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- 20 Completion System
20 Completion System
20.1 Description
This describes the shell code for the ‘new’ completion system, referred
to as compsys
. It is written in shell functions based on the features
described in the previous chapter, Completion
Widgets.
The features are contextual, sensitive to the point at which completion is started. Many completions are already provided. For this reason, a user can perform a great many tasks without knowing any details beyond how to initialize the system, which is described in Initialization.
The context that decides what completion is to be performed may be
- 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’;
- 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 system 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 The zsh/zutil
Module.
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 that to modify its behavior. The full
description of context handling, which determines how tags and other
elements of the context influence the behaviour of styles, is described
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 function should be called to produce the
completions, and calls it. The result is passed to one or more
completers, functions that implement individual completion strategies:
simple completion, error correction, completion with error correction,
menu selection, etc.
More generally, the shell functions contained in the completion system are of two types:
- those beginning ‘
comp
’ are to be called directly; there are only a few of these; - those beginning ‘
_
’ are called by the completion code. The shell functions of this set, which implement completion behaviour and may be bound to keystrokes, are referred to as ‘widgets’. These proliferate as new completions are required.
20.2 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 compinstall
can be run by a user to
configure various aspects of the completion system.
Usually, compinstall
will insert code into .zshrc
, although if
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.
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 directories from fpath
. Then it must be autoloaded
(‘autoload -U compinstall
’ is recommended). You can abort the
installation 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.
20.2.1 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 produce 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 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 remembered 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
root or by the current user. If such files or directories are found,
compinit
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 compinit
, 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
provides compatibility with bash’s
programmable 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.
20.2.2 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 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 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
name
... [-
{p
|P
}pattern
... [-N
name
... ] ]
The file will be made autoloadable and the function defined in it will be called when completingname
s, 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 commandcmd
, 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 setting 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 patterns. The options-p
and-P
are used to specify patterns 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 patterns. It is possible to toggle between the three options as many times as necessary. -
#compdef -k
style key-sequence
...
This option creates a widget behaving like the builtin widgetstyle
and binds it to the givenkey-sequence
s, if any. Thestyle
must be one of the builtin widgets that perform completion, namelycomplete-word
,delete-char-or-list
,expand-or-complete
,expand-or-complete-prefix
,list-choices
,menu-complete
,menu-expand-or-complete
, orreverse-menu-complete
. If thezsh/complist
module is loaded (see The zsh/complist Module) the widgetmenu-select
is also available.When one of the
key-sequence
s is typed, the function in the file will be invoked to generate the matches. Note that a key will not be re-bound if it already was (that is, was bound to something other thanundefined-key
). The widget created has the same name as the file and can be bound to any other keys usingbindkey
as usual. -
#compdef -K
widget-name
style
key-sequence
[name
style
seq
... ]
This is similar to-k
except that only onekey-sequence
argument may be given for eachwidget-name
style
pair. However, the entire set of three arguments may be repeated with a different set of arguments. Note in particular that thewidget-name
must be distinct in each set. If it does not begin with ‘_
’ this will be added. Thewidget-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 autoloading but are not otherwise treated specially. Typically they are to be called from within one of the completion functions. Anyoptions
supplied will be passed to theautoload
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.
The special contexts for which completion functions can be defined are:
-array-value-
The right hand side of an array-assignment (‘name``=(``...``)
’)
-brace-parameter-
The name of a parameter expansion within braces (‘${``...``}
’)
-assign-parameter-
The name of a parameter in an assignment, i.e. on the left hand side of
an ‘=
’
-command-
A word in command position
-condition-
A word inside a condition (‘[[``...``]]
’)
-default-
Any word for which no other completion is defined
-equal-
A word beginning with an equals sign
-first-
This is tried before any other completion function. The function called
may set the _compskip
parameter to one of various values: all
: no
further completion is attempted; a string containing the substring
patterns
: no pattern completion functions will be called; a string
containing default
: the function for the ‘-default-
’ context will
not be called, but functions defined for commands will be.
-math-
Inside mathematical contexts, such as ‘((``...``))
’
-parameter-
The name of a parameter expansion (‘$``...
’)
-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.
-value-
On the right hand side of an assignment.
Default implementations are supplied for each of these contexts. In most
cases the context -``context``-
is implemented by a corresponding
function _``context
, for example the context ‘-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 on the left hand side of the
assignment. In the case of elements of an associative array, for example
‘assoc=(key <TAB>
’, name
is expanded to ‘name``-``key
’. In certain
special contexts, such as completing after ‘make CFLAGS=
’, the
command
part gives the name of the command, here make
; otherwise 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=<TAB>
’, _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> <TAB>
’ 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.
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> <TAB>
’ complete files
matching ‘*.log
’.
