The return status of the builtin is zero in both shells if successful, and non-zero on error.

The target of clone should be an unused terminal, such as an unused virtual console or a virtual terminal created by

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

Some words of explanation are warranted about this long xterm command line: when doing clone on a pseudo-terminal, some other session ("session" meant as a unix session group, or SID) is already owning the terminal. Hence the cloned zsh cannot acquire the pseudo-terminal as a controlling tty. That means two things:

•

the job control signals will go to the sh-started-by-xterm process group (that's why we disable INT QUIT and TSTP with trap; otherwise the while loop could get suspended or killed)

•

the cloned shell will have job control disabled, and the job control keys (control-C, control-\ and control-Z) will not work.

This does not apply when cloning to an unused vc.

Cloning to a used (and unprepared) terminal will result in two processes reading simultaneously from the same terminal, with input bytes going randomly to either process.

clone is mostly useful as a shell built-in replacement for openvt.

Once compdescribe has been called with either the -i or the -I option, it can be repeatedly called with the -g option and the names of four parameters as its arguments. This will step through the different sets of matches and store the value of compstate[list] in the first scalar, the options for compadd in the second array, the matches in the third array, and the strings to be displayed in the completion listing in the fourth array. The arrays may then be directly given to compadd to register the matches with the completion code.

The return status is non-zero in case of an error and zero otherwise.

-n

Suppress printing a newline after the formatted string.

-q

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

-r

With the option -r (reverse), use format to parse the input string timestring and output the number of seconds since the epoch at which the time occurred. The parsing is implemented by the system function strptime; see strptime(3). This means that zsh format extensions are not available, but for reverse lookup they are not required.

-s scalar

Assign the date string (or epoch time in seconds if -r is given) to scalar instead of printing it.

Note that depending on the system's declared integral time type, strftime may produce incorrect results for epoch times greater than 2147483647 which corresponds to 2038-01-19 03:14:07 +0000.

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

The -r option opens the database file for reading only, creating a parameter with the readonly attribute. Without this option, using `ztie' on a file for which the user does not have write permission is an error. If writable, the database is opened synchronously so fields changed in arrayname are immediately written to filename.

Changes to the file modes filename after it has been opened do not alter the state of arrayname, but `typeset -r arrayname' works as expected.

This happens automatically if the parameter is explicitly unset or its local scope (function) ends. Note that a readonly parameter may not be explicitly unset, so the only way to unset a global parameter created with `ztie -r' is to use `zuntie -u'.

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

The specified mode must be in octal.

The -R option causes chmod to recursively descend into directories, changing the mode of all files in the directory after changing the mode of the directory itself.

The -s option is a zsh extension to chmod functionality. It enables paranoid behaviour, intended to avoid security problems involving a chmod being tricked into affecting files other than the ones intended. It will refuse to follow symbolic links, so that (for example) ``chmod 600 /tmp/foo/passwd'' can't accidentally chmod /etc/passwd if /tmp/foo happens to be a link to /etc. It will also check where it is after leaving directories, so that a recursive chmod of a deep directory tree can't end up recursively chmoding /usr as a result of directories being moved up the tree.

The user-spec can be in four forms:

user

change owner to user; do not change group

user::

change owner to user; do not change group

user:

change owner to user; change group to user's primary group

user:group

change owner to user; change group to group

:group

do not change owner; change group to group

In each case, the `:' may instead be a `.'. The rule is that if there is a `:' then the separator is `:', otherwise if there is a `.' then the separator is `.', otherwise there is no separator.

Each of user and group may be either a username (or group name, as appropriate) or a decimal user ID (group ID). Interpretation as a name takes precedence, if there is an all-numeric username (or group name).

If the target is a symbolic link, the -h option causes chown to set the ownership of the link instead of its target.

The -R option causes chown to recursively descend into directories, changing the ownership of all files in the directory after changing the ownership of the directory itself.

