Windows PowerShell command on Get-command zshcompsys

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User Commands ZSHCOMPSYS(1)

NAME

zshcompsys - zsh completion system

DESCRIPTION

This describes the shell code for the `new' completion sys-

tem, referred to as compsys. It is written in shell func-

tions based on the features described in zshcompwid(1). The features are contextual, sensitive to the point at which

completion is started. Many completions are already pro-

vided. For this reason, a user can perform a great many tasks without knowing any details beyond how to initialize the system, which is described below in INITIALIZATION. The context that decides what completion is to be performed may be +o an argument or option position: these describe the position on the command line at which completion is requested. For example `first argument to rmdir, the word being completed names a directory'; +o a special context, denoting an element in the shell's syntax. For example `a word in command position' or `an array subscript'. A full context specification contains other elements, as we shall describe. Besides commands names and contexts, the system employs two more concepts, styles and tags. These provide ways for the user to configure the system's behaviour.

Tags play a dual role. They serve as a classification sys-

tem for the matches, typically indicating a class of object that the user may need to distinguish. For example, when completing arguments of the ls command the user may prefer to try files before directories, so both of these are tags. They also appear as the rightmost element in a context specification. Styles modify various operations of the completion system, such as output formatting, but also what kinds of completers are used (and in what order), or which tags are examined. Styles may accept arguments and are manipulated using the zstyle command described in see zshmodules(1). In summary, tags describe what the completion objects are, and style how they are to be completed. At various points of execution, the completion system checks what styles and/or tags are defined for the current context, and uses zsh 4.3.10 Last change: June 1, 2009 1 User Commands ZSHCOMPSYS(1)

that to modify its behavior. The full description of con-

text handling, which determines how tags and other elements of the context influence the behaviour of styles, is described below in COMPLETION SYSTEM CONFIGURATION. When a completion is requested, a dispatcher function is

called; see the description of _main_complete in the list of

control functions below. This dispatcher decides which func-

tion should be called to produce the completions, and calls

it. The result is passed to one or more completers, func-

tions that implement individual completion strategies: sim-

ple completion, error correction, completion with error correction, menu selection, etc.

More generally, the shell functions contained in the comple-

tion system are of two types: +o those beginning `comp' are to be called directly; there are only a few of these;

+o those beginning `_' are called by the completion code.

The shell functions of this set, which implement com-

pletion behaviour and may be bound to keystrokes, are referred to as `widgets'. These proliferate as new completions are required. INITIALIZATION If the system was installed completely, it should be enough to call the shell function compinit from your initialization

file; see the next section. However, the function compin-

stall can be run by a user to configure various aspects of the completion system. Usually, compinstall will insert code into .zshrc, although if that is not writable it will save it in another file and tell you that file's location. Note that it is up to you to make sure that the lines added to .zshrc are actually run; you may, for example, need to move them to an earlier place in the file if .zshrc usually returns early. So long as you keep them all together (including the comment lines at the start and finish), you can rerun compinstall and it will correctly locate and modify these lines. Note, however, that any code you add to this section by hand is likely to be lost if you rerun compinstall, although lines using the command `zstyle' should be gracefully handled. The new code will take effect next time you start the shell, or run .zshrc by hand; there is also an option to make them take effect immediately. However, if compinstall has removed definitions, you will need to restart the shell to see the changes. zsh 4.3.10 Last change: June 1, 2009 2 User Commands ZSHCOMPSYS(1) To run compinstall you will need to make sure it is in a directory mentioned in your fpath parameter, which should already be the case if zsh was properly configured as long

as your startup files do not remove the appropriate direc-

tories from fpath. Then it must be autoloaded (`autoload -U

compinstall' is recommended). You can abort the installa-

tion any time you are being prompted for information, and your .zshrc will not be altered at all; changes only take place right at the end, where you are specifically asked for confirmation. Use of compinit This section describes the use of compinit to initialize completion for the current session when called directly; if you have run compinstall it will be called automatically from your .zshrc. To initialize the system, the function compinit should be in a directory mentioned in the fpath parameter, and should be

autoloaded (`autoload -U compinit' is recommended), and then

run simply as `compinit'. This will define a few utility functions, arrange for all the necessary shell functions to

be autoloaded, and will then re-define all widgets that do

completion to use the new system. If you use the

menu-select widget, which is part of the zsh/complist

module, you should make sure that that module is loaded before the call to compinit so that that widget is also

re-defined. If completion styles (see below) are set up to

perform expansion as well as completion by default, and the

TAB key is bound to expand-or-complete, compinit will rebind

it to complete-word; this is necessary to use the correct

form of expansion. Should you need to use the original completion commands, you can still bind keys to the old widgets by putting a `.' in

front of the widget name, e.g. `.expand-or-complete'.

To speed up the running of compinit, it can be made to pro-

duce a dumped configuration that will be read in on future invocations; this is the default, but can be turned off by

calling compinit with the option -D. The dumped file is

.zcompdump in the same directory as the startup files (i.e.

$ZDOTDIR or $HOME); alternatively, an explicit file name can

be given by `compinit -d dumpfile'. The next invocation of

compinit will read the dumped file instead of performing a full initialization. If the number of completion files changes, compinit will recognise this and produce a new dump file. However, if the name of a function or the arguments in the first line of a

#compdef function (as described below) change, it is easiest

to delete the dump file by hand so that compinit will zsh 4.3.10 Last change: June 1, 2009 3 User Commands ZSHCOMPSYS(1)

re-create it the next time it is run. The check performed

to see if there are new functions can be omitted by giving

the option -C. In this case the dump file will only be

created if there isn't one already. The dumping is actually done by another function, compdump, but you will only need to run this yourself if you change the configuration (e.g. using compdef) and then want to dump

the new one. The name of the old dumped file will be remem-

bered for this purpose.

If the parameter _compdir is set, compinit uses it as a

directory where completion functions can be found; this is only necessary if they are not already in the function search path. For security reasons compinit also checks if the completion system would use files not owned by root or by the current

user, or files in directories that are world- or

group-writable or that are not owned by root or by the

current user. If such files or directories are found, com-

pinit will ask if the completion system should really be used. To avoid these tests and make all files found be used

without asking, use the option -u, and to make compinit

silently ignore all insecure files and directories use the

option -i. This security check is skipped entirely when the

-C option is given.

The security check can be retried at any time by running the

function compaudit. This is the same check used by com-

pinit, but when it is executed directly any changes to fpath are made local to the function so they do not persist. The directories to be checked may be passed as arguments; if

none are given, compaudit uses fpath and _compdir to find

completion system directories, adding missing ones to fpath as necessary. To force a check of exactly the directories

currently named in fpath, set _compdir to an empty string

before calling compaudit or compinit.

The function bashcompinit compatibility with bash's pro-

grammable completion system. When run it will define the functions, compgen and complete which correspond to the bash builtins with the same names. It will then be possible to use completion specifications and functions written for bash. Autoloaded files The convention for autoloaded functions used in completion is that they start with an underscore; as already mentioned,

the fpath/FPATH parameter must contain the directory in which they are stored. If zsh was properly installed on

your system, then fpath/FPATH automatically contains the zsh 4.3.10 Last change: June 1, 2009 4 User Commands ZSHCOMPSYS(1) required directories for the standard functions. For incomplete installations, if compinit does not find enough files beginning with an underscore (fewer than twenty) in the search path, it will try to find more by

adding the directory _compdir to the search path. If that

directory has a subdirectory named Base, all subdirectories will be added to the path. Furthermore, if the subdirectory Base has a subdirectory named Core, compinit will add all subdirectories of the subdirectories is to the path: this allows the functions to be in the same format as in the zsh source distribution. When compinit is run, it searches all such files accessible

via fpath/FPATH and reads the first line of each of them. This line should contain one of the tags described below. Files whose first line does not start with one of these tags are not considered to be part of the completion system and will not be treated specially. The tags are:

#compdef names... [ -[pP] patterns... [ -N names... ] ]

The file will be made autoloadable and the function defined in it will be called when completing names, each of which is either the name of a command whose arguments are to be completed or one of a number of

special contexts in the form -context- described below.

Each name may also be of the form `cmd=service'. When completing the command cmd, the function typically behaves as if the command (or special context) service was being completed instead. This provides a way of altering the behaviour of functions that can perform

many different completions. It is implemented by set-

ting the parameter $service when calling the function;

the function may choose to interpret this how it wishes, and simpler functions will probably ignore it.

If the #compdef line contains one of the options -p or

-P, the words following are taken to be patterns. The

function will be called when completion is attempted

for a command or context that matches one of the pat-

terns. The options -p and -P are used to specify pat-

terns to be tried before or after other completions

respectively. Hence -P may be used to specify default

actions.

The option -N is used after a list following -p or -P;

it specifies that remaining words no longer define pat-

terns. It is possible to toggle between the three options as many times as necessary. zsh 4.3.10 Last change: June 1, 2009 5 User Commands ZSHCOMPSYS(1)

#compdef -k style key-sequences...

This option creates a widget behaving like the builtin

widget style and binds it to the given key-sequences,

if any. The style must be one of the builtin widgets

that perform completion, namely complete-word,

delete-char-or-list, expand-or-complete,

expand-or-complete-prefix, list-choices, menu-complete,

menu-expand-or-complete, or reverse-menu-complete. If

the zsh/complist module is loaded (see zshmodules(1))

the widget menu-select is also available.

When one of the key-sequences is typed, the function in

the file will be invoked to generate the matches. Note

that a key will not be re-bound if if it already was

(that is, was bound to something other than

undefined-key). The widget created has the same name

as the file and can be bound to any other keys using bindkey as usual.

#compdef -K widget-name style key-sequences ...

This is similar to -k except that only one

key-sequences argument may be given for each

widget-name style pair. However, the entire set of

three arguments may be repeated with a different set of

arguments. Note in particular that the widget-name

must be distinct in each set. If it does not begin

with `_' this will be added. The widget-name should

not clash with the name of any existing widget: names based on the name of the function are most useful. For example,

#compdef -K _foo_complete complete-word "^X^C" \

_foo_list list-choices "^X^D"

(all on one line) defines a widget _foo_complete for

completion, bound to `^X^C', and a widget _foo_list for

listing, bound to `^X^D'.

#autoload [ options ]

Functions with the #autoload tag are marked for auto-

loading but are not otherwise treated specially. Typi-

cally they are to be called from within one of the com-

pletion functions. Any options supplied will be passed to the autoload builtin; a typical use is +X to force the function to be loaded immediately. Note that the

-U and -z flags are always added implicitly.

The # is part of the tag name and no white space is allowed

after it. The #compdef tags use the compdef function

described below; the main difference is that the name of the function is supplied implicitly. zsh 4.3.10 Last change: June 1, 2009 6 User Commands ZSHCOMPSYS(1) The special contexts for which completion functions can be defined are:

-array-value-

The right hand side of an array-assignment

(`foo=(...)')

-brace-parameter-

The name of a parameter expansion within braces

(`${...}')

-assign-parameter-

The name of a parameter in an assignment, i.e. on the left hand side of an `='

-command-

A word in command position

-condition-

A word inside a condition (`[[...]]')

-default-

Any word for which no other completion is defined

-equal-

A word beginning with an equals sign

-first-

This is tried before any other completion function.

The function called may set the _compskip parameter to

one of various values: all: no further completion is attempted; a string containing the substring patterns: no pattern completion functions will be called; a string containing default: the function for the

`-default-' context will not be called, but functions

defined for commands will

-math-

Inside mathematical contexts, such as `((...))'

-parameter-

The name of a parameter expansion (`$...')

-redirect-

The word after a redirection operator.

-subscript-

The contents of a parameter subscript.

-tilde-

After an initial tilde (`~'), but before the first slash in the word. zsh 4.3.10 Last change: June 1, 2009 7 User Commands ZSHCOMPSYS(1)

-value-

On the right hand side of an assignment.

Default implementations are supplied for each of these con-

texts. In most cases the context -context- is implemented

by a corresponding function _context, for example the con-

text `-tilde-' and the function `_tilde').

The contexts -redirect- and -value- allow extra

context-specific information. (Internally, this is handled

by the functions for each context calling the function

_dispatch.) The extra information is added separated by

commas.

For the -redirect- context, the extra information is in the

form `-redirect-,op,command', where op is the redirection

operator and command is the name of the command on the line. If there is no command on the line yet, the command field will be empty.

For the -value- context, the form is `-value-,name,command',

where name is the name of the parameter. In the case of elements of an associative array, for example `assoc=(key

', name is expanded to `name-key'. In certain special

contexts, such as completing after `make CFLAGS=', the com-

mand part gives the name of the command, here make; other-

wise it is empty. It is not necessary to define fully specific completions as the functions provided will try to generate completions by

progressively replacing the elements with `-default-'. For

example, when completing after `foo=', _value will try

the names `-value-,foo,' (note the empty command part),

`-value-,foo,-default-' and`-value-,-default-,-default-', in

that order, until it finds a function to handle the context. As an example:

compdef '_files -g "*.log"' '-redirect-,2>,-default-'

completes files matching `*.log' after `2> ' for any command with no more specific handler defined. Also:

compdef _foo -value-,-default-,-default-

specifies that _foo provides completions for the values of

parameters for which no special function has been defined.

This is usually handled by the function _value itself.

zsh 4.3.10 Last change: June 1, 2009 8 User Commands ZSHCOMPSYS(1) The same lookup rules are used when looking up styles (as described below); for example

zstyle ':completion:*:*:-redirect-,2>,*:*' file-patterns '*.log'

is another way to make completion after `2> ' complete files matching `*.log'. Functions The following function is defined by compinit and may be called directly. names... ] ]

compdef [ -an ] function names... [ -[pP] patterns... [ -N

compdef -d names...

compdef -k [ -an ] function style key-sequences...

compdef -K [ -an ] function name style key-sequences ...

The first form defines the function to call for comple-

tion in the given contexts as described for the #comp-

def tag above. Alternatively, all the arguments may have the form `cmd=service'. Here service should already have been

defined by `cmd1=service' lines in #compdef files, as

described above. The argument for cmd will be com-

pleted in the same way as service. The function argument may alternatively be a string containing any shell code. The string will be executed using the eval builtin command to generate completions. This provides a way of avoiding having to define a new completion function. For example, to complete files ending in `.h' as arguments to the command foo:

compdef '_files -g "*.h"' foo

The option -n prevents any completions already defined

for the command or context from being overwritten.

The option -d deletes any completion defined for the

command or contexts listed.

The names may also contain -p, -P and -N options as

described for the #compdef tag. The effect on the

argument list is identical, switching between defini-

tions of patterns tried initially, patterns tried finally, and normal commands and contexts.

The parameter $_compskip may be set by any function

defined for a pattern context. If it is set to a value containing the substring `patterns' none of the

pattern-functions will be called; if it is set to a

zsh 4.3.10 Last change: June 1, 2009 9 User Commands ZSHCOMPSYS(1) value containing the substring `all', no other function will be called.

The form with -k defines a widget with the same name as

the function that will be called for each of the

key-sequences; this is like the #compdef -k tag. The

function should generate the completions needed and will otherwise behave like the builtin widget whose name is given as the style argument. The widgets

usable for this are: complete-word,

delete-char-or-list, expand-or-complete,

expand-or-complete-prefix, list-choices, menu-complete,

menu-expand-or-complete, and reverse-menu-complete, as

well as menu-select if the zsh/complist module is

loaded. The option -n prevents the key being bound if

it is already to bound to something other than

undefined-key.

The form with -K is similar and defines multiple widg-

ets based on the same function, each of which requires the set of three arguments name, style and

key-sequences, where the latter two are as for -k and

the first must be a unique widget name beginning with an underscore.

Wherever applicable, the -a option makes the function

autoloadable, equivalent to autoload -U function.

The function compdef can be used to associate existing com-

pletion functions with new commands. For example,

compdef _pids foo

uses the function _pids to complete process IDs for the com-

mand foo.

Note also the _gnu_generic function described below, which

can be used to complete options for commands that understand

the `--help' option.

COMPLETION SYSTEM CONFIGURATION This section gives a short overview of how the completion

system works, and then more detail on how users can config-

ure how and when matches are generated. Overview When completion is attempted somewhere on the command line the completion system first works out the context. This takes account of a number of things including the command word (such as `grep' or `zsh') and options to which the

current word may be an argument (such as the `-o' option to

zsh which takes a shell option as an argument). zsh 4.3.10 Last change: June 1, 2009 10 User Commands ZSHCOMPSYS(1)

This context information is condensed into a string consist-

ing of multiple fields separated by colons, referred to sim-

ply as `the context' in the remainder of the documentation.

This is used to look up styles, context-sensitive options

that can be used to configure the completion system. The context used for lookup may vary during the same call to the completion system. The context string always consists of a fixed set of fields, separated by colons and with a leading colon before the first, in the form :completion:function:completer:command:argument:tag. These have the following meaning: +o The literal string completion, saying that this style is used by the completion system. This distinguishes

the context from those used by, for example, zle widg-

ets and ZFTP functions. +o The function, if completion is called from a named

widget rather than through the normal completion sys-

tem. Typically this is blank, but it is set by special

widgets such as predict-on and the various functions in

the Widget directory of the distribution to the name of that function, often in an abbreviated form.

+o The completer currently active, the name of the func-

tion without the leading underscore and with other underscores converted to hyphens. A `completer' is in overall control of how completion is to be performed; `complete' is the simplest, but other completers exist to perform related tasks such as correction, or to modify the behaviour of a later completer. See the section `Control Functions' below for more information.

+o The command or a special -context-, just at it appears

following the #compdef tag or the compdef function.

Completion functions for commands that have

sub-commands usually modify this field to contain the

name of the command followed by a minus sign and the

sub-command. For example, the completion function for

the cvs command sets this field to cvs-add when com-

pleting arguments to the add subcommand. +o The argument; this indicates which command line or

option argument we are completing. For command argu-

ments this generally takes the form argument-n, where n

is the number of the argument, and for arguments to zsh 4.3.10 Last change: June 1, 2009 11 User Commands ZSHCOMPSYS(1)

options the form option-opt-n where n is the number of

the argument to option opt. However, this is only the case if the command line is parsed with standard

UNIX-style options and arguments, so many completions

do not set this. +o The tag. As described previously, tags are used to discriminate between the types of matches a completion

function can generate in a certain context. Any com-

pletion function may use any tag name it likes, but a list of the more common ones is given below. The context is gradually put together as the functions are executed, starting with the main entry point, which adds :completion: and the function element if necessary. The completer then adds the completer element. The contextual completion adds the command and argument options. Finally, the tag is added when the types of completion are known. For example, the context name

:completion::complete:dvips:option-o-1:files

says that normal completion was attempted as the first argu-

ment to the option -o of the command dvips:

dvips -o ...

and the completion function will generate filenames. Usually completion will be tried for all possible tags in an order given by the completion function. However, this can

be altered by using the tag-order style. Completion is then

restricted to the list of given tags in the given order.