20.2.3 Functions
The following function is defined by compinit
and may be called
directly.
-
compdef
[-ane
]function name
... [-
{p
|P
}pattern
... [-N
name
...]]
compdef -d
name
...
compdef -k
[-an
]function style key-sequence
[key-sequence
... ]
compdef -K
[-an
]function name style key-seq
[name style seq
... ]
The first form defines thefunction
to call for completion in the given contexts as described for the#compdef
tag above.Alternatively, all the arguments may have the form ‘
cmd``=``service
’. Hereservice
should already have been defined by ‘cmd1``=``service
’ lines in#compdef
files, as described above. The argument forcmd
will be completed in the same way asservice
.The
function
argument may alternatively be a string containing almost any shell code. If the string contains an equal sign, the above will take precedence. The option-e
may be used to specify the first argument is to be evaluated as shell code even if it contains an equal sign. The string will be executed using theeval
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 commandfoo
: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
name
s may also contain-p
,-P
and-N
options as described for the#compdef
tag. The effect on the argument list is identical, switching between definitions of patterns tried initially, patterns tried finally, and normal commands and contexts.The parameter
$_compskip
may be set by any function defined for a pattern context. If it is set to a value containing the substring ‘patterns
’ none of the pattern-functions will be called; if it is set to a value containing the substring ‘all
’, no other function will be called. Setting$_compskip
in this manner is of particular utility when using the-p
option, as otherwise the dispatcher will move on to additional functions (likely the default one) after calling the pattern-context one, which can mangle the display of completion possibilities if not handled properly.The form with
-k
defines a widget with the same name as thefunction
that will be called for each of thekey-sequence
s; 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 thestyle
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
, andreverse-menu-complete
, as well asmenu-select
if thezsh/complist
module is loaded. The option-n
prevents the key being bound if it is already to bound to something other thanundefined-key
.The form with
-K
is similar and defines multiple widgets based on the samefunction
, each of which requires the set of three argumentsname
,style
andkey-seq
uence, 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 thefunction
autoloadable, equivalent toautoload -U ``function
.
The function compdef
can be used to associate existing completion
functions with new commands. For example,
compdef _pids foo
uses the function _pids
to complete process IDs for the command foo
.
Note also the _gnu_generic
function described below, which can be used
to complete options for commands that understand the ‘-``-help
’
option.
20.3 Completion System Configuration
This section gives a short overview of how the completion system works, and then more detail on how users can configure how and when matches are generated.
20.3.1 Overview
When completion is attempted somewhere on the command line the
completion system begins building the context. The context represents
everything that the shell knows about the meaning of the command line
and the significance of the cursor position. 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).
The context starts out very generic ("we are beginning a completion") and becomes more specific as more is learned ("the current word is in a position that is usually a command name" or "the current word might be a variable name" and so on). Therefore the context will vary during the same call to the completion system.
This context information is condensed into a string consisting of multiple fields separated by colons, referred to simply as ‘the context’ in the remainder of the documentation. Note that a user of the completion system rarely needs to compose a context string, unless for example a new function is being written to perform completion for a new command. What a user may need to do is compose a style pattern, which is matched against a context when needed to look up context-sensitive options that configure the completion system.
The next few paragraphs explain how a context is composed within the
completion function suite. Following that is discussion of how styles
are defined. Styles determine such things as how the matches are
generated, similarly to shell options but with much more control. They
are defined with the zstyle
builtin command (The zsh/zutil
Module).
The context string always consists of a fixed set of fields, separated
by colons and with a leading colon before the first. Fields which are
not yet known are left empty, but the surrounding colons appear anyway.
The fields are always in the order
:completion:``function``:``completer``:``command``:``argument``:``tag
.
These have the following meaning:
- 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 widgets and ZFTP functions. - The
function
, if completion is called from a named widget rather than through the normal completion system. Typically this is blank, but it is set by special widgets such aspredict-on
and the various functions in theWidget
directory of the distribution to the name of that function, often in an abbreviated form. - The
completer
currently active, the name of the function 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 Control Functions for more information. - The
command
or a special-``context``-
, just at it appears following the#compdef
tag or thecompdef
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 thecvs
command sets this field tocvs-add
when completing arguments to theadd
subcommand. - The
argument
; this indicates which command line or option argument we are completing. For command arguments this generally takes the formargument-``n
, wheren
is the number of the argument, and for arguments to options the formoption-``opt``-``n
wheren
is the number of the argument to optionopt
. 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. - 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 completion 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 argument 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 Bindable Commands.
When looking up styles the completion system uses full context names, including the tag. Looking up the value of a style therefore consists of two things: the context, which is matched to the most specific (best fitting) style pattern, and the name of the style itself, which must be matched exactly. The following examples demonstrate that style patterns may be loosely defined for styles that apply broadly, or as tightly defined as desired for styles that apply in narrower circumstances.
