ZSHBUILTINS(1) User Commands ZSHBUILTINS(1)

NAME

zshbuiltins - zsh built-in commands

SHELL BUILTIN COMMANDS

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

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

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

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

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

- simple command
See the section `Precommand Modifiers' in zshmisc(1).

. 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.

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

alias [ {+|-}gmrsL ] [ name[=value] ... ]
For 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:

% 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

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,

alias -s ps='gv --'

will cause the command `*.ps' to be expanded to `gv -- *.ps'.
As alias expansion is carried out earlier than globbing, the
`*.ps' will then be expanded. Suffix aliases constitute a
different name space from other aliases (so in the above
example it is still possible to create an alias for the
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 alias in a manner
suitable for putting in a startup script. The exit 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 the section
ALIASING in zshmisc(1).

autoload [ {+|-}RTUXdkmrtWz ] [ -w ] [ name ... ]
See the section `Autoloading Functions' in zshmisc(1) 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 names 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:

emulate zsh -c 'autoload -Uz func'

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.

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

bindkey
See the section `Zle Builtins' in zshzle(1).

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.

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

bye Same as exit.

cap See the section `The zsh/cap Module' in zshmodules(1).

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 directory hash table.

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.

chdir Same as cd.

clone See the section `The zsh/clone Module' in zshmodules(1).

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 the section `Precommand Modifiers' in zshmisc(1).

comparguments
See the section `The zsh/computil Module' in zshmodules(1).

compcall
See the section `The zsh/compctl Module' in zshmodules(1).

compctl
See the section `The zsh/compctl Module' in zshmodules(1).

compdescribe
See the section `The zsh/computil Module' in zshmodules(1).

compfiles
See the section `The zsh/computil Module' in zshmodules(1).

compgroups
See the section `The zsh/computil Module' in zshmodules(1).

compquote
See the section `The zsh/computil Module' in zshmodules(1).

comptags
See the section `The zsh/computil Module' in zshmodules(1).

comptry
See the section `The zsh/computil Module' in zshmodules(1).

compvalues
See the section `The zsh/computil Module' in zshmodules(1).

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 nth
enclosing loop.

declare
Same as typeset.

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 (see Dynamic and Static named directories
in zshexpn(1)).

-p print directory entries one per line.

-v number the directories in the stack when printing.

disable [ -afmprs ] name ...
Temporarily disable the named hash table elements or patterns.
The default is to disable builtin commands. This allows you
to use an external command with the same name as a builtin
command. The -a option causes disable to act on regular or
global aliases. The -s option causes disable to act on suffix
aliases. The -f option causes disable to act on shell
functions. The -r options causes disable to act on reserved
words. Without arguments all disabled hash table elements
from the corresponding hash table are printed. With the -m
flag the arguments are taken as patterns (which should be
quoted to prevent them from undergoing filename expansion),
and all hash table elements from the corresponding hash table
matching these patterns are disabled. Disabled objects can be
enabled with the enable command.

With the option -p, name ... refer to elements of the shell's
pattern syntax as described in the section `Filename
Generation'. Certain elements can be disabled separately, as
given below.

Note that patterns not allowed by the current settings for the
options EXTENDED_GLOB, KSH_GLOB and SH_GLOB are never enabled,
regardless of the setting here. For example, if EXTENDED_GLOB
is not active, the pattern ^ is ineffective even if `disable
-p "^"' has not been issued. The list below indicates any
option settings that restrict the use of the pattern. It
should be noted that setting SH_GLOB has a wider effect than
merely disabling patterns as certain expressions, in
particular those involving parentheses, are parsed
differently.

The following patterns may be disabled; all the strings need
quoting on the command line to prevent them from being
interpreted immediately as patterns and the patterns are shown
below in single quotes as a reminder.

'?' 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 @(...).

disown [ job ... ]
job ... &|
job ... &!
Remove the specified jobs from the job table; the shell will
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 jobs 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 jobs will
automatically be made running, independent of the setting of
the AUTO_CONTINUE option.

