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**Table of Contents**  *generated with [DocToc](https://github.com/thlorenz/doctoc)*

- [17 Shell Builtin Commands](#17-shell-builtin-commands)

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<span id="Shell-Builtin-Commands"></span> <span
id="Shell-Builtin-Commands-1"></span>

# 17 Shell Builtin Commands

<span id="index-builtin-commands"></span> <span
id="index-commands_002c-builtin"></span>

Some shell builtin commands take options as described in individual
entries; these are often referred to in the list below as ‘flags’ to
avoid confusion with shell options, which may also have an effect on the
behaviour of builtin commands. In this introductory section, ‘option’
always has the meaning of an option to a command that should be familiar
to most command line users.

Typically, options are single letters preceded by a hyphen (-). Options
that take an argument accept it either immediately following the option
letter or after white space, for example ‘print -C3 {1..9}’ or ‘print -C
3 {1..9}’ are equivalent. Arguments to options are not the same as
arguments to the command; the documentation indicates which is which.
Options that do not take an argument may be combined in a single word,
for example ‘print -rca – \*’ and ‘print -r -c -a – \*’ are equivalent.

Some shell builtin commands also take options that begin with ‘+’
instead of ‘-’. The list below makes clear which commands these are.

Options (together with their individual arguments, if any) must appear
in a group before any non-option arguments; once the first non-option
argument has been found, option processing is terminated.

All builtin commands other than ‘echo’ and precommand modifiers, even
those that have no options, can be given the argument ‘--’ to terminate
option processing. This indicates that the following words are
non-option arguments, but is otherwise ignored. This is useful in cases
where arguments to the command may begin with ‘-’. For historical
reasons, most builtin commands (including ‘echo’) also recognize a
single ‘-’ in a separate word for this purpose; note that this is less
standard and use of ‘--’ is recommended.

\- `simple command`  
See [Precommand Modifiers](Shell-Grammar.html#Precommand-Modifiers).

<span id="index-_002e"></span>

. `file` \[ `arg` ... \]  
Read commands from `file` and execute them in the current shell
environment.

If `file` does not contain a slash, or if PATH_DIRS is set, the shell
looks in the components of $path to find the directory containing
`file`. Files in the current directory are not read unless ‘.’ appears
somewhere in $path. If a file named ‘`file`.zwc’ is found, is newer than
`file`, and is the compiled form (created with the zcompile builtin) of
`file`, then commands are read from that file instead of `file`.

If any arguments `arg` are given, they become the positional parameters;
the old positional parameters are restored when the `file` is done
executing. However, if no arguments are given, the positional parameters
remain those of the calling context, and no restoring is done.

If `file` was not found the return status is 127; if `file` was found
but contained a syntax error the return status is 126; else the return
status is the exit status of the last command executed.

<span id="index-_003a"></span> <span
id="index-expanding-parameters"></span> <span
id="index-parameters_002c-expanding"></span> <span
id="index-doing-nothing"></span>

: \[ `arg` ... \]  
This command does nothing, although normal argument expansions is
performed which may have effects on shell parameters. A zero exit status
is returned.

<span id="index-alias"></span> <span
id="index-aliases_002c-defining"></span> <span
id="index-aliases_002c-listing"></span>

alias \[ {+\|-}gmrsL \] \[ `name`\[=`value`\] ... \]  
For each `name` with a corresponding `value`, define an alias with that
value. A trailing space in `value` causes the next word to be checked
for alias expansion. If the -g flag is present, define a global alias;
global aliases are expanded even if they do not occur in command
position:

<div class="example">

```zsh
% perldoc --help 2>&1 | grep 'built-in functions'
    -f   Search Perl built-in functions
% alias -g HG='--help 2>&1 | grep'
% perldoc HG 'built-in functions'
    -f   Search Perl built-in functions
```

</div>

If the -s flag is present, define a suffix alias: if the command word on
a command line is in the form ‘`text`.`name`’, where `text` is any
non-empty string, it is replaced by the text ‘`value` `text`.`name`’.
Note that `name` is treated as a literal string, not a pattern. A
trailing space in `value` is not special in this case. For example,

<div class="example">

```zsh
alias -s ps='gv --'
```

</div>

will cause the command ‘\*.ps’ to be expanded to ‘gv – \*.ps’. As alias
expansion is carried out earlier than globbing, the ‘\*.ps’ will then be
expanded. Suffix aliases constitute a different name space from other
aliases (so in the above example it is still possible to create an alias
for the command ps) and the two sets are never listed together.

For each `name` with no `value`, print the value of `name`, if any. With
no arguments, print all currently defined aliases other than suffix
aliases. If the -m flag is given the arguments are taken as patterns
(they should be quoted to preserve them from being interpreted as glob
patterns), and the aliases matching these patterns are printed. When
printing aliases and one of the -g, -r or -s flags is present, restrict
the printing to global, regular or suffix aliases, respectively; a
regular alias is one which is neither a global nor a suffix alias. Using
‘+’ instead of ‘-’, or ending the option list with a single ‘+’,
prevents the values of the aliases from being printed.

If the -L flag is present, then print each status is nonzero if a `name`
(with no `value`) is given for which no alias has been defined.

For more on aliases, include common problems, see
[Aliasing](Shell-Grammar.html#Aliasing).

<span id="index-autoload"></span> <span
id="index-functions_002c-autoloading-1"></span> <span
id="index-autoloading-functions-1"></span>

autoload \[ {+\|-}RTUXdkmrtWz \] \[ -w \] \[ `name` ... \]  
<span id="index-fpath_002c-searching"></span>

See the section ‘Autoloading Functions’ in
[Functions](Functions.html#Functions) for full details. The fpath
parameter will be searched to find the function definition when the
function is first referenced.

If `name` consists of an absolute path, the function is defined to load
from the file given (searching as usual for dump files in the given
location). The name of the function is the basename (non-directory part)
of the file. It is normally an error if the function is not found in the
given location; however, if the option -d is given, searching for the
function defaults to $fpath. If a function is loaded by absolute path,
any functions loaded from it that are marked for autoload without an
absolute path have the load path of the parent function temporarily
prepended to $fpath.

If the option -r or -R is given, the function is searched for
immediately and the location is recorded internally for use when the
function is executed; a relative path is expanded using the value of
$PWD. This protects against a change to $fpath after the call to
autoload. With -r, if the function is not found, it is silently left
unresolved until execution; with -R, an error message is printed and
command processing aborted immediately the search fails, i.e. at the
autoload command rather than at function execution..

The flag -X may be used only inside a shell function. It causes the
calling function to be marked for autoloading and then immediately
loaded and executed, with the current array of positional parameters as
arguments. This replaces the previous definition of the function. If no
function definition is found, an error is printed and the function
remains undefined and marked for autoloading. If an argument is given,
it is used as a directory (i.e. it does not include the name of the
function) in which the function is to be found; this may be combined
with the -d option to allow the function search to default to $fpath if
it is not in the given location.

The flag +X attempts to load each `name` as an autoloaded function, but
does *not* execute it. The exit status is zero (success) if the function
was not previously defined *and* a definition for it was found. This
does *not* replace any existing definition of the function. The exit
status is nonzero (failure) if the function was already defined or when
no definition was found. In the latter case the function remains
undefined and marked for autoloading. If ksh-style autoloading is
enabled, the function created will contain the contents of the file plus
a call to the function itself appended to it, thus giving normal ksh
autoloading behaviour on the first call to the function. If the -m flag
is also given each `name` is treated as a pattern and all functions
already marked for autoload that match the pattern are loaded.

With the -t flag, turn on execution tracing; with -T, turn on execution
tracing only for the current function, turning it off on entry to any
called functions that do not also have tracing enabled.

With the -U flag, alias expansion is suppressed when the function is
loaded.

With the -w flag, the `name`s are taken as names of files compiled with
the zcompile builtin, and all functions defined in them are marked for
autoloading.

The flags -z and -k mark the function to be autoloaded using the zsh or
ksh style, as if the option KSH_AUTOLOAD were unset or were set,
respectively. The flags override the setting of the option at the time
the function is loaded.

Note that the autoload command makes no attempt to ensure the shell
options set during the loading or execution of the file have any
particular value. For this, the emulate command can be used:

<div class="example">

```zsh
emulate zsh -c 'autoload -Uz func'
```

</div>

arranges that when `func` is loaded the shell is in native zsh
emulation, and this emulation is also applied when `func` is run.

Some of the functions of autoload are also provided by functions -u or
functions -U, but autoload is a more comprehensive interface.

<span id="index-bg"></span> <span
id="index-jobs_002c-backgrounding"></span>

bg \[ `job` ... \]  
`job` ... &  
Put each specified `job` in the background, or the current job if none
is specified.

bindkey  
See [Zle Builtins](Zsh-Line-Editor.html#Zle-Builtins).

<span id="index-break"></span> <span id="index-exiting-loops"></span>
<span id="index-loops_002c-exiting"></span>

break \[ `n` \]  
Exit from an enclosing for, while, until, select or repeat loop. If an
arithmetic expression `n` is specified, then break `n` levels instead of
just one.

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

builtin `name` \[ `args` ... \]  
Executes the builtin `name`, with the given `args`.

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

bye  
Same as exit.

cap  
See [The zsh/cap Module](Zsh-Modules.html#The-zsh_002fcap-Module).

<span id="index-cd"></span> <span
id="index-directories_002c-changing"></span>

cd \[ -qsLP \] \[ `arg` \]  
cd \[ -qsLP \] `old` `new`  
cd \[ -qsLP \] {+\|-}`n`  
Change the current directory. In the first form, change the current
directory to `arg`, or to the value of $HOME if `arg` is not specified.
If `arg` is ‘-’, change to the previous directory.

Otherwise, if `arg` begins with a slash, attempt to change to the
directory given by `arg`.

If `arg` does not begin with a slash, the behaviour depends on whether
the current directory ‘.’ occurs in the list of directories contained in
the shell parameter cdpath. If it does not, first attempt to change to
the directory `arg` under the current directory, and if that fails but
cdpath is set and contains at least one element attempt to change to the
directory `arg` under each component of cdpath in turn until successful.
If ‘.’ occurs in cdpath, then cdpath is searched strictly in order so
that ‘.’ is only tried at the appropriate point.

The order of testing cdpath is modified if the option POSIX_CD is set,
as described in the documentation for the option.

If no directory is found, the option CDABLE_VARS is set, and a parameter
named `arg` exists whose value begins with a slash, treat its value as
the directory. In that case, the parameter is added to the named

The second form of cd substitutes the string `new` for the string `old`
in the name of the current directory, and tries to change to this new
directory.

The third form of cd extracts an entry from the directory stack, and
changes to that directory. An argument of the form ‘+`n`’ identifies a
stack entry by counting from the left of the list shown by the dirs
command, starting with zero. An argument of the form ‘-`n`’ counts from
the right. If the PUSHD_MINUS option is set, the meanings of ‘+’ and ‘-’
in this context are swapped. If the POSIX_CD option is set, this form of
cd is not recognised and will be interpreted as the first form.

If the -q (quiet) option is specified, the hook function chpwd and the
functions in the array chpwd_functions are not called. This is useful
for calls to cd that do not change the environment seen by an
interactive user.

If the -s option is specified, cd refuses to change the current
directory if the given pathname contains symlinks. If the -P option is
given or the CHASE_LINKS option is set, symbolic links are resolved to
their true values. If the -L option is given symbolic links are retained
in the directory (and not resolved) regardless of the state of the
CHASE_LINKS option.

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

chdir  
Same as cd.

clone  
See [The zsh/clone Module](Zsh-Modules.html#The-zsh_002fclone-Module).

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

command \[ -pvV \] `simple command`  
The simple command argument is taken as an external command instead of a
function or builtin and is executed. If the POSIX_BUILTINS option is
set, builtins will also be executed but certain special properties of
them are suppressed. The -p flag causes a default path to be searched
instead of that in $path. With the -v flag, command is similar to whence
and with -V, it is equivalent to whence -v.

See also [Precommand
Modifiers](Shell-Grammar.html#Precommand-Modifiers).

comparguments  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

compcall  
See [The zsh/compctl
Module](Zsh-Modules.html#The-zsh_002fcompctl-Module).

compctl  
See [The zsh/compctl
Module](Zsh-Modules.html#The-zsh_002fcompctl-Module).

compdescribe  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

compfiles  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

compgroups  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

compquote  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

comptags  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

comptry  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

compvalues  
See [The zsh/computil
Module](Zsh-Modules.html#The-zsh_002fcomputil-Module).

<span id="index-continue"></span> <span
id="index-loops_002c-continuing"></span> <span
id="index-continuing-loops"></span>

continue \[ `n` \]  
Resume the next iteration of the enclosing for, while, until, select or
repeat loop. If an arithmetic expression `n` is specified, break out of
`n`-1 loops and resume at the `n`th enclosing loop.

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

declare  
Same as typeset.

<span id="index-dirs"></span> <span
id="index-directory-stack_002c-printing"></span>

dirs \[ -c \] \[ `arg` ... \]  
dirs \[ -lpv \]  
With no arguments, print the contents of the directory stack.
Directories are added to this stack with the pushd command, and removed
with the cd or popd commands. If arguments are specified, load them onto
the directory stack, replacing anything that was there, and push the
current directory onto the stack.

-c  
clear the directory stack.

-l  
print directory names in full instead of using of using \~ expressions
([Filename Expansion](Expansion.html#Filename-Expansion)).

-p  
print directory entries one per line.

-v  
number the directories in the stack when printing.

