
’ removed; see also the description of the parameter
zcurses_keycodes
below. Other keys cause a value to be set in param
as before. On a successful return only one of param
or kparam
contains a non-empty string; the other is set to an empty string.
If mparam
is also supplied, input
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 ‘zcurses mouse
’ 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 kparam
is set to the string MOUSE
, and mparam
is set to an
array consisting of the following elements:
-
-
An identifier to discriminate different input devices; this is only rarely useful. -
-
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. -
-
Any events that occurred as separate items; usually there will be just one. An event consists ofPRESSED
,RELEASED
,CLICKED
,DOUBLE_CLICKED
orTRIPLE_CLICKED
followed immediately (in the same element) by the number of the button. -
-
If the shift key was pressed, the stringSHIFT
. -
-
If the control key was pressed, the stringCTRL
. -
-
If the alt key was pressed, the stringALT
.
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.
The subcommand mouse
can be used to configure the use of the mouse.
There is no window argument; mouse options are global. ‘zcurses mouse
’
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. delay
num
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. motion
proceeded by an optional ‘+
’ (the
default) or -
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.
The subcommand timeout
specifies a timeout value for input from
targetwin
. If intval
is negative, ‘zcurses input
’ waits
indefinitely for a character to be typed; this is the default. If
intval
is zero, ‘zcurses input
’ returns immediately; if there is
typeahead it is returned, else no input is done and status 1 is
returned. If intval
is positive, ‘zcurses input
’ waits intval
milliseconds for input and if there is none at the end of that period
returns status 1.
The subcommand querychar
queries the character at the current cursor
position. The return values are stored in the array named param
if
supplied, else in the array reply
. 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 fg_col``/``bg_col
notation, or
0
if color is not supported. Any attributes other than color that
apply to the character, as set with the subcommand attr
, appear as
additional elements.
The subcommand resize
resizes stdscr
and all windows to given
dimensions (windows that stick out from the new dimensions are resized
down). The underlying curses extension (resize_term call
) can be
unavailable. To verify, zeroes can be used for height
and width
. If
the result of the subcommand is 0
, resize_term is available (2
otherwise). Tests show that resizing can be normally accomplished by
calling zcurses end
and zcurses refresh
. The resize
subcommand is
provided for versatility. Multiple system configurations have been
checked and zcurses end
and zcurses refresh
are still needed for
correct terminal state after resize. To invoke them with resize
, use
endwin
argument. Using nosave
argument will cause new terminal state
to not be saved internally by zcurses
. This is also provided for
versatility and should normally be not needed.
22.9.2 Parameters
ZCURSES_COLORS
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 zcurses init
is run.
ZCURSES_COLOR_PAIRS
Readonly integer. The maximum number of color pairs fg_col``/``bg_col
that may be defined in ‘zcurses attr
’ 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 zcurses init
is run.
zcurses_attrs
Readonly array. The attributes supported by zsh/curses
; available as
soon as the module is loaded.
zcurses_colors
Readonly array. The colors supported by zsh/curses
; available as soon
as the module is loaded.
zcurses_keycodes
Readonly array. The values that may be returned in the second parameter
supplied to ‘zcurses input
’ in the order in which they are defined
internally by curses. Not all function keys are listed, only F0
;
curses reserves space for F0
up to F63
.
zcurses_windows
Readonly array. The current list of windows, i.e. all windows that have
been created with ‘zcurses addwin
’ and not removed with ‘zcurses delwin
’.
22.10 The zsh/datetime Module
The zsh/datetime
module makes available one builtin command:
strftime
[ -s
scalar
] format
[ epochtime
[ nanoseconds
] ]
strftime
-r
[ -q
] [ -s
scalar
] format
timestring
Output the date in the format
specified. With no epochtime
, the
current system date/time is used; optionally, epochtime
may be used to
specify the number of seconds since the epoch, and nanoseconds
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 Prompt
Expansion are also available.
-
-q
Run quietly; suppress printing of all error messages described below. Errors for invalidepochtime
values are always printed. -
-r
With the option-r
(reverse), useformat
to parse the input stringtimestring
and output the number of seconds since the epoch at which the time occurred. The parsing is implemented by the system functionstrptime
; see man page strptime(3). This means that zsh format extensions are not available, but for reverse lookup they are not required.In most implementations of
strftime
any timezone in thetimestring
is ignored and the local timezone declared by theTZ
environment variable is used; other parameters are set to zero if not present.If
timestring
does not matchformat
the command returns status 1 and prints an error message. Iftimestring
matchesformat
but not all characters intimestring
were used, the conversion succeeds but also prints an error message.If either of the system functions
strptime
ormktime
is not available, status 2 is returned and an error message is printed. -
-s
scalar
Assign the date string (or epoch time in seconds if-r
is given) toscalar
instead of printing it.
Note that depending on the system’s declared integral time type,
strftime
may produce incorrect results for epoch times greater than
2147483647 which corresponds to 2038-01-19 03:14:07 +0000.
The zsh/datetime
module makes available several parameters; all are
readonly:
EPOCHREALTIME
A floating point value representing the number of seconds since the
epoch. The notional accuracy is to nanoseconds if the clock_gettime
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.
EPOCHSECONDS
An integer value representing the number of seconds since the epoch.
epochtime
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:
for secs nsecs in $epochtime; do
...
done
22.11 The zsh/db/gdbm Module
The zsh/db/gdbm
module is used to create "tied" 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 ztie
builtin may move to a more generic
module in the future.
The builtins in this module are:
ztie -d db/gdbm -f
filename
[ -r
] arrayname
Open the GDBM database identified by filename
and, if successful,
create the associative array arrayname
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:
local -A sampledb
ztie -d db/gdbm -f sample.gdbm sampledb
The -r
option opens the database file for reading only, creating a
parameter with the readonly attribute. Without this option, using
‘ztie
’ on a file for which the user does not have write permission
is changed in arrayname
are immediately written to filename
.
Changes to the file modes filename
after it has been opened do not
alter the state of arrayname
, but ‘typeset -r
arrayname
’ works as
expected.
zuntie
[ -u
] arrayname
...
Close the GDBM database associated with each arrayname
and then unset
the parameter. The -u
option forces an unset of parameters made
readonly with ‘ztie -r
’.
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 ‘ztie -r
’ is to use ‘zuntie -u
’.
zgdbmpath
parametername
Put path to database file assigned to parametername
into REPLY
scalar.
zgdbm_tied
Array holding names of all tied parameters.
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.
22.12 The zsh/deltochar Module
The zsh/deltochar
module makes available two ZLE functions:
delete-to-char
Read a character from the keyboard, and delete from the cursor position
up to and including the next (or, with repeat count n
, the n
th)
instance of that character. Negative repeat counts mean delete
backwards.
zap-to-char
This behaves like delete-to-char
, except that the final occurrence of
the character itself is not deleted.
22.13 The zsh/example Module
The zsh/example
module makes available one builtin command:
example
[ -flags
] [ args
... ]
Displays the flags and arguments it is invoked with.
The purpose of the module is to serve as an example of how to write a module.
22.14 The zsh/files Module
The zsh/files
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.
For all commands, a variant beginning zf_
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:
zmodload -m -F zsh/files b:zf_\*
The commands loaded by default are:
chgrp
[ -hRs
] group
filename
...
Changes group of files specified. This is equivalent to chown
with a
user-spec
argument of ‘:``group
’.
chmod
[ -Rs
] mode
filename
...
Changes mode of files specified.
The specified mode
must be in octal.
The -R
option causes chmod
to recursively descend into directories,
changing the mode of all files in the directory after changing the mode
of the directory itself.
The -s
option is a zsh extension to chmod
functionality. It enables
paranoid behaviour, intended to avoid security problems involving a
chmod
being tricked into affecting files other than the ones intended.
It will refuse to follow symbolic links, so that (for example)
‘‘chmod 600 /tmp/foo/passwd
’’ can’t accidentally chmod
/etc/passwd
if /tmp/foo
happens to be a link to /etc
. 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 /usr
as a
result of directories being moved up the tree.
chown
[ -hRs
] user-spec
filename
...
Changes ownership and group of files specified.
The user-spec
can be in four forms:
-
user
change owner touser
; do not change group -
user``::
change owner touser
; do not change group -
user``:
change owner touser
; change group touser
’s primary group -
user``:``group
change owner touser
; change group togroup
-
:``group
do not change owner; change group togroup
In each case, the ‘:
’ may instead be a ‘.
’. The rule is that if
there is a ‘:
’ then the separator is ‘:
’, otherwise if there is a
‘.
’ then the separator is ‘.
’, otherwise there is no separator.
Each of user
and group
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).
If the target is a symbolic link, the -h
option causes chown
to set
the ownership of the link instead of its target.
The -R
option causes chown
to recursively descend into directories,
changing the ownership of all files in the directory after changing the
ownership of the directory itself.
The -s
option is a zsh extension to chown
functionality. It enables
paranoid behaviour, intended to avoid security problems involving a
chown
being tricked into affecting files other than the ones intended.
It will refuse to follow symbolic links, so that (for example) ‘‘chown luser /tmp/foo/passwd
’’ can’t accidentally chown /etc/passwd
if
/tmp/foo
happens to be a link to /etc
. 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 /usr
as a result of
directories being moved up the tree.
ln
[ -dfhins
] filename
dest
ln
[ -dfhins
] filename
... dir
Creates hard (or, with -s
, symbolic) links. In the first form, the
specified dest
ination is created, as a link to the specified
filename
. In the second form, each of the filename
s is taken in
turn, and linked to a pathname in the specified dir
ectory that has the
same last pathname component.
Normally, ln
will not attempt to create hard links to directories.
This check can be overridden using the -d
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.
By default, existing files cannot be replaced by links. The -i
option
causes the user to be queried about replacing existing files. The -f
option causes existing files to be silently deleted, without querying.
-f
takes precedence.
The -h
and -n
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 -sf
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.
mkdir
[ -p
] [ -m
mode
] dir
...
Creates directories. With the -p
option, non-existing parent
directories are first created if necessary, and there will be no
complaint if the directory already exists. The -m
option can be used
to specify (in octal) a set of file permissions for the created
directories, otherwise mode 777 modified by the current umask
(see man
page umask(2)) is used.
mv
[ -fi
] filename
dest
mv
[ -fi
] filename
... dir
Moves files. In the first form, the specified filename
is moved to the
specified dest
ination. In the second form, each of the filename
s is
taken in turn, and moved to a pathname in the specified dir
ectory that
has the same last pathname component.
By default, the user will be queried before replacing any file removed.
The -i
option causes the user to be queried about replacing any
existing files. The -f
option causes any existing files to be silently
deleted, without querying. -f
takes precedence.
Note that this mv
will not move files across devices. Historical
versions of mv
, when actual renaming is impossible, fall back on
copying and removing files; if this behaviour is desired, use cp
and
rm
manually. This may change in a future version.
rm
[ -dfiRrs
] filename
...
Removes files and directories specified.
Normally, rm
will not remove directories (except with the -R
or -r
options). The -d
option causes rm
to try removing directories with
unlink
(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. -d
takes precedence over -R
and -r
.
By default, the user will be queried before removing any file removed.
The -i
option causes the user to be queried about removing any files.
The -f
option causes files to be silently deleted, without querying,
and suppresses all error indications. -f
takes precedence.
The -R
and -r
options cause rm
to recursively descend into
directories, deleting all files in the directory before removing the
directory with the rmdir
system call (see man page rmdir(2)).
The -s
option is a zsh extension to rm
functionality. It enables
paranoid behaviour, intended to avoid common security problems involving
a root-run rm
being tricked into removing files other than the ones
intended. It will refuse to follow symbolic links, so that (for example)
‘‘rm /tmp/foo/passwd
’’ can’t accidentally remove /etc/passwd
if
/tmp/foo
happens to be a link to /etc
. 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 /usr
as a result of
directories being moved up the tree.
rmdir
dir
...
Removes empty directories specified.
sync
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.
22.15 The zsh/langinfo Module
The zsh/langinfo
module makes available one parameter:
langinfo
An associative array that maps langinfo elements to their values.
Your implementation may support a number of the following keys:
CODESET
, D_T_FMT
, D_FMT
, T_FMT
, RADIXCHAR
, THOUSEP
,
YESEXPR
, NOEXPR
, CRNCYSTR
, ABDAY_{1..7}
, DAY_{1..7}
,
ABMON_{1..12}
, MON_{1..12}
, T_FMT_AMPM
, AM_STR
, PM_STR
, ERA
,
ERA_D_FMT
, ERA_D_T_FMT
, ERA_T_FMT
, ALT_DIGITS
22.16 The zsh/mapfile Module
The zsh/mapfile
module provides one special associative array
parameter of the same name.
mapfile
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, ‘vared mapfile[myfile]
’ works as
expected, editing the file ‘myfile
’.
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 ${(k)mapfile}
has the same effect as the
glob operator *(D)
, since files beginning with a dot are not special.
Care must be taken with expressions such as rm ${(k)mapfile}
, which
will delete every file in the current directory without the usual ‘rm *
’ test.
The parameter mapfile
may be made read-only; in that case, files
referenced may not be written or deleted.
A file may conveniently be read into an array as one line per element
with the form ‘array``=("${(f@)mapfile[``filename``]}")
’. The double
quotes and the ‘@
’ 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
‘array``=("${(f@)${mapfile[``filename``]%$’\n’}}")
’.
22.16.1 Limitations
Although reading and writing of the file in question is efficiently
handled, zsh’s internal memory management may be arbitrarily baroque;
however, mapfile
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.
No errors are printed or flagged for non-existent, unreadable, or execution hierarchy to make this convenient.
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.
22.17 The zsh/mathfunc Module
The zsh/mathfunc
module provides standard mathematical functions for
use when evaluating mathematical formulae. The syntax agrees with normal
C and FORTRAN conventions, for example,
(( f = sin(0.3) ))
assigns the sine of 0.3 to the parameter f.
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 atan
with a second
argument and the abs
, int
and float
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.
The following functions take a single floating point argument: acos
,
acosh
, asin
, asinh
, atan
, atanh
, cbrt
, ceil
, cos
,
cosh
, erf
, erfc
, exp
, expm1
, fabs
, floor
, gamma
, j0
,
j1
, lgamma
, log
, log10
, log1p
, log2
, logb
, sin
, sinh
,
sqrt
, tan
, tanh
, y0
, y1
. The atan
function can optionally
take a second argument, in which case it behaves like the C function
atan2
. The ilogb
function takes a single floating point argument,
but returns an integer.
The function signgam
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
gamma
or lgamma
. Note also that ‘signgam()
’ and ‘signgam
’ are
distinct expressions.
The functions min
, max
, and sum
are defined not in this module but
in the zmathfunc
autoloadable function, described in Mathematical
Functions.
The following functions take two floating point arguments: copysign
,
fmod
, hypot
, nextafter
.
The following take an integer first argument and a floating point second
argument: jn
, yn
.
The following take a floating point first argument and an integer second
argument: ldexp
, scalb
.
The function abs
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 float
and int
convert their arguments into a
floating point or integer value (by truncation) respectively.
Note that the C pow
function is available in ordinary math evaluation
as the ‘**
’ operator and is not provided here.
The function rand48
is available if your system’s mathematical library
has the function erand48(3)
. It returns a pseudo-random floating point
number between 0 and 1. It takes a single string optional argument.
If the argument is not present, the random number seed is initialised by
three calls to the rand(3)
function — this produces the same random
numbers as the next three values of $RANDOM
.
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 rand48
with no argument. Subsequent calls to
rand48
(param
) will then maintain the seed in the parameter param
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
rand48
with no argument.
For example, consider
print $(( rand48(seed) ))
print $(( rand48() ))
print $(( rand48(seed) ))
Assuming $seed
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 rand()
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 rand48()
.
22.18 The zsh/nearcolor Module
The zsh/nearcolor
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.
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
In order to use the zsh/nearcolor
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
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 zsh/nearcolor
module. For example, the following checks
the COLORTERM
environment variable:
[[ $COLORTERM = *(24bit|truecolor)* ]] || zmodload zsh/nearcolor
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
zsh/nearcolor
module.
22.19 The zsh/newuser Module
The zsh/newuser
module is loaded at boot if it is available, the RCS
option is set, and the PRIVILEGED
option is not set (all three are
true by default). This takes place immediately after commands in the
global zshenv
file (typically /etc/zshenv
), 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 $MODULE_PATH
by the
administrator if it is not required.
On loading, the module tests if any of the start-up files .zshenv
,
.zprofile
, .zshrc
or .zlogin
exist in the directory given by the
environment variable ZDOTDIR
, or the user’s home directory if that is
not set. The test is not performed and the module halts processing if
the shell was in an emulation mode (i.e. had been invoked as some other
shell than zsh).
If none of the start-up files were found, the module then looks for the
file newuser
first in a sitewide directory, usually the parent
directory of the site-functions
directory, and if that is not found
the module searches in a version-specific directory, usually the parent
of the functions
directory containing version-specific functions.
(These directories can be configured when zsh is built using the
–enable-site-scriptdir=``dir
and –enable-scriptdir=``dir
flags to
configure
, respectively; the defaults are prefix``/share/zsh
and
prefix``/share/zsh/$ZSH_VERSION
where the default prefix
is
/usr/local
.)
If the file newuser
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.
The zsh/newuser
module is then unconditionally unloaded.
Note that it is possible to achieve exactly the same effect as the
zsh/newuser
module by adding code to /etc/zshenv
. 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.
The script supplied with the module invokes the shell function
zsh-newuser-install
. This may be invoked directly by the user even if
the zsh/newuser
module is disabled. Note, however, that if the module
is not installed the function will not be installed either. The function
is documented in User Configuration
Functions.
22.20 The zsh/parameter Module
The zsh/parameter
module gives access to some of the internal hash
options
The keys for this associative array are the names of the options that
can be set and unset using the setopt
and unsetopt
builtins. The
value of each key is either the string on
if the option is currently
set, or the string off
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 off
.
commands
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 hash
builtin. Unsetting a key as in ‘unset "commands[foo]"
’
removes the entry for the given key from the command
functions
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.
dis_functions
Like functions
but for disabled functions.
functions_source
This readonly associative array maps names of enabled functions to the name of the file containing the source of the function.
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
‘functions -r
’, this is the file found for autoloading, resolved to
an absolute path.
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.
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 $functions
.
dis_functions_source
Like functions_source
but for disabled functions.
builtins
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 ‘undefined
’ for builtin commands that will
automatically be loaded from a module if invoked or ‘defined
’ for
builtin commands that are already loaded.
dis_builtins
Like builtins
but for disabled builtin commands.
reswords
This array contains the enabled reserved words.
dis_reswords
Like reswords
but for disabled reserved words.
patchars
This array contains the enabled pattern characters.
dis_patchars
Like patchars
but for disabled pattern characters.
aliases
This maps the names of the regular aliases currently enabled to their expansions.
dis_aliases
Like aliases
but for disabled regular aliases.
galiases
Like aliases
, but for global aliases.
dis_galiases
Like galiases
but for disabled global aliases.
saliases
Like raliases
, but for suffix aliases.
dis_saliases
Like saliases
but for disabled suffix aliases.
parameters
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 t
parameter flag, see
Parameter Expansion . Setting or
unsetting keys in this array is not possible.
modules
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 ‘loaded
’, ‘autoloaded
’, or ‘alias:``name
’, where name
is
the name the module is aliased to.
Setting or unsetting keys in this array is not possible.
dirstack
A normal array holding the elements of the directory stack. Note that
the output of the dirs
builtin command includes one more directory,
the current working directory.
history
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 (${history[@]}
) is guaranteed to be returned in order from
most recent to oldest history event, that is, by decreasing history
event number.
historywords
A special array containing the words stored in the history. These also appear in most to least recent order.
jobdirs
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).
The keys of the associative arrays are usually valid job numbers, and
these are the values output with, for example, ${(k)jobdirs}
.
Non-numeric job references may be used when looking up a value; for
example, ${jobdirs[%+]}
refers to the current job.
jobtexts
This associative array maps job numbers to the texts of the command lines that were used to start the jobs.
Handling of the keys of the associative array is as described for
jobdirs
above.
jobstates
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 ‘job-state``:``mark``:``pid``=``state
...’. The job-state
gives the state the whole job is currently in, one of ‘running
’,
‘suspended
’, or ‘done
’. The mark
is ‘+
’ for the current job,
‘-
’ for the previous job and empty otherwise. This is followed by
one ‘:``pid``=``state
’ for every process in the job. The pid
s are,
of course, the process IDs and the state
describes the state of that
process.
Handling of the keys of the associative array is as described for
jobdirs
above.
nameddirs
This associative array maps the names of named directories to the pathnames they stand for.
userdirs
This associative array maps user names to the pathnames of their home directories.
usergroups
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 id
command.
funcfiletrace
This array contains the absolute line numbers and corresponding file
names for the point where the current function, sourced file, or (if
EVAL_LINENO
is set) eval
command was called. The array is of the
same length as funcsourcetrace
and functrace
, but differs from
funcsourcetrace
in that the line and file are the point of call, not
the point of definition, and differs from functrace
in that all values
are absolute line numbers in files, rather than relative to the start of
a function, if any.
funcsourcetrace
This array contains the file names and line numbers of the points where
the functions, sourced files, and (if EVAL_LINENO
is set) eval
commands currently being executed were defined. The line number is the
line where the ‘function
name
’ or ‘name
()
’ started. In the case
of an autoloaded function the line number is reported as zero. The
format of each element is filename``:``lineno
.
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 source
or ‘.
’ builtins, the trace information is
shown as filename``:``0
, 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.
Most users will be interested in the information in the funcfiletrace
array instead.
funcstack
This array contains the names of the functions, sourced files, and (if
EVAL_LINENO
is set) eval
commands. currently being executed. The
first element is the name of the function using the parameter.
The standard shell array zsh_eval_context
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 toplevel
, the main
shell code being executed either interactively or from a script, which
is not present in $funcstack
.
functrace
This array contains the names and line numbers of the callers
corresponding to the functions currently being executed. The format of
each element is name``:``lineno
. Callers are also shown for sourced
files; the caller is the point where the source
or ‘.
’ command was
executed.
22.21 The zsh/pcre Module
The zsh/pcre
module makes some commands available as builtins:
pcre_compile
[ -aimxs
] PCRE
Compiles a perl-compatible regular expression.
Option -a
will force the pattern to be anchored. Option -i
will
compile a case-insensitive pattern. Option -m
will compile a
multi-line pattern; that is, ^
and $
will match newlines within the
pattern. Option -x
will compile an extended pattern, wherein
whitespace and #
comments are ignored. Option -s
makes the dot
metacharacter match all characters, including those that indicate
newline.
pcre_study
Studies the previously-compiled PCRE which may result in faster matching.
pcre_match
[ -v
var
] [ -a
arr
] [ -n
offset
] [
-b
] string
Returns successfully if string
matches the previously-compiled PCRE.
Upon successful match, if the expression captures substrings within
parentheses, pcre_match
will set the array match
to those
substrings, unless the -a
option is given, in which case it will set
the array arr
. Similarly, the variable MATCH
will be set to the
entire matched portion of the string, unless the -v
option is given,
in which case the variable var
will be set. No variables are altered
if there is no successful match. A -n
option starts searching for a
match from the byte offset
position in string
. If the -b
option is
given, the variable ZPCRE_OP
will be set to an offset pair string,
representing the byte offset positions of the entire matched portion
within the string
. For example, a ZPCRE_OP
set to "32 45" 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 string
,
using an offset position as an argument to the -n
option. This is
mostly used to implement the "find all non-overlapping matches"
functionality.
A simple example of "find all non-overlapping matches":
string="The following zip codes: 78884 90210 99513"
pcre_compile -m "\d{5}"
accum=()
pcre_match -b -- $string
while [[ $? -eq 0 ]] do
b=($=ZPCRE_OP)
accum+=$MATCH
pcre_match -b -n $b[2] -- $string
done
print -l $accum
The zsh/pcre
module makes available the following test condition:
expr
-pcre-match
pcre
Matches a string against a perl-compatible regular expression.
For example,
[[ "$text" -pcre-match ^d+$ ]] &&
print text variable contains only "d's".
If the REMATCH_PCRE
option is set, the =~
operator is equivalent to
-pcre-match
, and the NO_CASE_MATCH
option may be used. Note that
NO_CASE_MATCH
never applies to the pcre_match
builtin, instead use
the -i
switch of pcre_compile
.
22.22 The zsh/param/private Module
The zsh/param/private
module is used to create parameters whose scope
is limited to the current function body, and not to other functions
called by the current function.
This module provides a single autoloaded builtin:
private
[ {+
|-
}AHUahlprtux
] [ {+
|-
}EFLRZi
[ n
] ]
[ name
[=``value
] ... ]
The private
builtin accepts all the same options and arguments as
local
(Shell Builtin
Commands) except
for the ‘-``T
’ option. Tied parameters may not be made private.
If used at the top level (outside a function scope), private
creates a
normal parameter in the same manner as declare
or typeset
. A warning
about this is printed if WARN_CREATE_GLOBAL
is set
(Options). Used inside a function scope,
private
creates a local parameter similar to one declared with
local
, except having special properties noted below.
Special parameters which expose or manipulate internal shell state, such
as ARGC
, argv
, COLUMNS
, LINES
, UID
, EUID
, IFS
, PROMPT
,
RANDOM
, SECONDS
, etc., cannot be made private unless the ‘-``h
’
option is used to hide the special meaning of the parameter. This may
change in the future.
As with other typeset
equivalents, private
is both a builtin and a
reserved word, so arrays may be assigned with parenthesized word list
name``=(``value
...)
syntax. However, the reserved word ‘private
’
is not available until zsh/param/private
is loaded, so care must be
taken with order of execution and parsing for function definitions which
use private
. To compensate for this, the module also adds the option
‘-P
’ to the ‘local
’ builtin to declare private parameters.
For example, this construction fails if zsh/param/private
has not yet
been loaded when ‘bad_declaration
’ is defined:
bad_declaration() {
zmodload zsh/param/private
private array=( one two three )
}
This construction works because local
is already a keyword, and the
module is loaded before the statement is executed:
good_declaration() {
zmodload zsh/param/private
local -P array=( one two three )
}
The following is usable in scripts but may have trouble with autoload
:
zmodload zsh/param/private
iffy_declaration() {
private array=( one two three )
}
The private
builtin may always be used with scalar assignments and for
declarations without assignments.
Parameters declared with private
have the following properties:
- Within the function body where it is declared, the parameter behaves as a local, except as noted above for tied or special parameters.
- 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.
- Within any other function called by the declaring function, the private parameter does NOT 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.
- 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.
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
‘typeset -S
’ because the syntax used to define the function has no
bearing on whether the parameter scope is respected.
22.23 The zsh/regex Module
The zsh/regex
module makes available the following test condition:
expr
-regex-match
regex
Matches a string against a POSIX extended regular expression. On
successful match, matched portion of the string will normally be placed
in the MATCH
variable. If there are any capturing parentheses within
the regex, then the match
array variable will contain those. If the
match is not successful, then the variables will not be altered.
For example,
[[ alphabetical -regex-match ^a([^a]+)a([^a]+)a ]] &&
print -l $MATCH X $match
If the option REMATCH_PCRE
is not set, then the =~
operator will
automatically load this module as needed and will invoke the
-regex-match
operator.
If BASH_REMATCH
is set, then the array BASH_REMATCH
will be set
instead of MATCH
and match
.
22.24 The zsh/sched Module
The zsh/sched
module makes available one builtin command and one
parameter.
sched
[-o
] [+
]hh``:``mm
[:``ss
] command
...
sched
[-o
] [+
]seconds
command
...
sched
[ -``item
]
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 zsh/datetime
module, see The zsh/datetime
Module.
With no arguments, prints the list of scheduled commands. If the
scheduled command has the -o
flag set, this is shown at the start of
the command.
With the argument ‘-``item
’, 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.
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 -o
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.
To effect changes to the editor buffer when an event executes, use the
‘zle
’ command with no arguments to test whether the editor is
active, and if it is, then use ‘ zle ``widget
’ to access the editor
via the named widget
.
The sched
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 ‘zmodload -F zsh/sched b:sched
’.
zsh_scheduled_events
A readonly array corresponding to the events scheduled by the sched
builtin. The indices of the array correspond to the numbers shown when
sched
is run with no arguments (provided that the KSH_ARRAYS
option
is not set). The value of the array consists of the scheduled time in
seconds since the epoch (see The zsh/datetime
Module for facilities for using this
number), followed by a colon, followed by any options (which may be
empty but will be preceded by a ‘-
’ otherwise), followed by a colon,
followed by the command to be executed.
The sched
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.
22.25 The zsh/net/socket Module
The zsh/net/socket
module makes available one builtin command:
zsocket
[ -altv
] [ -d
fd
] [ args
]
zsocket
is implemented as a builtin to allow full use of shell command
line editing, file I/O, and job control mechanisms.