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

\a bell character
\b backspace
\c suppress subsequent characters and final newline
\e escape
\f form feed
\n linefeed (newline)
\r carriage return
\t horizontal tab
\v vertical tab
\\ backslash
\0NNN character code in octal
\xNN character code in hexadecimal
\uNNNN unicode character code in hexadecimal
\UNNNNNNNN
unicode character code in hexadecimal

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

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

echotc See the section `The zsh/termcap Module' in zshmodules(1).

echoti See the section `The zsh/terminfo Module' in zshmodules(1).

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 the section COMPATIBILITY in zsh(1) . 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.

If the -R switch is given, all settable options 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
the section INVOCATION in zsh(1), except that `-o EMACS' and
`-o VI' may not be used. Flags such as `+r'/`+o RESTRICTED'
may be prohibited in some circumstances.

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

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

For example:

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

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

The documentation above is typically sufficient for the
intended purpose of executing code designed for other shells
in a suitable 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.

enable [ -afmprs ] name ...
Enable the named hash table elements, presumably disabled
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 all enabled hash table elements from
the corresponding hash table are printed. With the -m flag
the arguments are taken as patterns (should be quoted) and all
hash table elements from the corresponding hash table matching
these patterns are enabled. Enabled objects can be disabled
with the disable builtin command.

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

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

exec [ -cl ] [ -a argv0 ] [ command [ arg ... ] ]
Replace the current shell with command rather than forking.
If command is a shell builtin command or a shell function, the
shell executes it, and exits when the command is complete.

With -c clear the environment; with -l prepend - to the
argv[0] string of the command executed (to simulate a login
shell); with -a argv0 set the argv[0] string of the command
executed. See the section `Precommand Modifiers' in
zshmisc(1).

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

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

exit [ n ]
Exit the shell with the exit status specified by an arithmetic
expression n; if none is specified, use the exit status from
the last command executed. An EOF condition will also cause
the shell to exit, unless the IGNORE_EOF option is set.

See notes at the end of the section JOBS in zshmisc(1) for
some possibly unexpected interactions of the exit command with
jobs.

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

false [ arg ... ]
Do nothing and return an exit status of 1.


fc [ -e ename ] [ -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 zshoptions(1) -- 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 the section EXPANSION OF PROMPT SEQUENCES in
zshmisc(1). The resulting formatted string must be no
more than 256 characters or will not be printed
-D prints elapsed times; may be combined with one of the
options above

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

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

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

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

float [ {+|-}Hghlprtux ] [ {+|-}EFLRZ [ n ] ] [ name[=value] ... ]
Equivalent to typeset -E, except that options irrelevant to
floating point numbers are not permitted.

functions [ {+|-}UkmtTuWz ] [ -x num ] [ name ... ]
functions -c oldfn newfn
functions -M [-s] mathfn [ min [ max [ shellfn ] ] ]
functions -M [ -m pattern ... ]
functions +M [ -m ] mathfn ...
Equivalent to typeset -f, with the exception of the -c, -x, -M
and -W options. For functions -u and functions -U, see
autoload, which provides additional options. 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

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 the section `Arithmetic Evaluation' in
zshmisc(1). 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:

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

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):

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

Instead, the true builtin can be used:

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

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:

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

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 section `The zsh/cap Module' in zshmodules(1).

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

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

Each time it is invoked, getopts places the option letter it
finds in the shell parameter name, prepended with a `+' when
arg begins with a `+'. The index of the next arg is stored in
OPTIND. The option argument, if any, is stored in OPTARG.

The first option to be examined may be changed by explicitly
assigning to OPTIND. OPTIND has an initial value of 1, and is
normally set to 1 upon entry to a shell function and restored
upon exit. (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.

hash [ -Ldfmrv ] [ name[=value] ] ...
hash can be used to directly modify the contents of the
command hash table, and the named directory hash table.
Normally one would modify these tables by modifying one's PATH
(for the command hash table) or by creating appropriate shell
parameters (for the named directory hash table). The choice
of hash table to work on is determined by the -d option;
without the option the command hash table is used, and with
the option the named directory hash table is used.

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, the
selected hash table will be listed in full.

The -r option causes the selected hash table to be emptied.
It will be subsequently rebuilt in the normal fashion. The -f
option causes the selected hash table to be fully rebuilt
immediately. For the command hash table this hashes all the
absolute directories in the PATH, and for the named directory
hash table this adds all users' home directories. These two
options cannot be used with any arguments.