The _complete_help bindable command shows all the contexts

and tags available for completion at a particular point. This provides an easy way of finding information for

tag-order and other styles. It is described in the section

`Bindable Commands' below.

Styles determine such things as how the matches are gen-

erated, similarly to shell options but with much more con-

trol. They can have any number of strings as their value.

They are defined with the zstyle builtin command (see zshmo-

dules(1)).

When looking up styles the completion system uses full con-

text names, including the tag. Looking up the value of a style therefore consists of two things: the context, which may be matched as a pattern, and the name of the style zsh 4.3.10 Last change: June 1, 2009 12 User Commands ZSHCOMPSYS(1) itself, which must be given exactly. For example, many completion functions can generate matches in a simple and a verbose form and use the verbose style to

decide which form should be used. To make all such func-

tions use the verbose form, put zstyle ':completion:*' verbose yes in a startup file (probably .zshrc). This gives the verbose style the value yes in every context inside the completion system, unless that context has a more specific definition. It is best to avoid giving the context as `*' in case the style has some meaning outside the completion system. Many such general purpose styles can be configured simply by using the compinstall function. A more specific example of the use of the verbose style is by the completion for the kill builtin. If the style is set, the builtin lists full job texts and process command lines; otherwise it shows the bare job numbers and PIDs. To turn the style off for this use only: zstyle ':completion:*:*:kill:*' verbose no For even more control, the style can use one of the tags `jobs' or `processes'. To turn off verbose display only for jobs: zstyle ':completion:*:*:kill:*:jobs' verbose no

The -e option to zstyle even allows completion function code

to appear as the argument to a style; this requires some understanding of the internals of completion functions (see see zshcompwid(1))). For example,

zstyle -e ':completion:*' hosts 'reply=($myhosts)'

This forces the value of the hosts style to be read from the variable myhosts each time a host name is needed; this is useful if the value of myhosts can change dynamically. For another useful example, see the example in the description

of the file-list style below. This form can be slow and

should be avoided for commonly examined styles such as menu

and list-rows-first.

Note that the order in which styles are defined does not matter; the style mechanism uses the most specific possible match for a particular style to determine the set of values. More precisely, strings are preferred over patterns (for example, `:completion::complete:foo' is more specific than zsh 4.3.10 Last change: June 1, 2009 13 User Commands ZSHCOMPSYS(1)

`:completion::complete:*'), and longer patterns are pre-

ferred over shorter patterns. Style names like those of tags are arbitrary and depend on

the completion function. However, the following two sec-

tions list some of the most common tags and styles. Standard Tags

Some of the following are only used when looking up particu-

lar styles and do not refer to a type of match. accounts

used to look up the users-hosts style

all-expansions

used by the _expand completer when adding the single

string containing all possible expansions

all-files

for the names of all files (as distinct from a particu-

lar subset, see the globbed-files tag).

arguments for arguments to a command arrays for names of array parameters

association-keys

for keys of associative arrays; used when completing inside a subscript to a parameter of this type bookmarks when completing bookmarks (e.g. for URLs and the zftp function suite) builtins for names of builtin commands characters for single characters in arguments of commands such as stty. Also used when completing character classes after an opening bracket colormapids for X colormap ids colors for color names commands for names of external commands. Also used by complex zsh 4.3.10 Last change: June 1, 2009 14 User Commands ZSHCOMPSYS(1) commands such as cvs when completing names subcommands. contexts for contexts in arguments to the zstyle builtin command corrections

used by the _approximate and _correct completers for

possible corrections cursors for cursor names used by X programs default used in some contexts to provide a way of supplying a default when more specific tags are also valid. Note that this tag is used when only the function field of the context name is set descriptions used when looking up the value of the format style to generate descriptions for types of matches devices for names of device special files directories for names of directories

directory-stack

for entries in the directory stack displays for X display names domains for network domains expansions

used by the _expand completer for individual words (as

opposed to the complete set of expansions) resulting from the expansion of a word on the command line extensions for X server extensions

file-descriptors

for numbers of open file descriptors files

the generic file-matching tag used by functions com-

pleting filenames zsh 4.3.10 Last change: June 1, 2009 15 User Commands ZSHCOMPSYS(1) fonts for X font names fstypes for file system types (e.g. for the mount command) functions

names of functions -- normally shell functions,

although certain commands may understand other kinds of function

globbed-files

for filenames when the name has been generated by pat-

tern matching groups for names of user groups

history-words

for words from the history hosts for hostnames indexes for array indexes jobs for jobs (as listed by the `jobs' builtin) interfaces for network interfaces keymaps for names of zsh keymaps keysyms for names of X keysyms libraries for names of system libraries limits for system limits

local-directories

for names of directories that are subdirectories of the current working directory when completing arguments of cd and related builtin commands (compare

path-directories)

manuals for names of manual pages zsh 4.3.10 Last change: June 1, 2009 16 User Commands ZSHCOMPSYS(1) mailboxes

for e-mail folders

maps for map names (e.g. NIS maps) messages used to look up the format style for messages modifiers for names of X modifiers modules for modules (e.g. zsh modules)

my-accounts

used to look up the users-hosts style

named-directories

for named directories (you wouldn't have guessed that, would you?) names for all kinds of names newsgroups for USENET groups nicknames for nicknames of NIS maps options for command options original

used by the _approximate, _correct and _expand com-

pleters when offering the original string as a match

other-accounts

used to look up the users-hosts style

other-files

for the names of any non-directory files. This is used

instead of all-files when the list-dirs-first style is

in effect. packages for packages (e.g. rpm or installed Debian packages) parameters for names of parameters

path-directories

zsh 4.3.10 Last change: June 1, 2009 17 User Commands ZSHCOMPSYS(1) for names of directories found by searching the cdpath

array when completing arguments of cd and related buil-

tin commands (compare local-directories)

paths used to look up the values of the expand, ambiguous and

special-dirs styles

pods for perl pods (documentation files) ports for communication ports prefixes for prefixes (like those of a URL) printers for print queue names processes for process identifiers

processes-names

used to look up the command style when generating the names of processes for killall sequences for sequences (e.g. mh sequences) sessions for sessions in the zftp function suite signals for signal names strings for strings (e.g. the replacement strings for the cd builtin command) styles for styles used by the zstyle builtin command suffixes for filename extensions tags for tags (e.g. rpm tags) targets for makefile targets

time-zones

for time zones (e.g. when setting the TZ parameter) zsh 4.3.10 Last change: June 1, 2009 18 User Commands ZSHCOMPSYS(1) types for types of whatever (e.g. address types for the xhost command)

urls used to look up the urls and local styles when complet-

ing URLs users for usernames values for one of a set of values in certain lists variant

used by _pick_variant to look up the command to run

when determining what program is installed for a par-

ticular command name. visuals for X visuals warnings used to look up the format style for warnings widgets for zsh widget names windows for IDs of X windows

zsh-options

for shell options Standard Styles Note that the values of several of these styles represent boolean values. Any of the strings `true', `on', `yes', and `1' can be used for the value `true' and any of the strings `false', `off', `no', and `0' for the value `false'. The behavior for any other value is undefined except where explicitly mentioned. The default value may be either true or false if the style is not set. Some of these styles are tested first for every possible tag corresponding to a type of match, and if no style was found, for the default tag. The most notable styles of this type

are menu, list-colors and styles controlling completion

listing such as list-packed and last-prompt). When tested

for the default tag, only the function field of the context

will be set so that a style using the default tag will nor-

mally be defined along the lines of: zsh 4.3.10 Last change: June 1, 2009 19 User Commands ZSHCOMPSYS(1) zstyle ':completion:*:default' menu ...

accept-exact

This is tested for the default tag in addition to the tags valid for the current context. If it is set to `true' and any of the trial matches is the same as the string on the command line, this match will immediately be accepted (even if it would otherwise be considered ambiguous). When completing pathnames (where the tag used is `paths') this style accepts any number of patterns as the value in addition to the boolean values. Pathnames

matching one of these patterns will be accepted immedi-

ately even if the command line contains some more par-

tially typed pathname components and these match no file under the directory accepted.

This style is also used by the _expand completer to

decide if words beginning with a tilde or parameter expansion should be expanded. For example, if there

are parameters foo and foobar, the string `$foo' will

only be expanded if accept-exact is set to `true'; oth-

erwise the completion system will be allowed to com-

plete $foo to $foobar. If the style is set to `con-

tinue', _expand will add the expansion as a match and

the completion system will also be allowed to continue.

accept-exact-dirs

This is used by filename completion. Unlike

accept-exact it is a boolean. By default, filename

completion examines all components of a path to see if there are completions of that component, even if the component matches an existing directory. For example, when completion after /usr/bin/, the function examines possible completions to /usr. When this style is true, any prefix of a path that matches an existing directory is accepted without any attempt to complete it further. Hence, in the given example, the path /usr/bin/ is accepted immediately and completion tried in that directory.

add-space

This style is used by the _expand completer. If it is

true (the default), a space will be inserted after all words resulting from the expansion, or a slash in the case of directory names. If the value is `file', the completer will only add a space to names of existing files. Either a boolean true or the value `file' may be combined with `subst', in which case the completer will not add a space to words generated from the zsh 4.3.10 Last change: June 1, 2009 20 User Commands ZSHCOMPSYS(1)

expansion of a substitution of the form `$(...)' or

`${...}'.

The _prefix completer uses this style as a simple

boolean value to decide if a space should be inserted before the suffix. ambiguous

This applies when completing non-final components of

filename paths, in other words those with a trailing slash. If it is set, the cursor is left after the first ambiguous component, even if menu completion is in use. The style is always tested with the paths tag.

assign-list

When completing after an equals sign that is being

treated as an assignment, the completion system nor-

mally completes only one filename. In some cases the value may be a list of filenames separated by colons, as with PATH and similar parameters. This style can be set to a list of patterns matching the names of such parameters. The default is to complete lists when the word on the line already contains a colon.

auto-description

If set, this style's value will be used as the descrip-

tion for options that are not described by the comple-

tion functions, but that have exactly one argument.

The sequence `%d' in the value will be replaced by the

description for this argument. Depending on personal preferences, it may be useful to set this style to

something like `specify: %d'. Note that this may not

work for some commands.

avoid-completer

This is used by the _all_matches completer to decide if

the string consisting of all matches should be added to the list currently being generated. Its value is a list of names of completers. If any of these is the name of the completer that generated the matches in this completion, the string will not be added.

The default value for this style is `_expand _old_list

_correct _approximate', i.e. it contains the completers

for which a string with all matches will almost never be wanted.

cache-path

This style defines the path where any cache files con-

taining dumped completion data are stored. It defaults zsh 4.3.10 Last change: June 1, 2009 21 User Commands ZSHCOMPSYS(1)

to `$ZDOTDIR/.zcompcache', or `$HOME/.zcompcache' if

$ZDOTDIR is not defined. The completion cache will not

be used unless the use-cache style is set.

cache-policy

This style defines the function that will be used to determine whether a cache needs rebuilding. See the

section on the _cache_invalid function below.

call-command

This style is used in the function for commands such as

make and ant where calling the command directly to gen-

erate matches suffers problems such as being slow or, as in the case of make can potentially causes actions in the makefile to be executed. If it is set to `true' the command is called to generate matches. The default value of this style is `false'. command In many places, completion functions need to call external commands to generate the list of completions. This style can be used to override the command that is called in some such cases. The elements of the value

are joined with spaces to form a command line to exe-

cute. The value can also start with a hyphen, in which case the usual command will be added to the end; this is most useful for putting `builtin' or `command' in front to make sure the appropriate version of a command

is called, for example to avoid calling a shell func-

tion with the same name as an external command. As an example, the completion function for process IDs uses this style with the processes tag to generate the IDs to complete and the list of processes to display (if the verbose style is `true'). The list produced by

the command should look like the output of the ps com-

mand. The first line is not displayed, but is searched for the string `PID' (or `pid') to find the position of the process IDs in the following lines. If the line does not contain `PID', the first numbers in each of

the other lines are taken as the process IDs to com-

plete. Note that the completion function generally has to call the specified command for each attempt to generate the completion list. Hence care should be taken to specify only commands that take a short time to run, and in particular to avoid any that may never terminate.

command-path

This is a list of directories to search for commands to complete. The default for this style is the value of zsh 4.3.10 Last change: June 1, 2009 22 User Commands ZSHCOMPSYS(1) the special parameter path. commands

This is used by the function completing sub-commands

for the system initialisation scripts (residing in /etc/init.d or somewhere not too far away from that). Its values give the default commands to complete for those commands for which the completion function isn't able to find them out automatically. The default for this style are the two strings `start' and `stop'. complete

This is used by the _expand_alias function when invoked

as a bindable command. If it set to `true' and the word on the command line is not the name of an alias, matching alias names will be completed.

complete-options

This is used by the completer for cd, chdir and pushd.

For these commands a - is used to introduce a directory

stack entry and completion of these is far more common than completing options. Hence unless the value of this style is true options will not be completed, even

after an initial -. If it is true, options will be

completed after an initial - unless there is a preced-

ing -- on the command line.

completer The strings given as the value of this style provide

the names of the completer functions to use. The avail-

able completer functions are described in the section `Control Functions' below.

Each string may be either the name of a completer func-

tion or a string of the form `function:name'. In the

first case the completer field of the context will con-

tain the name of the completer without the leading underscore and with all other underscores replaced by hyphens. In the second case the function is the name of the completer to call, but the context will contain

the user-defined name in the completer field of the

context. If the name starts with a hyphen, the string

for the context will be build from the name of the com-

pleter function as in the first case with the name appended to it. For example:

zstyle ':completion:*' completer _complete _complete:-foo

Here, completion will call the _complete completer

twice, once using `complete' and once using

`complete-foo' in the completer field of the context.

Normally, using the same completer more than once only zsh 4.3.10 Last change: June 1, 2009 23 User Commands ZSHCOMPSYS(1) makes sense when used with the `functions:name' form, because otherwise the context name will be the same in all calls to the completer; possible exceptions to this

rule are the _ignored and _prefix completers.

The default value for this style is `_complete

_ignored': only completion will be done, first using

the ignored-patterns style and the $fignore array and

then without ignoring matches. condition

This style is used by the _list completer function to

decide if insertion of matches should be delayed uncon-

ditionally. The default is `true'. delimiters This style is used when adding a delimiter for use with

history modifiers or glob qualifiers that have delim-

ited arguments. It is an array of preferred delimiters

to add. Non-special characters are preferred as the

completion system may otherwise become confused. The

default list is :, +, /, -, %. The list may be empty

to force a delimiter to be typed. disabled

If this is set to `true', the _expand_alias completer

and bindable command will try to expand disabled aliases, too. The default is `false'. domains A list of names of network domains for completion. If this is not set, domain names will be taken from the file /etc/resolv.conf. environ The environ style is used when completing for `sudo'. It is set to an array of `VAR=value' assignments to be

exported into the local environment before the comple-

tion for the target command is invoked. zstyle :complete:sudo: environ \

PATH="/sbin:/usr/sbin:$PATH" HOME="/root"

expand This style is used when completing strings consisting of multiple parts, such as path names.

If one of its values is the string `prefix', the par-

tially typed word from the line will be expanded as far as possible even if trailing parts cannot be completed. If one of its values is the string `suffix', matching names for components after the first ambiguous one will zsh 4.3.10 Last change: June 1, 2009 24 User Commands ZSHCOMPSYS(1) also be added. This means that the resulting string is the longest unambiguous string possible. However, menu completion can be used to cycle through all matches. fake This style may be set for any completion context. It

specifies additional strings that will always be com-

pleted in that context. The form of each string is `value:description'; the colon and description may be omitted, but any literal colons in value must be quoted with a backslash. Any description provided is shown alongside the value in completion listings.

It is important to use a sufficiently restrictive con-

text when specifying fake strings. Note that the

styles fake-files and fake-parameters provide addi-

tional features when completing files or parameters.

fake-always

This works identically to the fake style except that

the ignored-patterns style is not applied to it. This

makes it possible to override a set of matches com-

pletely by setting the ignored patterns to `*'. The following shows a way of supplementing any tag with

arbitrary data, but having it behave for display pur-

poses like a separate tag. In this example we use the

features of the tag-order style to divide the

named-directories tag into two when performing comple-

tion with the standard completer complete for arguments

of cd. The tag named-directories-normal behaves as

normal, but the tag named-directories-mine contains a

fixed set of directories. This has the effect of adding the match group `extra directories' with the given completions.

zstyle ':completion::complete:cd:*' tag-order \

'named-directories:-mine:extra\ directories

named-directories:-normal:named\ directories *'

zstyle ':completion::complete:cd:*:named-directories-mine' \

fake-always mydir1 mydir2

zstyle ':completion::complete:cd:*:named-directories-mine' \

ignored-patterns '*'

fake-files

This style is used when completing files and looked up without a tag. Its values are of the form `dir:names...'. This will add the names (strings

separated by spaces) as possible matches when complet-

ing in the directory dir, even if no such files really exist. The dir may be a pattern; pattern characters or colons in dir should be quote with a backslash to be treated literally. zsh 4.3.10 Last change: June 1, 2009 25 User Commands ZSHCOMPSYS(1) This can be useful on systems that support special

filesystems whose top-level pathnames can not be listed

or generated with glob patterns. It can also be used

for directories for which one does not have read per-

mission. The pattern form can be used to add a certain `magic' entry to all directories on a particular filing system.

fake-parameters

This is used by the completion function for parameter names. Its values are names of parameters that might not yet be set but should be completed nonetheless. Each name may also be followed by a colon and a string specifying the type of the parameter (like `scalar', `array' or `integer'). If the type is given, the name will only be completed if parameters of that type are required in the particular context. Names for which no type is specified will always be completed.

file-list

This style controls whether files completed using the standard builtin mechanism are to be listed with a long

list similar to ls -l. Note that this feature uses the

shell module zsh/stat for file information; this loads the builtin stat which will replace any external stat executable. To avoid this the following code can be included in an initialization file:

zmodload -i zsh/stat

disable stat The style may either be set to a true value (or `all'), or one of the values `insert' or `list', indicating

that files are to be listed in long format in all cir-

cumstances, or when attempting to insert a file name, or when listing file names without attempting to insert one. More generally, the value may be an array of any of the above values, optionally followed by =num. If num is present it gives the maximum number of matches for which long listing style will be used. For example,

zstyle ':completion:*' file-list list=20 insert=10

specifies that long format will be used when listing up to 20 files or inserting a file with up to 10 matches (assuming a listing is to be shown at all, for example on an ambiguous completion), else short format will be used. zsh 4.3.10 Last change: June 1, 2009 26 User Commands ZSHCOMPSYS(1)

zstyle -e ':completion:*' file-list '(( ${+NUMERIC} )) && reply=(true)'

specifies that long format will be used any time a numeric argument is supplied, else short format.

file-patterns

This is used by the standard function for completing

filenames, _files. If the style is unset up to three

tags are offered, `globbed-files',`directories' and

`all-files', depending on the types of files expected

by the caller of _files. The first two

(`globbed-files' and `directories') are normally

offered together to make it easier to complete files in

sub-directories.

