<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
**Table of Contents**  *generated with [DocToc](https://github.com/thlorenz/doctoc)*

- [22 Zsh Modules](#22-zsh-modules)
  - [22.1 Description](#221-description)
  - [22.2 The zsh/attr Module](#222-the-zshattr-module)
  - [22.3 The zsh/cap Module](#223-the-zshcap-module)
  - [22.4 The zsh/clone Module](#224-the-zshclone-module)
  - [22.5 The zsh/compctl Module](#225-the-zshcompctl-module)
  - [22.6 The zsh/complete Module](#226-the-zshcomplete-module)
  - [22.7 The zsh/complist Module](#227-the-zshcomplist-module)
    - [22.7.1 Colored completion listings](#2271-colored-completion-listings)
    - [22.7.2 Scrolling in completion listings](#2272-scrolling-in-completion-listings)
    - [22.7.3 Menu selection](#2273-menu-selection)
  - [22.8 The zsh/computil Module](#228-the-zshcomputil-module)
  - [22.9 The zsh/curses Module](#229-the-zshcurses-module)
    - [22.9.1 Builtin](#2291-builtin)
    - [22.9.2 Parameters](#2292-parameters)
  - [22.10 The zsh/datetime Module](#2210-the-zshdatetime-module)
  - [22.11 The zsh/db/gdbm Module](#2211-the-zshdbgdbm-module)
  - [22.12 The zsh/deltochar Module](#2212-the-zshdeltochar-module)
  - [22.13 The zsh/example Module](#2213-the-zshexample-module)
  - [22.14 The zsh/files Module](#2214-the-zshfiles-module)
  - [22.15 The zsh/langinfo Module](#2215-the-zshlanginfo-module)
  - [22.16 The zsh/mapfile Module](#2216-the-zshmapfile-module)
    - [22.16.1 Limitations](#22161-limitations)
  - [22.17 The zsh/mathfunc Module](#2217-the-zshmathfunc-module)
  - [22.18 The zsh/nearcolor Module](#2218-the-zshnearcolor-module)
  - [22.19 The zsh/newuser Module](#2219-the-zshnewuser-module)
  - [22.20 The zsh/parameter Module](#2220-the-zshparameter-module)
  - [22.21 The zsh/pcre Module](#2221-the-zshpcre-module)
  - [22.22 The zsh/param/private Module](#2222-the-zshparamprivate-module)
  - [22.23 The zsh/regex Module](#2223-the-zshregex-module)
  - [22.24 The zsh/sched Module](#2224-the-zshsched-module)
  - [22.25 The zsh/net/socket Module](#2225-the-zshnetsocket-module)
    - [22.25.1 Outbound Connections](#22251-outbound-connections)
    - [22.25.2 Inbound Connections](#22252-inbound-connections)
  - [22.26 The zsh/stat Module](#2226-the-zshstat-module)
  - [22.27 The zsh/system Module](#2227-the-zshsystem-module)
    - [22.27.1 Builtins](#22271-builtins)
    - [22.27.2 Math Functions](#22272-math-functions)
    - [22.27.3 Parameters](#22273-parameters)
  - [22.28 The zsh/net/tcp Module](#2228-the-zshnettcp-module)
    - [22.28.1 Outbound Connections](#22281-outbound-connections)
    - [22.28.2 Inbound Connections](#22282-inbound-connections)
    - [22.28.3 Closing Connections](#22283-closing-connections)
    - [22.28.4 Example](#22284-example)
  - [22.29 The zsh/termcap Module](#2229-the-zshtermcap-module)
  - [22.30 The zsh/terminfo Module](#2230-the-zshterminfo-module)
  - [22.31 The zsh/watch Module](#2231-the-zshwatch-module)
  - [22.32 The zsh/zftp Module](#2232-the-zshzftp-module)
    - [22.32.1 Subcommands](#22321-subcommands)
    - [22.32.2 Parameters](#22322-parameters)
    - [22.32.3 Functions](#22323-functions)
    - [22.32.4 Problems](#22324-problems)
  - [22.33 The zsh/zle Module](#2233-the-zshzle-module)
  - [22.34 The zsh/zleparameter Module](#2234-the-zshzleparameter-module)
  - [22.35 The zsh/zprof Module](#2235-the-zshzprof-module)
  - [22.36 The zsh/zpty Module](#2236-the-zshzpty-module)
  - [22.37 The zsh/zselect Module](#2237-the-zshzselect-module)
  - [22.38 The zsh/zutil Module](#2238-the-zshzutil-module)

<!-- END doctoc generated TOC please keep comment here to allow auto update -->

<span id="Zsh-Modules"></span> <span id="Zsh-Modules-1"></span>

# 22 Zsh Modules

<span id="index-modules"></span>

------------------------------------------------------------------------

<span id="Description-4"></span>

## 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](Shell-Builtin-Commands.html#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  
The compctl 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 the stat 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/watch  
Reporting of login and logout events.

zsh/zftp  
A builtin FTP client.

zsh/zle  
The Zsh Line Editor, including the bindkey and vared 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.

------------------------------------------------------------------------

<span id="The-zsh_002fattr-Module"></span> <span
id="The-zsh_002fattr-Module-1"></span>

## 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:

<span id="index-zgetattr"></span> <span
id="index-extended-attributes_002c-xattr_002c-getting-from-files"></span>

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.

<span id="index-zsetattr"></span> <span
id="index-extended-attributes_002c-xattr_002c-setting-on-files"></span>

zsetattr \[ -h \] `filename` `attribute` `value`

Set the extended attribute `attribute` on the specified `filename` to
`value`.

<span id="index-zdelattr"></span> <span
id="index-extended-attributes_002c-xattr_002c-removing_002c-deleting"></span>

zdelattr \[ -h \] `filename` `attribute`

Remove the extended attribute `attribute` from the specified `filename`.