The -m option causes the arguments to be taken as patterns
(which should be quoted) and the elements of the hash table
matching those patterns are printed. This is the only way to
display a limited selection of hash table elements.

For each name with a corresponding value, put `name' in the
selected hash table, associating it with the pathname `value'.
In the command hash table, this means that whenever `name' is
used as a command argument, the shell will try to execute the
file given by `value'. In the named directory hash table,
this means that `value' may be referred to as `~name'.

For each name with no corresponding value, attempt to add name
to the hash table, checking what the appropriate value is in
the normal manner for that hash table. If an appropriate
value can't be found, then the hash table will be unchanged.

The -v option causes hash table entries to be listed as they
are added by explicit specification. If has no effect if used
with -f.

If the -L flag is present, then each hash table entry is
printed in the form of a call to hash.

history
Same as fc -l.

integer [ {+|-}Hghlprtux ] [ {+|-}LRZi [ n ] ] [ name[=value] ... ]
Equivalent to typeset -i, except that options irrelevant to
integers are not permitted.

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

The -Z option replaces the shell's argument and environment
space with the given string, truncated if necessary to fit.
This will normally be visible in ps (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,

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 &"
)

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

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

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

let arg ...
Evaluate each arg as an arithmetic expression. See the
section `Arithmetic Evaluation' in zshmisc(1) for a
description of arithmetic expressions. The exit status is 0
if the value of the last expression is nonzero, 1 if it is
zero, and 2 if an error occurred.

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

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

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

resource can be one of:

addressspace
Maximum amount of address space used.
aiomemorylocked
Maximum amount of memory locked in RAM for AIO
operations.
aiooperations
Maximum number of AIO operations.
cachedthreads
Maximum number of cached threads.
coredumpsize
Maximum size of a core dump.
cputime
Maximum CPU seconds per process.
datasize
Maximum data size (including stack) for each process.
descriptors
Maximum value for a file descriptor.
filesize
Largest single file allowed.
kqueues
Maximum number of kqueues allocated.
maxproc
Maximum number of processes.
maxpthreads
Maximum number of threads per process.
memorylocked
Maximum amount of memory locked in RAM.
memoryuse
Maximum resident set size.
msgqueue
Maximum number of bytes in POSIX message queues.
posixlocks
Maximum number of POSIX locks per user.
pseudoterminals
Maximum number of pseudo-terminals.
resident
Maximum resident set size.
sigpending
Maximum number of pending signals.
sockbufsize
Maximum size of all socket buffers.
stacksize
Maximum stack size for each process.
swapsize
Maximum amount of swap used.
vmemorysize
Maximum amount of virtual memory.

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

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

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

nh hours
nk kilobytes (default)
nm megabytes or minutes
ng gigabytes
[mm:]ss
minutes and seconds

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

local [ {+|-}AHUahlprtux ] [ {+|-}EFLRZi [ n ] ] [ name[=value] ... ]
Same as typeset, except that the options -g, and -f are not
permitted. In this case the -x option does not force the use
of -g, i.e. exported variables will be local to functions.

logout [ n ]
Same as exit, except that it only works in a login shell.

noglob simple command
See the section `Precommand Modifiers' in zshmisc(1).

popd [ -q ] [ {+|-}n ]
Remove an entry from the directory stack, and perform a cd to
the new top directory. With no argument, the current top
entry is removed. An argument of the form `+n' identifies a
stack entry by counting from the left of the list shown by the
dirs command, starting with zero. An argument of the form -n
counts from the right. If the PUSHD_MINUS option is set, the
meanings of `+' and `-' in this context are swapped.

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

print [ -abcDilmnNoOpPrsSz ] [ -u n ] [ -f format ] [ -C cols ]
[ -v name ] [ -xX tabstop ] [ -R [ -en ]] [ arg ... ]
With the `-f' option the arguments are printed as described by
printf. With no flags or with the flag `-', the arguments are
printed on the standard output as described by echo, with the
following differences: the escape sequence `\M-x' (or `\Mx')
metafies the character x (sets the highest bit), `\C-x' (or
`\Cx') produces a control character (`\C-@' and `\C-?' give
the characters NULL and delete), a character code in octal is
represented by `\NNN' (instead of `\0NNN'), 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 the section `Zle Builtins' in
zshzle(1).

