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ZSHMODULES(1) General Commands Manual ZSHMODULES(1)

NAME
zshmodules - zsh loadable modules

DESCRIPTION
Some optional parts of zsh are in modules, separate from the core of
the shell. Each of these modules may be linked in to the shell at
build time, or can be dynamically linked while the shell is running if
the installation supports this feature. Modules are linked at runtime
with the zmodload command, see zshbuiltins(1).

The modules that are bundled with the zsh distribution are:

zsh/attr
Builtins for manipulating extended attributes (xattr).

zsh/cap
Builtins for manipulating POSIX.1e (POSIX.6) capability (privi-
lege) sets.

zsh/clone
A builtin that can clone a running shell onto another terminal.

zsh/compctl
The compctl builtin for controlling completion.

zsh/complete
The basic completion code.

zsh/complist
Completion listing extensions.

zsh/computil
A module with utility builtins needed for the shell function
based completion system.

zsh/curses
curses windowing commands

zsh/datetime
Some date/time commands and parameters.

zsh/db/gdbm
Builtins for managing associative array parameters tied to GDBM
databases.

zsh/deltochar
A ZLE function duplicating EMACS' zap-to-char.

zsh/example
An example of how to write a module.

zsh/files
Some basic file manipulation commands as builtins.

zsh/langinfo
Interface to locale information.

zsh/mapfile
Access to external files via a special associative array.

zsh/mathfunc
Standard scientific functions for use in mathematical evalua-
tions.

zsh/nearcolor
Map colours to the nearest colour in the available palette.

zsh/newuser
Arrange for files for new users to be installed.

zsh/parameter
Access to internal hash tables via special associative arrays.

zsh/pcre
Interface to the PCRE library.

zsh/param/private
Builtins for managing private-scoped parameters in function con-
text.

zsh/regex
Interface to the POSIX regex library.

zsh/sched
A builtin that provides a timed execution facility within the
shell.

zsh/net/socket
Manipulation of Unix domain sockets

zsh/stat
A builtin command interface to the stat system call.

zsh/system
A builtin interface to various low-level system features.

zsh/net/tcp
Manipulation of TCP sockets

zsh/termcap
Interface to the termcap database.

zsh/terminfo
Interface to the terminfo database.

zsh/zftp
A builtin FTP client.

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

zsh/zleparameter
Access to internals of the Zsh Line Editor via parameters.

zsh/zprof
A module allowing profiling for shell functions.

zsh/zpty
A builtin for starting a command in a pseudo-terminal.

zsh/zselect
Block and return when file descriptors are ready.

zsh/zutil
Some utility builtins, e.g. the one for supporting configuration
via styles.

THE ZSH/ATTR MODULE
The zsh/attr module is used for manipulating extended attributes. The
-h option causes all commands to operate on symbolic links instead of
their targets. The builtins in this module are:

zgetattr [ -h ] filename attribute [ parameter ]
Get the extended attribute attribute from the specified file-
name. If the optional argument parameter is given, the attribute
is set on that parameter instead of being printed to stdout.

zsetattr [ -h ] filename attribute value
Set the extended attribute attribute on the specified filename
to value.

zdelattr [ -h ] filename attribute
Remove the extended attribute attribute from the specified file-
name.

zlistattr [ -h ] filename [ parameter ]
List the extended attributes currently set on the specified
filename. If the optional argument parameter is given, the list
of attributes is set on that parameter instead of being printed
to stdout.

zgetattr and zlistattr allocate memory dynamically. If the attribute
or list of attributes grows between the allocation and the call to get
them, they return 2. On all other errors, 1 is returned. This allows
the calling function to check for this case and retry.

THE ZSH/CAP MODULE
The zsh/cap module is used for manipulating POSIX.1e (POSIX.6) capabil-
ity sets. If the operating system does not support this interface, the
builtins defined by this module will do nothing. The builtins in this
module are:

cap [ capabilities ]
Change the shell's process capability sets to the specified ca-
pabilities, otherwise display the shell's current capabilities.

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

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

THE ZSH/CLONE MODULE
The zsh/clone module makes available one builtin command:

clone tty
Creates a forked instance of the current shell, attached to the
specified tty. In the new shell, the PID, PPID and TTY special
parameters are changed appropriately. $! is set to zero in the
new shell, and to the new shell's PID in the original shell.

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

The target of clone should be an unused terminal, such as an un-
used 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 al-
ready owning the terminal. Hence the cloned zsh cannot acquire
the pseudo-terminal as a controlling tty. That means two things:

o 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)

o 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.

THE ZSH/COMPCTL MODULE
The zsh/compctl module makes available two builtin commands. compctl,
is the old, deprecated way to control completions for ZLE. See zshcom-
pctl(1). The other builtin command, compcall can be used in user-de-
fined completion widgets, see zshcompwid(1).

THE ZSH/COMPLETE MODULE
The zsh/complete module makes available several builtin commands which
can be used in user-defined completion widgets, see zshcompwid(1).

THE ZSH/COMPLIST MODULE
The zsh/complist module offers three extensions to completion listings:
the ability to highlight matches in such a list, the ability to scroll
through long lists and a different style of menu completion.

Colored completion listings
Whenever one of the parameters ZLS_COLORS or ZLS_COLOURS is set and the
zsh/complist module is loaded or linked into the shell, completion
lists will be colored. Note, however, that complist will not automati-
cally be loaded if it is not linked in: on systems with dynamic load-
ing, `zmodload zsh/complist' is required.

The parameters ZLS_COLORS and ZLS_COLOURS describe how matches are
highlighted. To turn on highlighting an empty value suffices, in which
case all the default values given below will be used. The format of
the value of these parameters is the same as used by the GNU version of
the ls command: a colon-separated list of specifications of the form
`name=value'. The name may be one of the following strings, most of
which specify file types for which the value will be used. The strings
and their default values are:

no 0 for normal text (i.e. when displaying something other than a
matched file)

fi 0 for regular files

di 32 for directories

ln 36 for symbolic links. If this has the special value target, sym-
bolic links are dereferenced and the target file used to deter-
mine the display format.

pi 31 for named pipes (FIFOs)

so 33 for sockets

bd 44;37
for block devices

cd 44;37
for character devices

or none
for a symlink to nonexistent file (default is the value defined
for ln)

mi none
for a non-existent file (default is the value defined for fi);
this code is currently not used

su 37;41
for files with setuid bit set

sg 30;43
for files with setgid bit set

tw 30;42
for world writable directories with sticky bit set

ow 34;43
for world writable directories without sticky bit set

sa none
for files with an associated suffix alias; this is only tested
after specific suffixes, as described below

st 37;44
for directories with sticky bit set but not world writable

ex 35 for executable files

lc \e[ for the left code (see below)

rc m for the right code

tc 0 for the character indicating the file type printed after file-
names if the LIST_TYPES option is set

sp 0 for the spaces printed after matches to align the next column

ec none
for the end code

Apart from these strings, the name may also be an asterisk (`*') fol-
lowed by any string. The value given for such a string will be used for
all files whose name ends with the string. The name may also be an
equals sign (`=') followed by a pattern; the EXTENDED_GLOB option will
be turned on for evaluation of the pattern. The value given for this
pattern will be used for all matches (not just filenames) whose display
string are matched by the pattern. Definitions for the form with the
leading equal sign take precedence over the values defined for file
types, which in turn take precedence over the form with the leading as-
terisk (file extensions).

The leading-equals form also allows different parts of the displayed
strings to be colored differently. For this, the pattern has to use
the `(#b)' globbing flag and pairs of parentheses surrounding the parts
of the strings that are to be colored differently. In this case the
value may consist of more than one color code separated by equal signs.
The first code will be used for all parts for which no explicit code is
specified and the following codes will be used for the parts matched by
the sub-patterns in parentheses. For example, the specification
`=(#b)(?)*(?)=0=3=7' will be used for all matches which are at least
two characters long and will use the code `3' for the first character,
`7' for the last character and `0' for the rest.

All three forms of name may be preceded by a pattern in parentheses.
If this is given, the value will be used only for matches in groups
whose names are matched by the pattern given in the parentheses. For
example, `(g*)m*=43' highlights all matches beginning with `m' in
groups whose names begin with `g' using the color code `43'. In case
of the `lc', `rc', and `ec' codes, the group pattern is ignored.

Note also that all patterns are tried in the order in which they appear
in the parameter value until the first one matches which is then used.
Patterns may be matched against completions, descriptions (possibly
with spaces appended for padding), or lines consisting of a completion
followed by a description. For consistent coloring it may be necessary
to use more than one pattern or a pattern with backreferences.

When printing a match, the code prints the value of lc, the value for
the file-type or the last matching specification with a `*', the value
of rc, the string to display for the match itself, and then the value
of ec if that is defined or the values of lc, no, and rc if ec is not
defined.

The default values are ISO 6429 (ANSI) compliant and can be used on
vt100 compatible terminals such as xterms. On monochrome terminals the
default values will have no visible effect. The colors function from
the contribution can be used to get associative arrays containing the
codes for ANSI terminals (see the section `Other Functions' in zshcon-
trib(1)). For example, after loading colors, one could use
`$color[red]' to get the code for foreground color red and
`$color[bg-green]' for the code for background color green.

If the completion system invoked by compinit is used, these parameters
should not be set directly because the system controls them itself.
Instead, the list-colors style should be used (see the section `Comple-
tion System Configuration' in zshcompsys(1)).

Scrolling in completion listings
To enable scrolling through a completion list, the LISTPROMPT parameter
must be set. Its value will be used as the prompt; if it is the empty
string, a default prompt will be used. The value may contain escapes
of the form `%x'. It supports the escapes `%B', `%b', `%S', `%s',
`%U', `%u', `%F', `%f', `%K', `%k' and `%{...%}' used also in shell
prompts as well as three pairs of additional sequences: a `%l' or `%L'
is replaced by the number of the last line shown and the total number
of lines in the form `number/total'; a `%m' or `%M' is replaced with
the number of the last match shown and the total number of matches; and
`%p' or `%P' is replaced with `Top', `Bottom' or the position of the
first line shown in percent of the total number of lines, respectively.
In each of these cases the form with the uppercase letter will be re-
placed with a string of fixed width, padded to the right with spaces,
while the lowercase form will not be padded.

If the parameter LISTPROMPT is set, the completion code will not ask if
the list should be shown. Instead it immediately starts displaying the
list, stopping after the first screenful, showing the prompt at the
bottom, waiting for a keypress after temporarily switching to the
listscroll keymap. Some of the zle functions have a special meaning
while scrolling lists:

send-break
stops listing discarding the key pressed

accept-line, down-history, down-line-or-history
down-line-or-search, vi-down-line-or-history
scrolls forward one line

complete-word, menu-complete, expand-or-complete
expand-or-complete-prefix, menu-complete-or-expand
scrolls forward one screenful

accept-search
stop listing but take no other action

Every other character stops listing and immediately processes the key
as usual. Any key that is not bound in the listscroll keymap or that
is bound to undefined-key is looked up in the keymap currently se-
lected.

As for the ZLS_COLORS and ZLS_COLOURS parameters, LISTPROMPT should not
be set directly when using the shell function based completion system.
Instead, the list-prompt style should be used.

Menu selection
The zsh/complist module also offers an alternative style of selecting
matches from a list, called menu selection, which can be used if the
shell is set up to return to the last prompt after showing a completion
list (see the ALWAYS_LAST_PROMPT option in zshoptions(1)).