<span id="index-zlistattr"></span> <span
id="index-extended-attributes_002c-xattr_002c-listing"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fcap-Module"></span> <span
id="The-zsh_002fcap-Module-1"></span>

## 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:

<span id="index-cap"></span> <span
id="index-capabilities_002c-setting"></span>

cap \[ `capabilities` \]

Change the shell’s process capability sets to the specified
`capabilities`, otherwise display the shell’s current capabilities.

<span id="index-getcap"></span> <span
id="index-capabilities_002c-getting-from-files"></span>

getcap `filename` ...

This is a built-in implementation of the POSIX standard utility. It
displays the capability sets on each specified `filename`.

<span id="index-setcap"></span> <span
id="index-capabilities_002c-setting-on-files"></span>

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`.

------------------------------------------------------------------------

<span id="The-zsh_002fclone-Module"></span> <span
id="The-zsh_002fclone-Module-1"></span>

## 22.4 The zsh/clone Module

The zsh/clone module makes available one builtin command:

<span id="index-clone"></span> <span
id="index-shell_002c-cloning"></span> <span
id="index-cloning-the-shell"></span> <span id="index-terminal"></span>

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

<div class="example">

```zsh
xterm -e sh -c 'trap : INT QUIT TSTP; tty;
        while :; do sleep 100000000; done'
```

</div>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fcompctl-Module"></span> <span
id="The-zsh_002fcompctl-Module-1"></span>

## 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](Completion-Using-compctl.html#Completion-Using-compctl).
The other builtin command, compcall can be used in user-defined
completion widgets, see [Completion
Widgets](Completion-Widgets.html#Completion-Widgets).

------------------------------------------------------------------------

<span id="The-zsh_002fcomplete-Module"></span> <span
id="The-zsh_002fcomplete-Module-1"></span>

## 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](Completion-Widgets.html#Completion-Widgets).

------------------------------------------------------------------------

<span id="The-zsh_002fcomplist-Module"></span> <span
id="The-zsh_002fcomplist-Module-1"></span>

## 22.7 The zsh/complist Module

<span id="index-completion_002c-listing-1"></span> <span
id="index-completion_002c-coloured-listings"></span> <span
id="index-completion_002c-scroll-listings"></span>

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.

------------------------------------------------------------------------

<span id="Colored-completion-listings"></span>

### 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.

<span id="index-ZLS_005fCOLORS"></span> <span
id="index-ZLS_005fCOLOURS"></span>

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 value target, 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 for ln)

mi `none`  
for a non-existent file (default is the value defined for fi); 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
the LIST_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 xterms. 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](User-Contributions.html#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](Completion-System.html#Completion-System-Configuration)).

------------------------------------------------------------------------

<span id="Scrolling-in-completion-listings"></span>

### 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.

------------------------------------------------------------------------

<span id="Menu-selection"></span>

### 22.7.3 Menu selection

<span id="index-completion_002c-selecting-by-cursor"></span> <span
id="index-MENUSELECT"></span> <span id="index-menu_002dselect"></span>

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](Options.html#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](Zsh-Line-Editor.html#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 use undo 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 to self-insert and self-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 and undo and
backward-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](#The-zsh_002fzle-Module)). For example, to make the
return key leave menu selection without accepting the match currently
selected one could call

<div class="example">

```zsh
bindkey -M menuselect '^M' send-break
```

</div>

after loading the zsh/complist module.

------------------------------------------------------------------------

<span id="The-zsh_002fcomputil-Module"></span> <span
id="The-zsh_002fcomputil-Module-1"></span>

## 22.8 The zsh/computil Module

<span id="index-completion_002c-utility"></span>

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](Completion-System.html#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:

<span id="index-comparguments"></span>

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.

<span id="index-compdescribe"></span>

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.

<span id="index-compfiles"></span>

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.

<span id="index-compgroups"></span>

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).

<span id="index-compquote"></span>

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.

<span id="index-comptags"></span> <span id="index-comptry"></span>

comptags

comptry

These implement the internals of the tags mechanism.

<span id="index-compvalues"></span>

compvalues

Like comparguments, but for the \_values function.

------------------------------------------------------------------------

<span id="The-zsh_002fcurses-Module"></span> <span
id="The-zsh_002fcurses-Module-1"></span>

## 22.9 The zsh/curses Module

The zsh/curses module makes available one builtin command and various
parameters.

------------------------------------------------------------------------

<span id="Builtin"></span>

### 22.9.1 Builtin

<span id="index-zcurses"></span> <span
id="index-windows_002c-curses"></span>

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 refreshing 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 of
`targetwin`

\-  
The y and x coordinates of the top left of `targetwin` on the screen

\-  
The size of `targetwin` 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 of PRESSED, RELEASED, CLICKED, DOUBLE_CLICKED or
TRIPLE_CLICKED followed immediately (in the same element) by the number
of the button.

\-  
If the shift key was pressed, the string SHIFT.

\-  
If the control key was pressed, the string CTRL.

\-  
If the alt key was pressed, the string ALT.

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.

------------------------------------------------------------------------

<span id="Parameters-2"></span>

### 22.9.2 Parameters

<span id="index-ZCURSES_005fCOLORS"></span>

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.

<span id="index-ZCURSES_005fCOLOR_005fPAIRS"></span>

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.

<span id="index-zcurses_005fattrs"></span>

zcurses_attrs

Readonly array. The attributes supported by zsh/curses; available as
soon as the module is loaded.

<span id="index-zcurses_005fcolors"></span>

zcurses_colors

Readonly array. The colors supported by zsh/curses; available as soon as
the module is loaded.

<span id="index-zcurses_005fkeycodes"></span>

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.

<span id="index-zcurses_005fwindows"></span>

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’.