The file-patterns style provides alternatives to the

default tags, which are not used. Its value consists of elements of the form `pattern:tag'; each string may contain any number of such specifications separated by spaces. The pattern is a pattern that is to be used to generate

filenames. Any occurrence of the sequence `%p' is

replaced by any pattern(s) passed by the function cal-

ling _files. Colons in the pattern must be preceded by

a backslash to make them distinguishable from the colon before the tag. If more than one pattern is needed, the patterns can be given inside braces, separated by commas. The tags of all strings in the value will be offered by

_files and used when looking up other styles. Any tags

in the same word will be offered at the same time and before later words. If no `:tag' is given the `files' tag will be used. The tag may also be followed by an optional second colon and a description, which will be used for the

`%d' in the value of the format style (if that is set)

instead of the default description supplied by the com-

pletion function. If the description given here con-

tains itself a `%d', that is replaced with the descrip-

tion supplied by the completion function. For example, to make the rm command first complete only names of object files and then the names of all files if there is no matching object file:

zstyle ':completion:*:*:rm:*' file-patterns \

'*.o:object-files' '%p:all-files'

zsh 4.3.10 Last change: June 1, 2009 27 User Commands ZSHCOMPSYS(1)

To alter the default behaviour of file completion --

offer files matching a pattern and directories on the

first attempt, then all files -- to offer only matching

files on the first attempt, then directories, and finally all files:

zstyle ':completion:*' file-patterns \

'%p:globbed-files' '*(-/):directories' '*:all-files'

This works even where there is no special pattern:

_files matches all files using the pattern `*' at the

first step and stops when it sees this pattern. Note also it will never try a pattern more than once for a single completion attempt. During the execution of completion functions, the

EXTENDED_GLOB option is in effect, so the characters

`#', `~' and `^' have special meanings in the patterns.

file-sort

The standard filename completion function uses this style without a tag to determine in which order the names should be listed; menu completion will cycle through them in the same order. The possible values are: `size' to sort by the size of the file; `links' to sort by the number of links to the file; `modification' (or `time' or `date') to sort by the last modification time; `access' to sort by the last access time; and `inode' (or `change') to sort by the last inode change time. If the style is set to any other value, or is unset, files will be sorted alphabetically by name. If the value contains the string `reverse', sorting is done in the opposite order. If the value contains the string `follow', timestamps are associated with the targets of symbolic links; the default is to use the timestamps of the links themselves. filter

This is used by the LDAP plugin for e-mail address com-

pletion to specify the attributes to match against when filtering entries. So for example, if the style is set to `sn', matching is done against surnames. Standard LDAP filtering is used so normal completion matching is bypassed. If this style is not set, the LDAP plugin is skipped. You may also need to set the command style to specify how to connect to your LDAP server.

force-list

This forces a list of completions to be shown at any point where listing is done, even in cases where the

list would usually be suppressed. For example, nor-

mally the list is only shown if there are at least two zsh 4.3.10 Last change: June 1, 2009 28 User Commands ZSHCOMPSYS(1) different matches. By setting this style to `always', the list will always be shown, even if there is only a single match that will immediately be accepted. The style may also be set to a number. In this case the list will be shown if there are at least that many matches, even if they would all insert the same string. This style is tested for the default tag as well as for each tag valid for the current completion. Hence the listing can be forced only for certain types of match. format If this is set for the descriptions tag, its value is used as a string to display above matches in completion

lists. The sequence `%d' in this string will be

replaced with a short description of what these matches are. This string may also contain the following sequences to specify output attributes, as described in the section EXPANSION OF PROMPT SEQUENCES in

zshmisc(1): `%B', `%S', `%U', `%F', `%K' and their

lower case counterparts, as well as `%{...%}'. `%F',

`%K' and `%{...%}' take arguments in the same form as

prompt expansion. Note that the %G sequence is not

available; an argument to `%{' should be used instead.

The style is tested with each tag valid for the current completion before it is tested for the descriptions tag. Hence different format strings can be defined for different types of match.

Note also that some completer functions define addi-

tional `%'-sequences. These are described for the com-

pleter functions that make use of them. Some completion functions display messages that may be customised by setting this style for the messages tag.

Here, the `%d' is replaced with a message given by the

completion function.

Finally, the format string is looked up with the warn-

ings tag, for use when no matches could be generated at

all. In this case the `%d' is replaced with the

descriptions for the matches that were expected

separated by spaces. The sequence `%D' is replaced

with the same descriptions separated by newlines.

It is possible to use printf-style field width specif-

iers with `%d' and similar escape sequences. This is

handled by the zformat builtin command from the zsh/zutil module, see zshmodules(1).

glob This is used by the _expand completer. If it is set to

zsh 4.3.10 Last change: June 1, 2009 29 User Commands ZSHCOMPSYS(1) `true' (the default), globbing will be attempted on the words resulting from a previous substitution (see the substitute style) or else the original string from the line. global If this is set to `true' (the default), the

_expand_alias completer and bindable command will try

to expand global aliases.

group-name

The completion system can group different types of matches, which appear in separate lists. This style can be used to give the names of groups for particular tags. For example, in command position the completion

system generates names of builtin and external com-

mands, names of aliases, shell functions and parameters and reserved words as possible completions. To have the external commands and shell functions listed separately:

zstyle ':completion:*:*:-command-:*:commands' group-name commands

zstyle ':completion:*:*:-command-:*:functions' group-name functions

As a consequence, any match with the same tag will be displayed in the same group. If the name given is the empty string the name of the tag for the matches will be used as the name of the group. So, to have all different types of matches displayed separately, one can just set:

zstyle ':completion:*' group-name ''

All matches for which no group name is defined will be

put in a group named -default-.

group-order

This style is additional to the group-name style to

specify the order for display of the groups defined by

that style (compare tag-order, which determines which

completions appear at all). The groups named are shown in the given order; any other groups are shown in the order defined by the completion function. For example, to have names of builtin commands, shell functions and external commands appear in that order when completing in command position:

zstyle ':completion:*:*:-command-:*' group-order \

builtins functions commands zsh 4.3.10 Last change: June 1, 2009 30 User Commands ZSHCOMPSYS(1) groups A list of names of UNIX groups. If this is not set, group names are taken from the YP database or the file `/etc/group'. hidden If this is set to true, matches for the given context will not be listed, although any description for the matches set with the format style will be shown. If it is set to `all', not even the description will be displayed. Note that the matches will still be completed; they are just not shown in the list. To avoid having matches considered as possible completions at all, the

tag-order style can be modified as described below.

hosts A list of names of hosts that should be completed. If this is not set, hostnames are taken from the file `/etc/hosts'.

hosts-ports

This style is used by commands that need or accept hostnames and network ports. The strings in the value should be of the form `host:port'. Valid ports are determined by the presence of hostnames; multiple ports for the same host may appear.

ignore-line

This is tested for each tag valid for the current com-

pletion. If it is set to `true', none of the words

that are already on the line will be considered as pos-

sible completions. If it is set to `current', the word the cursor is on will not be considered as a possible

completion. The value `current-shown' is similar but

only applies if the list of completions is currently shown on the screen. Finally, if the style is set to `other', no word apart from the current one will be considered as a possible completion.

The values `current' and `current-shown' are a bit like

the opposite of the accept-exact style: only strings

with missing characters will be completed. Note that you almost certainly don't want to set this to `true' or `other' for a general context such as `:completion:*'. This is because it would disallow completion of, for example, options multiple times even if the command in question accepts the option more than once. zsh 4.3.10 Last change: June 1, 2009 31 User Commands ZSHCOMPSYS(1)

ignore-parents

The style is tested without a tag by the function com-

pleting pathnames in order to determine whether to ignore the names of directories already mentioned in the current word, or the name of the current working directory. The value must include one or both of the following strings: parent The name of any directory whose path is already contained in the word on the line is ignored. For

example, when completing after foo/../, the direc-

tory foo will not be considered a valid comple-

tion. pwd The name of the current working directory will not be completed; hence, for example, completion after

../ will not use the name of the current direc-

tory. In addition, the value may include one or both of: .. Ignore the specified directories only when the word on the line contains the substring `../'. directory Ignore the specified directories only when names of directories are completed, not when completing names of files. Excluded values act in a similar fashion to values of

the ignored-patterns style, so they can be restored to

consideration by the _ignored completer.

extra-verbose

If set, the completion listing is more verbose at the

cost of a probable decrease in completion speed. Com-

pletion performance will suffer if this style is set to `true'.

ignored-patterns

A list of patterns; any trial completion matching one of the patterns will be excluded from consideration.

The _ignored completer can appear in the list of com-

pleters to restore the ignored matches. This is a more

configurable version of the shell parameter $fignore.

Note that the EXTENDED_GLOB option is set during the

execution of completion functions, so the characters

`#', `~' and `^' have special meanings in the patterns.

insert zsh 4.3.10 Last change: June 1, 2009 32 User Commands ZSHCOMPSYS(1)

This style is used by the _all_matches completer to

decide whether to insert the list of all matches uncon-

ditionally instead of adding the list as another match.

insert-ids

When completing process IDs, for example as arguments to the kill and wait builtins the name of a command may be converted to the appropriate process ID. A problem arises when the process name typed is not unique. By default (or if this style is set explicitly to `menu')

the name will be converted immediately to a set of pos-

sible IDs, and menu completion will be started to cycle through them. If the value of the style is `single', the shell will

wait until the user has typed enough to make the com-

mand unique before converting the name to an ID; attempts at completion will be unsuccessful until that

point. If the value is any other string, menu comple-

tion will be started when the string typed by the user is longer than the common prefix to the corresponding IDs.

insert-tab

If this is set to `true', the completion system will insert a TAB character (assuming that was used to start completion) instead of performing completion when there

is no non-blank character to the left of the cursor.

If it is set to `false', completion will be done even there. The value may also contain the substrings `pending' or `pending=val'. In this case, the typed character will be inserted instead of staring completion when there is

unprocessed input pending. If a val is given, comple-

tion will not be done if there are at least that many characters of unprocessed input. This is often useful when pasting characters into a terminal. Note however,

that it relies on the $PENDING special parameter from

the zsh/zle module being set properly which is not guaranteed on all platforms. The default value of this style is `true' except for completion within vared builtin command where it is `false'.

insert-unambiguous

This is used by the _match and _approximate completers.

These completers are often used with menu completion since the word typed may bear little resemblance to the final completion. However, if this style is `true', the completer will start menu completion only if it zsh 4.3.10 Last change: June 1, 2009 33 User Commands ZSHCOMPSYS(1) could find no unambiguous initial string at least as long as the original string typed by the user.

In the case of the _approximate completer, the com-

pleter field in the context will already have been set

to one of correct-num or approximate-num, where num is

the number of errors that were accepted.

In the case of the _match completer, the style may also

be set to the string `pattern'. Then the pattern on

the line is left unchanged if it does not match unambi-

guously.

keep-prefix

This style is used by the _expand completer. If it is

`true', the completer will try to keep a prefix con-

taining a tilde or parameter expansion. Hence, for example, the string `~/f*' would be expanded to `~/foo' instead of `/home/user/foo'. If the style is set to `changed' (the default), the prefix will only be left unchanged if there were other changes between the expanded words and the original word from the command line. Any other value forces the prefix to be expanded unconditionally. The behaviour of expand when this style is true is to

cause _expand to give up when a single expansion with

the restored prefix is the same as the original; hence any remaining completers may be called.

last-prompt

This is a more flexible form of the ALWAYS_LAST_PROMPT

option. If it is true, the completion system will try to return the cursor to the previous command line after displaying a completion list. It is tested for all tags valid for the current completion, then the default tag. The cursor will be moved back to the previous line if this style is `true' for all types of match.

Note that unlike the ALWAYS_LAST_PROMPT option this is

independent of the numeric prefix argument.

known-hosts-files

This style should contain a list of files to search for

host names and (if the use-ip style is set) IP

addresses in a format compatible with ssh known_hosts

files. If it is not set, the files

/etc/ssh/ssh_known_hosts and ~/.ssh/known_hosts are

used.

list This style is used by the _history_complete_word bind-

able command. If it is set to `true' it has no effect. If it is set to `false' matches will not be listed. zsh 4.3.10 Last change: June 1, 2009 34 User Commands ZSHCOMPSYS(1) This overrides the setting of the options controlling

listing behaviour, in particular AUTO_LIST. The con-

text always starts with `:completion:history-words'.

list-colors

If the zsh/complist module is loaded, this style can be used to set color specifications. This mechanism

replaces the use of the ZLS_COLORS and ZLS_COLOURS

parameters described in the section `The zsh/complist Module' in zshmodules(1), but the syntax is the same. If this style is set for the default tag, the strings in the value are taken as specifications that are to be used everywhere. If it is set for other tags, the specifications are used only for matches of the type described by the tag. For this to work best, the

group-name style must be set to an empty string.

In addition to setting styles for specific tags, it is also possible to use group names specified explicitly

by the group-name tag together with the `(group)' syn-

tax allowed by the ZLS_COLORS and ZLS_COLOURS parame-

ters and simply using the default tag. It is possible to use any color specifications already set up for the GNU version of the ls command:

zstyle ':completion:*:default' list-colors ${(s.:.)LS_COLORS}

The default colors are the same as for the GNU ls com-

mand and can be obtained by setting the style to an empty string (i.e. '').

list-dirs-first

This is used by file completion. If set, directories to be completed are listed separately from and before completion for other files, regardless of tag ordering.

In addition, the tag other-files is used in place of

all-files for the remaining files, to indicate that no

directories are presented with that tag.

list-grouped

If this style is `true' (the default), the completion system will try to make certain completion listings more compact by grouping matches. For example, options for commands that have the same description (shown when the verbose style is set to `true') will appear as a single entry. However, menu selection can be used to cycle through all the matches.

list-packed

This is tested for each tag valid in the current zsh 4.3.10 Last change: June 1, 2009 35 User Commands ZSHCOMPSYS(1) context as well as the default tag. If it is set to `true', the corresponding matches appear in listings as

if the LIST_PACKED option were set. If it is set to

`false', they are listed normally.

list-prompt

If this style is set for the default tag, completion lists that don't fit on the screen can be scrolled (see

the description of the zsh/complist module in zshmo-

dules(1)). The value, if not the empty string, will be displayed after every screenful and the shell will prompt for a key press; if the style is set to the empty string, a default prompt will be used.

The value may contain the escape sequences: `%l' or

`%L', which will be replaced by the number of the last

line displayed and the total number of lines; `%m' or

`%M', the number of the last match shown and the total

number of matches; and `%p' and `%P', `Top' when at the

beginning of the list, `Bottom' when at the end and the

position shown as a percentage of the total length oth-

erwise. In each case the form with the uppercase letter will be replaced by a string of fixed width, padded to the right with spaces, while the lowercase form will be replaced by a variable width string. As

in other prompt strings, the escape sequences `%S',

`%s', `%B', `%b', `%U', `%u' for entering and leaving

the display modes standout, bold and underline, and

`%F', `%f', `%K', `%k' for changing the foreground

background colour, are also available, as is the form

`%{...%}' for enclosing escape sequences which display

with zero (or, with a numeric argument, some other) width. After deleting this prompt the variable LISTPROMPT should be unset for the the removal to take effect.

list-rows-first

This style is tested in the same way as the list-packed

style and determines whether matches are to be listed

in a rows-first fashion as if the LIST_ROWS_FIRST

option were set.

list-suffixes

This style is used by the function that completes filenames. If it is true, and completion is attempted

on a string containing multiple partially typed path-

name components, all ambiguous components will be

shown. Otherwise, completion stops at the first ambi-

guous component.

list-separator

zsh 4.3.10 Last change: June 1, 2009 36 User Commands ZSHCOMPSYS(1) The value of this style is used in completion listing to separate the string to complete from a description when possible (e.g. when completing options). It

defaults to `--' (two hyphens).

local This is for use with functions that complete URLs for which the corresponding files are available directly from the filing system. Its value should consist of three strings: a hostname, the path to the default web pages for the server, and the directory name used by a user placing web pages within their home area. For example: zstyle ':completion:*' local toast \

/var/http/public/toast public_html

Completion after `http://toast/stuff/' will look for files in the directory /var/http/public/toast/stuff, while completion after `http://toast/~yousir/' will

look for files in the directory ~yousir/public_html.

mail-directory

If set, zsh will assume that mailbox files can be found

in the directory specified. It defaults to `~/Mail'.

match-original

This is used by the _match completer. If it is set to

only, _match will try to generate matches without

inserting a `*' at the cursor position. If set to any

other non-empty value, it will first try to generate

matches without inserting the `*' and if that yields no matches, it will try again with the `*' inserted. If it is unset or set to the empty string, matching will only be performed with the `*' inserted. matcher This style is tested separately for each tag valid in the current context. Its value is added to any match

specifications given by the matcher-list style. It

should be in the form described in the section `Comple-

tion Matching Control' in zshcompwid(1).

matcher-list

This style can be set to a list of match specifications that are to be applied everywhere. Match specifications

are described in the section `Completion Matching Con-

trol' in zshcompwid(1). The completion system will try them one after another for each completer selected. For example, to try first simple completion and, if

that generates no matches, case-insensitive completion:

zsh 4.3.10 Last change: June 1, 2009 37 User Commands ZSHCOMPSYS(1)

zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'

By default each specification replaces the previous one; however, if a specification is prefixed with +, it is added to the existing list. Hence it is possible to create increasingly general specifications without repetition:

zstyle ':completion:*' matcher-list '' '+m{a-Z}={A-Z}' '+m{A-Z}={a-z}'

It is possible to create match specifications valid for particular completers by using the third field of the

context. For example, to use the completers _complete

and _prefix but only allow case-insensitive completion

with _complete:

zstyle ':completion:*' completer _complete _prefix

zstyle ':completion:*:complete:*' matcher-list \

'' 'm:{a-zA-Z}={A-Za-z}'

User-defined names, as explained for the completer

style, are available. This makes it possible to try the same completer more than once with different match specifications each time. For example, to try normal completion without a match specification, then normal

completion with case-insensitive matching, then correc-

tion, and finally partial-word completion:

zstyle ':completion:*' completer _complete _correct _complete:foo

zstyle ':completion:*:complete:*' matcher-list \

'' 'm:{a-zA-Z}={A-Za-z}'

zstyle ':completion:*:foo:*' matcher-list \

'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'

If the style is unset in any context no match specifi-

cation is applied. Note also that some completers such

as _correct and _approximate do not use the match

specifications at all, though these completers will

only ever called once even if the matcher-list contains

more than one element. Where multiple specifications are useful, note that the entire completion is done for each element of

matcher-list, which can quickly reduce the shell's per-

formance. As a rough rule of thumb, one to three strings will give acceptable performance. On the other

hand, putting multiple space-separated values into the

same string does not have an appreciable impact on per-

formance. If there is no current matcher or it is empty, and the

option NO_CASE_GLOB is in effect, the matching for

zsh 4.3.10 Last change: June 1, 2009 38 User Commands ZSHCOMPSYS(1)

files is performed case-insensitively in any case.