<span id="index-disable"></span> <span
id="index-disabling-commands"></span> <span
id="index-commands_002c-disabling"></span>

disable \[ -afmprs \] `name` ...  
’?’  
The pattern character ? wherever it occurs, including when preceding a
parenthesis with KSH_GLOB.

’\*’  
The pattern character \* wherever it occurs, including recursive
globbing and when preceding a parenthesis with KSH_GLOB.

’\[’  
Character classes.

’\<’ (NO_SH_GLOB)  
Numeric ranges.

’\|’ (NO_SH_GLOB)  
Alternation in grouped patterns, case statements, or KSH_GLOB
parenthesised expressions.

’(’ (NO_SH_GLOB)  
Grouping using single parentheses. Disabling this does not disable the
use of parentheses for KSH_GLOB where they are introduced by a special
character, nor for glob qualifiers (use ‘setopt NO_BARE_GLOB_QUAL’ to
disable glob qualifiers that use parentheses only).

’\~’ (EXTENDED_GLOB)  
Exclusion in the form `A`\~`B`.

’^’ (EXTENDED_GLOB)  
Exclusion in the form `A`^`B`.

’#’ (EXTENDED_GLOB)  
The pattern character # wherever it occurs, both for repetition of a
previous pattern and for indicating globbing flags.

’?(’ (KSH_GLOB)  
The grouping form ?(`...`). Note this is also disabled if ’?’ is
disabled.

’\*(’ (KSH_GLOB)  
The grouping form \*(`...`). Note this is also disabled if ’\*’ is
disabled.

’+(’ (KSH_GLOB)  
The grouping form +(`...`).

’!(’ (KSH_GLOB)  
The grouping form !(`...`).

’@(’ (KSH_GLOB)  
The grouping form @(`...`).

<span id="index-disown"></span> <span
id="index-jobs_002c-disowning-1"></span>

disown \[ `job` ... \]

`job` ... &\|

`job` ... &!

no longer report their status, and will not complain if you try to exit
an interactive shell with them running or stopped. If no `job` is
specified, disown the current job.

If the `job`s are currently stopped and the AUTO_CONTINUE option is not
set, a warning is printed containing information about how to make them
running after they have been disowned. If one of the latter two forms is
used, the `job`s will automatically be made running, independent of the
setting of the AUTO_CONTINUE option.

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

echo \[ -neE \] \[ `arg` ... \]

Write each `arg` on the standard output, with a space separating each
one. If the -n flag is not present, print a newline at the end. echo
recognizes the following escape sequences:

\\a  
bell character

\\b  
backspace

\\c  
suppress subsequent characters and final newline

\\e  
escape

\\f  
form feed

\\n  
linefeed (newline)

\\r  
carriage return

\\t  
horizontal tab

\\v  
vertical tab

\\\\  
backslash

\\0`NNN`  
character code in octal

\\x`NN`  
character code in hexadecimal

\\u`NNNN`  
unicode character code in hexadecimal

\\U`NNNNNNNN`  
unicode character code in hexadecimal

<span id="index-BSD_005fECHO_002c-use-of"></span>

The -E flag, or the BSD_ECHO option, can be used to disable these escape
sequences. In the latter case, -e flag can be used to enable them.

Note that for standards compliance a double dash does not terminate
option processing; instead, it is printed directly. However, a single
dash does terminate option processing, so the first dash, possibly
following options, is not printed, but everything following it is
printed as an argument. The single dash behaviour is different printf,
and for a more controllable way of printing text within zsh, see print.

echotc

See [The zsh/termcap
Module](Zsh-Modules.html#The-zsh_002ftermcap-Module).

echoti

See [The zsh/terminfo
Module](Zsh-Modules.html#The-zsh_002fterminfo-Module).

<span id="index-emulate"></span> <span
id="index-compatibility_002c-sh"></span> <span
id="index-compatibility_002c-ksh"></span> <span
id="index-compatibility_002c-csh"></span> <span
id="index-sh_002c-compatibility"></span> <span
id="index-ksh_002c-compatibility"></span> <span
id="index-csh_002c-compatibility"></span>

emulate \[ -lLR \] \[ {zsh\|sh\|ksh\|csh} \[ `flags` ... \] \]

Without any argument print current emulation mode.

With single argument set up zsh options to emulate the specified shell
as much as possible. csh will never be fully emulated. If the argument
is not one of the shells listed above, zsh will be used as a default;
more precisely, the tests performed on the argument are the same as
those used to determine the emulation at startup based on the shell
name, see [Compatibility](Invocation.html#Compatibility) . In addition
to setting shell options, the command also restores the pristine state
of pattern enables, as if all patterns had been enabled using enable -p.

If the emulate command occurs inside a function that has been marked for
execution tracing with functions -t then the xtrace option will be
turned on regardless of emulation mode or other options. Note that code
executed inside the function by the ., source, or eval commands is not
considered to be running directly from the function, hence does not
provoke this behaviour.

are reset to their default value corresponding to the specified
emulation mode, except for certain options describing the interactive
environment; otherwise, only those options likely to cause portability
problems in scripts and functions are altered. If the -L switch is
given, the options LOCAL_OPTIONS, LOCAL_PATTERNS and LOCAL_TRAPS will be
set as well, causing the effects of the emulate command and any setopt,
disable -p or enable -p, and trap commands to be local to the
immediately surrounding shell function, if any; normally these options
are turned off in all emulation modes except ksh. The -L switch is
mutually exclusive with the use of -c in `flags`.

If there is a single argument and the -l switch is given, the options
that would be set or unset (the latter indicated with the prefix ‘no’)
are listed. -l can be combined with -L or -R and the list will be
modified in the appropriate way. Note the list does not depend on the
current setting of options, i.e. it includes all options that may in
principle change, not just those that would actually change.

The `flags` may be any of the invocation-time flags described in
[Invocation](Invocation.html#Invocation), except that ‘-o EMACS’ and ‘-o
VI’ may not be used. Flags such as ‘+r’/‘+o RESTRICTED’ may be
prohibited in some circumstances.

If -c `arg` appears in `flags`, `arg` is evaluated while the requested
emulation is temporarily in effect. In this case the emulation mode and
all options are restored to their previous values before emulate
returns. The -R switch may precede the name of the shell to emulate;
note this has a meaning distinct from including -R in `flags`.

Use of -c enables ‘sticky’ emulation mode for functions defined within
the evaluated expression: the emulation mode is associated thereafter
with the function so that whenever the function is executed the
emulation (respecting the -R switch, if present) and all options are set
(and pattern disables cleared) before entry to the function, and the
state is restored after exit. If the function is called when the sticky
emulation is already in effect, either within an ‘emulate `shell` -c’
expression or within another function with the same sticky emulation,
entry and exit from the function do not cause options to be altered
(except due to standard processing such as the LOCAL_OPTIONS option).
This also applies to functions marked for autoload within the sticky
emulation; the appropriate set of options will be applied at the point
the function is loaded as well as when it is run.

For example:

<div class="example">

```zsh
emulate sh -c 'fni() { setopt cshnullglob; }
fno() { fni; }'
fno
```

</div>

The two functions fni and fno are defined with sticky sh emulation. fno
is then executed, causing options associated with emulations to be set
to their values in sh. fno then calls fni; because fni is also marked
for sticky sh emulation, no option changes take place on entry to or
exit from it. Hence the option cshnullglob, turned off by sh emulation,
will be turned on within fni and remain on return to fno. On exit from
fno, the emulation mode and all options will be restored to the state
they were in before entry to the temporary emulation.

The documentation above is typically sufficient for the intended
environment. More detailed rules follow.

1\.  
The sticky emulation environment provided by ‘emulate `shell` -c’ is
identical to that provided by entry to a function marked for sticky
emulation as a consequence of being defined in such an environment.
Hence, for example, the sticky emulation is inherited by subfunctions
defined within functions with sticky emulation.

2\.  
No change of options takes place on entry to or exit from functions that
are not marked for sticky emulation, other than those that would
normally take place, even if those functions are called within sticky
emulation.

3\.  
No special handling is provided for functions marked for autoload nor
for functions present in wordcode created by the zcompile command.

4\.  
The presence or absence of the -R switch to emulate corresponds to
different sticky emulation modes, so for example ‘emulate sh -c’,
‘emulate -R sh -c’ and ‘emulate csh -c’ are treated as three distinct
sticky emulations.

5\.  
Difference in shell options supplied in addition to the basic emulation
also mean the sticky emulations are different, so for example ‘emulate
zsh -c’ and ‘emulate zsh -o cbases -c’ are treated as distinct sticky
emulations.

<span id="index-enable"></span> <span
id="index-enabling-commands"></span> <span
id="index-commands_002c-enabling"></span>

enable \[ -afmprs \] `name` ...

earlier with disable. The default is to enable builtin commands. The -a
option causes enable to act on regular or global aliases. The -s option
causes enable to act on suffix aliases. The -f option causes enable to
act on shell functions. The -r option causes enable to act on reserved
words. Without arguments printed. With the -m flag the arguments are
taken as patterns disabled with the disable builtin command.

enable -p reenables patterns disabled with disable -p. Note that it does
not override globbing options; for example, ‘enable -p "\~"’ does not
cause the pattern character \~ to be active unless the EXTENDED_GLOB
option is also set. To enable all possible patterns (so that they may be
individually disabled with disable -p), use ‘setopt EXTENDED_GLOB
KSH_GLOB NO_SH_GLOB’.

<span id="index-eval"></span> <span
id="index-evaluating-arguments-as-commands"></span>

eval \[ `arg` ... \]

Read the arguments as input to the shell and execute the resulting
command(s) in the current shell process. The return status is the same
as if the commands had been executed directly by the shell; if there are
no `args` or they contain no commands (i.e. are an empty string or
whitespace) the return status is zero.

exec \[ -cl \] \[ -a `argv0` \] \[ `command` \[ `arg` ... \] \]

Replace the current shell with `command` rather than forking. If
`command` is a shell builtin command or a shell function, the shell
executes it, and exits when the command is complete.

With -c clear the environment; with -l prepend - to the argv\[0\] string
of the command executed (to simulate a login shell); with -a `argv0` set
the argv\[0\] string of the command executed. See [Precommand
Modifiers](Shell-Grammar.html#Precommand-Modifiers).

If the option POSIX_BUILTINS is set, `command` is never interpreted as a
shell builtin command or shell function. This means further precommand
modifiers such as builtin and noglob are also not interpreted within the
shell. Hence `command` is always found by searching the command path.

<span id="index-redirection_002c-current-shell_0027s-I_002fO"></span>

If `command` is omitted but any redirections are specified, then the
redirections will take effect in the current shell.

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

exit \[ `n` \]

Exit the shell with the exit status specified by an arithmetic
expression `n`; if none is specified, use the exit status from the last
command executed. <span id="index-IGNORE_005fEOF_002c-use-of"></span> An
EOF condition will also cause the shell to exit, unless the IGNORE_EOF
option is set.

See notes at the end of [Jobs &
Signals](Jobs-_0026-Signals.html#Jobs-_0026-Signals) for some possibly
unexpected interactions of the exit command with jobs.

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

export \[ `name`\[=`value`\] ... \]

The specified `name`s are marked for automatic export to the environment
of subsequently executed commands. Equivalent to typeset -gx. If a
parameter specified does not already exist, it is created in the global
scope.

<span id="index-false"></span> <span
id="index-doing-nothing_002c-unsuccessfully"></span>

false \[ `arg` ... \]

Do nothing and return an exit status of 1.

<span id="index-fc"></span> <span
id="index-history_002c-editing"></span> <span
id="index-editing-history"></span>

fc \[ -e `ename` \] \[ -s \] \[ -LI \] \[ -m `match` \] \[ `old`=`new`
... \] \[ `first` \[ `last` \] \]

fc -l \[ -LI \] \[ -nrdfEiD \] \[ -t `timefmt` \] \[ -m `match` \]

      \[ `old`=`new` ... \] \[ `first` \[ `last` \] \]

fc -p \[ -a \] \[ `filename` \[ `histsize` \[ `savehistsize` \] \] \]

fc -P

fc -ARWI \[ `filename` \]

The fc command controls the interactive history mechanism. Note that
reading and writing of history options is only performed if the shell is
interactive. Usually this is detected automatically, but it can be
forced by setting the interactive option when starting the shell.

The first two forms of this command select a range of events from
`first` to `last` from the history list. The arguments `first` and
`last` may be specified as a number or as a string. A negative number is
used as an offset to the current history event number. A string
specifies the most recent event beginning with the given string. All
substitutions `old`=`new`, if any, are then performed on the text of the
events.

The range of events selected by numbers can be narrowed further by the
following flags.

-I  
restricts to only internal events (not from $HISTFILE)

-L  
restricts to only local events (not from other shells, see SHARE_HISTORY
in [Description of Options](Options.html#Description-of-Options) – note
that $HISTFILE is considered local when read at startup)

-m  
takes the first argument as a pattern (which should be quoted) and only
the history events matching this pattern are considered

If `first` is not specified, it will be set to -1 (the most recent
event), or to -16 if the -l flag is given. If `last` is not specified,
it will be set to `first`, or to -1 if the -l flag is given. However, if
the current event has added entries to the history with ‘print -s’ or
‘fc -R’, then the default `last` for -l includes all new history entries
since the current event began.

When the -l flag is given, the resulting events are listed on standard
output. Otherwise the editor program specified by -e `ename` is invoked
on a file containing these history events. If -e is not given, the value
of the parameter FCEDIT is used; if that is not set the value of the
parameter EDITOR is used; if that is not set a builtin default, usually
‘vi’ is used. If `ename` is ‘-’, no editor is invoked. When editing is
complete, the edited command is executed.