The -s option is a zsh extension to chown functionality. It enables paranoid behaviour, intended to avoid security problems involving a chown being tricked into affecting files other than the ones intended. It will refuse to follow symbolic links, so that (for example) ``chown luser /tmp/foo/passwd'' can't accidentally chown /etc/passwd if /tmp/foo happens to be a link to /etc. It will also check where it is after leaving directories, so that a recursive chown of a deep directory tree can't end up recursively chowning /usr as a result of directories being moved up the tree.

Normally, ln will not attempt to create hard links to directories. This check can be overridden using the -d option. Typically only the super-user can actually succeed in creating hard links to directories. This does not apply to symbolic links in any case.

By default, existing files cannot be replaced by links. The -i option causes the user to be queried about replacing existing files. The -f option causes existing files to be silently deleted, without querying. -f takes precedence.

The -h and -n options are identical and both exist for compatibility; either one indicates that if the target is a symlink then it should not be dereferenced. Typically this is used in combination with -sf so that if an existing link points to a directory then it will be removed, instead of followed. If this option is used with multiple filenames and the target is a symbolic link pointing to a directory then the result is an error.

By default, the user will be queried before replacing any file that the user cannot write to, but writable files will be silently removed. The -i option causes the user to be queried about replacing any existing files. The -f option causes any existing files to be silently deleted, without querying. -f takes precedence.

Note that this mv will not move files across devices. Historical versions of mv, when actual renaming is impossible, fall back on copying and removing files; if this behaviour is desired, use cp and rm manually. This may change in a future version.

Normally, rm will not remove directories (except with the -R or -r options). The -d option causes rm to try removing directories with unlink (see unlink(2)), the same method used for files. Typically only the super-user can actually succeed in unlinking directories in this way. -d takes precedence over -R and -r.

By default, the user will be queried before removing any file that the user cannot write to, but writable files will be silently removed. The -i option causes the user to be queried about removing any files. The -f option causes files to be silently deleted, without querying, and suppresses all error indications. -f takes precedence.

The -R and -r options cause rm to recursively descend into directories, deleting all files in the directory before removing the directory with the rmdir system call (see rmdir(2)).

The -s option is a zsh extension to rm functionality. It enables paranoid behaviour, intended to avoid common security problems involving a root-run rm being tricked into removing files other than the ones intended. It will refuse to follow symbolic links, so that (for example) ``rm /tmp/foo/passwd'' can't accidentally remove /etc/passwd if /tmp/foo happens to be a link to /etc. It will also check where it is after leaving directories, so that a recursive removal of a deep directory tree can't end up recursively removing /usr as a result of directories being moved up the tree.

Your implementation may support a number of the following keys:

CODESET, D_T_FMT, D_FMT, T_FMT, RADIXCHAR, THOUSEP, YESEXPR, NOEXPR, CRNCYSTR, ABDAY_{1..7}, DAY_{1..7}, ABMON_{1..12}, MON_{1..12}, T_FMT_AMPM, AM_STR, PM_STR, ERA, ERA_D_FMT, ERA_D_T_FMT, ERA_T_FMT, ALT_DIGITS

When the array is accessed as a whole, the keys are the names of files in the current directory, and the values are empty (to save a huge overhead in memory). Thus ${(k)mapfile} has the same effect as the glob operator *(D), since files beginning with a dot are not special. Care must be taken with expressions such as rm ${(k)mapfile}, which will delete every file in the current directory without the usual `rm *' test.

The parameter mapfile may be made read-only; in that case, files referenced may not be written or deleted.

A file may conveniently be read into an array as one line per element with the form `array=("${(f@)mapfile[filename]}")'. The double quotes and the `@' are necessary to prevent empty lines from being removed. Note that if the file ends with a newline, the shell will split on the final newline, generating an additional empty field; this can be suppressed by using `array=("${(f@)${mapfile[filename]%$'\n'}}")'.

(( f = sin(0.3) ))

print $(( rand48(seed) ))
print $(( rand48() ))
print $(( rand48(seed) ))

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

For an autoloaded function that has already been loaded, or marked for autoload with an absolute path, or that has had its path resolved with `functions -r', this is the file found for autoloading, resolved to an absolute path.