-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 EXPANSION OF PROMPT
SEQUENCES in zshmisc(1)). 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 being used to produce a table
format.

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

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

printf [ -v name ] format [ arg ... ]
Print the arguments according to the format specification.
Formatting rules are the same as used in C. The same escape
sequences as for echo are recognised in the format. All C
conversion specifications ending in one of csdiouxXeEfgGn are
handled. In addition to this, `%b' can be used instead of `%s'
to cause escape sequences in the argument to be recognised and
`%q' can be used to quote the argument in such a way that
allows it to be reused as shell input. With the numeric format
specifiers, if the corresponding argument starts with a quote
character, the numeric value of the following character is
used as the number to print; otherwise the argument is
evaluated as an arithmetic expression. See the section
`Arithmetic Evaluation' in zshmisc(1) 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 nth
argument is to be used by replacing `%' by `%n$' and `*' by
`*n$'. It is recommended that you do not mix references of
this explicit style with the normal style and the handling of
such mixed styles may be subject to future change.

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

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

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

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

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

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

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

pushln [ arg ... ]
Equivalent to print -nz.

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

r Same as fc -e -.


read [ -rszpqAclneE ] [ -t [ num ] ] [ -k [ num ] ] [ -d delim ]
[ -u n ] [ [name][?prompt] ] [ name ... ]
Read one line and break it into fields using the characters in
$IFS as separators, except as noted below. The first field is
assigned to the first name, the second field to the second
name, etc., with leftover fields assigned to the last name.
If name is omitted then REPLY is used for scalars and reply
for arrays.

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

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

-q Read only one character from the terminal and 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 zshzle(1)). 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.

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

rehash Same as hash -r.

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

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

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

If return was executed from a trap in a TRAPNAL 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 section `The zsh/sched Module' in zshmodules(1).


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 zshoptions(1).
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 args; if no name is specified, all arrays
are printed together with their values.

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

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

set -A array -x -- foo

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

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

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

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

setcap See the section `The zsh/cap Module' in zshmodules(1).

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 zshoptions(1)). Options that are on by
default for the emulation are shown with the prefix no only if
they are off, while other options are shown without the prefix
no and only if they are on. In addition to options changed
from the default state by the user, any options activated
automatically by the shell (for example, SHIN_STDIN or
INTERACTIVE) will be shown in the list. The format is further
modified by the option KSH_OPTION_PRINT, however the rationale
for choosing options with or without the no prefix remains the
same in this case.

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

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

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

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

source file [ arg ... ]
Same as `.', except that the current directory is always
searched and is always searched first, before directories in
$path.

stat See the section `The zsh/stat Module' in zshmodules(1).

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

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

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

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

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

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

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

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

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

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

If sig is DEBUG then arg will be executed before each command
if the option DEBUG_BEFORE_CMD is set (as it is by default),
else after each command. Here, a `command' is what is
described as a `sublist' in the shell grammar, see the section
SIMPLE COMMANDS & PIPELINES in zshmisc(1). 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 zshoptions(1). 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 `TRAPNAL () { ... }', as the
latter have their own function environment (line numbers,
local variables, etc.) while the former use the environment of
the command in which they were called. For example,

trap 'print $LINENO' DEBUG

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

TRAPDEBUG() { print $LINENO; }

will always print the number zero.

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

true [ arg ... ]
Do nothing and return an exit status of 0.

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

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

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

type [ -wfpamsS ] name ...
Equivalent to whence -v.


typeset [ {+|-}AHUaghlmrtux ] [ {+|-}EFLRZip [ n ] ]
[ + ] [ name[=value] ... ]
typeset -T [ {+|-}Uglrux ] [ {+|-}LRZp [ n ] ]
[ + | SCALAR[=value] array[=(value ...)] [ sep ] ]
typeset -f [ {+|-}TUkmtuz ] [ + ] [ name ... ]
Set or display attributes and values for shell parameters.