However, any matcher must explicitly specify

case-insensitive matching if that is required.

max-errors

This is used by the _approximate and _correct completer

functions to determine the maximum number of errors to allow. The completer will try to generate completions by first allowing one error, then two errors, and so on, until either a match or matches were found or the maximum number of errors given by this style has been reached. If the value for this style contains the string `numeric', the completer function will take any numeric argument as the maximum number of errors allowed. For example, with

zstyle ':completion:*:approximate:::' max-errors 2 numeric

two errors are allowed if no numeric argument is given,

but with a numeric argument of six (as in `ESC-6 TAB'),

up to six errors are accepted. Hence with a value of `0 numeric', no correcting completion will be attempted unless a numeric argument is given.

If the value contains the string `not-numeric', the

completer will not try to generate corrected comple-

tions when given a numeric argument, so in this case the number given should be greater than zero. For

example, `2 not-numeric' specifies that correcting com-

pletion with two errors will usually be performed, but if a numeric argument is given, correcting completion will not be performed. The default value for this style is `2 numeric'.

max-matches-width

This style is used to determine the trade off between the width of the display used for matches and the width used for their descriptions when the verbose style is in effect. The value gives the number of display columns to reserve for the matches. The default is half the width of the screen. This has the most impact when several matches have the same description and so will be grouped together. Increasing the style will allow more matches to be grouped together; decreasing it will allow more of the description to be visible. menu If this is true in the context of any of the tags zsh 4.3.10 Last change: June 1, 2009 39 User Commands ZSHCOMPSYS(1) defined for the current completion menu completion will

be used. The value for a specific tag will take pre-

cedence over that for the `default' tag. If none of the values found in this way is true but at least one is set to `auto', the shell behaves as if the

AUTO_MENU option is set.

If one of the values is explicitly set to false, menu completion will be explicitly turned off, overriding

the MENU_COMPLETE option and other settings.

In the form `yes=num', where `yes' may be any of the

true values (`yes', `true', `on' and `1'), menu comple-

tion will be turned on if there are at least num matches. In the form `yes=long', menu completion will be turned on if the list does not fit on the screen. This does not activate menu completion if the widget normally only lists completions, but menu completion can be activated in that case with the value

`yes=long-list' (Typically, the value

`select=long-list' described later is more useful as it

provides control over scrolling.) Similarly, with any of the `false' values (as in `no=10'), menu completion will not be used if there are num or more matches. The value of this widget also controls menu selection,

as implemented by the zsh/complist module. The follow-

ing values may appear either alongside or instead of the values above.

If the value contains the string `select', menu selec-

tion will be started unconditionally. In the form `select=num', menu selection will only be started if there are at least num matches. If the values for more than one tag provide a number, the smallest number is taken. Menu selection can be turned off explicitly by defining

a value containing the string`no-select'.

It is also possible to start menu selection only if the list of matches does not fit on the screen by using the value `select=long'. To start menu selection even if the current widget only performs listing, use the value

`select=long-list'.

To turn on menu completion or menu selection when a there are a certain number of matches or the list of zsh 4.3.10 Last change: June 1, 2009 40 User Commands ZSHCOMPSYS(1) matches does not fit on the screen, both of `yes=' and `select=' may be given twice, once with a number and

once with `long' or `long-list'.

Finally, it is possible to activate two special modes of menu selection. The word `interactive' in the value causes interactive mode to be entered immediately when menu selection is started; see the description of the zsh/complist module in zshmodules(1) for a description of interactive mode. Including the string `search' does the same for incremental search mode. To select backward incremental search, include the string

`search-backward'.

muttrc If set, gives the location of the mutt configuration file. It defaults to `~/.muttrc'. numbers This is used with the jobs tag. If it is `true', the shell will complete job numbers instead of the shortest unambiguous prefix of the job command text. If the value is a number, job numbers will only be used if that many words from the job descriptions are required to resolve ambiguities. For example, if the value is `1', strings will only be used if all jobs differ in the first word on their command lines.

old-list

This is used by the _oldlist completer. If it is set

to `always', then standard widgets which perform list-

ing will retain the current list of matches, however they were generated; this can be turned off explicitly with the value `never', giving the behaviour without

the _oldlist completer. If the style is unset, or any

other value, then the existing list of completions is displayed if it is not already; otherwise, the standard completion list is generated; this is the default

behaviour of _oldlist. However, if there is an old

list and this style contains the name of the completer function that generated the list, then the old list will be used even if it was generated by a widget which does not do listing. For example, suppose you type ^Xc to use the

_correct_word widget, which generates a list of correc-

tions for the word under the cursor. Usually, typing ^D would generate a standard list of completions for the word on the command line, and show that. With

_oldlist, it will instead show the list of corrections

already generated. zsh 4.3.10 Last change: June 1, 2009 41 User Commands ZSHCOMPSYS(1)

As another example consider the _match completer: with

the insert-unambiguous style set to `true' it inserts

only a common prefix string, if there is any. However, this may remove parts of the original pattern, so that further completion could produce more matches than on

the first attempt. By using the _oldlist completer and

setting this style to _match, the list of matches gen-

erated on the first attempt will be used again.

old-matches

This is used by the _all_matches completer to decide if

an old list of matches should be used if one exists. This is selected by one of the `true' values or by the

string `only'. If the value is `only', _all_matches

will only use an old list and won't have any effect on the list of matches currently being generated. If this style is set it is generally unwise to call the

_all_matches completer unconditionally. One possible

use is for either this style or the completer style to

be defined with the -e option to zstyle to make the

style conditional.

old-menu

This is used by the _oldlist completer. It controls

how menu completion behaves when a completion has already been inserted and the user types a standard completion key such as TAB. The default behaviour of

_oldlist is that menu completion always continues with

the existing list of completions. If this style is set to `false', however, a new completion is started if the

old list was generated by a different completion com-

mand; this is the behaviour without the _oldlist com-

pleter. For example, suppose you type ^Xc to generate a list of corrections, and menu completion is started in one of the usual ways. Usually, or with this style set to false, typing TAB at this point would start trying to

complete the line as it now appears. With _oldlist, it

instead continues to cycle through the list of correc-

tions. original

This is used by the _approximate and _correct com-

pleters to decide if the original string should be added as a possible completion. Normally, this is done only if there are at least two possible corrections, but if this style is set to `true', it is always added. Note that the style will be examined with the completer

field in the context name set to correct-num or

approximate-num, where num is the number of errors that

zsh 4.3.10 Last change: June 1, 2009 42 User Commands ZSHCOMPSYS(1) were accepted. packageset This style is used when completing arguments of the Debian `dpkg' program. It contains an override for the default package set for a given context. For example,

zstyle ':completion:*:complete:dpkg:option--status-1:*' \

packageset avail causes available packages, rather than only installed

packages, to be completed for `dpkg --status'.

path The function that completes color names uses this style with the colors tag. The value should be the pathname of a file containing color names in the format of an X11 rgb.txt file. If the style is not set but this file is found in one of various standard locations it will be used as the default.

pine-directory

If set, specifies the directory containing PINE mailbox

files. There is no default, since recursively search-

ing this directory is inconvenient for anyone who doesn't use PINE. ports A list of Internet service names (network ports) to complete. If this is not set, service names are taken from the file `/etc/services'.

prefix-hidden

This is used for certain completions which share a com-

mon prefix, for example command options beginning with dashes. If it is `true', the prefix will not be shown in the list of matches. The default value for this style is `false'.

prefix-needed

This, too, is used for matches with a common prefix. If it is set to `true' this common prefix must be typed by the user to generate the matches. In the case of

command options, this means that the initial `-', `+',

or `--' must be typed explicitly before option names

will be completed. The default value for this style is `true'.

preserve-prefix

This style is used when completing path names. Its value should be a pattern matching an initial prefix of zsh 4.3.10 Last change: June 1, 2009 43 User Commands ZSHCOMPSYS(1) the word to complete that should be left unchanged under all circumstances. For example, on some Unices an initial `//' (double slash) has a special meaning; setting this style to the string `//' will preserve it. As another example, setting this style to `?:/' under Cygwin would allow completion after `a:/...' and so on. range

This is used by the _history completer and the

_history_complete_word bindable command to decide which

words should be completed. If it is a singe number, only the last N words from the history will be completed. If it is a range of the form `max:slice', the last slice words will be completed; then if that yields no matches, the slice words before those will be tried and so on. This process stops either when at least one match was been found, or max words have been tried. The default is to complete all words from the history at once. regular

This style is used by the _expand_alias completer and

bindable command. If set to `true' (the default), reg-

ular aliases will be expanded but only in command posi-

tion. If it is set to `false', regular aliases will never be expanded. If it is set to `always', regular

aliases will be expanded even if not in command posi-

tion. rehash If this is set when completing external commands, the internal list (hash) of commands will be updated for each search by issuing the rehash command. There is a speed penalty for this which is only likely to be noticeable when directories in the path have slow file access.

remote-access

If set to false, certain commands will be prevented from making Internet connections to retrieve remote information. This includes the completion for the CVS command. It is not always possible to know if connections are in fact to a remote site, so some may be prevented unnecessarily.

remove-all-dups

zsh 4.3.10 Last change: June 1, 2009 44 User Commands ZSHCOMPSYS(1)

The _history_complete_word bindable command and the

_history completer use this to decide if all duplicate

matches should be removed, rather than just consecutive duplicates.

select-prompt

If this is set for the default tag, its value will be displayed during menu selection (see the menu style above) when the completion list does not fit on the screen as a whole. The same escapes as for the

list-prompt style are understood, except that the

numbers refer to the match or line the mark is on. A default prompt is used when the value is the empty string.

select-scroll

This style is tested for the default tag and determines

how a completion list is scrolled during a menu selec-

tion (see the menu style above) when the completion list does not fit on the screen as a whole. If the value is `0' (zero), the list is scrolled by

half-screenfuls; if it is a positive integer, the list

is scrolled by the given number of lines; if it is a negative number, the list is scrolled by a screenful minus the absolute value of the given number of lines. The default is to scroll by single lines.

separate-sections

This style is used with the manuals tag when completing names of manual pages. If it is `true', entries for different sections are added separately using tag names of the form `manual.X', where X is the section number.

When the group-name style is also in effect, pages from

different sections will appear separately. This style

is also used similarly with the words style when com-

pleting words for the dict command. It allows words from different dictionary databases to be added separately. The default for this style is `false'.

show-completer

Tested whenever a new completer is tried. If it is true, the completion system outputs a progress message in the listing area showing what completer is being tried. The message will be overwritten by any output

when completions are found and is removed after comple-

tion is finished.

single-ignored

This is used by the _ignored completer when there is

only one match. If its value is `show', the single match will be displayed but not inserted. If the value is `menu', then the single match and the original zsh 4.3.10 Last change: June 1, 2009 45 User Commands ZSHCOMPSYS(1) string are both added as matches and menu completion is started, making it easy to select either of them.

sort Many completion widgets call _description at some point

which decides whether the matches are added sorted or

unsorted (often indirectly via _wanted or _requested).

This style can be set explicitly to one of the usual true or false values as an override. If it is not set for the context, the standard behaviour of the calling widget is used. The style is tested first against the full context including the tag, and if that fails to produce a value against the context without the tag. If the calling widget explicitly requests unsorted matches, this is usually honoured. However, the

default (unsorted) behaviour of completion for the com-

mand history may be overridden by setting the style to true.

In the _expand completer, if it is set to `true', the

expansions generated will always be sorted. If it is set to `menu', then the expansions are only sorted when they are offered as single strings but not in the string containing all possible expansions.

special-dirs

Normally, the completion code will not produce the directory names `.' and `..' as possible completions. If this style is set to `true', it will add both `.' and `..' as possible completions; if it is set to `..', only `..' will be added.

The following example sets special-dirs to `..' when

the current prefix is empty, is a single `.', or con-

sists only of a path beginning with `../'. Otherwise the value is `false'.

zstyle -e ':completion:*' special-dirs \

'[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'

squeeze-slashes

If set to `true', sequences of slashes in filename paths (for example in `foo//bar') will be treated as a single slash. This is the usual behaviour of UNIX

paths. However, by default the file completion func-

tion behaves as if there were a `*' between the slashes.

stop If set to `true', the _history_complete_word bindable

command will stop once when reaching the beginning or zsh 4.3.10 Last change: June 1, 2009 46 User Commands ZSHCOMPSYS(1)

end of the history. Invoking _history_complete_word

will then wrap around to the opposite end of the his-

tory. If this style is set to `false' (the default),

_history_complete_word will loop immediately as in a

menu completion.

strip-comments

If set to `true', this style causes non-essential com-

ment text to be removed from completion matches.

Currently it is only used when completing e-mail

addresses where it removes any display name from the addresses, cutting them down to plain user@host form.

subst-globs-only

This is used by the _expand completer. If it is set to

`true', the expansion will only be used if it resulted from globbing; hence, if expansions resulted from the use of the substitute style described below, but these were not further changed by globbing, the expansions will be rejected. The default for this style is `false'. substitute

This boolean style controls whether the _expand com-

pleter will first try to expand all substitutions in

the string (such as `$(...)' and `${...}').

The default is `true'. suffix

This is used by the _expand completer if the word

starts with a tilde or contains a parameter expansion. If it is set to `true', the word will only be expanded if it doesn't have a suffix, i.e. if it is something

like `~foo' or `$foo' rather than `~foo/' or

`$foo/bar', unless that suffix itself contains charac-

ters eligible for expansion. The default for this style is `true'.

tag-order

This provides a mechanism for sorting how the tags available in a particular context will be used.

The values for the style are sets of space-separated

lists of tags. The tags in each value will be tried at the same time; if no match is found, the next value is

used. (See the file-patterns style for an exception to

this behavior.) For example: zsh 4.3.10 Last change: June 1, 2009 47 User Commands ZSHCOMPSYS(1)

zstyle ':completion:*:complete:-command-:*' tag-order \

'commands functions' specifies that completion in command position first

offers external commands and shell functions. Remain-

ing tags will be tried if no completions are found. In addition to tag names, each string in the value may take one of the following forms:

- If any value consists of only a hyphen, then only

the tags specified in the other values are gen-

erated. Normally all tags not explicitly selected

are tried last if the specified tags fail to gen-

erate any matches. This means that a single value

consisting only of a single hyphen turns off com-

pletion. ! tags...

A string starting with an exclamation mark speci-

fies names of tags that are not to be used. The effect is the same as if all other possible tags for the context had been listed. tag:label ... Here, tag is one of the standard tags and label is

an arbitrary name. Matches are generated as nor-

mal but the name label is used in contexts instead of tag. This is not useful in words starting with !. If the label starts with a hyphen, the tag is prepended to the label to form the name used for lookup. This can be used to make the completion system try a certain tag more than once, supplying different style settings for each attempt; see below for an example. tag:label:description

As before, but description will replace the `%d'

in the value of the format style instead of the default description supplied by the completion function. Spaces in the description must be

quoted with a backslash. A `%d' appearing in

description is replaced with the description given by the completion function. In any of the forms above the tag may be a pattern or several patterns in the form `{pat1,pat2...}'. In this case all matching tags will be used except for any given explicitly in the same string. zsh 4.3.10 Last change: June 1, 2009 48 User Commands ZSHCOMPSYS(1) One use of these features is to try one tag more than once, setting other styles differently on each attempt, but still to use all the other tags without having to repeat them all. For example, to make completion of

function names in command position ignore all the com-

pletion functions starting with an underscore the first time completion is tried:

zstyle ':completion:*:*:-command-:*' tag-order \

'functions:-non-comp *' functions

zstyle ':completion:*:functions-non-comp' ignored-patterns '_*'

On the first attempt, all tags will be offered but the

functions tag will be replaced by functions-non-comp.

The ignored-patterns style is set for this tag to

exclude functions starting with an underscore. If

there are no matches, the second value of the tag-order

style is used which completes functions using the

default tag, this time presumably including all func-

tion names. The matches for one tag can be split into different groups. For example:

zstyle ':completion:*' tag-order \

'options:-long:long\ options

options:-short:short\ options

options:-single-letter:single\ letter\ options'

zstyle ':completion:*:options-long' ignored-patterns '[-+](|-|[^-]*)'

zstyle ':completion:*:options-short' ignored-patterns '--*' '[-+]?'

zstyle ':completion:*:options-single-letter' ignored-patterns '???*'

With the group-names style set, options beginning with

`--', options beginning with a single `-' or `+' but

containing multiple characters, and single-letter

options will be displayed in separate groups with dif-

ferent descriptions. Another use of patterns is to try multiple match

specifications one after another. The matcher-list

style offers something similar, but it is tested very early in the completion system and hence can't be set for single commands nor for more specific contexts. Here is how to try normal completion without any match specification and, if that generates no matches, try

again with case-insensitive matching, restricting the

effect to arguments of the command foo:

zstyle ':completion:*:*:foo:*' tag-order '*' '*:-case'

zstyle ':completion:*-case' matcher 'm:{a-z}={A-Z}'

zsh 4.3.10 Last change: June 1, 2009 49 User Commands ZSHCOMPSYS(1) First, all the tags offered when completing after foo are tried using the normal tag name. If that generates

no matches, the second value of tag-order is used,

which tries all tags again except that this time each

has -case appended to its name for lookup of styles.