For a function defined within the body of a script or sourced file, this is the name of that file. In this case, this is the exact path originally used to that file, which may be a relative path.

For any other function, including any defined at an interactive prompt or an autoload function whose path has not yet been resolved, this is the empty string. However, the hash element is reported as defined just so long as the function is present: the keys to this hash are the same as those to $functions.

Setting or unsetting keys in this array is not possible.

The keys of the associative arrays are usually valid job numbers, and these are the values output with, for example, ${(k)jobdirs}. Non-numeric job references may be used when looking up a value; for example, ${jobdirs[%+]} refers to the current job.

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

Handling of the keys of the associative array is as described for jobdirs above.

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

Handling of the keys of the associative array is as described for jobdirs above.

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

For functions autoloaded from a file in native zsh format, where only the body of the function occurs in the file, or for files that have been executed by the source or `.' builtins, the trace information is shown as filename:0, since the entire file is the definition. The source file name is resolved to an absolute path when the function is loaded or the path to it otherwise resolved.

Most users will be interested in the information in the funcfiletrace array instead.

The standard shell array zsh_eval_context can be used to determine the type of shell construct being executed at each depth: note, however, that is in the opposite order, with the most recent item last, and it is more detailed, for example including an entry for toplevel, the main shell code being executed either interactively or from a script, which is not present in $funcstack.

Option -a will force the pattern to be anchored. Option -i will compile a case-insensitive pattern. Option -m will compile a multi-line pattern; that is, ^ and $ will match newlines within the pattern. Option -x will compile an extended pattern, wherein whitespace and # comments are ignored. Option -s makes the dot metacharacter match all characters, including those that indicate newline.

Upon successful match, if the expression captures substrings within parentheses, pcre_match will set the array match to those substrings, unless the -a option is given, in which case it will set the array arr. Similarly, the variable MATCH will be set to the entire matched portion of the string, unless the -v option is given, in which case the variable var will be set. No variables are altered if there is no successful match. A -n option starts searching for a match from the byte offset position in string. If the -b option is given, the variable ZPCRE_OP will be set to an offset pair string, representing the byte offset positions of the entire matched portion within the string. For example, a ZPCRE_OP set to "32 45" indicates that the matched portion began on byte offset 32 and ended on byte offset 44. Here, byte offset position 45 is the position directly after the matched portion. Keep in mind that the byte position isn't necessarily the same as the character position when UTF-8 characters are involved. Consequently, the byte offset positions are only to be relied on in the context of using them for subsequent searches on string, using an offset position as an argument to the -n option. This is mostly used to implement the "find all non-overlapping matches" functionality.

A simple example of "find all non-overlapping matches":

string="The following zip codes: 78884 90210 99513"
pcre_compile -m "\d{5}"
accum=()
pcre_match -b -- $string
while [[ $? -eq 0 ]] do
    b=($=ZPCRE_OP)
    accum+=$MATCH
    pcre_match -b -n $b[2] -- $string
done
print -l $accum

For example,

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

If the REMATCH_PCRE option is set, the =~ operator is equivalent to -pcre-match, and the NO_CASE_MATCH option may be used. Note that NO_CASE_MATCH never applies to the pcre_match builtin, instead use the -i switch of pcre_compile.

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

If used at the top level (outside a function scope), private creates a normal parameter in the same manner as declare or typeset. A warning about this is printed if WARN_CREATE_GLOBAL is set (zshoptions(1)). Used inside a function scope, private creates a local parameter similar to one declared with local, except having special properties noted below.

Special parameters which expose or manipulate internal shell state, such as ARGC, argv, COLUMNS, LINES, UID, EUID, IFS, PROMPT, RANDOM, SECONDS, etc., cannot be made private unless the `-h' option is used to hide the special meaning of the parameter. This may change in the future.

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

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

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

For example,

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

If the option REMATCH_PCRE is not set, then the =~ operator will automatically load this module as needed and will invoke the -regex-match operator.