22.25.1 Outbound Connections
-
zsocket
[-v
] [-d
fd
]filename
Open a new Unix domain connection tofilename
. The shell parameterREPLY
will be set to the file descriptor associated with that connection. Currently, only stream connections are supported.If
-d
is specified, its argument will be taken as the target file descriptor for the connection.In order to elicit more verbose output, use
-v
.File descriptors can be closed with normal shell syntax when no longer needed, for example:
exec {REPLY}>&-
22.25.2 Inbound Connections
-
zsocket
-l
[-v
] [-d
fd
]filename
zsocket -l
will open a socket listening onfilename
. The shell parameterREPLY
will be set to the file descriptor associated with that listener. The file descriptor remains open in subshellsIf
-d
is specified, its argument will be taken as the target file descriptor for the connection.In order to elicit more verbose output, use
-v
. -
zsocket
-a
[-tv
] [-d
targetfd
]listenfd
zsocket -a
will accept an incoming connection to the socket associated withlistenfd
. The shell parameterREPLY
will be set to the file descriptor associated with the inbound connection. The file descriptor remains open in subshellsIf
-d
is specified, its argument will be taken as the target file descriptor for the connection.If
-t
is specified,zsocket
will return if no incoming connection is pending. Otherwise it will wait for one.In order to elicit more verbose output, use
-v
.
22.26 The zsh/stat Module
The zsh/stat
module makes available one builtin command under two
possible names:
zstat
[ -gnNolLtTrs
] [ -f
fd
] [ -H
hash
] [ -A
array
] [ -F
fmt
]
[ +``element
] [ file
... ]
stat
...
The command acts as a front end to the stat
system call (see man page
stat(2)). The same command is provided with two names; as the name
stat
is often used by an external command it is recommended that only
the zstat
form of the command is used. This can be arranged by loading
the module with the command ‘zmodload -F zsh/stat b:zstat
’.
If the stat
call fails, the appropriate system error message printed
and status 1 is returned. The fields of struct stat
give information
about the files provided as arguments to the command. In addition to
those available from the stat
call, an extra element ‘link
’ is
provided. These elements are:
-
device
The number of the device on which the file resides. -
inode
The unique number of the file on this device (‘inode’ number). -
mode
The mode of the file; that is, the file’s type and access permissions. With the-s
option, this will be returned as a string corresponding to the first column in the display of thels -l
command. -
nlink
The number of hard links to the file. -
uid
The user ID of the owner of the file. With the-s
option, this is displayed as a user name. -
gid
The group ID of the file. With the-s
option, this is displayed as a group name. -
rdev
The raw device number. This is only useful for special devices. -
size
The size of the file in bytes. -
atime
mtime
ctime
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-s
option, these are printed as strings for the local time zone; the format can be altered with the-F
option, and with the-g
option the times are in GMT. -
blksize
The number of bytes in one allocation block on the device on which the file resides. -
block
The number of disk blocks used by the file. -
link
If the file is a link and the-L
option is in effect, this contains the name of the file linked to, otherwise it is empty. Note that if this element is selected (‘‘zstat +link
’’) then the-L
option is automatically used.
A particular element may be selected by including its name preceded by a
‘+
’ 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.
Options:
-
-A
array
Instead of displaying the results on standard output, assign them to anarray
, onestruct stat
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 inarray
unless the-t
or-n
options were given, respectively. If-t
is given, the element name appears as a prefix to the appropriate array element; if-n
is given, the file name appears as a separate array element preceding all the others. Other formatting options are respected. -
-H
hash
Similar to-A
, but instead assign the values tohash
. The keys are the elements listed above. If the-n
option is provided then the name of the file is included in the hash with keyname
. -
-f
fd
Use the file on file descriptorfd
instead of named files; no list of file names is allowed in this case. -
-F
fmt
Supplies astrftime
(see man page strftime(3)) string for the formatting of the time elements. The format string supports all of the zsh extensions described in Prompt Expansion. The-s
option is implied. -
-g
Show the time elements in the GMT time zone. The-s
option is implied. -
-l
List the names of the type elements (to standard output or an array as appropriate) and return immediately; arguments, and options other than-A
, are ignored. -
-L
Perform anlstat
(see man page lstat(2)) rather than astat
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 thelink
element useful. It’s important to note that this is the exact opposite from man page ls(1), etc. -
-n
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. -
-N
Never show the names of files. -
-o
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-r
and-s
options, nor whether a mode is shown at all. -
-r
Print raw data (the default format) alongside string data (the-s
format); the string data appears in parentheses after the raw data. -
-s
Printmode
,uid
,gid
and the three time elements as strings instead of numbers. In each case the format is like that ofls -l
. -
-t
Always show the type names for the elements ofstruct stat
. Usually these are only shown when output is to standard output and no individual element has been selected. -
-T
Never show the type names of thestruct stat
elements.
22.27 The zsh/system Module
The zsh/system
module makes available various builtin commands and
parameters.
22.27.1 Builtins
syserror
[ -e
errvar
] [ -p
prefix
] [ errno
|
errname
]
This command prints out the error message associated with errno
, a
system error number, followed by a newline to standard error.
Instead of the error number, a name errname
, for example ENOENT
, may
be used. The set of names is the same as the contents of the array
errnos
, see below.
If the string prefix
is given, it is printed in front of the error
message, with no intervening space.
If errvar
is supplied, the entire message, without a newline, is
assigned to the parameter names errvar
and nothing is output.
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).
sysopen
[ -arw
] [ -m
permissions
] [ -o
options
]
``-u
fd
file
This command opens a file. The -r
, -w
and -a
flags indicate
whether the file should be opened for reading, writing and appending,
respectively. The -m
option allows the initial permissions to use when
creating a file to be specified in octal form. The file descriptor is
specified with -u
. 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.
The -o
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.
-
cloexec
mark file to be closed when other programs are executed (else the file descriptor remains open in subshells and forked external -
create
creat
create file if it does not exist -
excl
create file, error if it already exists -
noatime
suppress updating of the file atime -
nofollow
fail iffile
is a symbolic link -
sync
request that writes wait until data has been physically written -
truncate
trunc
truncate file to size 0
To close the file, use one of the following:
exec {fd}<&-
exec {fd}>&-
sysread
[ -c
countvar
] [ -i
infd
] [ -o
outfd
]
[ -s
bufsize
] [ -t
timeout
] [ param
]
Perform a single system read from file descriptor infd
, or zero if
that is not given. The result of the read is stored in param
or
REPLY
if that is not given. If countvar
is given, the number of
bytes read is assigned to the parameter named by countvar
.
The maximum number of bytes read is bufsize
or 8192 if that is not
given, however the command returns as soon as any number of bytes was
successfully read.
If timeout
is given, it specifies a timeout in seconds, which may be
zero to poll the file descriptor. This is handled by the poll
system
call if available, otherwise the select
system call if available.
If outfd
is given, an attempt is made to write all the bytes just read
to the file descriptor outfd
. If this fails, because of a system error
other than EINTR
or because of an internal zsh error during an
interrupt, the bytes read but not written are stored in the parameter
named by param
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
countvar
if that is supplied. If it was successful, countvar
contains the full number of bytes transferred, as usual, and param
is
not set.
The error EINTR
(interrupted system call) is handled internally so
that shell interrupts are transparent to the caller. Any other error
causes a return.
The possible return statuses are
-
0
At least one byte of data was successfully read and, if appropriate, written. -
1
There was an error in the parameters to the command. This is the only error for which a message is printed to standard error. -
2
There was an error on the read, or on polling the input file descriptor for a timeout. The parameterERRNO
gives the error. -
3
Data were successfully read, but there was an error writing them tooutfd
. The parameterERRNO
gives the error. -
4
The attempt to read timed out. Note this does not setERRNO
as this is not a system error. -
5
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 tooutfd
is attempted.
sysseek
[ -u
fd
] [ -w
start
|end
|current
] offset
The current file position at which future reads and writes will take
place is adjusted to the specified byte offset. The offset
is
evaluated as a math expression. The -u
option allows the file
descriptor to be specified. By default the offset is specified relative
to the start or the file but, with the -w
option, it is possible to
specify that the offset should be relative to the current position or
the end of the file.
syswrite
[ -c
countvar
] [ -o
outfd
] data
The data (a single string of bytes) are written to the file descriptor
outfd
, or 1 if that is not given, using the write
system call.
Multiple write operations may be used if the first does not write all
the data.
If countvar
is given, the number of byte written is stored in the
parameter named by countvar
; this may not be the full length of data
if an error occurred.
The error EINTR
(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 EAGAIN
(on some systems, EWOULDBLOCK
) may result in the command returning
early.
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 ERRNO
will reflect the
error that occurred.
zsystem flock
[ -t
timeout
] [ -f
var
] [-er
] file
zsystem flock -u
fd_expr
The builtin zsystem
’s subcommand flock
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.
In the first form the named file
, 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 print
builtin with the -u
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.
‘ (print message) >> ``file
’. Status 0 is returned if the lock
succeeds, else status 1.
In the second form the file descriptor given by the arithmetic
expression fd_expr
is closed, releasing a lock. The file descriptor
can be queried by using the ‘-f
var
’ form during the lock; on a
successful lock, the shell variable var
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 ‘exec {``var``}>&-
’;
however, the form described here performs a safety check that the file
descriptor is in use for file locking.
By default the shell waits indefinitely for the lock to succeed. The
option -t
timeout
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.
If the option -e
is given, the file descriptor for the lock is
preserved when the shell uses exec
to start a new process; otherwise
it is closed at that point and the lock released.
If the option -r
is given, the lock is only for reading, otherwise it
is for reading and writing. The file descriptor is opened accordingly.
zsystem supports
subcommand
The builtin zsystem
’s subcommand supports
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: subcommand
is known but not supported by
the current operating system, or subcommand
is not known (possibly
because this is an older version of the shell before it was
implemented).
22.27.2 Math Functions
systell(fd)
The systell math function returns the current file position for the file descriptor passed as an argument.
22.27.3 Parameters
errnos
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
errno.h
. The index of each name (assuming the option KSH_ARRAYS
is
unset) corresponds to the error number. Error numbers num
before the
last known error which have no name are given the name E``num
in the
array.
Note that aliases for errors are not handled; only the canonical name is used.
sysparams
A readonly associative array. The keys are:
-
pid
Returns the process ID of the current process, even in subshells. Compare
$$
, which returns the process ID of the main shell process. -
ppid
Returns the process ID of the parent of the current process, even in subshells. Compare
$PPID
, which returns the process ID of the parent of the main shell process. -
procsubstpid
Returns the process ID of the last process started for process substitution, i.e. the<(``...``)
and>(``...``)
expansions.
22.28 The zsh/net/tcp Module
The zsh/net/tcp
module makes available one builtin command:
ztcp
[ -acflLtv
] [ -d
fd
] [ args
]
ztcp
is implemented as a builtin to allow full use of shell command
line editing, file I/O, and job control mechanisms.
If ztcp
is run with no options, it will output
If it is run with only the option -L
, 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:
-
File descriptor
The file descriptor in use for the connection. For normal inbound (I
) and outbound (O
) connections this may be read and written by the usual shell mechanisms. However, it should only be close with ‘ztcp -c
’. -
Connection type
A letter indicating how the session was created:-
Z
A session created with thezftp
command. -
L
A connection opened for listening with ‘ztcp -l
’. -
I
An inbound connection accepted with ‘ztcp -a
’. -
O
An outbound connection created with ‘ztcp
host
...
’.
-
-
The local host
This is usually set to an all-zero IP address as the address of the localhost is irrelevant. -
The local port
This is likely to be zero unless the connection is for listening. -
The remote host
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. -
The remote port
This is zero for a connection opened for listening.
22.28.1 Outbound Connections
-
ztcp
[-v
] [-d
fd
]host
[port
]
Open a new TCP connection tohost
. If theport
is omitted, it will default to port 23. The connection willREPLY
will be set to the file descriptor associated with that connection.If
-d
is specified, its argument will be taken as the target file descriptor for the connection.In order to elicit more verbose output, use
-v
.
22.28.2 Inbound Connections
-
ztcp
-l
[-v
] [-d
fd
]port
ztcp -l
will open a socket listening on TCPport
. The socket will be added to the will be set to the file descriptor associated with that listener.If
-d
is specified, its argument will be taken as the target file descriptor for the connection.In order to elicit more verbose output, use
-v
. -
ztcp
-a
[-tv
] [-d
targetfd
]listenfd
ztcp -a
will accept an incoming connection to the port associated withlistenfd
. The connection will be added to the session be set to the file descriptor associated with the inbound connection.If
-d
is specified, its argument will be taken as the target file descriptor for the connection.If
-t
is specified,ztcp
will return if no incoming connection is pending. Otherwise it will wait for one.In order to elicit more verbose output, use
-v
.
22.28.3 Closing Connections
-
ztcp
-cf
[-v
] [fd
]
ztcp
-c
[-v
] [fd
]
ztcp -c
will close the socket associated withfd
. The socket will be removed from theNormally, sockets registered by zftp (see The zsh/zftp Module ) cannot be closed this way. In order to force such a socket closed, use
-f
.In order to elicit more verbose output, use
-v
.
22.28.4 Example
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.
On host1
,
zmodload zsh/net/tcp
ztcp -l 5123
listenfd=$REPLY
ztcp -a $listenfd
fd=$REPLY
The second from last command blocks until there is an incoming connection.
Now create a connection from host2
(which may, of course, be the same
machine):
zmodload zsh/net/tcp
ztcp host1 5123
fd=$REPLY
Now on each host, $fd
contains a file descriptor for talking to the
other. For example, on host1
:
print This is a message >&$fd
and on host2
:
read -r line <&$fd; print -r - $line
prints ‘This is a message
’.
To tidy up, on host1
:
ztcp -c $listenfd
ztcp -c $fd
and on host2
ztcp -c $fd
22.29 The zsh/termcap Module
The zsh/termcap
module makes available one builtin command:
echotc
cap
[ arg
... ]
Output the termcap value corresponding to the capability cap
, with
optional arguments.
The zsh/termcap
module makes available one parameter:
termcap
An associative array that maps termcap capability codes to their values.
22.30 The zsh/terminfo Module
The zsh/terminfo
module makes available one builtin command:
echoti
cap
[ arg
]
Output the terminfo value corresponding to the capability cap
,
instantiated with arg
if applicable.
The zsh/terminfo
module makes available one parameter:
terminfo
An associative array that maps terminfo capability names to their values.
22.31 The zsh/zftp Module
The zsh/zftp
module makes available one builtin command:
zftp
subcommand
[ args
]
The zsh/zftp
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 zsh
distribution and is described in Zftp Function
System. However, the
zftp
command is entirely usable in its own right.
All commands consist of the command name zftp
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 ZFTP_VERBOSE
for more
information on how responses from the server may be printed.
22.31.1 Subcommands
open
host
[:``port
] [ user
[ password
[ account
] ] ]
Open a new FTP session to host
, 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 host``:``port
, open a connection to TCP port
port
instead of the standard FTP port 21. This may be the name of a
TCP service or a number: see the description of ZFTP_PORT
below for
more information.
If IPv6 addresses in colon format are used, the host
should be
surrounded by quoted square brackets to distinguish it from the port
,
for example ’[fe80::203:baff:fe02:8b56]’
. For consistency this is
allowed with all forms of host
.
Remaining arguments are passed to the login
subcommand. Note that if
no arguments beyond host
are supplied, open
will not automatically
call login
. If no arguments at all are supplied, open
will use the
parameters set by the params
subcommand.
After a successful open, the shell variables ZFTP_HOST
, ZFTP_PORT
,
ZFTP_IP
and ZFTP_SYSTEM
are available; see ‘Variables’ below.
login
[ name
[ password
[ account
] ] ]
user
[ name
[ password
[ account
] ] ]
Login the user name
with parameters password
and account
. Any of
the parameters can be omitted, and will be read from standard input if
needed (name
is always needed). If standard input is a terminal, a
prompt for each one will be printed on standard error and password
will not be echoed. If any of the parameters are not used, a warning
message is printed.
After a successful login, the shell variables ZFTP_USER
,
ZFTP_ACCOUNT
and ZFTP_PWD
are available; see ‘Variables’ below.
This command may be re-issued when a user is already logged in, and the server will first be reinitialized for a new user.
params
[ host
[ user
[ password
[ account
] ] ] ]
params
-
Store the given parameters for a later open
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.
Any of the parameters may be specified as a ‘?
’, 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 login
subcommand,
including special handling of password
. If the ‘?
’ 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 ‘\
’; hence an argument "\\$word"
guarantees that the string from the shell parameter $word
will be
treated literally, whether or not it begins with a ‘?
’.
If instead a single ‘-
’ is given, the existing parameters, if any, are
deleted. In that case, calling open
with no arguments will cause an
error.
The list of parameters is not deleted after a close
, however it will
be deleted if the zsh/zftp
module is unloaded.
For example,
zftp params ftp.elsewhere.xx juser '?Password for juser: '
will store the host ftp.elsewhere.xx
and the user juser
and then
prompt the user for the corresponding password with the given prompt.
test
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 test
subcommand is silent, apart from messages printed by the $ZFTP_VERBOSE
mechanism, or error messages if the connection closes. There is no
network overhead for this test.
The test is only supported on systems with either the select(2)
or
poll(2)
system calls; otherwise the message ‘not supported on this system
’ is printed instead.
The test
subcommand will automatically be called at the start of any
other subcommand for the current session when a connection is open.
cd
directory
Change the remote directory to directory
. Also alters the shell
variable ZFTP_PWD
.
cdup
Change the remote directory to the one higher in the directory tree.
Note that cd ..
will also work correctly on non-UNIX systems.
dir
[ arg
... ]
Give a (verbose) listing of the remote directory. The arg
s are passed
directly to the server. The command’s behaviour is implementation
dependent, but a UNIX server will typically interpret arg
s as
arguments to the ls
command and with no arguments return the result of
‘ls -l
’. The directory is listed to standard output.
ls
[ arg
... ]
Give a (short) listing of the remote directory. With no arg
, produces
a raw list of the files in the directory, one per line. Otherwise, up to
vagaries of the server implementation, behaves similar to dir
.
type
[ type
]
Change the type for the transfer to type
, or print the current type if
type
is absent. The allowed values are ‘A
’ (ASCII), ‘I
’ (Image,
i.e. binary), or ‘B
’ (a synonym for ‘I
’).
The FTP default for a transfer is ASCII. However, if zftp
finds that
the remote host is a UNIX machine with 8-bit byes, it will automatically
switch to using binary for file transfers upon open
. This can
subsequently be overridden.
The transfer type is only passed to the remote host when a data connection is established; this command involves no network overhead.
ascii
The same as type A
.
binary
The same as type I
.
mode
[ S
| B
]
Set the mode type to stream (S
) or block (B
). Stream mode is the
default; block mode is not widely supported.
remote
file
...
local
[ file
... ]
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 CCYYMMDDhhmmSS
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 [[
builtin’s <
and >
operators, even if
they are too long to be represented as integers.
Not all servers support the commands for retrieving this information. In
that case, the remote
command will print nothing and return status 2,
compared with status 1 for a file not found.
The local
command (but not remote
) 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 put
command with no further
redirection.
get
file
...
Retrieve all file
s from the server, concatenating them and sending
them to standard output.
put
file
...
For each file
, read a file from standard input and send that to the
remote host with the given name.
append
file
...
As put
, but if the remote file
already exists, data is appended to
it instead of overwriting it.
getat
file
point
putat
file
point
appendat
file
point
Versions of get
, put
and append
which will start the transfer at
the given point
in the remote file
. 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).
delete
file
...
Delete the list of files on the server.
mkdir
directory
Create a new directory directory
on the server.
rmdir
directory
Delete the directory directory
on the server.
rename
old-name
new-name
Rename file old-name
to new-name
on the server.
site
arg
...
Send a host-specific command to the server. You will probably only need this if instructed by the server to use it.
quote
arg
...
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 STAT
and HELP
. Note also the mechanism for
returning messages as described for the variable ZFTP_VERBOSE
below,
in particular that all messages from the control connection are sent to
standard error.
close
quit
Close the current data connection. This unsets the shell parameters
ZFTP_HOST
, ZFTP_PORT
, ZFTP_IP
, ZFTP_SYSTEM
, ZFTP_USER
,
ZFTP_ACCOUNT
, ZFTP_PWD
, ZFTP_TYPE
and ZFTP_MODE
.
session
[ sessname
]
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
‘default
’. 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 sessname
, or create a new session of
that name.
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 close
), and any user
parameters specified with the params
subcommand. Changing to a
previous session restores those values; changing to a new session
initialises them in the same way as if zftp
had just been loaded. The
name of the current session is given by the parameter ZFTP_SESSION
.
rmsession
[ sessname
]
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 ‘default
’ is created and becomes the current session;
note that this is a new session even if the session being deleted is
also called ‘default
’. It is recommended that sessions not be deleted
while background commands which use zftp
are still active.
22.31.2 Parameters
The following shell parameters are used by zftp
. Currently none of
them are special.
ZFTP_TMOUT
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.
ZFTP_IP
Readonly. The IP address of the current connection in dot notation.
ZFTP_HOST
Readonly. The hostname of the current remote server. If the host was
opened as an IP number, ZFTP_HOST
contains that instead; this saves
the overhead for a name lookup, as IP numbers are most commonly used
when a nameserver is unavailable.
ZFTP_PORT
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.
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 zftp open
will also need to be in this format.
ZFTP_SYSTEM
Readonly. The system type string returned by the server in response to
an FTP SYST
request. The most interesting case is a string beginning
"UNIX Type: L8"
, which ensures maximum compatibility with a local UNIX
host.
ZFTP_TYPE
Readonly. The type to be used for data transfers , either ‘A
’ or
‘I
’. Use the type
subcommand to change this.
ZFTP_USER
Readonly. The username currently logged in, if any.
ZFTP_ACCOUNT
Readonly. The account name of the current user, if any. Most servers do not require an account name.
ZFTP_PWD
Readonly. The current directory on the server.
ZFTP_CODE
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.
ZFTP_REPLY
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.
ZFTP_SESSION
Readonly. The name of the current FTP session; see the description of
the session
subcommand.
ZFTP_PREFS
A string of preferences for altering aspects of zftp
’s behaviour. Each
preference is a single character. The following are defined:
-
P
Passive: attempt to make the remote server initiate data transfers. This is slightly more efficient than sendport mode. If the letterS
occurs later in the string,zftp
will use sendport mode if passive mode is not available. -
S
Sendport: initiate transfers by the FTPPORT
command. If this occurs before anyP
in the string, passive mode will never be attempted. -
D
Dumb: use only the bare minimum of FTP commands. This prevents the variablesZFTP_SYSTEM
andZFTP_PWD
from being set, and will mean all connections default to ASCII type. It may preventZFTP_SIZE
from being set during a transfer if the server does not send it anyway (many servers do).
If ZFTP_PREFS
is not set when zftp
is loaded, it will be set to a
default of ‘PS
’, i.e. use passive mode if available, otherwise fall
back to sendport mode.
ZFTP_VERBOSE
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:
-
1.
A positive preliminary reply. -
2.
A positive completion reply. -
3.
A positive intermediate reply. -
4.
A transient negative completion reply. -
5.
A permanent negative completion reply.
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’.
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.
If ZFTP_VERBOSE
is not set when zftp
is loaded, it will be set to
the default value 450
, 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.
22.31.3 Functions
zftp_chpwd
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, $ZFTP_PWD
will be
unset; otherwise it will reflect the new directory.
zftp_progress
If this function is set by the user, it will be called during a get
,
put
or append
operation each time sufficient data has been received
from the host. During a get
, the data is sent to standard output, so
it is vital that this function should write to standard error or
directly to the terminal, not to standard output.
When it is called with a transfer in progress, the following additional shell parameters are set:
ZFTP_FILE
The name of the remote file being transferred from or to.
ZFTP_TRANSFER
A G
for a get
operation and a P
for a put
operation.
ZFTP_SIZE
The total size of the complete file being transferred: the same as the
first value provided by the remote
and local
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.
ZFTP_COUNT
The amount of data so far transferred; a number between zero and
$ZFTP_SIZE
, if that is set. This number is always available.
The function is initially called with ZFTP_TRANSFER
set appropriately
and ZFTP_COUNT
set to zero. After the transfer is finished, the
function will be called one more time with ZFTP_TRANSFER
set to GF
or PF
, in case it wishes to tidy up. It is otherwise never called
twice with the same value of ZFTP_COUNT
.
Sometimes the progress meter may cause disruption. It is up to the user
to decide whether the function should be defined and to use unfunction
when necessary.
22.31.4 Problems
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 zftp
. Other status changes in subshells will
not be reflected by changes to the variables (but should be otherwise
harmless).
Deleting sessions while a zftp
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.
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.
22.32 The zsh/zle Module
The zsh/zle
module contains the Zsh Line Editor. See Zsh Line
Editor.
22.33 The zsh/zleparameter Module
The zsh/zleparameter
module defines two special parameters that can be
used to access internal information of the Zsh Line Editor (see Zsh
Line Editor).
keymaps
This array contains the names of the keymaps currently defined.
widgets
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 ‘builtin
’ for builtin widgets, a string of the
form ‘user:``name
’ for user-defined widgets, where name
is the name
of the shell function implementing the widget, a string of the form
‘completion:``type``:``name
’ for completion widgets, or a null value
if the widget is not yet fully defined. In the penultimate case, type
is the name of the builtin widget the completion widget imitates in its
behavior and name
is the name of the shell function implementing the
completion widget.
22.34 The zsh/zprof Module
When loaded, the zsh/zprof
causes shell functions to be profiled. The
profiling results can be obtained with the zprof
builtin command made
available by this module. There is no way to turn profiling off other
than unloading the module.
zprof
[ -c
]
Without the -c
option, zprof
lists profiling results to standard
output. The format is comparable to that of commands like gprof
.
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
‘[``num``]
’, 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.
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.
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.
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.
As long as the zsh/zprof
module is loaded, profiling will be done and
multiple invocations of the zprof
builtin command will show the times
and numbers of calls since the module was loaded. With the -c
option,
the zprof
builtin command will reset its internal counters and will
not show the listing.
22.35 The zsh/zpty Module
The zsh/zpty
module offers one builtin:
zpty
[ -e
] [ -b
] name
[ arg
... ]
The arguments following name
are concatenated with spaces between,
then executed as a command, as if passed to the eval
builtin. The
command runs under a newly assigned pseudo-terminal; this is useful for
running commands non-interactively which expect an interactive
environment. The name
is not part of the command, but is used to refer
to this command in later calls to zpty
.
With the -e
option, the pseudo-terminal is set up so that input
characters are echoed.
With the -b
option, input to and output from the pseudo-terminal are
made non-blocking.
The shell parameter REPLY
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 Zle
Builtins) or manipulated with
sysread
and syswrite
(see The zsh/system
Module). Warning: Use of sysread
and
syswrite
is not recommended; use zpty -r
and zpty -w
unless you
know exactly what you are doing.
zpty
-d
[ name
... ]
The second form, with the -d
option, is used to delete commands
previously started, by supplying a list of their name
s. If no name
is given, all commands are deleted. Deleting a command causes the HUP
signal to be sent to the corresponding process.
zpty
-w
[ -n
] name
[ string
... ]
The -w
option can be used to send the to command name
the given
string
s as input (separated by spaces). If the -n
option is not
given, a newline is added at the end.
If no string
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
-n
option is not applied.
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.
zpty
-r
[ -mt
] name
[ param
[ pattern
] ]
The -r
option can be used to read the output of the command name
.
With only a name
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.
When also given a param
argument, at most one line is read and stored
in the parameter named param
. 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 param
.
If a pattern
is given as well, output is read until the whole string
read matches the pattern
, 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
-m
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.
In all cases, the return status is non-zero if nothing could be read,
and is 2
if this is because the command has finished.
If the -r
option is combined with the -t
option, zpty
tests
whether output is available before trying to read. If no output is
available, zpty
immediately returns the status 1
. When used with a
pattern
, 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.
zpty
-t
name
The -t
option without the -r
option can be used to test whether the
command name
is still running. It returns a zero status if the command
is running and a non-zero value otherwise.
zpty
[ -L
]
The last form, without any arguments, is used to list the commands
currently defined. If the -L
option is given, this is done in the form
of calls to the zpty
builtin.
22.36 The zsh/zselect Module
The zsh/zselect
module makes available one builtin command:
zselect
[ -rwe
] [ -t
timeout
] [ -a
array
] [ -A
assoc
] [ fd
... ]
The zselect
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.
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. zselect
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 -r
, -w
and -e
, 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.
(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
exception condition, of which the only standard example is out-of-band
data received on a socket. So zsh users are unlikely to find the -e
option useful.)
The option ‘-t
timeout
’ specifies a timeout in hundredths of a
second. This may be zero, in which case the file descriptors will simply
be polled and zselect
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.
The option ‘-a
array
’ indicates that array
should be set to
indicate the file descriptor(s) which are ready. If the option is not
given, the array reply
will be used for this purpose. The array will
contain a string similar to the arguments for zselect
. For example,
zselect -t 0 -r 0 -w 1
might return immediately with status 0 and $reply
containing ‘-r 0 -w 1
’ to show that both file descriptors are ready for the requested
operations.
The option ‘-A
assoc
’ indicates that the associative array assoc
should be set to indicate the file descriptor(s) which are ready. This
option overrides the option -a
, nor will reply
be modified. The keys
of assoc
are the file descriptors, and the corresponding values are
any of the characters ‘rwe
’ to indicate the condition.
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.
22.37 The zsh/zutil Module
The zsh/zutil
module only adds some builtins:
zstyle
[ -L
[ metapattern
[ style
] ] ]
zstyle
[ -e
| -
| -``-
] pattern
style
string
...
zstyle -d
[ pattern
[ style
... ] ]
zstyle -g
name
[ pattern
[ style
] ]
zstyle -
{a
|b
|s
} context
style
name
[ sep
]
zstyle -
{T
|t
} context
style
[ string
... ]
zstyle -m
context
style
pattern
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 ‘context’, which is matched against the patterns. The definition stored for the most specific pattern that matches will be returned.