------------------------------------------------------------------------

<span id="The-zsh_002fdatetime-Module"></span> <span
id="The-zsh_002fdatetime-Module-1"></span>

## 22.10 The zsh/datetime Module

The zsh/datetime module makes available one builtin command:

<span id="index-strftime"></span> <span
id="index-date-string_002c-printing"></span>

strftime \[ -s `scalar` \| -n \] `format` \[ `epochtime` \[
`nanoseconds` \] \]

strftime -r \[ -q \] \[ -s `scalar` \| -n \] `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 strftime(3) for
details. The zsh extensions described in [Prompt
Expansion](Prompt-Expansion.html#Prompt-Expansion) are also available.

-n  
Suppress printing a newline after the formatted string.

-q  
Run quietly; suppress printing of all error messages described below.
Errors for invalid `epochtime` values are always printed.

-r  
With the option -r (reverse), use `format` to parse the input string
`timestring` and output the number of seconds since the epoch at which
the time occurred. The parsing is implemented by the system function
strptime; see 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 the `timestring` is
ignored and the local timezone declared by the TZ environment variable
is used; other parameters are set to zero if not present.

If `timestring` does not match `format` the command returns status 1 and
prints an error message. If `timestring` matches `format` but not all
characters in `timestring` were used, the conversion succeeds but also
prints an error message.

If either of the system functions strptime or mktime 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) to
`scalar` 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:

<span id="index-EPOCHREALTIME"></span>

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.

<span id="index-EPOCHSECONDS"></span>

EPOCHSECONDS

An integer value representing the number of seconds since the epoch.

<span id="index-epochtime"></span>

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:

<div class="example">

```zsh
for secs nsecs in $epochtime; do
  ...
done
```

</div>

------------------------------------------------------------------------

<span id="The-zsh_002fdb_002fgdbm-Module"></span> <span
id="The-zsh_002fdb_002fgdbm-Module-1"></span>

## 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:

<span id="index-ztie"></span> <span
id="index-database-tied-array_002c-creating"></span>

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:

<div class="example">

```zsh
local -A sampledb
ztie -d db/gdbm -f sample.gdbm sampledb
```

</div>

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.

<span id="index-zuntie"></span> <span
id="index-database-tied-array_002c-destroying"></span>

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’.

<span id="index-zgdbmpath"></span> <span
id="index-database-file-path_002c-reading"></span>

zgdbmpath `parametername`

Put path to database file assigned to `parametername` into REPLY scalar.

<span id="index-zgdbm_005ftied"></span> <span
id="index-database-tied-arrays_002c-enumerating"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fdeltochar-Module"></span> <span
id="The-zsh_002fdeltochar-Module-1"></span>

## 22.12 The zsh/deltochar Module

The zsh/deltochar module makes available two ZLE functions:

<span id="index-delete_002dto_002dchar"></span>

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.

<span id="index-zap_002dto_002dchar"></span>

zap-to-char

This behaves like delete-to-char, except that the final occurrence of
the character itself is not deleted.

------------------------------------------------------------------------

<span id="The-zsh_002fexample-Module"></span> <span
id="The-zsh_002fexample-Module-1"></span>

## 22.13 The zsh/example Module

The zsh/example module makes available one builtin command:

<span id="index-example"></span> <span
id="index-modules_002c-example"></span> <span
id="index-modules_002c-writing"></span> <span
id="index-writing-modules"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002ffiles-Module"></span> <span
id="The-zsh_002ffiles-Module-1"></span>

## 22.14 The zsh/files Module

<span id="index-files_002c-manipulating"></span>

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:

<div class="example">

```zsh
zmodload -m -F zsh/files b:zf_\*
```

</div>

The commands loaded by default are:

<span id="index-chgrp"></span>

chgrp \[ -hRs \] `group` `filename` ...

Changes group of files specified. This is equivalent to chown with a
`user-spec` argument of ‘:`group`’.

<span id="index-chmod"></span>

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.

<span id="index-chown"></span>

chown \[ -hRs \] `user-spec` `filename` ...

Changes ownership and group of files specified.

The `user-spec` can be in four forms:

`user`  
change owner to `user`; do not change group

`user`::  
change owner to `user`; do not change group

`user`:  
change owner to `user`; change group to `user`’s primary group

`user`:`group`  
change owner to `user`; change group to `group`

:`group`  
do not change owner; change group to `group`

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.

<span id="index-ln"></span>

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.

<span id="index-mkdir"></span>

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 umask(2)) is used.

<span id="index-mv"></span>

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.

<span id="index-rm"></span>

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 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 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.

<span id="index-rmdir"></span>

rmdir `dir` ...

Removes empty directories specified.

<span id="index-sync"></span>

sync

Calls the system call of the same name (see sync(2)), which flushes
dirty buffers to disk. It might return before the I/O has actually been
completed.

------------------------------------------------------------------------

<span id="The-zsh_002flanginfo-Module"></span> <span
id="The-zsh_002flanginfo-Module-1"></span>

## 22.15 The zsh/langinfo Module

The zsh/langinfo module makes available one parameter:

<span id="index-langinfo"></span>

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

------------------------------------------------------------------------

<span id="The-zsh_002fmapfile-Module"></span> <span
id="The-zsh_002fmapfile-Module-1"></span>

## 22.16 The zsh/mapfile Module

<span id="index-parameter_002c-file-access-via"></span>

The zsh/mapfile module provides one special associative array parameter
of the same name.

<span id="index-mapfile"></span>

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’}}")’.

------------------------------------------------------------------------

<span id="Limitations"></span>

### 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.

------------------------------------------------------------------------

<span id="The-zsh_002fmathfunc-Module"></span> <span
id="The-zsh_002fmathfunc-Module-1"></span>

## 22.17 The zsh/mathfunc Module

<span id="index-functions_002c-mathematical"></span> <span
id="index-mathematical-functions"></span>

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,

<div class="example">

```zsh
(( f = sin(0.3) ))
```

</div>

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 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](User-Contributions.html#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

<div class="example">

```zsh
print $(( rand48(seed) ))
print $(( rand48() ))
print $(( rand48(seed) ))
```

</div>

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().