Menu selection can be invoked directly by the widget menu-select de-
fined by this module. This is a standard ZLE widget that can be bound
to a key in the usual way as described in zshzle(1).

Alternatively, the parameter MENUSELECT can be set to an integer, which
gives the minimum number of matches that must be present before menu
selection is automatically turned on. This second method requires that
menu completion be started, either directly from a widget such as
menu-complete, or due to one of the options MENU_COMPLETE or AUTO_MENU
being set. If MENUSELECT is set, but is 0, 1 or empty, menu selection
will always be started during an ambiguous menu completion.

When using the completion system based on shell functions, the MENUSE-
LECT parameter should not be used (like the ZLS_COLORS and ZLS_COLOURS
parameters described above). Instead, the menu style should be used
with the select=... keyword.

After menu selection is started, the matches will be listed. If there
are more matches than fit on the screen, only the first screenful is
shown. The matches to insert into the command line can be selected
from this list. In the list one match is highlighted using the value
for ma from the ZLS_COLORS or ZLS_COLOURS parameter. The default value
for this is `7' which forces the selected match to be highlighted using
standout mode on a vt100-compatible terminal. If neither ZLS_COLORS
nor ZLS_COLOURS is set, the same terminal control sequence as for the
`%S' escape in prompts is used.

If there are more matches than fit on the screen and the parameter
MENUPROMPT is set, its value will be shown below the matches. It sup-
ports the same escape sequences as LISTPROMPT, but the number of the
match or line shown will be that of the one where the mark is placed.
If its value is the empty string, a default prompt will be used.

The MENUSCROLL parameter can be used to specify how the list is
scrolled. If the parameter is unset, this is done line by line, if it
is set to `0' (zero), the list will scroll half the number of lines of
the screen. If the value is positive, it gives the number of lines to
scroll and if it is negative, the list will be scrolled the number of
lines of the screen minus the (absolute) value.

As for the ZLS_COLORS, ZLS_COLOURS and LISTPROMPT parameters, neither
MENUPROMPT nor MENUSCROLL should be set directly when using the shell
function based completion system. Instead, the select-prompt and se-
lect-scroll styles should be used.

The completion code sometimes decides not to show all of the matches in
the list. These hidden matches are either matches for which the com-
pletion function which added them explicitly requested that they not
appear in the list (using the -n option of the compadd builtin command)
or they are matches which duplicate a string already in the list (be-
cause they differ only in things like prefixes or suffixes that are not
displayed). In the list used for menu selection, however, even these
matches are shown so that it is possible to select them. To highlight
such matches the hi and du capabilities in the ZLS_COLORS and
ZLS_COLOURS parameters are supported for hidden matches of the first
and second kind, respectively.

Selecting matches is done by moving the mark around using the zle move-
ment functions. When not all matches can be shown on the screen at the
same time, the list will scroll up and down when crossing the top or
bottom line. The following zle functions have special meaning during
menu selection. Note that the following always perform the same task
within the menu selection map and cannot be replaced by user defined
widgets, nor can the set of functions be extended:

accept-line, accept-search
accept the current match and leave menu selection (but do not
cause the command line to be accepted)

send-break
leaves menu selection and restores the previous contents of the
command line

redisplay, clear-screen
execute their normal function without leaving menu selection

accept-and-hold, accept-and-menu-complete
accept the currently inserted match and continue selection al-
lowing to select the next match to insert into the line

accept-and-infer-next-history
accepts the current match and then tries completion with menu
selection again; in the case of files this allows one to select
a directory and immediately attempt to complete files in it; if
there are no matches, a message is shown and one can use undo to
go back to completion on the previous level, every other key
leaves menu selection (including the other zle functions which
are otherwise special during menu selection)

undo removes matches inserted during the menu selection by one of the
three functions before

down-history, down-line-or-history
vi-down-line-or-history, down-line-or-search
moves the mark one line down

up-history, up-line-or-history
vi-up-line-or-history, up-line-or-search
moves the mark one line up

forward-char, vi-forward-char
moves the mark one column right

backward-char, vi-backward-char
moves the mark one column left

forward-word, vi-forward-word
vi-forward-word-end, emacs-forward-word
moves the mark one screenful down

backward-word, vi-backward-word, emacs-backward-word
moves the mark one screenful up

vi-forward-blank-word, vi-forward-blank-word-end
moves the mark to the first line of the next group of matches

vi-backward-blank-word
moves the mark to the last line of the previous group of matches

beginning-of-history
moves the mark to the first line

end-of-history
moves the mark to the last line

beginning-of-buffer-or-history, beginning-of-line
beginning-of-line-hist, vi-beginning-of-line
moves the mark to the leftmost column

end-of-buffer-or-history, end-of-line
end-of-line-hist, vi-end-of-line
moves the mark to the rightmost column

complete-word, menu-complete, expand-or-complete
expand-or-complete-prefix, menu-expand-or-complete
moves the mark to the next match

reverse-menu-complete
moves the mark to the previous match

vi-insert
this toggles between normal and interactive mode; in interactive
mode the keys bound to self-insert and self-insert-unmeta insert
into the command line as in normal editing mode but without
leaving menu selection; after each character completion is tried
again and the list changes to contain only the new matches; the
completion widgets make the longest unambiguous string be in-
serted in the command line and undo and backward-delete-char go
back to the previous set of matches

history-incremental-search-forward
history-incremental-search-backward
this starts incremental searches in the list of completions dis-
played; in this mode, accept-line only leaves incremental
search, going back to the normal menu selection mode

All movement functions wrap around at the edges; any other zle function
not listed leaves menu selection and executes that function. It is
possible to make widgets in the above list do the same by using the
form of the widget with a `.' in front. For example, the widget `.ac-
cept-line' has the effect of leaving menu selection and accepting the
entire command line.

During this selection the widget uses the keymap menuselect. Any key
that is not defined in this keymap or that is bound to undefined-key is
looked up in the keymap currently selected. This is used to ensure
that the most important keys used during selection (namely the cursor
keys, return, and TAB) have sensible defaults. However, keys in the
menuselect keymap can be modified directly using the bindkey builtin
command (see zshmodules(1)). For example, to make the return key leave
menu selection without accepting the match currently selected one could
call

bindkey -M menuselect '^M' send-break

after loading the zsh/complist module.

THE ZSH/COMPUTIL MODULE
The zsh/computil module adds several builtin commands that are used by
some of the completion functions in the completion system based on
shell functions (see zshcompsys(1) ). Except for compquote these
builtin commands are very specialised and thus not very interesting
when writing your own completion functions. In summary, these builtin
commands are:

comparguments
This is used by the _arguments function to do the argument and
command line parsing. Like compdescribe it has an option -i to
do the parsing and initialize some internal state and various
options to access the state information to decide what should be
completed.

compdescribe
This is used by the _describe function to build the displays for
the matches and to get the strings to add as matches with their
options. On the first call one of the options -i or -I should
be supplied as the first argument. In the first case, display
strings without the descriptions will be generated, in the sec-
ond case, the string used to separate the matches from their de-
scriptions must be given as the second argument and the descrip-
tions (if any) will be shown. All other arguments are like the
definition arguments to _describe itself.

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

compfiles
Used by the _path_files function to optimize complex recursive
filename generation (globbing). It does three things. With the
-p and -P options it builds the glob patterns to use, including
the paths already handled and trying to optimize the patterns
with respect to the prefix and suffix from the line and the
match specification currently used. The -i option does the di-
rectory tests for the ignore-parents style and the -r option
tests if a component for some of the matches are equal to the
string on the line and removes all other matches if that is
true.

compgroups
Used by the _tags function to implement the internals of the
group-order style. This only takes its arguments as names of
completion groups and creates the groups for it (all six types:
sorted and unsorted, both without removing duplicates, with re-
moving all duplicates and with removing consecutive duplicates).

compquote [ -p ] names ...
There may be reasons to write completion functions that have to
add the matches using the -Q option to compadd and perform quot-
ing themselves. Instead of interpreting the first character of
the all_quotes key of the compstate special association and us-
ing the q flag for parameter expansions, one can use this
builtin command. The arguments are the names of scalar or array
parameters and the values of these parameters are quoted as
needed for the innermost quoting level. If the -p option is
given, quoting is done as if there is some prefix before the
values of the parameters, so that a leading equal sign will not
be quoted.

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

comptags
comptry
These implement the internals of the tags mechanism.

compvalues
Like comparguments, but for the _values function.

THE ZSH/CURSES MODULE
The zsh/curses module makes available one builtin command and various
parameters.

Builtin
zcurses init
zcurses end
zcurses addwin targetwin nlines ncols begin_y begin_x [ parentwin ]
zcurses delwin targetwin
zcurses refresh [ targetwin ... ]
zcurses touch targetwin ...
zcurses move targetwin new_y new_x
zcurses clear targetwin [ redraw | eol | bot ]
zcurses position targetwin array
zcurses char targetwin character
zcurses string targetwin string
zcurses border targetwin border
zcurses attr targetwin [ [+|-]attribute | fg_col/bg_col ] [...]
zcurses bg targetwin [ [+|-]attribute | fg_col/bg_col | @char ] [...]
zcurses scroll targetwin [ on | off | [+|-]lines ]
zcurses input targetwin [ param [ kparam [ mparam ] ] ]
zcurses mouse [ delay num | [+|-]motion ]
zcurses timeout targetwin intval
zcurses querychar targetwin [ param ]
zcurses resize height width [ endwin | nosave | endwin_nosave ]
Manipulate curses windows. All uses of this command should be
bracketed by `zcurses init' to initialise use of curses, and
`zcurses end' to end it; omitting `zcurses end' can cause the
terminal to be in an unwanted state.

The subcommand addwin creates a window with nlines lines and
ncols columns. Its upper left corner will be placed at row be-
gin_y and column begin_x of the screen. targetwin is a string
and refers to the name of a window that is not currently as-
signed. Note in particular the curses convention that vertical
values appear before horizontal values.

If addwin is given an existing window as the final argument, the
new window is created as a subwindow of parentwin. This differs
from an ordinary new window in that the memory of the window
contents is shared with the parent's memory. Subwindows must be
deleted before their parent. Note that the coordinates of sub-
windows are relative to the screen, not the parent, as with
other windows.

Use the subcommand delwin to delete a window created with ad-
dwin. Note that end does not implicitly delete windows, and
that delwin does not erase the screen image of the window.

The window corresponding to the full visible screen is called
stdscr; it always exists after `zcurses init' and cannot be
delete with delwin.

The subcommand refresh will refresh window targetwin; this is
necessary to make any pending changes (such as characters you
have prepared for output with char) visible on the screen. re-
fresh without an argument causes the screen to be cleared and
redrawn. If multiple windows are given, the screen is updated
once at the end.

The subcommand touch marks the targetwins listed as changed.
This is necessary before refreshing windows if a window that was
in front of another window (which may be stdscr) is deleted.

The subcommand move moves the cursor position in targetwin to
new coordinates new_y and new_x. Note that the subcommand
string (but not the subcommand char) advances the cursor posi-
tion over the characters added.

The subcommand clear erases the contents of targetwin. One (and
no more than one) of three options may be specified. With the
option redraw, in addition the next refresh of targetwin will
cause the screen to be cleared and repainted. With the option
eol, targetwin is only cleared to the end of the current cursor
line. With the option bot, targetwin is cleared to the end of
the window, i.e everything to the right and below the cursor is
cleared.