The flag ‘-s’ is equivalent to ‘-e -’. The flag -r reverses the order of
the events and the flag -n suppresses event numbers when listing.

Also when listing,

-d  
prints timestamps for each event

-f  
prints full time-date stamps in the US ‘`MM`/`DD`/`YY` `hh`:`mm`’ format

-E  
prints full time-date stamps in the European ‘`dd`.`mm`.`yyyy`
`hh`:`mm`’ format

-i  
prints full time-date stamps in ISO8601 ‘`yyyy`-`mm`-`dd` `hh`:`mm`’
format

-t `fmt`  
prints time and date stamps in the given format; `fmt` is formatted with
the strftime function with the zsh extensions described for the
%D{`string`} prompt format in [Prompt
Expansion](Prompt-Expansion.html#Prompt-Expansion). The resulting
formatted string must be no more than 256 characters or will not be
printed

-D  
prints elapsed times; may be combined with one of the options above

<span id="index-history_002c-stack"></span> <span
id="index-stack_002c-history"></span>

‘fc -p’ pushes the current history list onto a stack and switches to a
new history list. If the -a option is also specified, this history list
will be automatically popped when the current function scope is exited,
which is a much better solution than creating a trap function to call
‘fc -P’ manually. If no arguments are specified, the history list is
left empty, $HISTFILE is unset, and $HISTSIZE & $SAVEHIST are set to
their default values. If one argument is given, $HISTFILE is set to that
filename, $HISTSIZE & $SAVEHIST are left unchanged, and the history file
is read in (if it exists) to initialize the new list. If a second
argument is specified, $HISTSIZE & $SAVEHIST are instead set to the
single specified numeric value. Finally, if a third argument is
specified, $SAVEHIST is set to a separate value from $HISTSIZE. You are
free to change these environment values for the new history list however
you desire in order to manipulate the new history list.

‘fc -P’ pops the history list back to an older list saved by ‘fc -p’.
The current list is saved to its $HISTFILE before it is destroyed
(assuming that $HISTFILE and $SAVEHIST are set appropriately, of
course). The values of $HISTFILE, $HISTSIZE, and $SAVEHIST are restored
to the values they had when ‘fc -p’ was called. Note that this
restoration can conflict with making these variables "local", so your
best bet is to avoid local declarations for these variables in functions
that use ‘fc -p’. The one other guaranteed-safe combination is declaring
these variables to be local at the top of your function and using the
automatic option (-a) with ‘fc -p’. Finally, note that it is legal to
manually pop a push marked for automatic popping if you need to do so
before the function exits.

<span id="index-history_002c-file"></span> <span
id="index-file_002c-history"></span>

‘fc -R’ reads the history from the given file, ‘fc -W’ writes the
history out to the given file, and ‘fc -A’ appends the history out to
the given file. If no filename is specified, the $HISTFILE is assumed.
If the -I option is added to -R, only those events that are not already
contained within the internal history list are added. If the -I option
is added to -A or -W, only those events that are new since last
incremental append/write to the history file are appended/written. In
any case, the created file will have no more than $SAVEHIST entries.

<span id="index-fg"></span> <span
id="index-jobs_002c-foregrounding"></span> <span
id="index-jobs_002c-resuming"></span>

fg \[ `job` ... \]

`job` ...

Bring each specified `job` in turn to the foreground. If no `job` is
specified, resume the current job.

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

float \[ {+\|-}Hghlprtux \] \[ {+\|-}EFLRZ \[ `n` \] \] \[
`name`\[=`value`\] ... \]

Equivalent to typeset -E, except that options irrelevant to floating
point numbers are not permitted.

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

functions \[ {+\|-}UkmtTuWz \] \[ -x `num` \] \[ `name` ... \]

functions -c `oldfn` `newfn`

functions -M \[-s\] `mathfn` \[ `min` \[ `max` \[ `shellfn` \] \] \]

functions -M \[ -m `pattern` ... \]

functions +M \[ -m \] `mathfn` ...

Equivalent to typeset -f, with the exception of the -c, -x, -M and -W
options. For functions -u and functions -U, see autoload, which provides
additional options. For functions -t and functions -T, see typeset -f.

The -x option indicates that any functions output will have each leading
tab for indentation, added by the shell to show syntactic structure,
expanded to the given number `num` of spaces. `num` can also be 0 to
suppress all indentation.

The -W option turns on the option WARN_NESTED_VAR for the named function
or functions only. The option is turned off at the start of nested
functions (apart from anonoymous functions) unless the called function
also has the -W attribute.

The -c option causes `oldfn` to be copied to `newfn`. The copy is
efficiently handled internally by reference counting. If `oldfn` was
marked for autoload it is first loaded and if this fails the copy fails.
Either function may subsequently be redefined without affecting the
other. A typical idiom is that `oldfn` is the name of a library shell
function which is then redefined to call newfn, thereby installing a
modified version of the function.

*The* -M *and* +M *flags* <span
id="index-defining-mathematical-functions"></span> <span
id="index-functions_002c-defining-mathematical"></span>

Use of the -M option may not be combined with any of the options handled
by typeset -f.

functions -M `mathfn` defines `mathfn` as the name of a mathematical
function recognised in all forms of arithmetical expressions; see
[Arithmetic
Evaluation](Arithmetic-Evaluation.html#Arithmetic-Evaluation). By
default `mathfn` may take any number of comma-separated arguments. If
`min` is given, it must have exactly `min` args; if `min` and `max` are
both given, it must have at least `min` and at most `max` args. `max`
may be -1 to indicate that there is no upper limit.

By default the function is implemented by a shell function of the same
name; if `shellfn` is specified it gives the name of the corresponding
shell function while `mathfn` remains the name used in arithmetical
expressions. The name of the function in $0 is `mathfn` (not `shellfn`
as would usually be the case), provided the option FUNCTION_ARGZERO is
in effect. The positional parameters in the shell function correspond to
the arguments of the mathematical function call.

The result of the last arithmetical expression evaluated inside the
shell function gives the result of the mathematical function. This is
not limited to arithmetic substitutions of the form $((`...`)), but also
includes arithmetical expressions evaluated in any other way, including
by the let builtin, by ((`...`)) statements, and even by the return
builtin and by array subscripts. Therefore, care must be taken not to
use syntactical constructs that perform arithmetic evaluation after
evaluating what is to be the result of the function. For example:

<span id="index-zmath_005fcube"></span> <span id="index-cube"></span>

<div class="example">

```zsh
# WRONG
zmath_cube() {
  (( $1 * $1 * $1 ))
  return 0
}
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))
```

</div>

This will print ‘0’ because of the return.

Commenting the return out would lead to a different problem: the
((`...`)) statement would become the last statement in the function, so
the *return status* ($?) of the function would be non-zero (indicating
failure) whenever the *arithmetic result* of the function would happen
to be zero (numerically):

<div class="example">

```zsh
# WRONG
zmath_cube() {
  (( $1 * $1 * $1 ))
}
functions -M cube 1 1 zmath_cube
print $(( cube(0) ))
```

</div>

Instead, the true builtin can be used:

<div class="example">

```zsh
# RIGHT
zmath_cube() {
  (( $1 * $1 * $1 ))
  true
}
functions -M cube 1 1 zmath_cube
print $(( cube(3) ))
```

</div>

If the additional option -s is given to functions -M, the argument to
the function is a single string: anything between the opening and
matching closing parenthesis is passed to the function as a single
argument, even if it includes commas or white space. The minimum and
maximum argument specifiers must therefore be 1 if given. An empty
argument list is passed as a zero-length string. Thus, the following
string function takes a single argument, including the commas, and
prints 11:

<div class="example">

```zsh
stringfn() { (( $#1 )); true }
functions -Ms stringfn
print $(( stringfn(foo,bar,rod) ))
```

</div>

functions -M with no arguments lists all such user-defined functions in
the same form as a definition. With the additional option -m and a list
of arguments, all functions whose `mathfn` matches one of the pattern
arguments are listed.

function +M removes the list of mathematical functions; with the
additional option -m the arguments are treated as patterns and all
functions whose `mathfn` matches the pattern are removed. Note that the
shell function implementing the behaviour is not removed (regardless of
whether its name coincides with `mathfn`).

getcap

See [The zsh/cap Module](Zsh-Modules.html#The-zsh_002fcap-Module).

<span id="index-getln"></span> <span
id="index-line_002c-reading"></span> <span
id="index-reading-a-line"></span>

getln \[ -AclneE \] `name` ...

Read the top value from the buffer stack and put it in the shell
parameter `name`. Equivalent to read -zr.

<span id="index-getopts"></span> <span
id="index-options_002c-processing"></span>

getopts `optstring` `name` \[ `arg` ... \]

Checks the `arg`s for legal options. If the `arg`s are omitted, use the
positional parameters. A valid option argument begins with a ‘+’ or a
‘-’. An argument not beginning with a ‘+’ or a ‘-’, or the argument
‘--’, ends the options. Note that a single ‘-’ is not considered a valid
option argument. `optstring` contains the letters that getopts
recognizes. If a letter is followed by a ‘:’, that option requires an
argument. The options can be separated from the argument by blanks.

Each time it is invoked, getopts places the option letter it finds in
the shell parameter `name`, prepended with a ‘+’ when `arg` begins with
a ‘+’. The index of the next `arg` is stored in OPTIND. The option
argument, if any, is stored in OPTARG. <span
id="index-OPTIND_002c-use-of"></span> <span
id="index-OPTARG_002c-use-of"></span>

The first option to be examined may be changed by explicitly assigning
to OPTIND. OPTIND has an initial value of 1, and is normally set to 1
upon entry to a shell function and restored upon exit. (The
POSIX_BUILTINS option disables this, and also changes the way the value
is calculated to match other shells.) OPTARG is not reset and retains
its value from the most recent call to getopts. If either of OPTIND or
OPTARG is explicitly unset, it remains unset, and the index or option
argument is not stored. The option itself is still stored in `name` in
this case.

A leading ‘:’ in `optstring` causes getopts to store the letter of any
invalid option in OPTARG, and to set `name` to ‘?’ for an unknown option
and to ‘:’ when a required argument is missing. Otherwise, getopts sets
`name` to ‘?’ and prints an error message when an option is invalid. The
exit status is nonzero when there are no more options.

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

hash \[ -Ldfmrv \] \[ `name`\[=`value`\] \] ...

hash can be used to directly modify the contents of the command

A command `name` starting with a / is never hashed, whether by explicit
use of the hash command or otherwise. Such a command is always found by
direct look up in the file system.

Given no arguments, and neither the -r or -f options,

It will be subsequently rebuilt in the normal fashion. all the absolute
directories in the PATH, These two options cannot be used with any
arguments.

The -m option causes the arguments to be taken as patterns matching
those patterns are printed. This is the only way to display

For each `name` with a corresponding `value`, put ‘`name`’ in whenever
‘`name`’ is used as a command argument, the shell will try to execute
the file given by ‘`value`’. that ‘`value`’ may be referred to as
‘\~`name`’.

For each `name` with no checking what the appropriate value is in the
normal manner for

added by explicit specification. If has no effect if used with -f.

the form of a call to hash.

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

history

Same as fc -l.

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

integer \[ {+\|-}Hghlprtux \] \[ {+\|-}LRZi \[ `n` \] \] \[
`name`\[=`value`\] ... \]

Equivalent to typeset -i, except that options irrelevant to integers are
not permitted.

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

jobs \[ -dlprs \] \[ `job` ... \]

jobs -Z `string`

Lists information about each given job, or all jobs if `job` is omitted.
The -l flag lists process IDs, and the -p flag lists process groups. If
the -r flag is specified only running jobs will be listed and if the -s
flag is given only stopped jobs are shown. If the -d flag is given, the
directory from which the job was started (which may not be the current
directory of the job) will also be shown.

The -Z option replaces the shell’s argument and environment space with
the given string, truncated if necessary to fit. This will normally be
visible in ps (ps(1)) listings. This feature is typically used by
daemons, to indicate their state.

Full job control is only available in the top-level interactive shell,
not in commands run in the left hand side of pipelines or within the
(`...`) construct. However, a snapshot of the job state at that point is
taken, so it is still possible to use the jobs builtin, or any parameter
providing job information. This gives information about the state of
jobs at the point the subshell was created. If background processes are
created within the subshell, then instead information about those
processes is provided.

For example,

<div class="example">

```zsh
sleep 10 &    # Job in background
(             # Shell forks
jobs          # Shows information about "sleep 10 &"
sleep 5 &     # Process in background (no job control)
jobs          # Shows information about "sleep 5 &"
)
```

</div>

<span id="index-kill"></span> <span id="index-killing-jobs"></span>
<span id="index-jobs_002c-killing"></span>

kill \[ -s `signal_name` \| -n `signal_number` \| -`sig` \] `job` ...

kill -l \[ `sig` ... \]

Sends either SIGTERM or the specified signal to the given jobs or
processes. Signals are given by number or by names, with or without the
‘SIG’ prefix. If the signal being sent is not ‘KILL’ or ‘CONT’, then the
job will be sent a ‘CONT’ signal if it is stopped. The argument `job`
can be the process ID of a job not in the job list. In the second form,
kill -l, if `sig` is not specified the signal names are listed.
Otherwise, for each `sig` that is a name, the corresponding signal
number is listed. For each `sig` that is a signal number or a number
representing the exit status of a process which was terminated or
stopped by a signal the name of the signal is printed.