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 functions 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 Completion
Widgets)). 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 ‘:completion::complete:::*’
), and longer patterns
are preferred over shorter patterns.
A good rule of thumb is that any completion style pattern that needs to
include more than one wildcard (*
) and that does not end in a tag
name, should include all six colons (:
), possibly surrounding
additional wildcards.
Style names like those of tags are arbitrary and depend on the completion function. However, the following two sections list some of the most common tags and styles.
20.3.2 Standard Tags
Some of the following are only used when looking up particular 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 particular 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 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 — local-directories
is used instead when
completing arguments of cd
and related builtin commands when the
cdpath
array is set
directory-stack
for entries in the directory stack
displays
for X display names
domains
for network domains
email-``plugin
for email addresses from the ‘_email-``plugin
’ backend of
_email_addresses
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 completing filenames
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 pattern 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
) — when the cdpath
array is unset,
directories
is used instead
manuals
for names of manual pages
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
completers 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
for names of directories found by searching the cdpath
array when
completing arguments of cd
and related builtin 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)
types
for types of whatever (e.g. address types for the xhost
command)
urls
used to look up the urls
and local
styles when completing 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 particular 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
20.3.3 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
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 normally be defined along the lines of:
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
immediately even if the command line contains some more partially 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’; otherwise the
completion system will be allowed to complete $foo
to $foobar
. If
the style is set to ‘continue
’, _expand
will add the expansion as a
match and the completion system will also be allowed to continue.
accept-exact-dirs
This is used by filename completion. Unlike accept-exact
it is a
boolean. By default, filename completion examines all components of a
path to see if there are completions of that component, even if the
component matches an existing directory. For example, when completion
after /usr/bin/
, the function examines possible completions to /usr
.
When this style is ‘true’, any prefix of a path that matches an existing
directory is accepted without any attempt to complete it further. Hence,
in the given example, the path /usr/bin/
is accepted immediately and
completion tried in that directory.
This style is also useful when completing after directories that
magically appear when referenced, such as ZFS .zfs
directories or
NetApp .snapshot
directories. When the style is set the shell does not
check for the existence of the directory within the parent directory.
If you wish to inhibit this behaviour entirely, set the
path-completion
style (see below) to ‘false’.
add-space
This style is used by the _expand
completer. If it is ‘true’ (the
default), a space will be inserted after all words resulting from the
expansion, or a slash in the case of directory names. If the value is
‘file
’, the completer will only add a space to names of existing
files. Either a boolean ‘true’ or the value ‘file
’ may be combined
with ‘subst
’, in which case the completer will not add a space to
words generated from the expansion of a substitution of the form
‘$(``...``)
’ or ‘${``...``}
’.
The _prefix
completer uses this style as a simple boolean value to
decide if a space should be inserted before the suffix.
ambiguous
This applies when completing non-final components of filename paths, in
other words those with a trailing slash. If it is set, the cursor is
left after the first ambiguous component, even if menu completion is in
use. The style is always tested with the paths
tag.
assign-list
When completing after an equals sign that is being treated as an
assignment, the completion system normally completes only one filename.
In some cases the value may be a list of filenames separated by colons,
as with PATH
and similar parameters. This style can be set to a list
of patterns matching the names of such parameters.
The default is to complete lists when the word on the line already contains a colon.
auto-description
If set, this style’s value will be used as the description for options
that are not described by the completion functions, but that have
exactly one argument. The sequence ‘%d
’ in the value will be replaced
by the description for this argument. Depending on personal preferences,
it may be useful to set this style to something like ‘specify: %d
’.
Note that this may not work for some commands.
avoid-completer
This is used by the _all_matches
completer to decide if the string
consisting of all matches should be added to the list currently being
generated. Its value is a list of names of completers. If any of these
is the name of the completer that generated the matches in this
completion, the string will not be added.
The default value for this style is ‘_expand _old_list _correct _approximate
’, i.e. it contains the completers for which a string with
all matches will almost never be wanted.
cache-path
This style defines the path where any cache files containing dumped
completion data are stored. It defaults to ‘$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 generate matches suffers problems
such as being slow or, as in the case of make
can potentially cause
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 execute. 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 function 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
command.
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 complete.
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 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 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 preceding -``-
on the command
line.
completer
The strings given as the value of this style provide the names of the completer functions to use. The available completer functions are described in Control Functions.