If BASH_REMATCH is set, then the array BASH_REMATCH will be set instead of MATCH and match.

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

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

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

With no arguments, prints the list of scheduled commands. If the scheduled command has the -o flag set, this is shown at the start of the command.

With the argument `-item', removes the given item from the list. The numbering of the list is continuous and entries are in time order, so the numbering can change when entries are added or deleted.

Commands are executed either immediately before a prompt, or while the shell's line editor is waiting for input. In the latter case it is useful to be able to produce output that does not interfere with the line being edited. Providing the option -o causes the shell to clear the command line before the event and redraw it afterwards. This should be used with any scheduled event that produces visible output to the terminal; it is not needed, for example, with output that updates a terminal emulator's title bar.

To effect changes to the editor buffer when an event executes, use the `zle' command with no arguments to test whether the editor is active, and if it is, then use `zle widget' to access the editor via the named widget.

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

The sched builtin should be used for manipulating the events. Note that this will have an immediate effect on the contents of the array, so that indices may become invalid.

If the stat call fails, the appropriate system error message printed and status 1 is returned. The fields of struct stat give information about the files provided as arguments to the command. In addition to those available from the stat call, an extra element `link' is provided. These elements are:

device

The number of the device on which the file resides.

inode

The unique number of the file on this device (`inode' number).

mode

The mode of the file; that is, the file's type and access permissions. With the -s option, this will be returned as a string corresponding to the first column in the display of the ls -l command.

nlink

The number of hard links to the file.

uid

The user ID of the owner of the file. With the -s option, this is displayed as a user name.

gid

The group ID of the file. With the -s option, this is displayed as a group name.

rdev

The raw device number. This is only useful for special devices.

size

The size of the file in bytes.

atime

mtime

ctime

The last access, modification and inode change times of the file, respectively, as the number of seconds since midnight GMT on 1st January, 1970. With the -s option, these are printed as strings for the local time zone; the format can be altered with the -F option, and with the -g option the times are in GMT.

blksize

The number of bytes in one allocation block on the device on which the file resides.

block

The number of disk blocks used by the file.

link

If the file is a link and the -L option is in effect, this contains the name of the file linked to, otherwise it is empty. Note that if this element is selected (``zstat +link'') then the -L option is automatically used.

A particular element may be selected by including its name preceded by a `+' in the option list; only one element is allowed. The element may be shortened to any unique set of leading characters. Otherwise, all elements will be shown for all files.

Options:

-A array

Instead of displaying the results on standard output, assign them to an array, one struct stat element per array element for each file in order. In this case neither the name of the element nor the name of the files appears in array unless the -t or -n options were given, respectively. If -t is given, the element name appears as a prefix to the appropriate array element; if -n is given, the file name appears as a separate array element preceding all the others. Other formatting options are respected.

-H hash

Similar to -A, but instead assign the values to hash. The keys are the elements listed above. If the -n option is provided then the name of the file is included in the hash with key name.

-f fd

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

-F fmt

Supplies a strftime (see strftime(3)) string for the formatting of the time elements. The format string supports all of the zsh extensions described in the section EXPANSION OF PROMPT SEQUENCES in zshmisc(1). In particular, -F %s.%N can be used to show timestamps with nanosecond precision if supported by the system. The -s option is implied.

-g

Show the time elements in the GMT time zone. The -s option is implied.

-l

List the names of the type elements (to standard output or an array as appropriate) and return immediately; arguments, and options other than -A, are ignored.

-L

Perform an lstat (see lstat(2)) rather than a stat system call. In this case, if the file is a link, information about the link itself rather than the target file is returned. This option is required to make the link element useful. It's important to note that this is the exact opposite from ls(1), etc.

-n

Always show the names of files. Usually these are only shown when output is to standard output and there is more than one file in the list.

-N

Never show the names of files.

-o

If a raw file mode is printed, show it in octal, which is more useful for human consumption than the default of decimal. A leading zero will be printed in this case. Note that this does not affect whether a raw or formatted file mode is shown, which is controlled by the -r and -s options, nor whether a mode is shown at all.