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 ‘*
’. A ‘*
’ 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.
Example
For example, to define your preferred form of precipitation depending on
which city you’re in, you might set the following in your zshrc
:
zstyle ':weather:europe:*' preferred-precipitation rain
zstyle ':weather:europe:germany:* preferred-precipitation none
zstyle ':weather:europe:germany:*:munich' preferred-precipitation snow
Then, the fictional ‘weather
’ plugin might run under the hood a
command such as
zstyle -s ":weather:${continent}:${country}:${county}:${city}" preferred-precipitation REPLY
in order to retrieve your preference into the scalar variable $REPLY
.
Usage
The forms that operate on patterns are the following.
-
zstyle
[-L
[metapattern
[style
] ] ]
Without arguments, lists style definitions. Styles are shown in alphabetic order and patterns are shown in the orderzstyle
will test them.If the
-L
option is given, listing is done in the form of calls tozstyle
. The optional first argument,metapattern
, is a pattern which will be matched against the string supplied aspattern
when the style was defined. Note: this means, for example, ‘zstyle -L ":completion:*"
’ will match any supplied pattern beginning ‘:completion:
’, not just":completion:*"
: use’:completion:\*’
to match that. The optional second argument limits the output to a specificstyle
(not a pattern).-L
is not compatible with any other options. -
zstyle
[-
|-``-
|-e
]pattern
style
string
...
Defines the given
style
for thepattern
with thestring
s as the value. If the-e
option is given, thestring
s will be concatenated (separated by spaces) and the resulting string will be evaluated (in the same way as it is done by theeval
builtin command) when the style is looked up. In this case the parameter ‘reply
’ must be assigned to set the strings returned after the evaluation. Before evaluating the value,reply
is unset, and if it is still unset after the evaluation, the style is treated as if it were not set. -
zstyle -d
[pattern
[style
... ] ]
Delete style definitions. Without arguments all definitions are deleted, with apattern
all definitions for that pattern are deleted and if anystyle
s are given, then only those styles are deleted for thepattern
. -
zstyle -g
name
[pattern
[style
] ]
Retrieve a style definition. Thename
is used as the name of an array in which the results are stored. Without any further arguments, all patterns defined are returned. With apattern
the styles defined for that pattern are returned and with both apattern
and astyle
, the value strings of that combination is returned.
The other forms can be used to look up or test styles for a given context.
-
zstyle -s
context
style
name
[sep
]
The parametername
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 thesep
string if that is given) between them.Return
0
if the style is set,1
otherwise. -
zstyle -b
context
style
name
The value is stored inname
as a boolean, i.e. as the string ‘yes
’ if the value has only one string and that string is equal to one of ‘yes
’, ‘true
’, ‘on
’, or ‘1
’. If the value is any other string or has more than one string, the parameter is set to ‘no
’.Return
0
ifname
is set to ‘yes
’,1
otherwise. -
zstyle -a
context
style
name
The value is stored inname
as an array. Ifname
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.Return
0
if the style is set,1
otherwise. -
zstyle -t
context
style
[string
... ]
zstyle -T
context
style
[string
... ]
Test the value of a style, i.e. the-t
option only returns a status (sets$?
). Without anystring
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 ‘true
’, ‘yes
’, ‘on
’ or ‘1
’. If anystring
s are given the status is zero if and only if at least one of thestring
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 is1
. If the style is not defined, the status is2
.The
-T
option tests the values of the style like-t
, but it returns status zero (rather than2
) if the style is not defined for any matching pattern. -
zstyle -m
context
style
pattern
Match a value. Returns status zero if thepattern
matches at least one of the strings in the value.
zformat -f
param
format
spec
...
zformat -a
array
sep
spec
...
This builtin provides two different forms of formatting. The first form
is selected with the -f
option. In this case the format
string will
be modified by replacing sequences starting with a percent sign in it
with strings from the spec
s. Each spec
should be of the form
‘char``:``string
’ which will cause every appearance of the sequence
‘%``char
’ in format
to be replaced by the string
. The ‘%
’
sequence may also contain optional minimum and maximum field width
specifications between the ‘%
’ and the ‘char
’ in the form
‘%``min``.``max``c
’, 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 string
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 string
will be
truncated after that many characters. After all ‘%
’ sequences for the
given spec
s have been processed, the resulting string is stored in the
parameter param
.
The %
-escapes also understand ternary expressions in the form used by
prompts. The %
is followed by a ‘(
’ and then an ordinary format
specifier character as described above. There may be a set of digits
either before or after the ‘(
’; 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 ‘%(``X``.``text1``.``text2``)
’, except that
the ‘.
’ character is arbitrary. The value given for the format
specifier in the char``:``string
expressions is evaluated as a
mathematical expression, and compared with the test number. If they are
the same, text1
is output, else text2
is output. A parenthesis may
be escaped in text2
as %)
. Either of text1
or text2
may contain
nested %
-escapes.
For example:
zformat -f REPLY "The answer is '%3(c.yes.no)'." c:3
outputs "The answer is ’yes’." to REPLY
since the value for the format
specifier c
is 3, agreeing with the digit argument to the ternary
expression.
The second form, using the -a
option, can be used for aligning
strings. Here, the spec
s are of the form ‘left``:``right
’ where
‘left
’ and ‘right
’ are arbitrary strings. These strings are
modified by replacing the colons by the sep
string and padding the
left
strings with spaces to the right so that the sep
strings in the
result (and hence the right
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 right
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 left
string can be escaped with a backslash. The resulting strings
are stored in the array
.
zregexparse
This implements some internals of the _regex_arguments
function.
zparseopts
[ -D
-E
-F
-K
-M
] [ -a
array
] [ -A
assoc
] [ -
] spec
...
This builtin simplifies the parsing of options in positional parameters,
i.e. the set of arguments given by $*
. Each spec
describes one
option and must be of the form ‘opt
[=``array
]’. If an option
described by opt
is found in the positional parameters it is copied
into the array
specified with the -a
option; if the optional
‘=``array
’ is given, it is instead copied into that array, which
should be declared as a normal array and never as an associative array.
Note that it is an error to give any spec
without an ‘=``array
’
unless one of the -a
or -A
options is used.
Unless the -E
option is given, parsing stops at the first string that
isn’t described by one of the spec
s. Even with -E
, parsing always
stops at a positional parameter equal to ‘-
’ or ‘-``-
’. See also
-F
.
The opt
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.
-
name
name``+
Thename
is the name of the option without the leading ‘-
’. To specify a GNU-style long option, one of the usual two leading ‘-
’ must be included inname
; for example, a ‘-``-file
’ option is represented by aname
of ‘-file
’.If a ‘
+
’ appears aftername
, the option is appended toarray
each time it is found in the positional parameters; without the ‘+
’ only the last occurrence of the option is preserved.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 ‘
-
’ (unless the-E
option is used). -
name``:
name``:-
name``::
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 thearray
after the option itself.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 ‘
:-
’ form is used, in which case the argument is put into the same element.A ‘
+
’ as described above may appear between thename
and the first colon.
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 ‘-
’. There is no special handling of ‘=
’ as with GNU-style
argument parsers; given the spec
‘-foo:
’, the positional parameter
‘-``-foo=bar
’ is parsed as ‘-``-foo
’ with an argument of ‘=bar
’.
When the names of two options that take no arguments overlap, the
longest one wins, so that parsing for the spec
s ‘-foo -foobar
’ (for
example) is unambiguous. However, due to the aforementioned handling of
option-arguments, ambiguities may arise when at least one overlapping
spec
takes an argument, as in ‘-foo: -foobar
’. In that case, the
last matching spec
wins.
The options of zparseopts
itself cannot be stacked because, for
example, the stack ‘-DEK
’ is indistinguishable from a spec
for the
GNU-style long option ‘-``-DEK
’. The options of zparseopts
itself
are:
-
-a
array
As described above, this names the default array in which to store the recognised options. -
-A
assoc
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. -
-D
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 thespec
s. If the first such parameter is ‘-
’ or ‘-``-
’, it is removed as well. This is similar to using theshift
builtin. -
-E
This changes the parsing rules to not stop at the first string that isn’t described by one of thespec
s. It can be used to test for or (if used together with-D
) 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 ‘-
’ or ‘-``-
’ not described by aspec
, but it is not removed when used with-D
. -
-F
If this option is given,zparseopts
immediately stops at the first option-like parameter not described by one of thespec
s, prints an error message, and returns status 1. Removal (-D
) and extraction (-E
) are not performed, and option arrays are not updated. This provides basic validation for the given options.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.
-
-K
With this option, the arrays specified with the-a
option and with the ‘=``array
’ forms are kept unchanged when none of thespec
s for them is used. Otherwise the entire array is replaced when any of thespec
s is used. Individual elements of associative arrays specified with the-A
option are preserved by-K
. This allows assignment of default values to arrays before callingzparseopts
. -
-M
This changes the assignment rules to implement a map among equivalent option names. If anyspec
uses the ‘=``array
’ form, the stringarray
is interpreted as the name of anotherspec
, which is used to choose where to store the values. If no otherspec
is found, the values are stored as usual. This changes only the way the values are stored, not the way$*
is parsed, so results may be
For example,
set -- -a -bx -c y -cz baz -cend
zparseopts a=foo b:=bar c+:=bar
will have the effect of
foo=(-a)
bar=(-b x -c y -c z)
The arguments from ‘baz
’ on will not be used.
As an example for the -E
option, consider:
set -- -a x -b y -c z arg1 arg2
zparseopts -E -D b:=bar
will have the effect of
bar=(-b y)
set -- -a x -c z arg1 arg2
I.e., the option -b
and its arguments are taken from the positional
parameters and put into the array bar
.
The -M
option can be used like this:
set -- -a -bx -c y -cz baz -cend
zparseopts -A bar -M a=foo b+: c:=b
to have the effect of
foo=(-a)
bar=(-a '' -b xyz)
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
23 Calendar Function System
23.1 Description
The shell is supplied with a series of functions to replace and enhance
the traditional Unix calendar
programme, which warns the user of
imminent or future events, details of which are stored in a text file
(typically calendar
in the user’s home directory). The version
provided here includes a mechanism for alerting the user when an event
is due.
In addition functions age
, before
and after
are provided that can
be used in a glob qualifier; they allow files to be selected based on
their modification times.
The format of the calendar
file and the dates used there in and in the
age
function are described first, then the functions that can be
called to examine and modify the calendar
file.
The functions here depend on the availability of the zsh/datetime
module which is usually installed with the shell. The library function
strptime()
must be available; it is present on most recent operating
systems.
23.2 File and Date Formats
23.2.1 Calendar File Format
The calendar file is by default ~/calendar
. This can be configured by
the calendar-file
style, see Styles. 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.
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
(&
) is ignored for compatibility.
An indented line on which the first non-whitespace character is #
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
calendar_add
.
The Emacs extension that a date with no description may refer to a number of succeeding events at different times is not supported.
Unless the done-file
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 .done
, hence ~/calendar.done
by
default.
An example is shown below.
23.2.2 Date Format
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 "month" does not match "Monday". Furthermore, time zones are not handled; all times are assumed to be local.
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.
- In particular, note the confusion between
month``/``day``/``year
andday``/``month``/``year
when the month is numeric; these formats should be avoided if at all possible. Many alternatives are available. - The year must be given in full to avoid confusion, and only years from 1900 to 2099 inclusive are matched.
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).
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
More detailed rules follow.
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:
HH``:``MM
[:``SS
[.``FFFFF
]] [am
|pm
|a.m.
|p.m.
]HH``:``MM``.``SS
[.``FFFFF
] [am
|pm
|a.m.
|p.m.
]
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 calendar
file and the
age
, before
and after
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 a.m.
or p.m.
or one of their variants is present, an
hour without a minute is allowed, e.g. 3 p.m.
.
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:
+0100
GMT
GMT-7
CET+1CDT
Any part of the timezone that is not numeric must have exactly three capital letters in the name.
Dates suffer from the ambiguity between DD``/``MM``/``YYYY
and
MM``/``DD``/``YYYY
. It is recommended this form is avoided with purely
numeric dates, but use of ordinals, eg. 3rd/04/2007
, 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 19
or 20
); 03/04/08
is not recognised. Other numbers may have leading zeroes, but they are
not required. The following are handled:
YYYY``/``MM``/``DD
YYYY``-``MM``-``DD
YYYY``/``MNM``/``DD
YYYY``-``MNM``-``DD
DD
[th
|st
|rd
]MNM
[,
] [YYYY
]MNM
DD
[th
|st
|rd
][,
] [YYYY
]DD
[th
|st
|rd
]/``MM
[,
]YYYY
DD
[th
|st
|rd
]/``MM``/``YYYY
MM``/``DD
[th
|st
|rd
][,
]YYYY
MM``/``DD
[th
|st
|rd
]/``YYYY
Here, MNM
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.
Where the year is shown as optional, the current year is assumed. There
are only two such cases, the form Jun 20
or 14 September
(the only
two commonly occurring forms, apart from a "the" 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.
Times may follow dates with a colon, e.g. 1965/07/12:09:45
; this is in
order to provide a format with no whitespace. A comma and whitespace are
allowed, e.g. 1965/07/12, 09:45
. Currently the order of these
separators is not checked, so illogical formats such as 1965/07/12, : ,09:45
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.
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 yesterday
,
today
and tomorrow
are handled. All matches are case-insensitive.
Hence if today is Monday, then Sunday
is equivalent to yesterday
,
Monday
is equivalent to today
, but Tuesday
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
Tomorrow, 8 p.m.
.
For example, the standard date format:
Fri Aug 18 17:00:48 BST 2006
is handled by matching HH``:``MM``:``SS
and removing it together with
the matched (but unused) time zone. This leaves the following:
Fri Aug 18 2006
Fri
is ignored and the rest is matched according to the standard
rules.
23.2.3 Relative Time Format
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.
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.
Anchors are available in the following cases. If one or two times are
passed to the function calendar
, 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 WARN
keyword; likewise, the scheduled event anchors a
repetition period when given by the RPT
keyword, so that
specifications such as RPT 2 months, 3rd Thursday
are handled
properly. Finally, the -R
argument to calendar_scandate
directly
provides an anchor for relative calculations.
The periods handled, with possible abbreviations are:
-
Years
years
,yrs
,ys
,year
,yr
,y
,yearly
. A year is 365.25 days unless there is an anchor. -
Months
months
,mons
,mnths
,mths
,month
,mon
,mnth
,mth
,monthly
. Note thatm
,ms
,mn
,mns
are ambiguous and are not handled. A month is a period of 30 days rather than a calendar month unless there is an anchor. -
Weeks
weeks
,wks
,ws
,week
,wk
,w
,weekly
-
Days
days
,dys
,ds
,day
,dy
,d
,daily
-
Hours
hours
,hrs
,hs
,hour
,hr
,h
,hourly
-
Minutes
minutes
,mins
,minute
,min
, but notm
,ms
,mn
ormns
-
Seconds
seconds
,secs
,ss
,second
,sec
,s
Spaces between the numbers are optional, but are required between items, although a comma may be used (with or without spaces).
The forms yearly
to hourly
allow the number to be omitted; it is
assumed to be 1. For example, 1 d
and daily
are equivalent. Note
that using those forms with plurals is confusing; 2 yearly
is the same
as 2 years
, not twice yearly, so it is recommended they only be used
without numbers.
When an anchor time is present, there is an extension to handle regular
events in the form of the n
th some
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
n
(th
|st
|rd
) day
, for example 1st Tuesday
or 3rd Monday
. 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).
Here are some examples:
30 years 3 months 4 days 3:42:41
14 days 5 hours
Monthly, 3rd Thursday
4d,10hr
23.2.4 Example
Here is an example calendar file. It uses a consistent date format, as recommended above.
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
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 calendar_add
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.
23.3 User Functions
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.
23.3.1 Calendar system functions
calendar
[ -abdDsv
] [ -C
calfile
] [ -n
num
] [
-S
showprog
]
[ [ start
] end
]
calendar -r
[ -abdDrsv
] [ -C
calfile
] [ -n
num
] [
-S
showprog
]
[ start
]
Show events in the calendar.
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.
If end
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.
end
may start with a +
, 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.
If start
is also given, show events starting from that time and date.
The word now
can be used to indicate the current time.
To implement an alert when events are due, include calendar -s
in your
~/.zshrc
file.
Options:
-
-a
Show all items in the calendar, regardless of thestart
andend
. -
-b
Brief: don’t display continuation lines (i.e. indented lines following the line with the date/time), just the first line. -
-B
lines
Brief: display at most the firstlines
lines of the calendar entry. ‘-B 1
’ is equivalent to ‘-b
’. -
-C
calfile
Explicitly specify a calendar file instead of the value of thecalendar-file
style or the default~/calendar
. -
-d
Move any events that have passed from the calendar file to the "done" file, as given by thedone-file
style or the default which is the calendar file with.done
appended. This option is implied by the-s
option. -
-D
Turns off the option-d
, even if the-s
option is also present. -
-n
num
,-``num
Show at leastnum
events, if present in the calendar file, regardless of thestart
andend
. -
-r
Show all the remaining options in the calendar, ignoring the givenend
time. Thestart
time is respected; any argument given is treated as astart
time. -
-s
Use the shell’ssched
command to schedule a timed event that will warn the user when an event is due. Note that thesched
command only runs if the shell is at an interactive prompt; a foreground task blocks the scheduled task from running until it is finished.The timed event usually runs the programme
calendar_show
to show the event, as described in Utility functions.By default, a warning of the event is shown five minutes before it is due. The warning period can be configured by the style
warn-time
or for a single calendar entry by includingWARN
reltime
in the first line of the entry, wherereltime
is one of the usual relative time formats.A repeated event may be indicated by including
RPT
reldate
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 timereldate
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.If
RPT
is used, it is also possible to specify that certain recurrences of an event are rescheduled or cancelled. This is done with theOCCURRENCE
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 stringCANCELLED
. In this case the date and time must be in exactly the "date with local time" format used by thetext/calendar
MIME type (RFC 2445),<YYYY><MM><DD>``T``<hh><mm><ss>
(note the presence of the literal characterT
). 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 isXXXXXXXXTXXXXXX
.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
RECURRENCE
and a time or date in the same format.calendar_add
adds such an indication when it encounters a recurring event that does not include one, based on the headline date/time.If
calendar_add
is used to update occurrences theUID
keyword described there should be present in both the existing entry and the added occurrence in order to identify recurring event sequences.For example,
Thu May 6, 2010 11:00 Informal chat RPT 1 week # RECURRENCE 20100506T110000 # OCCURRENCE 20100513T110000 20100513T120000 # OCCURRENCE 20100520T110000 CANCELLED
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
#
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 ‘Thu May 13, 2010 12:00
’ while theRECURRENCE
date/time will be ‘20100513T110000
’ (note that cancelled and moved events are not taken account of in theRECURRENCE
, which records what the next regular recurrence is, but they are accounted for in the headline date/time).It is safe to run
calendar -s
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.By default, expired events are moved to the "done" file; see the
-d
option. Use-D
to prevent this. -
-S
showprog
Explicitly specify a programme to be used for showing events instead of the value of theshow-prog
style or the defaultcalendar_show
. -
-v
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.
calendar_add
[ -BL
] event
...
Adds a single event to the calendar in the appropriate location. The
event can contain multiple lines, as described in File and Date
Formats. 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 .old
.
The option -B
indicates that backing up the calendar file will be
handled by the caller and should not be performed by calendar_add
. The
option -L
indicates that calendar_add
does not need to lock the
calendar file as it is already locked. These options will not usually be
needed by users.
If the style reformat-date
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 date-format
.
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 UID
, 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 #
, for example:
Aug 31, 2007 09:30 Celebrate the end of the holidays
# UID 045B78A0
The second line will not be shown by the calendar
function.
It is possible to specify the RPT
keyword followed by CANCELLED
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 UID
is required
in order to match an existing event in the calendar.
calendar_add
will attempt to manage recurrences and occurrences of
repeating events as described for event scheduling by calendar -s
above. To reschedule or cancel a single event calendar_add
should be
called with an entry that includes the correct UID
but does not
include the RPT
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
OCCURRENCE
keyword in the entry passed to calendar_add
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.
calendar_edit
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 VISUAL
, if set, else the variable EDITOR
.
If the calendar scheduler was running, then after editing the file
calendar -s
is called to update it.
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.
calendar_parse
calendar-entry
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
reply
to an empty associative array. Otherwise, it returns status 0
and sets elements of the associative array reply
as follows:
-
time
The time as a string of digits in the same units as$EPOCHSECONDS
-
schedtime
The regularly scheduled time. This may differ from the actual event timetime
if this is a recurring event and the next occurrence has been rescheduled. Thentime
gives the actual time andschedtime
the time of the regular recurrence before modification. -
text1
The text from the line not including the date and time of the event, but including anyWARN
orRPT
keywords and values. -
warntime
Any warning time given by theWARN
keyword as a string of digits containing the time at which to warn in the same units as$EPOCHSECONDS
. (Note this is an absolute time, not the relative time passed down.) Not set noWARN
keyword and value were matched. -
warnstr
The raw string matched after theWARN
keyword, else unset. -
rpttime
Any recurrence time given by theRPT
keyword as a string of digits containing the time of the recurrence in the same units as$EPOCHSECONDS
. (Note this is an absolute time.) Not set if noRPT
keyword and value were matched. -
schedrpttime
The next regularly scheduled occurrence of a recurring event before modification. This may differ fromrpttime
, which is the actual time of the event that may have been rescheduled from the regular time. -
rptstr
The raw string matched after theRPT
keyword, else unset. -
text2
The text from the line after removal of the date and any keywords and values.
calendar_showdate
[ -r
] [ -f
fmt
] date-spec
...
The given date-spec
is interpreted and the corresponding date and time
printed. If the initial date-spec
begins with a +
or -
it is
treated as relative to the current time; date-spec
s after the first
are treated as relative to the date calculated so far and a leading +
is optional in that case. This allows one to use the system as a date
calculator. For example, calendar_showdate ’+1 month, 1st Friday’
shows the date of the first Friday of next month.
With the option -r
nothing is printed but the value of the date and
time in seconds since the epoch is stored in the parameter REPLY
.
With the option -f
fmt
the given date/time conversion format is
passed to strftime
; see notes on the date-format
style below.
In order to avoid ambiguity with negative relative date specifications,
options must occur in separate words; in other words, -r
and -f
should not be combined in the same word.
calendar_sort
Sorts the calendar file into date and time order. The old calendar is
left in a file with the suffix .old
.
23.3.2 Glob qualifiers
-
age
The function
age
can be autoloaded and use separately from the calendar system, although it uses the functioncalendar_scandate
for date formatting. It requires thezsh/stat
builtin, but uses only the builtinzstat
.age
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 File and Date Formats.The function can take one or two arguments, which can be supplied either directly as command or arguments, or separately as shell parameters.
print *(e:age 2006/10/04 2006/10/09:)
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
+
:print *(e:age 2006/10/04 +5d:)
The example above is equivalent to the previous example.
In addition to the special use of days of the week,
today
andyesterday
, times with no date may be specified; these apply to today. Obviously such uses become problematic around midnight.print *(e-age 12:00 13:30-)
The example above shows files modified between 12:00 and 13:00 today.
print *(e:age 2006/10/04:)
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).
print *(e-age 2006/10/04:10:15 2006/10/04:10:45-)
The example above supplies times. Note that whitespace within the time and date specification must be quoted to ensure
age
receives the correct arguments, hence the use of the additional colon to separate the date and time.AGEREF=2006/10/04:10:15 AGEREF2=2006/10/04:10:45 print *(+age)
This shows the same example before using another form of argument passing. The dates and times in the parameters
AGEREF
andAGEREF2
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.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:
print *(e-age :file1-)
matches all files created on the same day (24 hours starting from midnight) as
file1
.print *(e-age :file1 :file2-)
matches all files modified no earlier than
file1
and no later thanfile2
; precision here is to the nearest second. -
after
before
The functions
after
andbefore
are simpler versions ofage
that take just one argument. The argument is parsed similarly to an argument ofage
; if it is not given the variableAGEREF
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.The two following examples are therefore equivalent:
print *(e-after 12:00-) print *(e-after today:12:00-)
23.4 Styles
The zsh style mechanism using the zstyle
command is describe in The
zsh/zutil Module. This is
the same mechanism used in the completion system.
The styles below are all examined in the context
:datetime:``function``:
, for example :datetime:calendar:
.
calendar-file
The location of the main calendar. The default is ~/calendar
.
date-format
A strftime
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 %D{``string``}
prompt format in Prompt
Expansion.
This is used for outputting dates in calendar
, both to support the
-v
option and when adding recurring events back to the calendar file,
and in calendar_showdate
as the final output format.
If the style is not set, the default used is similar the standard system
format as output by the date
command (also known as ‘ctime format’):
‘%a %b %d %H:%M:%S %Z %Y
’.
done-file
The location of the file to which events which have passed are appended.
The default is the calendar file location with the suffix .done
. The
style may be set to an empty string in which case a "done" file will not
be maintained.
reformat-date
Boolean, used by calendar_add
. 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 date-format
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.
show-prog
The programme run by calendar
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 calendar -s
uses a
start time and stop time equal to one another to indicate alerts for
specific events.
The default is the function calendar_show
.
warn-time
The time before an event at which a warning will be displayed, if the
first line of the event does not include the text EVENT
reltime
. The
default is 5 minutes.
23.5 Utility functions
calendar_lockfiles
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
file``.lockfile
. 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 calendar_edit
is
used.
Three attempts are made to lock the file before giving up. If the module
zsh/zselect
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.
The files locked are appended to the array lockfiles
, which should be
local to the caller.
If all files were successfully locked, status zero is returned, else status one.
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.
calendar_read
This is a backend used by various other functions to parse the calendar
file, which is passed as the only argument. The array calendar_entries
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.
calendar_scandate
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 File and Date
Formats. The parameter REPLY
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.
Returns status zero if the date and time were successfully parsed, else one.
Options:
-
-a
The date and time are anchored to the start of the argument; they will not be matched if there is preceding text. -
-A
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. -
-d
Enable additional debugging output. -
-m
Minus. When-R
anchor_time
is also given the relative time is calculated backwards fromanchor_time
. -
-r
The argument passed is to be parsed as a relative time. -
-R
anchor_time
The argument passed is to be parsed as a relative time. The time is relative toanchor_time
, a time in seconds since the epoch, and the returned value is the absolute time corresponding to advancinganchor_time
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. -
-s
In addition to settingREPLY
, setREPLY2
to the remainder of the argument after the date and time have been stripped. This is empty if the option-A
was given. -
-t
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.
calendar_show
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.
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.
If the parameter DISPLAY
is set and the start and end times are the
same (indicating a scheduled event), the function uses the command
xmessage
to display a window with the event details.
23.6 Bugs
As the system is based entirely on shell functions (with a little
support from the zsh/datetime
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.
There is no calendar_delete
function.
There is no localization support for dates and times, nor any support for the use of time zones.
Relative periods of months and years do not take into account the variable number of days.
The calendar_show
function is currently hardwired to use xmessage
for displaying alerts on X Window System displays. This should be
configurable and ideally integrate better with the desktop.
calendar_lockfiles
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.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 24 TCP Function System
24 TCP Function System
24.1 Description
A module zsh/net/tcp
is provided to provide network I/O over TCP/IP
from within the shell; see its description in Zsh
Modules. 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 zsh/net/tcp
module, the zsh/zselect
module is
used to implement timeouts on read operations. For troubleshooting tips,
consult the corresponding advice for the zftp
functions described in
Zftp Function System.
There are functions corresponding to the basic I/O operations open,
close, read and send, named tcp_open
etc., as well as a function
tcp_expect
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.
To use the system where it is available, it should be enough to
‘autoload -U tcp_open
’ and run tcp_open
as documented below to
start a session. The tcp_open
function will autoload the remaining
functions.
24.2 TCP User Functions
24.2.1 Basic I/O
tcp_open
[ -qz
] host port
[ sess
]
tcp_open
[ -qz
] [ -s
sess
| -l
sess
[,
...] ] ...
tcp_open
[ -qz
] [ -a
fd
| -f
fd
] [ sess
]
Open a new session. In the first and simplest form, open a TCP
connection to host host
at port port
; numeric and symbolic forms are
understood for both.
If sess
is given, this becomes the name of the session which can be
used to refer to multiple different TCP connections. If sess
is not
given, the function will invent a numeric name value (note this is not
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.
In the second case, one or more sessions to be opened are given by name.
A single session name is given after -s
and a comma-separated list
after -l
; both options may be repeated as many times as necessary. A
failure to open any session causes tcp_open
to abort. The host and
port are read from the file .ztcp_sessions
in the same directory as
the user’s zsh initialisation files, i.e. usually the home directory,
but $ZDOTDIR
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.
The third form allows passive and fake TCP connections. If the option
-a
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 ‘ztcp -l
port
’ will create one with the
file descriptor stored in the parameter $REPLY
. The listening port can
be closed with ‘ztcp -c
fd
’. A call to ‘tcp_open -a
fd
’ will
block until a remote TCP connection is made to port
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.
If the option -f
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.
If the option -q
is given with any of the three forms, tcp_open
will
not print informational messages, although it will in any case exit with
an appropriate status.