Each string may be either the name of a completer function or a string
of the form ‘function``:``name
’. In the first case the completer
field of the context will contain 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 completer 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
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 $fignore
array and then without ignoring matches.
condition
This style is used by the _list
completer function to decide if
insertion of matches should be delayed unconditionally. The default is
‘true’.
delimiters
This style is used when adding a delimiter for use with history
modifiers or glob qualifiers that have delimited arguments. It is an
array of preferred delimiters to add. Non-special characters are
preferred as the completion system may otherwise become confused. The
default list is :
, +
, /
, -
, %
. The list may be empty to force
a delimiter to be typed.
disabled
If this is set to ‘true’, the _expand_alias
completer and bindable
command will try to expand disabled aliases, too. The default is
‘false’.
domains
A list of names of network domains for completion. If this is not set,
domain names will be taken from the file /etc/resolv.conf
.
environ
The environ style is used when completing for ‘sudo
’. It is set to an
array of ‘VAR``=``value
’ assignments to be exported into the local
environment before the completion for the target command is invoked.
zstyle ':completion:*:sudo::' environ \
PATH="/sbin:/usr/sbin:$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 partially 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 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 completed 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 context when
specifying fake strings. Note that the styles fake-files
and
fake-parameters
provide additional 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 completely by setting the ignored patterns to
‘*
’.
The following shows a way of supplementing any tag with arbitrary data,
but having it behave for display purposes 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 completion 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
completing 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 quoted with a backslash to be treated literally.
This can be useful on systems that support special file systems whose
top-level pathnames can not be listed or generated with glob patterns
(but see accept-exact-dirs
for a more general way of dealing with this
problem). It can also be used for directories for which one does not
have read permission.
The pattern form can be used to add a certain ‘magic’ entry to all directories on a particular file 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
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 circumstances, 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.
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 calling _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 tag
s of all strings in the value will be offered by _files
and
used when looking up other styles. Any tag
s 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 completion function. If the description given here
contains itself a ‘%d
’, that is replaced with the description 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'
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.
file-split-chars
A set of characters that will cause all file completions for the given
context to be split at the point where any of the characters occurs. A
typical use is to set the style to :
; then everything up to and
including the last :
in the string so far is ignored when completing
files. As this is quite heavy-handed, it is usually preferable to update
completion functions for contexts where this behaviour is useful.
filter
The ldap
plugin of email address completion (see _email_addresses
)
uses this style 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, normally the list is only shown if there are at least two
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 output attribute sequences
understood by compadd -X
(see Completion
Widgets).
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 additional
‘%
’-sequences. These are described for the completer 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 warnings
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 specifiers with ‘%d
’
and similar escape sequences. This is handled by the zformat
builtin
command from the zsh/zutil
module, see The zsh/zutil
Module.
glob
This is used by the _expand
completer. If it is set to ‘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 commands, 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
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 completion. If it is
set to ‘true’, none of the words that are already on the line will be
considered as possible 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
’, all words on the line except for the current one will
be excluded from the possible completions.
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.
ignore-parents
The style is tested without a tag by the function completing 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 afterfoo/../
, the directoryfoo
will not be considered a valid completion. -
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 directory.
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. Completion 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 completers 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
This style is used by the _all_matches
completer to decide whether to
insert the list of all matches unconditionally 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 possible 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 command 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 completion 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 starting completion when there is unprocessed input pending.
If a val
is given, completion 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 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 completer 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 unambiguously.
gain-privileges
If set to true
, this style enables the use of commands like sudo
or
doas
to gain extra privileges when retrieving information for
completion. This is only done when a command such as sudo
appears on
the command-line. To force the use of, e.g. sudo
or to override any
prefix that might be added due to gain-privileges
, the command
style
can be used with a value that begins with a hyphen.
keep-prefix
This style is used by the _expand
completer. If it is ‘true’, the
completer will try to keep a prefix containing 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 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
bindable command. If
it is set to ‘true’ it has no effect. If it is set to ‘false’ matches
will not be listed. This overrides the setting of the options
controlling listing behaviour, in particular AUTO_LIST
. The context
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 zsh/complist
Module, 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)
’ syntax allowed by the ZLS_COLORS
and
ZLS_COLOURS
parameters 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
command 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 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 zsh/complist
Module). 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 otherwise. 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 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 pathname components, all ambiguous components will be shown. Otherwise, completion stops at the first ambiguous component.
list-separator
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 file 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 placed before any match specifications given by
the matcher-list
style so can override them via the use of an x:
specification. The value should be in the form described in Completion
Matching Control.
For examples of this, see the description of the tag-order
style.
For notes comparing the use of this and the matcher-list
style, see
under the description of the tag-order
style.
matcher-list
This style can be set to a list of match specifications that are to be applied everywhere. Match specifications are described in Completion Matching Control. 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:
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. This applies only to
completers that override the global matcher-list, which as of this
writing includes only _prefix
and _ignored
. For example, to use the
completers _complete
and _prefix
but allow case-insensitive
completion only 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 correction, 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 specification 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 be 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 performance. As a rough rule of thumb, hand, putting
multiple space-separated values into the same string does not have an
appreciable impact on performance.