Hence this time the value for the matcher style from the second call to zstyle in the example is used to

make completion case-insensitive.

It is possible to use the -e option of the zstyle buil-

tin command to specify conditions for the use of par-

ticular tags. For example:

zstyle -e '*:-command-:*' tag-order '

if [[ -n $PREFIX$SUFFIX ]]; then

reply=( ) else

reply=( - )

fi' Completion in command position will be attempted only if the string typed so far is not empty. This is tested using the PREFIX special parameter; see zshcompwid for a description of parameters which are special inside completion widgets. Setting reply to an empty array provides the default behaviour of trying all tags at once; setting it to an array containing only a hyphen disables the use of all tags and hence of all completions.

If no tag-order style has been defined for a context,

the strings `(|*-)argument-* (|*-)option-* values' and

`options' plus all tags offered by the completion func-

tion will be used to provide a sensible default behavior that causes arguments (whether normal command arguments or arguments of options) to be completed before option names for most commands.

urls This is used together with the the urls tag by func-

tions completing URLs. If the value consists of more than one string, or if the only string does not name a file or directory, the strings are used as the URLs to complete. If the value contains only one string which is the name of a normal file the URLs are taken from that file

(where the URLs may be separated by white space or new-

lines).

Finally, if the only string in the value names a direc-

tory, the directory hierarchy rooted at this directory zsh 4.3.10 Last change: June 1, 2009 50 User Commands ZSHCOMPSYS(1) gives the completions. The top level directory should be the file access method, such as `http', `ftp', `bookmark' and so on. In many cases the next level of

directories will be a filename. The directory hierar-

chy can descend as deep as necessary. For example, zstyle ':completion:*' urls ~/.urls

mkdir -p ~/.urls/ftp/ftp.zsh.org/pub/development

allows completion of all the components of the URL

ftp://ftp.zsh.org/pub/development after suitable com-

mands such as `netscape' or `lynx'. Note, however, that access methods and files are completed separately, so if the hosts style is set hosts can be completed without reference to the urls style.

See the description in the function _urls itself for

more information (e.g. `more $^fpath/_urls(N)').

use-cache

If this is set, the completion caching layer is activated for any completions which use it (via the

_store_cache, _retrieve_cache, and _cache_invalid func-

tions). The directory containing the cache files can

be changed with the cache-path style.

use-compctl

If this style is set to a string not equal to false, 0,

no, and off, the completion system may use any comple-

tion specifications defined with the compctl builtin command. If the style is unset, this is done only if the zsh/compctl module is loaded. The string may also contain the substring `first' to use completions

defined with `compctl -T', and the substring `default'

to use the completion defined with `compctl -D'.

Note that this is only intended to smooth the transi-

tion from compctl to the new completion system and may disappear in the future. Note also that the definitions from compctl will only be used if there is no specific completion function for the command in question. For example, if there is a

function _foo to complete arguments to the command foo,

compctl will never be invoked for foo. However, the compctl version will be tried if foo only uses default completion.

use-ip

zsh 4.3.10 Last change: June 1, 2009 51 User Commands ZSHCOMPSYS(1)

By default, the function _hosts that completes host

names strips IP addresses from entries read from host databases such as NIS and ssh files. If this style is true, the corresponding IP addresses can be completed as well. This style is not use in any context where the hosts style is set; note also it must be set before the cache of host names is generated (typically the first completion attempt).

use-perl

Various parts of the function system use awk to extract words from files or command output as this universally

available. However, many versions of awk have arbi-

trary limits on the size of input. If this style is set, perl will be used instead. This is almost always preferable if perl is available on your system. Currently this is only used in completions for `make',

but it may be extended depending on authorial frustra-

tion. users This may be set to a list of usernames to be completed. If it is not set all usernames will be completed. Note

that if it is set only that list of users will be com-

pleted; this is because on some systems querying all users can take a prohibitive amount of time.

users-hosts

The values of this style should be of the form `user@host' or `user:host'. It is used for commands

that need pairs of user- and hostnames. These commands

will complete usernames from this style (only), and will restrict subsequent hostname completion to hosts paired with that user in one of the values of the style. It is possible to group values for sets of commands which allow a remote login, such as rlogin and ssh, by

using the my-accounts tag. Similarly, values for sets

of commands which usually refer to the accounts of other people, such as talk and finger, can be grouped

by using the other-accounts tag. More ambivalent com-

mands may use the accounts tag.

users-hosts-ports

Like users-hosts but used for commands like telnet and

containing strings of the form `user@host:port'. verbose If set, as it is by default, the completion listing is more verbose. In particular many commands show zsh 4.3.10 Last change: June 1, 2009 52 User Commands ZSHCOMPSYS(1) descriptions for options if this style is `true'.

word This is used by the _list completer, which prevents the

insertion of completions until a second completion attempt when the line has not changed. The normal way of finding out if the line has changed is to compare its entire contents between the two occasions. If this style is true, the comparison is instead performed only on the current word. Hence if completion is performed on another word with the same contents, completion will not be delayed. CONTROL FUNCTIONS The initialization script compinit redefines all the widgets

which perform completion to call the supplied widget func-

tion _main_complete. This function acts as a wrapper cal-

ling the so-called `completer' functions that generate

matches. If _main_complete is called with arguments, these

are taken as the names of completer functions to be called in the order given. If no arguments are given, the set of functions to try is taken from the completer style. For example, to use normal completion and correction if that doesn't generate any matches:

zstyle ':completion:*' completer _complete _correct

after calling compinit. The default value for this style is

`_complete _ignored', i.e. normally only ordinary completion

is tried, first with the effect of the ignored-patterns

style and then without it. The _main_complete function uses

the return status of the completer functions to decide if other completers should be called. If the return status is

zero, no other completers are tried and the _main_complete

function returns.

If the first argument to _main_complete is a single hyphen,

the arguments will not be taken as names of completers.

Instead, the second argument gives a name to use in the com-

pleter field of the context and the other arguments give a command name and arguments to call to generate the matches.

The following completer functions are contained in the dis-

tribution, although users may write their own. Note that in contexts the leading underscore is stripped, for example basic completion is performed in the context `:completion::complete:...'.

_all_matches

This completer can be used to add a string consisting

of all other matches. As it influences later com-

pleters it must appear as the first completer in the list. The list of all matches is affected by the zsh 4.3.10 Last change: June 1, 2009 53 User Commands ZSHCOMPSYS(1)

avoid-completer and old-matches styles described above.

It may be useful to use the _generic function described

below to bind _all_matches to its own keystroke, for

example:

zle -C all-matches complete-word _generic

bindkey '^Xa' all-matches

zstyle ':completion:all-matches:*' old-matches only

zstyle ':completion:all-matches::::' completer _all_matches

Note that this does not generate completions by itself: first use any of the standard ways of generating a list of completions, then use ^Xa to show all matches. It is possible instead to add a standard completer to the list and request that the list of all matches should be directly inserted:

zstyle ':completion:all-matches::::' completer _all_matches _complete

zstyle ':completion:all-matches:*' insert true

In this case the old-matches style should not be set.

_approximate

This is similar to the basic _complete completer but

allows the completions to undergo corrections. The maximum number of errors can be specified by the

max-errors style; see the description of approximate

matching in zshexpn(1) for how errors are counted. Normally this completer will only be tried after the

normal _complete completer:

zstyle ':completion:*' completer _complete _approximate

This will give correcting completion if and only if normal completion yields no possible completions. When corrected completions are found, the completer will normally start menu completion allowing you to cycle through these strings. This completer uses the tags corrections and original

when generating the possible corrections and the origi-

nal string. The format style for the former may con-

tain the additional sequences `%e' and `%o' which will

be replaced by the number of errors accepted to gen-

erate the corrections and the original string, respec-

tively. The completer progressively increases the number of

errors allowed up to the limit by the max-errors style,

hence if a completion is found with one error, no com-

pletions with two errors will be shown, and so on. It zsh 4.3.10 Last change: June 1, 2009 54 User Commands ZSHCOMPSYS(1) modifies the completer name in the context to indicate the number of errors being tried: on the first try the

completer field contains `approximate-1', on the second

try `approximate-2', and so on.

When _approximate is called from another function, the

number of errors to accept may be passed with the -a

option. The argument is in the same format as the

max-errors style, all in one string.

Note that this completer (and the _correct completer

mentioned below) can be quite expensive to call, espe-

cially when a large number of errors are allowed. One way to avoid this is to set up the completer style

using the -e option to zstyle so that some completers

are only used when completion is attempted a second time on the same string, e.g.:

zstyle -e ':completion:*' completer '

if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then

_last_try="$HISTNO$BUFFER$CURSOR"

reply=(_complete _match _prefix)

else

reply=(_ignored _correct _approximate)

fi'

This uses the HISTNO parameter and the BUFFER and CUR-

SOR special parameters that are available inside zle and completion widgets to find out if the command line hasn't changed since the last time completion was

tried. Only then are the _ignored, _correct and

_approximate completers called.

_complete

This completer generates all possible completions in a

context-sensitive manner, i.e. using the settings

defined with the compdef function explained above and the current settings of all special parameters. This gives the normal completion behaviour.

To complete arguments of commands, _complete uses the

utility function _normal, which is in turn responsible

for finding the particular function; it is described

below. Various contexts of the form -context- are han-

dled specifically. These are all mentioned above as

possible arguments to the #compdef tag.

Before trying to find a function for a specific con-

text, _complete checks if the parameter `compcontext'

is set. Setting `compcontext' allows the usual comple-

tion dispatching to be overridden which is useful in places such as a function that uses vared for input. If zsh 4.3.10 Last change: June 1, 2009 55 User Commands ZSHCOMPSYS(1) it is set to an array, the elements are taken to be the possible matches which will be completed using the tag `values' and the description `value'. If it is set to an associative array, the keys are used as the possible

completions and the values (if non-empty) are used as

descriptions for the matches. If `compcontext' is set to a string containing colons, it should be of the form `tag:descr:action'. In this case the tag and descr give the tag and description to use and the action indicates what should be completed in one of the forms

accepted by the _arguments utility function described

below. Finally, if `compcontext' is set to a string without colons, the value is taken as the name of the context to use and the function defined for that context will

be called. For this purpose, there is a special con-

text named -command-line- that completes whole command

lines (commands and their arguments). This is not used

by the completion system itself but is nonetheless han-

dled when explicitly called.

_correct

Generate corrections, but not completions, for the

current word; this is similar to _approximate but will

not allow any number of extra characters at the cursor as that completer does. The effect is similar to

spell-checking. It is based on _approximate, but the

completer field in the context name is correct. For example, with:

zstyle ':completion:::::' completer _complete _correct _approximate

zstyle ':completion:*:correct:::' max-errors 2 not-numeric

zstyle ':completion:*:approximate:::' max-errors 3 numeric

correction will accept up to two errors. If a numeric argument is given, correction will not be performed, but correcting completion will be, and will accept as many errors as given by the numeric argument. Without

a numeric argument, first correction and then correct-

ing completion will be tried, with the first one accepting two errors and the second one accepting three errors.

When _correct is called as a function, the number of

errors to accept may be given following the -a option.

The argument is in the same form a values to the accept style, all in one string. This completer function is intended to be used without

the _approximate completer or, as in the example, just

zsh 4.3.10 Last change: June 1, 2009 56 User Commands ZSHCOMPSYS(1)

before it. Using it after the _approximate completer

is useless since _approximate will at least generate

the corrected strings generated by the _correct com-

pleter -- and probably more.

_expand

This completer function does not really perform comple-

tion, but instead checks if the word on the command line is eligible for expansion and, if it is, gives detailed control over how this expansion is done. For this to happen, the completion system needs to be

invoked with complete-word, not expand-or-complete (the

default binding for TAB), as otherwise the string will be expanded by the shell's internal mechanism before

the completion system is started. Note also this com-

pleter should be called before the _complete completer

function. The tags used when generating expansions are

all-expansions for the string containing all possible

expansions, expansions when adding the possible expan-

sions as single matches and original when adding the original string from the line. The order in which

these strings are generated, if at all, can be con-

trolled by the group-order and tag-order styles, as

usual.

The format string for all-expansions and for expansions

may contain the sequence `%o' which will be replaced by

the original string from the line. The kind of expansion to be tried is controlled by the

substitute, glob and subst-globs-only styles.

It is also possible to call _expand as a function, in

which case the different modes may be selected with

options: -s for substitute, -g for glob and -o for

subst-globs-only.

_expand_alias

If the word the cursor is on is an alias, it is expanded and no other completers are called. The types of aliases which are to be expanded can be controlled with the styles regular, global and disabled.

This function is also a bindable command, see the sec-

tion `Bindable Commands' below.

_history

Complete words from the shell's command history. This

completer can be controlled by the remove-all-dups, and

sort styles as for the _history_complete_word bindable

zsh 4.3.10 Last change: June 1, 2009 57 User Commands ZSHCOMPSYS(1) command, see the section `Bindable Commands' below and the section `Completion System Configuration' above.

_ignored

The ignored-patterns style can be set to a list of pat-

terns which are compared against possible completions; matching ones are removed. With this completer those

matches can be reinstated, as if no ignored-patterns

style were set. The completer actually generates its own list of matches; which completers are invoked is

determined in the same way as for the _prefix com-

pleter. The single-ignored style is also available as

described above.

_list

This completer allows the insertion of matches to be delayed until completion is attempted a second time without the word on the line being changed. On the first attempt, only the list of matches will be shown. It is affected by the styles condition and word, see the section `Completion System Configuration' above.

_match

This completer is intended to be used after the _com-

plete completer. It behaves similarly but the string on the command line may be a pattern to match against trial completions. This gives the effect of the

GLOB_COMPLETE option.

Normally completion will be performed by taking the pattern from the line, inserting a `*' at the cursor position and comparing the resulting pattern with the possible completions generated. This can be modified

with the match-original style described above.

The generated matches will be offered in a menu comple-

tion unless the insert-unambiguous style is set to

`true'; see the description above for other options for this style. Note that matcher specifications defined globally or used by the completion functions (the styles

matcher-list and matcher) will not be used.

_menu

This completer was written as simple example function to show how menu completion can be enabled in shell code. However, it has the notable effect of disabling

menu selection which can be useful with _generic based

widgets. It should be used as the first completer in the list. Note that this is independent of the setting

of the MENU_COMPLETE option and does not work with the

zsh 4.3.10 Last change: June 1, 2009 58 User Commands ZSHCOMPSYS(1) other menu completion widgets such as

reverse-menu-complete, or accept-and-menu-complete.

_oldlist

This completer controls how the standard completion

widgets behave when there is an existing list of com-

pletions which may have been generated by a special

completion (i.e. a separately-bound completion com-

mand). It allows the ordinary completion keys to con-

tinue to use the list of completions thus generated, instead of producing a new list of ordinary contextual

completions. It should appear in the list of com-

pleters before any of the widgets which generate

matches. It uses two styles: old-list and old-menu,

see the section `Completion System Configuration' above.

_prefix

This completer can be used to try completion with the suffix (everything after the cursor) ignored. In other words, the suffix will not be considered to be part of the word to complete. The effect is similar to the

expand-or-complete-prefix command.

The completer style is used to decide which other com-

pleters are to be called to generate matches. If this style is unset, the list of completers set for the

current context is used -- except, of course, the _pre-

fix completer itself. Furthermore, if this completer appears more than once in the list of completers only

those completers not already tried by the last invoca-

tion of _prefix will be called.

For example, consider this global completer style: zstyle ':completion:*' completer \

_complete _prefix _correct _prefix:foo

Here, the _prefix completer tries normal completion but

ignoring the suffix. If that doesn't generate any

matches, and neither does the call to the _correct com-

pleter after it, _prefix will be called a second time

and, now only trying correction with the suffix ignored. On the second invocation the completer part of the context appears as `foo'.

To use _prefix as the last resort and try only normal

completion when it is invoked:

zstyle ':completion:*' completer _complete ... _prefix

zstyle ':completion::prefix:*' completer _complete

zsh 4.3.10 Last change: June 1, 2009 59 User Commands ZSHCOMPSYS(1)

The add-space style is also respected. If it is set to

`true' then _prefix will insert a space between the

matches generated (if any) and the suffix. Note that this completer is only useful if the

COMPLETE_IN_WORD option is set; otherwise, the cursor

will be moved to the end of the current word before the completion code is called and hence there will be no suffix.

_user_expand

This completer behaves similarly to the _expand com-

pleter but instead performs expansions defined by

users. The styles add-space and sort styles specific

to the _expand completer are usable with _user_expand

in addition to other styles handled more generally by

the completion system. The tag all-expansions is also

available.

The expansion depends on the array style user-expand

being defined for the current context; remember that the context for completers is less specific than that for contextual completion as the full context has not yet been determined. Elements of the array may have one of the following forms:

$hash

hash is the name of an associative array. Note this is not a full parameter expression, merely a

$, suitably quoted to prevent immediate expansion,

followed by the name of an associative array. If the trial expansion word matches a key in hash, the resulting expansion is the corresponding value.

_func

_func is the name of a shell function whose name

must begin with _ but is not otherwise special to

the completion system. The function is called with the trial word as an argument. If the word is to be expanded, the function should set the array reply to a list of expansions. The return status of the function is irrelevant. BINDABLE COMMANDS

In addition to the context-dependent completions provided,

which are expected to work in an intuitively obvious way, there are a few widgets implementing special behaviour which can be bound separately to keys. The following is a list of these and their default bindings.

_bash_completions

This function is used by two widgets, zsh 4.3.10 Last change: June 1, 2009 60 User Commands ZSHCOMPSYS(1)

_bash_complete-word and _bash_list-choices. It exists

to provide compatibility with completion bindings in bash. The last character of the binding determines

what is completed: `!', command names; `$', environment

variables; `@', host names; `/', file names; `~' user names. In bash, the binding preceded by `\e' gives completion, and preceded by `^X' lists options. As

some of these bindings clash with standard zsh bind-

ings, only `\e~' and `^X~' are bound by default. To add the rest, the following should be added to .zshrc after compinit has been run:

for key in '!' '$' '@' '/' '~'; do

bindkey "\e$key" _bash_complete-word

bindkey "^X$key" _bash_list-choices

done This includes the bindings for `~' in case they were already bound to something else; the completion code does not override user bindings.