If the line editor (zle) is in use, which is typically the case if the
shell is interactive, tcp_open
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 -z
to any of the forms of tcp_open
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 vared
builtin. The option has no effect if zle is not
active; ‘[[ -o zle]]
’ will test for this.
The first session to be opened becomes the current session and
subsequent calls to tcp_open
do not change it. The current session is
stored in the parameter $TCP_SESS
; see below for more detail about the
parameters used by the system.
The function tcp_on_open
, if defined, is called when a session is
opened. See the description below.
tcp_close
[ -qn
] [ -a
| -l
sess
[,
...] | sess
... ]
Close the named sessions, or the current session if none is given, or
all open sessions if -a
is given. The options -l
and -s
are both
handled for consistency with tcp_open
, although the latter is
redundant.
If the session being closed is the current one, $TCP_SESS
is unset,
leaving no current session, even if there are other sessions still open.
If the session was opened with tcp_open -f
, 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 -n
is given, no attempt will be made to
close file descriptors in this case. The -n
option is not used for
genuine ztcp
session; the file descriptors are always closed with the
session.
If the option -q
is given, no informational messages will be printed.
tcp_read
[ -bdq
] [ -t
TO
] [ -T
TO
]
[ -a
| -u
fd
[,
...] | -l
sess
[,
...] | -s
sess
... ]
Perform a read operation on the current session, or on a list of
sessions if any are given with -u
, -l
or -s
, or all open sessions
if the option -a
is given. Any of the -u
, -l
or -s
options may
be repeated or mixed together. The -u
option specifies a file
descriptor directly (only those managed by this system are useful), the
other two specify sessions as described for tcp_open
above.
The function checks for new data available on all the sessions listed.
Unless the -b
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 $TCP_LINE
, and displayed to standard output
unless $TCP_SILENT
contains a non-empty string. When printed to
standard output the string $TCP_PROMPT
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, tcp_read
can be called repeatedly until it returns status 2
which indicates all pending input from all specified sessions has been
handled.
With the option -b
, 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.
The option -d
indicates that all pending input should be drained. In
this case tcp_read
may process multiple lines in the manner given
above; only the last is stored in $TCP_LINE
, but the complete set is
stored in the array $tcp_lines
. This is cleared at the start of each
call to tcp_read
.
The options -t
and -T
specify a timeout in seconds, which may be a
floating point number for increased accuracy. With -t
the timeout is
applied before each line read. With -T
, the timeout applies to the
overall operation, possibly including multiple read operations if the
option -d
is present; without this option, there is no distinction
between -t
and -T
.
The function does not print informational messages, but if the option
-q
is given, no error message is printed for a non-existent session.
A return status of 2 indicates a timeout or no data to read. Any other non-zero return status indicates some error condition.
See tcp_log
for how to control where data is sent by tcp_read
.
tcp_send
[ -cnq
] [ -s
sess
| -l
sess
[,
...] ] data
...
tcp_send
[ -cnq
] -a
data
...
Send the supplied data strings to all the specified sessions in turn.
The underlying operation differs little from a ‘print -r
’ to the
session’s file descriptor, although it attempts to prevent the shell
from dying owing to a SIGPIPE
caused by an attempt to write to a
defunct session.
The option -c
causes tcp_send
to behave like cat
. 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 data
arguments
to individual tcp_send
commands.
The option -n
prevents tcp_send
from putting a newline at the end of
the data strings.
The remaining options all behave as for tcp_read
.
The data arguments are not further processed once they have been passed
to tcp_send
; they are simply passed down to print -r
.
If the parameter $TCP_OUTPUT
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 $TCP_OUTPUT
in front where appropriate, much in the
manner of $TCP_PROMPT
.
24.2.2 Session Management
tcp_alias
[ -q
] alias``=``sess
...
tcp_alias
[ -q
] [ alias
... ]
tcp_alias
-d
[ -q
] alias
...
This function is not particularly well tested.
The first form creates an alias for a session name; alias
can then be
used to refer to the existing session sess
. As many aliases may be
listed as required.
The second form lists any aliases specified, or all aliases if none.
The third form deletes all the aliases listed. The underlying sessions are not affected.
The option -q
suppresses an inconsistently chosen subset of error
messages.
tcp_log
[ -asc
] [ -n
| -N
] [ logfile
]
With an argument logfile
, all future input from tcp_read
will be
logged to the named file. Unless -a
(append) is given, this file will
first be truncated or created empty. With no arguments, show the current
status of logging.
With the option -s
, per-session logging is enabled. Input from
tcp_read
is output to the file logfile``.``sess
. As the session is
automatically discriminated by the filename, the contents are raw (no
$TCP_PROMPT
). The option -a
applies as above. Per-session logging
and logging of all data in one file are not mutually exclusive.
The option -c
closes all logging, both complete and per-session logs.
The options -n
and -N
respectively turn off or restore output of
data read by tcp_read
to standard output; hence ‘tcp_log -cn
’ turns
off all output by tcp_read
.
The function is purely a convenient front end to setting the parameters
$TCP_LOG
, $TCP_LOG_SESS
, $TCP_SILENT
, which are described below.
tcp_rename
old
new
Rename session old
to session new
. The old name becomes invalid.
tcp_sess
[ sess
[ command
[ arg
... ] ] ]
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 $tcp_by_name
, $tcp_by_fd
and $TCP_SESS
is probably more convenient; see below.
With a sess
argument, set the current session to sess
. This is
equivalent to changing $TCP_SESS
directly.
With additional arguments, temporarily set the current session while
executing ‘command
arg
...’. command
is re-evaluated so as to
expand aliases etc., but the remaining arg
s are passed through as that
appear to tcp_sess
. The original session is restored when tcp_sess
exits.
24.2.3 Advanced I/O
tcp_command
send-option
... send-argument
...
This is a convenient front-end to tcp_send
. All arguments are passed
to tcp_send
, then the function pauses waiting for data. While data is
arriving at least every $TCP_TIMEOUT
(default 0.3) seconds, data is
handled and printed out according to the current settings. Status 0 is
always returned.
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.
tcp_expect
[ -q
] [ -p
var
| -P
var
] [ -t
TO
|
-T
TO
]
[ -a
| -s
sess
| -l
sess
[,
...] ] pattern
...
Wait for input matching any of the given pattern
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 $TCP_LINE
, and the full set of lines read during the
call to tcp_expect
is stored in the array $tcp_expect_lines
.
Sessions are specified in the same way as tcp_read
: the default is to
use the current session, otherwise the sessions specified by -a
, -s
,
or -l
are used.
Each pattern
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 ‘*
’ at the start and end. The line matched against includes
the $TCP_PROMPT
added by tcp_read
. It is possible to include the
globbing flags ‘#b
’ or ‘#m
’ in the patterns to make backreferences
available in the parameters $MATCH
, $match
, etc., as described in
the base zsh documentation on pattern matching.
Unlike tcp_read
, the default behaviour of tcp_expect
is to block
indefinitely until the required input is found. This can be modified by
specifying a timeout with -t
or -T
; these function as in tcp_read
,
specifying a per-read or overall timeout, respectively, in seconds, as
an integer or floating-point number. As tcp_read
, the function returns
status 2 if a timeout occurs.
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 -p
var
can be used; on return, $var
is set to the number of the pattern
using ordinary zsh indexing, i.e. the first is 1, and so on. Note the
absence of a ‘$
’ in front of var
. To avoid clashes, the parameter
cannot begin with ‘_expect
’. The index -1 is used if there is a
timeout and 0 if there is no match.
The option -P
var
works similarly to -p
, 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 var
is set when the
argument matches. The tag timeout
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.
The option -q
is passed directly down to tcp_read
.
As all input is done via tcp_read
, all the usual rules about output of
lines read apply. One exception is that the parameter $tcp_lines
will
only reflect the line actually matched by tcp_expect
; use
$tcp_expect_lines
for the full set of lines read during the function
call.
tcp_proxy
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.
The first argument is a TCP port on which the function will listen.
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.
The command is run in the background, so tcp_proxy
can then accept new
connections. It continues to accept new connections until interrupted.
tcp_spam
[ -ertv
] [ -a
| -s
sess
| -l
sess
[,
...]
] cmd
[ arg
... ]
Execute ‘cmd
[ arg
... ]’ for each session in turn. Note this
executes the command and arguments; it does not send the command line as
data unless the -t
(transmit) option is given.
The sessions may be selected explicitly with the standard -a
, -s
or
-l
options, or may be chosen implicitly. If none of the three options
is given the rules are: first, if the array $tcp_spam_list
is set,
this is taken as the list of sessions, otherwise all sessions are taken.
Second, any sessions given in the array $tcp_no_spam_list
are removed
from the list of sessions.
Normally, any sessions added by the ‘-a
’ flag or when all sessions are
chosen implicitly are spammed in alphabetic order; sessions given by the
$tcp_spam_list
array or on the command line are spammed in the order
given. The -r
flag reverses the order however it was arrived it.
The -v
flag specifies that a $TCP_PROMPT
will be output before each
session. This is output after any modification to TCP_SESS
by the
user-defined tcp_on_spam
function described below. (Obviously that
function is able to generate its own output.)
If the option -e
is present, the line given as ‘cmd
[ arg
... ]’
is executed using eval
, otherwise it is executed without any further
processing.
tcp_talk
This is a fairly simple-minded attempt to force input to the line editor
to go straight to the default TCP_SESS
.
An escape string, $TCP_TALK_ESCAPE
, default ‘:
’, 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.
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
‘%
’) to ‘tcp_command -``-
’.
tcp_wait
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 tcp_read -a
. This is similar
to the interactive behaviour at the command prompt when zle handlers are
installed.
24.2.4 ‘One-shot’ file transfer
-
tcp_point
port
tcp_shoot
host
port
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 usingcat
.tcp_point
reads any data arriving atport
and sends it to standard output;tcp_shoot
connects toport
onhost
and sends its standard input. Any unusedport
may be used; the standard mechanism for picking a port is to think of a random four-digit number above 1024 until one works.To transfer a file from host
woodcock
to hostspringes
, onspringes
:tcp_point 8091 >output_file
and on
woodcock
:tcp_shoot springes 8091 <input_file
As these two functions do not require
tcp_open
to set up a TCP connection first, they may need to be autoloaded separately.
24.3 TCP User-defined Functions
Certain functions, if defined by the user, will be called by the
function system in certain contexts. This facility depends on the module
zsh/parameter
, 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.
Typically, these are called after the requested action has been taken, so that the various parameters will reflect the new state.
tcp_on_alias
alias
fd
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.
tcp_on_awol
sess
fd
If the function tcp_fd_handler
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 tcp_on_awol
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
tcp_fd_handler
should return immediately with the given status.
Typically the action of tcp_on_awol
will be to close the session.
The variable TCP_INVALIDATE_ZLE
will be a non-empty string if it is
necessary to invalidate the line editor display using ‘zle -I
’ before
printing output from the function.
(‘AWOL’ is military jargon for ‘absent without leave’ or some variation. It has no pre-existing technical meaning known to the author.)
tcp_on_close
sess
fd
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.
tcp_on_open
sess
fd
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, tcp_open
will continue to attempt to open any remaining
sessions given on the command line.
tcp_on_rename
oldsess
fd
newsess
This is called after a session has been renamed with the three arguments old session name, file descriptor, new session name.
tcp_on_spam
sess
command ...
This is called once for each session spammed, just before a command is
executed for a session by tcp_spam
. The arguments are the session name
followed by the command list to be executed. If tcp_spam
was called
with the option -t
, the first command will be tcp_send
.
This function is called after $TCP_SESS
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 $TCP_SESS
within this function. For example, the
session arguments to tcp_spam
could include extra information to be
stripped off and processed in tcp_on_spam
.
If the function sets the parameter $REPLY
to ‘done
’, the command
line is not executed; in addition, no prompt is printed for the -v
option to tcp_spam
.
tcp_on_unalias
alias
fd
This is called with the name of an alias and the corresponding session’s file descriptor after an alias has been deleted.
24.4 TCP Utility Functions
The following functions are used by the TCP function system but will rarely if ever need to be called directly.
tcp_fd_handler
This is the function installed by tcp_open
for handling input from
within the line editor, if that is required. It is in the format
documented for the builtin ‘zle -F
’ in Zle
Builtins .
While active, the function sets the parameter TCP_HANDLER_ACTIVE
to 1.
This allows shell code called internally (for example, by setting
tcp_on_read
) to tell if is being called when the shell is otherwise
idle at the editor prompt.
tcp_output
[ -q
] -P
prompt
-F
fd
-S
sess
This function is used for both logging and handling output to standard
output, from within tcp_read
and (if $TCP_OUTPUT
is set) tcp_send
.
The prompt
to use is specified by -P
; the default is the empty
string. It can contain:
-
%c
Expands to 1 if the session is the current session, otherwise 0. Used with ternary expressions such as ‘%(c.-.+)
’ to output ‘+
’ for the current session and ‘-
’ otherwise. -
%f
Replaced by the session’s file descriptor. -
%s
Replaced by the session name. -
%%
Replaced by a single ‘%
’.
The option -q
suppresses output to standard output, but not to any log
files which are configured.
The -S
and -F
options are used to pass in the session name and file
descriptor for possible replacement in the prompt.
24.5 TCP User Parameters
Parameters follow the usual convention that uppercase is used for scalars and integers, while lowercase is used for normal and associative array. It is always safe for user code to read these parameters. Some parameters may also be set; these are noted explicitly. Others are included in this group as they are set by the function system for the user’s benefit, i.e. setting them is typically not useful but is benign.
For example, ‘local TCP_SILENT=1
’ specifies that data read during the
function call will not be printed to standard output, regardless of the
setting outside the function. Likewise, ‘local TCP_SESS=``sess
’ sets a
session for the duration of a function, and ‘local TCP_PROMPT=
’
specifies that no prompt is used for input during the function.
tcp_expect_lines
Array. The set of lines read during the last call to tcp_expect
,
including the last ($TCP_LINE
).
tcp_filter
Array. May be set directly. A set of extended globbing patterns which,
if matched in tcp_output
, will cause the line not to be printed to
standard output. The patterns should be defined as described for the
arguments to tcp_expect
. Output of line to log files is not affected.
TCP_HANDLER_ACTIVE
Scalar. Set to 1 within tcp_fd_handler
to indicate to functions called
recursively that they have been called during an editor session.
Otherwise unset.
TCP_LINE
The last line read by tcp_read
, and hence also tcp_expect
.
TCP_LINE_FD
The file descriptor from which $TCP_LINE
was read.
${tcp_by_fd[$TCP_LINE_FD]}
will give the corresponding session name.
tcp_lines
Array. The set of lines read during the last call to tcp_read
,
including the last ($TCP_LINE
).
TCP_LOG
May be set directly, although it is also controlled by tcp_log
. The
name of a file to which output from all sessions will be sent. The
output is proceeded by the usual $TCP_PROMPT
. If it is not an absolute
path name, it will follow the user’s current directory.
TCP_LOG_SESS
May be set directly, although it is also controlled by tcp_log
. The
prefix for a set of files to which output from each session separately
will be sent; the full filename is ${TCP_LOG_SESS}.``sess
. 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.
tcp_no_spam_list
Array. May be set directly. See tcp_spam
for how this is used.
TCP_OUTPUT
May be set directly. If a non-empty string, any data sent to a session
by tcp_send
will be logged. This parameter gives the prompt to be used
in a file specified by $TCP_LOG
but not in a file generated from
$TCP_LOG_SESS
. The prompt string has the same format as TCP_PROMPT
and the same rules for its use apply.
TCP_PROMPT
May be set directly. Used as the prefix for data read by tcp_read
which is printed to standard output or to the log file given by
$TCP_LOG
, if any. Any ‘%s
’, ‘%f
’ or ‘%%
’ occurring in the string
will be replaced by the name of the session, the session’s underlying
file descriptor, or a single ‘%
’, respectively. The expression ‘%c
’
expands to 1 if the session being read is the current session, else 0;
this is most useful in ternary expressions such as ‘%(c.-.+)
’ which
outputs ‘+
’ if the session is the current one, else ‘-
’.
If the prompt starts with %P
, this is stripped and the complete result
of the previous stage is passed through standard prompt %
-style
formatting before being output.
TCP_READ_DEBUG
May be set directly. If this has non-zero length, tcp_read
will give
some limited diagnostics about data being read.
TCP_SECONDS_START
This value is created and initialised to zero by tcp_open.
The functions tcp_read
and tcp_expect
use the shell’s SECONDS
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 SECONDS
which is floating point and set the parameter
TCP_SECONDS_START
to the previous value of $SECONDS
. If the
parameter is already floating point, it is used without a local copy
being created and TCP_SECONDS_START
is not set. As the global value is
zero, the shell elapsed time is guaranteed to be the sum of $SECONDS
and $TCP_SECONDS_START
.
This can be avoided by setting SECONDS
globally to a floating point
value using ‘typeset -F SECONDS
’; then the TCP functions will never
make a local copy and never set TCP_SECONDS_START
to a non-zero value.
TCP_SESS
May be set directly. The current session; must refer to one of the
sessions established by tcp_open
.
TCP_SILENT
May be set directly, although it is also controlled by tcp_log
. If of
non-zero length, data read by tcp_read
will not be written to standard
output, though may still be written to a log file.
tcp_spam_list
Array. May be set directly. See the description of the function
tcp_spam
for how this is used.
TCP_TALK_ESCAPE
May be set directly. See the description of the function tcp_talk
for
how this is used.
TCP_TIMEOUT
May be set directly. Currently this is only used by the function
tcp_command
, see above.
24.6 TCP User-defined Parameters
The following parameters are not set by the function system, but have a special effect if set by the user.
tcp_on_read
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 EXTENDED_GLOB
).
Every line read from a TCP session directly or indirectly using
tcp_read
(which includes lines read by tcp_expect
) 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.
If any function called to handle a line returns a non-zero status, the
line is not output. Thus a tcp_on_read
handler containing only the
instruction ‘return 1
’ can be used to suppress output of particular
lines (see, however, tcp_filter
above). However, the line is still
stored in TCP_LINE
and tcp_lines
; this occurs after all
tcp_on_read
processing.
24.7 TCP Utility Parameters
These parameters are controlled by the function system; they may be read directly, but should not usually be set by user code.
tcp_aliases
Associative array. The keys are the names of sessions established with
tcp_open
; each value is a space-separated list of aliases which refer
to that session.
tcp_by_fd
Associative array. The keys are session file descriptors; each value is the name of that session.
tcp_by_name
Associative array. The keys are the names of sessions; each value is the file descriptor associated with that session.
24.8 TCP Examples
Here is a trivial example using a remote calculator.
To create a calculator server on port 7337 (see the dc
manual page for
quite how infuriating the underlying command is):
tcp_proxy 7337 dc
To connect to this from the same host with a session also named ‘dc
’:
tcp_open localhost 7337 dc
To send a command to the remote session and wait a short while for
output (assuming dc
is the current session):
tcp_command 2 4 + p
To close the session:
tcp_close
The tcp_proxy
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.
The following chunk of code puts a list of sessions into an xterm header, with the current session followed by a star.
print -n "\033]2;TCP:" ${(k)tcp_by_name:/$TCP_SESS/$TCP_SESS\*} "\a"
24.9 TCP Bugs
The function tcp_read
uses the shell’s normal read
builtin. As this
reads a complete line at once, data arriving without a terminating
newline can cause the function to block indefinitely.
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.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 25 Zftp Function System
25 Zftp Function System
25.1 Description
This describes the set of shell functions supplied with the source
distribution as an interface to the zftp
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 ftp
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.
The prerequisite is that the zftp
command, as described in The
zsh/zftp Module , must be
available in the version of zsh
installed at your site. If the shell
is configured to load new commands at run time, it probably is: typing
‘zmodload zsh/zftp
’ will make sure (if that runs silently, it has
worked). If this is not the case, it is possible zftp
was linked into
the shell anyway: to test this, type ‘which zftp
’ and if zftp
is
available you will get the message ‘zftp: shell built-in command
’.
Commands given directly with zftp
builtin may be interspersed between
the functions in this suite; in a few cases, using zftp
directly may
cause some of the status information stored in shell parameters to
become invalid. Note in particular the description of the variables
$ZFTP_TMOUT
, $ZFTP_PREFS
and $ZFTP_VERBOSE
for zftp
.
25.2 Installation
You should make sure all the functions from the Functions/Zftp
directory of the source distribution are available; they all begin with
the two letters ‘zf
’. 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 $fpath
array
(this should already be the case if they were installed), and at least
the function zfinit
should be autoloaded; it will autoload the rest.
Finally, to initialize the use of the system you need to call the
zfinit
function. The following code in your .zshrc
will arrange for
this; assume the functions are stored in the directory ~/myfns
:
fpath=(~/myfns $fpath)
autoload -U zfinit
zfinit
Note that zfinit
assumes you are using the zmodload
method to load
the zftp
command. If it is already built into the shell, change
zfinit
to zfinit -n
. It is helpful (though not essential) if the
call to zfinit
appears after any code to initialize the new completion
system, else unnecessary compctl
commands will be given.
25.3 Functions
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 getopts
builtin, for those functions that handle options
you must use ‘-``-
’ rather than ‘-
’ to ensure the remaining
arguments are treated literally (a single ‘-
’ is treated as an
argument).
25.3.1 Opening a connection
zfparams
[ host
[ user
[ password
... ] ] ]
Set or show the parameters for a future zfopen
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 host
is given,
and either the user
or password
is not, they will be prompted for;
also, any parameter given as ‘?
’ will be prompted for, and if the
‘?
’ is followed by a string, that will be used as the prompt. As
zfopen
calls zfparams
to store the parameters, this usually need not
be called directly.
A single argument ‘-
’ 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.
zfopen
[ -1
] [ host
[ user
[ password
[ account
] ]
] ]
If host
is present, open a connection to that host under username
user
with password password
(and, on the rare occasions when it is
necessary, account account
). If a necessary parameter is missing or
given as ‘?
’ it will be prompted for. If host
is not present, use a
previously stored set of parameters.
If the command was successful, and the terminal is compatible with
xterm
or is sun-cmd
, a summary will appear in the title bar, giving
the local host:directory
and the remote host:directory
; this is
handled by the function zftp_chpwd
, described below.
Normally, the host
, user
and password
are internally recorded for
later re-opening, either by a zfopen
with no arguments, or
automatically (see below). With the option ‘-1
’, 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 zfopen
on its own, or a zfopen -1
, never alters the stored
parameters.
Both zfopen
and zfanon
(but not zfparams
) understand URLs of the
form ftp://``host
/path...
as meaning to connect to the host
, then
change directory to path
(which must be a directory, not a file). The
‘ftp://
’ can be omitted; the trailing ‘/
’ is enough to trigger
recognition of the path
. Note prefixes other than ‘ftp:
’ are not
recognized, and that all characters after the first slash beyond host
are significant in path
.
zfanon
[ -1
] host
Open a connection host
for anonymous FTP. The username used is
‘anonymous
’. The password (which will be reported the first time) is
generated as user``@``host
; this is then stored in the shell parameter
$EMAIL_ADDR
which can alternatively be set manually to a
25.3.2 Directory management
zfcd
[ dir
]
zfcd -
zfcd
old
new
Change the current directory on the remote server: this is implemented
to have many of the features of the shell builtin cd
.
In the first form with dir
present, change to the directory dir
. The
command ‘zfcd ..
’ is treated specially, so is guaranteed to work on
non-UNIX servers (note this is handled internally by zftp
). If dir
is omitted, has the effect of ‘zfcd ~
’.
The second form changes to the directory previously current.
The third form attempts to change the current directory by replacing the
first occurrence of the string old
with the string new
in the
current directory.
Note that in this command, and indeed anywhere a remote filename is
expected, the string which on the local host corresponds to ‘~
’ is
converted back to a ‘~
’ before being passed to the remote machine.
This is convenient because of the way expansion is performed on the
command line before zfcd
receives a string. For example, suppose the
command is ‘zfcd ~/foo
’. The shell will expand this to a full path
such as ‘zfcd /home/user2/pws/foo
’. At this stage, zfcd
recognises
the initial path as corresponding to ‘~
’ and will send the directory
to the remote host as ~/foo
, so that the ‘~
’ will be expanded by the
server to the correct remote host directory. Other named directories of
the form ‘~name
’ are not treated in this fashion.
zfhere
Change directory on the remote server to the one corresponding to the
current local directory, with special handling of ‘~
’ as in zfcd
.
For example, if the current local directory is ~/foo/bar
, then
zfhere
performs the effect of ‘zfcd ~/foo/bar
’.
zfdir
[ -rfd
] [ -
] [ dir-options
] [ dir
]
Produce a long directory listing. The arguments dir-options
and dir
are passed directly to the server and their effect is implementation
dependent, but specifying a particular remote directory dir
is usually
possible. The output is passed through a pager given by the environment
variable $PAGER
, or ‘more
’ if that is not set.
The directory is usually cached for re-use. In fact, two caches are
maintained. One is for use when there is no dir-options
or dir
, 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
zfdir
with the same arguments; for example, repeated use of ‘zfdir /pub/gnu
’ will only require the directory to be retrieved on the first
call. Alternatively, this cache can be re-viewed with the -r
option.
As relative directories will confuse zfdir
, the -f
option can be
used to force the cache to be flushed before the directory is listed.
The option -d
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.
zfls
[ ls-options
] [ dir
]
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.
25.3.3 Status commands
zftype
[ type
]
With no arguments, show the type of data to be transferred, usually
ASCII or binary. With an argument, change the type: the types ‘A
’ or
‘ASCII
’ for ASCII data and ‘B
’ or ‘BINARY
’, ‘I
’ or ‘IMAGE
’
for binary data are understood case-insensitively.
zfstat
[ -v
]
Show the status of the current or last connection, as well as the status
of some of zftp
’s status variables. With the -v
option, a more
verbose listing is produced by querying the server for its version of
events, too.
25.3.4 Retrieving files
The commands for retrieving files all take at least two options. -G
suppresses remote filename expansion which would otherwise be performed
(see below for a more detailed description of that). -t
attempts to
set the modification time of the local file to that of the remote file:
see the description of the function zfrtime
below for more
information.
zfget
[ -Gtc
] file1
...
Retrieve all the listed files file1
... one at a time from the remote
server. If a file contains a ‘/
’, 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 ‘/
’. The option -c
(cat) forces all files
to be sent as a single stream to standard output; in this case the -t
option has no effect.
zfuget
[ -Gvst
] file1
...
As zfget
, 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 -s
, the command runs
silently and will always retrieve the file in either of those two cases.
With the option -v
, the command prints more information about the
files while it is working out whether or not to transfer them.
zfcget
[ -Gt
] file1
...
As zfget
, 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.
Note that this requires a commonly implemented, but non-standard, version of the FTP protocol, so is not guaranteed to work on all servers.
zfgcp
[ -Gt
] remote-file
local-file
zfgcp
[ -Gt
] rfile1
... ldir
This retrieves files from the remote server with arguments behaving
similarly to the cp
command.
In the first form, copy remote-file
from the server to the local file
local-file
.
In the second form, copy all the remote files rfile1
... into the
local directory ldir
retaining the same basenames. This assumes UNIX
directory semantics.
25.3.5 Sending files
zfput
[ -r
] file1
...
Send all the file1
... given separately to the remote server. If a
filename contains a ‘/
’, the full filename is used locally to find the
file, but only the basename is used for the remote file name.
With the option -r
, if any of the files
are directories they are
sent recursively with all their subdirectories, including files
beginning with ‘.
’. This requires that the remote machine understand
UNIX file semantics, since ‘/
’ is used as a directory separator.
zfuput
[ -vs
] file1
...
As zfput
, 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 zfuget
, but reversed between local and remote files.
zfcput
file1
...
As zfput
, 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 zfcget
.
zfpcp
local-file
remote-file
zfpcp
lfile1
... rdir
This sends files to the remote server with arguments behaving similarly
to the cp
command.
With two arguments, copy local-file
to the server as remote-file
.
With more than two arguments, copy all the local files lfile1
... into
the existing remote directory rdir
retaining the same basenames. This
assumes UNIX directory semantics.
A problem arises if you attempt to use zfpcp
lfile1
rdir
, i.e. the
second form of copying but with two arguments, as the command has no
simple way of knowing if rdir
corresponds to a directory or a
filename. It attempts to resolve this in various ways. First, if the
rdir
argument is ‘.
’ or ‘..
’ 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 ‘Is a directory
’,
then zfpcp
will retry using the second form.
25.3.6 Closing the connection
zfclose
Close the connection.
25.3.7 Session management
zfsession
[ -lvod
] [ sessname
]
Allows you to manage multiple FTP sessions at once. By default,
connections take place in a session called ‘default
’; by giving the
command ‘zfsession
sessname
’ 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 zfparams
. Hence you can have different
sessions set up to connect to different hosts, each remembering the
appropriate host, user and password.
With no arguments, zfsession
prints the name of the current session;
with the option -l
it lists all sessions which currently exist, and
with the option -v
it gives a verbose list showing the host and
directory for each session, where the current session is marked with an
asterisk. With -o
, it will switch to the most recent previous session.
With -d
, 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 ‘default
’ is created and made current.
It is safest not to delete sessions while background commands using
zftp
are active.
zftransfer
sess1``:``file1
sess2``:``file2
Transfer files between two sessions; no local copy is made. The file is
read from the session sess1
as file1
and written to session sess2
as file file2
; file1
and file2
may be relative to the current
directories of the session. Either sess1
or sess2
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;
file2
may be omitted or may end with a slash, in which case the
basename of file1
will be added. The sessions sess1
and sess2
must
be distinct.