If there is no current matcher or it is empty, and the option
NO_CASE_GLOB
is in effect, the matching for files is performed
case-insensitively in any case. However, any matcher must explicitly
specify case-insensitive matching if that is required.
For notes comparing the use of this and the matcher
style, see under
the description of the tag-order
style.
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 completions 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 completion 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 defined for the
current completion menu completion will be used. The value for a
specific tag will take precedence 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 completion 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 following values may appear either
alongside or instead of the values above.
If the value contains the string ‘select
’, menu selection 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 there are a certain
number of matches or the list of 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
zsh/complist Module 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 listing 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 corrections 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.
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 generated 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 command; this is the behaviour without the
_oldlist
completer.
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 corrections.
original
This is used by the _approximate
and _correct
completers 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 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.
path-completion
This is used by filename completion. By default, filename completion
examines all components of a path to see if there are completions of
that component. For example, /u/b/z
can be completed to
/usr/bin/zsh
. Explicitly setting this style to ‘false’ inhibits this
behaviour for path components up to the /
before the cursor; this
overrides the setting of accept-exact-dirs
.
Even with the style set to ‘false’, it is still possible to complete
multiple paths by setting the option COMPLETE_IN_WORD
and moving the
cursor back to the first component in the path to be completed. For
example, /u/b/z
can be completed to /usr/bin/zsh
if the cursor is
after the /u
.
pine-directory
If set, specifies the directory containing PINE mailbox files. There is no default, since recursively searching 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 common 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 style is also relevant 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.
The style is applicable to the options
, signals
, jobs
,
functions
, and parameters
completion tags.
For command options, this means that the initial ‘-
’, ‘+
’, or
‘-``-
’ must be typed explicitly before option names will be
completed.
For signals, an initial ‘-
’ is required before signal names will be
completed.
For jobs, an initial ‘%
’ is required before job names will be
completed.
For function and parameter names, an initial ‘_
’ or ‘.
’ is required
before function or parameter names starting with those characters will
be completed.
The default value for this style is ‘false’ for function
and
parameter
completions, and ‘true’ otherwise.
preserve-prefix
This style is used when completing path names. Its value should be a
pattern matching an initial prefix of 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 single 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 has been found, or max
words have been tried.
The default is to complete all words from the history at once.
recursive-files
If this style is set, its value is an array of patterns to be tested
against ‘$PWD/
’: note the trailing slash, which allows directories in
the pattern to be delimited unambiguously by including slashes on both
sides. If an ordinary file completion fails and the word on the command
line does not yet have a directory part to its name, the style is
retrieved using the same tag as for the completion just attempted, then
the elements tested against $PWD/
in turn. If one matches, then the
shell reattempts completion by prepending the word on the command line
with each directory in the expansion of **/*(/)
in turn. Typically the
elements of the style will be set to restrict the number of directories
beneath the current one to a manageable number, for example
‘*/.git/*
’.
For example,
zstyle ':completion:*' recursive-files '*/zsh/*'
If the current directory is /home/pws/zsh/Src
, then zle_tr
TAB can
be completed to Zle/zle_tricky.c
.
regular
This style is used by the _expand_alias
completer and bindable
command. If set to ‘true’ (the default), regular aliases will be
expanded but only in command position. 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 position.
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
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 selection (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 completing words for the dict
command. It allows words from different dictionary databases to be added
separately. The default for this style is ‘false’.
show-ambiguity
If the zsh/complist
module is loaded, this style can be used to
highlight the first ambiguous character in completion lists. The value
is either a color indication such as those supported by the
list-colors
style or, with a value of ‘true’, a default of underlining
is selected. The highlighting is only applied if the completion display
strings correspond to the actual matches.
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 completion 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 string are both added as matches and menu completion is
started, making it easy to select either of them.
sort
This allows the standard ordering of matches to be overridden.
If its value is ‘true
’ or ‘false
’, sorting is enabled or disabled.
Additionally the values associated with the ‘-o
’ option to compadd
can also be listed: match
, nosort
, numeric
, reverse
. 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.