The subcommand position writes various positions associated with
targetwin into the array named array. These are, in order:
- The y and x coordinates of the cursor relative to the top
left of targetwin
- The y and x coordinates of the top left of targetwin on
the screen
- The size of targetwin in y and x dimensions.

Outputting characters and strings are achieved by char and
string respectively.

To draw a border around window targetwin, use border. Note that
the border is not subsequently handled specially: in other
words, the border is simply a set of characters output at the
edge of the window. Hence it can be overwritten, can scroll off
the window, etc.

The subcommand attr will set targetwin's attributes or fore-
ground/background color pair for any successive character out-
put. Each attribute given on the line may be prepended by a +
to set or a - to unset that attribute; + is assumed if absent.
The attributes supported are blink, bold, dim, reverse, stand-
out, and underline.

Each fg_col/bg_col attribute (to be read as `fg_col on bg_col')
sets the foreground and background color for character output.
The color default is sometimes available (in particular if the
library is ncurses), specifying the foreground or background
color with which the terminal started. The color pair de-
fault/default is always available. To use more than the 8 named
colors (red, green, etc.) construct the fg_col/bg_col pairs
where fg_col and bg_col are decimal integers, e.g 128/200. The
maximum color value is 254 if the terminal supports 256 colors.

bg overrides the color and other attributes of all characters in
the window. Its usual use is to set the background initially,
but it will overwrite the attributes of any characters at the
time when it is called. In addition to the arguments allowed
with attr, an argument @char specifies a character to be shown
in otherwise blank areas of the window. Owing to limitations of
curses this cannot be a multibyte character (use of ASCII char-
acters only is recommended). As the specified set of attributes
override the existing background, turning attributes off in the
arguments is not useful, though this does not cause an error.

The subcommand scroll can be used with on or off to enabled or
disable scrolling of a window when the cursor would otherwise
move below the window due to typing or output. It can also be
used with a positive or negative integer to scroll the window up
or down the given number of lines without changing the current
cursor position (which therefore appears to move in the opposite
direction relative to the window). In the second case, if
scrolling is off it is temporarily turned on to allow the window
to be scrolled.

The subcommand input reads a single character from the window
without echoing it back. If param is supplied the character is
assigned to the parameter param, else it is assigned to the pa-
rameter REPLY.

If both param and kparam are supplied, the key is read in `key-
pad' mode. In this mode special keys such as function keys and
arrow keys return the name of the key in the parameter kparam.
The key names are the macros defined in the curses.h or
ncurses.h with the prefix `KEY_' removed; see also the descrip-
tion of the parameter zcurses_keycodes below. Other keys cause
a value to be set in param as before. On a successful return
only one of param or kparam contains a non-empty string; the
other is set to an empty string.

If mparam is also supplied, input attempts to handle mouse in-
put. This is only available with the ncurses library; mouse
handling can be detected by checking for the exit status of
`zcurses mouse' with no arguments. If a mouse button is clicked
(or double- or triple-clicked, or pressed or released with a
configurable delay from being clicked) then kparam is set to the
string MOUSE, and mparam is set to an array consisting of the
following elements:
- An identifier to discriminate different input devices;
this is only rarely useful.
- The x, y and z coordinates of the mouse click relative to
the full screen, as three elements in that order (i.e.
the y coordinate is, unusually, after the x coordinate).
The z coordinate is only available for a few unusual in-
put devices and is otherwise set to zero.
- Any events that occurred as separate items; usually there
will be just one. An event consists of PRESSED, RE-
LEASED, CLICKED, DOUBLE_CLICKED or TRIPLE_CLICKED fol-
lowed immediately (in the same element) by the number of
the button.
- If the shift key was pressed, the string SHIFT.
- If the control key was pressed, the string CTRL.
- If the alt key was pressed, the string ALT.

Not all mouse events may be passed through to the terminal win-
dow; most terminal emulators handle some mouse events them-
selves. Note that the ncurses manual implies that using input
both with and without mouse handling may cause the mouse cursor
to appear and disappear.

The subcommand mouse can be used to configure the use of the
mouse. There is no window argument; mouse options are global.
`zcurses mouse' with no arguments returns status 0 if mouse han-
dling is possible, else status 1. Otherwise, the possible argu-
ments (which may be combined on the same command line) are as
follows. delay num sets the maximum delay in milliseconds be-
tween press and release events to be considered as a click; the
value 0 disables click resolution, and the default is one sixth
of a second. motion proceeded by an optional `+' (the default)
or - turns on or off reporting of mouse motion in addition to
clicks, presses and releases, which are always reported. How-
ever, it appears reports for mouse motion are not currently im-
plemented.

The subcommand timeout specifies a timeout value for input from
targetwin. If intval is negative, `zcurses input' waits indefi-
nitely for a character to be typed; this is the default. If
intval is zero, `zcurses input' returns immediately; if there is
typeahead it is returned, else no input is done and status 1 is
returned. If intval is positive, `zcurses input' waits intval
milliseconds for input and if there is none at the end of that
period returns status 1.

The subcommand querychar queries the character at the current
cursor position. The return values are stored in the array
named param if supplied, else in the array reply. The first
value is the character (which may be a multibyte character if
the system supports them); the second is the color pair in the
usual fg_col/bg_col notation, or 0 if color is not supported.
Any attributes other than color that apply to the character, as
set with the subcommand attr, appear as additional elements.

The subcommand resize resizes stdscr and all windows to given
dimensions (windows that stick out from the new dimensions are
resized down). The underlying curses extension (resize_term
call) can be unavailable. To verify, zeroes can be used for
height and width. If the result of the subcommand is 0, re-
size_term is available (2 otherwise). Tests show that resizing
can be normally accomplished by calling zcurses end and zcurses
refresh. The resize subcommand is provided for versatility. Mul-
tiple system configurations have been checked and zcurses end
and zcurses refresh are still needed for correct terminal state
after resize. To invoke them with resize, use endwin argument.
Using nosave argument will cause new terminal state to not be
saved internally by zcurses. This is also provided for versatil-
ity and should normally be not needed.

Parameters
ZCURSES_COLORS
Readonly integer. The maximum number of colors the terminal
supports. This value is initialised by the curses library and
is not available until the first time zcurses init is run.

ZCURSES_COLOR_PAIRS
Readonly integer. The maximum number of color pairs
fg_col/bg_col that may be defined in `zcurses attr' commands;
note this limit applies to all color pairs that have been used
whether or not they are currently active. This value is ini-
tialised by the curses library and is not available until the
first time zcurses init is run.

zcurses_attrs
Readonly array. The attributes supported by zsh/curses; avail-
able as soon as the module is loaded.

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

zcurses_keycodes
Readonly array. The values that may be returned in the second
parameter supplied to `zcurses input' in the order in which they
are defined internally by curses. Not all function keys are
listed, only F0; curses reserves space for F0 up to F63.

zcurses_windows
Readonly array. The current list of windows, i.e. all windows
that have been created with `zcurses addwin' and not removed
with `zcurses delwin'.

THE ZSH/DATETIME MODULE
The zsh/datetime module makes available one builtin command:

strftime [ -s scalar ] format [ epochtime [ nanoseconds ] ]
strftime -r [ -q ] [ -s scalar ] format timestring
Output the date in the format specified. With no epochtime, the
current system date/time is used; optionally, epochtime may be
used to specify the number of seconds since the epoch, and
nanoseconds may additionally be used to specify the number of
nanoseconds past the second (otherwise that number is assumed to
be 0). See strftime(3) for details. The zsh extensions de-
scribed in the section EXPANSION OF PROMPT SEQUENCES in zsh-
misc(1) are also available.

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

-r With the option -r (reverse), use format to parse the in-
put 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 strp-
time(3). This means that zsh format extensions are not
available, but for reverse lookup they are not required.

In most implementations of strftime any timezone in the
timestring is ignored and the local timezone declared by
the TZ environment variable is used; other parameters are
set to zero if not present.

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

If either of the system functions strptime or mktime is
not available, status 2 is returned and an error message
is printed.

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

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

The zsh/datetime module makes available several parameters; all are
readonly:

EPOCHREALTIME
A floating point value representing the number of seconds since
the epoch. The notional accuracy is to nanoseconds if the
clock_gettime call is available and to microseconds otherwise,
but in practice the range of double precision floating point and
shell scheduling latencies may be significant effects.

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

epochtime
An array value containing the number of seconds since the epoch
in the first element and the remainder of the time since the
epoch in nanoseconds in the second element. To ensure the two
elements are consistent the array should be copied or otherwise
referenced as a single substitution before the values are used.
The following idiom may be used:

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

THE ZSH/DB/GDBM MODULE
The zsh/db/gdbm module is used to create "tied" associative arrays that
interface to database files. If the GDBM interface is not available,
the builtins defined by this module will report an error. This module
is also intended as a prototype for creating additional database inter-
faces, so the ztie builtin may move to a more generic module in the fu-
ture.

The builtins in this module are:

ztie -d db/gdbm -f filename [ -r ] arrayname
Open the GDBM database identified by filename and, if success-
ful, create the associative array arrayname linked to the file.
To create a local tied array, the parameter must first be de-
clared, so commands similar to the following would be executed
inside a function scope:

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.

zuntie [ -u ] arrayname ...
Close the GDBM database associated with each arrayname and then
unset the parameter. The -u option forces an unset of parame-
ters made readonly with `ztie -r'.

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

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

zgdbm_tied
Array holding names of all tied parameters.

The fields of an associative array tied to GDBM are neither cached nor
otherwise stored in memory, they are read from or written to the data-
base on each reference. Thus, for example, the values in a readonly
array may be changed by a second writer of the same database file.

THE ZSH/DELTOCHAR MODULE
The zsh/deltochar module makes available two ZLE functions:

delete-to-char
Read a character from the keyboard, and delete from the cursor
position up to and including the next (or, with repeat count n,
the nth) instance of that character. Negative repeat counts
mean delete backwards.

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

THE ZSH/EXAMPLE MODULE
The zsh/example module makes available one builtin command:

example [ -flags ] [ args ... ]
Displays the flags and arguments it is invoked with.

The purpose of the module is to serve as an example of how to write a
module.

THE ZSH/FILES MODULE
The zsh/files module makes available some common commands for file ma-
nipulation as builtins; these commands are probably not needed for many
normal situations but can be useful in emergency recovery situations
with constrained resources. The commands do not implement all features
now required by relevant standards committees.

For all commands, a variant beginning zf_ is also available and loaded
automatically. Using the features capability of zmodload will let you
load only those names you want. Note that it's possible to load only
the builtins with zsh-specific names using the following command:

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

The commands loaded by default are:

chgrp [ -hRs ] group filename ...
Changes group of files specified. This is equivalent to chown
with a user-spec argument of `:group'.

chmod [ -Rs ] mode filename ...
Changes mode of files specified.

The specified mode must be in octal.

The -R option causes chmod to recursively descend into directo-
ries, 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 en-
ables 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 acciden-
tally 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.

chown [ -hRs ] user-spec filename ...
Changes ownership and group of files specified.

The user-spec can be in four forms:

user change owner to user; do not change group
user:: change owner to user; do not change group
user: change owner to user; change group to user's primary
group
user:group
change owner to user; change group to group
:group do not change owner; change group to group

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

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 directo-
ries, 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 en-
ables 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 acci-
dentally 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.

ln [ -dfhins ] filename dest
ln [ -dfhins ] filename ... dir
Creates hard (or, with -s, symbolic) links. In the first form,
the specified destination is created, as a link to the specified
filename. In the second form, each of the filenames is taken in
turn, and linked to a pathname in the specified directory that
has the same last pathname component.