------------------------------------------------------------------------

<span id="The-zsh_002fnearcolor-Module"></span> <span
id="The-zsh_002fnearcolor-Module-1"></span>

## 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:

<div class="example">

```zsh
[[ $COLORTERM = *(24bit|truecolor)* ]] || zmodload zsh/nearcolor
```

</div>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fnewuser-Module"></span> <span
id="The-zsh_002fnewuser-Module-1"></span>

## 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](User-Contributions.html#User-Configuration-Functions).

------------------------------------------------------------------------

<span id="The-zsh_002fparameter-Module"></span> <span
id="The-zsh_002fparameter-Module-1"></span>

## 22.20 The zsh/parameter Module

<span id="index-parameters_002c-special-1"></span>

The zsh/parameter module gives access to some of the internal hash

<span id="index-options-1"></span>

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.

<span id="index-commands"></span>

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

<span id="index-functions-2"></span>

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.

<span id="index-dis_005ffunctions"></span>

dis_functions

Like functions but for disabled functions.

<span id="index-functions_005fsource"></span>

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.

<span id="index-dis_005ffunctions_005fsource"></span>

dis_functions_source

Like functions_source but for disabled functions.

<span id="index-builtins"></span>

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.

<span id="index-dis_005fbuiltins"></span>

dis_builtins

Like builtins but for disabled builtin commands.

<span id="index-reswords"></span>

reswords

This array contains the enabled reserved words.

<span id="index-dis_005freswords"></span>

dis_reswords

Like reswords but for disabled reserved words.

<span id="index-patchars"></span>

patchars

This array contains the enabled pattern characters.

<span id="index-dis_005fpatchars"></span>

dis_patchars

Like patchars but for disabled pattern characters.

<span id="index-aliases"></span>

aliases

This maps the names of the regular aliases currently enabled to their
expansions.

<span id="index-dis_005faliases"></span>

dis_aliases

Like aliases but for disabled regular aliases.

<span id="index-galiases"></span>

galiases

Like aliases, but for global aliases.

<span id="index-dis_005fgaliases"></span>

dis_galiases

Like galiases but for disabled global aliases.

<span id="index-saliases"></span>

saliases

Like raliases, but for suffix aliases.

<span id="index-dis_005fsaliases"></span>

dis_saliases

Like saliases but for disabled suffix aliases.

<span id="index-parameters-1"></span>

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](Expansion.html#Parameter-Expansion) . Setting or
unsetting keys in this array is not possible.

<span id="index-modules-1"></span>

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.

<span id="index-dirstack"></span>

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.

<span id="index-history-2"></span>

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.

<span id="index-historywords"></span>

historywords

A special array containing the words stored in the history. These also
appear in most to least recent order.

<span id="index-jobdirs"></span>

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.

See the jobs builtin for how job information is provided in a subshell.

<span id="index-jobtexts"></span>

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.

See the jobs builtin for how job information is provided in a subshell.

<span id="index-jobstates"></span>

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.

See the jobs builtin for how job information is provided in a subshell.

<span id="index-nameddirs"></span>

nameddirs

This associative array maps the names of named directories to the
pathnames they stand for.

<span id="index-userdirs"></span>

userdirs

This associative array maps user names to the pathnames of their home
directories.

<span id="index-usergroups"></span>

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.

<span id="index-funcfiletrace"></span>

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.

<span id="index-funcsourcetrace"></span>

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.

<span id="index-funcstack"></span>

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.

<span id="index-functrace"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fpcre-Module"></span> <span
id="The-zsh_002fpcre-Module-1"></span>

## 22.21 The zsh/pcre Module

<span id="index-regular-expressions_002c-perl_002dcompatible"></span>

The zsh/pcre module makes some commands available as builtins:

<span id="index-pcre_005fcompile"></span>

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.

<span id="index-pcre_005fstudy"></span>

pcre_study

Studies the previously-compiled PCRE which may result in faster
matching.

<span id="index-pcre_005fmatch"></span>

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":

<div class="example">

```zsh
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
```

</div>

The zsh/pcre module makes available the following test condition:

<span id="index-pcre_002dmatch"></span>

`expr` -pcre-match `pcre`

Matches a string against a perl-compatible regular expression.

For example,

<div class="example">

```zsh
[[ "$text" -pcre-match ^d+$ ]] &&
print text variable contains only "d's".
```

</div>

<span id="index-REMATCH_005fPCRE-1"></span> <span
id="index-NO_005fCASE_005fMATCH-1"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fparam_002fprivate-Module"></span> <span
id="The-zsh_002fparam_002fprivate-Module-1"></span>

## 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:

<span id="index-private"></span> <span
id="index-private-parameter_002c-creating"></span>

private \[ {+\|-}AHUahlmrtux \] \[ {+\|-}EFLRZi \[ `n` \] \] \[
`name`\[=`value`\] ... \]

The private builtin accepts all the same options and arguments as local
([Shell Builtin
Commands](Shell-Builtin-Commands.html#Shell-Builtin-Commands)) except
for the ‘-T’ option. Tied parameters may not be made private.

The ‘-p’ option is presently a no-op because the state of private
parameters cannot reliably be reloaded. This also applies to printing
private parameters with ‘typeset -p’.

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](Options.html#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:

<div class="example">

```zsh
bad_declaration() {
  zmodload zsh/param/private
  private array=( one two three )
}
```

</div>

This construction works because local is already a keyword, and the
module is loaded before the statement is executed:

<div class="example">

```zsh
good_declaration() {
  zmodload zsh/param/private
  local -P array=( one two three )
}
```

</div>

The following is usable in scripts but may have trouble with autoload:

<div class="example">

```zsh
zmodload zsh/param/private
iffy_declaration() {
  private array=( one two three )
}
```

</div>

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. However, the
    private name may not be created outside the local scope when it was
    not previously declared.
-   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.