On some systems, alternative signal names are allowed for a few signals.
Typical examples are SIGCHLD and SIGCLD or SIGPOLL and SIGIO, assuming
they correspond to the same signal number. kill -l will only list the
preferred form, however kill -l `alt` will show if the alternative form
corresponds to a signal number. For example, under Linux kill -l IO and
kill -l POLL both output 29, hence kill -IO and kill -POLL have the same
effect.

Many systems will allow process IDs to be negative to kill a process
group or zero to kill the current process group.

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

let `arg` ...

Evaluate each `arg` as an arithmetic expression. See [Arithmetic
Evaluation](Arithmetic-Evaluation.html#Arithmetic-Evaluation) for a
description of arithmetic expressions. The exit status is 0 if the value
of the last expression is nonzero, 1 if it is zero, and 2 if an error
occurred.

<span id="index-limit"></span> <span id="index-resource-limits"></span>
<span id="index-limits_002c-resource"></span>

limit \[ -hs \] \[ `resource` \[ `limit` \] \] ...

Set or display resource limits. Unless the -s flag is given, the limit
applies only the children of the shell. If -s is given without other
arguments, the resource limits of the current shell is set to the
previously set resource limits of the children.

If `limit` is not specified, print the current limit placed on
`resource`, otherwise set the limit to the specified value. If the -h
flag is given, use hard limits instead of soft limits. If no `resource`
is given, print all limits.

When looping over multiple resources, the shell will abort immediately
if it detects a badly formed argument. However, if it fails to set a
limit for some other reason it will continue trying to set the remaining
limits.

`resource` can be one of:

addressspace  
Maximum amount of address space used.

aiomemorylocked  
Maximum amount of memory locked in RAM for AIO operations.

aiooperations  
Maximum number of AIO operations.

cachedthreads  
Maximum number of cached threads.

coredumpsize  
Maximum size of a core dump.

cputime  
Maximum CPU seconds per process.

datasize  
Maximum data size (including stack) for each process.

descriptors  
Maximum value for a file descriptor.

filesize  
Largest single file allowed.

kqueues  
Maximum number of kqueues allocated.

maxproc  
Maximum number of processes.

maxpthreads  
Maximum number of threads per process.

memorylocked  
Maximum amount of memory locked in RAM.

memoryuse  
Maximum resident set size.

msgqueue  
Maximum number of bytes in POSIX message queues.

posixlocks  
Maximum number of POSIX locks per user.

pseudoterminals  
Maximum number of pseudo-terminals.

resident  
Maximum resident set size.

sigpending  
Maximum number of pending signals.

sockbufsize  
Maximum size of all socket buffers.

stacksize  
Maximum stack size for each process.

swapsize  
Maximum amount of swap used.

vmemorysize  
Maximum amount of virtual memory.

Which of these resource limits are available depends on the system.
`resource` can be abbreviated to any unambiguous prefix. It can also be
an integer, which corresponds to the integer defined for the resource by
the operating system.

If argument corresponds to a number which is out of the range of the
resources configured into the shell, the shell will try to read or write
the limit anyway, and will report an error if this fails. As the shell
does not store such resources internally, an attempt to set the limit
will fail unless the -s option is present.

`limit` is a number, with an optional scaling factor, as follows:

`n`h  
hours

`n`k  
kilobytes (default)

`n`m  
megabytes or minutes

`n`g  
gigabytes

\[`mm`:\]`ss`  
minutes and seconds

The limit command is not made available by default when the shell starts
in a mode emulating another shell. It can be made available with the
command ‘zmodload -F zsh/rlimits b:limit’.

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

local \[ {+\|-}AHUahlprtux \] \[ {+\|-}EFLRZi \[ `n` \] \] \[
`name`\[=`value`\] ... \]

Same as typeset, except that the options -g, and -f are not permitted.
In this case the -x option does not force the use of -g, i.e. exported
variables will be local to functions.

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

logout \[ `n` \]

Same as exit, except that it only works in a login shell.

noglob `simple command`

See [Precommand Modifiers](Shell-Grammar.html#Precommand-Modifiers).

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

popd \[ -q \] \[ {+\|-}`n` \]

Remove an entry from the directory stack, and perform a cd to the new
top directory. With no argument, the current top entry is removed. An
argument of the form ‘+`n`’ identifies a stack entry by counting from
the left of the list shown by the dirs command, starting with zero. An
argument of the form -`n` counts from the right. <span
id="index-PUSHD_005fMINUS_002c-use-of-1"></span> If the PUSHD_MINUS
option is set, the meanings of ‘+’ and ‘-’ in this context are swapped.

If the -q (quiet) option is specified, the hook function chpwd and the
functions in the array $chpwd_functions are not called, and the new
directory stack is not printed. This is useful for calls to popd that do
not change the environment seen by an interactive user.

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

print \[ -abcDilmnNoOpPrsSz \] \[ -u `n` \] \[ -f `format` \] \[ -C
`cols` \]

      \[ -v `name` \] \[ -xX `tabstop` \] \[ -R \[ -en \]\] \[ `arg` ...
\]

With the ‘-f’ option the arguments are printed as described by printf.
With no flags or with the flag ‘-’, the arguments are printed on the
standard output as described by echo, with the following differences:
the escape sequence ‘\\M-`x`’ (or ‘\\M`x`’) metafies the character `x`
(sets the highest bit), ‘\\C-`x`’ (or ‘\\C`x`’) produces a control
character (‘\\C-@’ and ‘\\C-?’ give the characters NULL and delete), a
character code in octal is represented by ‘\\`NNN`’ (instead of
‘\\0`NNN`’), and ‘\\E’ is a synonym for ‘\\e’. Finally, if not in an
escape sequence, ‘\\’ escapes the following character and is not
printed.

-a  
Print arguments with the column incrementing first. Only useful with the
-c and -C options.

-b  
Recognize all the escape sequences defined for the bindkey command, see
[Zle Builtins](Zsh-Line-Editor.html#Zle-Builtins).

-c  
Print the arguments in columns. Unless -a is also given, arguments are
printed with the row incrementing first.

-C `cols`  
Print the arguments in `cols` columns. Unless -a is also given,
arguments are printed with the row incrementing first.

-D  
Treat the arguments as paths, replacing directory prefixes with \~
expressions corresponding to directory names, as appropriate.

-i  
If given together with -o or -O, sorting is performed
case-independently.

-l  
Print the arguments separated by newlines instead of spaces. Note: if
the list of arguments is empty, print -l will still output one empty
line. To print a possibly-empty list of arguments one per line, use
print -C1, as in ‘print -rC1 – "$list\[@\]"’.

-m  
Take the first argument as a pattern (should be quoted), and remove it
from the argument list together with subsequent arguments that do not
match this pattern.

-n  
Do not add a newline to the output.

-N  
Print the arguments separated and terminated by nulls. Again, print
-rNC1 – "$list\[@\]" is a canonical way to print an arbitrary list as
null-delimited records.

-o  
Print the arguments sorted in ascending order.

-O  
Print the arguments sorted in descending order.

-p  
Print the arguments to the input of the coprocess.

-P  
Perform prompt expansion (see [Prompt
Expansion](Prompt-Expansion.html#Prompt-Expansion)). In combination with
‘-f’, prompt escape sequences are parsed only within interpolated
arguments, not within the format string.

-r  
Ignore the escape conventions of echo.

-R  
Emulate the BSD echo command, which does not process escape sequences
unless the -e flag is given. The -n flag suppresses the trailing
newline. Only the -e and -n flags are recognized after -R; all other
arguments and options are printed.

-s  
Place the results in the history list instead of on the standard output.
Each argument to the print command is treated as a single word in the
history, regardless of its content.

-S  
Place the results in the history list instead of on the standard output.
In this case only a single argument is allowed; it will be split into
words as if it were a full shell command line. The effect is similar to
reading the line from a history file with the HIST_LEX_WORDS option
active.

-u `n`  
Print the arguments to file descriptor `n`.

-v `name`  
Store the printed arguments as the value of the parameter `name`.

-x `tab-stop`  
Expand leading tabs on each line of output in the printed string
assuming a tab stop every `tab-stop` characters. This is appropriate for
formatting code that may be indented with tabs. Note that leading tabs
of any argument to print, not just the first, are expanded, even if
print is using spaces to separate arguments (the column count is
maintained across arguments but may be incorrect on output owing to
previous unexpanded tabs).

The start of the output of each print command is assumed to be aligned
with a tab stop. Widths of multibyte characters are handled if the
option MULTIBYTE is in effect. This option is ignored if other
formatting options are in effect, namely column alignment or printf
style, or if output is to a special location such as shell history or
the command line editor.

-X `tab-stop`  
This is similar to -x, except that all tabs in the printed string are
expanded. This is appropriate if tabs in the arguments are

-z  
Push the arguments onto the editing buffer stack, separated by spaces.

If any of ‘-m’, ‘-o’ or ‘-O’ are used in combination with ‘-f’ and there
are no arguments (after the removal process in the case of ‘-m’) then
nothing is printed.

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

printf \[ -v `name` \] `format` \[ `arg` ... \]

Print the arguments according to the format specification. Formatting
rules are the same as used in C. The same escape sequences as for echo
are recognised in the format. All C conversion specifications ending in
one of csdiouxXeEfgGn are handled. In addition to this, ‘%b’ can be used
instead of ‘%s’ to cause escape sequences in the argument to be
recognised and ‘%q’ can be used to quote the argument in such a way that
allows it to be reused as shell input. With the numeric format
specifiers, if the corresponding argument starts with a quote character,
the numeric value of the following character is used as the number to
print; otherwise the argument is evaluated as an arithmetic expression.
See [Arithmetic
Evaluation](Arithmetic-Evaluation.html#Arithmetic-Evaluation) for a
description of arithmetic expressions. With ‘%n’, the corresponding
argument is taken as an identifier which is created as an integer
parameter.

Normally, conversion specifications are applied to each argument in
order but they can explicitly specify the `n`th argument is to be used
by replacing ‘%’ by ‘%`n`$’ and ‘\*’ by ‘\*`n`$’. It is recommended that
you do not mix references of this explicit style with the normal style
and the handling of such mixed styles may be subject to future change.

If arguments remain unused after formatting, the format string is reused
until all arguments have been consumed. With the print builtin, this can
be suppressed by using the -r option. If more arguments are required by
the format than have been specified, the behaviour is as if zero or an
empty string had been specified as the argument.

The -v option causes the output to be stored as the value of the
parameter `name`, instead of printed. If `name` is an array and the
format string is reused when consuming arguments then one array element
will be used for each use of the format string.

<span id="index-pushd"></span> <span
id="index-PUSHD_005fTO_005fHOME_002c-use-of"></span> <span
id="index-PUSHD_005fMINUS_002c-use-of-2"></span> <span
id="index-CDABLE_005fVARS_002c-use-of"></span> <span
id="index-PUSHD_005fSILENT_002c-use-of"></span>

pushd \[ -qsLP \] \[ `arg` \]

pushd \[ -qsLP \] `old` `new`

pushd \[ -qsLP \] {+\|-}`n`

Change the current directory, and push the old current directory onto
the directory stack. In the first form, change the current directory to
`arg`. If `arg` is not specified, change to the second directory on the
stack (that is, exchange the top two entries), or change to $HOME if the
PUSHD_TO_HOME option is set or if there is only one entry on the stack.
Otherwise, `arg` is interpreted as it would be by cd. The meaning of
`old` and `new` in the second form is also the same as for cd.

The third form of pushd changes directory by rotating the directory
list. An argument of the form ‘+`n`’ identifies a stack entry by
counting from the left of the list shown by the dirs command, starting
with zero. An argument of the form ‘-`n`’ counts from the right. If the
PUSHD_MINUS option is set, the meanings of ‘+’ and ‘-’ in this context
are swapped.

If the -q (quiet) option is specified, the hook function chpwd and the
functions in the array $chpwd_functions are not called, and the new
directory stack is not printed. This is useful for calls to pushd that
do not change the environment seen by an interactive user.

If the option -q is not specified and the shell option PUSHD_SILENT is
not set, the directory stack will be printed after a pushd is performed.

The options -s, -L and -P have the same meanings as for the cd builtin.

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

pushln \[ `arg` ... \]

Equivalent to print -nz.

<span id="index-pwd"></span> <span
id="index-CHASE_005fLINKS_002c-use-of"></span>

pwd \[ -rLP \]

Print the absolute pathname of the current working directory. If the -r
or the -P flag is specified, or the CHASE_LINKS option is set and the -L
flag is not given, the printed path will not contain symbolic links.

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

r

Same as fc -e -.

<span id="index-read"></span> <span id="index-IFS_002c-use-of-2"></span>

read \[ -rszpqAclneE \] \[ -t \[ `num` \] \] \[ -k \[ `num` \] \] \[ -d
`delim` \]

     \[ -u `n` \] \[ \[`name`\]\[?`prompt`\] \] \[ `name` ... \]

<span id="index-REPLY_002c-use-of-2"></span> <span
id="index-reply_002c-use-of-1"></span>

Read one line and break it into fields using the characters in $IFS as
separators, except as noted below. The first field is assigned to the
first `name`, the second field to the second `name`, etc., with leftover
fields assigned to the last `name`. If `name` is omitted then REPLY is
used for scalars and reply for arrays.

-r  
Raw mode: a ‘\\’ at the end of a line does not signify line continuation
and backslashes in the line don’t quote the following character and are
not removed.