_correct_filename (^XC)

Correct the filename path at the cursor position. Allows up to six errors in the name. Can also be called with an argument to correct a filename path, independently of zle; the correction is printed on standard output.

_correct_word (^Xc)

Performs correction of the current argument using the usual contextual completions as possible choices. This

stores the string `correct-word' in the function field

of the context name and then calls the _correct com-

pleter.

_expand_alias (^Xa)

This function can be used as a completer and as a bind-

able command. It expands the word the cursor is on if it is an alias. The types of alias expanded can be

controlled with the styles regular, global and dis-

abled. When used as a bindable command there is one additional feature that can be selected by setting the complete style to `true'. In this case, if the word is not the

name of an alias, _expand_alias tries to complete the

word to a full alias name without expanding it. It leaves the cursor directly after the completed word so

that invoking _expand_alias once more will expand the

now-complete alias name.

_expand_word (^Xe)

zsh 4.3.10 Last change: June 1, 2009 61 User Commands ZSHCOMPSYS(1) Performs expansion on the current word: equivalent to

the standard expand-word command, but using the _expand

completer. Before calling it, the function field of

the context is set to `expand-word'.

_generic

This function is not defined as a widget and not bound by default. However, it can be used to define a widget

and will then store the name of the widget in the func-

tion field of the context and call the completion sys-

tem. This allows custom completion widgets with their own set of style settings to be defined easily. For

example, to define a widget that performs normal com-

pletion and starts menu selection:

zle -C foo complete-word _generic

bindkey '...' foo zstyle ':completion:foo:*' menu yes select=1 Note in particular that the completer style may be set for the context in order to change the set of functions

used to generate possible matches. If _generic is

called with arguments, those are passed through to

_main_complete as the list of completers in place of

those defined by the completer style.

_history_complete_word (\e/)

Complete words from the shell's command history. This

uses the list, remove-all-dups, sort, and stop styles.

_most_recent_file (^Xm)

Complete the name of the most recently modified file matching the pattern on the command line (which may be blank). If given a numeric argument N, complete the Nth most recently modified file. Note the completion, if any, is always unique.

_next_tags (^Xn)

This command alters the set of matches used to that for the next tag, or set of tags, either as given by the

tag-order style or as set by default; these matches

would otherwise not be available. Successive invoca-

tions of the command cycle through all possible sets of tags.

_read_comp (^X^R)

Prompt the user for a string, and use that to perform

completion on the current word. There are two possi-

bilities for the string. First, it can be a set of

words beginning `_', for example `_files -/', in which

case the function with any arguments will be called to generate the completions. Unambiguous parts of the zsh 4.3.10 Last change: June 1, 2009 62 User Commands ZSHCOMPSYS(1) function name will be completed automatically (normal completion is not available at this point) until a space is typed. Second, any other string will be passed as a set of arguments to compadd and should hence be an expression specifying what should be completed. A very restricted set of editing commands is available when reading the string: `DEL' and `^H' delete the last character; `^U' deletes the line, and `^C' and

`^G' abort the function, while `RET' accepts the com-

pletion. Note the string is used verbatim as a command line, so arguments must be quoted in accordance with standard shell rules. Once a string has been read, the next call to

_read_comp will use the existing string instead of

reading a new one. To force a new string to be read,

call _read_comp with a numeric argument.

_complete_debug (^X?)

This widget performs ordinary completion, but captures

in a temporary file a trace of the shell commands exe-

cuted by the completion system. Each completion attempt gets its own file. A command to view each of these files is pushed onto the editor buffer stack.

_complete_help (^Xh)

This widget displays information about the context names, the tags, and the completion functions used when completing at the current cursor position. If given a

numeric argument other than 1 (as in `ESC-2 ^Xh'), then

the styles used and the contexts for which they are used will be shown, too.

Note that the information about styles may be incom-

plete; it depends on the information available from the

completion functions called, which in turn is deter-

mined by the user's own styles and other settings.

_complete_help_generic

Unlike other commands listed here, this must be created as a normal ZLE widget rather than a completion widget

(i.e. with zle -N). It is used for generating help

with a widget bound to the _generic widget that is

described above.

If this widget is created using the name of the func-

tion, as it is by default, then when executed it will read a key sequence. This is expected to be bound to a

call to a completion function that uses the _generic

zsh 4.3.10 Last change: June 1, 2009 63 User Commands ZSHCOMPSYS(1) widget. That widget will be executed, and information

provided in the same format that the _complete_help

widget displays for contextual completion. If the widget's name contains debug, for example if it

is created as `zle -N _complete_debug_generic

_complete_help_generic', it will read and execute the

keystring for a generic widget as before, but then gen-

erate debugging information as done by _complete_debug

for contextual completion. If the widget's name contains noread, it will not read a keystring but instead arrange that the next use of a generic widget run in the same shell will have the effect as described above. The widget works by setting the shell parameter

ZSH_TRACE_GENERIC_WIDGET which is read by _generic.

Unsetting the parameter cancels any pending effect of the noread form. For example, after executing the following:

zle -N _complete_debug_generic _complete_help_generic

bindkey '^x:' _complete_debug_generic

typing `C-x :' followed by the key sequence for a gen-

eric widget will cause trace output for that widget to be saved to a file.

_complete_tag (^Xt)

This widget completes symbol tags created by the etags or ctags programmes (note there is no connection with the completion system's tags) stored in a file TAGS, in the format used by etags, or tags, in the format created by ctags. It will look back up the path hierarchy for the first occurrence of either file; if both exist, the file TAGS is preferred. You can specify the full path to a TAGS or tags file by setting

the parameter $TAGSFILE or $tagsfile respectively. The

corresponding completion tags used are etags and vtags, after emacs and vi respectively. UTILITY FUNCTIONS Descriptions follow for utility functions that may be useful when writing completion functions. If functions are installed in subdirectories, most of these reside in the Base subdirectory. Like the example functions for commands in the distribution, the utility functions generating matches all follow the convention of returning status zero

if they generated completions and non-zero if no matching

completions could be added. zsh 4.3.10 Last change: June 1, 2009 64 User Commands ZSHCOMPSYS(1)

Two more features are offered by the _main_complete func-

tion. The arrays compprefuncs and comppostfuncs may contain names of functions that are to be called immediately before or after completion has been tried. A function will only be called once unless it explicitly reinserts itself into the array.

_all_labels [ -x ] [ -12VJ ] tag name descr [ command args ... ]

This is a convenient interface to the _next_label func-

tion below, implementing the loop shown in the

_next_label example. The command and its arguments are

called to generate the matches. The options stored in the parameter name will automatically be inserted into the args passed to the command. Normally, they are put directly after the command, but if one of the args is a single hyphen, they are inserted directly before that. If the hyphen is the last argument, it will be removed from the argument list before the command is called.

This allows _all_labels to be used in almost all cases

where the matches can be generated by a single call to the compadd builtin command or by a call to one of the utility functions. For example: local expl ...

if _requested foo; then

...

_all_labels foo expl '...' compadd ... - $matches

fi Will complete the strings from the matches parameter, using compadd with additional options which will take

precedence over those generated by _all_labels.

_alternative [ -C name ] spec ...

This function is useful in simple cases where multiple tags are available. Essentially it implements a loop

like the one described for the _tags function below.

The tags to use and the action to perform if a tag is requested are described using the specs which are of the form: `tag:descr:action'. The tags are offered

using _tags and if the tag is requested, the action is

executed with the given description descr. The actions

are those accepted by the _arguments function

(described below), excluding the `->state' and `=...'

forms. For example, the action may be a simple function call: zsh 4.3.10 Last change: June 1, 2009 65 User Commands ZSHCOMPSYS(1)

_alternative \

'users:user:_users' \

'hosts:host:_hosts'

offers usernames and hostnames as possible matches,

generated by the _users and _hosts functions respec-

tively.

Like _arguments, this functions uses _all_labels to

execute the actions, which will loop over all sets of tags. Special handling is only required if there is an additional valid tag, for example inside a function

called from _alternative.

Like _tags this function supports the -C option to give

a different name for the argument context field. ...

_arguments [ -nswWACRS ] [ -O name ] [ -M matchspec ] [ : ] spec

This function can be used to give a complete specifica-

tion for completion for a command whose arguments fol-

low standard UNIX option and argument conventions. The following forms specify individual sets of options and arguments; to avoid ambiguity, these may be separated

from the options to _arguments itself by a single

colon. Options to _arguments itself must be in

separate words, i.e. -s -w, not -sw.

With the option -n, _arguments sets the parameter NOR-

MARG to the position of the first normal argument in

the $words array, i.e. the position after the end of

the options. If that argument has not been reached,

NORMARG is set to -1. The caller should declare

`integer NORMARG' if the -n option is passed; otherwise

the parameter is not used. n:message:action n::message:action

This describes the n'th normal argument. The mes-

sage will be printed above the matches generated and the action indicates what can be completed in this position (see below). If there are two colons before the message the argument is optional. If the message contains only white space, nothing will be printed above the matches unless the action adds an explanation string itself. :message:action ::message:action Similar, but describes the next argument, whatever number that happens to be. If all arguments are zsh 4.3.10 Last change: June 1, 2009 66 User Commands ZSHCOMPSYS(1) specified in this form in the correct order the numbers are unnecessary. *:message:action *::message:action *:::message:action

This describes how arguments (usually non-option

arguments, those not beginning with - or +) are to

be completed when neither of the first two forms

was provided. Any number of arguments can be com-

pleted in this fashion.

With two colons before the message, the words spe-

cial array and the CURRENT special parameter are modified to refer only to the normal arguments when the action is executed or evaluated. With three colons before the message they are modified to refer only to the normal arguments covered by this description. optspec optspec:... This describes an option. The colon indicates handling for one or more arguments to the option; if it is not present, the option is assumed to take no arguments.

By default, options are multi-character name, one

`-word' per option. With -s, options may be sin-

gle characters, with more than one option per word, although words starting with two hyphens,

such as `--prefix', are still considered complete

option names. This is suitable for standard GNU options.

The combination of -s with -w allows single-letter

options to be combined in a single word even if one or more of the options take arguments. For

example, if -a takes an argument, with no -s `-ab'

is considered as a single (unhandled) option; with

-s -ab is an option with the argument `b'; with

both -s and -w, -ab may be the option -a and the

option -b with arguments still to come.

The option -W takes this a stage further: it is

possible to complete single-letter options even

after an argument that occurs in the same word. However, it depends on the action performed whether options will really be completed at this point. For more control, use a utility function

like _guard as part of the action.

zsh 4.3.10 Last change: June 1, 2009 67 User Commands ZSHCOMPSYS(1) The following forms are available for the initial optspec, whether or not the option has arguments. *optspec Here optspec is one of the remaining forms below. This indicates the following optspec may be repeated. Otherwise if the corresponding option is already present on the command line to the left of the cursor it will not be offered again.

-optname

+optname In the simplest form the optspec is just the option name beginning with a minus or a plus

sign, such as `-foo'. The first argument for

the option (if any) must follow as a separate word directly after the option.

Either of `-+optname' and `+-optname' can be

used to specify that -optname and +optname

are both valid.

In all the remaining forms, the leading `-'

may be replaced by or paired with `+' in this way.

-optname-

The first argument of the option must come directly after the option name in the same

word. For example, `-foo-:...' specifies

that the completed option and argument will

look like `-fooarg'.

-optname+

The first argument may appear immediately after optname in the same word, or may appear as a separate word after the option. For

example, `-foo+:...' specifies that the com-

pleted option and argument will look like

either `-fooarg' or `-foo arg'.

-optname=

The argument may appear as the next word, or in same word as the option name provided that it is separated from it by an equals sign,

for example `-foo=arg' or `-foo arg'.

-optname=-

The argument to the option must appear after an equals sign in the same word, and may not be given in the next argument. zsh 4.3.10 Last change: June 1, 2009 68 User Commands ZSHCOMPSYS(1) optspec[explanation] An explanation string may be appended to any

of the preceding forms of optspec by enclos-

ing it in brackets, as in `-q[query opera-

tion]'. The verbose style is used to decide whether the explanation strings are displayed with the option in a completion listing. If no bracketed explanation string is given

but the auto-description style is set and

only one argument is described for this optspec, the value of the style is displayed,

with any appearance of the sequence `%d' in

it replaced by the message of the first optarg that follows the optspec; see below. It is possible for options with a literal `+' or `=' to appear, but that character must be quoted, for example

`-\+'.

Each optarg following an optspec must take one of the following forms: :message:action ::message:action An argument to the option; message and action are treated as for ordinary arguments. In the first form, the argument is mandatory, and in the second form it is optional. This group may be repeated for options which take multiple arguments. In other words, :message1:action1:message2:action2 specifies that the option takes two arguments. :*pattern:message:action :*pattern::message:action :*pattern:::message:action This describes multiple arguments. Only the last optarg for an option taking multiple arguments may be given in this form. If the pattern is empty (i.e., :*:), all the remaining words on the line are to be completed as described by the action; otherwise, all the words up to and including a word matching the pattern are to be completed using the action. Multiple colons are treated as for the `*:...' forms for ordinary arguments: when the message is preceded by two colons, the words special array zsh 4.3.10 Last change: June 1, 2009 69 User Commands ZSHCOMPSYS(1) and the CURRENT special parameter are modified during the execution or evaluation of the action to refer only to the words after the option. When preceded by three colons, they are modified to

refer only to the words covered by this descrip-

tion. Any literal colon in an optname, message, or action must be preceded by a backslash, `\:'. Each of the forms above may be preceded by a list in parentheses of option names and argument numbers. If the

given option is on the command line, the options and argu-

ments indicated in parentheses will not be offered. For

example, `(-two -three 1)-one:...' completes the option

`-one'; if this appears on the command line, the options

-two and -three and the first ordinary argument will not be

completed after it. `(-foo):...' specifies an ordinary

argument completion; -foo will not be completed if that

argument is already present. Other items may appear in the list of excluded options to indicate various other items that should not be applied when the current specification is matched: a single star (*) for the rest arguments (i.e. a specification of the form

`*:...'); a colon (:) for all normal (non-option-) argu-

ments; and a hyphen (-) for all options. For example, if

`(*)' appears before an option and the option appears on the command line, the list of remaining arguments (those shown

in the above table beginning with `*:') will not be com-

pleted. To aid in reuse of specifications, it is possible to precede any of the forms above with `!'; then the form will no longer be completed, although if the option or argument appears on the command line they will be skipped as normal. The main use for this is when the arguments are given by an

array, and _arguments is called repeatedly for more specific

contexts: on the first call `_arguments $global_options' is

used, and on subsequent calls `_arguments

!$^global_options'.

In each of the forms above the action determines how comple-

tions should be generated. Except for the `->string' form

below, the action will be executed by calling the

_all_labels function to process all tag labels. No special

handling of tags is needed unless a function call introduces a new one. The forms for action are as follows. zsh 4.3.10 Last change: June 1, 2009 70 User Commands ZSHCOMPSYS(1) (single unquoted space) This is useful where an argument is required but it is not possible or desirable to generate matches for it. The message will be displayed but no completions listed. Note that even in this case the colon at the end of the message is needed; it may only be omitted when neither a message nor an action is given. (item1 item2 ...) One of a list of possible matches, for example: :foo:(foo bar baz) ((item1\:desc1 ...)) Similar to the above, but with descriptions for each possible match. Note the backslash before the colon. For example, :foo:((a\:bar b\:baz))

The matches will be listed together with their descrip-

tions if the description style is set with the values tag in the context.

->string

In this form, _arguments processes the arguments and

options and then returns control to the calling func-

tion with parameters set to indicate the state of pro-

cessing; the calling function then makes its own arrangements for generating completions. For example, functions that implement a state machine can use this type of action.

Where _arguments encounters a `->string', it will strip

all leading and trailing whitespace from string and set the array state to the set of all stringss for which an action is to be performed. By default and in common with all other well behaved

completion functions, _arguments returns status zero if

it was able to add matches and non-zero otherwise. How-

ever, if the -R option is given, _arguments will

instead return a status of 300 to indicate that $state

is to be handled.

In addition to $state, _arguments also sets the global

parameters `context', `line' and `opt_args' as

described below, and does not reset any changes made to the special parameters such as PREFIX and words. This gives the calling function the choice of resetting these parameters or propagating changes in them. zsh 4.3.10 Last change: June 1, 2009 71 User Commands ZSHCOMPSYS(1)

A function calling _arguments with at least one action

containing a `->string' therefore must declare

appropriate local parameters: local context state line

typeset -A opt_args

to avoid _arguments from altering the global environ-

ment.

{eval-string}

A string in braces is evaluated as shell code to gen-

erate matches. If the eval-string itself does not

begin with an opening parenthesis or brace it is split into separate words before execution. = action If the action starts with `= ' (an equals sign followed

by a space), _arguments will insert the contents of the

argument field of the current context as the new first element in the words special array and increment the value of the CURRENT special parameter. This has the effect of inserting a dummy word onto the completion

command line while not changing the point at which com-

pletion is taking place. This is most useful with one of the specifiers that restrict the words on the command line on which the

action is to operate (the two- and three-colon forms

above). One particular use is when an action itself

causes _arguments on a restricted range; it is neces-

sary to use this trick to insert an appropriate command

name into the range for the second call to _arguments

to be able to parse the line. word... word... This covers all forms other than those above. If the action starts with a space, the remaining list of words will be invoked unchanged. Otherwise it will be invoked with some extra strings placed after the first word; these are to be passed down as options to the compadd builtin. They ensure

that the state specified by _arguments, in particular

the descriptions of options and arguments, is correctly passed to the completion command. These additional arguments are taken from the array parameter `expl'; this will be set up before executing the action and hence may be referred to inside it, typically in an

expansion of the form `$expl[@]' which preserves empty

elements of the array. zsh 4.3.10 Last change: June 1, 2009 72 User Commands ZSHCOMPSYS(1) During the performance of the action the array `line' will be set to the command name and normal arguments from the command line, i.e. the words from the command line excluding all options and their arguments. Options are stored in the

associative array `opt_args' with option names as keys and

their arguments as the values. For options that have more than one argument these are given as one string, separated

by colons. All colons in the original arguments are pre-

ceded with backslashes. The parameter `context' is set when returning to the calling

function to perform an action of the form `->string'. It is

set to an array of elements corresponding to the elements of

$state. Each element is a suitable name for the argument

field of the context: either a string of the form

`option-opt-n' for the n'th argument of the option -opt, or

a string of the form `argument-n' for the n'th argument.