In many cases where a calling widget explicitly selects a particular
ordering in lieu of the default, a value of ‘true
’ is not honoured. An
example of where this is not the case is for command history where the
default of sorting matches chronologically 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 consists only of a path beginning
with ‘../
’. Otherwise the value is ‘false’.
zstyle -e ':completion:*' special-dirs \
'[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'
squeeze-slashes
If set to ‘true’, sequences of slashes in filename paths (for example in
‘foo//bar
’) will be treated as a single slash. This is the usual
behaviour of UNIX paths. However, by default the file completion
function behaves as if there were a ‘*
’ between the slashes.
stop
If set to ‘true’, the _history_complete_word
bindable command will
stop once when reaching the beginning or end of the history. Invoking
_history_complete_word
will then wrap around to the opposite end of
the history. If this style is set to ‘false’ (the default),
_history_complete_word
will loop immediately as in a menu completion.
strip-comments
If set to ‘true’, this style causes non-essential comment text to be
removed from completion matches. Currently it is only used when
completing e-mail addresses where it removes any display name from the
addresses, cutting them down to plain user@host
form.
subst-globs-only
This is used by the _expand
completer. If it is set to ‘true’, the
expansion will only be used if it resulted from globbing; hence, if
expansions resulted from the use of the substitute
style described
below, but these were not further changed by globbing, the expansions
will be rejected.
The default for this style is ‘false’.
substitute
This boolean style controls whether the _expand
completer will first
try to expand all substitutions in the string (such as ‘$(``...``)
’
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 characters 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:
zstyle ':completion:*:complete:-command-:*:*' tag-order \
'commands functions'
specifies that completion in command position first offers external commands and shell functions. Remaining 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 generated. Normally all tags not explicitly selected are tried last if the specified tags fail to generate any matches. This means that a single value consisting only of a single hyphen turns off completion. -
!
tags
...
A string starting with an exclamation mark specifies 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 andlabel
is an arbitrary name. Matches are generated as normal but the namelabel
is used in contexts instead oftag
. This is not useful in words starting with!
.If the
label
starts with a hyphen, thetag
is prepended to thelabel
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, butdescription
will replace the ‘%d
’ in the value of theformat
style instead of the default description supplied by the completion function. Spaces in the description must be quoted with a backslash. A ‘%d
’ appearing indescription
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.
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 completion 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 function 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 different 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}'
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
builtin command to
specify conditions for the use of particular 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 Completion
Widgets 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 function 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 urls
tag by functions 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 newlines).
Finally, if the only string in the value names a directory, the
directory hierarchy rooted at this directory 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 hierarchy can descend as
deep as necessary.
For example,
zstyle ':completion:*' urls ~/.urls
mkdir -p ~/.urls/ftp/ftp.zsh.org/pub
allows completion of all the components of the URL ‘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
functions). 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 completion 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 transition 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
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).
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 completed; 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 commands 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 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.
20.4 Control Functions
The initialization script compinit
redefines all the widgets which
perform completion to call the supplied widget function
_main_complete
. This function acts as a wrapper calling 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 completer
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 distribution,
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 completers it must appear as the first
completer in the list. The list of all matches is affected by the
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 Filename Generation
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 original string. The
format
style for the former may contain the additional sequences
‘%e
’ and ‘%o
’ which will be replaced by the number of errors
accepted to generate the corrections and the original string,
respectively.
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 completions with two errors will be shown, and so on. It
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, especially 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 CURSOR
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.
_canonical_paths
[ -A
var
] [ -N
] [ -MJV12nfX
] tag
descr
[ paths
... ]
This completion function completes all paths given to it, and also tries
to offer completions which point to the same file as one of the paths
given (relative path when an absolute path is given, and vice versa;
when ..
’s are present in the word to be completed; and some paths got
from symlinks).
-A
, if specified, takes the paths from the array variable specified.
Paths can also be specified on the command line as shown above. -N
, if
specified, prevents canonicalizing the paths given before using them for
completion, in case they are already so. The options -M
, -J
, -V
,
-1
, -2
, -n
, -F
, -X
are passed to compadd
.
See _description
for a description of tag
and descr
.
_cmdambivalent
Completes the remaining positional arguments as an external command. The
external command and its arguments are completed as separate arguments
(in a manner appropriate for completing /usr/bin/env
) if there are two
or more remaining positional arguments on the command line, and as a
quoted command string (in the manner of system(...)
) otherwise. See
also _cmdstring
and _precommand
.
This function takes no arguments.
_cmdstring
Completes an external command as a single argument, as for
system(...)
.
_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 handled specifically. These are all mentioned above
as possible arguments to the #compdef
tag.
Before trying to find a function for a specific context, _complete
checks if the parameter ‘compcontext
’ is set. Setting ‘compcontext
’
allows the usual completion dispatching to be overridden which is useful
in places such as a function that uses vared
for input. If 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
context named -command-line-
that completes whole command lines
(commands and their arguments). This is not used by the completion
system itself but is nonetheless handled 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 correcting 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 before it. Using it
after the _approximate
completer is useless since _approximate
will
at least generate the corrected strings generated by the _correct
completer — and probably more.