-s  
Don’t echo back characters if reading from the terminal.

-q  
Read only one character from the terminal and set `name` to ‘y’ if this
character was ‘y’ or ‘Y’ and to ‘n’ otherwise. With this flag set the
return status is zero only if the character was ‘y’ or ‘Y’. This option
may be used with a timeout (see -t); if the read times out, or
encounters end of file, status 2 is returned. Input is read from the
terminal unless one of -u or -p is present. This option may also be used
within zle widgets.

-k \[ `num` \]  
Read only one (or `num`) characters. All are assigned to the first
`name`, without word splitting. This flag is ignored when -q is present.
Input is read from the terminal unless one of -u or -p is present. This
option may also be used within zle widgets.

Note that despite the mnemonic ‘key’ this option does read full
characters, which may consist of multiple bytes if the option MULTIBYTE
is set.

-z  
Read one entry from the editor buffer stack and assign it to the first
`name`, without word splitting. Text is pushed onto the stack with
‘print -z’ or with push-line from the line editor (see [Zsh Line
Editor](Zsh-Line-Editor.html#Zsh-Line-Editor)). This flag is ignored
when the -k or -q flags are present.

-e  
-E  
The input read is printed (echoed) to the standard output. If the -e
flag is used, no input is assigned to the parameters.

-A  
The first `name` is taken as the name of an array and all words are
assigned to it.

-c  
-l  
These flags are allowed only if called inside a function used for
completion (specified with the -K flag to compctl). If the -c flag is
given, the words of the current command are read. If the -l flag is
given, the whole line is assigned as a scalar. If both flags are
present, -l is used and -c is ignored.

-n  
Together with -c, the number of the word the cursor is on is read. With
-l, the index of the character the cursor is on is read. Note that the
command name is word number 1, not word 0, and that when the cursor is
at the end of the line, its character index is the length of the line
plus one.

-u `n`  
Input is read from file descriptor `n`.

-p  
Input is read from the coprocess.

-d `delim`  
Input is terminated by the first character of `delim` instead of by
newline.

-t \[ `num` \]  
Test if input is available before attempting to read. If `num` is
present, it must begin with a digit and will be evaluated to give a
number of seconds, which may be a floating point number; in this case
the read times out if input is not available within this time. If `num`
is not present, it is taken to be zero, so that read returns immediately
if no input is available. If no input is available, return status 1 and
do not set any variables.

This option is not available when reading from the editor buffer with
-z, when called from within completion with -c or -l, with -q which
clears the input queue before reading, or within zle where other
mechanisms should be used to test for input.

Note that read does not attempt to alter the input processing mode. The
default mode is canonical input, in which an entire line is read at a
time, so usually ‘read -t’ will not read anything until an entire line
has been typed. However, when reading from the terminal with -k input is
processed one key at a time; in this case, only availability of the
first character is tested, so that e.g. ‘read -t -k 2’ can still block
on the second character. Use two instances of ‘read -t -k’ if this is
not what is wanted.

If the first argument contains a ‘?’, the remainder of this word is used
as a `prompt` on standard error when the shell is interactive.

The value (exit status) of read is 1 when an end-of-file is encountered,
or when -c or -l is present and the command is not called from a compctl
function, or as described for -q. Otherwise the value is 0.

The behavior of some combinations of the -k, -p, -q, -u and -z flags is
undefined. Presently -q cancels all the others, -p cancels -u, -k
cancels -z, and otherwise -z cancels both -p and -u.

The -c or -l flags cancel any and all of -kpquz.

<span id="index-parameters_002c-marking-readonly"></span>

readonly

Same as typeset -r. With the POSIX_BUILTINS option set, same as typeset
-gr.

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

rehash

Same as hash -r.

<span id="index-return"></span> <span
id="index-functions_002c-returning-from"></span>

return \[ `n` \]

Causes a shell function or ‘.’ script to return to the invoking script
with the return status specified by an arithmetic expression `n`. For
example, the following prints ‘42’:

<div class="example">

```zsh
() { integer foo=40; return "foo + 2" }
echo $?
```

</div>

If `n` is omitted, the return status is that of the last command
executed.

If return was executed from a trap in a TRAP`NAL` function, the effect
is different for zero and non-zero return status. With zero status (or
after an implicit return at the end of the trap), the shell will return
to whatever it was previously processing; with a non-zero status, the
shell will behave as interrupted except that the return status of the
trap is retained. Note that the numeric value of the signal which caused
the trap is passed as the first argument, so the statement ‘return
"128+$1"’ will return the same status as if the signal had not been
trapped.

sched

See [The zsh/sched Module](Zsh-Modules.html#The-zsh_002fsched-Module).

<span id="index-set"></span> <span
id="index-parameters_002c-listing"></span> <span
id="index-parameters_002c-positional"></span> <span
id="index-parameters_002c-setting-array"></span> <span
id="index-array-parameters_002c-setting"></span> <span
id="index-KSH_005fARRAYS_002c-use-of-1"></span>

set \[ {+\|-}`options` \| {+\|-}o \[ `option_name` \] \] ... \[ {+\|-}A
\[ `name` \] \]

    \[ `arg` ... \]

Set the options for the shell and/or set the positional parameters, or
declare and set an array. If the -s option is given, it causes the
specified arguments to be sorted before assigning them to the positional
parameters (or to the array `name` if -A is used). With +s sort
arguments in descending order. For the meaning of the other flags, see
[Options](Options.html#Options). Flags may be specified by name using
the -o option. If no option name is supplied with -o, the current option
states are printed: see the description of setopt below for more
information on the format. With +o they are printed in a form that can
be used as input to the shell.

If the -A flag is specified, `name` is set to an array containing the
given `arg`s; if no `name` is specified, all arrays are printed together
with their values.

If +A is used and `name` is an array, the given arguments will replace
the initial elements of that array; if no `name` is specified, all
arrays are printed without their values.

The behaviour of arguments after -A `name` or +A `name` depends on
whether the option KSH_ARRAYS is set. If it is not set, all arguments
following `name` are treated as values for the array, regardless of
their form. If the option is set, normal option processing continues at
that point; only regular arguments are treated as values for the array.
This means that

<div class="example">

```zsh
set -A array -x -- foo
```

</div>

sets array to ‘-x -- foo’ if KSH_ARRAYS is not set, but sets the array
to foo and turns on the option ‘-x’ if it is set.

If the -A flag is not present, but there are arguments beyond the
options, the positional parameters are set. If the option list (if any)
is terminated by ‘--’, and there are no further arguments, the
positional parameters will be unset.

If no arguments and no ‘--’ are given, then the names and values of all
parameters are printed on the standard output. If the only argument is
‘+’, the names of all parameters are printed.

For historical reasons, ‘set -’ is treated as ‘set +xv’ and ‘set -
`args`’ as ‘set +xv – `args`’ when in any other emulation mode than
zsh’s native mode.

setcap

See [The zsh/cap Module](Zsh-Modules.html#The-zsh_002fcap-Module).

<span id="index-setopt"></span> <span
id="index-options_002c-setting"></span>

setopt \[ {+\|-}`options` \| {+\|-}o `option_name` \] \[ -m \] \[ `name`
... \]

Set the options for the shell. All options specified either with flags
or by name are set.

If no arguments are supplied, the names of all options currently set are
printed. The form is chosen so as to minimize the differences from the
default options for the current emulation (the default emulation being
native zsh, shown as \<Z> in [Description of
Options](Options.html#Description-of-Options)). Options that are on by
default for the emulation are shown with the prefix no only if they are
off, while other options are shown without the prefix no and only if
they are on. In addition to options changed from the default state by
the user, any options activated automatically by the shell (for example,
SHIN_STDIN or INTERACTIVE) will be shown in the list. The format is
further modified by the option KSH_OPTION_PRINT, however the rationale
for choosing options with or without the no prefix remains the same in
this case.

If the -m flag is given the arguments are taken as patterns (which
should be quoted to protect them from filename expansion), and all
options with names matching these patterns are set.

Note that a bad option name does not cause execution of subsequent shell
code to be aborted; this is behaviour is different from that of ‘set
-o’. This is because set is regarded as a special builtin by the POSIX
standard, but setopt is not.

<span id="index-shift"></span> <span
id="index-parameters_002c-positional-1"></span>

shift \[ -p \] \[ `n` \] \[ `name` ... \]

The positional parameters ${`n`+1} ... are renamed to $1 ..., where `n`
is an arithmetic expression that defaults to 1. If any `name`s are given
then the arrays with these names are shifted instead of the positional
parameters.

If the option -p is given arguments are instead removed (popped) from
the end rather than the start of the array.

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

source `file` \[ `arg` ... \]

Same as ‘.’, except that the current directory is always searched and is
always searched first, before directories in $path.

stat

See [The zsh/stat Module](Zsh-Modules.html#The-zsh_002fstat-Module).

<span id="index-suspend"></span> <span
id="index-shell_002c-suspending"></span> <span
id="index-suspending-the-shell"></span>

suspend \[ -f \]

Suspend the execution of the shell (send it a SIGTSTP) until it receives
a SIGCONT. Unless the -f option is given, this will refuse to suspend a
login shell.

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

test \[ `arg` ... \]

\[ \[ `arg` ... \] \]

Like the system version of test. Added for compatibility; use
conditional expressions instead (see [Conditional
Expressions](Conditional-Expressions.html#Conditional-Expressions)). The
main differences between the conditional expression syntax and the test
and \[ builtins are: these commands are not handled syntactically, so
for example an empty variable expansion may cause an argument to be
omitted; syntax errors cause status 2 to be returned instead of a shell
error; and arithmetic operators expect integer arguments rather than
arithmetic expressions.

The command attempts to implement POSIX and its extensions where these
are specified. Unfortunately there are intrinsic ambiguities in the
syntax; in particular there is no distinction between test operators and
strings that resemble them. The standard attempts to resolve these for
small numbers of arguments (up to four); for five or more arguments
compatibility cannot be relied on. Users are urged wherever possible to
use the ‘\[\[’ test syntax which does not have these ambiguities.

<span id="index-times"></span> <span
id="index-shell_002c-timing"></span> <span
id="index-timing-the-shell"></span>

times

Print the accumulated user and system times for the shell and for
processes run from the shell.

<span id="index-trap"></span> <span
id="index-signals_002c-trapping-1"></span> <span
id="index-trapping-signals-1"></span>

trap \[ `arg` \] \[ `sig` ... \]

`arg` is a series of commands (usually quoted to protect it from
immediate evaluation by the shell) to be read and executed when the
shell receives any of the signals specified by one or more `sig` args.
Each `sig` can be given as a number, or as the name of a signal either
with or without the string SIG in front (e.g. 1, HUP, and SIGHUP are all
the same signal).

If `arg` is ‘-’, then the specified signals are reset to their defaults,
or, if no `sig` args are present, all traps are reset.

If `arg` is an empty string, then the specified signals are ignored by
the shell (and by the commands it invokes).

If `arg` is omitted but one or more `sig` args are provided (i.e. the
first argument is a valid signal number or name), the effect is the same
as if `arg` had been specified as ‘-’.

The trap command with no arguments prints a list of commands associated
with each signal.

If `sig` is ZERR then `arg` will be executed after each command with a
nonzero exit status. ERR is an alias for ZERR on systems that have no
SIGERR signal (this is the usual case).

If `sig` is DEBUG then `arg` will be executed before each command if the
option DEBUG_BEFORE_CMD is set (as it is by default), else after each
command. Here, a ‘command’ is what is described as a ‘sublist’ in the
shell grammar, see [Simple Commands &
Pipelines](Shell-Grammar.html#Simple-Commands-_0026-Pipelines). If
DEBUG_BEFORE_CMD is set various additional features are available.
First, it is possible to skip the next command by setting the option
ERR_EXIT; see the description of the ERR_EXIT option in [Description of
Options](Options.html#Description-of-Options). Also, the shell parameter
ZSH_DEBUG_CMD is set to the string corresponding to the command to be
executed following the trap. Note that this string is reconstructed from
the internal format and may not be formatted the same way as the
original text. The parameter is unset after the trap is executed.

If `sig` is 0 or EXIT and the trap statement is executed inside the body
of a function, then the command `arg` is executed after the function
completes. The value of $? at the start of execution is the exit status
of the shell or the return status of the function exiting. If `sig` is 0
or EXIT and the trap statement is not executed inside the body of a
function, then the command `arg` is executed when the shell terminates;
the trap runs before any zshexit hook functions.

ZERR, DEBUG, and EXIT traps are not executed inside other traps. ZERR
and DEBUG traps are kept within subshells, while other traps are reset.

Note that traps defined with the trap builtin are slightly different
from those defined as ‘TRAP`NAL` () { ... }’, as the latter have their
own function environment (line numbers, local variables, etc.) while the
former use the environment of the command in which they were called. For
example,

<div class="example">

```zsh
trap 'print $LINENO' DEBUG
```

</div>

will print the line number of a command executed after it has run, while

<div class="example">

```zsh
TRAPDEBUG() { print $LINENO; }
```

</div>

will always print the number zero.

Alternative signal names are allowed as described under kill above.
Defining a trap under either name causes any trap under an alternative
name to be removed. However, it is recommended that for consistency
users stick exclusively to one name or another.

<span id="index-true"></span> <span
id="index-doing-nothing_002c-successfully"></span>

true \[ `arg` ... \]

Do nothing and return an exit status of 0.