Normally, ln will not attempt to create hard links to directo-
ries. This check can be overridden using the -d option. Typi-
cally 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 compati-
bility; 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 di-
rectory then it will be removed, instead of followed. If this
option is used with multiple filenames and the target is a sym-
bolic link pointing to a directory then the result is an error.

mkdir [ -p ] [ -m mode ] dir ...
Creates directories. With the -p option, non-existing parent
directories are first created if necessary, and there will be no
complaint if the directory already exists. The -m option can be
used to specify (in octal) a set of file permissions for the
created directories, otherwise mode 777 modified by the current
umask (see umask(2)) is used.

mv [ -fi ] filename dest
mv [ -fi ] filename ... dir
Moves files. In the first form, the specified filename is moved
to the specified destination. In the second form, each of the
filenames is taken in turn, and moved to a pathname in the spec-
ified directory that has the same last pathname component.

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. Histori-
cal versions of mv, when actual renaming is impossible, fall
back on copying and removing files; if this behaviour is de-
sired, use cp and rm manually. This may change in a future ver-
sion.

rm [ -dfiRrs ] filename ...
Removes files and directories specified.

Normally, rm will not remove directories (except with the -R or
-r options). The -d option causes rm to try removing directo-
ries 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 in-
dications. -f takes precedence.

The -R and -r options cause rm to recursively descend into di-
rectories, 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 en-
ables 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 di-
rectories being moved up the tree.

rmdir dir ...
Removes empty directories specified.

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

THE ZSH/LANGINFO MODULE
The zsh/langinfo module makes available one parameter:

langinfo
An associative array that maps langinfo elements to their val-
ues.

Your implementation may support a number of the following keys:

CODESET, D_T_FMT, D_FMT, T_FMT, RADIXCHAR, THOUSEP, YESEXPR, NO-
EXPR, 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

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

mapfile
This associative array takes as keys the names of files; the re-
sulting value is the content of the file. The value is treated
identically to any other text coming from a parameter. The
value may also be assigned to, in which case the file in ques-
tion is written (whether or not it originally existed); or an
element may be unset, which will delete the file in question.
For example, `vared mapfile[myfile]' works as expected, editing
the file `myfile'.

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

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

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

Limitations
Although reading and writing of the file in question is efficiently
handled, zsh's internal memory management may be arbitrarily baroque;
however, mapfile is usually very much more efficient than anything in-
volving a loop. Note in particular that the whole contents of the file
will always reside physically in memory when accessed (possibly multi-
ple times, due to standard parameter substitution operations). In par-
ticular, this means handling of sufficiently long files (greater than
the machine's swap space, or than the range of the pointer type) will
be incorrect.

No errors are printed or flagged for non-existent, unreadable, or un-
writable files, as the parameter mechanism is too low in the shell exe-
cution hierarchy to make this convenient.

It is unfortunate that the mechanism for loading modules does not yet
allow the user to specify the name of the shell parameter to be given
the special behaviour.

THE ZSH/MATHFUNC MODULE
The zsh/mathfunc module provides standard mathematical functions for
use when evaluating mathematical formulae. The syntax agrees with nor-
mal C and FORTRAN conventions, for example,

(( f = sin(0.3) ))

assigns the sine of 0.3 to the parameter f.

Most functions take floating point arguments and return a floating
point value. However, any necessary conversions from or to integer
type will be performed automatically by the shell. Apart from atan
with a second argument and the abs, int and float functions, all func-
tions behave as noted in the manual page for the corresponding C func-
tion, except that any arguments out of range for the function in ques-
tion will be detected by the shell and an error reported.

The following functions take a single floating point argument: acos,
acosh, asin, asinh, atan, atanh, cbrt, ceil, cos, cosh, erf, erfc, exp,
expm1, fabs, floor, gamma, j0, j1, lgamma, log, log10, log1p, log2,
logb, sin, sinh, sqrt, tan, tanh, y0, y1. The atan function can op-
tionally take a second argument, in which case it behaves like the C
function atan2. The ilogb function takes a single floating point argu-
ment, but returns an integer.

The function signgam takes no arguments, and returns an integer, which
is the C variable of the same name, as described in gamma(3). Note
that it is therefore only useful immediately after a call to gamma or
lgamma. Note also that `signgam()' and `signgam' are distinct expres-
sions.

The functions min, max, and sum are defined not in this module but in
the zmathfunc autoloadable function, described in the section `Mathe-
matical Functions' in zshcontrib(1).

The following functions take two floating point arguments: copysign,
fmod, hypot, nextafter.

The following take an integer first argument and a floating point sec-
ond argument: jn, yn.

The following take a floating point first argument and an integer sec-
ond argument: ldexp, scalb.

The function abs does not convert the type of its single argument; it
returns the absolute value of either a floating point number or an in-
teger. The functions float and int convert their arguments into a
floating point or integer value (by truncation) respectively.

Note that the C pow function is available in ordinary math evaluation
as the `**' operator and is not provided here.

The function rand48 is available if your system's mathematical library
has the function erand48(3). It returns a pseudo-random floating point
number between 0 and 1. It takes a single string optional argument.

If the argument is not present, the random number seed is initialised
by three calls to the rand(3) function --- this produces the same ran-
dom numbers as the next three values of $RANDOM.

If the argument is present, it gives the name of a scalar parameter
where the current random number seed will be stored. On the first
call, the value must contain at least twelve hexadecimal digits (the
remainder of the string is ignored), or the seed will be initialised in
the same manner as for a call to rand48 with no argument. Subsequent
calls to rand48(param) will then maintain the seed in the parameter
param as a string of twelve hexadecimal digits, with no base signifier.
The random number sequences for different parameters are completely in-
dependent, and are also independent from that used by calls to rand48
with no argument.

For example, consider

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

Assuming $seed does not exist, it will be initialised by the first
call. In the second call, the default seed is initialised; note, how-
ever, that because of the properties of rand() there is a correlation
between the seeds used for the two initialisations, so for more secure
uses, you should generate your own 12-byte seed. The third call re-
turns to the same sequence of random numbers used in the first call,
unaffected by the intervening rand48().

THE ZSH/NEARCOLOR MODULE
The zsh/nearcolor module replaces colours specified as hex triplets
with the nearest colour in the 88 or 256 colour palettes that are
widely used by terminal emulators. By default, 24-bit true colour es-
cape codes are generated when colours are specified using hex triplets.
These are not supported by all terminals. The purpose of this module
is to make it easier to define colour preferences in a form that can
work across a range of terminal emulators.

Aside from the default colour, the ANSI standard for terminal escape
codes provides for eight colours. The bright attribute brings this to
sixteen. These basic colours are commonly used in terminal applications
due to being widely supported. Expanded 88 and 256 colour palettes are
also common and, while the first sixteen colours vary somewhat between
terminals and configurations, these add a generally consistent and pre-
dictable set of colours.

In order to use the zsh/nearcolor module, it only needs to be loaded.
Thereafter, whenever a colour is specified using a hex triplet, it will
be compared against each of the available colours and the closest will
be selected. The first sixteen colours are never matched in this
process due to being unpredictable.

It isn't possible to reliably detect support for true colour in the
terminal emulator. It is therefore recommended to be selective in load-
ing the zsh/nearcolor module. For example, the following checks the
COLORTERM environment variable:

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

Note that some terminals accept the true color escape codes but map
them internally to a more limited palette in a similar manner to the
zsh/nearcolor module.

THE ZSH/NEWUSER MODULE
The zsh/newuser module is loaded at boot if it is available, the RCS
option is set, and the PRIVILEGED option is not set (all three are true
by default). This takes place immediately after commands in the global
zshenv file (typically /etc/zsh/zshenv), if any, have been executed.
If the module is not available it is silently ignored by the shell; the
module may safely be removed from $MODULE_PATH by the administrator if
it is not required.

On loading, the module tests if any of the start-up files .zshenv,
.zprofile, .zshrc or .zlogin exist in the directory given by the envi-
ronment variable ZDOTDIR, or the user's home directory if that is not
set. The test is not performed and the module halts processing if the
shell was in an emulation mode (i.e. had been invoked as some other
shell than zsh).

If none of the start-up files were found, the module then looks for the
file newuser first in a sitewide directory, usually the parent direc-
tory of the site-functions directory, and if that is not found the mod-
ule searches in a version-specific directory, usually the parent of the
functions directory containing version-specific functions. (These di-
rectories can be configured when zsh is built using the --en-
able-site-scriptdir=dir and --enable-scriptdir=dir flags to configure,
respectively; the defaults are prefix/share/zsh and pre-
fix/share/zsh/$ZSH_VERSION where the default prefix is /usr/local.)

If the file newuser is found, it is then sourced in the same manner as
a start-up file. The file is expected to contain code to install
start-up files for the user, however any valid shell code will be exe-
cuted.

The zsh/newuser module is then unconditionally unloaded.

Note that it is possible to achieve exactly the same effect as the
zsh/newuser module by adding code to /etc/zsh/zshenv. The module ex-
ists simply to allow the shell to make arrangements for new users with-
out the need for intervention by package maintainers and system admin-
istrators.

The script supplied with the module invokes the shell function
zsh-newuser-install. This may be invoked directly by the user even if
the zsh/newuser module is disabled. Note, however, that if the module
is not installed the function will not be installed either. The func-
tion is documented in the section User Configuration Functions in zsh-
contrib(1).

THE ZSH/PARAMETER MODULE
The zsh/parameter module gives access to some of the internal hash ta-
bles used by the shell by defining some special parameters.

options
The keys for this associative array are the names of the options
that can be set and unset using the setopt and unsetopt
builtins. The value of each key is either the string on if the
option is currently set, or the string off if the option is un-
set. Setting a key to one of these strings is like setting or
unsetting the option, respectively. Unsetting a key in this ar-
ray is like setting it to the value off.

commands
This array gives access to the command hash table. The keys are
the names of external commands, the values are the pathnames of
the files that would be executed when the command would be in-
voked. Setting a key in this array defines a new entry in this
table in the same way as with the hash builtin. Unsetting a key
as in `unset "commands[foo]"' removes the entry for the given
key from the command hash table.

functions
This associative array maps names of enabled functions to their
definitions. Setting a key in it is like defining a function
with the name given by the key and the body given by the value.
Unsetting a key removes the definition for the function named by
the key.

dis_functions
Like functions but for disabled functions.

functions_source
This readonly associative array maps names of enabled functions
to the name of the file containing the source of the function.

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

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

For any other function, including any defined at an interactive
prompt or an autoload function whose path has not yet been re-
solved, 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.

dis_functions_source
Like functions_source but for disabled functions.

builtins
This associative array gives information about the builtin com-
mands currently enabled. The keys are the names of the builtin
commands and the values are either `undefined' for builtin com-
mands that will automatically be loaded from a module if invoked
or `defined' for builtin commands that are already loaded.

dis_builtins
Like builtins but for disabled builtin commands.

reswords
This array contains the enabled reserved words.

dis_reswords
Like reswords but for disabled reserved words.

patchars
This array contains the enabled pattern characters.

dis_patchars
Like patchars but for disabled pattern characters.