------------------------------------------------------------------------

<span id="The-zsh_002fregex-Module"></span> <span
id="The-zsh_002fregex-Module-1"></span>

## 22.23 The zsh/regex Module

<span id="index-regular-expressions"></span> <span
id="index-regex"></span>

The zsh/regex module makes available the following test condition:

<span id="index-regex_002dmatch"></span>

`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,

<div class="example">

```zsh
[[ alphabetical -regex-match ^a([^a]+)a([^a]+)a ]] &&
print -l $MATCH X $match
```

</div>

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.

Note that the zsh/regex module logic relies on the host system. The same
`expr` and `regex` pair could produce different results on different
platforms if a `regex` with non-standard syntax is given.

For example, no syntax for matching a word boundary is defined in the
POSIX extended regular expression standard. GNU libc and BSD libc both
provide such syntaxes as extensions (\\b and \[\[:\<:\]\]/\[\[:>:\]\]
respectively), but neither of these syntaxes is supported by both of
these implementations.

Refer to the regcomp(3) and re_format(7) manual pages on your system for
locally-supported syntax.

------------------------------------------------------------------------

<span id="The-zsh_002fsched-Module"></span> <span
id="The-zsh_002fsched-Module-1"></span>

## 22.24 The zsh/sched Module

The zsh/sched module makes available one builtin command and one
parameter.

<span id="index-sched"></span> <span id="index-timed-execution"></span>
<span id="index-execution_002c-timed"></span>

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](#The-zsh_002fdatetime-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’.

<span id="index-zsh_005fscheduled_005fevents"></span>

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](#The-zsh_002fdatetime-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.

------------------------------------------------------------------------

<span id="The-zsh_002fnet_002fsocket-Module"></span> <span
id="The-zsh_002fnet_002fsocket-Module-1"></span>

## 22.25 The zsh/net/socket Module

The zsh/net/socket module makes available one builtin command:

<span id="index-zsocket"></span> <span id="index-sockets"></span> <span
id="index-sockets_002c-Unix-domain"></span>

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.

------------------------------------------------------------------------

<span id="Outbound-Connections-1"></span>

### 22.25.1 Outbound Connections

<span id="index-sockets_002c-outbound-Unix-domain"></span>

zsocket \[ -v \] \[ -d `fd` \] `filename`  
Open a new Unix domain connection to `filename`. The shell parameter
REPLY 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:

<div class="example">

```zsh
exec {REPLY}>&-
```

</div>

------------------------------------------------------------------------

<span id="Inbound-Connections"></span>

### 22.25.2 Inbound Connections

<span id="index-sockets_002c-inbound-Unix-domain"></span>

zsocket -l \[ -v \] \[ -d `fd` \] `filename`  
zsocket -l will open a socket listening on `filename`. The shell
parameter REPLY will be set to the file descriptor associated with that
listener. The file descriptor remains open in subshells

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.

zsocket -a \[ -tv \] \[ -d `targetfd` \] `listenfd`  
zsocket -a will accept an incoming connection to the socket associated
with `listenfd`. The shell parameter REPLY will be set to the file
descriptor associated with the inbound connection. The file descriptor
remains open in subshells

If -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.

------------------------------------------------------------------------

<span id="The-zsh_002fstat-Module"></span> <span
id="The-zsh_002fstat-Module-1"></span>

## 22.26 The zsh/stat Module

The zsh/stat module makes available one builtin command under two
possible names:

<span id="index-zstat"></span> <span id="index-stat"></span> <span
id="index-files_002c-listing"></span> <span
id="index-files_002c-examining"></span>

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 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 the ls -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 an
`array`, one struct 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 in `array` 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 to `hash`. 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 key name.

-f `fd`  
Use the file on file descriptor `fd` instead of named files; no list of
file names is allowed in this case.

-F `fmt`  
Supplies a strftime (see strftime(3)) string for the formatting of the
time elements. The format string supports all of the zsh extensions
described in [Prompt Expansion](Prompt-Expansion.html#Prompt-Expansion).
In particular, -F %s.%N can be used to show timestamps with nanosecond
precision if supported by the system. 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 an lstat (see lstat(2)) rather than a stat system call. In this
case, if the file is a link, information about the link itself rather
than the target file is returned. This option is required to make the
link element useful. It’s important to note that this is the exact
opposite from 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  
Print mode, uid, gid and the three time elements as strings instead of
numbers. In each case the format is like that of ls -l.

-t  
Always show the type names for the elements of struct 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 the struct stat elements.

------------------------------------------------------------------------

<span id="The-zsh_002fsystem-Module"></span> <span
id="The-zsh_002fsystem-Module-1"></span>

## 22.27 The zsh/system Module

The zsh/system module makes available various builtin commands and
parameters.

------------------------------------------------------------------------

<span id="Builtins"></span>

### 22.27.1 Builtins

<span id="index-syserror"></span>

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).

<span id="index-sysopen"></span>

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 if `file` is a symbolic link

nonblock  
the file is opened in nonblocking mode

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:

<div class="example">

```zsh
exec {fd}<&-
exec {fd}>&-
```

</div>

<span id="index-sysread"></span>

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 parameter ERRNO gives the error.

3  
Data were successfully read, but there was an error writing them to
`outfd`. The parameter ERRNO gives the error.

4  
The attempt to read timed out. Note this does not set ERRNO 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 to `outfd` 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 \[ -t `timeout` \] \[ -i `interval` \] \[ -f `var` \]
\[-er\] `file`

zsystem flock -u `fd_expr`

The builtin zsystem’s subcommand flock performs advisory file locking
(via the 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;
fractional seconds are allowed. During this period, the shell will
attempt to lock the file every `interval` seconds if the -i `interval`
option is given, otherwise once a second. (This `interval` is shortened
before the last attempt if needed, so that the shell waits only until
the `timeout` and not longer.) If the attempt times out, status 2 is
returned.