For `rest' arguments, that is those in the list at the end

not handled by position, n is the string `rest'. For exam-

ple, when completing the argument of the -o option, the name

is `option-o-1', while for the second normal (non-option-)

argument it is `argument-2'.

Furthermore, during the evaluation of the action the context name in the curcontext parameter is altered to append the same string that is stored in the context parameter.

It is possible to specify multiple sets of options and argu-

ments with the sets separated by single hyphens. The specifications before the first hyphen (if any) are shared by all the remaining sets. The first word in every other

set provides a name for the set which may appear in exclu-

sion lists in specifications, either alone or before one of the possible values described above. In the second case a

`-' should appear between this name and the remainder.

For example:

_arguments \

-a \

- set1 \

-c \

- set2 \

-d \

':arg:(x2 y2)' This defines two sets. When the command line contains the

option `-c', the `-d' option and the argument will not be

considered possible completions. When it contains `-d' or

an argument, the option `-c' will not be considered. How-

ever, after `-a' both sets will still be considered valid.

zsh 4.3.10 Last change: June 1, 2009 73 User Commands ZSHCOMPSYS(1) If the name given for one of the mutually exclusive sets is of the form `(name)' then only one value from each set will ever be completed; more formally, all specifications are mutually exclusive to all other specifications in the same set. This is useful for defining multiple sets of options which are mutually exclusive and in which the options are aliases for each other. For example:

_arguments \

-a -b \

- '(compress)' \

{-c,--compress}'[compress]' \

- '(uncompress)' \

{-d,--decompress}'[decompress]'

As the completion code has to parse the command line separately for each set this form of argument is slow and should only be used when necessary. A useful alternative is

often an option specification with rest-arguments (as in

`-foo:*:...'); here the option -foo swallows up all remain-

ing arguments as described by the optarg definitions.

The options -S and -A are available to simplify the specifi-

cations for commands with standard option parsing. With -S,

no option will be completed after a `--' appearing on its

own on the line; this argument will otherwise be ignored; hence in the line

foobar -a -- -b

the `-a' is considered an option but the `-b' is considered

an argument, while the `--' is considered to be neither.

With -A, no options will be completed after the first

non-option argument on the line. The -A must be followed by

a pattern matching all strings which are not to be taken as

arguments. For example, to make _arguments stop completing

options after the first normal argument, but ignoring all strings starting with a hyphen even if they are not

described by one of the optspecs, the form is `-A "-*"'.

The option `-O name' specifies the name of an array whose

elements will be passed as arguments to functions called to execute actions. For example, this can be used to pass the same set of options for the compadd builtin to all actions.

The option `-M spec' sets a match specification to use to

completion option names and values. It must appear before

the first argument specification. The default is `r:|[_-]=*

r:|=*': this allows partial word completion after `_' and

`-', for example `-f-b' can be completed to `-foo-bar'.

zsh 4.3.10 Last change: June 1, 2009 74 User Commands ZSHCOMPSYS(1)

The option -C tells _arguments to modify the curcontext

parameter for an action of the form `->state'. This is the

standard parameter used to keep track of the current con-

text. Here it (and not the context array) should be made local to the calling function to avoid passing back the modified value and should be initialised to the current value at the start of the function:

local curcontext="$curcontext"

This is useful where it is not possible for multiple states to be valid together.

The option `--' allows _arguments to work out the names of

long options that support the `--help' option which is stan-

dard in many GNU commands. The command word is called with

the argument `--help' and the output examined for option

names. Clearly, it can be dangerous to pass this to com-

mands which may not support this option as the behaviour of the command is unspecified.

In addition to options, `_arguments --' will try to deduce

the types of arguments available for options when the form

`--opt=val' is valid. It is also possible to provide hints

by examining the help text of the command and adding specif-

iers of the form `pattern:message:action'; note that normal

_arguments specifiers are not used. The pattern is matched

against the help text for an option, and if it matches the

message and action are used as for other argument specif-

iers. For example:

_arguments -- '*\*:toggle:(yes no)' \

'*=FILE*:file:_files' \

'*=DIR*:directory:_files -/' \

'*=PATH*:directory:_files -/'

Here, `yes' and `no' will be completed as the argument of options whose description ends in a star; file names will be completed for options that contain the substring `=FILE' in the description; and directories will be completed for options whose description contains `=DIR' or `=PATH'. The last three are in fact the default and so need not be given explicitly, although it is possible to override the use of these patterns. A typical help text which uses this feature is:

-C, --directory=DIR change to directory DIR

so that the above specifications will cause directories to

be completed after `--directory', though not after `-C'.

zsh 4.3.10 Last change: June 1, 2009 75 User Commands ZSHCOMPSYS(1)

Note also that _arguments tries to find out automatically if

the argument for an option is optional. This can be speci-

fied explicitly by doubling the colon before the message.

If the pattern ends in `(-)', this will removed from the

pattern and the action will be used only directly after the

`=', not in the next word. This is the behaviour of a nor-

mal specification defined with the form `=-'.

The `_arguments --' can be followed by the option `-i pat-

terns' to give patterns for options which are not to be com-

pleted. The patterns can be given as the name of an array parameter or as a literal list in parentheses. For example,

_arguments -- -i \

"(--(en|dis)able-FEATURE*)"

will cause completion to ignore the options

`--enable-FEATURE' and `--disable-FEATURE' (this example is

useful with GNU configure).

The `_arguments --' form can also be followed by the option

`-s pair' to describe option aliases. Each pair consists of

a pattern and a replacement. For example, some

configure-scripts describe options only as `--enable-foo',

but also accept `--disable-foo'. To allow completion of the

second form:

_arguments -- -s "(#--enable- --disable-)"

Here is a more general example of the use of _arguments:

_arguments '-l+:left border:' \

'-format:paper size:(letter A4)' \

'*-copy:output file:_files::resolution:(300 600)' \

':postscript file:_files -g \*.$ps\|eps$' \

'*:page number:'

This describes three options: `-l', `-format', and `-copy'.

The first takes one argument described as `left border' for which no completion will be offered because of the empty

action. Its argument may come directly after the `-l' or it

may be given as the next word on the line.

The `-format' option takes one argument in the next word,

described as `paper size' for which only the strings `letter' and `A4' will be completed.

The `-copy' option may appear more than once on the command

line and takes two arguments. The first is mandatory and will be completed as a filename. The second is optional (because of the second colon before the description zsh 4.3.10 Last change: June 1, 2009 76 User Commands ZSHCOMPSYS(1) `resolution') and will be completed from the strings `300' and `600'. The last two descriptions say what should be completed as arguments. The first describes the first argument as a `postscript file' and makes files ending in `ps' or `eps' be completed. The last description gives all other arguments

the description `page numbers' but does not offer comple-

tions.

_cache_invalid cache_identifier

This function returns status zero if the completions cache

corresponding to the given cache identifier needs rebuild-

ing. It determines this by looking up the cache-policy

style for the current context. This should provide a func-

tion name which is run with the full path to the relevant cache file as the only argument. Example:

_example_caching_policy () {

# rebuild if cache is more than a week old

local -a oldp

oldp=( "$1"(Nmw+1) )

(( $#oldp ))

}

_call_function return name [ args ... ]

If a function name exists, it is called with the arguments args. The return argument gives the name of a parameter in which the return status from the function name; if return is empty or a single hyphen it is ignored.

The return status of _call_function itself is zero if the

function name exists and was called and non-zero otherwise.

_call_program tag string ...

This function provides a mechanism for the user to override the use of an external command. It looks up the command style with the supplied tag. If the style is set, its value is used as the command to execute. The strings from the

call to _call_program, or from the style if set, are con-

catenated with spaces between them and the resulting string is evaluated. The return status is the return status of the command called.

_combination [ -s pattern ] tag style spec ... field opts ...

This function is used to complete combinations of values, for example pairs of hostnames and usernames. The style argument gives the style which defines the pairs; it is looked up in a context with the tag specified. zsh 4.3.10 Last change: June 1, 2009 77 User Commands ZSHCOMPSYS(1) The style name consists of field names separated by hyphens,

for example `users-hosts-ports'. For each field for a value

is already known, a spec of the form `field=pattern' is given. For example, if the command line so far specifies a user `pws', the argument `users=pws' should appear. The next argument with no equals sign is taken as the name of the field for which completions should be generated (presumably not one of the fields for which the value is known). The matches generated will be taken from the value of the style. These should contain the possible values for the combinations in the appropriate order (users, hosts, ports in the example above). The different fields the values for the different fields are separated by colons. This can be

altered with the option -s to _combination which specifies a

pattern. Typically this is a character class, as for exam-

ple `-s "[:@]"' in the case of the users-hosts style.

Each `field=pattern' specification restricts the completions which apply to elements of the style with appropriately matching fields. If no style with the given name is defined for the given tag, or if none of the strings in style's value match, but a

function name of the required field preceded by an under-

score is defined, that function will be called to generate the matches. For example, if there is no

`users-hosts-ports' or no matching hostname when a host is

required, the function `_hosts' will automatically be

called. If the same name is used for more than one field, in both the `field=pattern' and the argument that gives the name of the field to be completed, the number of the field (starting with one) may be given after the fieldname, separated from it by a colon. All arguments after the required field name are passed to compadd when generating matches from the style value, or to the functions for the fields if they are called.

_describe [ -oO | -t tag ] descr name1 [ name2 ] opts ... -- ...

This function associates completions with descriptions.

Multiple groups separated by -- can be supplied, potentially

with different completion options opts. The descr is taken as a string to display above the matches if the format style for the descriptions tag is set. This is followed by one or two names of arrays followed by options to pass to compadd. The first array contains the possible completions with their descriptions in the form zsh 4.3.10 Last change: June 1, 2009 78 User Commands ZSHCOMPSYS(1) `completion:description'. Any literal colons in completion must be quoted with a backslash. If a second array is given, it should have the same number of elements as the first; in this case the corresponding elements are added as possible completions instead of the completion strings from the first array. The completion list will retain the

descriptions from the first array. Finally, a set of com-

pletion options can appear.

If the option `-o' appears before the first argument, the

matches added will be treated as names of command options

(N.B. not shell options), typically following a `-', `--' or

`+' on the command line. In this case _describe uses the

prefix-hidden, prefix-needed and verbose styles to find out

if the strings should be added as completions and if the

descriptions should be shown. Without the `-o' option, only

the verbose style is used to decide how descriptions are

shown. If `-O' is used instead of `-O', command options are

completed as above but _describe will not handle the

prefix-needed style.

With the -t option a tag can be specified. The default is

`values' or, if the -o option is given, `options'.

If selected by the list-grouped style, strings with the same

description will appear together in the list.

_describe uses the _all_labels function to generate the

matches, so it does not need to appear inside a loop over tag labels.

_description [ -x ] [ -12VJ ] tag name descr [ spec ... ]

This function is not to be confused with the previous one;

it is used as a helper function for creating options to com-

padd. It is buried inside many of the higher level comple-

tion functions and so often does not need to be called directly. The styles listed below are tested in the current context using the given tag. The resulting options for compadd are put into the array named name (this is traditionally `expl', but this convention is not enforced). The description for the corresponding set of matches is passed to the function in descr. The styles tested are: format, hidden, matcher,

ignored-patterns and group-name. The format style is first

tested for the given tag and then for the descriptions tag if no value was found, while the remainder are only tested for the tag given as the first argument. The function also

calls _setup which tests some more styles.

zsh 4.3.10 Last change: June 1, 2009 79 User Commands ZSHCOMPSYS(1) The string returned by the format style (if any) will be

modified so that the sequence `%d' is replaced by the descr

given as the third argument without any leading or trailing white space. If, after removing the white space, the descr is the empty string, the format style will not be used and the options put into the name array will not contain an explanation string to be displayed above the matches.

If _description is called with more than three arguments,

the additional specs should be of the form `char:str'. These supply escape sequence replacements for the format

style: every appearance of `%char' will be replaced by

string.

If the -x option is given, the description will be passed to

compadd using the -x option instead of the default -X. This

means that the description will be displayed even if there are no corresponding matches. The options placed in the array name take account of the

group-name style, so matches are placed in a separate group

where necessary. The group normally has its elements sorted

(by passing the option -J to compadd), but if an option

starting with `-V', `-J', `-1', or `-2' is passed to

_description, that option will be included in the array.

Hence it is possible for the completion group to be unsorted

by giving the option `-V', `-1V', or `-2V'.

In most cases, the function will be used like this: local expl

_description files expl file

compadd "$expl[@]" - "$files[@]"

Note the use of the parameter expl, the hyphen, and the list

of matches. Almost all calls to compadd within the comple-

tion system use a similar format; this ensures that

user-specified styles are correctly passed down to the buil-

tins which implement the internals of completion.

_dispatch context string ...

This sets the current context to context and looks for com-

pletion functions to handle this context by hunting through the list of command names or special contexts (as described

above for compdef) given as string .... The first comple-

tion function to be defined for one of the contexts in the list is used to generate matches. Typically, the last

string is -default- to cause the function for default com-

pletion to be used as a fallback.

The function sets the parameter $service to the string being

tried, and sets the context/command field (the fourth) of zsh 4.3.10 Last change: June 1, 2009 80 User Commands ZSHCOMPSYS(1)

the $curcontext parameter to the context given as the first

argument.

_files

The function _files calls _path_files with all the arguments

it was passed except for -g and -/. The use of these two

options depends on the setting of the file-patterns style.

This function accepts the full set of options allowed by

_path_files, described below.

_gnu_generic

This function is a simple wrapper around the _arguments

function described above. It can be used to determine automatically the long options understood by commands that

produce a list when passed the option `--help'. It is

intended to be used as a top-level completion function in

its own right. For example, to enable option completion for the commands foo and bar, use

compdef _gnu_generic foo bar

after the call to compinit. The completion system as supplied is conservative in its use

of this function, since it is important to be sure the com-

mand understands the option `--help'.

_guard [ options ] pattern descr

This function is intended to be used in the action for the

specifications passed to _arguments and similar functions.

It returns immediately with a non-zero return status if the

string to be completed does not match the pattern. If the pattern matches, the descr is displayed; the function then returns status zero if the word to complete is not empty,

non-zero otherwise.

The pattern may be preceded by any of the options understood

by compadd that are passed down from _description, namely

-M, -J, -V, -1, -2, -n, -F and -X. All of these options

will be ignored. This fits in conveniently with the

argument-passing conventions of actions for _arguments.

As an example, consider a command taking the options -n and

-none, where -n must be followed by a numeric value in the

same word. By using:

_arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'

_arguments can be made to both display the message `numeric

value' and complete options after `-n'. If the `-n' is

already followed by one or more digits (the pattern passed zsh 4.3.10 Last change: June 1, 2009 81 User Commands ZSHCOMPSYS(1)

to _guard) only the message will be displayed; if the `-n'

is followed by another character, only options are com-

pleted.

_message [ -r12 ] [ -VJ group ] descr

_message -e [ tag ] descr

The descr is used in the same way as the third argument to

the _description function, except that the resulting string

will always be shown whether or not matches were generated. This is useful for displaying a help message in places where no completions can be generated. The format style is examined with the messages tag to find a message; the usual tag, descriptions, is used only if the style is not set with the former.

If the -r option is given, no style is used; the descr is

taken literally as the string to display. This is most use-

ful when the descr comes from a pre-processed argument list

which already contains an expanded description.

The -12VJ options and the group are passed to compadd and

hence determine the group the message string is added to. The second form gives a description for completions with the tag tag to be shown even if there are no matches for that tag. The tag can be omitted and if so the tag is taken from

the parameter $curtag; this is maintained by the completion

system and so is usually correct.

_multi_parts sep array

The argument sep is a separator character. The array may be either the name of an array parameter or a literal array in the form `(foo bar)', a parenthesised list of words separated by whitespace. The possible completions are the strings from the array. However, each chunk delimited by

sep will be completed separately. For example, the _tar

function uses `_multi_parts / patharray' to complete partial

file paths from the given array of complete file paths.

The -i option causes _multi_parts to insert a unique match

even if that requires multiple separators to be inserted. This is not usually the expected behaviour with filenames, but certain other types of completion, for example those with a fixed set of possibilities, may be more suited to this form. Like other utility functions, this function accepts the

`-V', `-J', `-1', `-2', `-n', `-f', `-X', `-M', `-P', `-S',

`-r', `-R', and `-q' options and passes them to the compadd

builtin. zsh 4.3.10 Last change: June 1, 2009 82 User Commands ZSHCOMPSYS(1)

_next_label [ -x ] [ -12VJ ] tag name descr [ options ... ]

This function is used to implement the loop over different tag labels for a particular tag as described above for the

tag-order style. On each call it checks to see if there are

any more tag labels; if there is it returns status zero,

otherwise non-zero. As this function requires a current tag

to be set, it must always follow a call to _tags or

_requested.

The -x12VJ options and the first three arguments are passed

to the _description function. Where appropriate the tag

will be replaced by a tag label in this call. Any descrip-

tion given in the tag-order style is preferred to the descr

passed to _next_label.

The options given after the descr are set in the parameter given by name, and hence are to be passed to compadd or whatever function is called to add the matches. Here is a typical use of this function for the tag foo. The

call to _requested determines if tag foo is required at all;

the loop over _next_label handles any labels defined for the

tag in the tag-order style.

local expl ret=1 ...

if _requested foo; then

...

while _next_label foo expl '...'; do

compadd "$expl[@]" ... && ret=0

done ... fi return ret

_normal

This is the standard function called to handle completion

outside any special -context-. It is called both to com-

plete the command word and also the arguments for a command.

In the second case, _normal looks for a special completion

for that command, and if there is none it uses the comple-

tion for the -default- context.

A second use is to reexamine the command line specified by

the $words array and the $CURRENT parameter after those have

been modified. For example, the function _precommand, which

completes after pre-command specifiers such as nohup,

removes the first word from the words array, decrements the

CURRENT parameter, then calls _normal again. The effect is

that `nohup cmd ...' is treated in the same way as `cmd ...'. zsh 4.3.10 Last change: June 1, 2009 83 User Commands ZSHCOMPSYS(1) If the command name matches one of the patterns given by one

of the options -p or -P to compdef, the corresponding com-

pletion function is called and then the parameter _compskip

is checked. If it is set completion is terminated at that point even if no matches have been found. This is the same

effect as in the -first- context.