Except as noted below for control flags that change the
behavior, a parameter is created for each name that does not
already refer to one. When inside a function, a new parameter
is created for every name (even those that already exist), and
is unset again when the function completes. See `Local
Parameters' in zshparam(1). 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:

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

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

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

On the other hand:

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

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

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

var='svar=val'
typeset $var

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

typeset {var1,var2,var3}=name

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

Note that each interface to any of the commands 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:

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

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


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

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

The following control flags change the behavior of typeset:

+ If `+' appears by itself in a separate word as the last
option, then the names of all parameters (functions
with -f) are printed, but the values (function bodies)
are not. 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' in zshparam(1).

-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 zshexpn(1).

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 Hide: only useful for special parameters (those marked
`<S>' in the table in zshparam(1)), and for local
parameters with the same name as a special parameter,
though harmless for others. A special parameter with
this attribute will not retain its special effect when
made local. Thus after `typeset -h PATH', a function
containing `typeset PATH' will create an ordinary local
parameter without the usual behaviour of PATH.
Alternatively, the local parameter may itself be given
this attribute; hence inside a function `typeset -h
PATH' creates an ordinary local parameter and the
special PATH parameter is not altered in any way. It
is also possible to create a local parameter using
`typeset +h special', where the local copy of special
will retain its special properties regardless of having
the -h attribute. Global special parameters loaded
from shell modules (currently those in zsh/mapfile and
zsh/parameter) are automatically given the -h attribute
to avoid name clashes.

-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 names 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.

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.

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.

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

unfunction
Same as unhash -f.

unhash [ -adfms ] name ...
Remove the element named name from an internal hash table.
The default is remove elements from the command hash table.
The -a 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 of the
corresponding hash table with matching names will be removed.

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

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

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

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

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

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

unset -f is equivalent to unfunction.

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

vared See the section `Zle Builtins' in zshzle(1).

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
of a job in the job table. The exit status from this command
is that of the job waited for. If job represents an unknown
job or process ID, a warning is printed (unless the
POSIX_BUILTINS option is set) and the exit status is 127.

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

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

whence [ -vcwfpamsS ] [ -x num ] name ...
For each name, indicate how it would be interpreted if used as
a command name.

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

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

-v Produce a more verbose report.

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

-w For 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.

where [ -wpmsS ] [ -x num ] name ...
Equivalent to whence -ca.

which [ -wpamsS ] [ -x num ] name ...
Equivalent to whence -c.

zcompile [ -U ] [ -z | -k ] [ -R | -M ] file [ name ... ]
zcompile -ca [ -m ] [ -R | -M ] file [ name ... ]
zcompile -t file [ name ... ]
This builtin command can be used to compile functions or
scripts, storing the compiled form in a file, and to examine
files containing the compiled form. This allows faster
autoloading of functions and sourcing of scripts by avoiding
parsing of the text when the files are read.

The first form (without the -c, -a or -t options) creates a
compiled file. If only the file argument is given, the output
file has the name `file.zwc' and will be placed in the same
directory as the file. The shell will load the compiled file
instead of the normal function file when the function is
autoloaded; see the section `Autoloading Functions' in
zshmisc(1) for a description of how autoloaded functions are
searched. The extension .zwc stands for `zsh word code'.

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

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

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

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

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

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

can be compiled but

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

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

The third form, with the -t option, examines an existing
compiled file. Without further arguments, the names of the
original files compiled into it are listed. The first line of
output shows the version of the shell which compiled the file
and how the file will be used (i.e. by reading it directly or
by mapping it into memory). With arguments, nothing is output
and the return status is set to zero if definitions for all
names 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 named
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 names 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 section `The zsh/zutil Module' in zshmodules(1).

zftp See the section `The zsh/zftp Module' in zshmodules(1).

zle See the section `Zle Builtins' in zshzle(1).

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 shell executable
without dynamical loading.

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 named 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 features is set to
the required state. If no features 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 builtins. 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 strings 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 section `The zsh/zutil Module' in zshmodules(1).

zprof See the section `The zsh/zprof Module' in zshmodules(1).

zpty See the section `The zsh/zpty Module' in zshmodules(1).

zregexparse
See the section `The zsh/zutil Module' in zshmodules(1).

zsocket
See the section `The zsh/net/socket Module' in zshmodules(1).

zstyle See the section `The zsh/zutil Module' in zshmodules(1).

ztcp See the section `The zsh/net/tcp Module' in zshmodules(1).

zsh 5.9 May 14, 2022 ZSHBUILTINS(1)