-r

Print raw data (the default format) alongside string data (the -s format); the string data appears in parentheses after the raw data.

-s

Print mode, uid, gid and the three time elements as strings instead of numbers. In each case the format is like that of ls -l.

-t

Always show the type names for the elements of struct stat. Usually these are only shown when output is to standard output and no individual element has been selected.

-T

Never show the type names of the struct stat elements.

If ztcp is run with no options, it will output the contents of its session table.

If it is run with only the option -L, it will output the contents of the session table in a format suitable for automatic parsing. The option is ignored if given with a command to open or close a session. The output consists of a set of lines, one per session, each containing the following elements separated by spaces:

File descriptor

The file descriptor in use for the connection. For normal inbound (I) and outbound (O) connections this may be read and written by the usual shell mechanisms. However, it should only be close with `ztcp -c'.

Connection type

A letter indicating how the session was created:

The local host

This is usually set to an all-zero IP address as the address of the localhost is irrelevant.

The local port

This is likely to be zero unless the connection is for listening.

The remote host

This is the fully qualified domain name of the peer, if available, else an IP address. It is an all-zero IP address for a session opened for listening.

The remote port

This is zero for a connection opened for listening.

If it contains the single word `all', then all login/logout events are reported. If it contains the single word `notme', then all events are reported as with `all' except $USERNAME.

An entry in this list may consist of a username, an `@' followed by a remote hostname, and a `%' followed by a line (tty). Any of these may be a pattern (be sure to quote this during the assignment to watch so that it does not immediately perform file generation); the setting of the EXTENDED_GLOB option is respected. Any or all of these components may be present in an entry; if a login/logout event matches all of them, it is reported.

For example, with the EXTENDED_GLOB option set, the following:

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

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

%n

The name of the user that logged in/out.

%a

The observed action, i.e. "logged on" or "logged off".

%l

The line (tty) the user is logged in on.

%M

The full hostname of the remote host.

%m

The hostname up to the first `.'. If only the IP address is available or the utmp field contains the name of an X-windows display, the whole name is printed.

%F{color} (%f)

Start (stop) using a different foreground color.

%K{color} (%k)

Start (stop) using a different background color.

%S (%s)

Start (stop) standout mode.

%U (%u)

Start (stop) underline mode.

%B (%b)

Start (stop) boldface mode.

%t

%@

The time, in 12-hour, am/pm format.

%T

The time, in 24-hour format.

%w

The date in `day-dd' format.

%W

The date in `mm/dd/yy' format.

%D

The date in `yy-mm-dd' format.

%D{string}

The date formatted as string using the strftime function, with zsh extensions as described by EXPANSION OF PROMPT SEQUENCES in zshmisc(1).

%(x:true-text:false-text)

Specifies a ternary expression. The character following the x is arbitrary; the same character is used to separate the text for the "true" result from that for the "false" result. Both the separator and the right parenthesis may be escaped with a backslash. Ternary expressions may be nested.

All commands consist of the command name zftp followed by the name of a subcommand. These are listed below. The return status of each subcommand is supposed to reflect the success or failure of the remote operation. See a description of the variable ZFTP_VERBOSE for more information on how responses from the server may be printed.

At the top there is a summary listing all functions that were called at least once. This summary is sorted in decreasing order of the amount of time spent in each. The lines contain the number of the function in order, which is used in other parts of the list in suffixes of the form `[num]', then the number of calls made to the function. The next three columns list the time in milliseconds spent in the function and its descendants, the average time in milliseconds spent in the function and its descendants per call and the percentage of time spent in all shell functions used in this function and its descendants. The following three columns give the same information, but counting only the time spent in the function itself. The final column shows the name of the function.