_options

This can be used to complete the names of shell options. It provides a matcher specification that ignores a leading

`no', ignores underscores and allows upper-case letters to

match their lower-case counterparts (for example, `glob',

`noglob', `NO_GLOB' are all completed). Any arguments are

propagated to the compadd builtin.

_options_set and _options_unset

These functions complete only set or unset options, with the

same matching specification used in the _options function.

Note that you need to uncomment a few lines in the

_main_complete function for these functions to work prop-

erly. The lines in question are used to store the option settings in effect before the completion widget locally sets

the options it needs. Hence these functions are not gen-

erally used by the completion system.

_parameters

This is used to complete the names of shell parameters.

The option `-g pattern' limits the completion to parameters

whose type matches the pattern. The type of a parameter is

that shown by `print ${(t)param}', hence judicious use of

`*' in pattern is probably necessary. All other arguments are passed to the compadd builtin.

_path_files

This function is used throughout the completion system to complete filenames. It allows completion of partial paths. For example, the string `/u/i/s/sig' may be completed to `/usr/include/sys/signal.h'.

The options accepted by both _path_files and _files are:

-f Complete all filenames. This is the default.

-/ Specifies that only directories should be completed.

-g pattern

Specifies that only files matching the pattern should be completed. zsh 4.3.10 Last change: June 1, 2009 84 User Commands ZSHCOMPSYS(1)

-W paths

Specifies path prefixes that are to be prepended to the string from the command line to generate the filenames but that should not be inserted as completions nor shown in completion listings. Here, paths may be the name of an array parameter, a literal list of paths enclosed in parentheses or an absolute pathname.

-F ignored-files

This behaves as for the corresponding option to the compadd builtin. It gives direct control over which filenames should be ignored. If the option is not

present, the ignored-patterns style is used.

Both _path_files and _files also accept the following

options which are passed to compadd: `-J', `-V', `-1', `-2',

`-n', `-X', `-M', `-P', `-S', `-q', `-r', and `-R'.

Finally, the _path_files function uses the styles expand,

ambiguous, special-dirs, list-suffixes and file-sort

described above. [ args ... ]

_pick_variant [ -c command ] [ -r name ] label=pattern ... label

This function is used to resolve situations where a single command name requires more than one type of handling, either because it has more than one variant or because there is a name clash between two different commands. The command to run is taken from the first element of the

array words unless this is overridden by the option -c.

This command is run and its output is compared with a series of patterns. Arguments to be passed to the command can be specified at the end after all the other arguments. The patterns to try in order are given by the arguments label=pattern; if the output of `command args ...' contains pattern, then label is selected as the label for the command variant. If none of the patterns match, the final command label is selected and status 1 is returned.

If the `-r name' is given, the label picked is stored in the

parameter named name.

The results are also cached in the _cmd_variant associative

array indexed by the name of the command run.

_regex_arguments name spec ...

This function generates a completion function name which matches the specifications spec ..., a set of regular expressions as described below. After running

_regex_arguments, the function name should be called as a

normal completion function. The pattern to be matched is zsh 4.3.10 Last change: June 1, 2009 85 User Commands ZSHCOMPSYS(1) given by the contents of the words array up to the current cursor position joined together with null characters; no quotation is applied. The arguments are grouped as sets of alternatives separated by `|', which are tried one after the other until one

matches. Each alternative consists of a one or more specif-

ications which are tried left to right, with each pattern matched being stripped in turn from the command line being tested, until all of the group succeeds or until one fails; in the latter case, the next alternative is tried. This structure can be repeated to arbitrary depth by using parentheses; matching proceeds from inside to outside. A special procedure is applied if no test succeeds but the remaining command line string contains no null character

(implying the remaining word is the one for which comple-

tions are to be generated). The completion target is res-

tricted to the remaining word and any actions for the corresponding patterns are executed. In this case, nothing is stripped from the command line string. The order of

evaluation of the actions can be determined by the tag-order

style; the various formats supported by _alternative can be

used in action. The descr is used for setting up the array parameter expl. Specification arguments take one of following forms, in

which metacharacters such as `(', `)', `#' and `|' should be

quoted.

/pattern/ [%lookahead%] [-guard] [:tag:descr:action]

This is a single primitive component. The function tests whether the combined pattern

`(#b)((#B)pattern)lookahead*' matches the command line

string. If so, `guard' is evaluated and its return

status is examined to determine if the test has suc-

ceeded. The pattern string `[]' is guaranteed never to match. The lookahead is not stripped from the command line before the next pattern is examined. The argument starting with : is used in the same manner

as an argument to _alternative.

A component is used as follows: pattern is tested to see if the component already exists on the command line. If it does, any following specifications are examined to find something to complete. If a component

is reached but no such pattern exists yet on the com-

mand line, the string containing the action is used to generate matches to insert at that point.

/pattern/+ [%lookahead%] [-guard] [:tag:descr:action]

zsh 4.3.10 Last change: June 1, 2009 86 User Commands ZSHCOMPSYS(1) This is similar to `/pattern/ ...' but the left part of the command line string (i.e. the part already matched by previous patterns) is also considered part of the completion target.

/pattern/- [%lookahead%] [-guard] [:tag:descr:action]

This is similar to `/pattern/ ...' but the actions of the current and previously matched patterns are ignored even if the following `pattern' matches the empty string. ( spec ) Parentheses may be used to groups specs; note each

parenthesis is a single argument to _regex_arguments.

spec #

This allows any number of repetitions of spec. spec spec The two specs are to be matched one after the other as described above. spec | spec Either of the two specs can be matched.

The function _regex_words can be used as a helper function

to generate matches for a set of alternative words possibly with their own arguments as a command line argument. Examples:

_regex_arguments _tst /$'[^\0]#\0'/ \

/$'[^\0]#\0'/ :'compadd aaa'

This generates a function _tst that completes aaa as its

only argument. The tag and description for the action have been omitted for brevity (this works but is not recommended in normal use). The first component matches the command word, which is arbitrary; the second matches any argument. As the argument is also arbitrary, any following component would not depend on aaa being present.

_regex_arguments _tst /$'[^\0]#\0'/ \

/$'aaa\0'/ :'compadd aaa'

This is a more typical use; it is similar, but any following patterns would only match if aaa was present as the first argument.

_regex_arguments _tst /$'[^\0]#\0'/ \( \

/$'aaa\0'/ :'compadd aaa' \

/$'bbb\0'/ :'compadd bbb' \) \#

zsh 4.3.10 Last change: June 1, 2009 87 User Commands ZSHCOMPSYS(1) In this example, an indefinite number of command arguments may be completed. Odd arguments are completed as aaa and even arguments as bbb. Completion fails unless the set of aaa and bbb arguments before the current one is matched correctly.

_regex_arguments _tst /$'[^\0]#\0'/ \

\( /$'aaa\0'/ :'compadd aaa' \| \

/$'bbb\0'/ :'compadd bbb' \) \#

This is similar, but either aaa or bbb may be completed for

any argument. In this case _regex_words could be used to

generate a suitable expression for the arguments.

_regex_words tag description spec ...

This function can be used to generate arguments for the

_regex_arguments command which may be inserted at any point

where a set of rules is expected. The tag and description give a standard tag and description pertaining to the current context. Each spec contains two or three arguments separated by a colon: note that there is no leading colon in this case. Each spec gives one of a set of words that may be completed at this point, together with arguments. It is thus roughly

equivalent to the _arguments function when used in normal

(non-regex) completion.

The part of the spec before the first colon is the word to be completed. This may contain a *; the entire word, before and after the * is completed, but only the text before the * is required for the context to be matched, so that further arguments may be completed after the abbreviated form. The second part of spec is a description for the word being completed.

The optional third part of the spec describes how words fol-

lowing the one being completed are themselves to be com-

pleted. It will be evaluated in order to avoid problems with quoting. This means that typically it contains a reference to an array containing previously generated regex arguments.

The option -t term specifies a terminator for the word

instead of the usual space. This is handled as an

auto-removable suffix in the manner of the option -s sep to

_values.

The result of the processing by _regex_words is placed in

the array reply, which should be made local to the calling function. If the set of words and arguments may be matched zsh 4.3.10 Last change: June 1, 2009 88 User Commands ZSHCOMPSYS(1)

repeatedly, a # should be appended to the generated array at

that point. For example:

local -a reply

_regex_words mydb-commands 'mydb commands' \

'add:add an entry to mydb:$mydb_add_cmds' \

'show:show entries in mydb'

_regex_arguments _mydb "$reply[@]"

_mydb "$@"

This shows a completion function for a command mydb which takes two command arguments, add and show. show takes no arguments, while the arguments for add have already been

prepared in an array mydb_add_cmds, quite possibly by a pre-

vious call to _regex_words.

]

_requested [ -x ] [ -12VJ ] tag [ name descr [ command args ... ]

This function is called to decide whether a tag already

registered by a call to _tags (see below) has been requested

by the user and hence completion should be performed for it.

It returns status zero if the tag is requested and non-zero

otherwise. The function is typically used as part of a loop over different tags as follows:

_tags foo bar baz

while _tags; do

if _requested foo; then

... # perform completion for foo

... # test the tags bar and baz in the same way

... # exit loop if matches were generated

done Note that the test for whether matches were generated is not

performed until the end of the _tags loop. This is so that

the user can set the tag-order style to specify a set of

tags to be completed at the same time.

If name and descr are given, _requested calls the _descrip-

tion function with these arguments together with the options

passed to _requested.

If command is given, the _all_labels function will be called

immediately with the same arguments. In simple cases this makes it possible to perform the test for the tag and the matching in one go. For example: local expl ret=1

_tags foo bar baz

zsh 4.3.10 Last change: June 1, 2009 89 User Commands ZSHCOMPSYS(1)

while _tags; do

_requested foo expl 'description' \

compadd foobar foobaz && ret=0 ... (( ret )) || break done If the command is not compadd, it must nevertheless be prepared to handle the same options.

_retrieve_cache cache_identifier

This function retrieves completion information from the file

given by cache_identifier, stored in a directory specified

by the cache-path style which defaults to ~/.zcompcache.

The return status is zero if retrieval was successful. It

will only attempt retrieval if the use-cache style is set,

so you can call this function without worrying about whether the user wanted to use the caching layer.

See _store_cache below for more details.

_sep_parts

This function is passed alternating arrays and separators as arguments. The arrays specify completions for parts of strings to be separated by the separators. The arrays may be the names of array parameters or a quoted list of words in parentheses. For example, with the array `hosts=(ftp

news)' the call `_sep_parts '(foo bar)' @ hosts' will com-

plete the string `f' to `foo' and the string `b@n' to `bar@news'.

This function accepts the compadd options `-V', `-J', `-1',

`-2', `-n', `-X', `-M', `-P', `-S', `-r', `-R', and `-q' and

passes them on to the compadd builtin used to add the matches.

_setup tag [ group ]

This function sets up the special parameters used by the completion system appropriately for the tag given as the

first argument. It uses the styles list-colors,

list-packed, list-rows-first, last-prompt, accept-exact,

menu and force-list.

The optional group supplies the name of the group in which the matches will be placed. If it is not given, the tag is used as the group name.

This function is called automatically from _description and

hence is not normally called explicitly.

_store_cache cache_identifier params ...

This function, together with _retrieve_cache and

zsh 4.3.10 Last change: June 1, 2009 90 User Commands ZSHCOMPSYS(1)

_cache_invalid, implements a caching layer which can be used

in any completion function. Data obtained by costly opera-

tions are stored in parameters; this function then dumps the values of those parameters to a file. The data can then be

retrieved quickly from that file via _retrieve_cache, even

in different instances of the shell.

The cache_identifier specifies the file which the data

should be dumped to. The file is stored in a directory

specified by the cache-path style which defaults to

~/.zcompcache. The remaining params arguments are the parameters to dump to the file. The return status is zero if storage was successful. The

function will only attempt storage if the use-cache style is

set, so you can call this function without worrying about whether the user wanted to use the caching layer.

The completion function may avoid calling _retrieve_cache

when it already has the completion data available as parame-

ters. However, in that case it should call _cache_invalid to

check whether the data in the parameters and in the cache are still valid.

See the _perl_modules completion function for a simple exam-

ple of the usage of the caching layer.

_tags [ [ -C name ] tags ... ]

If called with arguments, these are taken to be the names of tags valid for completions in the current context. These

tags are stored internally and sorted by using the tag-order

style.

Next, _tags is called repeatedly without arguments from the

same completion function. This successively selects the first, second, etc. set of tags requested by the user. The return status is zero if at least one of the tags is

requested and non-zero otherwise. To test if a particular

tag is to be tried, the _requested function should be called

(see above).

If `-C name' is given, name is temporarily stored in the

argument field (the fifth) of the context in the curcontext

parameter during the call to _tags; the field is restored on

exit. This allows _tags to use a more specific context

without having to change and reset the curcontext parameter (which has the same effect).

_values [ -O name ] [ -s sep ] [ -S sep ] [ -wC ] desc spec ...

This is used to complete arbitrary keywords (values) and their arguments, or lists of such combinations. zsh 4.3.10 Last change: June 1, 2009 91 User Commands ZSHCOMPSYS(1)

If the first argument is the option `-O name', it will be

used in the same way as by the _arguments function. In

other words, the elements of the name array will be passed to compadd when executing an action.

If the first argument (or the first argument after `-O

name') is `-s', the next argument is used as the character

that separates multiple values. This character is automati-

cally added after each value in an auto-removable fashion

(see below); all values completed by `_values -s' appear in

the same word on the command line, unlike completion using

_arguments. If this option is not present, only a single

value will be completed per word.

Normally, _values will only use the current word to deter-

mine which values are already present on the command line

and hence are not to be completed again. If the -w option

is given, other arguments are examined as well.

The first non-option argument is used as a string to print

as a description before listing the values. All other arguments describe the possible values and their arguments in the same format used for the description of

options by the _arguments function (see above). The only

differences are that no minus or plus sign is required at the beginning, values can have only one argument, and the

forms of action beginning with an equal sign are not sup-

ported. The character separating a value from its argument can be

set using the option -S (like -s, followed by the character

to use as the separator in the next argument). By default the equals sign will be used as the separator between values and arguments. Example:

_values -s , 'description' \

'*foo[bar]' \ '(two)*one[number]:first count:' \ 'two[another number]::second count:(1 2 3)' This describes three possible values: `foo', `one', and `two'. The first is described as `bar', takes no argument and may appear more than once. The second is described as `number', may appear more than once, and takes one mandatory argument described as `first count'; no action is specified, so it will not be completed. The `(two)' at the beginning says that if the value `one' is on the line, the value `two' will no longer be considered a possible completion. Finally, the last value (`two') is described as `another zsh 4.3.10 Last change: June 1, 2009 92 User Commands ZSHCOMPSYS(1) number' and takes an optional argument described as `second count' for which the completions (to appear after an `=')

are `1', `2', and `3'. The _values function will complete

lists of these values separated by commas.

Like _arguments, this function temporarily adds another con-

text name component to the arguments element (the fifth) of the current context while executing the action. Here this name is just the name of the value for which the argument is completed. The style verbose is used to decide if the descriptions for the values (but not those for the arguments) should be printed.

The associative array val_args is used to report values and

their arguments; this works similarly to the opt_args asso-

ciative array used by _arguments. Hence the function cal-

ling _values should declare the local parameters state,

line, context and val_args:

local context state line

typeset -A val_args

when using an action of the form `->string'. With this

function the context parameter will be set to the name of the value whose argument is to be completed.

Note also that _values normally adds the character used as

the separator between values as an auto-removable suffix

(similar to a `/' after a directory). However, this is not

possible for a `->string' action as the matches for the

argument are generated by the calling function. To get the usual behaviour, the the calling function can add the

separator x as a suffix by passing the options `-qS x'

either directly or indirectly to compadd.

The option -C is treated in the same way as it is by _argu-

ments. In that case the parameter curcontext should be made local instead of context (as described above). ...

_wanted [ -x ] [ -C name ] [ -12VJ ] tag name descr command args

In many contexts, completion can only generate one particu-

lar set of matches, usually corresponding to a single tag. However, it is still necessary to decide whether the user requires matches of this type. This function is useful in such a case.

The arguments to _wanted are the same as those to

_requested, i.e. arguments to be passed to _description.

However, in this case the command is not optional; all the zsh 4.3.10 Last change: June 1, 2009 93 User Commands ZSHCOMPSYS(1) processing of tags, including the loop over both tags and tag labels and the generation of matches, is carried out

automatically by _wanted.

Hence to offer only one tag and immediately add the corresponding matches with the given description: local expl

_wanted tag expl 'description' \

compadd matches...

Note that, as for _requested, the command must be able to

accept options to be passed down to compadd.

Like _tags this function supports the -C option to give a

different name for the argument context field. The -x

option has the same meaning as for _description.

COMPLETION DIRECTORIES

In the source distribution, the files are contained in vari-

ous subdirectories of the Completion directory. They may

have been installed in the same structure, or into one sin-

gle function directory. The following is a description of the files found in the original directory structure. If you wish to alter an installed file, you will need to copy it to some directory which appears earlier in your fpath than the standard directory where it appears. Base The core functions and special completion widgets automatically bound to keys. You will certainly need most of these, though will probably not need to alter them. Many of these are documented above. Zsh Functions for completing arguments of shell builtin commands and utility functions for this. Some of these are also used by functions from the Unix directory. Unix Functions for completing arguments of external commands and suites of commands. They may need modifying for your system, although in many cases some attempt is made to decide which version of a command is present. For example, completion for the mount command tries to determine the system it is running on, while completion for many other utilities try to decide whether the GNU version of the command is in use, and hence whether the

--help option is supported.

X, AIX, BSD, ... Completion and utility function for commands available

only on some systems. These are not arranged hierarch-

ically, so, for example, both the Linux and Debian directories, as well as the X directory, may be useful zsh 4.3.10 Last change: June 1, 2009 94 User Commands ZSHCOMPSYS(1) on your system.

ATTRIBUTES

See attributes(5) for descriptions of the following attri-

butes:

_______________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE|

|____________________|__________________|_

| Availability | shell/zsh |

|____________________|__________________|_

| Interface Stability| External |

|____________________|_________________|

NOTES Source for zsh is available on http://opensolaris.org. zsh 4.3.10 Last change: June 1, 2009 95