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.
25.3.8 Bookmarks
The two functions zfmark
and zfgoto
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 $ZFTP_BMFILE
; if not set when one
of the two functions is called, it will be set to the file .zfbkmarks
in the directory where your zsh startup files live (usually ~
).
zfmark
[ bookmark
]
If given an argument, mark the current host, user and directory under
the name bookmark
for later use by zfgoto
. 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.
If not given an argument, list the existing bookmarks and the points to
which they refer in the form user``@``host``:``directory
; this is the
format in which they are stored, and the file may be edited directly.
zfgoto
[ -n
] bookmark
Return to the location given by bookmark
, as previously set by
zfmark
. If the location has user ‘ftp
’ or ‘anonymous
’, open the
connection with zfanon
, 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.
With the option -n
, the bookmark is taken to be a nickname stored by
the ncftp
program in its bookmark file, which is assumed to be
~/.ncftp/bookmarks
. The function works identically in other ways. Note
that there is no mechanism for adding or modifying ncftp
bookmarks
from the zftp functions.
25.3.9 Other functions
Mostly, these functions will not be called directly (apart from
zfinit
), but are described here for completeness. You may wish to
alter zftp_chpwd
and zftp_progress
, in particular.
zfinit
[ -n
]
As described above, this is used to initialize the zftp function system.
The -n
option should be used if the zftp command is already built into
the shell.
zfautocheck
[ -dn
]
This function is called to implement automatic reopening behaviour, as
described in more detail below. The options must appear in the first
argument; -n
prevents the command from changing to the old directory,
while -d
prevents it from setting the variable do_close
, 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 $zflastsession
, but the internal host/user/password
parameters must also be correctly set.
zfcd_match prefix suffix
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 zfget_match
and
hence completes all files, not just directories. On some systems,
directories may not even look like filenames.
zfget_match prefix suffix
This performs matching for completion of remote filenames. It caches
files for the current directory (only) in the shell parameter
$zftp_fcache
. It is in the form to be called by the -K
option of
compctl
, but also works when called from a widget-style completion
function with prefix
and suffix
set appropriately.
zfrglob varname
Perform remote globbing, as describes in more detail below. varname
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.
zfrtime
lfile
rfile
[ time
]
Set the local file lfile
to have the same modification time as the
remote file rfile
, or the explicit time time
in FTP format
CCYYMMDDhhmmSS
for the GMT timezone. This uses the shell’s
zsh/datetime
module to perform the conversion from GMT to local time.
zftp_chpwd
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
xterm
-compatible or sun-cmd
terminal emulator to reflect the local
and remote hostnames and current directories. It works best when
combined with the function chpwd
. In particular, a function of the
form
chpwd() {
if [[ -n $ZFTP_USER ]]; then
zftp_chpwd
else
# usual chpwd e.g put host:directory in title bar
fi
}
fits in well.
zftp_progress
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 ‘zstyle ’:zftp:*’ progress none
’. Note also that if you
alter it, any output must 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.
zffcache
This is used to implement caching of files in the current directory for
each session separately. It is used by zfget_match
and zfrglob
.
25.4 Miscellaneous Features
25.4.1 Configuration
Various styles are available using the standard shell style mechanism,
described in The zsh/zutil
Module. Briefly, the command
‘zstyle ’:zftp:*’
style
value
...’. defines the style
to have
value value
; 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
‘:zftp:zfget
’: the style will then have the given value only in
the zfget
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 zftp_chpwd
use the
contexts :zftp:zfopen
, :zftp:zfcd
, etc., depending where it was
called from. The following styles are understood:
progress
Controls the way that zftp_progress
reports on the progress of a
transfer. If empty, unset, or ‘none
’, no progress report is made; if
‘bar
’ a growing bar of inverse video is shown; if ‘percent
’ (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 $COLUMNS
parameter (normally this is
set automatically). If the size of the file being transferred is not
available, bar
and percent
meters will simply show the number of
bytes transferred so far.
When zfinit
is run, if this style is not defined for the context
:zftp:*
, it will be set to ‘bar’.
update
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 $ZFTP_TIMEOUT
.
As described for progress
, zfinit
will force this to default to 1.
remote-glob
If set to ‘1
’, ‘yes
’ or ‘true
’, filename generation (globbing) is
performed on the remote machine instead of by zsh itself; see below.
titlebar
If set to ‘1
’, ‘yes
’ or ‘true
’, zftp_chpwd
will put the remote
host and remote directory into the titlebar of terminal emulators such
as xterm or sun-cmd that allow this.
As described for progress
, zfinit
will force this to default to 1.
chpwd
If set to ‘1
’ ‘yes
’ or ‘true
’, zftp_chpwd
will call the function
chpwd
when a connection is closed. This is useful if the remote host
details were put into the terminal title bar by zftp_chpwd
and your
usual chpwd
also modifies the title bar.
When zfinit
is run, it will determine whether chpwd
exists and if so
it will set the default value for the style to 1 if none exists already.
Note that there is also an associative array zfconfig
which contains
values used by the function system. This should not be modified or
overwritten.
25.4.2 Remote globbing
The commands for retrieving files usually perform filename generation
(globbing) on their arguments; this can be turned off by passing the
option -G
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 EXTENDED_GLOB
) 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 zfcd
are much
faster.
If the remote-glob
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.
25.4.3 Automatic and temporary reopening
As described for the zfopen
command, a subsequent zfopen
with no
parameters will reopen the connection to the last host (this includes
connections made with the zfanon
command). Opened in this fashion, the
connection starts in the default remote directory and will remain open
until explicitly closed.
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 -1
option to zfopen
or zfanon
was used.
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 zfdir
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 zfdir
directly followed by a
zfget
will never close the connection automatically.
Information about the previous connection is given by the zfstat
function. So, for example, if that reports:
Session: default
Not connected.
Last session: ftp.bar.com:/pub/textfiles
then the command zfget file.txt
will attempt to reopen a connection to
ftp.bar.com
, retrieve the file /pub/textfiles/file.txt
, and
immediately close the connection again. On the other hand, zfcd ..
will open the connection in the directory /pub
and leave it open.
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.
25.4.4 Completion
Completion of local and remote files, directories, sessions and
bookmarks is supported. The older, compctl
-style completion is defined
when zfinit
is called; support for the new widget-based completion
system is provided in the function Completion/Zsh/Command/_zftp
, which
should be installed with the other functions of the completion system
and hence should automatically be available.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.
Table of Contents generated with DocToc
- 26 User Contributions
- 26.1 Description
- 26.2 Utilities
- 26.3 Remembering Recent Directories
- 26.4 Abbreviated dynamic references to directories
- 26.5 Gathering information from version control systems
- 26.6 Prompt Themes
- 26.7 ZLE Functions
- 26.8 Exception Handling
- 26.9 MIME Functions
- 26.10 Mathematical Functions
- 26.11 User Configuration Functions
- 26.12 Other Functions
26 User Contributions
26.1 Description
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.
26.2 Utilities
26.2.1 Accessing On-Line Help
The key sequence ESC h
is normally bound by ZLE to execute the
run-help
widget (see Zsh Line
Editor). This invokes the
run-help
command with the command word from the current input line as
its argument. By default, run-help
is an alias for the man
command,
so this often fails when the command word is a shell builtin or a
user-defined function. By redefining the run-help
alias, one can
improve the on-line help provided by the shell.
The helpfiles
utility, found in the Util
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 run-help
function,
found in Functions/Misc
, searches for these helpfiles and performs
several other tests to produce the most complete help possible for the
command.
Help files are installed by default to a subdirectory of
/usr/share/zsh
or /usr/local/share/zsh
.
To create your own help files with helpfiles
, choose or create a
directory where the individual command help files will reside. For
example, you might choose ~/zsh_help
. If you unpacked the zsh
distribution in your home directory, you would use the commands:
mkdir ~/zsh_help
perl ~/zsh-5.8/Util/helpfiles ~/zsh_help
The HELPDIR
parameter tells run-help
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:
HELPDIR=~/zsh_help
To use the run-help
function, you need to add lines something like the
following to your .zshrc
or equivalent startup file:
unalias run-help
autoload run-help
Note that in order for ‘autoload run-help
’ to work, the run-help
file must be in one of the directories named in your fpath
array (see
Parameters Used By The
Shell). This should
already be the case if you have a standard zsh installation; if it is
not, copy Functions/Misc/run-help
to an appropriate directory.
26.2.2 Recompiling Functions
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 zcompile
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 fpath
, zsh
won’t check whether any of its source files has changed.
The zrecompile
autoloadable function, found in Functions/Misc
, can
be used to keep function digests up to date.
zrecompile
[ -qt
] [ name
... ]
zrecompile
[ -qt
] -p
arg
... [ -``-
arg
... ]
This tries to find *.zwc
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 .zwc
file.
In the first form, each name
is the name of a compiled file or a
directory containing *.zwc
files that should be checked. If no
arguments are given, the directories and *.zwc
files in fpath
are
used.
When -t
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 -q
option quiets the chatty output
that describes what zrecompile
is doing.
Without the -t
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.
If the -p
option is given, the arg
s are interpreted as one or more
sets of arguments for zcompile
, separated by ‘-``-
’. For example:
zrecompile -p \
-R ~/.zshrc -- \
-M ~/.zcompdump -- \
~/zsh/comp.zwc ~/zsh/Completion/*/_*
This compiles ~/.zshrc
into ~/.zshrc.zwc
if that doesn’t exist or if
it is older than ~/.zshrc
. The compiled file will be marked for
reading instead of mapping. The same is done for ~/.zcompdump
and
~/.zcompdump.zwc
, but this compiled file is marked for mapping. The
last line re-creates the file ~/zsh/comp.zwc
if any of the files
matching the given pattern is newer than it.
Without the -p
option, zrecompile
does not create function digests
that do not already exist, nor does it add new functions to the digest.
The following shell loop is an example of a method for creating function
digests for all functions in your fpath
, assuming that you have write
permission to the directories:
for ((i=1; i <= $#fpath; ++i)); do
dir=$fpath[i]
zwc=${dir:t}.zwc
if [[ $dir == (.|..) || $dir == (.|..)/* ]]; then
continue
fi
files=($dir/*(N-.))
if [[ -w $dir:h && -n $files ]]; then
files=(${${(M)files%/*/*}#/})
if ( cd $dir:h &&
zrecompile -p -U -z $zwc $files ); then
fpath[i]=$fpath[i].zwc
fi
fi
done
The -U
and -z
options are appropriate for functions in the default
zsh installation fpath
; you may need to use different options for your
personal function directories.
Once the digests have been created and your fpath
modified to refer to
them, you can keep them up to date by running zrecompile
with no
arguments.
26.2.3 Keyboard Definition
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 zkbd
utility,
found in Functions/Misc
, can help you quickly create key bindings for
your configuration.
Run zkbd
either as an autoloaded function, or as a shell script:
zsh -f ~/zsh-5.8/Functions/Misc/zkbd
When you run zkbd
, 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; zkbd
warns you if it finds anything out of the
ordinary, such as a Delete key that sends neither ^H
nor ^?
.
The keystrokes read by zkbd
are recorded as a definition for an
associative array named key
, written to a file in the subdirectory
.zkbd
within either your HOME
or ZDOTDIR
directory. The name of
the file is composed from the TERM
, VENDOR
and OSTYPE
parameters,
joined by hyphens.
You may read this file into your .zshrc
or another startup file with
the ‘source
’ or ‘.
’ commands, then reference the key
parameter in
bindkey commands, like this:
source ${ZDOTDIR:-$HOME}/.zkbd/$TERM-$VENDOR-$OSTYPE
[[ -n ${key[Left]} ]] && bindkey "${key[Left]}" backward-char
[[ -n ${key[Right]} ]] && bindkey "${key[Right]}" forward-char
# etc.
Note that in order for ‘autoload zkbd
’ to work, the zkdb
file must
be in one of the directories named in your fpath
array (see
Parameters Used By The
Shell). This should
already be the case if you have a standard zsh installation; if it is
not, copy Functions/Misc/zkbd
to an appropriate directory.
26.2.4 Dumping Shell State
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 Mailing Lists), but sometimes one of the zsh developers will need to recreate your environment in order to track the problem down.
The script named reporter
, found in the Util
directory of the
distribution, is provided for this purpose. (It is also possible to
autoload reporter
, but reporter
is not installed in fpath
by
default.) This script outputs a detailed dump of the shell state, in the
form of another script that can be read with ‘zsh -f
’ to recreate that
state.
To use reporter
, read the script into your shell with the ‘.
’
command and redirect the output into a file:
. ~/zsh-5.8/Util/reporter > zsh.report
You should check the zsh.report
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.
You can also use reporter
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 aliases
, options
, and
zstyles
states may be useful because they include only changes from
the defaults. The bindings
state may be useful if you have created any
of your own keymaps, because reporter
arranges to dump the keymap
creation commands as well as the bindings for every keymap.
As is usual with automated tools, if you create a startup file with
reporter
, you should edit the results to remove unnecessary commands.
Note that if you’re using the new completion system, you should not
dump the functions
state to your startup files with reporter
; use
the compdump
function instead (see Completion
System).
-
reporter
[state
... ]
Print to standard output the indicated subset of the current shell state. The
state
arguments may be one or more of:-
all
Output everything listed below. -
aliases
Output alias definitions. -
bindings
Output ZLE key maps and bindings. -
completion
Output old-stylecompctl
commands. New completion is covered byfunctions
andzstyles
. -
functions
Output autoloads and function definitions. -
limits
Outputlimit
commands. -
options
Outputsetopt
commands. -
styles
Same aszstyles
. -
variables
Output shell parameter assignments, plusexport
commands for any environment variables. -
zstyles
Outputzstyle
commands.
If the
state
is omitted,all
is assumed.With the exception of ‘
all
’, everystate
can be abbreviated by any prefix, even a single letter; thusa
is the same asaliases
,z
is the same aszstyles
, etc. -
26.2.5 Manipulating Hook Functions
add-zsh-hook
[ -L
| -dD
] [ -Uzk
] hook
function
Several functions are special to the shell, as described in the section
Special Functions, Functions, 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
add-zsh-hook
provides a simple way of adding or removing functions
from the array.
hook
is one of chpwd
, periodic
, precmd
, preexec
,
zshaddhistory
, zshexit
, or zsh_directory_name
, the special
functions in question. Note that zsh_directory_name
is called in a
different way from the other functions, but may still be manipulated as
a hook.
function
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.
If the option -L
is given, the current values for the hook arrays are
listed with typeset
.
If the option -d
is given, the function
is removed from the array of
functions to be executed.
If the option -D
is given, the function
is treated as a pattern and
any matching names of functions are removed from the array of functions
to be executed.
The options -U
, -z
and -k
are passed as arguments to autoload
for function
. For functions contributed with zsh, the options -Uz
are appropriate.
add-zle-hook-widget
[ -L
| -dD
] [ -Uzk
] hook
widgetname
Several widget names are special to the line editor, as described in the
section Special Widgets, Widgets, 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
add-zle-hook-widget
maintains a similar array and arranges for the
special widget to invoke those additional widgets.
hook
is one of isearch-exit
, isearch-update
, line-pre-redraw
,
line-init
, line-finish
, history-line-set
, or keymap-select
,
corresponding to each of the special widgets zle-isearch-exit
, etc.
The special widget names are also accepted as the hook
argument.
widgetname
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
zle widgetname -Nw -- "$@"
Note that this means that the ‘WIDGET
’ special parameter tracks the
widgetname
when the widget function is called, rather than tracking
the name of the corresponding special hook widget.
If the option -d
is given, the widgetname
is removed from the array
of widgets to be executed.
If the option -D
is given, the widgetname
is treated as a pattern
and any matching names of widgets are removed from the array.
If widgetname
does not name an existing widget when added to the
array, it is assumed that a shell function also named widgetname
is
meant to provide the implementation of the widget. This name is
therefore marked for autoloading, and the options -U
, -z
and -k
are passed as arguments to autoload
as with add-zsh-hook
. The widget
is also created with ‘ zle -N ``widgetname
’ to cause the
corresponding function to be loaded the first time the hook is called.
The arrays of widgetname
are currently maintained in zstyle
contexts, one for each hook
context, with a style of ‘widgets
’. If
the -L
option is given, this set of styles is listed with ‘zstyle -L
’. This implementation may change, and the special widgets that
refer to the styles are created only if add-zle-hook-widget
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.
26.3 Remembering Recent Directories
The function cdr
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 pushd
,
popd
and dirs
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.
Note that the pushd
directory stack is not actually modified or used
by cdr
unless you configure it to do so as described in the
configuration section below.
26.3.1 Installation
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 add-zsh-hook
function described above:
autoload -Uz chpwd_recent_dirs cdr add-zsh-hook
add-zsh-hook chpwd chpwd_recent_dirs
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.
26.3.2 Use
All direct user interaction is via the cdr
function.
The argument to cdr is a number N
corresponding to the N
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 recent-dirs-file
style below.
If you set the recent-dirs-default
style described below cdr
will
behave the same as cd
if given a non-numeric argument, or more than
one argument. The recent directory list is updated just the same however
you change directory.
If the argument is omitted, 1 is assumed. This is similar to pushd
’s
behaviour of swapping the two most recent directories on the stack.
Completion for the argument to cdr
is available if compinit has been
run; menu selection is recommended, using:
zstyle ':completion:*:*:cdr:*:*' menu selection
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.
26.3.3 Options
The behaviour of cdr
may be modified by the following options.
-
-l
lists the numbers and the corresponding directories in abbreviated form (i.e. with~
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. -
-r
sets the variablereply
to the current set of directories. Nothing is printed and the directory is not changed. -
-e
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/
. Usually the first entry should be left as the current directory. -
-p ’``pattern``’
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.’*removeme*’
) are needed to remove entries with a given substring.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
-P
instead of-p
.
26.3.4 Configuration
Configuration is by means of the styles mechanism that should be
familiar from completion; if not, see the description of the zstyle
command in The zsh/zutil
Module. The context for
setting styles should be ’:chpwd:*’
in case the meaning of the context
is extended in future, for example:
zstyle ':chpwd:*' recent-dirs-max 0
sets the value of the recent-dirs-max
style to 0. In practice the
style name is specific enough that a context of ’*’ should be fine.
An exception is recent-dirs-insert
, which is used exclusively by the
completion system and so has the usual completion system context
(’:completion:*’
if nothing more specific is needed), though again
’*’
should be fine in practice.
-
recent-dirs-default
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 "cd". 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. -
recent-dirs-file
The file where the list of directories is saved. The default is${ZDOTDIR:-$HOME}/.chpwd-recent-dirs
, i.e. this is in your home directory unless you have set the variableZDOTDIR
to point somewhere else. Directory names are saved in$’``...``’
quoted form, so each line in the file can be supplied directly to the shell as an argument.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
+
can appear in the list to indicate the default file should be read at that point. This allows effects like the following:zstyle ':chpwd:*' recent-dirs-file \ ~/.chpwd-recent-dirs-${TTY##*/} +
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.
It is possible to use
zstyle -e
to make the directory configurable at run time: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 }
In this example, if the current directory is
~/text/writing
or a directory under it, then use a special file for saving recent directories, else use the default. -
recent-dirs-insert
Used by completion. Ifrecent-dirs-default
is true, then setting this totrue
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.If the value of the style is
always
, then only recent directories will be completed; in that case, use thecd
command when you want to complete other directories.If the value is
fallback
, recent directories will be tried first, then normal directory completion is performed if recent directory completion failed to find a match.Finally, if the value is
both
then both sets of completions are presented; the usual tag mechanism can be used to distinguish results, with recent directories tagged asrecent-dirs
. Note that the recent directories inserted are abbreviated with directory names where appropriate. -
recent-dirs-max
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. -
recent-dirs-prune
This style is an array determining what directories should (or should not) be added to the recent list. Elements of the array can include:-
parent
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. -
pattern:pattern
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,’pattern:/tmp(|/*)’
stops/tmp
or its descendants from being added. TheEXTENDED_GLOB
option is always turned on for these patterns.
-
-
recent-dirs-pushd
If set to true,cdr
will usepushd
instead ofcd
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.
26.3.5 Use with dynamic directory naming
It is possible to refer to recent directories using the dynamic
directory name syntax by using the supplied function
zsh_directory_name_cdr
a hook:
autoload -Uz add-zsh-hook
add-zsh-hook -Uz zsh_directory_name zsh_directory_name_cdr
When this is done, ~[1]
will refer to the most recent directory other
than $PWD, and so on. Completion after ~[``...
also works.
26.3.6 Details of directory handling
This section is for the curious or confused; most users will not need to know this information.
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.
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 cd -q
or pushd -q
to
avoid side effects if the change to the directory is to be invisible at
the command line. See the contents of the function chpwd_recent_dirs
for more details.
26.4 Abbreviated dynamic references to directories
The dynamic directory naming system is described in the subsection
Dynamic named directories of Filename
Expansion. In this, a reference to
~[``...``]
is expanded by a function found by the hooks mechanism.
The contributed function zsh_directory_name_generic
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.
The main feature of this function is a path-like syntax, combining abbreviations at multiple levels separated by ":". As an example, ~[g:p:s] might specify:
-
g
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
The name of a project within your git area. -
s
The source area within that project.
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.
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.
26.4.1 Usage
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.
Then arrange for the wrapper to be run as a zsh_directory_name hook:
autoload -Uz add-zsh-hook zsh_diretory_name_generic zdn_mywrapper
add-zsh-hook -U zsh_directory_name zdn_mywrapper
26.4.2 Configuration
The wrapper function should define a local associative array zdn_top.
Alternatively, this can be set with a style called mapping
. The
context for the style is :zdn:``wrapper-name
where wrapper-name
is
the function calling zsh_directory_name_generic; for example:
zstyle :zdn:zdn_mywrapper: mapping zdn_mywrapper_top
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 :default:
specifies a variable in the form /:``var
(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 zdn_top
have the same format as zdn_top
itself,
but contain relative paths.
For example,
local -A zdn_top=(
g ~/git
ga ~/alternate/git
gs /scratch/$USER/git/:second2
:default: /:second1
)
This specifies the behaviour of a directory referred to as ~[g:...]
or
~[ga:...]
or ~[gs:...]
. Later path components are optional; in that
case ~[g]
expands to ~/git
, and so on. gs
expands to
/scratch/$USER/git
and uses the associative array second2
to match
the second component; g
and ga
use the associative array second1
to match the second component.
When expanding a name to a directory, if the first component is not g
or ga
or gs
, it is not an error; the function simply returns 1 so
that a later hook function can be tried. However, matching the first
component commits the function, so if a later component does not match,
an error is printed (though this still does not stop later hooks from
being executed).
For components after the first, a relative path is expected, but note
that multiple levels may still appear. Here is an example of second1
:
local -A second1=(
p myproject
s somproject
os otherproject/subproject/:third
)
The path as found from zdn_top
is extended with the matching
directory, so ~[g:p]
becomes ~/git/myproject
. The slash between is
added automatically (it’s not possible to have a later component modify
the name of a directory already matched). Only os
specifies a variable
for a third component, and there’s no :default:
, so it’s an error to
use a name like ~[g:p:x]
or ~[ga:s:y]
because there’s nowhere to
look up the x
or y
.
The associative arrays need to be visible within this function; the
generic function therefore uses internal variable names beginning
_zdn_
in order to avoid clashes. Note that the variable reply
needs
to be passed back to the shell, so should not be local in the calling
function.
The function does not test whether directories assembled by component actually exist; this allows the system to work across automounted file systems. The error from the command trying to use a non-existent directory should be sufficient to indicate the problem.
26.4.3 Complete example
Here is a full fictitious but usable autoloadable definition of the
example function defined by the code above. So ~[gs:p:s]
expands to
/scratch/$USER/git/myscratchproject/top/srcdir
(with $USER
also
expanded).
local -A zdn_top=(
g ~/git
ga ~/alternate/git
gs /scratch/$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 "$@
It is also possible to use global associative arrays, suitably named, and set the style for the context of your wrapper function to refer to this. Then your set up code would contain the following:
typeset -A zdn_mywrapper_top=(...)
# ... and so on for other associative arrays ...
zstyle ':zdn:zdn_mywrapper:' mapping zdn_mywrapper_top
autoload -Uz add-zsh-hook zsh_directory_name_generic zdn_mywrapper
add-zsh-hook -U zsh_directory_name zdn_mywrapper
and the function zdn_mywrapper
would contain only the following:
zsh_directory_name_generic "$@"
26.5 Gathering information from version control systems
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.
In order to do that, you may use the vcs_info
function.
The following VCSs are supported, showing the abbreviated name by which they are referred to within the system:
-
Bazaar (
bzr
)
https://bazaar.canonical.com/
-
Codeville (
cdv
)
http://freecode.com/projects/codeville/
-
Concurrent Versioning System (
cvs
)
https://www.nongnu.org/cvs/
-
Darcs (
darcs
)
http://darcs.net/
-
Fossil (
fossil
)
https://fossil-scm.org/
-
Git (
git
)
https://git-scm.com/
-
GNU arch (
tla
)
https://www.gnu.org/software/gnu-arch/
-
Mercurial (
hg
)
https://www.mercurial-scm.org/
-
Monotone (
mtn
)
https://monotone.ca/
-
Perforce (
p4
)
https://www.perforce.com/
-
Subversion (
svn
)
https://subversion.apache.org/
-
SVK (
svk
)
https://svk.bestpractical.com/
There is also support for the patch management system quilt
(https://savannah.nongnu.org/projects/quilt
). See Quilt
Support below for details.
To load vcs_info
:
autoload -Uz vcs_info
It can be used in any existing prompt, because it does not require any
specific $psvar
entries to be available.
26.5.1 Quickstart
To get this feature working quickly (including colors), you can do the
following (assuming, you loaded vcs_info
properly - see above):
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~ ${vcs_info_msg_0_}%f%# '
Obviously, the last two lines are there for demonstration. You need to
call vcs_info
from your precmd
function. Once that is done you need
a single quoted ’${vcs_info_msg_0_}’
in your prompt.
To be able to use ’${vcs_info_msg_0_}’
directly in your prompt like
this, you will need to have the PROMPT_SUBST
option enabled.
Now call the vcs_info_printsys
utility from the command line:
% 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 -> git])
## they *can* be used in contexts: ':vcs_info:git-svn:*'.
git-p4
git-svn
hg-git
hg-hgsubversion
hg-hgsvn
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:
zstyle ':vcs_info:*' disable bzr cdv darcs mtn svk tla
You may also pick a few from that list and enable only those:
zstyle ':vcs_info:*' enable git cvs svn
If you rerun vcs_info_printsys
after one of these commands, you will
see the backends listed in the disable
style (or backends not in the
enable
style - if you used that) marked as disabled by a hash sign.
That means the detection of these systems is skipped completely. No
wasted time there.
26.5.2 Configuration
The vcs_info
feature can be configured via zstyle
.
First, the context in which we are working:
:vcs_info:vcs-string:user-context:repo-root-name
-
vcs-string
is one of:git
,git-svn
,git-p4
,hg
,hg-git
,hg-hgsubversion
,hg-hgsvn
,darcs
,bzr
,cdv
,mtn
,svn
,cvs
,svk
,tla
,p4
orfossil
. This is followed by ‘.quilt-``quilt-mode
’ in Quilt mode (see Quilt Support for details) and by ‘+``hook-name
’ while hooks are active (see Hooks in vcs_info for details).Currently, hooks in quilt mode don’t add the ‘
.quilt-``quilt-mode
’ information. This may change in the future. -
user-context
is a freely configurable string, assignable by the user as the first argument tovcs_info
(see its description below). -
repo-root-name
is the name of a repository in which you want a style to match. So, if you want a setting specific to/usr/src/zsh
, with that being a CVS checkout, you can setrepo-root-name
tozsh
to make it so.
There are three special values for vcs-string
: The first is named
-init-
, that is in effect as long as there was no decision what VCS
backend to use. The second is -preinit-
; it is used before
vcs_info
is run, when initializing the data exporting variables. The
third special value is formats
and is used by the vcs_info_lastmsg
for looking up its styles.
The initial value of repo-root-name
is -all-
and it is replaced with
the actual name, as soon as it is known. Only use this part of the
context for defining the formats
, actionformats
or branchformat
styles, as it is guaranteed that repo-root-name
is set up correctly
for these only. For all other styles, just use ’*’
instead.
There are two pre-defined values for user-context
:
-
default
the one used if none is specified -
command
used by vcs_info_lastmsg to lookup its styles
You can of course use ’:vcs_info:*’
to match all VCSs in all
user-contexts at once.
This is a description of all styles that are looked up.
formats
A list of formats, used when actionformats is not used (which is most of the time).
actionformats
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.
branchformat
Some backends replace %b
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.
nvcsformats
These "formats" are set when we didn’t detect a version control system
for the current directory or vcs_info
was disabled. This is useful if
you want vcs_info
to completely take over the generation of your
prompt. You would do something like PS1=’${vcs_info_msg_0_}’
to
accomplish that.
hgrevformat
hg
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 branchformat
) to include either or both. It’s only useful
when get-revision
is true. Note, the full 40-character revision id is
not available (except when using the use-simple
option) because
executing hg more than once per prompt is too slow; you may customize
this behavior using hooks.
max-exports
Defines the maximum number of vcs_info_msg_*_
variables vcs_info
will set.
enable
A list of backends you want to use. Checked in the -init-
context. If
this list contains an item called NONE
no backend is used at all and
vcs_info
will do nothing. If this list contains ALL
, vcs_info
will
use all known backends. Only with ALL
in enable
will the disable
style have any effect. ALL
and NONE
are case insensitive.
disable
A list of VCSs you don’t want vcs_info
to test for repositories
(checked in the -init-
context, too). Only used if enable
contains
ALL
.
disable-patterns
A list of patterns that are checked against $PWD
. If a pattern
matches, vcs_info
will be disabled. This style is checked in the
:vcs_info:-init-:*:-all-
context.