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

dis_aliases
Like aliases but for disabled regular aliases.

galiases
Like aliases, but for global aliases.

dis_galiases
Like galiases but for disabled global aliases.

saliases
Like raliases, but for suffix aliases.

dis_saliases
Like saliases but for disabled suffix aliases.

parameters
The keys in this associative array are the names of the parame-
ters currently defined. The values are strings describing the
type of the parameter, in the same format used by the t parame-
ter flag, see zshexpn(1) . Setting or unsetting keys in this
array is not possible.

modules
An associative array giving information about modules. The keys
are the names of the modules loaded, registered to be au-
toloaded, or aliased. The value says which state the named mod-
ule is in and is one of the strings `loaded', `autoloaded', or
`alias:name', where name is the name the module is aliased to.

Setting or unsetting keys in this array is not possible.

dirstack
A normal array holding the elements of the directory stack. Note
that the output of the dirs builtin command includes one more
directory, the current working directory.

history
This associative array maps history event numbers to the full
history lines. Although it is presented as an associative ar-
ray, the array of all values (${history[@]}) is guaranteed to be
returned in order from most recent to oldest history event, that
is, by decreasing history event number.

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

jobdirs
This associative array maps job numbers to the directories from
which the job was started (which may not be the current direc-
tory of the job).

The keys of the associative arrays are usually valid job num-
bers, 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.

jobtexts
This associative array maps job numbers to the texts of the com-
mand lines that were used to start the jobs.

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

jobstates
This associative array gives information about the states of the
jobs currently known. The keys are the job numbers and the val-
ues are strings of the form `job-state:mark:pid=state...'. The
job-state gives the state the whole job is currently in, one of
`running', `suspended', or `done'. The mark is `+' for the cur-
rent job, `-' for the previous job and empty otherwise. This is
followed by one `:pid=state' for every process in the job. The
pids are, of course, the process IDs and the state describes the
state of that process.

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

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

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

usergroups
This associative array maps names of system groups of which the
current user is a member to the corresponding group identifiers.
The contents are the same as the groups output by the id com-
mand.

funcfiletrace
This array contains the absolute line numbers and corresponding
file names for the point where the current function, sourced
file, or (if EVAL_LINENO is set) eval command was called. The
array is of the same length as funcsourcetrace and functrace,
but differs from funcsourcetrace in that the line and file are
the point of call, not the point of definition, and differs from
functrace in that all values are absolute line numbers in files,
rather than relative to the start of a function, if any.

funcsourcetrace
This array contains the file names and line numbers of the
points where the functions, sourced files, and (if EVAL_LINENO
is set) eval commands currently being executed were defined.
The line number is the line where the `function name' or `name
()' started. In the case of an autoloaded function the line
number is reported as zero. The format of each element is file-
name:lineno.

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

Most users will be interested in the information in the func-
filetrace array instead.

funcstack
This array contains the names of the functions, sourced files,
and (if EVAL_LINENO is set) eval commands. currently being exe-
cuted. The first element is the name of the function using the
parameter.

The standard shell array zsh_eval_context can be used to deter-
mine the type of shell construct being executed at each depth:
note, however, that is in the opposite order, with the most re-
cent 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 $func-
stack.

functrace
This array contains the names and line numbers of the callers
corresponding to the functions currently being executed. The
format of each element is name:lineno. Callers are also shown
for sourced files; the caller is the point where the source or
`.' command was executed.

THE ZSH/PCRE MODULE
The zsh/pcre module makes some commands available as builtins:

pcre_compile [ -aimxs ] PCRE
Compiles a perl-compatible regular expression.

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

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

pcre_match [ -v var ] [ -a arr ] [ -n offset ] [ -b ] string
Returns successfully if string matches the previously-compiled
PCRE.

Upon successful match, if the expression captures substrings
within parentheses, pcre_match will set the array match to those
substrings, unless the -a option is given, in which case it will
set the array arr. Similarly, the variable MATCH will be set to
the entire matched portion of the string, unless the -v option
is given, in which case the variable var will be set. No vari-
ables 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 nec-
essarily the same as the character position when UTF-8 charac-
ters 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

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

expr -pcre-match pcre
Matches a string against a perl-compatible regular expression.

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, in-
stead use the -i switch of pcre_compile.

THE ZSH/PARAM/PRIVATE MODULE
The zsh/param/private module is used to create parameters whose scope
is limited to the current function body, and not to other functions
called by the current function.

This module provides a single autoloaded builtin:

private [ {+|-}AHUahlprtux ] [ {+|-}EFLRZi [ n ] ] [ name[=value] ... ]
The private builtin accepts all the same options and arguments
as local (zshbuiltins(1)) except for the `-T' option. Tied pa-
rameters may not be made private.

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 parame-
ter. This may change in the future.

As with other typeset equivalents, private is both a builtin and a re-
served word, so arrays may be assigned with parenthesized word list
name=(value...) syntax. However, the reserved word `private' is not
available until zsh/param/private is loaded, so care must be taken with
order of execution and parsing for function definitions which use pri-
vate. To compensate for this, the module also adds the option `-P' to
the `local' builtin to declare private parameters.

For example, this construction fails if zsh/param/private has not yet
been loaded when `bad_declaration' is defined:
bad_declaration() {
zmodload zsh/param/private
private array=( one two three )
}

This construction works because local is already a keyword, and the
module is loaded before the statement is executed:
good_declaration() {
zmodload zsh/param/private
local -P array=( one two three )
}

The following is usable in scripts but may have trouble with autoload:
zmodload zsh/param/private
iffy_declaration() {
private array=( one two three )
}

The private builtin may always be used with scalar assignments and for
declarations without assignments.

Parameters declared with private have the following properties:

o Within the function body where it is declared, the parameter be-
haves as a local, except as noted above for tied or special pa-
rameters.

o The type of a parameter declared private cannot be changed in
the scope where it was declared, even if the parameter is unset.
Thus an array cannot be assigned to a private scalar, etc.

o Within any other function called by the declaring function, the
private parameter does NOT hide other parameters of the same
name, so for example a global parameter of the same name is vis-
ible and may be assigned or unset. This includes calls to
anonymous functions, although that may also change in the fu-
ture.

o An exported private remains in the environment of inner scopes
but appears unset for the current shell in those scopes. Gener-
ally, exporting private parameters should be avoided.

Note that this differs from the static scope defined by compiled lan-
guages derived from C, in that the a new call to the same function cre-
ates a new scope, i.e., the parameter is still associated with the call
stack rather than with the function definition. It differs from ksh
`typeset -S' because the syntax used to define the function has no
bearing on whether the parameter scope is respected.

THE ZSH/REGEX MODULE
The zsh/regex module makes available the following test condition:

expr -regex-match regex
Matches a string against a POSIX extended regular expression.
On successful match, matched portion of the string will normally
be placed in the MATCH variable. If there are any capturing
parentheses within the regex, then the match array variable will
contain those. If the match is not successful, then the vari-
ables will not be altered.

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.

THE ZSH/SCHED MODULE
The zsh/sched module makes available one builtin command and one param-
eter.

sched [-o] [+]hh:mm[:ss] command ...
sched [-o] [+]seconds command ...
sched [ -item ]
Make an entry in the scheduled list of commands to execute. The
time may be specified in either absolute or relative time, and
either as hours, minutes and (optionally) seconds separated by a
colon, or seconds alone. An absolute number of seconds indi-
cates the time since the epoch (1970/01/01 00:00); this is use-
ful in combination with the features in the zsh/datetime module,
see the zsh/datetime module entry in zshmodules(1).

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 lat-
ter 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 emula-
tor'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 edi-
tor 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'.

zsh_scheduled_events
A readonly array corresponding to the events scheduled by the
sched builtin. The indices of the array correspond to the num-
bers shown when sched is run with no arguments (provided that
the KSH_ARRAYS option is not set). The value of the array con-
sists of the scheduled time in seconds since the epoch (see the
section `The zsh/datetime Module' for facilities for using this
number), followed by a colon, followed by any options (which may
be empty but will be preceded by a `-' otherwise), followed by a
colon, followed by the command to be executed.

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

THE ZSH/NET/SOCKET MODULE
The zsh/net/socket module makes available one builtin command:

zsocket [ -altv ] [ -d fd ] [ args ]
zsocket is implemented as a builtin to allow full use of shell
command line editing, file I/O, and job control mechanisms.

Outbound Connections
zsocket [ -v ] [ -d fd ] filename
Open a new Unix domain connection to filename. The shell param-
eter REPLY will be set to the file descriptor associated with
that connection. Currently, only stream connections are sup-
ported.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

File descriptors can be closed with normal shell syntax when no
longer needed, for example:

exec {REPLY}>&-

Inbound Connections
zsocket -l [ -v ] [ -d fd ] filename
zsocket -l will open a socket listening on filename. The shell
parameter REPLY will be set to the file descriptor associated
with that listener. The file descriptor remains open in sub-
shells and forked external executables.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

zsocket -a [ -tv ] [ -d targetfd ] listenfd
zsocket -a will accept an incoming connection to the socket as-
sociated with listenfd. The shell parameter REPLY will be set
to the file descriptor associated with the inbound connection.
The file descriptor remains open in subshells and forked exter-
nal executables.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

If -t is specified, zsocket will return if no incoming connec-
tion is pending. Otherwise it will wait for one.

In order to elicit more verbose output, use -v.

THE ZSH/STAT MODULE
The zsh/stat module makes available one builtin command under two pos-
sible names:

zstat [ -gnNolLtTrs ] [ -f fd ] [ -H hash ] [ -A array ] [ -F fmt ]
[ +element ] [ file ... ]
stat ...
The command acts as a front end to the stat system call (see
stat(2)). The same command is provided with two names; as the
name stat is often used by an external command it is recommended
that only the zstat form of the command is used. This can be
arranged by loading the module with the command `zmodload -F
zsh/stat b:zstat'.

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

device The number of the device on which the file resides.

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

mode The mode of the file; that is, the file's type and access
permissions. With the -s option, this will be returned
as a string corresponding to the first column in the dis-
play 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 op-
tion, 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 pre-
ceded by a `+' in the option list; only one element is allowed.
The element may be shortened to any unique set of leading char-
acters. Otherwise, all elements will be shown for all files.

Options:

-A array
Instead of displaying the results on standard output, as-
sign 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, respec-
tively. 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 preced-
ing all the others. Other formatting options are re-
spected.

-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 for-
matting of the time elements. The format string supports
all of the zsh extensions described in the section EXPAN-
SION OF PROMPT SEQUENCES in zshmisc(1). The -s option is
implied.

-g Show the time elements in the GMT time zone. The -s op-
tion is implied.

-l List the names of the type elements (to standard output
or an array as appropriate) and return immediately; argu-
ments, 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 re-
turned. 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 se-
lected.

-T Never show the type names of the struct stat elements.

THE ZSH/SYSTEM MODULE
The zsh/system module makes available various builtin commands and pa-
rameters.

Builtins
syserror [ -e errvar ] [ -p prefix ] [ errno | errname ]
This command prints out the error message associated with errno,
a system error number, followed by a newline to standard error.

Instead of the error number, a name errname, for example ENOENT,
may be used. The set of names is the same as the contents of
the array errnos, see below.

If the string prefix is given, it is printed in front of the er-
ror message, with no intervening space.

If errvar is supplied, the entire message, without a newline, is
assigned to the parameter names errvar and nothing is output.