(Note: `timeout` is limited to 2^30-1 seconds (about 34 years), and
`interval` to 0.999 \* LONG_MAX microseconds (only about 35 minutes on
32-bit systems).)

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).

------------------------------------------------------------------------

<span id="Math-Functions"></span>

### 22.27.2 Math Functions

systell(`fd`)  
The systell math function returns the current file position for the file
descriptor passed as an argument.

------------------------------------------------------------------------

<span id="Parameters-1"></span>

### 22.27.3 Parameters

<span id="index-errnos"></span>

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.

<span id="index-sysparams"></span>

sysparams

A readonly associative array. The keys are:

pid  
<span id="index-pid_002c-sysparams"></span>

Returns the process ID of the current process, even in subshells.
Compare $$, which returns the process ID of the main shell process.

ppid  
<span id="index-ppid_002c-sysparams"></span>

Returns the current process ID of the parent of the current process,
even in subshells. Compare $PPID, which returns the process ID of the
initial parent of the main shell process.

procsubstpid  
Returns the process ID of the last process started for process
substitution, i.e. the \<(`...`) and >(`...`) expansions.

------------------------------------------------------------------------

<span id="The-zsh_002fnet_002ftcp-Module"></span> <span
id="The-zsh_002fnet_002ftcp-Module-1"></span>

## 22.28 The zsh/net/tcp Module

The zsh/net/tcp module makes available one builtin command:

<span id="index-ztcp"></span> <span id="index-TCP"></span> <span
id="index-sockets_002c-TCP"></span>

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 the zftp 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.

------------------------------------------------------------------------

<span id="Outbound-Connections"></span>

### 22.28.1 Outbound Connections

<span id="index-sockets_002c-outbound-TCP"></span>

ztcp \[ -v \] \[ -d `fd` \] `host` \[ `port` \]  
Open a new TCP connection to `host`. If the `port` is omitted, it will
default to port 23. The connection will REPLY 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.

------------------------------------------------------------------------

<span id="Inbound-Connections-1"></span>

### 22.28.2 Inbound Connections

<span id="index-sockets_002c-inbound-TCP"></span>

ztcp -l \[ -v \] \[ -d `fd` \] `port`  
ztcp -l will open a socket listening on TCP `port`. 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 with
`listenfd`. 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.

------------------------------------------------------------------------

<span id="Closing-Connections"></span>

### 22.28.3 Closing Connections

<span id="index-sockets_002c-closing-TCP"></span>

ztcp -cf \[ -v \] \[ `fd` \]  
ztcp -c \[ -v \] \[ `fd` \]  
ztcp -c will close the socket associated with `fd`. The socket will be
removed from the

Normally, sockets registered by zftp (see [The zsh/zftp
Module](#The-zsh_002fzftp-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.

------------------------------------------------------------------------

<span id="Example-2"></span>

### 22.28.4 Example

<span id="index-TCP_002c-example"></span>

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,

<div class="example">

```zsh
zmodload zsh/net/tcp
ztcp -l 5123
listenfd=$REPLY
ztcp -a $listenfd
fd=$REPLY
```

</div>

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):

<div class="example">

```zsh
zmodload zsh/net/tcp
ztcp host1 5123
fd=$REPLY
```

</div>

Now on each host, $fd contains a file descriptor for talking to the
other. For example, on host1:

<div class="example">

```zsh
print This is a message >&$fd
```

</div>

and on host2:

<div class="example">

```zsh
read -r line <&$fd; print -r - $line
```

</div>

prints ‘This is a message’.

To tidy up, on host1:

<div class="example">

```zsh
ztcp -c $listenfd
ztcp -c $fd
```

</div>

and on host2

<div class="example">

```zsh
ztcp -c $fd
```

</div>

------------------------------------------------------------------------

<span id="The-zsh_002ftermcap-Module"></span> <span
id="The-zsh_002ftermcap-Module-1"></span>

## 22.29 The zsh/termcap Module

The zsh/termcap module makes available one builtin command:

<span id="index-echotc"></span> <span
id="index-termcap-value_002c-printing"></span>

echotc `cap` \[ `arg` ... \]

Output the termcap value corresponding to the capability `cap`, with
optional arguments.

The zsh/termcap module makes available one parameter:

<span id="index-termcap"></span>

termcap

An associative array that maps termcap capability codes to their values.

------------------------------------------------------------------------

<span id="The-zsh_002fterminfo-Module"></span> <span
id="The-zsh_002fterminfo-Module-1"></span>

## 22.30 The zsh/terminfo Module

The zsh/terminfo module makes available one builtin command:

<span id="index-echoti"></span> <span
id="index-terminfo-value_002c-printing"></span>

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:

<span id="index-terminfo"></span>

terminfo

An associative array that maps terminfo capability names to their
values.

------------------------------------------------------------------------

<span id="The-zsh_002fwatch-Module"></span> <span
id="The-zsh_002fwatch-Module-1"></span>

## 22.31 The zsh/watch Module

The zsh/watch module can be used to report when specific users log in or
out. This is controlled via the following parameters.

<span id="index-LOGCHECK"></span>

LOGCHECK

The interval in seconds between checks for login/logout activity using
the watch parameter.

<span id="index-watch"></span> <span id="index-WATCH"></span>

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:

<div class="example">

```zsh
watch=('^(pws|barts)')
```

</div>

causes reports for activity associated with any user other than pws or
barts.

<span id="index-WATCHFMT"></span>

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.

%F{`color`} (%f)  
Start (stop) using a different foreground color.

%K{`color`} (%k)  
Start (stop) using a different background color.

%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 as `string` using the strftime function, with zsh
extensions as described by [Prompt
Expansion](Prompt-Expansion.html#Prompt-Expansion).

%(`x`:`true-text`:`false-text`)  
Specifies a ternary expression. The character following the `x` 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 the `false-text` is skipped. If
‘false’, the `true-text` is skipped and the `false-text` is formatted
and printed. Either or both of the branches may be empty, but both
separators must be present in any case.