After the summary, detailed information about every function that was invoked is listed, sorted in decreasing order of the amount of time spent in each function and its descendants. Each of these entries consists of descriptions for the functions that called the function described, the function itself, and the functions that were called from it. The description for the function itself has the same format as in the summary (and shows the same information). The other lines don't show the number of the function at the beginning and have their function named indented to make it easier to distinguish the line showing the function described in the section from the surrounding lines.

The information shown in this case is almost the same as in the summary, but only refers to the call hierarchy being displayed. For example, for a calling function the column showing the total running time lists the time spent in the described function and its descendants only for the times when it was called from that particular calling function. Likewise, for a called function, this columns lists the total time spent in the called function and its descendants only for the times when it was called from the function described.

Also in this case, the column showing the number of calls to a function also shows a slash and then the total number of invocations made to the called function.

As long as the zsh/zprof module is loaded, profiling will be done and multiple invocations of the zprof builtin command will show the times and numbers of calls since the module was loaded. With the -c option, the zprof builtin command will reset its internal counters and will not show the listing.

With the -e option, the pseudo-terminal is set up so that input characters are echoed.

With the -b option, input to and output from the pseudo-terminal are made non-blocking.

The shell parameter REPLY is set to the file descriptor assigned to the master side of the pseudo-terminal. This allows the terminal to be monitored with ZLE descriptor handlers (see zshzle(1)) or manipulated with sysread and syswrite (see THE ZSH/SYSTEM MODULE in zshmodules(1)). Warning: Use of sysread and syswrite is not recommended; use zpty -r and zpty -w unless you know exactly what you are doing.

If no string is provided, the standard input is copied to the pseudo-terminal; this may stop before copying the full input if the pseudo-terminal is non-blocking. The exact input is always copied: the -n option is not applied.

Note that the command under the pseudo-terminal sees this input as if it were typed, so beware when sending special tty driver characters such as word-erase, line-kill, and end-of-file.

When also given a param argument, at most one line is read and stored in the parameter named param. Less than a full line may be read if the pseudo-terminal is non-blocking. The return status is zero if at least one character is stored in param.

If a pattern is given as well, output is read until the whole string read matches the pattern, even in the non-blocking case. The return status is zero if the string read matches the pattern, or if the command has exited but at least one character could still be read. If the option -m is present, the return status is zero only if the pattern matches. As of this writing, a maximum of one megabyte of output can be consumed this way; if a full megabyte is read without matching the pattern, the return status is non-zero.

In all cases, the return status is non-zero if nothing could be read, and is 2 if this is because the command has finished.

If the -r option is combined with the -t option, zpty tests whether output is available before trying to read. If no output is available, zpty immediately returns the status 1. When used with a pattern, the behaviour on a failed poll is similar to when the command has exited: the return value is zero if at least one character could still be read even if the pattern failed to match.

Arguments and options may be intermingled in any order. Non-option arguments are file descriptors, which must be decimal integers. By default, file descriptors are to be tested for reading, i.e. zselect will return when data is available to be read from the file descriptor, or more precisely, when a read operation from the file descriptor will not block. After a -r, -w and -e, the given file descriptors are to be tested for reading, writing, or error conditions. These options and an arbitrary list of file descriptors may be given in any order.

(The presence of an `error condition' is not well defined in the documentation for many implementations of the select system call. According to recent versions of the POSIX specification, it is really an exception condition, of which the only standard example is out-of-band data received on a socket. So zsh users are unlikely to find the -e option useful.)

The option `-t timeout' specifies a timeout in hundredths of a second. This may be zero, in which case the file descriptors will simply be polled and zselect will return immediately. It is possible to call zselect with no file descriptors and a non-zero timeout for use as a finer-grained replacement for `sleep'; note, however, the return status is always 1 for a timeout.

The option `-a array' indicates that array should be set to indicate the file descriptor(s) which are ready. If the option is not given, the array reply will be used for this purpose. The array will contain a string similar to the arguments for zselect. For example,

zselect -t 0 -r 0 -w 1

might return immediately with status 0 and $reply containing `-r 0 -w 1' to show that both file descriptors are ready for the requested operations.