A return status of 0 indicates the message was successfully
printed (although it may not be useful if the error number was
out of the system's range), a return status of 1 indicates an
error in the parameters, and a return status of 2 indicates the
error name was not recognised (no message is printed for this).

sysopen [ -arw ] [ -m permissions ] [ -o options ]
-u fd file
This command opens a file. The -r, -w and -a flags indicate
whether the file should be opened for reading, writing and ap-
pending, respectively. The -m option allows the initial permis-
sions to use when creating a file to be specified in octal form.
The file descriptor is specified with -u. Either an explicit
file descriptor in the range 0 to 9 can be specified or a vari-
able name can be given to which the file descriptor number will
be assigned.

The -o option allows various system specific options to be spec-
ified as a comma-separated list. The following is a list of pos-
sible options. Note that, depending on the system, some may not
be available.
cloexec
mark file to be closed when other programs are executed
(else the file descriptor remains open in subshells and
forked external executables)

create
creat create file if it does not exist

excl create file, error if it already exists

noatime
suppress updating of the file atime

nofollow
fail if file is a symbolic link

sync request that writes wait until data has been physically
written

truncate
trunc truncate file to size 0

To close the file, use one of the following:

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

sysread [ -c countvar ] [ -i infd ] [ -o outfd ]
[ -s bufsize ] [ -t timeout ] [ param ]
Perform a single system read from file descriptor infd, or zero
if that is not given. The result of the read is stored in param
or REPLY if that is not given. If countvar is given, the number
of bytes read is assigned to the parameter named by countvar.

The maximum number of bytes read is bufsize or 8192 if that is
not given, however the command returns as soon as any number of
bytes was successfully read.

If timeout is given, it specifies a timeout in seconds, which
may be zero to poll the file descriptor. This is handled by the
poll system call if available, otherwise the select system call
if available.

If outfd is given, an attempt is made to write all the bytes
just read to the file descriptor outfd. If this fails, because
of a system error other than EINTR or because of an internal zsh
error during an interrupt, the bytes read but not written are
stored in the parameter named by param if supplied (no default
is used in this case), and the number of bytes read but not
written is stored in the parameter named by countvar if that is
supplied. If it was successful, countvar contains the full num-
ber of bytes transferred, as usual, and param is not set.

The error EINTR (interrupted system call) is handled internally
so that shell interrupts are transparent to the caller. Any
other error causes a return.

The possible return statuses are
0 At least one byte of data was successfully read and, if
appropriate, written.

1 There was an error in the parameters to the command.
This is the only error for which a message is printed to
standard error.

2 There was an error on the read, or on polling the input
file descriptor for a timeout. The parameter ERRNO gives
the error.

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

4 The attempt to read timed out. Note this does not set
ERRNO as this is not a system error.

5 No system error occurred, but zero bytes were read. This
usually indicates end of file. The parameters are set
according to the usual rules; no write to outfd is at-
tempted.

sysseek [ -u fd ] [ -w start|end|current ] offset
The current file position at which future reads and writes will
take place is adjusted to the specified byte offset. The offset
is evaluated as a math expression. The -u option allows the file
descriptor to be specified. By default the offset is specified
relative to the start or the file but, with the -w option, it is
possible to specify that the offset should be relative to the
current position or the end of the file.

syswrite [ -c countvar ] [ -o outfd ] data
The data (a single string of bytes) are written to the file de-
scriptor outfd, or 1 if that is not given, using the write sys-
tem call. Multiple write operations may be used if the first
does not write all the data.

If countvar is given, the number of byte written is stored in
the parameter named by countvar; this may not be the full length
of data if an error occurred.

The error EINTR (interrupted system call) is handled internally
by retrying; otherwise an error causes the command to return.
For example, if the file descriptor is set to non-blocking out-
put, an error EAGAIN (on some systems, EWOULDBLOCK) may result
in the command returning early.

The return status may be 0 for success, 1 for an error in the
parameters to the command, or 2 for an error on the write; no
error message is printed in the last case, but the parameter ER-
RNO will reflect the error that occurred.

zsystem flock [ -t timeout ] [ -f var ] [-er] file
zsystem flock -u fd_expr
The builtin zsystem's subcommand flock performs advisory file
locking (via the fcntl(2) system call) over the entire contents
of the given file. This form of locking requires the processes
accessing the file to cooperate; its most obvious use is between
two instances of the shell itself.

In the first form the named file, which must already exist, is
locked by opening a file descriptor to the file and applying a
lock to the file descriptor. The lock terminates when the shell
process that created the lock exits; it is therefore often con-
venient to create file locks within subshells, since the lock is
automatically released when the subshell exits. Note that use
of the print builtin with the -u option will, as a side effect,
release the lock, as will redirection to the file in the shell
holding the lock. To work around this use a subshell, e.g.
`(print message) >> file'. Status 0 is returned if the lock
succeeds, else status 1.

In the second form the file descriptor given by the arithmetic
expression fd_expr is closed, releasing a lock. The file de-
scriptor can be queried by using the `-f var' form during the
lock; on a successful lock, the shell variable var is set to the
file descriptor used for locking. The lock will be released if
the file descriptor is closed by any other means, for example
using `exec {var}>&-'; however, the form described here performs
a safety check that the file descriptor is in use for file lock-
ing.

By default the shell waits indefinitely for the lock to succeed.
The option -t timeout specifies a timeout for the lock in sec-
onds; currently this must be an integer. The shell will attempt
to lock the file once a second during this period. If the at-
tempt times out, status 2 is returned.

If the option -e is given, the file descriptor for the lock is
preserved when the shell uses exec to start a new process; oth-
erwise it is closed at that point and the lock released.

If the option -r is given, the lock is only for reading, other-
wise it is for reading and writing. The file descriptor is
opened accordingly.

zsystem supports subcommand
The builtin zsystem's subcommand supports tests whether a given
subcommand is supported. It returns status 0 if so, else status
1. It operates silently unless there was a syntax error (i.e.
the wrong number of arguments), in which case status 255 is re-
turned. Status 1 can indicate one of two things: subcommand is
known but not supported by the current operating system, or sub-
command is not known (possibly because this is an older version
of the shell before it was implemented).

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

Parameters
errnos A readonly array of the names of errors defined on the system.
These are typically macros defined in C by including the system
header file errno.h. The index of each name (assuming the op-
tion KSH_ARRAYS is unset) corresponds to the error number. Er-
ror numbers num before the last known error which have no name
are given the name Enum in the array.

Note that aliases for errors are not handled; only the canonical
name is used.

sysparams
A readonly associative array. The keys are:

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

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

procsubstpid
Returns the process ID of the last process started for
process substitution, i.e. the <(...) and >(...) expan-
sions.

THE ZSH/NET/TCP MODULE
The zsh/net/tcp module makes available one builtin command:

ztcp [ -acflLtv ] [ -d fd ] [ args ]
ztcp is implemented as a builtin to allow full use of shell com-
mand line editing, file I/O, and job control mechanisms.

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 con-
tents 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 nor-
mal inbound (I) and outbound (O) connections this may be
read and written by the usual shell mechanisms. However,
it should only be close with `ztcp -c'.

Connection type
A letter indicating how the session was created:

Z A session created with the zftp command.

L A connection opened for listening with `ztcp -l'.

I An inbound connection accepted with `ztcp -a'.

O An outbound connection created with `ztcp host
...'.

The local host
This is usually set to an all-zero IP address as the ad-
dress 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 ad-
dress for a session opened for listening.

The remote port
This is zero for a connection opened for listening.

Outbound Connections
ztcp [ -v ] [ -d fd ] host [ port ]
Open a new TCP connection to host. If the port is omitted, it
will default to port 23. The connection will be added to the
session table and the shell parameter REPLY will be set to the
file descriptor associated with that connection.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

Inbound Connections
ztcp -l [ -v ] [ -d fd ] port
ztcp -l will open a socket listening on TCP port. The socket
will be added to the session table and the shell parameter REPLY
will be set to the file descriptor associated with that lis-
tener.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

In order to elicit more verbose output, use -v.

ztcp -a [ -tv ] [ -d targetfd ] listenfd
ztcp -a will accept an incoming connection to the port associ-
ated with listenfd. The connection will be added to the session
table and the shell parameter REPLY will be set to the file de-
scriptor associated with the inbound connection.

If -d is specified, its argument will be taken as the target
file descriptor for the connection.

If -t is specified, ztcp will return if no incoming connection
is pending. Otherwise it will wait for one.

In order to elicit more verbose output, use -v.

Closing Connections
ztcp -cf [ -v ] [ fd ]
ztcp -c [ -v ] [ fd ]
ztcp -c will close the socket associated with fd. The socket
will be removed from the session table. If fd is not specified,
ztcp will close everything in the session table.

Normally, sockets registered by zftp (see zshmodules(1) ) cannot
be closed this way. In order to force such a socket closed, use
-f.

In order to elicit more verbose output, use -v.

Example
Here is how to create a TCP connection between two instances of zsh.
We need to pick an unassigned port; here we use the randomly chosen
5123.

On host1,
zmodload zsh/net/tcp
ztcp -l 5123
listenfd=$REPLY
ztcp -a $listenfd
fd=$REPLY
The second from last command blocks until there is an incoming connec-
tion.

Now create a connection from host2 (which may, of course, be the same
machine):
zmodload zsh/net/tcp
ztcp host1 5123
fd=$REPLY

Now on each host, $fd contains a file descriptor for talking to the
other. For example, on host1:
print This is a message >&$fd
and on host2:
read -r line <&$fd; print -r - $line
prints `This is a message'.

To tidy up, on host1:
ztcp -c $listenfd
ztcp -c $fd
and on host2
ztcp -c $fd

THE ZSH/TERMCAP MODULE
The zsh/termcap module makes available one builtin command:

echotc cap [ arg ... ]
Output the termcap value corresponding to the capability cap,
with optional arguments.

The zsh/termcap module makes available one parameter:

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

THE ZSH/TERMINFO MODULE
The zsh/terminfo module makes available one builtin command:

echoti cap [ arg ]
Output the terminfo value corresponding to the capability cap,
instantiated with arg if applicable.

The zsh/terminfo module makes available one parameter:

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

THE ZSH/ZFTP MODULE
The zsh/zftp module makes available one builtin command:

zftp subcommand [ args ]
The zsh/zftp module is a client for FTP (file transfer proto-
col). It is implemented as a builtin to allow full use of shell
command line editing, file I/O, and job control mechanisms. Of-
ten, users will access it via shell functions providing a more
powerful interface; a set is provided with the zsh distribution
and is described in zshzftpsys(1). However, the zftp command is
entirely usable in its own right.

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

Subcommands
open host[:port] [ user [ password [ account ] ] ]
Open a new FTP session to host, which may be the name of a
TCP/IP connected host or an IP number in the standard dot nota-
tion. If the argument is in the form host:port, open a connec-
tion to TCP port port instead of the standard FTP port 21. This
may be the name of a TCP service or a number: see the descrip-
tion of ZFTP_PORT below for more information.

If IPv6 addresses in colon format are used, the host should be
surrounded by quoted square brackets to distinguish it from the
port, for example '[fe80::203:baff:fe02:8b56]'. For consistency
this is allowed with all forms of host.

Remaining arguments are passed to the login subcommand. Note
that if no arguments beyond host are supplied, open will not au-
tomatically call login. If no arguments at all are supplied,
open will use the parameters set by the params subcommand.