Furthermore, the zsh/watch module makes available one builtin command:

<span id="index-log"></span> <span id="index-watch_002c-use-of"></span>
<span id="index-watching-users"></span> <span
id="index-users_002c-watching"></span>

log

List all users currently logged in who are affected by the current
setting of the watch parameter.

------------------------------------------------------------------------

<span id="The-zsh_002fzftp-Module"></span> <span
id="The-zsh_002fzftp-Module-1"></span>

## 22.32 The zsh/zftp Module

The zsh/zftp module makes available one builtin command:

<span id="index-zftp"></span> <span id="index-FTP"></span> <span
id="index-files_002c-transferring"></span>

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](Zftp-Function-System.html#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.

------------------------------------------------------------------------

<span id="Subcommands"></span>

### 22.32.1 Subcommands

<span id="index-zftp_002c-subcommands"></span>

<span id="index-FTP_002c-starting-a-session"></span>

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,

<div class="example">

```zsh
zftp params ftp.elsewhere.xx juser '?Password for juser: '
```

</div>

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.

------------------------------------------------------------------------

<span id="Parameters-4"></span>

### 22.32.2 Parameters

<span id="index-zftp_002c-parameters"></span>

The following shell parameters are used by zftp. Currently none of them
are special.

<span id="index-ZFTP_005fTMOUT"></span>

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.

<span id="index-ZFTP_005fIP"></span>

ZFTP_IP

Readonly. The IP address of the current connection in dot notation.

<span id="index-ZFTP_005fHOST"></span>

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.

<span id="index-ZFTP_005fPORT"></span>

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.

<span id="index-ZFTP_005fSYSTEM"></span>

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.

<span id="index-ZFTP_005fTYPE"></span>

ZFTP_TYPE

Readonly. The type to be used for data transfers , either ‘A’ or ‘I’.
Use the type subcommand to change this.

<span id="index-ZFTP_005fUSER"></span>

ZFTP_USER

Readonly. The username currently logged in, if any.

<span id="index-ZFTP_005fACCOUNT"></span>

ZFTP_ACCOUNT

Readonly. The account name of the current user, if any. Most servers do
not require an account name.

<span id="index-ZFTP_005fPWD"></span>

ZFTP_PWD

Readonly. The current directory on the server.

<span id="index-ZFTP_005fCODE"></span>

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.

<span id="index-ZFTP_005fREPLY"></span>

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.

<span id="index-ZFTP_005fSESSION"></span>

ZFTP_SESSION

Readonly. The name of the current FTP session; see the description of
the session subcommand.

<span id="index-ZFTP_005fPREFS"></span>

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 letter S occurs
later in the string, zftp will use sendport mode if passive mode is not
available.

S  
Sendport: initiate transfers by the FTP PORT command. If this occurs
before any P in the string, passive mode will never be attempted.

D  
Dumb: use only the bare minimum of FTP commands. This prevents the
variables ZFTP_SYSTEM and ZFTP_PWD from being set, and will mean all
connections default to ASCII type. It may prevent ZFTP_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.

<span id="index-ZFTP_005fVERBOSE"></span>

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.

------------------------------------------------------------------------

<span id="Functions-1"></span>

### 22.32.3 Functions

<span id="index-zftp_002c-functions"></span>

<span id="index-zftp_005fchpwd_002c-specification"></span>

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.

<span id="index-zftp_005fprogress_002c-specification"></span>

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:

<span id="index-ZFTP_005fFILE"></span>

ZFTP_FILE

The name of the remote file being transferred from or to.

<span id="index-ZFTP_005fTRANSFER"></span>

ZFTP_TRANSFER

A G for a get operation and a P for a put operation.

<span id="index-ZFTP_005fSIZE"></span>

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.

<span id="index-ZFTP_005fCOUNT"></span>

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.

------------------------------------------------------------------------

<span id="Problems"></span>

### 22.32.4 Problems

<span id="index-zftp_002c-problems"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fzle-Module"></span> <span
id="The-zsh_002fzle-Module-1"></span>

## 22.33 The zsh/zle Module

The zsh/zle module contains the Zsh Line Editor. See [Zsh Line
Editor](Zsh-Line-Editor.html#Zsh-Line-Editor).

------------------------------------------------------------------------

<span id="The-zsh_002fzleparameter-Module"></span> <span
id="The-zsh_002fzleparameter-Module-1"></span>

## 22.34 The zsh/zleparameter Module

<span id="index-parameters_002c-special-2"></span>

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](Zsh-Line-Editor.html#Zsh-Line-Editor)).

<span id="index-keymaps-2"></span>

keymaps

This array contains the names of the keymaps currently defined.

<span id="index-widgets-1"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fzprof-Module"></span> <span
id="The-zsh_002fzprof-Module-1"></span>

## 22.35 The zsh/zprof Module

<span id="index-functions_002c-profiling"></span>

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.

<span id="index-zprof"></span>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fzpty-Module"></span> <span
id="The-zsh_002fzpty-Module-1"></span>

## 22.36 The zsh/zpty Module

The zsh/zpty module offers one builtin:

<span id="index-zpty"></span>

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](Zsh-Line-Editor.html#Zle-Builtins)) or manipulated with
sysread and syswrite (see [The zsh/system
Module](#The-zsh_002fsystem-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.

------------------------------------------------------------------------

<span id="The-zsh_002fzselect-Module"></span> <span
id="The-zsh_002fzselect-Module-1"></span>

## 22.37 The zsh/zselect Module

The zsh/zselect module makes available one builtin command:

<span id="index-zselect"></span> <span
id="index-select_002c-system-call"></span> <span
id="index-file-descriptors_002c-waiting-for"></span>

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 system’s
documentation for 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,

<div class="example">

```zsh
zselect -t 0 -r 0 -w 1
```

</div>

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.