_expand
This completer function does not really perform completion, 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
completer 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 expansions 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 controlled 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 Bindable Commands.
_extensions
If the cursor follows the string ‘*.
’, filename extensions are
completed. The extensions are taken from files in current directory or a
directory specified at the beginning of the current word. For exact
matches, completion continues to allow other completers such as
_expand
to expand the pattern. The standard add-space
and
prefix-hidden
styles are observed.
_external_pwds
Completes current directories of other zsh processes belonging to the current user.
This is intended to be used via _generic
, bound to a custom key
combination. Note that pattern matching is enabled so matching is
performed similar to how it works with the _match
completer.
_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 command, see Bindable
Commands and Completion System
Configuration.
_ignored
The ignored-patterns
style can be set to a list of patterns 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
completer. 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 Completion
System Configuration.
_match
This completer is intended to be used after the _complete
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 completion 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
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 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 completions which may have been generated
by a special completion (i.e. a separately-bound completion command). It
allows the ordinary completion keys to continue 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 completers
before any of the widgets which generate matches. It uses two styles:
old-list
and old-menu
, see Completion System
Configuration.
_precommand
Complete an external command in word-separated arguments, as for exec
and /usr/bin/env
.
_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 completers 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
_prefix
completer itself. Furthermore, if this completer appears more
than once in the list of completers only those completers not already
tried by the last invocation 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
completer 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
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
completer 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 inhash
, 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 arrayreply
to a list of expansions. Optionally, it can setREPLY
to a word that will be used as a description for the set of expansions. The return status of the function is irrelevant.
20.5 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, _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 bindings,
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
completer.
_expand_alias
(^Xa
)
This function can be used as a completer and as a bindable 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
disabled
.
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
)
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 function
field of the context and call the
completion system. 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 completion 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 N
th 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
invocations 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 possibilities 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 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 completion. 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 executed 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 incomplete; it depends on the information available from the completion functions called, which in turn is determined 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 function, 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
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
generate 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 generic 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.
20.6 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.
_absolute_command_paths
This function completes external commands as absolute paths (unlike
_command_names -e
which completes their basenames). It takes no
arguments.
_all_labels
[ -x
] [ -12VJ
] tag
name
descr
[ command
arg
... ]
This is a convenient interface to the _next_label
function 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 arg
s
passed to the command
. Normally, they are put directly after the
command
, but if one of the arg
s 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
[ -O
name
] [ -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 spec
s which are of the form:
‘tag``:``descr``:``action
’. The tag
s are offered using _tags
and
if the tag is requested, the action
is executed with the given
description descr
. The action
s are those accepted by the
_arguments
function (described below), excluding the ‘->``state
’ and
‘=``...
’ forms.
For example, the action
may be a simple function call:
_alternative \
'users:user:_users' \
'hosts:host:_hosts'
offers usernames and hostnames as possible matches, generated by the
_users
and _hosts
functions respectively.
Like _arguments
, this function 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
.
The option ‘-O
name
’ is 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.
Like _tags
this function supports the -C
option to give a different
name for the argument context field.
_arguments
[ -nswWCRS
] [ -A
pat
] [ -O
name
] [
-M
matchspec
]
[ :
] spec
...
_arguments
[ opt
... ] -``-
[ -l
] [ -i
pats
] [
-s
pair
]
[ helpspec
...]
This function can be used to give a complete specification for completion for a command whose arguments follow standard UNIX option and argument conventions.
Options Overview
Options to _arguments
itself must be in separate words, i.e. -s -w
,
not -sw
. The options are followed by spec
s that describe options and
arguments of the analyzed command. To avoid ambiguity, all options to
_arguments
itself may be separated from the spec
forms by a single
colon.
The ‘-``-
’ form is used to intuit spec
forms from the help output of
the command being analyzed, and is described in detail below. The opts
for the ‘-``-
’ form are otherwise the same options as the first form.
Note that ‘-s
’ following ‘-``-
’ has a distinct meaning from ‘-s
’
preceding ‘-``-
’, and both may appear.
The option switches -s
, -S
, -A
, -w
, and -W
affect how
_arguments
parses the analyzed command line’s options. These switches
are useful for commands with standard argument parsing.
The options of _arguments
have the following meanings:
-
-n
With this option,_arguments
sets the parameterNORMARG
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. -
-s
Enable option stacking for single-letter options, whereby multiple single-letter options may be combined into a single word. For example, the two options ‘-x
’ and ‘-y
’ may be combined into a single word ‘-xy
’. By default, every word corresponds to a single option name (‘-xy
’ is a single option named ‘xy
’).Options beginning with a single hyphen or plus sign are eligible for stacking; words beginning with two hyphens are not.