Say, ~/.zsh
is a directory under version control, in which you do not
want vcs_info
to be active, do:
zstyle ':vcs_info:*' disable-patterns "${(b)HOME}/.zsh(|/*)"
use-quilt
If enabled, the quilt
support code is active in ‘addon’ mode. See
Quilt Support for details.
quilt-standalone
If enabled, ‘standalone’ mode detection is attempted if no VCS is active in a given directory. See Quilt Support for details.
quilt-patch-dir
Overwrite the value of the $QUILT_PATCHES
environment variable. See
Quilt Support for details.
quiltcommand
When quilt
itself is called in quilt support, the value of this style
is used as the command name.
check-for-changes
If enabled, this style causes the %c
and %u
format escapes to show
when the working directory has uncommitted changes. The strings
displayed by these escapes can be controlled via the stagedstr
and
unstagedstr
styles. The only backends that currently support this
option are git
, hg
, and bzr
(the latter two only support
unstaged).
For this style to be evaluated with the hg
backend, the get-revision
style needs to be set and the use-simple
style needs to be unset. The
latter is the default; the former is not.
With the bzr
backend, lightweight checkouts only honor this style if
the use-server
style is set.
Note, the actions taken if this style is enabled are potentially expensive (read: they may be slow, depending on how big the current repository is). Therefore, it is disabled by default.
check-for-staged-changes
This style is like check-for-changes
, but it never checks the worktree
files, only the metadata in the .${vcs}
dir. Therefore, this style
initializes only the %c
escape (with stagedstr
) but not the %u
escape. This style is faster than check-for-changes
.
In the git
backend, this style checks for changes in the index. Other
backends do not currently implement this style.
This style is disabled by default.
stagedstr
This string will be used in the %c
escape if there are staged changes
in the repository.
unstagedstr
This string will be used in the %u
escape if there are unstaged
changes in the repository.
command
This style causes vcs_info
to use the supplied string as the command
to use as the VCS’s binary. Note, that setting this in ’:vcs_info:*
’
is not a good idea.
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. svn
is used in an
svn
repository).
The repo-root-name
part in the context is always the default -all-
when this style is looked up.
For example, this style can be used to use binaries from non-default
installation directories. Assume, git
is installed in /usr/bin but
your sysadmin installed a newer version in /usr/local/bin. Instead of
changing the order of your $PATH
parameter, you can do this:
zstyle ':vcs_info:git:*:-all-' command /usr/local/bin/git
use-server
This is used by the Perforce backend (p4
) 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 host``:``port
pair describing the server) cannot be
contacted, its name is put into the associative array
vcs_info_p4_dead_servers
and is not contacted again during the session
until it is removed by hand. If you do not set this style, the p4
backend is only usable if you have set the environment variable
P4CONFIG
to a file name and have corresponding files in the root
directories of each Perforce client. See comments in the function
VCS_INFO_detect_p4
for more detail.
The Bazaar backend (bzr
) uses this to permit contacting the server
about lightweight checkouts, see the check-for-changes
style.
use-simple
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 bzr
and
hg
backends. In the case of hg
it will invoke the external hexdump
program to parse the binary dirstate cache file; this method will not
return the local revision number.
get-revision
If set to true, vcs_info goes the extra mile to figure out the revision
of a repository’s work tree (currently for the git
and hg
backends,
where this kind of information is not always vital). For git
, the hash
value of the currently checked out commit is available via the %i
expansion. With hg
, the local revision number and the corresponding
global hash are available via %i
.
get-mq
If set to true, the hg
backend will look for a Mercurial Queue (mq
)
patch directory. Information will be available via the ‘%m
’
replacement.
get-bookmarks
If set to true, the hg
backend will try to get a list of current
bookmarks. They will be available via the ‘%m
’ replacement.
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.
use-prompt-escapes
Determines if we assume that the assembled string from vcs_info
includes prompt escapes. (Used by vcs_info_lastmsg
.)
debug
Enable debugging output to track possible problems. Currently this style
is only used by vcs_info
’s hooks system.
hooks
A list style that defines hook-function names. See Hooks in vcs_info below for details.
patch-format
nopatch-format
This pair of styles format the patch information used by the %m
expando in formats and actionformats for the git
and hg
backends.
The value is subject to certain %
-expansions described below. The
expanded value is made available in the global backend_misc
array as
${backend_misc[patches]}
(also if a set-patch-format
hook is used).
get-unapplied
This boolean style controls whether a backend should attempt to gather a list of unapplied patches (for example with Mercurial Queue patches).
Used by the quilt
and hg
backends.
The default values for these styles in all contexts are:
-
formats
" (%s)-[%b]%u%c-" -
actionformats
" (%s)-[%b|%a]%u%c-" -
branchformat
"%b:%r" (for bzr, svn, svk and hg) -
nvcsformats
"" -
hgrevformat
"%r:%h" -
max-exports
2 -
enable
ALL -
disable
(empty list) -
disable-patterns
(empty list) -
check-for-changes
false -
check-for-staged-changes
false -
stagedstr
(string: "S") -
unstagedstr
(string: "U") -
command
(empty string) -
use-server
false -
use-simple
false -
get-revision
false -
get-mq
true -
get-bookmarks
false -
use-prompt-escapes
true -
debug
false -
hooks
(empty list) -
use-quilt
false -
quilt-standalone
false -
quilt-patch-dir
empty - use$QUILT_PATCHES
-
quiltcommand
quilt -
patch-format
backend dependent
-
nopatch-format
backend dependent
-
get-unapplied
false
In normal formats
and actionformats
the following replacements are
done:
-
%s
The VCS in use (git, hg, svn, etc.). -
%b
Information about the current branch. -
%a
An identifier that describes the action. Only makes sense inactionformats
. -
%i
The current revision number or identifier. Forhg
thehgrevformat
style may be used to customize the output. -
%c
The string from thestagedstr
style if there are staged changes in the repository. -
%u
The string from theunstagedstr
style if there are unstaged changes in the repository. -
%R
The base directory of the repository. -
%r
The repository name. If%R
is/foo/bar/repoXY
,%r
isrepoXY
. -
%S
A subdirectory within a repository. If$PWD
is/foo/bar/repoXY/beer/tasty
,%S
isbeer/tasty
.
-
%m
A "misc" replacement. It is at the discretion of the backend to decide what this replacement expands to.The
hg
andgit
backends use this expando to display patch information.hg
sources patch information from themq
extensions;git
from in-progressrebase
andcherry-pick
operations and from thestgit
extension. Thepatch-format
andnopatch-format
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.The
hg
backend displays bookmark information in this expando (in addition tomq
information). See theget-mq
andget-bookmarks
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).The
quilt
‘standalone’ backend sets this expando to the same value as the%Q
expando. -
%Q
Quilt series information. When quilt is used (either in ‘addon’ mode or as a ‘standalone’ backend), this expando is set to quilt series’patch-format
string. Theset-patch-format
hook andnopatch-format
style are honoured.See Quilt Support below for details.
In branchformat
these replacements are done:
-
%b
The branch name. -
%r
The current revision number or thehgrevformat
style forhg
.
In hgrevformat
these replacements are done:
-
%r
The current local revision number. -
%h
The current global revision identifier.
In patch-format
and nopatch-format
these replacements are done:
-
%p
The name of the top-most applied patch; may be overridden by theapplied-string
hook. -
%u
The number of unapplied patches; may be overridden by theunapplied-string
hook. -
%n
The number of applied patches. -
%c
The number of unapplied patches. -
%a
The number of all patches (%a = %n + %c
). -
%g
The names of activemq
guards (hg
backend). -
%G
The number of activemq
guards (hg
backend).
Not all VCS backends have to support all replacements. For nvcsformats
no replacements are performed at all, it is just a string.
26.5.3 Oddities
If you want to use the %b
(bold off) prompt expansion in formats
,
which expands %b
itself, use %%b
. That will cause the vcs_info
expansion to replace %%b
with %b
, so that zsh’s prompt expansion
mechanism can handle it. Similarly, to hand down %b
from
branchformat
, use %%%%b
. 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.
When one of the gen-applied-string
, gen-unapplied-string
, and
set-patch-format
hooks is defined, applying %
-escaping
(‘foo=${foo//’%’/%%}
’) to the interpolated values for use in the
prompt is the responsibility of those hooks (jointly); when neither of
those hooks is defined, vcs_info
handles escaping by itself. We regret
this coupling, but it was required for backwards compatibility.
26.5.4 Quilt Support
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.
The vcs_info
integration tries to support both ways of using quilt by
having two slightly different modes of operation: ‘addon’ mode and
‘standalone’ mode).
Quilt integration is off by default; to enable it, set the use-quilt
style, and add %Q
to your formats
or actionformats
style:
zstyle ':vcs_info:*' use-quilt true
Styles looked up from the Quilt support code include
‘.quilt-``quilt-mode
’ in the vcs-string
part of the context, where
quilt-mode
is either addon
or standalone
. Example:
:vcs_info:git.quilt-addon:default:``repo-root-name
.
For ‘addon’ mode to become active vcs_info
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 ‘QUILT_PATCHES
’ environment
variable. If that variable exists its value is used, otherwise the value
‘patches
’ is assumed. The value from $QUILT_PATCHES
can be
overwritten using the ‘quilt-patches
’ style. (Note: you can use
vcs_info
to keep the value of $QUILT_PATCHES
correct all the time
via the post-quilt
hook).
When the directory in question is found, quilt is assumed to be active.
To gather more information, vcs_info
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).
If patches are applied, vcs_info
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 get-unapplied
style in the appropriate context.
vcs_info
allows for very detailed control over how the gathered
information is presented (see
Configuration and Hooks in
vcs_info), 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 stgit
for git, or mq
for
hg); the configuration for systems like that are generally configured
the same way as the quilt support.
If the quilt support is working in ‘addon’ mode, the produced string is
available as a simple format replacement (%Q
to be precise), which can
be used in formats
and actionformats
; see below for details).
If, on the other hand, the support code is working in ‘standalone’ mode,
vcs_info
will pretend as if quilt
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
‘-quilt-
’. This has implications on the used style context where
this identifier is the second element. vcs_info
will have filled in a
proper value for the "repository’s" root directory and the string
containing the information about quilt’s state will be available as the
‘misc’ replacement (and %Q
for compatibility with ‘addon’ mode).
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 vcs_info
to try and look for Quilt in
‘standalone’ mode to minimise the amount of searching on every call to
vcs_info
, there are a number of ways to do that:
Essentially, ‘standalone’ mode detection is controlled by a style called
‘quilt-standalone
’. It is a string style and its value can have
different effects. The simplest values are: ‘always
’ to run detection
every time vcs_info
is run, and ‘never
’ to turn the detection off
entirely.
If the value of quilt-standalone
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.
If the value of quilt-standalone
is an array, the elements of that
array are used as directory names under which you want the detection to
be active.
If quilt-standalone
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 ‘true
’.
Last, but not least, if the value of quilt-standalone
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.
Note, if there is both a function and a variable by the name of
quilt-standalone
, the function will take precedence.
26.5.5 Function Descriptions (Public API)
vcs_info
[user-context
]
The main function, that runs all backends and assembles all data into
${vcs_info_msg_*_}
. This is the function you want to call from
precmd
if you want to include up-to-date information in your prompt
(see Variable Description below). If an
argument is given, that string will be used instead of default
in the
user-context
field of the style context.
vcs_info_hookadd
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 ‘+vi-
’ prefix needs
to be left out here. See Hooks in vcs_info below
for details.
vcs_info_hookdel
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 ‘-a
’ is used as the first
argument, all
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 ‘+vi-
’ prefix needs to be left out here. See
Hooks in vcs_info below for details.
vcs_info_lastmsg
Outputs the last ${vcs_info_msg_*_}
value. Takes into account the
value of the use-prompt-escapes
style in
’:vcs_info:formats:command:-all-’
. It also only prints max-exports
values.
vcs_info_printsys
[user-context
]
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
disable
style.
vcs_info_setsys
Initializes vcs_info
’s internal list of available backends. With this
function, you can add support for new VCSs without restarting the shell.
All functions named VCS_INFO_*
are for internal use only.
26.5.6 Variable Description
${vcs_info_msg_``N``_}
(Note the trailing underscore)
WhereN
is an integer, e.g.,vcs_info_msg_0_
. These variables are the storage for the informational message the lastvcs_info
call has assembled. These are strongly connected to theformats
,actionformats
andnvcsformats
styles described above. Those styles are lists. The first member of that list gets expanded into${vcs_info_msg_0_}
, the second into${vcs_info_msg_1_}
and the Nth into${vcs_info_msg_N-1_}
. (See themax-exports
style above.)
All variables named VCS_INFO_*
are for internal use only.
26.5.7 Hooks in vcs_info
Hooks are places in vcs_info
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.
For configuration, hooks change the style context:
:vcs_info:vcs-string+hook-name:user-context:repo-root-name
To register functions to a hook, you need to list them in the hooks
style in the appropriate context.
Example:
zstyle ':vcs_info:*+foo:*' hooks bar baz
This registers functions to the hook ‘foo’ for all backends. In order to
avoid namespace problems, all registered function names are prepended by
a ‘+vi-
’, so the actual functions called for the ‘foo’ hook are
‘+vi-bar
’ and ‘+vi-baz
’.
If you would like to register a function to a hook regardless of the
current context, you may use the vcs_info_hookadd
function. To remove
a function that was added like that, the vcs_info_hookdel
function can
be used.
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.
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 before
statically registered ones (the ones added by
vcs_info_hookadd
).
You may pass data between functions via an associative array,
user_data
. For example:
+vi-git-myfirsthook(){
user_data[myval]=$myval
}
+vi-git-mysecondhook(){
# do something with ${user_data[myval]}
}
There are a number of variables that are special in hook contexts:
-
ret
The return value that the hooks system will return to the caller. The default is an integer ‘zero’. If and how a changedret
value changes the execution of the caller depends on the specific hook. See the hook documentation below for details. -
hook_com
An associated array which is used for bidirectional communication from the caller to hook functions. The used keys depend on the specific hook. -
context
The active context of the hook. Functions that wish to change this variable should make it local scope first. -
vcs
The current VCS after it was detected. The same values as in the enable/disable style are used. Available in all hooks exceptstart-up
.
Finally, the full list of currently available hooks:
-
start-up
Called after startingvcs_info
but before the VCS in this directory is determined. It can be used to deactivatevcs_info
temporarily if necessary. Whenret
is set to1
,vcs_info
aborts and does nothing; when set to2
,vcs_info
sets up everything as if no version control were active and exits. -
pre-get-data
Same asstart-up
but after the VCS was detected. -
gen-hg-bookmark-string
Called in the Mercurial backend when a bookmark string is generated; theget-revision
andget-bookmarks
styles must be true.This hook gets the names of the Mercurial bookmarks that
vcs_info
collected from ‘hg’.If a bookmark is active, the key
${hook_com[hg-active-bookmark]}
is set to its name. The key is otherwise unset.When setting
ret
to non-zero, the string in${hook_com[hg-bookmark-string]}
will be used in the%m
escape informats
andactionformats
and will be available in the globalbackend_misc
array as${backend_misc[bookmarks]}
. -
gen-applied-string
Called in thegit
(withstgit
or during rebase or merge), andhg
(withmq
) backends and inquilt
support when theapplied-string
is generated; theuse-quilt
zstyle must be true forquilt
(themq
andstgit
backends are active by default).This hook gets the names of all applied patches which
vcs_info
collected so far in the opposite order, which means that the first argument is the top-most patch and so forth.When setting
ret
to non-zero, the string in${hook_com[applied-string]}
will be available as%p
in thepatch-format
andnopatch-format
styles. This hook is, in concert withset-patch-format
, responsible for%
-escaping that value for use in the prompt. (See Oddities.) -
gen-unapplied-string
Called in thegit
(withstgit
or during rebase), andhg
(withmq
) backend and inquilt
support when theunapplied-string
is generated; theget-unapplied
style must be true.This hook gets the names of all unapplied patches which
vcs_info
collected so far in order, which means that the first argument is the patch next-in-line to be applied and so forth.When setting
ret
to non-zero, the string in${hook_com[unapplied-string]}
will be available as%u
in thepatch-format
andnopatch-format
styles. This hook is, in concert withset-patch-format
, responsible for%
-escaping that value for use in the prompt. (See Oddities.) -
gen-mqguards-string
Called in thehg
backend whenguards-string
is generated; theget-mq
style must be true (default).This hook gets the names of any active
mq
guards.When setting
ret
to non-zero, the string in${hook_com[guards-string]}
will be used in the%g
escape in thepatch-format
andnopatch-format
styles. -
no-vcs
This hooks is called when no version control system was detected.The ‘
hook_com
’ parameter is not used. -
post-backend
Called as soon as the backend has finished collecting information.The ‘
hook_com
’ keys available are as for theset-message
hook. -
post-quilt
Called after thequilt
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"-nopc-"
if that directory wasn’t found.The ‘hook_com’ parameter is not used.
-
set-branch-format
Called before ‘branchformat
’ is set. The only argument to the hook is the format that is configured at this point.The ‘
hook_com
’ keys considered are ‘branch
’ and ‘revision
’. They are set to the values figured out so far byvcs_info
and any change will be used directly when the actual replacement is done.If
ret
is set to non-zero, the string in${hook_com[branch-replace]}
will be used unchanged as the ‘%b
’ replacement in the variables set byvcs_info
. -
set-hgrev-format
Called before a ‘hgrevformat
’ is set. The only argument to the hook is the format that is configured at this point.The ‘
hook_com
’ keys considered are ‘hash
’ and ‘localrev
’. They are set to the values figured out so far byvcs_info
and any change will be used directly when the actual replacement is done.If
ret
is set to non-zero, the string in${hook_com[rev-replace]}
will be used unchanged as the ‘%i
’ replacement in the variables set byvcs_info
. -
pre-addon-quilt
This hook is used whenvcs_info
’s quilt functionality is active in "addon" mode (quilt used on top of a real version control system). It is activated right before any quilt specific action is taken.Setting the ‘
ret
’ variable in this hook to a non-zero value avoids any quilt specific actions from being run at all. -
set-patch-format
This hook is used to control some of the possible expansions inpatch-format
andnopatch-format
styles with patch queue systems such as quilt, mqueue and the like.This hook is used in the
git
,hg
andquilt
backends.The hook allows the control of the
%p
(${hook_com[applied]}
) and%u
(${hook_com[unapplied]}
) expansion in all backends that use the hook. With the mercurial backend, the%g
(${hook_com[guards]}
) expansion is controllable in addition to that.If
ret
is set to non-zero, the string in${hook_com[patch-replace]}
will be used unchanged instead of an expanded format frompatch-format
ornopatch-format
.This hook is, in concert with the
gen-applied-string
orgen-unapplied-string
hooks if they are defined, responsible for%
-escaping the finalpatch-format
value for use in the prompt. (See Oddities.) -
set-message
Called each time before a ‘vcs_info_msg_``N``_
’ message is set. It takes two arguments; the first being the ‘N
’ in the message variable name, the second is the currently configuredformats
oractionformats
.There are a number of ‘
hook_com
’ keys, that are used here: ‘action
’, ‘branch
’, ‘base
’, ‘base-name
’, ‘subdir
’, ‘staged
’, ‘unstaged
’, ‘revision
’, ‘misc
’, ‘vcs
’ and one ‘miscN
’ entry for each backend-specific data field (N
starting at zero). They are set to the values figured out so far byvcs_info
and any change will be used directly when the actual replacement is done.Since this hook is triggered multiple times (once for each configured
formats
oractionformats
), each of the ‘hook_com
’ keys mentioned above (except for themiscN
entries) has an ‘_orig
’ counterpart, so even if you changed a value to your liking you can still get the original value in the next run. Changing the ‘_orig
’ values is probably not a good idea.If
ret
is set to non-zero, the string in${hook_com[message]}
will be used unchanged as the message byvcs_info
.
If all of this sounds rather confusing, take a look at
Examples and also in the
Misc/vcs_info-examples
file in the Zsh source. They contain some
explanatory code.
26.5.8 Examples
Don’t use vcs_info
at all (even though it’s in your prompt):
zstyle ':vcs_info:*' enable NONE
Disable the backends for bzr
and svk
:
zstyle ':vcs_info:*' disable bzr svk
Disable everything but bzr
and svk
:
zstyle ':vcs_info:*' enable bzr svk
Provide a special formats for git
:
zstyle ':vcs_info:git:*' formats ' GIT, BABY! [%b]'
zstyle ':vcs_info:git:*' actionformats ' GIT ACTION! [%b|%a]'
All %x
expansion in all sorts of formats (formats
, actionformats
,
branchformat
, you name it) are done using the ‘zformat
’ builtin from
the ‘zsh/zutil
’ module. That means you can do everything with these
%x
items what zformat supports. In particular, if you want something
that is really long to have a fixed width, like a hash in a mercurial
branchformat, you can do this: %12.12i
. That’ll shrink the 40
character hash to its 12 leading characters. The form is actually
‘%``min``.``max``x
’. More is possible. See The zsh/zutil
Module for details.
Use the quicker bzr
backend
zstyle ':vcs_info:bzr:*' use-simple true
If you do use use-simple
, please report if it does
‘the-right-thing[tm]’.
Display the revision number in yellow for bzr
and svn
:
zstyle ':vcs_info:(svn|bzr):*' \
branchformat '%b%{'${fg[yellow]}'%}:%r'
If you want colors, make sure you enclose the color codes in
%{``...``%}
if you want to use the string provided by vcs_info
in
prompts.
Here is how to print the VCS information as a command (not in a prompt):
alias vcsi='vcs_info command; vcs_info_lastmsg'
This way, you can even define different formats for output via
vcs_info_lastmsg
in the ’:vcs_info:*:command:*
’ namespace.
Now as promised, some code that uses hooks: say, you’d like to replace
the string ‘svn’ by ‘subversion’ in vcs_info
’s %s
formats
replacement.
First, we will tell vcs_info
to call a function when populating the
message variables with the gathered information:
zstyle ':vcs_info:*+set-message:*' hooks svn2subversion
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 ‘debug
’ style:
zstyle ':vcs_info:*+*:*' debug true
That should give you an idea what is going on. Specifically, the
function that we are looking for is ‘+vi-svn2subversion
’. Note, the
‘+vi-
’ prefix. So, everything is in order, just as documented. When
you are done checking out the debugging output, disable it again:
zstyle ':vcs_info:*+*:*' debug false
Now, let’s define the function:
function +vi-svn2subversion() {
[[ ${hook_com[vcs_orig]} == svn ]] && hook_com[vcs]=subversion
}
Simple enough. And it could have even been simpler, if only we had
registered our function in a less generic context. If we do it only in
the ‘svn
’ backend’s context, we don’t need to test which the active
backend is:
zstyle ':vcs_info:svn+set-message:*' hooks svn2subversion
function +vi-svn2subversion() {
hook_com[vcs]=subversion
}
And finally a little more elaborate example, that uses a hook to create
a customised bookmark string for the hg
backend.
Again, we start off by registering a function:
zstyle ':vcs_info:hg+gen-hg-bookmark-string:*' hooks hgbookmarks
And then we define the ‘+vi-hgbookmarks
’ function:
function +vi-hgbookmarks() {
# The default is to connect all bookmark names by
# commas. This mixes things up a little.
# Imagine, there's one type of bookmarks that is
# special to you. Say, because it's *your* work.
# Those bookmarks look always like this: "sh/*"
# (because your initials are sh, for example).
# This makes the bookmarks string use only those
# bookmarks. If there's more than one, it
# concatenates them using commas.
# The bookmarks returned by `hg' are available in
# the function's positional parameters.
local s="${(Mj:,:)@:#sh/*}"
# 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
}
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.
This concludes our guided tour through zsh’s vcs_info
.
26.6 Prompt Themes
26.6.1 Installation
You should make sure all the functions from the Functions/Prompts
directory of the source distribution are available; they all begin with
the string ‘prompt_
’ except for the special function‘promptinit
’.
You also need the ‘colors
’ and ‘add-zsh-hook
’ functions from
Functions/Misc
. 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 fpath
array (this should
already be the case if they were installed), and at least the function
promptinit
should be autoloaded; it will autoload the rest. Finally,
to initialize the use of the system you need to call the promptinit
function. The following code in your .zshrc
will arrange for this;
assume the functions are stored in the directory ~/myfns
:
fpath=(~/myfns $fpath)
autoload -U promptinit
promptinit
26.6.2 Theme Selection
Use the prompt
command to select your preferred theme. This command
may be added to your .zshrc
following the call to promptinit
in
order to start zsh with a theme already selected.
-
prompt
[-c
|-l
]
prompt
[-p
|-h
] [theme
... ]
prompt
[-s
]theme
[arg
... ]
Set or examine the prompt theme. With no options and atheme
argument, the theme with that name is set as the current theme. The available themes are determined at run time; use the-l
option to see a list. The specialtheme
‘random
’ selects at random one of the available themes and sets your prompt to that.In some cases the
theme
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.Options are:
-
-c
Show the currently selected theme and its parameters, if any. -
-l
List all available prompt themes. -
-p
Preview the theme named bytheme
, or all themes if notheme
is given. -
-h
Show help for the theme named bytheme
, or for theprompt
function if notheme
is given. -
-s
Settheme
as the current theme and save state.
-
-
prompt_``theme``_setup
Each availabletheme
has a setup function which is called by theprompt
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.
26.6.3 Utility Themes
-
prompt off
The theme ‘off
’ sets all the prompt variables to minimal values with no special effects. -
prompt default
The theme ‘default
’ sets all prompt variables to the same state as if an interactive zsh was started with no initialization files. -
prompt restore
The special theme ‘restore
’ erases all theme settings and sets prompt variables to their state before the first time the ‘prompt
’ function was run, provided each theme has properly defined its cleanup (see below).Note that you can undo ‘
prompt off
’ and ‘prompt default
’ with ‘prompt restore
’, but a second restore does not undo the first.
26.6.4 Writing Themes
The first step for adding your own theme is to choose a name for it, and
create a file ‘prompt_name_setup
’ in a directory in your fpath
, such
as ~/myfns
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 PS1
, PS2
, RPS1
, etc., rather than the
longer PROMPT
and RPROMPT
.
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:
-
Assign
prompt_opts
The arrayprompt_opts
may be assigned any of"bang"
,"cr"
,"percent"
,"sp"
, and/or"subst"
as values. The corresponding setopts (promptbang
, etc.) are turned on, all other prompt-related options are turned off. Theprompt_opts
array preserves setopts even beyond the scope oflocaloptions
, should your function need that. -
Modify precmd and preexec
Use ofadd-zsh-hook
is recommended. Theprecmd
andpreexec
hooks are automatically adjusted if the prompt theme changes or is disabled. -
Declare cleanup
If your function makes any other changes that should be undone when the theme is disabled, your setup function may callprompt_cleanup command
where
command
should be suitably quoted. If your theme is ever disabled or replaced by another,command
is executed witheval
. You may declare more than one such cleanup hook. -
Define preview
Define or autoload a functionprompt_name_preview
to display a simulated version of your prompt. A simple default previewer is defined bypromptinit
for themes that do not define their own. This preview function is called by ‘prompt -p
’. -
Provide help
Define or autoload a functionprompt_name_help
to display documentation or help text for your theme. This help function is called by ‘prompt -h
’.
26.7 ZLE Functions
26.7.1 Widgets
These functions all implement user-defined ZLE widgets (see Zsh Line
Editor) which can be bound to
keystrokes in interactive shells. To use them, your .zshrc
should
contain lines of the form
autoload function
zle -N function
followed by an appropriate bindkey
command to associate the function
with a key sequence. Suggested bindings are described below.
-
bash-style word functions
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:autoload -U select-word-style select-word-style bash
-
forward-word-match
,backward-word-match
kill-word-match
,backward-kill-word-match
transpose-words-match
,capitalize-word-match
up-case-word-match
,down-case-word-match
delete-whole-word-match
,select-word-match
select-word-style
,match-word-context
,match-words-by-style
The first eight ‘-match
’ 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 functionselect-word-style
, the way words are matched can be altered.select-word-match
is intended to be used as a text object in vi mode but with custom word styles. For comparison, the widgets described in Text Objects use fixed definitions of words, compatible with thevim
editor.The simplest way of configuring the functions is to use
select-word-style
, 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-match
functions will automatically replace the builtin versions, so they do not need to be loaded explicitly.The word styles available are as follows. Only the first character is examined.
-
bash
Word characters are alphanumeric characters only. -
normal
As in normal shell operation: word characters are alphanumeric characters plus any characters present in the string given by the parameter$WORDCHARS
. -
shell
Words are complete shell command arguments, possibly including complete quoted strings, or any tokens special to the shell. -
whitespace
Words are any set of characters delimited by whitespace. -
default
Restore the default settings; this is usually the same as ‘normal
’.