------------------------------------------------------------------------

<span id="The-zsh_002fzutil-Module"></span> <span
id="The-zsh_002fzutil-Module-1"></span>

## 22.38 The zsh/zutil Module

<span id="index-builtins_002c-utility"></span>

The zsh/zutil module only adds some builtins:

<span id="index-zstyle"></span>

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* <span
id="index-preferred_002dprecipitation_002c-example-style"></span> <span
id="index-weather_002c-example-function"></span>

For example, a fictional ‘weather’ plugin might state in its
documentation that it looks up the preferred-precipitation style under
the ‘:weather:`continent`:`day-of-the-week`:`phase-of-the-moon`’
context. According to this, you might set the following in your zshrc:

<div class="example">

```zsh
zstyle ':weather:europe:*' preferred-precipitation rain
zstyle ':weather:*:Sunday:*' preferred-precipitation snow
```

</div>

Then the plugin would run under the hood a command such as

<div class="example">

```zsh
zstyle -s ":weather:${continent}:${day_of_week}:${moon_phase}" preferred-precipitation REPLY
```

</div>

in order to retrieve your preference into the scalar variable $REPLY. On
Sundays $REPLY would be set to ‘snow’; in Europe it would be set to
‘rain’; and on Sundays in Europe it would be set to ‘snow’ again,
because the patterns ‘:weather:europe:\*’ and ‘:weather:\*:Sunday:\*’
both match the `context` argument to zstyle -s, are equally specific,
and the latter is more specific (because it has more colon-separated
components).

*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 order zstyle will test
them.

If the -L option is given, listing is done in the form of calls to
zstyle. The optional first argument, `metapattern`, is a pattern which
will be matched against the string supplied as `pattern` 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 specific `style` (not a pattern).
-L is not compatible with any other options.

zstyle \[ - \| -- \| -e \] `pattern` `style` `string` ...  
<span id="index-reply_002c-use-of-4"></span>

Defines the given `style` for the `pattern` with the `string`s as the
value. If the -e option is given, the `string`s will be concatenated
(separated by spaces) and the resulting string will be evaluated (in the
same way as it is done by the eval 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 a `pattern` all definitions for that pattern are deleted and if any
`style`s are given, then only those styles are deleted for the
`pattern`.

zstyle -g `name` \[ `pattern` \[ `style` \] \]  
Retrieve a style definition. The `name` is used as the name of an array
in which the results are stored. Without any further arguments, all
patterns defined are returned. With a `pattern` the styles defined for
that pattern are returned and with both a `pattern` and a `style`, 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 parameter `name` is set to the value of the style interpreted as a
string. If the value contains several strings they are concatenated with
spaces (or with the `sep` 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 in `name` 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 if `name` is set to ‘yes’, 1 otherwise.

zstyle -a `context` `style` `name`  
The value is stored in `name` as an array. If `name` 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 any `string` 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 any
`string`s are given the status is zero if and only if at least one of
the `string`s is equal to at least one of the strings in the value. If
the style is defined but doesn’t match, the return status is 1. If the
style is not defined, the status is 2.

The -T option tests the values of the style like -t, but it returns
status zero (rather than 2) if the style is not defined for any matching
pattern.

zstyle -m `context` `style` `pattern`  
Match a value. Returns status zero if the `pattern` matches at least one
of the strings in the value.

<span id="index-zformat"></span>

zformat -f `param` `format` `spec` ...

zformat -F `param` `format` `spec` ...

zformat -a `array` `sep` `spec` ...

This builtin provides 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:

<div class="example">

```zsh
zformat -f REPLY "The answer is '%3(c.yes.no)'." c:3
```

</div>

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.

With -F instead of -f, ternary expressions choose between the ‘true’ or
‘false’ text on the basis of whether the format specifier is present and
non-empty. A test number indicates a minimum width for the value given
in the format specifier. Negative numbers reverse this, so the test is
for whether the value exceeds a maximum width.

The 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`.

<span id="index-zregexparse"></span>

zregexparse

This implements some internals of the \_regex_arguments function.

<span id="index-zparseopts"></span>

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`+  
The `name` 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 in `name`; for example, a ‘--file’ option is represented by a
`name` of ‘-file’.

If a ‘+’ appears after `name`, the option is appended to `array` 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 the `array` 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 the `name` 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 the `spec`s. If the first such
parameter is ‘-’ or ‘--’, it is removed as well. This is similar to
using the shift builtin.

-E  
This changes the parsing rules to *not* stop at the first string that
isn’t described by one of the `spec`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 a `spec`, 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 the `spec`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 the `spec`s for them is
used. Otherwise the entire array is replaced when any of the `spec`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 calling zparseopts.

-M  
This changes the assignment rules to implement a map among equivalent
option names. If any `spec` uses the ‘=`array`’ form, the string `array`
is interpreted as the name of another `spec`, which is used to choose
where to store the values. If no other `spec` 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,

<div class="example">

```zsh
set -- -a -bx -c y -cz baz -cend
zparseopts a=foo b:=bar c+:=bar
```

</div>

will have the effect of

<div class="example">

```zsh
foo=(-a)
bar=(-b x -c y -c z)
```

</div>

The arguments from ‘baz’ on will not be used.

As an example for the -E option, consider:

<div class="example">

```zsh
set -- -a x -b y -c z arg1 arg2
zparseopts -E -D b:=bar
```

</div>

will have the effect of

<div class="example">

```zsh
bar=(-b y)
set -- -a x -c z arg1 arg2
```

</div>

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:

<div class="example">

```zsh
set -- -a -bx -c y -cz baz -cend
zparseopts -A bar -M a=foo b+: c:=b
```

</div>

to have the effect of

<div class="example">

```zsh
foo=(-a)
bar=(-a '' -b xyz)
```

</div>

------------------------------------------------------------------------

This document was generated on *May 14, 2022* using [*texi2html
5.0*](http://www.nongnu.org/texi2html/).  
Zsh version 5.9, released on May 14, 2022.