<span id="index-ttyctl"></span> <span
id="index-tty_002c-freezing"></span>

ttyctl \[ -fu \]

The -f option freezes the tty (i.e. terminal or terminal emulator), and
-u unfreezes it. When the tty is frozen, no changes made to the tty
settings by external programs will be honored by the shell, except for
changes in the size of the screen; the shell will simply reset the
settings to their previous values as soon as each command exits or is
suspended. Thus, stty and similar programs have no effect when the tty
is frozen. Freezing the tty does not cause the current state to be
remembered: instead, it causes future changes to the state to be
blocked.

Without options it reports whether the terminal is frozen or not.

Note that, regardless of whether the tty is frozen or not, the shell
needs to change the settings when the line editor starts, so unfreezing
the tty does not guarantee settings made on the command line are
preserved. Strings of commands run between editing the command line will
see a consistent tty state. See also the shell variable STTY for a means
of initialising the tty before running external commands and/or freezing
the tty around a single command.

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

type \[ -wfpamsS \] `name` ...

Equivalent to whence -v.

<span id="index-typeset"></span> <span
id="index-parameters_002c-setting"></span> <span
id="index-parameters_002c-declaring"></span>

typeset \[ {+\|-}AHUaghlmrtux \] \[ {+\|-}EFLRZip \[ `n` \] \]

        \[ + \] \[ `name`\[=`value`\] ... \]

typeset -T \[ {+\|-}Uglrux \] \[ {+\|-}LRZp \[ `n` \] \]

        \[ + \| `SCALAR`\[=`value`\] `array`\[=(`value` ...)\] \[ `sep`
\] \]

typeset -f \[ {+\|-}TUkmtuz \] \[ + \] \[ `name` ... \]

Set or display attributes and values for shell parameters.

Except as noted below for control flags that change the behavior, a
parameter is created for each `name` that does not already refer to one.
When inside a function, a new parameter is created for every `name`
(even those that already exist), and is unset again when the function
completes. See [Local Parameters](Parameters.html#Local-Parameters). The
same rules apply to special shell parameters, which retain their special
attributes when made local.

For each `name`=`value` assignment, the parameter `name` is set to
`value`. If the assignment is omitted and `name` does *not* refer to an
existing parameter, a new parameter is intialized to empty string, zero,
or empty array (as appropriate), *unless* the shell option
TYPESET_TO_UNSET is set. When that option is set, the parameter
attributes are recorded but the parameter remains unset.

If the shell option TYPESET_SILENT is not set, for each remaining `name`
that refers to a parameter that is already set, the name and value of
the parameter are printed in the form of an assignment. Nothing is
printed for newly-created parameters, or when any attribute flags listed
below are given along with the `name`. Using ‘+’ instead of minus to
introduce an attribute turns it off.

If no `name` is present, the names and values of all parameters are
printed. In this case the attribute flags restrict the display to only
those parameters that have the specified attributes, and using ‘+’
rather than ‘-’ to introduce the flag suppresses printing of the values
of parameters when there is no parameter name.

All forms of the command handle scalar assignment. Array assignment is
possible if any of the reserved words declare, export, float, integer,
local, readonly or typeset is matched when the line is parsed (N.B. not
when it is executed). In this case the arguments are parsed as
assignments, except that the ‘+=’ syntax and the GLOB_ASSIGN option are
not supported, and scalar values after = are *not* split further into
words, even if expanded (regardless of the setting of the KSH_TYPESET
option; this option is obsolete).

Examples of the differences between command and reserved word parsing:

<div class="example">

```zsh
# Reserved word parsing
typeset svar=$(echo one word) avar=(several words)
```

</div>

The above creates a scalar parameter svar and an array parameter avar as
if the assignments had been

<div class="example">

```zsh
svar="one word"
avar=(several words)
```

</div>

On the other hand:

<div class="example">

```zsh
# Normal builtin interface
builtin typeset svar=$(echo two words)
```

</div>

The builtin keyword causes the above to use the standard builtin
interface to typeset in which argument parsing is performed in the same
way as for other commands. This example creates a scalar svar containing
the value two and another scalar parameter words with no value. An array
value in this case would either cause an error or be treated as an
obscure set of glob qualifiers.

Arbitrary arguments are allowed if they take the form of assignments
after command line expansion; however, these only perform scalar
assignment:

<div class="example">

```zsh
var='svar=val'
typeset $var
```

</div>

The above sets the scalar parameter svar to the value val. Parentheses
around the value within var would not cause array assignment as they
will be treated as ordinary characters when $var is substituted. Any
non-trivial expansion in the name part of the assignment causes the
argument to be treated in this fashion:

<div class="example">

```zsh
typeset {var1,var2,var3}=name
```

</div>

The above syntax is valid, and has the expected effect of setting the
three parameters to the same value, but the command line is parsed as a
set of three normal command line arguments to typeset after expansion.
Hence it is not possible to assign to multiple arrays by this means.

Note that each interface to any of the commands may be disabled
separately. For example, ‘disable -r typeset’ disables the reserved word
interface to typeset, exposing the builtin interface, while ‘disable
typeset’ disables the builtin. Note that disabling the reserved word
interface for typeset may cause problems with the output of ‘typeset
-p’, which assumes the reserved word interface is available in order to
restore array and associative array values.

Unlike parameter assignment statements, typeset’s exit status on an
assignment that involves a command substitution does not reflect the
exit status of the command substitution. Therefore, to test for an error
in a command substitution, separate the declaration of the parameter
from its initialization:

<div class="example">

```zsh
# WRONG
typeset var1=$(exit 1) || echo "Trouble with var1"

# RIGHT
typeset var1 && var1=$(exit 1) || echo "Trouble with var1"
```

</div>

To initialize a parameter `param` to a command output and mark it
readonly, use typeset -r `param` or readonly `param` after the parameter
assignment statement.

If no attribute flags are given, and either no `name` arguments are
present or the flag +m is used, then each parameter name printed is
preceded by a list of the attributes of that parameter (array,
association, exported, float, integer, readonly, or undefined for
autoloaded parameters not yet loaded). If +m is used with attribute
flags, and all those flags are introduced with +, the matching parameter
names are printed but their values are not.

The following control flags change the behavior of typeset:

\+  
If ‘+’ appears by itself in a separate word as the last option, then the
names of all parameters (functions with -f) are printed, but the values
(function bodies) are not. No `name` arguments may appear, and it is an
error for any other options to follow ‘+’. The effect of ‘+’ is as if
all attribute flags which precede it were given with a ‘+’ prefix. For
example, ‘typeset -U +’ is equivalent to ‘typeset +U’ and displays the
names of all arrays having the uniqueness attribute, whereas ‘typeset -f
-U +’ displays the names of all autoloadable functions. If + is the only
option, then type information (array, readonly, etc.) is also printed
for each parameter, in the same manner as ‘typeset +m "\*"’.

-g  
The -g (global) means that any resulting parameter will not be
restricted to local scope. Note that this does not necessarily mean that
the parameter will be global, as the flag will apply to any existing
parameter (even if unset) from an enclosing function. This flag does not
affect the parameter after creation, hence it has no effect when listing
existing parameters, nor does the flag +g have any effect except in
combination with -m (see below).

-m  
If the -m flag is given the `name` arguments are taken as patterns (use
quoting to prevent these from being interpreted as file patterns). With
no attribute flags, all parameters (or functions with the -f flag) with
matching names are printed (the shell option TYPESET_SILENT is not used
in this case).

If the +g flag is combined with -m, a new local parameter is created for
every matching parameter that is not already local. Otherwise -m applies
all other flags or assignments to the existing parameters.

Except when assignments are made with `name`=`value`, using +m forces
the matching parameters and their attributes to be printed, even inside
a function. Note that -m is ignored if no patterns are given, so
‘typeset -m’ displays attributes but ‘typeset -a +m’ does not.

-p \[ `n` \]  
If the -p option is given, parameters and values are printed in the form
of a typeset command with an assignment, regardless of other flags and
options. Note that the -H flag on parameters is respected; no value will
be shown for these parameters.

-p may be followed by an optional integer argument. Currently only the
value 1 is supported. In this case arrays and associative arrays are
printed with newlines between indented elements for readability.

-T \[ `scalar`\[=`value`\] `array`\[=(`value` ...)\] \[ `sep` \] \]  
This flag has a different meaning when used with -f; see below.
Otherwise the -T option requires zero, two, or three arguments to be
present. With no arguments, the list of parameters created in this
fashion is shown. With two or three arguments, the first two are the
name of a scalar and of an array parameter (in that order) that will be
tied together in the manner of $PATH and $path. The optional third
argument is a single-character separator which will be used to join the
elements of the array to form the scalar; if absent, a colon is used, as
with $PATH. Only the first character of the separator is significant;
any remaining characters are ignored. Multibyte characters are not yet
supported.

Only one of the scalar and array parameters may be assigned an initial
value (the restrictions on assignment forms described above also apply).

Both the scalar and the array may be manipulated as normal. If one is
unset, the other will automatically be unset too. There is no way of
untying the variables without unsetting them, nor of converting the type
of one of them with another typeset command; +T does not work, assigning
an array to `scalar` is an error, and assigning a scalar to `array` sets
it to be a single-element array.

Note that both ‘typeset -xT ...’ and ‘export -T ...’ work, but only the
scalar will be marked for export. Setting the value using the scalar
version causes a split on all separators (which cannot be quoted). It is
possible to apply -T to two previously tied variables but with a
different separator character, in which case the variables remain joined
as before but the separator is changed.

When an existing scalar is tied to a new array, the value of the scalar
is preserved but no attribute other than export will be preserved.

Attribute flags that transform the final value (-L, -R, -Z, -l, -u) are
only applied to the expanded value at the point of a parameter expansion
expression using ‘$’. They are not applied when a parameter is retrieved
internally by the shell for any purpose.

The following attribute flags may be specified:

-A  
The names refer to associative array parameters; see [Array
Parameters](Parameters.html#Array-Parameters).

-L \[ `n` \]  
Left justify and remove leading blanks from the value when the parameter
is expanded. If `n` is nonzero, it defines the width of the field. If
`n` is zero, the width is determined by the width of the value of the
first assignment. In the case of numeric parameters, the length of the
complete value assigned to the parameter is used to determine the width,
not the value that would be output.

The width is the count of characters, which may be multibyte characters
if the MULTIBYTE option is in effect. Note that the screen width of the
character is not taken into account; if this is required, use padding
with parameter expansion flags ${(ml`...`)`...`} as described in
‘Parameter Expansion Flags’ in [Parameter
Expansion](Expansion.html#Parameter-Expansion).

When the parameter is expanded, it is filled on the right with blanks or
truncated if necessary to fit the field. Note truncation can lead to
unexpected results with numeric parameters. Leading zeros are removed if
the -Z flag is also set.

-R \[ `n` \]  
Similar to -L, except that right justification is used; when the
parameter is expanded, the field is left filled with blanks or truncated
from the end. May not be combined with the -Z flag.

-U  
For arrays (but not for associative arrays), keep only the first
occurrence of each duplicated value. This may also be set for tied
parameters (see -T) or colon-separated special parameters like PATH or
FIGNORE, etc. Note the flag takes effect on assignment, and the type of
the variable being assigned to is determinative; for variables with
shared values it is therefore recommended to set the flag for all
interfaces, e.g. ‘typeset -U PATH path’.

This flag has a different meaning when used with -f; see below.

-Z \[ `n` \]  
Specially handled if set along with the -L flag. Otherwise, similar to
-R, except that leading zeros are used for padding instead of blanks if
the first non-blank character is a digit. Numeric parameters are
specially handled: they are always eligible for padding with zeroes, and
the zeroes are inserted at an appropriate place in the output.

-a  
The names refer to array parameters. An array parameter may be created
this way, but it may be assigned to in the typeset statement only if the
reserved word form of typeset is enabled (as it is by default). When
displaying, both normal and associative arrays are shown.

-f  
The names refer to functions rather than parameters. No assignments can
be made, and the only other valid flags are -t, -T, -k, -u, -U and -z.
The flag -t turns on execution tracing for this function; the flag -T
does the same, but turns off tracing for any named (not anonymous)
function called from the present one, unless that function also has the
-t or -T flag. The -u and -U flags cause the function to be marked for
autoloading; -U also causes alias expansion to be suppressed when the
function is loaded. See the description of the ‘autoload’ builtin for
details.

Note that the builtin functions provides the same basic capabilities as
typeset -f but gives access to a few extra options; autoload gives
further additional options for the case typeset -fu and typeset -fU.

-h  
-H  
Hide value: specifies that typeset will not display the value of the
parameter when listing parameters; the display for such parameters is
always as if the ‘+’ flag had been given. Use of the parameter is in
other respects normal, and the option does not apply if the parameter is
specified by name, or by pattern with the -m option. This is on by
default for the parameters in the zsh/parameter and zsh/mapfile modules.
Note, however, that unlike the -h flag this is also useful for
non-special parameters.

-i \[ `n` \]  
Use an internal integer representation. If `n` is nonzero it defines the
output arithmetic base, otherwise it is determined by the first
assignment. Bases from 2 to 36 inclusive are allowed.

-E \[ `n` \]  
Use an internal double-precision floating point representation. On
output the variable will be converted to scientific notation. If `n` is
nonzero it defines the number of significant figures to display; the
default is ten.

-F \[ `n` \]  
Use an internal double-precision floating point representation. On
output the variable will be converted to fixed-point decimal notation.
If `n` is nonzero it defines the number of digits to display after the
decimal point; the default is ten.

-l  
Convert the result to lower case whenever the parameter is expanded. The
value is *not* converted when assigned.