All but ‘
default
’ 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 stylesubword-range
can supply an alternative character range to the default ‘[:upper:]
’; the value of the style is treated as the contents of a ‘[``...``]
’ pattern (note that the outer brackets should not be supplied, only those surrounding named ranges).More control can be obtained using the
zstyle
command, as described in The zsh/zutil Module. Each style is looked up in the context:zle:``widget
wherewidget
is the name of the user-defined widget, not the name of the function implementing it, so in the case of the definitions supplied byselect-word-style
the appropriate contexts are:zle:forward-word
, and so on. The functionselect-word-style
itself always defines styles for the context ‘:zle:*
’ which can be overridden by more specific (longer) patterns as well as explicit contexts.The style
word-style
specifies the rules to use. This may have the following values.-
normal
Use the standard shell rules, i.e. alphanumerics and$WORDCHARS
, unless overridden by the stylesword-chars
orword-class
. -
specified
Similar tonormal
, but only the specified characters, and not also alphanumerics, are considered word characters. -
unspecified
The negation of specified. The given characters are those which will not be considered part of a word. -
shell
Words are obtained by using the syntactic rules for generating shell command arguments. In addition, special tokens which are never command arguments such as ‘()
’ are also treated as words. -
whitespace
Words are whitespace-delimited strings of characters.
The first three of those rules usually use
$WORDCHARS
, but the value in the parameter can be overridden by the styleword-chars
, which works in exactly the same way as$WORDCHARS
. In addition, the styleword-class
uses character class syntax to group characters and takes precedence overword-chars
if both are set. Theword-class
style does not include the surrounding brackets of the character class; for example, ‘-:[:alnum:]
’ is a validword-class
to include all alphanumerics plus the characters ‘-
’ and ‘:
’. Be careful including ‘]
’, ‘^
’ and ‘-
’ as these are special inside character classes.word-style
may also have ‘-subword
’ appended to its value to turn on subword matching, as described above.The style
skip-chars
is mostly useful fortranspose-words
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, ifzstyle ':zle:transpose-words' skip-chars 1
has been set, and
transpose-words-match
is called with the cursor on theX
offoo``X``bar
, whereX
can be any character, then the resulting expression isbar``X``foo
.Finer grained control can be obtained by setting the style
word-context
to an array of pairs of entries. Each pair of entries consists of apattern
and asubcontext
. The shell argument the cursor is on is matched against eachpattern
in turn until one matches; if it does, the context is extended by a colon and the correspondingsubcontext
. 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 stringbetween
the word is set to a single space; else if it is contains the stringback
, the word before the cursor is considered, else the word after cursor is considered. Some examples are given below.The style
skip-whitespace-first
is only used with theforward-word
widget. If it is set to true, thenforward-word
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 usingselect-word-style
the widget is set in the context:zle:*
totrue
if the word style isbash
andfalse
otherwise. It may be overridden by setting it in the more specific context:zle:forward-word*
.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
backward-kill-space-word
usingbackward-kill-word-match
, the generic widget implementingbackward-kill-word
behaviour, and ensures that the new widget always implements space-delimited behaviour.zle -N backward-kill-space-word backward-kill-word-match zstyle :zle:backward-kill-space-word word-style space
The widget
backward-kill-space-word
can now be bound to a key.Here are some further examples of use of the styles, actually taken from the simplified interface in
select-word-style
:zstyle ':zle:*' word-style standard zstyle ':zle:*' word-chars ''
Implements bash-style word handling for all widgets, i.e. only alphanumerics are word characters; equivalent to setting the parameter
WORDCHARS
empty for the given context.style ':zle:*kill*' word-style space
Uses space-delimited words for widgets with the word ‘kill’ in the name. Neither of the styles
word-chars
norword-class
is used in this case.Here are some examples of use of the
word-context
style to extend the context.zstyle ':zle:*' word-context \ "*/*" filename "[[:space:]]" whitespace zstyle ':zle:transpose-words:whitespace' word-style shell zstyle ':zle:transpose-words:filename' word-style normal zstyle ':zle:transpose-words:filename' word-chars ''
This provides two different ways of using
transpose-words
depending on whether the cursor is on whitespace between words or on a filename, here any word containing a/
. 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:zle:transpose-words
.The word matching and all the handling of
zstyle
settings is actually implemented by the functionmatch-words-by-style
. This can be used to create new user-defined widgets. The calling function should set the local parametercurcontext
to:zle:``widget
, create the local parametermatched_words
and callmatch-words-by-style
with no arguments. On return,matched_words
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 theskip-chars
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.If the variable
matched_words
is defined by the caller tomatch-words-by-style
as an associative array (local -A matched_words
), then the seven values given above should be retrieved from it as elements namedstart
,word-before-cursor
,ws-before-cursor
,ws-after-cursor
,word-after-cursor
,ws-after-word
, andend
. In addition the elementis-word-start
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 thews-after-cursor
element) and 0 otherwise. This form is recommended for future compatibility.It is possible to pass options with arguments to
match-words-by-style
to override the use of styles. The options are:-
-w
word-style
-
-s
skip-chars
-
-c
word-class
-
-C
word-chars
-
-r
subword-range
For example,
match-words-by-style -w shell -c 0
may be used to extract the command argument around the cursor.The
word-context
style is implemented by the functionmatch-word-context
. This should not usually need to be called directly. -
-
bracketed-paste-magic
Thebracketed-paste
widget (see Miscellaneous in Widgets) 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 contributedurl-quote-magic
widget described below.The
bracketed-paste-magic
widget is meant to replacebracketed-paste
with a wrapper that re-enables these self-insert actions, and other actions as selected by zstyles. Therefore this widget is installed withautoload -Uz bracketed-paste-magic zle -N bracketed-paste bracketed-paste-magic
Other than enabling some widget processing,
bracketed-paste-magic
attempts to replicatebracketed-paste
as faithfully as possible.The following zstyles may be set to control processing of pasted text. All are looked up in the context ‘
:bracketed-paste-magic
’.-
active-widgets
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 ‘self-*
’ so any user-defined widgets named with that prefix are active along with the builtin self-insert.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 ‘
undefined-key
’, any unknown sequences are discarded from the pasted text. -
inactive-keys
The inverse ofactive-widgets
, a list of key sequences that always useself-insert-unmeta
even when bound to an active widget. Note that this is a list of literal key sequences, not patterns. -
paste-init
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 ‘PASTED
’ contains the initial state of the pasted text. All other ZLE parameters such as ‘BUFFER
’ have their normal values and side-effects, and full history is available, so for examplepaste-init
functions may move words fromBUFFER
intoPASTED
to make those words visible to theactive-widgets
.A non-zero return from a
paste-init
function does not prevent the paste itself from proceeding.Loading
bracketed-paste-magic
definesbackward-extend-paste
, a helper function for use inpaste-init
.zstyle :bracketed-paste-magic paste-init \ backward-extend-paste
When a paste would insert into the middle of a word or append text to a word already on the line,
backward-extend-paste
moves the prefix fromLBUFFER
intoPASTED
so that theactive-widgets
see the full word so far. This may be useful withurl-quote-magic
. -
paste-finish
Another list of function names called in order until one returns non-zero. These functions are called after the pasted text has been processed by theactive-widgets
, but before it is inserted into ‘BUFFER
’. ZLE parameters have their normal values and side-effects.A non-zero return from a
paste-finish
function does not prevent the paste itself from proceeding.Loading
bracketed-paste-magic
also definesquote-paste
, a helper function for use inpaste-finish
.zstyle :bracketed-paste-magic paste-finish \ quote-paste zstyle :bracketed-paste-magic:finish quote-style \ qqq
When the pasted text is inserted into
BUFFER
, it is quoted per thequote-style
value. To forcibly turn off the built-in numeric prefix quoting ofbracketed-paste
, use:zstyle :bracketed-paste-magic:finish quote-style \ none
Important: During
active-widgets
processing of the paste (afterpaste-init
and beforepaste-finish
),BUFFER
starts empty and history is restricted, so cursor motions, etc., may not pass outside of the pasted content. Text assigned toBUFFER
by the active widgets is copied back intoPASTED
beforepaste-finish
. -
-
copy-earlier-word
This widget works like a combination ofinsert-last-word
andcopy-prev-shell-word
. Repeated invocations of the widget retrieve earlier words on the relevant history line. With a numeric argumentN
, insert theN
th word from the history line;N
may be negative to count from the end of the line.If
insert-last-word
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.Otherwise, the widget applies to words on the line currently being edited. The
widget
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 asinsert-last-word
. -
cycle-completion-positions
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.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.
-
delete-whole-word-match
This is another function which works like the-match
functions described immediately above, i.e. using styles to decide the word boundaries. However, it is not a replacement for any existing function.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
kill
, the removed text will be placed in the cutbuffer for future yanking. This can be obtained by definingkill-whole-word-match
as follows:zle -N kill-whole-word-match delete-whole-word-match
and then binding the widget
kill-whole-word-match
. -
up-line-or-beginning-search
,down-line-or-beginning-search
These widgets are similar to the builtin functionsup-line-or-search
anddown-line-or-search
: 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 ofhistory-beginning-search-backward
and-forward
, rather than the first word on the line. -
edit-command-line
Edit the command line using your visual editor, as inksh
.bindkey -M vicmd v edit-command-line
-
expand-absolute-path
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. -
history-search-end
This function implements the widgetshistory-beginning-search-backward-end
andhistory-beginning-search-forward-end
. These commands work by first calling the corresponding builtin widget (see History Control) 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.Although you
autoload
only one function, the commands to use it are slightly different because it implements two widgets.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
-
history-beginning-search-menu
This function implements yet another form of history searching. The text before the cursor is used to select lines from the history, as forhistory-beginning-search-backward
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.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.
If the widget name contains ‘
-end
’ the cursor is moved to the end of the line inserted. If the widget name contains ‘-space
’ 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:zle -N history-beginning-search-menu-space-end \ history-beginning-search-menu
-
history-pattern-search
The functionhistory-pattern-search
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^
to anchor the search to the start of the line, and the last character may be$
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.The commands to create bindable widgets are similar to those in the example immediately above:
autoload -U history-pattern-search zle -N history-pattern-search-backward history-pattern-search zle -N history-pattern-search-forward history-pattern-search
-
incarg
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 parameterincarg
may be set to change the default increment to something other than one.bindkey '^X+' incarg
-
incremental-complete-word
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^H
orDEL
. Pressing return accepts the completion so far and returns you to normal editing (that is, the command line is not immediately executed). You can hitTAB
to do normal completion,^G
to abort back to the state when you started, and^D
to list the matches.This works only with the new function based completion system.
bindkey '^Xi' incremental-complete-word
-
insert-composed-char
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 examplehttp://www.faqs.org/rfcs/rfc1345.html
).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,
insert-composed-char a:
can be used within a widget to insert an a with umlaut into the command line. This has the advantages over use of aFor best results zsh should have been built with support for multibyte characters (configured with
–enable-multibyte
); however, the function works for the limited range of characters available in single-byte character sets such as ISO-8859-1.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
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.
See
insert-unicode-char
for an alternative way of inserting Unicode characters using their hexadecimal character number.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
define-composed-chars
. Please send any additions tozsh-workers@zsh.org
.The codes for the second character when used to accent the first are as follows. Note that not every character can take every accent.
-
!
Grave. -
’
Acute. -
>
Circumflex. -
?
Tilde. (This is not~
as RFC 1345 does not assume that character is present on the keyboard.) -
-
Macron. (A horizontal bar over the base character.) -
(
Breve. (A shallow dish shape over the base character.) -
.
Dot above the base character, or in the case ofi
no dot, or in the case ofL
andl
a centered dot. -
:
Diaeresis (Umlaut). -
c
Cedilla. -
_
Underline, however there are currently no underlined characters. -
/
Stroke through the base character. -
"
Double acute (only supported on a few letters). -
;
Ogonek. (A little forward facing hook at the bottom right of the character.) -
<
Caron. (A little v over the letter.) -
0
Circle over the base character. -
2
Hook over the base character. -
9
Horn over the base character.
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
!
to~
(0x21 to 0x7e) by preceding the character with^
, for example^A
for a double-widthA
.The following other two-character sequences are understood.
-
ASCII characters
These are already present on most keyboards:-
<(
Left square bracket -
//
Backslash (solidus) -
)>
Right square bracket -
(!
Left brace (curly bracket) -
!!
Vertical bar (pipe symbol) -
!)
Right brace (curly bracket) -
’?
Tilde
-
-
Special letters
Characters found in various variants of the Latin alphabet:-
ss
Eszett (scharfes S) -
D-
,d-
Eth -
TH
,th
Thorn -
kk
Kra -
’n
’n -
NG
,ng
Ng -
OI
,oi
Oi -
yr
yr -
ED
ezh
-
-
Currency symbols
-
Ct
Cent -
Pd
Pound sterling (also lira and others) -
Cu
Currency -
Ye
Yen -
Eu
Euro (N.B. not in RFC 1345)
-
-
Punctuation characters
References to "right" quotes indicate the shape (like a 9 rather than 6) rather than their grammatical use. (For example, a "right" low double quote is used to open quotations in German.)-
!I
Inverted exclamation mark -
BB
Broken vertical bar -
SE
Section -
Co
Copyright -
-a
Spanish feminine ordinal indicator -
<<
Left guillemet -
-``-
Soft hyphen -
Rg
Registered trade mark -
PI
Pilcrow (paragraph) -
-o
Spanish masculine ordinal indicator -
>>
Right guillemet -
?I
Inverted question mark -
-1
Hyphen -
-N
En dash -
-M
Em dash -
-3
Horizontal bar -
:3
Vertical ellipsis -
.3
Horizontal midline ellipsis -
!2
Double vertical line -
=2
Double low line -
’6
Left single quote -
’9
Right single quote -
.9
"Right" low quote -
9’
Reversed "right" quote -
"6
Left double quote -
"9
Right double quote -
:9
"Right" low double quote -
9"
Reversed "right" double quote -
/-
Dagger -
/=
Double dagger
-
-
Mathematical symbols
-
DG
Degree -
-2
,+-
,-+
- sign, +/- sign, -/+ sign -
2S
Superscript 2 -
3S
Superscript 3 -
1S
Superscript 1 -
My
Micro -
.M
Middle dot -
14
Quarter -
12
Half -
34
Three quarters -
*X
Multiplication -
-:
Division -
%0
Per mille -
FA
,TE
,/0
For all, there exists, empty set -
dP
,DE
,NB
Partial derivative, delta (increment), del (nabla) -
(-
,-)
Element of, contains -
*P
,+Z
Product, sum -
*-
,Ob
,Sb
Asterisk, ring, bullet -
RT
,0(
,00
Root sign, proportional to, infinity
-
-
Other symbols
-
cS
,cH
,cD
,cC
Card suits: spades, hearts, diamonds, clubs -
Md
,M8
,M2
,Mb
,Mx
,MX
Musical notation: crotchet (quarter note), quaver (eighth note), semiquavers (sixteenth notes), flag sign, natural sign, sharp sign -
Fm
,Ml
Female, male
-
-
Accents on their own
-
’>
Circumflex (same as caret,^
) -
’!
Grave (same as backtick,‘
) -
’,
Cedilla -
’:
Diaeresis (Umlaut) -
’m
Macron -
”
Acute
-
-
-
insert-files
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.bindkey '^Xf' insert-files
-
insert-unicode-char
When first executed, the user inputs a set of hexadecimal digits. This is terminated with another call toinsert-unicode-char
. The digits are then turned into the corresponding Unicode character. For example, if the widget is bound to^XU
, the character sequence ‘^XU 4 c ^XU
’ insertsL
(Unicode U+004c).See
insert-composed-char
for a way of inserting characters using a two-character mnemonic. -
narrow-to-region
[-p
pre
] [-P
post
]
-S
statepm
|-R
statepm
| [-l
lbufvar
] [-r
rbufvar
] ]
-n
] [start
end
]
narrow-to-region-invisible
predict-on
This set of functions implements predictive typing using history search. Afterpredict-on
, typing characters causes the editor to look backward in the history for the first line beginning with what you have typed so far. Afterpredict-off
, editing returns to normal for the line found. In fact, you often don’t even need to usepredict-off
, 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 thetoggle
style below.With the function based completion system (which is needed for this), you should be able to type
TAB
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.The first time
predict-on
is used, it creates several additional widget functions:-
delete-backward-and-predict
Replaces thebackward-delete-char
widget. You do not need to bind this yourself. -
insert-and-predict
Implements predictive typing by replacing theself-insert
widget. You do not need to bind this yourself. -
predict-off
Turns off predictive typing.
Although you
autoload
only thepredict-on
function, it is necessary to create a keybinding forpredict-off
as well.zle -N predict-on zle -N predict-off bindkey '^X^Z' predict-on bindkey '^Z' predict-off
-
-
read-from-minibuffer
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,execute-named-cmd
). The value is then returned to the calling function in the parameter$REPLY
and the editing buffer restored to its previous state. If the read was aborted by a keyboard break (typically^G
), the function returns status 1 and$REPLY
is not set.If one argument is supplied to the function it is taken as a prompt, otherwise ‘
?
’ is used. If two arguments are supplied, they are the prompt and the initial value of$LBUFFER
, and if a third argument is given it is the initial value of$RBUFFER
. This provides a default value and starting cursor placement. Upon return the entire buffer is the value of$REPLY
.One option is available: ‘
-k
num
’ specifies thatnum
characters are to be read instead of a whole line. The line editor is not invoked recursively in this case, so depending on the terminal settings the input may not be visible, and only the input keys are placed in$REPLY
, not the entire buffer. Note that unlike theread
builtinnum
must be given; there is no default.The name is a slight misnomer, as in fact the shell’s own minibuffer is not used. Hence it is still possible to call
executed-named-cmd
and similar functions while reading a value. -
replace-argument
,replace-argument-edit
The functionreplace-argument
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,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.
If no numeric argument is given, the current argument is replaced; this is the last argument if the previous history line is being used.
The function prompts for a replacement argument.
If the widget contains the string
edit
, for example is defined aszle -N replace-argument-edit replace-argument
then the function presents the current value of the argument for editing, otherwise the editing buffer for the replacement is initially empty.
-
replace-string
,replace-pattern
replace-string-again
,replace-pattern-again
The functionreplace-string
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.If the widget name contains the word ‘
pattern
’, for example by defining the widget using the command ‘zle -N replace-pattern replace-string
’, 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 ‘&
’ in the replacement string will be replaced with the matched source string, and a backquoted digit ‘\``N
’ will be replaced by theN
th parenthesised expression matched. The form ‘\{``N``}
’ may be used to protect the digit from following digits.If the widget instead contains the word ‘
regex
’ (or ‘regexp
’), then the matching is performed using regular expressions, respecting the setting of the optionRE_MATCH_PCRE
(see the description of the functionregexp-replace
below). The special replacement facilities described above for pattern matching are available.By default the previous source or replacement string will not be offered for editing. However, this feature can be activated by setting the style
edit-previous
in the context:zle:``widget
(for example,:zle:replace-string
) totrue
. In addition, a positive numeric argument forces the previous values to be offered, a negative or zero argument forces them not to be.The function
replace-string-again
can be used to repeat the previous replacement; no prompting is done. As withreplace-string
, if the name of the widget contains the word ‘pattern
’ or ‘regex
’, 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.In addition,
replace-string
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.For example, starting from the line:
print This line contains fan and fond
and invoking
replace-pattern
with the source string ‘f(?)n
’ and the replacement string ‘c\1r
’ produces the not very useful line:print This line contains car and cord
The range of the replacement string can be limited by using the
narrow-to-region-invisible
widget. One limitation of the current version is thatundo
will cycle through changes to the replacement and source strings before undoing the replacement itself. -
send-invisible
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 (‘*
’) is shown instead. The value is saved in the parameter$INVISIBLE
to which a reference is inserted into the editing buffer at the restored cursor position. If the read was aborted by a keyboard break (typically^G
) or another escape from editing such aspush-line
,$INVISIBLE
is set to empty and the original buffer is restored unchanged.If one argument is supplied to the function it is taken as a prompt, otherwise ‘
Non-echoed text:
’ is used (as in emacs). If a second and third argument are supplied they are used to begin and end the reference to$INVISIBLE
that is inserted into the buffer. The default is to open with${
, thenINVISIBLE
, and close with}
, but many other effects are possible. -
smart-insert-last-word
This function may replace theinsert-last-word
widget, like so:zle -N insert-last-word smart-insert-last-word
With a numeric argument, or when passed command line arguments in a call from another widget, it behaves like
insert-last-word
, except that words in comments are ignored whenINTERACTIVE_COMMENTS
is set.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
match
style. The context used to look up the style is the widget name, so usually the context is:insert-last-word
. However, you can bind this function to different widgets to use different patterns:zle -N insert-last-assignment smart-insert-last-word zstyle :insert-last-assignment match '[[:alpha:]][][[:alnum:]]#=*' bindkey '\e=' insert-last-assignment
If no interesting word is found and the
auto-previous
style is set to a true value, the search continues upward through the history. Whenauto-previous
is unset or false (the default), the widget must be invoked repeatedly in order to search earlier history lines. -
transpose-lines
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.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.
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.
-
url-quote-magic
This widget replaces the built-inself-insert
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.Styles to control quoting behavior:
-
url-metas
This style is looked up in the context ‘:url-quote-magic:``scheme
’ (wherescheme
is that of the current URL, e.g. "ftp
"). 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 ’<
’ and ’>
’ but including braces (as in brace expansion). See alsourl-seps
. -
url-seps
Likeurl-metas
, 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 ’<
’ and ’>
’ and the first character of$histchars
. -
url-globbers
This style is looked up in the context ‘:url-quote-magic
’. 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 ‘noglob
’ modifier. When the first word on the line matches one of the values and the URL refers to a local file (seeurl-local-schema
), only theurl-seps
characters are quoted; theurl-metas
are left alone, allowing them to affect command-line parsing, completion, etc. The default values are a literal ‘noglob
’ plus (when thezsh/parameter
module is available) any commands aliased to the helper function ‘urlglobber
’ or its alias ‘globurl
’. -
url-local-schema
This style is always looked up in the context ‘:urlglobber
’, 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 "ftp
" and "file
". -
url-other-schema
Likeurl-local-schema
, but lists all other URI schema upon whichurlglobber
andurl-quote-magic
should act. If the URI on the command line does not have a scheme appearing either in this list or inurl-local-schema
, it is not magically quoted. The default values are "http
", "https
", and "ftp
". When a scheme appears both here and inurl-local-schema
, it is quoted differently depending on whether the command name appears inurl-globbers
.
Loading
url-quote-magic
also defines a helper function ‘urlglobber
’ and aliases ‘globurl
’ to ‘noglob urlglobber
’. 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. -
-
vi-pipe
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.The function serves as an example for reading a vi movement command from within a user-defined widget.
-
which-command
This function is a drop-in replacement for the builtin widgetwhich-command
. 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.The style
whence
is available in the context:zle:$WIDGET
; 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 iswhence -c
. -
zcalc-auto-insert
This function is useful together with thezcalc
function described in Mathematical Functions. It should be bound to a key representing a binary operator such as ‘+
’, ‘-
’, ‘*
’ or ‘/
’. When running in zcalc, if the key occurs at the start of the line or immediately following an open parenthesis, the text"ans "
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 variableZCALC_AUTO_INSERT_PREFIX
.Hence, for example, typing ‘
+12
’ followed by return adds 12 to the previous result.If zcalc is in RPN mode (
-r
option) the effect of this binding is automatically suppressed as operators alone on a line are meaningful.When not in zcalc, the key simply inserts the symbol itself.
26.7.2 Utility Functions
These functions are useful in constructing widgets. They should be
loaded with ‘autoload -U
function
’ and called as indicated from
user-defined widgets.
split-shell-arguments
This function splits the line currently being edited into shell
arguments and whitespace. The result is stored in the array reply
. 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 KSH_ARRAYS
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 reply
in order is guaranteed to produce
the original line.
The parameter REPLY
is set to the index of the word in reply
which
contains the character after the cursor, where the first element has
index 1. The parameter REPLY2
is set to the index of the character
under the cursor in that word, where the first character has index 1.
Hence reply
, REPLY
and REPLY2
should all be made local to the
enclosing function.
See the function modify-current-argument
, described below, for an
example of how to call this function.
modify-current-argument
[ expr-using-``$ARG
| func
]
This function provides a simple method of allowing user-defined widgets to modify the command line argument under the cursor (or immediately to the left of the cursor if the cursor is between arguments).
The argument can be an expression which when evaluated operates on the
shell parameter ARG
, which will have been set to the command line
argument under the cursor. The expression should be suitably quoted to
prevent it being evaluated too early.
Alternatively, if the argument does not contain the string ARG
, it is
assumed to be a shell function, to which the current command line
argument is passed as the only argument. The function should set the
variable REPLY
to the new value for the command line argument. If the
function returns non-zero status, so does the calling function.
For example, a user-defined widget containing the following code converts the characters in the argument under the cursor into all upper case:
modify-current-argument '${(U)ARG}'
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:
modify-current-argument '${(qq)${(Q)ARG}}'
The following performs directory expansion on the command line argument and replaces it by the absolute path:
expand-dir() {
REPLY=${~1}
REPLY=${REPLY:a}
}
modify-current-argument expand-dir
In practice the function expand-dir
would probably not be defined
within the widget where modify-current-argument
is called.
26.7.3 Styles
The behavior of several of the above widgets can be controlled by the
use of the zstyle
mechanism. In particular, widgets that interact with
the completion system pass along their context to any completions that
they invoke.
break-keys
This style is used by the incremental-complete-word
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 incremental-complete-word
,
this style is looked up using the context ‘:incremental
’.
completer
The incremental-complete-word
and insert-and-predict
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:
zstyle ':completion:*' completer \
_complete _correct _approximate
zstyle ':completion:incremental:*' completer \
_complete _correct
zstyle ':completion:predict:*' completer \
_complete
It is a good idea to restrict the completers used in prediction, because
they may be automatically invoked as you type. The _list
and _menu
completers should never be used with prediction. The _approximate
,
_correct
, _expand
, and _match
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.
cursor
The insert-and-predict
widget uses this style, in the context
‘:predict
’, to decide where to place the cursor after completion has
been tried. Values are:
-
complete
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 ‘key
’. -
key
The cursor is left after then
th occurrence of the character just inserted, wheren
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.
Any other value for this style unconditionally leaves the cursor at the position where the completion code left it.
list
When using the incremental-complete-word
widget, this style says if
the matches should be listed on every key press (if they fit on the
screen). Use the context prefix ‘:completion:incremental
’.
The insert-and-predict
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
always
. In this case the context is ‘:predict
’ (not
‘:completion:predict
’).
match
This style is used by smart-insert-last-word
to provide a pattern
(using full EXTENDED_GLOB
syntax) that matches an interesting word.
The context is the name of the widget to which smart-insert-last-word
is bound (see above). The default behavior of smart-insert-last-word
is equivalent to:
zstyle :insert-last-word match '*[[:alpha:]/\\]*'
However, you might want to include words that contain spaces:
zstyle :insert-last-word match '*[[:alpha:][:space:]/\\]*'
Or include numbers as long as the word is at least two characters long:
zstyle :insert-last-word match '*([[:digit:]]?|[[:alpha:]/\\])*'
The above example causes redirections like "2>" to be included.
prompt
The incremental-complete-word
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 PS1
and
other prompt parameters:
-
%c
Replaced by the name of the completer function that generated the matches (without the leading underscore). -
%l
When thelist
style is set, replaced by ‘...
’ if the list of matches is too long to fit on the screen and with an empty string otherwise. If thelist
style is ‘false’ or not set, ‘%l
’ is always removed. -
%n
Replaced by the number of matches generated. -
%s
Replaced by ‘-no match-
’, ‘-no prefix-
’, 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. -
%u
Replaced by the unambiguous part of all matches, if there is any, and if it is different from the word on the line.
Like ‘break-keys
’, this uses the ‘:incremental
’ context.
stop-keys
This style is used by the incremental-complete-word
widget. Its value
is treated similarly to the one for the break-keys
style (and uses the
same context: ‘:incremental
’). However, in this case all keys matching
the pattern given as its value will stop incremental completion and will
then execute their usual function.
toggle
This boolean style is used by predict-on
and its related widgets in
the context ‘:predict
’. 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
predict-off
.
verbose
This boolean style is used by predict-on
and its related widgets in
the context ‘:predict
’. 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 toggle
style. The default does not display these messages.
widget
This style is similar to the command
style: For widget functions that
use zle
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 (not the name of the calling function,
because one function may be bound to multiple widget names).
zstyle :copy-earlier-word widget smart-insert-last-word
Check the documentation for the calling widget or function to determine
whether the widget
style is used.
26.8 Exception Handling
Two functions are provided to enable zsh to provide exception handling in a form that should be familiar from other languages.
throw
exception
The function throw
throws the named exception
. The name is an
arbitrary string and is only used by the throw
and catch
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.
catch
exception-pattern
The function catch
returns status zero if an exception was thrown and
the pattern exception-pattern
matches its name. Otherwise it returns
status 1. exception-pattern
is a standard shell pattern, respecting
the current setting of the EXTENDED_GLOB
option. An alias catch
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 CAUGHT
is set by catch
to the name of the exception
caught. It is possible to rethrow an exception by calling the throw
function again once an exception has been caught.
The functions are designed to be used together with the always
construct described in Complex
Commands. This is important as
only this construct provides the required support for exceptions. A
typical example is as follows.