After a successful open, the shell variables ZFTP_HOST,
ZFTP_PORT, ZFTP_IP and ZFTP_SYSTEM are available; see `Vari-
ables' below.

login [ name [ password [ account ] ] ]
user [ name [ password [ account ] ] ]
Login the user name with parameters password and account. Any
of the parameters can be omitted, and will be read from standard
input if needed (name is always needed). If standard input is a
terminal, a prompt for each one will be printed on standard er-
ror and password will not be echoed. If any of the parameters
are not used, a warning message is printed.

After a successful login, the shell variables ZFTP_USER,
ZFTP_ACCOUNT and ZFTP_PWD are available; see `Variables' below.

This command may be re-issued when a user is already logged in,
and the server will first be reinitialized for a new user.

params [ host [ user [ password [ account ] ] ] ]
params -
Store the given parameters for a later open command with no ar-
guments. Only those given on the command line will be remem-
bered. If no arguments are given, the parameters currently set
are printed, although the password will appear as a line of
stars; the return status is one if no parameters were set, zero
otherwise.

Any of the parameters may be specified as a `?', which may need
to be quoted to protect it from shell expansion. In this case,
the appropriate parameter will be read from stdin as with the
login subcommand, including special handling of password. If
the `?' is followed by a string, that is used as the prompt for
reading the parameter instead of the default message (any neces-
sary punctuation and whitespace should be included at the end of
the prompt). The first letter of the parameter (only) may be
quoted with a `\'; hence an argument "\\$word" guarantees that
the string from the shell parameter $word will be treated liter-
ally, whether or not it begins with a `?'.

If instead a single `-' is given, the existing parameters, if
any, are deleted. In that case, calling open with no arguments
will cause an error.

The list of parameters is not deleted after a close, however it
will be deleted if the zsh/zftp module is unloaded.

For example,

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

will store the host ftp.elsewhere.xx and the user juser and then
prompt the user for the corresponding password with the given
prompt.

test Test the connection; if the server has reported that it has
closed the connection (maybe due to a timeout), return status 2;
if no connection was open anyway, return status 1; else return
status 0. The test subcommand is silent, apart from messages
printed by the $ZFTP_VERBOSE mechanism, or error messages if the
connection closes. There is no network overhead for this test.

The test is only supported on systems with either the select(2)
or poll(2) system calls; otherwise the message `not supported on
this system' is printed instead.

The test subcommand will automatically be called at the start of
any other subcommand for the current session when a connection
is open.

cd directory
Change the remote directory to directory. Also alters the shell
variable ZFTP_PWD.

cdup Change the remote directory to the one higher in the directory
tree. Note that cd .. will also work correctly on non-UNIX sys-
tems.

dir [ arg ... ]
Give a (verbose) listing of the remote directory. The args are
passed directly to the server. The command's behaviour is imple-
mentation dependent, but a UNIX server will typically interpret
args as arguments to the ls command and with no arguments return
the result of `ls -l'. The directory is listed to standard out-
put.

ls [ arg ... ]
Give a (short) listing of the remote directory. With no arg,
produces a raw list of the files in the directory, one per line.
Otherwise, up to vagaries of the server implementation, behaves
similar to dir.

type [ type ]
Change the type for the transfer to type, or print the current
type if type is absent. The allowed values are `A' (ASCII), `I'
(Image, i.e. binary), or `B' (a synonym for `I').

The FTP default for a transfer is ASCII. However, if zftp finds
that the remote host is a UNIX machine with 8-bit byes, it will
automatically switch to using binary for file transfers upon
open. This can subsequently be overridden.

The transfer type is only passed to the remote host when a data
connection is established; this command involves no network
overhead.

ascii The same as type A.

binary The same as type I.

mode [ S | B ]
Set the mode type to stream (S) or block (B). Stream mode is
the default; block mode is not widely supported.

remote file ...
local [ file ... ]
Print the size and last modification time of the remote or local
files. If there is more than one item on the list, the name of
the file is printed first. The first number is the file size,
the second is the last modification time of the file in the for-
mat CCYYMMDDhhmmSS consisting of year, month, date, hour, min-
utes and seconds in GMT. Note that this format, including the
length, is guaranteed, so that time strings can be directly com-
pared via the [[ builtin's < and > operators, even if they are
too long to be represented as integers.

Not all servers support the commands for retrieving this infor-
mation. In that case, the remote command will print nothing and
return status 2, compared with status 1 for a file not found.

The local command (but not remote) may be used with no argu-
ments, in which case the information comes from examining file
descriptor zero. This is the same file as seen by a put command
with no further redirection.

get file ...
Retrieve all files from the server, concatenating them and send-
ing them to standard output.

put file ...
For each file, read a file from standard input and send that to
the remote host with the given name.

append file ...
As put, but if the remote file already exists, data is appended
to it instead of overwriting it.

getat file point
putat file point
appendat file point
Versions of get, put and append which will start the transfer at
the given point in the remote file. This is useful for append-
ing to an incomplete local file. However, note that this abil-
ity is not universally supported by servers (and is not quite
the behaviour specified by the standard).

delete file ...
Delete the list of files on the server.

mkdir directory
Create a new directory directory on the server.

rmdir directory
Delete the directory directory on the server.

rename old-name new-name
Rename file old-name to new-name on the server.

site arg ...
Send a host-specific command to the server. You will probably
only need this if instructed by the server to use it.

quote arg ...
Send the raw FTP command sequence to the server. You should be
familiar with the FTP command set as defined in RFC959 before
doing this. Useful commands may include STAT and HELP. Note
also the mechanism for returning messages as described for the
variable ZFTP_VERBOSE below, in particular that all messages
from the control connection are sent to standard error.

close
quit Close the current data connection. This unsets the shell param-
eters ZFTP_HOST, ZFTP_PORT, ZFTP_IP, ZFTP_SYSTEM, ZFTP_USER,
ZFTP_ACCOUNT, ZFTP_PWD, ZFTP_TYPE and ZFTP_MODE.

session [ sessname ]
Allows multiple FTP sessions to be used at once. The name of
the session is an arbitrary string of characters; the default
session is called `default'. If this command is called without
an argument, it will list all the current sessions; with an ar-
gument, it will either switch to the existing session called
sessname, or create a new session of that name.

Each session remembers the status of the connection, the set of
connection-specific shell parameters (the same set as are unset
when a connection closes, as given in the description of close),
and any user parameters specified with the params subcommand.
Changing to a previous session restores those values; changing
to a new session initialises them in the same way as if zftp had
just been loaded. The name of the current session is given by
the parameter ZFTP_SESSION.

rmsession [ sessname ]
Delete a session; if a name is not given, the current session is
deleted. If the current session is deleted, the earliest exist-
ing session becomes the new current session, otherwise the cur-
rent session is not changed. If the session being deleted is
the only one, a new session called `default' is created and be-
comes the current session; note that this is a new session even
if the session being deleted is also called `default'. It is
recommended that sessions not be deleted while background com-
mands which use zftp are still active.

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

ZFTP_TMOUT
Integer. The time in seconds to wait for a network operation to
complete before returning an error. If this is not set when the
module is loaded, it will be given the default value 60. A
value of zero turns off timeouts. If a timeout occurs on the
control connection it will be closed. Use a larger value if
this occurs too frequently.

ZFTP_IP
Readonly. The IP address of the current connection in dot nota-
tion.

ZFTP_HOST
Readonly. The hostname of the current remote server. If the
host was opened as an IP number, ZFTP_HOST contains that in-
stead; this saves the overhead for a name lookup, as IP numbers
are most commonly used when a nameserver is unavailable.

ZFTP_PORT
Readonly. The number of the remote TCP port to which the con-
nection is open (even if the port was originally specified as a
named service). Usually this is the standard FTP port, 21.

In the unlikely event that your system does not have the appro-
priate conversion functions, this appears in network byte order.
If your system is little-endian, the port then consists of two
swapped bytes and the standard port will be reported as 5376.
In that case, numeric ports passed to zftp open will also need
to be in this format.

ZFTP_SYSTEM
Readonly. The system type string returned by the server in re-
sponse to an FTP SYST request. The most interesting case is a
string beginning "UNIX Type: L8", which ensures maximum compati-
bility with a local UNIX host.

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

ZFTP_USER
Readonly. The username currently logged in, if any.

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

ZFTP_PWD
Readonly. The current directory on the server.

ZFTP_CODE
Readonly. The three digit code of the last FTP reply from the
server as a string. This can still be read after the connection
is closed, and is not changed when the current session changes.

ZFTP_REPLY
Readonly. The last line of the last reply sent by the server.
This can still be read after the connection is closed, and is
not changed when the current session changes.

ZFTP_SESSION
Readonly. The name of the current FTP session; see the descrip-
tion of the session subcommand.

ZFTP_PREFS
A string of preferences for altering aspects of zftp's behav-
iour. Each preference is a single character. The following are
defined:

P Passive: attempt to make the remote server initiate data
transfers. This is slightly more efficient than sendport
mode. If the letter S occurs later in the string, zftp
will use sendport mode if passive mode is not available.

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

D Dumb: use only the bare minimum of FTP commands. This
prevents the variables ZFTP_SYSTEM and ZFTP_PWD from be-
ing set, and will mean all connections default to ASCII
type. It may prevent ZFTP_SIZE from being set during a
transfer if the server does not send it anyway (many
servers do).

If ZFTP_PREFS is not set when zftp is loaded, it will be set to
a default of `PS', i.e. use passive mode if available, otherwise
fall back to sendport mode.

ZFTP_VERBOSE
A string of digits between 0 and 5 inclusive, specifying which
responses from the server should be printed. All responses go
to standard error. If any of the numbers 1 to 5 appear in the
string, raw responses from the server with reply codes beginning
with that digit will be printed to standard error. The first
digit of the three digit reply code is defined by RFC959 to cor-
respond to:

1. A positive preliminary reply.

2. A positive completion reply.

3. A positive intermediate reply.

4. A transient negative completion reply.

5. A permanent negative completion reply.

It should be noted that, for unknown reasons, the reply `Service
not available', which forces termination of a connection, is
classified as 421, i.e. `transient negative', an interesting in-
terpretation of the word `transient'.

The code 0 is special: it indicates that all but the last line
of multiline replies read from the server will be printed to
standard error in a processed format. By convention, servers
use this mechanism for sending information for the user to read.
The appropriate reply code, if it matches the same response,
takes priority.

If ZFTP_VERBOSE is not set when zftp is loaded, it will be set
to the default value 450, i.e., messages destined for the user
and all errors will be printed. A null string is valid and
specifies that no messages should be printed.

Functions
zftp_chpwd
If this function is set by the user, it is called every time the
directory changes on the server, including when a user is logged
in, or when a connection is closed. In the last case, $ZFTP_PWD
will be unset; otherwise it will reflect the new directory.

zftp_progress
If this function is set by the user, it will be called during a
get, put or append operation each time sufficient data has been
received from the host. During a get, the data is sent to stan-
dard output, so it is vital that this function should write to
standard error or directly to the terminal, not to standard out-
put.

When it is called with a transfer in progress, the following ad-
ditional shell parameters are set:

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

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

ZFTP_SIZE
The total size of the complete file being transferred:
the same as the first value provided by the remote and
local subcommands for a particular file. If the server
cannot supply this value for a remote file being re-
trieved, it will not be set. If input is from a pipe the
value may be incorrect and correspond simply to a full
pipe buffer.

ZFTP_COUNT
The amount of data so far transferred; a number between
zero and $ZFTP_SIZE, if that is set. This number is al-
ways available.