-r  
The given `name`s are marked readonly. Note that if `name` is a special
parameter, the readonly attribute can be turned on, but cannot then be
turned off.

If the POSIX_BUILTINS option is set, the readonly attribute is more
restrictive: unset variables can be marked readonly and cannot then be
set; furthermore, the readonly attribute cannot be removed from any
variable.

It is still possible to change other attributes of the variable though,
some of which like -U or -Z would affect the value. More generally, the
readonly attribute should not be relied on as a security mechanism.

Note that in zsh (like in pdksh but unlike most other shells) it is
still possible to create a local variable of the same name as this is
considered a different variable (though this variable, too, can be
marked readonly). Special variables that have been made readonly retain
their value and readonly attribute when made local.

-t  
Tags the named parameters. Tags have no special meaning to the shell.
This flag has a different meaning when used with -f; see above.

-u  
Convert the result to upper case whenever the parameter is expanded. The
value is *not* converted when assigned. This flag has a different
meaning when used with -f; see above.

-x  
Mark for automatic export to the environment of subsequently executed
commands. If the option GLOBAL_EXPORT is set, this implies the option
-g, unless +g is also explicitly given; in other words the parameter is
not made local to the enclosing function. This is for compatibility with
previous versions of zsh.

<span id="index-ulimit"></span> <span
id="index-resource-limits-1"></span> <span
id="index-limits_002c-resource-1"></span>

ulimit \[ -HSa \] \[ { -bcdfiklmnpqrsTtvwx \| -N `resource` } \[ `limit`
\] ... \]

Set or display resource limits of the shell and the processes started by
the shell. The value of `limit` can be a number in the unit specified
below or one of the values ‘unlimited’, which removes the limit on the
resource, or ‘hard’, which uses the current value of the hard limit on
the resource.

By default, only soft limits are manipulated. If the -H flag is given
use hard limits instead of soft limits. If the -S flag is given together
with the -H flag set both hard and soft limits.

If no options are used, the file size limit (-f) is assumed.

If `limit` is omitted the current value of the specified resources are
printed. When more than one resource value is printed, the limit name
and unit is printed before each value.

When looping over multiple resources, the shell will abort immediately
if it detects a badly formed argument. However, if it fails to set a
limit for some other reason it will continue trying to set the remaining
limits.

Not all the following resources are supported on all systems. Running
ulimit -a will show which are supported.

-a  
Lists all of the current resource limits.

-b  
Socket buffer size in bytes (N.B. not kilobytes)

-c  
512-byte blocks on the size of core dumps.

-d  
Kilobytes on the size of the data segment.

-f  
512-byte blocks on the size of files written.

-i  
The number of pending signals.

-k  
The number of kqueues allocated.

-l  
Kilobytes on the size of locked-in memory.

-m  
Kilobytes on the size of physical memory.

-n  
open file descriptors.

-p  
The number of pseudo-terminals.

-q  
Bytes in POSIX message queues.

-r  
Maximum real time priority. On some systems where this is not available,
such as NetBSD, this has the same effect as -T for compatibility with
sh.

-s  
Kilobytes on the size of the stack.

-T  
The number of simultaneous threads available to the user.

-t  
CPU seconds to be used.

-u  
The number of processes available to the user.

-v  
Kilobytes on the size of virtual memory. On some systems this refers to
the limit called ‘address space’.

-w  
Kilobytes on the size of swapped out memory.

-x  
The number of locks on files.

A resource may also be specified by integer in the form ‘-N `resource`’,
where `resource` corresponds to the integer defined for the resource by
the operating system. This may be used to set the limits for resources
known to the shell which do not correspond to option letters. Such
limits will be shown by number in the output of ‘ulimit -a’.

The number may alternatively be out of the range of limits compiled into
the shell. The shell will try to read or write the limit anyway, and
will report an error if this fails.

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

umask \[ -S \] \[ `mask` \]

The umask is set to `mask`. `mask` can be either an octal number or a
symbolic value as described in the chmod(1) man page. If `mask` is
omitted, the current value is printed. The -S option causes the mask to
be printed as a symbolic value. Otherwise, the mask is printed as an
octal number. Note that in the symbolic form the permissions you specify
are those which are to be allowed (not denied) to the users specified.

<span id="index-aliases_002c-removing"></span>

unalias \[ -ams \] `name` ...

Removes aliases. This command works the same as unhash -a, except that
the -a option removes all regular or global aliases, or with -s all
suffix aliases: in this case no `name` arguments may appear. The options
-m (remove by pattern) and -s without -a (remove listed suffix aliases)
behave as for unhash -a. Note that the meaning of -a is different
between unalias and unhash.

<span id="index-functions_002c-removing"></span> <span
id="index-unfunction"></span>

unfunction

Same as unhash -f.

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

unhash \[ -adfms \] `name` ...

option causes unhash to remove regular or global aliases; note when
removing a global aliases that the argument must be quoted to prevent it
from being expanded before being passed to the command. The -s option
causes unhash to remove suffix aliases. The -f option causes unhash to
remove shell functions. The -d options causes unhash to remove named
directories. If the -m flag is given the arguments are taken as patterns
(should be quoted) and all elements

<span id="index-unlimit"></span> <span
id="index-resource-limits-2"></span> <span
id="index-limits_002c-resource-2"></span>

unlimit \[ -hs \] `resource` ...

The resource limit for each `resource` is set to the hard limit. If the
-h flag is given and the shell has appropriate privileges, the hard
resource limit for each `resource` is removed. The resources of the
shell process are only changed if the -s flag is given.

The unlimit command is not made available by default when the shell
starts in a mode emulating another shell. It can be made available with
the command ‘zmodload -F zsh/rlimits b:unlimit’.

<span id="index-unset"></span> <span
id="index-parameters_002c-unsetting"></span>

unset \[ -fmv \] `name` ...

Each named parameter is unset. Local parameters remain local even if
unset; they appear unset within scope, but the previous value will still
reappear when the scope ends.

Individual elements of associative array parameters may be unset by
using subscript syntax on `name`, which should be quoted (or the entire
command prefixed with noglob) to protect the subscript from filename
generation.

If the -m flag is specified the arguments are taken as patterns (should
be quoted) and all parameters with matching names are unset. Note that
this cannot be used when unsetting associative array elements, as the
subscript will be treated as part of the pattern.

The -v flag specifies that `name` refers to parameters. This is the
default behaviour.

unset -f is equivalent to unfunction.

<span id="index-unsetopt"></span> <span
id="index-options_002c-unsetting"></span>

unsetopt \[ {+\|-}`options` \| {+\|-}o `option_name` \] \[ `name` ... \]

Unset the options for the shell. All options specified either with flags
or by name are unset. If no arguments are supplied, the names of all
options currently unset are printed. If the -m flag is given the
arguments are taken as patterns (which should be quoted to preserve them
from being interpreted as glob patterns), and all options with names
matching these patterns are unset.

vared

See [Zle Builtins](Zsh-Line-Editor.html#Zle-Builtins).

<span id="index-wait"></span> <span id="index-waiting-for-jobs"></span>
<span id="index-jobs_002c-waiting-for"></span>

wait \[ `job` ... \]

Wait for the specified jobs or processes. If `job` is not given then all
currently active child processes are waited for. Each `job` can be
either a job specification or the process ID The exit status from this
command is that of the job waited for. If `job` represents an unknown
job or process ID, a warning is printed (unless the POSIX_BUILTINS
option is set) and the exit status is 127.

It is possible to wait for recent processes (specified by process ID,
not by job) that were running in the background even if the process has
exited. Typically the process ID will be recorded by capturing the value
of the variable $! immediately after the process has been started. There
is a limit on the number of process IDs remembered by the shell; this is
given by the value of the system configuration parameter CHILD_MAX. When
this limit is reached, older process IDs are discarded, least recently
started processes first.

Note there is no protection against the process ID wrapping, i.e. if the
wait is not executed soon enough there is a chance the process waited
for is the wrong one. A conflict implies both process IDs have been
generated by the shell, as other processes are not recorded, and that
the user is potentially interested in both, so this problem is intrinsic
to process IDs.

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

whence \[ -vcwfpamsS \] \[ -x `num` \] `name` ...

For each `name`, indicate how it would be interpreted if used as a
command name.

If `name` is not an alias, built-in command, external command, shell
function, hashed command, or a reserved word, the exit status shall be
non-zero, and — if -v, -c, or -w was passed — a message will be written
to standard output. (This is different from other shells that write that
message to standard error.)

whence is most useful when `name` is only the last path component of a
command, i.e. does not include a ‘/’; in particular, pattern matching
only succeeds if just the non-directory component of the command is
passed.

-v  
Produce a more verbose report.

-c  
Print the results in a csh-like format. This takes precedence over -v.

-w  
For each `name`, print ‘`name`: `word`’ where `word` is one of alias,
builtin, command, function, hashed, reserved or none, according as
`name` corresponds to an alias, a built-in command, an external command,
a shell function, a command defined with the hash builtin, a reserved
word, or is not recognised. This takes precedence over -v and -c.

-f  
Causes the contents of a shell function to be displayed, which would
otherwise not happen unless the -c flag were used.

-p  
Do a path search for `name` even if it is an alias, reserved word, shell
function or builtin.

-a  
Do a search for all occurrences of `name` throughout the command path.
Normally only the first occurrence is printed.

-m  
The arguments are taken as patterns (pattern characters should be
quoted), and the information is displayed for each command matching one
of these patterns.

-s  
If a pathname contains symlinks, print the symlink-free pathname as
well.

-S  
As -s, but if the pathname had to be resolved by following multiple
symlinks, the intermediate steps are printed, too. The symlink resolved
at each step might be anywhere in the path.

-x `num`  
Expand tabs when outputting shell functions using the -c option. This
has the same effect as the -x option to the functions builtin.

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

where \[ -wpmsS \] \[ -x `num` \] `name` ...

Equivalent to whence -ca.

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

which \[ -wpamsS \] \[ -x `num` \] `name` ...

Equivalent to whence -c.

<span id="index-zcompile"></span> <span
id="index-_002ezwc-files_002c-creation"></span> <span
id="index-compilation"></span>

zcompile \[ -U \] \[ -z \| -k \] \[ -R \| -M \] `file` \[ `name` ... \]

zcompile -ca \[ -m \] \[ -R \| -M \] `file` \[ `name` ... \]

zcompile -t `file` \[ `name` ... \]

This builtin command can be used to compile functions or scripts,
storing the compiled form in a file, and to examine files containing the
compiled form. This allows faster autoloading of functions and sourcing
of scripts by avoiding parsing of the text when the files are read.

The first form (without the -c, -a or -t options) creates a compiled
file. If only the `file` argument is given, the output file has the name
‘`file`.zwc’ and will be placed in the same directory as the `file`. The
shell will load the compiled file instead of the normal function file
when the function is autoloaded; see
[Functions](Functions.html#Functions) for a description of how
autoloaded functions are searched. The extension .zwc stands for ‘zsh
word code’.

<span id="index-fpath_002c-with-zcompile"></span>

If there is at least one `name` argument, all the named files are
compiled into the output `file` given as the first argument. If `file`
does not end in .zwc, this extension is automatically appended. Files
containing multiple compiled functions are called ‘digest’ files, and
are intended to be used as elements of the FPATH/fpath special array.

The second form, with the -c or -a options, writes the compiled
definitions for all the named functions into `file`. For -c, the names
must be functions currently defined in the shell, not those marked for
autoloading. Undefined functions that are marked for autoloading may be
written by using the -a option, in which case the fpath is searched and
the contents of the definition files for those functions, if found, are
compiled into `file`. If both -c and -a are given, names of both defined
functions and functions marked for autoloading may be given. In either
case, the functions in files written with the -c or -a option will be
autoloaded as if the KSH_AUTOLOAD option were unset.

The reason for handling loaded and not-yet-loaded functions with
different options is that some definition files for autoloading define
multiple functions, including the function with the same name as the
file, and, at the end, call that function. In such cases the output of
‘zcompile -c’ does not include the additional functions defined in the
file, and any other initialization code in the file is lost. Using
‘zcompile -a’ captures all this extra information.

If the -m option is combined with -c or -a, the `name`s are used as
patterns and all functions whose names match one of these patterns will
be written. If no `name` is given, the definitions of all functions
currently defined or marked as autoloaded will be written.

Note the second form cannot be used for compiling functions that include
redirections as part of the definition rather than within the body of
the function; for example

<div class="example">

```zsh
fn1() { { ... } >~/logfile }
```

</div>

can be compiled but

<div class="example">

```zsh
fn1() { ... } >~/logfile
```

</div>

cannot. It is possible to use the first form of zcompile to compile
autoloadable functions that include the full function definition instead
of just the body of the function.

The third form, with the -t option, examines an existing compiled file.
Without further arguments, the names of the original files compiled into
it are listed. The first line of output shows the version of the shell
which compiled the file and how the file will be used (i.e. by reading
it directly or by mapping it into memory). With arguments, nothing is
output and the return status is set to zero if definitions for *all*
`name`s were found in the compiled file, and non-zero if the definition
for at least one `name` was not found.

Other options:

-U  
Aliases are not expanded when compiling the `name`d files.

-R  
When the compiled file is read, its contents are copied into the shell’s
memory, rather than memory-mapped (see -M). This happens automatically
on systems that do not support memory mapping.

When compiling scripts instead of autoloadable functions, it is often
desirable to use this option; otherwise the whole file, including the
code to define functions which have already been defined, will remain
mapped, consequently wasting memory.