The option `-A assoc' indicates that the associative array assoc should be set to indicate the file descriptor(s) which are ready. This option overrides the option -a, nor will reply be modified. The keys of assoc are the file descriptors, and the corresponding values are any of the characters `rwe' to indicate the condition.

The command returns status 0 if some file descriptors are ready for reading. If the operation timed out, or a timeout of 0 was given and no file descriptors were ready, or there was an error, it returns status 1 and the array will not be set (nor modified in any way). If there was an error in the select operation the appropriate error message is printed.

A pattern is considered to be more specific than another if it contains more components (substrings separated by colons) or if the patterns for the components are more specific, where simple strings are considered to be more specific than patterns and complex patterns are considered to be more specific than the pattern `*'. A `*' in the pattern will match zero or more characters in the context; colons are not treated specially in this regard. If two patterns are equally specific, the tie is broken in favour of the pattern that was defined first.

Example

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

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

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

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

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

Usage

The forms that operate on patterns are the following.

zstyle [ -L [ metapattern [ style ] ] ]

Without arguments, lists style definitions. Styles are shown in alphabetic order and patterns are shown in the order zstyle will test them.

zstyle [ - | -- | -e ] pattern style string ...

Defines the given style for the pattern with the strings as the value. If the -e option is given, the strings will be concatenated (separated by spaces) and the resulting string will be evaluated (in the same way as it is done by the eval builtin command) when the style is looked up. In this case the parameter `reply' must be assigned to set the strings returned after the evaluation. Before evaluating the value, reply is unset, and if it is still unset after the evaluation, the style is treated as if it were not set.

zstyle -d [ pattern [ style ... ] ]

Delete style definitions. Without arguments all definitions are deleted, with a pattern all definitions for that pattern are deleted and if any styles are given, then only those styles are deleted for the pattern.

zstyle -g name [ pattern [ style ] ]

Retrieve a style definition. The name is used as the name of an array in which the results are stored. Without any further arguments, all patterns defined are returned. With a pattern the styles defined for that pattern are returned and with both a pattern and a style, the value strings of that combination is returned.

The other forms can be used to look up or test styles for a given context.

zstyle -s context style name [ sep ]

The parameter name is set to the value of the style interpreted as a string. If the value contains several strings they are concatenated with spaces (or with the sep string if that is given) between them.

zstyle -b context style name

The value is stored in name as a boolean, i.e. as the string `yes' if the value has only one string and that string is equal to one of `yes', `true', `on', or `1'. If the value is any other string or has more than one string, the parameter is set to `no'.

zstyle -a context style name

The value is stored in name as an array. If name is declared as an associative array, the first, third, etc. strings are used as the keys and the other strings are used as the values.

zstyle -t context style [ string ... ]

zstyle -T context style [ string ... ]

Test the value of a style, i.e. the -t option only returns a status (sets $?). Without any string the return status is zero if the style is defined for at least one matching pattern, has only one string in its value, and that is equal to one of `true', `yes', `on' or `1'. If any strings are given the status is zero if and only if at least one of the strings is equal to at least one of the strings in the value. If the style is defined but doesn't match, the return status is 1. If the style is not defined, the status is 2.

zstyle -m context style pattern

Match a value. Returns status zero if the pattern matches at least one of the strings in the value.

The %-escapes also understand ternary expressions in the form used by prompts. The % is followed by a `(' and then an ordinary format specifier character as described above. There may be a set of digits either before or after the `('; these specify a test number, which defaults to zero. Negative numbers are also allowed. An arbitrary delimiter character follows the format specifier, which is followed by a piece of `true' text, the delimiter character again, a piece of `false' text, and a closing parenthesis. The complete expression (without the digits) thus looks like `%(X.text1.text2)', except that the `.' character is arbitrary. The value given for the format specifier in the char:string expressions is evaluated as a mathematical expression, and compared with the test number. If they are the same, text1 is output, else text2 is output. A parenthesis may be escaped in text2 as %). Either of text1 or text2 may contain nested %-escapes.

