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. 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.

If the -s flags 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).

The flag -X may be used only inside a shell function, and may not be followed by a name. 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.

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.

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 in native or ksh emulation, 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.

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 -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.

See also the section `Precommand Modifiers'.

-c

clear the directory stack.

-l

print directory names in full instead of using of using ~ expressions.

-p

print directory entries one per line.

-v

number the directories in the stack when printing.

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.

\a

bell character

\b

backspace

\c

suppress 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.

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 zshmisc(1) .

If the -R option is given, all 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 option is given, the options LOCAL_OPTIONS and LOCAL_TRAPS will be set as well, causing the effects of the emulate command and any setopt 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 and -c are mutually exclusive.

If -c arg is given, evaluate arg while the requested emulation is temporarily in effect. The emulation and all options will be restored to their original values before emulate returns. The -R flag may be used.

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 flag, if present) and all options are set before entry to the function, and 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).

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. fni then calls fno; because fno 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 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 flag 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.

If the -l flag is given, the resulting commands are listed on standard output. If the -m flag is also given the first argument is taken as a pattern (should be quoted) and only the history events matching this pattern will be shown. Otherwise the editor program ename is invoked on a file containing these history events. If ename 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.

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.

The flag -r reverses the order of the commands and the flag -n suppresses command numbers when listing.

Also when listing,

-d

prints timestamps for each command

-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.

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 and at most max args. max may be -1 to indicate that there is no upper limit.

By default the function is implemented by a shell function of the same name; if shellfn is specified it gives the name of the corresponding shell function while mathfn remains the name used in arithmetical expressions. The name of the function in $0 is mathfn (not shellfn as would usually be the case), provided the option FUNCTION_ARGZERO is in effect. The positional parameters in the shell function correspond to the arguments of the mathematical function call. The result of the last arithmetical expression evaluated inside the shell function (even if it is a form that normally only returns a status) gives the result of the mathematical function.

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

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

For example, the following prints the cube of 3:

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

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 reset to 1 upon exit from a shell function. 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.

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.

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.

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.

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.

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.

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.

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

[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'.

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.

-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 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 directory names, replacing prefixes with ~ expressions, 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.

-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.

-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)).

-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.

-u n

Print the arguments to file descriptor n.

-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.

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 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.

-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. Currently does not work with the -q option.

-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; 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.

-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.

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.

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.

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

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.

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.

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.

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. Note that arrays currently cannot be assigned in typeset expressions, only scalars and integers. Unless the option KSH_TYPESET is set, normal expansion rules apply to assignment arguments, so value may be split into separate words; if the option is set, assignments which can be recognised when expansion is performed are treated as single words. For example the command typeset vbl=$(echo one two) is treated as having one argument if KSH_TYPESET is set, but otherwise is treated as having the two arguments vbl=one and two.

If the shell option TYPESET_SILENT is not set, for each remaining name that refers to a parameter that is 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 the -p option is given, parameters and values are printed in the form of a typeset command and an assignment (which will be printed separately for arrays and associative arrays), regardless of other flags and options. Note that the -h flag on parameters is respected; no value will be shown for these parameters.

If the -T option is given, two or three arguments must be present (an exception is that zero arguments are allowed to show the list of parameters created in this fashion). The first two are the name of a scalar and 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. Only the scalar parameter may be assigned an initial value. Both the scalar and the array may otherwise 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, or 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).

The -g (global) flag is treated specially: it 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).

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. Also, if the last option is the word `+', then names are printed but values are not.

If the -m flag is given the name arguments are taken as patterns (which should be quoted). 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). Note that -m is ignored if no patterns are given. 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 to be printed, even inside a function.

If no attribute flags are given and either no -m flag is present or the +m form was used, each parameter name printed is preceded by a list of the attributes of that parameter (array, association, exported, integer, readonly). 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.

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

Left justify and remove leading blanks from value. 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.

-R

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 colon-separated special parameters like PATH or FIGNORE, etc. This flag has a different meaning when used with -f; see below.

-Z

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 not be assigned to in the typeset statement. 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, -k, -u, -U and -z. The flag -t turns on execution tracing for this function. 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. The fpath parameter will be searched to find the function definition when the function is first referenced; see the section `Functions'. The -k and -z flags make the function be loaded using ksh-style or zsh-style autoloading respectively. If neither is given, the setting of the KSH_AUTOLOAD option determines how the function is loaded.

-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

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

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

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.

-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.

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.

-a

Lists all of the current resource limits.

-c

512-byte blocks on the size of core dumps.

-d

K-bytes on the size of the data segment.

-f

512-byte blocks on the size of files written.

-i

The number of pending signals.

-l

K-bytes on the size of locked-in memory.

-m

K-bytes on the size of physical memory.

-n

open file descriptors.

-q

Bytes in POSIX message queues.

-s

K-bytes on the size of the stack.

-t

CPU seconds to be used.

-u

processes available to the user.

-v

K-bytes on the size of virtual memory. On some systems this refers to the limit called `address space'.

-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.

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'.

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.

-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 (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.

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.

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.

-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).

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 [ -i ] 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. Hence `zmodload module 2>/dev/null' is sufficient to test whether a module is available. 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.

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.

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.

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.

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.

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.

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.