-M  
The compiled file is mapped into the shell’s memory when read. This is
done in such a way that multiple instances of the shell running on the
same host will share this mapped file. If neither -R nor -M is given,
the zcompile builtin decides what to do based on the size of the
compiled file.

-k  
-z  
These options are used when the compiled file contains functions which
are to be autoloaded. If -z is given, the function will be autoloaded as
if the KSH_AUTOLOAD option is *not* set, even if it is set at the time
the compiled file is read, while if the -k is given, the function will
be loaded as if KSH_AUTOLOAD *is* set. These options also take
precedence over any -k or -z options specified to the autoload builtin.
If neither of these options is given, the function will be loaded as
determined by the setting of the KSH_AUTOLOAD option at the time the
compiled file is read.

These options may also appear as many times as necessary between the
listed `name`s to specify the loading style of all following functions,
up to the next -k or -z.

The created file always contains two versions of the compiled format,
one for big-endian machines and one for small-endian machines. The
upshot of this is that the compiled file is machine independent and if
it is read or mapped, only one half of the file is actually used (and
mapped).

zformat

See [The zsh/zutil Module](Zsh-Modules.html#The-zsh_002fzutil-Module).

zftp

See [The zsh/zftp Module](Zsh-Modules.html#The-zsh_002fzftp-Module).

zle

See [Zle Builtins](Zsh-Line-Editor.html#Zle-Builtins).

<span id="index-zmodload"></span> <span
id="index-modules_002c-loading"></span> <span
id="index-loading-modules"></span>

zmodload \[ -dL \] \[ -s \] \[ ... \]

zmodload -F \[ -alLme -P `param` \] `module` \[ \[+-\]`feature` ... \]

zmodload -e \[ -A \] \[ ... \]

zmodload \[ -a \[ -bcpf \[ -I \] \] \] \[ -iL \] ...

zmodload -u \[ -abcdpf \[ -I \] \] \[ -iL \] ...

zmodload -A \[ -L \] \[ `modalias`\[=`module`\] ... \]

zmodload -R `modalias` ...

Performs operations relating to zsh’s loadable modules. Loading of
modules while the shell is running (‘dynamical loading’) is not
available on all operating systems, or on all installations on a
particular operating system, although the zmodload command itself is
always available and can be used to manipulate modules built into
versions of the

Without arguments the names of all currently loaded binary modules are
printed. The -L option causes this list to be in the form of a series of
zmodload commands. Forms with arguments are:

zmodload \[ -is \] `name` ...  
zmodload -u \[ -i \] `name` ...  
In the simplest case, zmodload loads a binary module. The module must be
in a file with a name consisting of the specified `name` followed by a
standard suffix, usually ‘.so’ (‘.sl’ on HPUX). If the module to be
loaded is already loaded the duplicate module is ignored. If zmodload
detects an inconsistency, such as an invalid module name or circular
dependency list, the current code block is aborted. If it is available,
the module is loaded if necessary, while if it is not available,
non-zero status is silently returned. The option -i is accepted for
compatibility but has no effect.

The `name`d module is searched for in the same way a command is, using
$module_path instead of $path. However, the path search is performed
even when the module name contains a ‘/’, which it usually does. There
is no way to prevent the path search.

If the module supports features (see below), zmodload tries to enable
all features when loading a module. If the module was successfully
loaded but not all features could be enabled, zmodload returns status 2.

If the option -s is given, no error is printed if the module was not
available (though other errors indicating a problem with the module are
printed). The return status indicates if the module was loaded. This is
appropriate if the caller considers the module optional.

With -u, zmodload unloads modules. The same `name` must be given that
was given when the module was loaded, but it is not necessary for the
module to exist in the file system. The -i option suppresses the error
if the module is already unloaded (or was never loaded).

Each module has a boot and a cleanup function. The module will not be
loaded if its boot function fails. Similarly a module can only be
unloaded if its cleanup function runs successfully.

zmodload -F \[ -almLe -P `param` \] `module` \[ \[+-\]`feature` ... \]  
zmodload -F allows more selective control over the features provided by
modules. With no options apart from -F, the module named `module` is
loaded, if it was not already loaded, and the list of `feature`s is set
to the required state. If no `feature`s are specified, the module is
loaded, if it was not already loaded, but the state of features is
unchanged. Each feature may be preceded by a + to turn the feature on,
or - to turn it off; the + is assumed if neither character is present.
Any feature not explicitly mentioned is left in its current state; if
the module was not previously loaded this means any such features will
remain disabled. The return status is zero if all features were set, 1
if the module failed to load, and 2 if some features could not be set
(for example, a parameter couldn’t be added because there was a
different parameter of the same name) but the module was loaded.

The standard features are builtins, conditions, parameters and math
functions; these are indicated by the prefix ‘b:’, ‘c:’ (‘C:’ for an
infix condition), ‘p:’ and ‘f:’, respectively, followed by the name that
the corresponding feature would have in the shell. For example,
‘b:strftime’ indicates a builtin named strftime and p:EPOCHSECONDS
indicates a parameter named EPOCHSECONDS. The module may provide other
(‘abstract’) features of its own as indicated by its documentation;
these have no prefix.

With -l or -L, features provided by the module are listed. With -l
alone, a list of features together with their states is shown, one
feature per line. With -L alone, a zmodload -F command that would cause
enabled features of the module to be turned on is shown. With -lL, a
zmodload -F command that would cause all the features to be set to their
current state is shown. If one of these combinations is given with the
option -P `param` then the parameter `param` is set to an array of
features, either features together with their state or (if -L alone is
given) enabled features.

With the option -L the module name may be omitted; then a list of all
enabled features for all modules providing features is printed in the
form of zmodload -F commands. If -l is also given, the state of both
enabled and disabled features is output in that form.

A set of features may be provided together with -l or -L and a module
name; in that case only the state of those features is considered. Each
feature may be preceded by + or - but the character has no effect. If no
set of features is provided, all features are considered.

With -e, the command first tests that the module is loaded; if it is
not, status 1 is returned. If the module is loaded, the list of features
given as an argument is examined. Any feature given with no prefix is
simply tested to see if the module provides it; any feature given with a
prefix + or - is tested to see if is provided and in the given state. If
the tests on all features in the list succeed, status 0 is returned,
else status 1.

With -m, each entry in the given list of features is taken as a pattern
to be matched against the list of features provided by the module. An
initial + or - must be given explicitly. This may not be combined with
the -a option as autoloads must be specified explicitly.

With -a, the given list of features is marked for autoload from the
specified module, which may not yet be loaded. An optional + may appear
before the feature name. If the feature is prefixed with -, any existing
autoload is removed. The options -l and -L may be used to list
autoloads. Autoloading is specific to individual features; when the
module is loaded only the requested feature is enabled. Autoload
requests are preserved if the module is subsequently unloaded until an
explicit ‘zmodload -Fa `module` -`feature`’ is issued. It is not an
error to request an autoload for a feature of a module that is already
loaded.

When the module is loaded each autoload is checked against the features
actually provided by the module; if the feature is not provided the
autoload request is deleted. A warning message is output; if the module
is being loaded to provide a different feature, and that autoload is
successful, there is no effect on the status of the current command. If
the module is already loaded at the time when zmodload -Fa is run, an
error message is printed and status 1 returned.

zmodload -Fa can be used with the -l, -L, -e and -P options for listing
and testing the existence of autoloadable features. In this case -l is
ignored if -L is specified. zmodload -FaL with no module name lists
autoloads for all modules.

Note that only standard features as described above can be autoloaded;
other features require the module to be loaded before enabling.

zmodload -d \[ -L \] \[ `name` \]  
zmodload -d `name` `dep` ...  
zmodload -ud `name` \[ `dep` ... \]  
The -d option can be used to specify module dependencies. The modules
named in the second and subsequent arguments will be loaded before the
module named in the first argument.

With -d and one argument, all dependencies for that module are listed.
With -d and no arguments, all module dependencies are listed. This
listing is by default in a Makefile-like format. The -L option changes
this format to a list of zmodload -d commands.

If -d and -u are both used, dependencies are removed. If only one
argument is given, all dependencies for that module are removed.

zmodload -ab \[ -L \]  
zmodload -ab \[ -i \] `name` \[ `builtin` ... \]  
zmodload -ub \[ -i \] `builtin` ...  
The -ab option defines autoloaded builtins. It defines the specified
`builtin`s. When any of those builtins is called, the module specified
in the first argument is loaded and all its features are enabled (for
selective control of features use ‘zmodload -F -a’ as described above).
If only the `name` is given, one builtin is defined, with the same name
as the module. -i suppresses the error if the builtin is already defined
or autoloaded, but not if another builtin of the same name is already
defined.

With -ab and no arguments, all autoloaded builtins are listed, with the
module name (if different) shown in parentheses after the builtin name.
The -L option changes this format to a list of zmodload -a commands.

If -b is used together with the -u option, it removes builtins
previously defined with -ab. This is only possible if the builtin is not
yet loaded. -i suppresses the error if the builtin is already removed
(or never existed).

Autoload requests are retained if the module is subsequently unloaded
until an explicit ‘zmodload -ub `builtin`’ is issued.

zmodload -ac \[ -IL \]  
zmodload -ac \[ -iI \] `name` \[ `cond` ... \]  
zmodload -uc \[ -iI \] `cond` ...  
The -ac option is used to define autoloaded condition codes. The `cond`
strings give the names of the conditions defined by the module. The
optional -I option is used to define infix condition names. Without this
option prefix condition names are defined.

If given no condition names, all defined names are listed (as a series
of zmodload commands if the -L option is given).

The -uc option removes definitions for autoloaded conditions.

zmodload -ap \[ -L \]  
zmodload -ap \[ -i \] `name` \[ `parameter` ... \]  
zmodload -up \[ -i \] `parameter` ...  
The -p option is like the -b and -c options, but makes zmodload work on
autoloaded parameters instead.

zmodload -af \[ -L \]  
zmodload -af \[ -i \] `name` \[ `function` ... \]  
zmodload -uf \[ -i \] `function` ...  
The -f option is like the -b, -p, and -c options, but makes zmodload
work on autoloaded math functions instead.

zmodload -a \[ -L \]  
zmodload -a \[ -i \] `name` \[ `builtin` ... \]  
zmodload -ua \[ -i \] `builtin` ...  
Equivalent to -ab and -ub.

zmodload -e \[ -A \] \[ `string` ... \]  
The -e option without arguments lists all loaded modules; if the -A
option is also given, module aliases corresponding to loaded modules are
also shown. If arguments are provided, nothing is printed; the return
status is set to zero if all `string`s given as arguments are names of
loaded modules and to one if at least on `string` is not the name of a
loaded module. This can be used to test for the availability of things
implemented by modules. In this case, any aliases are automatically
resolved and the -A flag is not used.

zmodload -A \[ -L \] \[ `modalias`\[=`module`\] ... \]  
For each argument, if both `modalias` and `module` are given, define
`modalias` to be an alias for the module `module`. If the module
`modalias` is ever subsequently requested, either via a call to zmodload
or implicitly, the shell will attempt to load `module` instead. If
`module` is not given, show the definition of `modalias`. If no
arguments are given, list all defined module aliases. When listing, if
the -L flag was also given, list the definition as a zmodload command to
recreate the alias.

The existence of aliases for modules is completely independent of
whether the name resolved is actually loaded as a module: while the
alias exists, loading and unloading the module under any alias has
exactly the same effect as using the resolved name, and does not affect
the connection between the alias and the resolved name which can be
removed either by zmodload -R or by redefining the alias. Chains of
aliases (i.e. where the first resolved name is itself an alias) are
valid so long as these are not circular. As the aliases take the same
format as module names, they may include path separators: in this case,
there is no requirement for any part of the path named to exist as the
alias will be resolved first. For example, ‘any/old/alias’ is always a
valid alias.

Dependencies added to aliased modules are actually added to the resolved
module; these remain if the alias is removed. It is valid to create an
alias whose name is one of the standard shell modules and which resolves
to a different module. However, if a module has dependencies, it will
not be possible to use the module name as an alias as the module will
already be marked as a loadable module in its own right.

Apart from the above, aliases can be used in the zmodload command
anywhere module names are required. However, aliases will not be shown
in lists of loaded modules with a bare ‘zmodload’.

zmodload -R `modalias` ...  
For each `modalias` argument that was previously defined as a module
alias via zmodload -A, delete the alias. If any was not defined, an
error is caused and the remainder of the line is ignored.

Note that zsh makes no distinction between modules that were linked into
the shell and modules that are loaded dynamically. In both cases this
builtin command has to be used to make available the builtins and other
things defined by modules (unless the module is autoloaded on these
definitions). This is true even for systems that don’t support dynamic
loading of modules.

zparseopts

See [The zsh/zutil Module](Zsh-Modules.html#The-zsh_002fzutil-Module).

zprof

See [The zsh/zprof Module](Zsh-Modules.html#The-zsh_002fzprof-Module).

zpty

See [The zsh/zpty Module](Zsh-Modules.html#The-zsh_002fzpty-Module).

zregexparse

See [The zsh/zutil Module](Zsh-Modules.html#The-zsh_002fzutil-Module).

zsocket

See [The zsh/net/socket
Module](Zsh-Modules.html#The-zsh_002fnet_002fsocket-Module).

zstyle

See [The zsh/zutil Module](Zsh-Modules.html#The-zsh_002fzutil-Module).

ztcp

See [The zsh/net/tcp
Module](Zsh-Modules.html#The-zsh_002fnet_002ftcp-Module).

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

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.