{
# "try" block
# ... nested code here calls "throw MyExcept"
} always {
# "always" block
if catch MyExcept; then
print "Caught exception MyExcept"
elif catch ''; then
print "Caught a shell error. Propagating..."
throw ''
fi
# Other exceptions are not handled but may be caught further
# up the call stack.
}
If all exceptions should be caught, the following idiom might be preferable.
{
# ... nested code here throws an exception
} always {
if catch *; then
case $CAUGHT in
(MyExcept)
print "Caught my own exception"
;;
(*)
print "Caught some other exception"
;;
esac
fi
}
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.
The system internally uses the shell variable EXCEPTION
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
EXCEPTION
remains set and may be incorrectly recognised as the name of
an exception if a shell error subsequently occurs. Adding unset EXCEPTION
at the start of the outermost layer of any code that uses
exception handling will eliminate this problem.
26.9 MIME Functions
Three functions are available to provide handling of files recognised by
extension, for example to dispatch a file text.ps
when executed as a
command to an appropriate viewer.
zsh-mime-setup
[ -fv
] [ -l
[ suffix
... ] ]
zsh-mime-handler
[ -l
] command argument
...
These two functions use the files ~/.mime.types
and /etc/mime.types
,
which associate types and extensions, as well as ~/.mailcap
and
/etc/mailcap
files, which associate types and the programs that handle
them. These are provided on many systems with the Multimedia Internet
Mail Extensions.
To enable the system, the function zsh-mime-setup
should be autoloaded
and run. This allows files with extensions to be treated The function
zsh-mime-handler
should not need to be called by the user.
The system works by setting up suffix aliases with ‘alias -s
’. Suffix
aliases already installed by the user will not be overwritten.
For suffixes defined in lower case, upper case variants will also
automatically be handled (e.g. PDF
is automatically handled if
handling for the suffix pdf
is defined), but not vice versa.
Repeated calls to zsh-mime-setup
do not override the existing is
given. Note, however, that this does not override existing suffix
aliases assigned to handlers other than zsh-mime-handler
.
Calling zsh-mime-setup
with the option -l
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.
Calling zsh-mime-setup
with the option -v
causes verbose output to
be shown during the setup operation.
The system respects the mailcap
flags needsterminal
and
copiousoutput
, see man page mailcap(4).
The functions use the following styles, which are defined with the
zstyle
builtin command (The zsh/zutil
Module). They should be
defined before zsh-mime-setup
is run. The contexts used all start with
:mime:
, with additional components in some cases. It is recommended
that a trailing *
(suitably quoted) be appended to style patterns in
case the system is extended in future. Some examples are given below.
For files that have multiple suffixes, e.g. .pdf.gz
, 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
.pdf.gz
produces a match for the handler, that will be used; otherwise
the handler for .gz
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 .pdf.gz
can only be
handled if .gz
is also handled (though not necessarily in the same
way). Alternatively, if no handling for .gz
on its own is needed,
simply adding the command
alias -s gz=zsh-mime-handler
to the initialisation code is sufficient; .gz
will not be handled on
its own, but may be in combination with other suffixes.
current-shell
If this boolean style is true, the mailcap handler for the context in
question is run using the eval
builtin instead of by starting a new
sh
process. This is more efficient, but may not work in the occasional
cases where the mailcap handler uses strict POSIX syntax.
disown
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.
execute-as-is
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 *(*) *(/)
is used; handler, and the option AUTO_CD
may
be used to change to directories that happen to have MIME suffixes.
execute-never
This style is useful in combination with execute-as-is
. It is set to
an array of patterns corresponding to full paths to files that the MIME
handler matches execute-as-is
. This is useful for file from another
operating system. For example, if /mnt/windows
is a Windows mount,
then
zstyle ':mime:*' execute-never '/mnt/windows/*'
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
:P
modifier described in Modifiers; this
means that symbolic links are resolved where possible, so that links
into other file systems behave in the correct fashion.
file-path
Used if the style find-file-in-path
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 path
. The shell option PATH_DIRS
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 ‘/
’. The
full context is :mime:.``suffix``:
, as described for the style
handler
.
find-file-in-path
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
file-path
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
handle-nonexistent
style is set. Files found in the path are tested as
described for the style execute-as-is
. The full context is
:mime:.``suffix``:
, as described for the style handler
.
flags
Defines flags to go with a handler; the context is as for the handler
style, and the format is as for the flags in mailcap
.
handle-nonexistent
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 [[:alpha:]]#:/*
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 :mime:.``suffix``:
, as described for the style
handler
.
handler
Specifies a handler for a suffix; the suffix is given by the context as
:mime:.``suffix``:
, and the format of the handler is exactly that in
mailcap
. Note in particular the ‘.
’ and trailing colon to
distinguish this use of the context. This overrides any handler
specified by the mailcap
files. If the handler requires a terminal,
the flags
style should be set to include the word needsterminal
, or
if the output is to be displayed through a pager (but not if the handler
is itself a pager), it should include copiousoutput
.
mailcap
A list of files in the format of ~/.mailcap
and /etc/mailcap
to be
read during setup, replacing the default list which consists of those
two files. The context is :mime:
. A +
in the list will be replaced
by the default files.
mailcap-priorities
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.
-
files
The order of files (entries in themailcap
style) read. Earlier files are preferred. (Note this does not resolve entries in the same file.) -
priority
The priority flag from the mailcap entry. The priority is an integer from 0 to 9 with the default value being 5. -
flags
The test given by themailcap-prio-flags
option is used to resolve entries. -
place
Later entries are preferred; as the entries are strictly ordered, this test always succeeds.
Note that as this style is handled during initialisation, the context is
always :mime:
, with no discrimination by suffix.
mailcap-prio-flags
This style is used when the keyword flags
is encountered in the list
of tests specified by the mailcap-priorities
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.
mime-types
A list of files in the format of ~/.mime.types
and /etc/mime.types
to be read during setup, replacing the default list which consists of
those two files. The context is :mime:
. A +
in the list will be
replaced by the default files.
never-background
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).
pager
If set, will be used instead of $PAGER
or more
to handle suffixes
where the copiousoutput
flag is set. The context is as for handler
,
i.e. :mime:.``suffix``:
for handling a file with the given suffix
.
Examples:
zstyle ':mime:*' mailcap ~/.mailcap /usr/local/etc/mailcap
zstyle ':mime:.txt:' handler less %s
zstyle ':mime:.txt:' flags needsterminal
When zsh-mime-setup
is subsequently run, it will look for mailcap
entries in the two files given. Files of suffix .txt
will be handled
by running ‘less
file.txt
’. The flag needsterminal
is set to show
that this program must run attached to a terminal.
As there are several steps to dispatching a command, the following
should be checked if attempting to execute a file by extension .``ext
does not have the expected effect.
The command ‘alias -s
ext
’ should show ‘ps=zsh-mime-handler
’. 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 .mime.types
and
mailcap
combination for .ext
files. In that case, appropriate
handling should be added to ~/.mime.types
and mailcap
.
If the extension is handled by zsh-mime-handler
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
zsh-mime-setup -l
will show the handler and, if there are any, the
flags. A %s
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 needsterminal
or
copiousoutput
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.
text/html; /usr/bin/lynx '%s'; needsterminal
Running ‘zsh-mime-handler -l
command line
’ 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 zsh-mime-setup
.
pick-web-browser
This function is separate from the two MIME functions described above and can be assigned directly to a suffix:
autoload -U pick-web-browser
alias -s html=pick-web-browser
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.
Various styles are available to customize the choice of browsers:
-
browser-style
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-
running
Use a GUI browser that is already running when an X Window display is available. The browsers listed in thex-browsers
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. -
x
Start a new GUI browser when an X Window display is available. Search for the availability of one of the browsers listed in thex-browsers
style and start the first one that is found. No check is made for an already running browser. -
tty
Start a terminal-based browser. Search for the availability of one of the browsers listed in thetty-browsers
style and start the first one that is found.
If the style is not set the default
running x tty
is used. -
-
x-browsers
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:mime:
(which may be extended in future, so appending ‘*
’ is recommended). For example,zstyle ':mime:*' x-browsers opera konqueror firefox
specifies that
pick-web-browser
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 isfirefox mozilla netscape opera konqueror
. -
tty-browsers
An array similar tox-browsers
, except that it gives browsers to use when no X Window display is available. The default iselinks links lynx
. -
command
If it is set this style is used to pick the command used to open a page for a browser. The context is:mime:browser:new:$browser:
to start a new browser or:mime:browser:running:$browser:
to open a URL in a browser already running on the current X display, where$browser
is the value matched in thex-browsers
ortty-browsers
style. The escape sequence%b
in the style’s value will be replaced by the browser, while%u
will be replaced by the URL. If the style is not set, the default for all new instances is equivalent to%b %u
and the defaults for using running browsers are equivalent to the valueskfmclient openURL %u
for Konqueror,firefox -new-tab %u
for Firefox,opera -newpage %u
for Opera, and%b -remote "openUrl(%u)"
for all others.
26.10 Mathematical Functions
zcalc
[ -erf
] [ expression
... ]
A reasonably powerful calculator based on zsh’s arithmetic evaluation facility. The syntax is similar to that of formulae in most programming languages; see Arithmetic Evaluation for details.
Non-programmers should note that, as in many other programming
languages, expressions involving only integers (whether constants
without a ‘.
’, 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 -f
; see
further notes below.
If the file ~/.zcalcrc
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; emulate -L zsh
and setopt extendedglob
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 $ZDOTDIR
is used instead of $HOME
if it is set.
The mathematical library zsh/mathfunc
will be loaded if it is
available; see The zsh/mathfunc
Module. The mathematical
functions correspond to the raw system libraries, so trigonometric
functions are evaluated using radians, and so on.
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 ‘4>
’ is available as $4
. The last value
calculated is available as ans
. Full command line editing, including
the history of previous calculations, is available; the history is saved
in the file ~/.zcalc_history
. To exit, enter a blank line or type
‘:q
’ on its own (‘q
’ is allowed for historical compatibility).
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 ‘...
’ 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
zcalc
will prompt for more input.
If arguments are given to zcalc
on start up, they are used to prime
the first few positional parameters. A visual indication of this is
given when the calculator starts.
The constants PI
(3.14159...) and E
(2.71828...) are provided.
Parameter assignment is possible, but note that all parameters will be
put into the global namespace unless the :local
special command is
used. The function creates local variables whose names start with _
,
so users should avoid doing so. The variables ans
(the last answer)
and stack
(the stack in RPN mode) may be referred to directly; stack
is an array but elements of it are numeric. Various other special
variables are used locally with their standard meaning, for example
compcontext
, match
, mbegin
, mend
, psvar
.
The output base can be initialised by passing the option ‘-#``base
’,
for example ‘zcalc -#16
’ (the ‘#
’ may have to be quoted, depending
on the globbing options set).
If the option ‘-e
’ is set, the function runs non-interactively: the
arguments are treated as expressions to be evaluated as if entered
interactively line by line.
If the option ‘-f
’ is set, all numbers are treated as floating point,
hence for example the expression ‘3/4
’ evaluates to 0.75 rather than
- Options must appear in separate words.
If the option ‘-r
’ is set, RPN (Reverse Polish Notation) mode is
entered. This has various additional properties:
-
Stack
Evaluated values are maintained in a stack; this is contained in an array namedstack
with the most recent value in${stack[1]}
. -
Operators and functions
If the line entered matches an operator (+
,-
,*
,/
,**
,^
,|
or&
) or a function supplied by thezsh/mathfunc
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${stack[1]}
. -
Expressions
Other expressions are evaluated normally, printed, and added to the stack as numeric values. The syntax within expressions on a single line is normal shell arithmetic (not RPN). -
Stack listing
If an integer follows the option-r
with no space, then on every evaluation that many elements of the stack, where available, are printed instead of just the most recent result. Hence, for example,zcalc -r4
shows$stack[4]
to$stack[1]
each time results are printed. -
Duplication:
=
The pseudo-operator=
causes the most recent element of the stack to be duplicated onto the stack. -
pop
The pseudo-functionpop
causes the most recent element of the stack to be popped. A ‘>
’ on its own has the same effect. -
>``ident
The expression>
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 thezcalc
function. -
<``ident
The expression<
followed (with no space) by a shell identifier causes the value of the variable with that name to be pushed onto the stack.ident
may be an integer, in which case the previous result with that number (as shown before the>
in the standardzcalc
prompt) is put on the stack. -
Exchange:
xy
The pseudo-functionxy
causes the most recent two elements of the stack to be exchanged. ‘<>
’ has the same effect.
The prompt is configurable via the parameter ZCALCPROMPT
, which
undergoes standard prompt expansion. The index of the current entry is
stored locally in the first element of the array psvar
, which can be
referred to in ZCALCPROMPT
as ‘%1v
’. The default prompt is ‘%1v>
’.
The variable ZCALC_ACTIVE
is set within the function and can be tested
by nested functions; it has the value rpn
if RPN mode is active, else
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 compinit
has been run.
The output precision may be specified within zcalc by special commands familiar from many calculators.
-
:norm
The default output format. It corresponds to the printf%g
specification. Typically this shows six decimal digits. -
:sci
digits
Scientific notation, corresponding to the printf%g
output format with the precision given bydigits
. This produces either fixed point or exponential notation depending on the value output. -
:fix
digits
Fixed point notation, corresponding to the printf%f
output format with the precision given bydigits
. -
:eng
digits
Exponential notation, corresponding to the printf%E
output format with the precision given bydigits
. -
:raw
Raw output: this is the default form of the output from a math evaluation. This may show more precision than the number actually possesses.
Other special commands:
-
:!``line...
Executeline...
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:!
. -
:local
arg
...
Declare variables local to the function. Other variables may be used, too, but they will be taken from or put into the global scope. -
:function
name
[body
]
Define a mathematical function or (with nobody
) delete it.:function
may be abbreviated to:func
or simply:f
. Thename
may contain the same characters as a shell function name. The function is defined usingzmathfuncdef
, see below.Note that
zcalc
takes care of all quoting. Hence for example::f cube $1 * $1 * $1
defines a function to cube the sole argument. Functions so defined, or indeed any functions defined directly or indirectly using
functions -M
, 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 examplecube
function. If there are optional arguments only the mandatory arguments are supplied by this means. -
[#``base``]
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 tobase
. Use, for example, ‘[#16]
’ to display hexadecimal output preceded by an indication of the base, or ‘[##16]
’ just to display the raw number in the given base. Bases themselves are always specified in decimal. ‘[#]
’ restores the normal output format. Note that setting an output base suppresses floating point output; use ‘[#]
’ to return to normal operation. -
$``var
Print out the value of var literally; does not affect the calculation. To use the value of var, omit the leading ‘$
’.
See the comments in the function for a few extra tips.
min(``arg``, ...)
max(``arg``, ...)
sum(``arg``, ...)
zmathfunc
The function zmathfunc
defines the three mathematical functions min
,
max
, and sum
. The functions min
and max
take one or more
arguments. The function sum
takes zero or more arguments. Arguments
can be of different types (ints and floats).
Not to be confused with the zsh/mathfunc
module, described in The
zsh/mathfunc Module.
zmathfuncdef
[ mathfunc
[ body
] ]
A convenient front end to functions -M
.
With two arguments, define a mathematical function named mathfunc
which can be used in any form of arithmetic evaluation. body
is a
mathematical expression to implement the function. It may contain
references to position parameters $1
, $2
, ... to refer to mandatory
parameters and ${1:-``defvalue``}
... to refer to optional parameters.
Note that the forms must be strictly adhered to for the function to
calculate the correct number of arguments. The implementation is held in
a shell function named zsh_math_func_``mathfunc
; usually the user will
not need to refer to the shell function directly. Any existing function
of the same name is silently replaced.
With one argument, remove the mathematical function mathfunc
as well
as the shell function implementation.
With no arguments, list all mathfunc
functions in a form The functions
have not necessarily been defined by zmathfuncdef
.
26.11 User Configuration Functions
The zsh/newuser
module comes with a function to aid in configuring
shell options for new users. If the module is installed, this function
can also be run by hand. It is available even if the module’s default
behaviour, namely running the function for a new user logging in without
startup files, is inhibited.
-
zsh-newuser-install
[-f
]
The function presents the user with various options for customizing their initialization scripts. Currently only~/.zshrc
is handled.$ZDOTDIR/.zshrc
is used instead if the parameterZDOTDIR
is set; this provides a way for the user to configure a file without altering an existing.zshrc
.By default the function exits immediately if it finds any of the files
.zshenv
,.zprofile
,.zshrc
, or.zlogin
in the appropriate directory. The option-f
is required in order to force the function to continue. Note this may happen even if.zshrc
itself does not exist.As currently configured, the function will exit immediately if the user has root privileges; this behaviour cannot be overridden.
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.
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 ‘
# Lines configured by zsh-newuser-install
’ and ‘# End of lines configured by zsh-newuser-install
’. In addition, the old version of.zshrc
is saved to a file with the suffix.zni
appended.If the function edits an existing
.zshrc
, 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.zshrc
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.
26.12 Other Functions
There are a large number of helpful functions in the Functions/Misc
directory of the zsh distribution. Most are very simple and do not
require documentation here, but a few are worthy of special mention.
26.12.1 Descriptions
colors
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 (Prompt Themes). You
seldom should need to run colors
more than once.
The eight base colors are: black
, red
, green
, yellow
, blue
,
magenta
, cyan
, and white
. Each of these has codes for foreground
and background. In addition there are seven intensity attributes:
bold
, faint
, standout
, underline
, blink
, reverse
, and
conceal
. Finally, there are seven codes used to negate attributes:
none
(reset all attributes to the defaults), normal
(neither bold
nor faint), no-standout
, no-underline
, no-blink
, no-reverse
, and
no-conceal
.
Some terminals do not support all combinations of colors and intensities.
The associative arrays are:
-
color
colour
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 ‘fg-
’, such as ‘fg-red
’. Names prefixed with ‘bg-
’, such as ‘bg-blue
’, refer to the background codes. The reverse mapping from code to color yields base name for foreground codes and thebg-
form for backgrounds.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.
-
fg
fg_bold
fg_no_bold
Map the eight basic color names to ANSI terminal escape sequences that set the corresponding foreground text properties. Thefg
sequences change the color without changing the eight intensity attributes. -
bg
bg_bold
bg_no_bold
Map the eight basic color names to ANSI terminal escape sequences that set the corresponding background properties. Thebg
sequences change the color without changing the eight intensity attributes.
In addition, the scalar parameters reset_color
and bold_color
are
set to the ANSI terminal escapes that turn off all attributes and turn
on bold intensity, respectively.
fned
[ -x
num
] name
Same as zed -f
. This function does not appear in the zsh distribution,
but can be created by linking zed
to the name fned
in some directory
in your fpath
.
is-at-least
needed
[ present
]
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 present
string is
not provided, $ZSH_VERSION
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.
This is useful in startup files to set options and other state that are not available in all versions of zsh.
is-at-least 3.1.6-15 && setopt NO_GLOBAL_RCS
is-at-least 3.1.0 && setopt HIST_REDUCE_BLANKS
is-at-least 2.6-17 || print "You can't use is-at-least here."
nslookup
[ arg
... ]
This wrapper function for the nslookup
command requires the zsh/zpty
module (see The zsh/zpty
Module). It behaves exactly
like the standard nslookup
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
‘:completion:nslookup
’.
See also the pager
, prompt
and rprompt
styles below.
regexp-replace
var
regexp
replace
Use regular expressions to perform a global search and replace operation
on a variable. POSIX extended regular expressions are used, unless the
option RE_MATCH_PCRE
has been set, in which case Perl-compatible
regular expressions are used (this requires the shell to be linked
against the pcre
library).
var
is the name of the variable containing the string to be matched.
The variable will be modified directly by the function. The variables
MATCH
, MBEGIN
, MEND
, match
, mbegin
, mend
should be avoided
as these are used by the regular expression code.
regexp
is the regular expression to match against the string.
replace
is the replacement text. This can contain parameter, command
and arithmetic expressions which will be replaced: in particular, a
reference to $MATCH
will be replaced by the text matched by the
pattern.
The return status is 0 if at least one match was performed, else 1.
run-help
cmd
This function is designed to be invoked by the run-help
ZLE widget, in
place of the default alias. See ‘Accessing On-Line Help’
(Utilities) for setup instructions.
In the discussion which follows, if cmd
is a file system path, it is
first reduced to its rightmost component (the file name).
Help is first sought by looking for a file named cmd
in the directory
named by the HELPDIR
parameter. If no file is found, an assistant
function, alias, or command named run-help-cmd
is sought. If found,
the assistant is executed with the rest of the current command line
(everything after the command name cmd
) as its arguments. When neither
file nor assistant is found, the external command ‘man
cmd
’ is run.
An example assistant for the "ssh" command:
run-help-ssh() {
emulate -LR zsh
local -a args
# Delete the "-l username" option
zparseopts -D -E -a args l:
# Delete other options, leaving: host command
args=(${@:#-*})
if [[ ${#args} -lt 2 ]]; then
man ssh
else
run-help $args[2]
fi
}
Several of these assistants are provided in the Functions/Misc
your
search path, in order to be found and used by run-help
.
run-help-git
run-help-ip
run-help-openssl
run-help-p4
run-help-sudo
run-help-svk
run-help-svn
Assistant functions for the git
, ip
, openssl
, p4
, sudo
, svk
,
and svn
, commands.
tetris
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.
This function must be used as a ZLE widget:
autoload -U tetris
zle -N tetris
bindkey keys tetris
To start a game, execute the widget by typing the keys
. 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 ‘q
’) or
when you lose.
If you quit in the middle of a game, the next invocation of the tetris
widget will continue where you left off. If you lost, it will start a
new game.
tetriscurses
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.
This version does not save the game state between invocations, and is not invoked as a widget, but rather as:
autoload -U tetriscurses
tetriscurses
zargs
[ option
... -``-
] [ input
... ] [ -``-
command
[ arg
... ] ]
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.
The option
list represents options of the zargs
command itself,
which are the same as those of xargs
. The input
list is the
collection of strings (often file names) that become the arguments of
the command
, analogous to the standard input of xargs
. Finally, the
arg
list consists of those arguments (usually options) that are passed
to the command
each time it runs. The arg
list precedes the elements
from the input
list in each run. If no command
is provided, then no
arg
list may be provided, and in that event the default command is
‘print
’ with arguments ‘-r -``-
’.
For example, to get a long ls
listing of all non-hidden plain files in
the current directory or its subdirectories:
autoload -U zargs
zargs -- **/*(.) -- ls -ld --
The first and third occurrences of ‘-``-
’ are used to mark the end of
options for zargs
and ls
respectively to guard against filenames
starting with ‘-
’, while the second is used to separate the list of
files from the command to run (‘ls -ld –
’).
The first ‘-``-
’ would also be needed if there was a chance the list
might be empty as in:
zargs -r -- ./*.back(#qN) -- rm -f
In the event that the string ‘-``-
’ is or may be an input
, the -e
option may be used to change the end-of-inputs marker. Note that this
does not change the end-of-options marker. For example, to use ‘..
’
as the marker:
zargs -e.. -- **/*(.) .. ls -ld --
This is a good choice in that example because no plain file can be named
‘..
’, but the best end-marker depends on the circumstances.
The options -i
, -I
, -l
, -L
, and -n
differ slightly from their
usage in xargs
. There are no input lines for zargs
to count, so -l
and -L
count through the input
list, and -n
counts the number of
arguments passed to each execution of command
, including any arg
list. Also, any time -i
or -I
is used, each input
is processed
separately as if by ‘-L
1
’.
For details of the other zargs
options, see man page xargs(1) (but
note the difference in function between zargs
and xargs
) or run
zargs
with the -``-help
option.
zed
[ -f
[ -x
num
] ] name
zed -b
This function uses the ZLE editor to edit a file or function.
Only one name
argument is allowed. If the -f
option is given, the
name is taken to be that of a function; if the function is marked for
autoloading, zed
searches for it in the fpath
and loads it. Note
that functions edited this way are installed into the current shell, but
not written back to the autoload file. In this case the -x
option
specifies that leading tabs indenting the function according to syntax
should be converted into the given number of spaces; ‘-x 2
’ is
consistent with the layout of functions distributed with the shell.
Without -f
, name
is the path name of the file to edit, which need
not exist; it is created on write, if necessary.
While editing, the function sets the main keymap to zed
and the vi
command keymap to zed-vicmd
. These will be copied from the existing
main
and vicmd
keymaps if they do not exist the first time zed
is
run. They can be used to provide special key bindings used only in zed.
If it creates the keymap, zed
rebinds the return key to insert a line
break and ‘^X^W
’ to accept the edit in the zed
keymap, and binds
‘ZZ
’ to accept the edit in the zed-vicmd
keymap.
The bindings alone can be installed by running ‘zed -b
’. This is this
will overwrite the existing zed
and zed-vicmd
keymaps.
Completion is available, and styles may be set with the context prefix
‘:completion:zed
’.
A zle widget zed-set-file-name
is available. This can be called by
name from within zed using ‘\ex zed-set-file-name
’ (note, however,
that because of zed’s rebindings you will have to type ^j
at the end
instead of the return key), or can be bound to a key in either of the
zed
or zed-vicmd
keymaps after ‘zed -b
’ 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 ‘zed -f
’.
While zed-set-file-name
is running, zed uses the keymap
zed-normal-keymap
, 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.
zcp
[ -finqQvwW
] srcpat
dest
zln
[ -finqQsvwW
] srcpat
dest
Same as zmv -C
and zmv -L
, respectively. These functions do not
appear in the zsh distribution, but can be created by linking zmv
to
the names zcp
and zln
in some directory in your fpath
.
zkbd
See ‘Keyboard Definition’ (Utilities).
zmv
[ -finqQsvwW
] [ -C
| -L
| -M
| -{p
|P
} program
]
[ -o
optstring
]
``srcpat
dest
Move (usually, rename) files matching the pattern srcpat
to
corresponding files having names of the form given by dest
, where
srcpat
contains parentheses surrounding patterns which will be
replaced in turn by $1
, $2
, ... in dest
. For example,
zmv '(*).lis' '$1.txt'
renames ‘foo.lis
’ to ‘foo.txt
’, ‘my.old.stuff.lis
’ to
‘my.old.stuff.txt
’, and so on.
The pattern is always treated as an EXTENDED_GLOB
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
-f
was not given) causes the entire function to abort without doing
anything.
In addition to pattern replacement, the variable $f
can be referrred
to in the second (replacement) argument. This makes it possible to use
variable substitution to alter the argument; see examples below.
Options:
-
-f
Force overwriting of destination files. Not currently passed down to themv
/cp
/ln
command due to vagaries of implementations (but you can use-o-f
to do that). -
-i
Interactive: show each line to be executed and ask the user whether to execute it. ‘Y
’ or ‘y
’ will execute it, anything else will skip it. Note that you just need to type one character. -
-n
No execution: print what would happen, but don’t do it. -
-q
Turn bare glob qualifiers off: now assumed by default, so this has no effect. -
-Q
Force bare glob qualifiers on. Don’t turn this on unless you are actually using glob qualifiers in a pattern. -
-s
Symbolic, passed down toln
; only works with-L
. -
-v
Verbose: print each command as it’s being executed. -
-w
Pick out wildcard parts of the pattern, as described above, and implicitly add parentheses for referring to them. -
-W
Just like-w
, with the addition of turning wildcards in the replacement pattern into sequential${1}
..${N}
references. -
-C
-L
-M
Forcecp
,ln
ormv
, respectively, regardless of the name of the function. -
-p
program
Callprogram
instead ofcp
,ln
ormv
. Whatever it does, it should at least understand the formprogram -- oldname newname
where
oldname
andnewname
are filenames generated byzmv
.program
will be split into words, so might be e.g. the name of an archive tool plus a copy or rename subcommand. -
-P
program
As-p
program
, except thatprogram
does not accept a following-``-
to indicate the end of options. In this case filenames must already be in a sane form for the program in question. -
-o
optstring
Theoptstring
is split into words and passed down verbatim to thecp
,ln
ormv
command called to perform the work. It should probably begin with a ‘-
’.
Further examples:
zmv -v '(* *)' '${1// /_}'
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.
zmv -v '* *' '${f// /_}'
This does exactly the same by referring to the file name stored in $f
.
For more complete examples and other implementation details, see the
zmv
source file, usually located in one of the directories named in
your fpath
, or in Functions/Misc/zmv
in the zsh distribution.
zrecompile
See ‘Recompiling Functions’ (Utilities).
zstyle+
context
style
value
[ +
subcontext
style
value
... ]
This makes defining styles a bit simpler by using a single ‘+
’ as a
special token that allows you to append a context name to the previously
used context name. Like this:
zstyle+ ':foo:bar' style1 value1 \
+':baz' style2 value2 \
+':frob' style3 value3
This defines style1
with value1
for the context :foo:bar
as usual,
but it also defines style2
with value2
for the context
:foo:bar:baz
and style3
with value3
for :foo:bar:frob
. Any
subcontext
may be the empty string to re-use the first context
unchanged.
26.12.2 Styles
insert-tab
The zed
function sets this style in context ‘:completion:zed:*
’ to
turn off completion when TAB
is typed at the beginning of a line. You
may override this by setting your own value for this context and style.
pager
The nslookup
function looks up this style in the context ‘:nslookup
’
to determine the program used to display output that does not fit on a
single screen.
prompt
rprompt
The nslookup
function looks up this style in the context ‘:nslookup
’
to set the prompt and the right-side prompt, respectively. The usual
expansions for the PS1
and RPS1
parameters may be used (see Prompt
Expansion).
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.