The function is initially called with ZFTP_TRANSFER set appro-
priately and ZFTP_COUNT set to zero. After the transfer is fin-
ished, the function will be called one more time with
ZFTP_TRANSFER set to GF or PF, in case it wishes to tidy up. It
is otherwise never called twice with the same value of
ZFTP_COUNT.

Sometimes the progress meter may cause disruption. It is up to
the user to decide whether the function should be defined and to
use unfunction when necessary.

Problems
A connection may not be opened in the left hand side of a pipe as this
occurs in a subshell and the file information is not updated in the
main shell. In the case of type or mode changes or closing the connec-
tion in a subshell, the information is returned but variables are not
updated until the next call to zftp. Other status changes in subshells
will not be reflected by changes to the variables (but should be other-
wise harmless).

Deleting sessions while a zftp command is active in the background can
have unexpected effects, even if it does not use the session being
deleted. This is because all shell subprocesses share information on
the state of all connections, and deleting a session changes the order-
ing of that information.

On some operating systems, the control connection is not valid after a
fork(), so that operations in subshells, on the left hand side of a
pipeline, or in the background are not possible, as they should be.
This is presumably a bug in the operating system.

THE ZSH/ZLE MODULE
The zsh/zle module contains the Zsh Line Editor. See zshzle(1).

THE ZSH/ZLEPARAMETER MODULE
The zsh/zleparameter module defines two special parameters that can be
used to access internal information of the Zsh Line Editor (see zsh-
zle(1)).

keymaps
This array contains the names of the keymaps currently defined.

widgets
This associative array contains one entry per widget. The name
of the widget is the key and the value gives information about
the widget. It is either
the string `builtin' for builtin widgets,
a string of the form `user:name' for user-defined widgets,
where name is the name of the shell function implementing
the widget,
a string of the form `completion:type:name'
for completion widgets,
or a null value if the widget is not yet fully defined. In
the penultimate case, type is the name of the builtin widget the
completion widget imitates in its behavior and name is the name
of the shell function implementing the completion widget.

THE ZSH/ZPROF MODULE
When loaded, the zsh/zprof causes shell functions to be profiled. The
profiling results can be obtained with the zprof builtin command made
available by this module. There is no way to turn profiling off other
than unloading the module.

zprof [ -c ]
Without the -c option, zprof lists profiling results to standard
output. The format is comparable to that of commands like
gprof.

At the top there is a summary listing all functions that were
called at least once. This summary is sorted in decreasing or-
der 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 in-
dented 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 invoca-
tions 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 in-
ternal counters and will not show the listing.

THE ZSH/ZPTY MODULE
The zsh/zpty module offers one builtin:

zpty [ -e ] [ -b ] name [ arg ... ]
The arguments following name are concatenated with spaces be-
tween, then executed as a command, as if passed to the eval
builtin. The command runs under a newly assigned pseudo-termi-
nal; this is useful for running commands non-interactively which
expect an interactive environment. The name is not part of the
command, but is used to refer to this command in later calls to
zpty.

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

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

The shell parameter REPLY is set to the file descriptor assigned
to the master side of the pseudo-terminal. This allows the ter-
minal to be monitored with ZLE descriptor handlers (see zsh-
zle(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.

zpty -d [ name ... ]
The second form, with the -d option, is used to delete commands
previously started, by supplying a list of their names. If no
name is given, all commands are deleted. Deleting a command
causes the HUP signal to be sent to the corresponding process.

zpty -w [ -n ] name [ string ... ]
The -w option can be used to send the to command name the given
strings as input (separated by spaces). If the -n option is not
given, a newline is added at the end.

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

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

zpty -r [ -mt ] name [ param [ pattern ] ]
The -r option can be used to read the output of the command
name. With only a name argument, the output read is copied to
the standard output. Unless the pseudo-terminal is non-block-
ing, copying continues until the command under the pseudo-termi-
nal exits; when non-blocking, only as much output as is immedi-
ately available is copied. The return status is zero if any
output is copied.

When also given a param argument, at most one line is read and
stored in the parameter named param. Less than a full line may
be read if the pseudo-terminal is non-blocking. The return sta-
tus 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 pat-
tern, or if the command has exited but at least one character
could still be read. If the option -m is present, the return
status is zero only if the pattern matches. As of this writing,
a maximum of one megabyte of output can be consumed this way; if
a full megabyte is read without matching the pattern, the return
status is non-zero.

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

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

zpty -t name
The -t option without the -r option can be used to test whether
the command name is still running. It returns a zero status if
the command is running and a non-zero value otherwise.

zpty [ -L ]
The last form, without any arguments, is used to list the com-
mands currently defined. If the -L option is given, this is
done in the form of calls to the zpty builtin.

THE ZSH/ZSELECT MODULE
The zsh/zselect module makes available one builtin command:

zselect [ -rwe ] [ -t timeout ] [ -a array ] [ -A assoc ] [ fd ... ]
The zselect builtin is a front-end to the `select' system call,
which blocks until a file descriptor is ready for reading or
writing, or has an error condition, with an optional timeout.
If this is not available on your system, the command prints an
error message and returns status 2 (normal errors return status
1). For more information, see your systems documentation for
select(3). Note there is no connection with the shell builtin
of the same name.

Arguments and options may be intermingled in any order. Non-op-
tion arguments are file descriptors, which must be decimal inte-
gers. By default, file descriptors are to be tested for read-
ing, i.e. zselect will return when data is available to be read
from the file descriptor, or more precisely, when a read opera-
tion 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 in-
dicate 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 zse-
lect. 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 re-
quested 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.

THE ZSH/ZUTIL MODULE
The zsh/zutil module only adds some builtins:

zstyle [ -L [ metapattern [ style ] ] ]
zstyle [ -e | - | -- ] pattern style string ...
zstyle -d [ pattern [ style ... ] ]
zstyle -g name [ pattern [ style ] ]
zstyle -{a|b|s} context style name [ sep ]
zstyle -{T|t} context style [ string ... ]
zstyle -m context style pattern
This builtin command is used to define and lookup styles.
Styles are pairs of names and values, where the values consist
of any number of strings. They are stored together with pat-
terns and lookup is done by giving a string, called the `con-
text', which is matched against the patterns. The definition
stored for the most specific pattern that matches will be re-
turned.

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 char-
acters 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, to define your preferred form of precipitation de-
pending on which city you're in, you might set the following in
your zshrc:

zstyle ':weather:europe:*' preferred-precipitation rain
zstyle ':weather:europe:germany:* preferred-precipitation none
zstyle ':weather:europe:germany:*:munich' preferred-precipitation snow

Then, the fictional `weather' plugin might run under the hood a
command such as

zstyle -s ":weather:${continent}:${country}:${county}:${city}" preferred-precipitation REPLY

in order to retrieve your preference into the scalar variable
$REPLY.

Usage

The forms that operate on patterns are the following.

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

If the -L option is given, listing is done in the form of
calls to zstyle. The optional first argument, metapat-
tern, is a pattern which will be matched against the
string supplied as pattern when the style was defined.
Note: this means, for example, `zstyle -L ":comple-
tion:*"' will match any supplied pattern beginning `:com-
pletion:', not just ":completion:*": use ':comple-
tion:\*' to match that. The optional second argument
limits the output to a specific style (not a pattern).
-L is not compatible with any other options.

zstyle [ - | -- | -e ] pattern style string ...
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 re-
sulting 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 evalua-
tion. 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 defini-
tions 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 in-
terpreted as a string. If the value contains several
strings they are concatenated with spaces (or with the
sep string if that is given) between them.

Return 0 if the style is set, 1 otherwise.

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

Return 0 if name is set to `yes', 1 otherwise.

zstyle -a context style name
The value is stored in name as an array. If name is de-
clared as an associative array, the first, third, etc.
strings are used as the keys and the other strings are
used as the values.

Return 0 if the style is set, 1 otherwise.

zstyle -t context style [ string ... ]
zstyle -T context style [ string ... ]
Test the value of a style, i.e. the -t option only re-
turns 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.

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

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

zformat -f param format spec ...
zformat -a array sep spec ...
This builtin provides two different forms of formatting. The
first form is selected with the -f option. In this case the for-
mat string will be modified by replacing sequences starting with
a percent sign in it with strings from the specs. Each spec
should be of the form `char:string' which will cause every ap-
pearance of the sequence `%char' in format to be replaced by the
string. The `%' sequence may also contain optional minimum and
maximum field width specifications between the `%' and the
`char' in the form `%min.maxc', i.e. the minimum field width is
given first and if the maximum field width is used, it has to be
preceded by a dot. Specifying a minimum field width makes the
result be padded with spaces to the right if the string is
shorter than the requested width. Padding to the left can be
achieved by giving a negative minimum field width. If a maximum
field width is specified, the string will be truncated after
that many characters. After all `%' sequences for the given
specs have been processed, the resulting string is stored in the
parameter param.

The %-escapes also understand ternary expressions in the form
used by prompts. The % is followed by a `(' and then an ordi-
nary 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 for-
mat specifier, which is followed by a piece of `true' text, the
delimiter character again, a piece of `false' text, and a clos-
ing parenthesis. The complete expression (without the digits)
thus looks like `%(X.text1.text2)', except that the `.' charac-
ter is arbitrary. The value given for the format specifier in
the char:string expressions is evaluated as a mathematical ex-
pression, 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.

The second 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.

zregexparse
This implements some internals of the _regex_arguments function.

zparseopts [ -D -E -F -K -M ] [ -a array ] [ -A assoc ] [ - ] spec ...
This builtin simplifies the parsing of options in positional pa-
rameters, i.e. the set of arguments given by $*. Each spec de-
scribes one option and must be of the form `opt[=array]'. If an
option described by opt is found in the positional parameters it
is copied into the array specified with the -a option; if the
optional `=array' is given, it is instead copied into that ar-
ray, which should be declared as a normal array and never as an
associative array.

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

Unless the -E option is given, parsing stops at the first string
that isn't described by one of the 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 exam-
ple, a `--file' option is represented by a name of
`-file'.

If a `+' appears after name, the option is appended to
array each time it is found in the positional parameters;
without the `+' only the last occurrence of the option is
preserved.

If one of these forms is used, the option takes no argu-
ment, so parsing stops if the next positional parameter
does not also begin with `-' (unless the -E option is
used).

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

An optional argument is put into the same array element
as the option name (note that this makes empty strings as
arguments indistinguishable). A mandatory argument is
added as a separate element unless the `:-' form is used,
in which case the argument is put into the same element.

A `+' as described above may appear between the name and
the first colon.

In all cases, option-arguments must appear either immediately
following the option in the same positional parameter or in the
next one. Even an optional argument may appear in the next pa-
rameter, unless it begins with a `-'. There is no special han-
dling 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 -foo-
bar' (for example) is unambiguous. However, due to the aforemen-
tioned 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 vali-
dation for the given options.

Note that the appearance in the positional parameters of
an option without its required argument always aborts
parsing and returns an error as described above regard-
less of whether this option is used.

-K With this option, the arrays specified with the -a option
and with the `=array' forms are kept unchanged when none
of the specs for them is used. Otherwise the entire ar-
ray is replaced when any of the specs is used. Individ-
ual 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 val-
ues are stored, not the way $* is parsed, so results may
be unpredictable if the `name+' specifier is used incon-
sistently.

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 posi-
tional 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)

zsh 5.8 February 14, 2020 ZSHMODULES(1)