For example:

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

outputs "The answer is 'yes'." to REPLY since the value for the format specifier c is 3, agreeing with the digit argument to the ternary expression.

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

The form, using the -a option, can be used for aligning strings. Here, the specs are of the form `left:right' where `left' and `right' are arbitrary strings. These strings are modified by replacing the colons by the sep string and padding the left strings with spaces to the right so that the sep strings in the result (and hence the right strings after them) are all aligned if the strings are printed below each other. All strings without a colon are left unchanged and all strings with an empty right string have the trailing colon removed. In both cases the lengths of the strings are not used to determine how the other strings are to be aligned. A colon in the left string can be escaped with a backslash. The resulting strings are stored in the array.

Note that it is an error to give any spec without an `=array' unless one of the -a or -A options is used.

Unless the -E option is given, parsing stops at the first string that isn't described by one of the specs. Even with -E, parsing always stops at a positional parameter equal to `-' or `--'. See also -F.

The opt description must be one of the following. Any of the special characters can appear in the option name provided it is preceded by a backslash.

name

name+

The name is the name of the option without the leading `-'. To specify a GNU-style long option, one of the usual two leading `-' must be included in name; for example, a `--file' option is represented by a name of `-file'.

name:

name:-

name::

If one or two colons are given, the option takes an argument; with one colon, the argument is mandatory and with two colons it is optional. The argument is appended to the array after the option itself.

In all cases, option-arguments must appear either immediately following the option in the same positional parameter or in the next one. Even an optional argument may appear in the next parameter, unless it begins with a `-'. There is no special handling of `=' as with GNU-style argument parsers; given the spec `-foo:', the positional parameter `--foo=bar' is parsed as `--foo' with an argument of `=bar'.

When the names of two options that take no arguments overlap, the longest one wins, so that parsing for the specs `-foo -foobar' (for example) is unambiguous. However, due to the aforementioned handling of option-arguments, ambiguities may arise when at least one overlapping spec takes an argument, as in `-foo: -foobar'. In that case, the last matching spec wins.

The options of zparseopts itself cannot be stacked because, for example, the stack `-DEK' is indistinguishable from a spec for the GNU-style long option `--DEK'. The options of zparseopts itself are:

-a array

As described above, this names the default array in which to store the recognised options.

-A assoc

If this is given, the options and their values are also put into an associative array with the option names as keys and the arguments (if any) as the values.

-D

If this option is given, all options found are removed from the positional parameters of the calling shell or shell function, up to but not including any not described by the specs. If the first such parameter is `-' or `--', it is removed as well. This is similar to using the shift builtin.

-E

This changes the parsing rules to not stop at the first string that isn't described by one of the specs. It can be used to test for or (if used together with -D) extract options and their arguments, ignoring all other options and arguments that may be in the positional parameters. As indicated above, parsing still stops at the first `-' or `--' not described by a spec, but it is not removed when used with -D.

-F

If this option is given, zparseopts immediately stops at the first option-like parameter not described by one of the specs, prints an error message, and returns status 1. Removal (-D) and extraction (-E) are not performed, and option arrays are not updated. This provides basic validation for the given options.

-K

With this option, the arrays specified with the -a option and with the `=array' forms are kept unchanged when none of the specs for them is used. Otherwise the entire array is replaced when any of the specs is used. Individual elements of associative arrays specified with the -A option are preserved by -K. This allows assignment of default values to arrays before calling zparseopts.

-M

This changes the assignment rules to implement a map among equivalent option names. If any spec uses the `=array' form, the string array is interpreted as the name of another spec, which is used to choose where to store the values. If no other spec is found, the values are stored as usual. This changes only the way the values are stored, not the way $* is parsed, so results may be unpredictable if the `name+' specifier is used inconsistently.

For example,

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

will have the effect of

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

The arguments from `baz' on will not be used.

As an example for the -E option, consider:

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

will have the effect of

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

I.e., the option -b and its arguments are taken from the positional parameters and put into the array bar.

The -M option can be used like this:

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

to have the effect of

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