Note that
-s
after-``-
has a different meaning, which is documented in the segment entitled ‘Derivingspec
forms from the help output’. -
-w
In combination with-s
, allow option stacking even if one or more of the options take arguments. For example, if-x
takes an argument, with no-s
, ‘-xy
’ is considered as a single (unhandled) option; with-s
,-xy
is an option with the argument ‘y
’; with both-s
and-w
,-xy
is the option-x
and the option-y
with arguments to-x
(and to-y
, if it takes arguments) still to come in subsequent words. -
-W
This option takes-w
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. -
-C
Modify thecurcontext
parameter for an action of the form ‘->``state
’. This is discussed in detail below. -
-R
Return status 300 instead of zero when a$state
is to be handled, in the ‘->``string
’ syntax. -
-S
Do not complete options after a ‘-``-
’ appearing on the line, and ignore the ‘-``-
’. For example, with-S
, in the linefoobar -x -- -y
the ‘
-x
’ is considered an option, the ‘-y
’ is considered an argument, and the ‘-``-
’ is considered to be neither. -
-A
pat
Do not complete options after the first non-option argument on the line.pat
is 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 theoptspec
s, the form is ‘-A "-*"
’. -
-O
name
Pass the elements of the arrayname
as arguments to functions called to executeaction
s. This is discussed in detail below. -
-M
matchspec
Use the match specificationmatchspec
for completing option names and values. The defaultmatchspec
allows partial word completion after ‘_
’ and ‘-
’, such as completing ‘-f-b
’ to ‘-foo-bar
’. The defaultmatchspec
is:r:|[_-]=* r:|=*
spec
s: overview
Each of the following forms is a spec
describing individual sets of
options or arguments on the command line being analyzed.
-
n``:``message``:``action
n``::``message``:``action
This describes then
’th normal argument. Themessage
will be printed above the matches generated and theaction
indicates what can be completed in this position (see below). If there are two colons before themessage
the argument is optional. If themessage
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 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 completed in this fashion.With two colons before the
message
, thewords
special array and theCURRENT
special parameter are modified to refer only to the normal arguments when theaction
is executed or evaluated. With three colons before themessage
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.The following forms are available for the initial
optspec
, whether or not the option has arguments.-
*``optspec
Hereoptspec
is one of the remaining forms below. This indicates the followingoptspec
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 theoptspec
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 ‘-foo``arg
’. -
-``optname``+
The first argument may appear immediately afteroptname
in the same word, or may appear as a separate word after the option. For example, ‘-foo+:``...
’ specifies that the completed option and argument will look like either ‘-foo``arg
’ 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. -
optspec``[``explanation``]
An explanation string may be appended to any of the preceding forms ofoptspec
by enclosing it in brackets, as in ‘-q[query operation]
’.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 thisoptspec
, the value of the style is displayed, with any appearance of the sequence ‘%d
’ in it replaced by themessage
of the firstoptarg
that follows theoptspec
; see below.
It is possible for options with a literal ‘
+
’ or ‘=
’ to appear, but that character must be quoted, for example ‘-\+
’.Each
optarg
following anoptspec
must take one of the following forms:-
:``message``:``action
::``message``:``action
An argument to the option;message
andaction
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 lastoptarg
for an option taking multiple arguments may be given in this form. If thepattern
is empty (i.e.:*:
), all the remaining words on the line are to be completed as described by theaction
; otherwise, all the words up to and including a word matching thepattern
are to be completed using theaction
.Multiple colons are treated as for the ‘
*:``...
’ forms for ordinary arguments: when themessage
is preceded by two colons, thewords
special array and theCURRENT
special parameter are modified during the execution or evaluation of theaction
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 description.
-
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 arguments 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-) arguments; 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 completed.
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
’.
spec
s: actions
In each of the forms above the action
determines how completions
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 functions called to execute action
s will be called with the
elements of the array named by the ‘-O
name
’ option as arguments.
This can be used, for example, to pass the same set of options for the
compadd
builtin to all action
s.
The forms for action
are as follows.
-
This is useful where an argument is required but it is not possible or desirable to generate matches for it. Themessage
will be displayed but no completions listed. Note that even in this case the colon at the end of themessage
is needed; it may only be omitted when neither amessage
nor anaction
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 descriptions if the
description
style is set with thevalues
tag in the context. -
->``string
In this form,
_arguments
processes the arguments and options and then returns control to the calling function with parameters set to indicate the state of processing; 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
encountersaction
in the ‘->``string
’ format, it will strip all leading and trailing whitespace fromstring
and set the arraystate
to the set of allstring
s for which an action is to be performed. The elements of the arraystate_descr
are assigned the correspondingmessage
field from eachoptarg
containing such anaction
.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. However, 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
$state
and$state_descr
,_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 asPREFIX
andwords
. This gives the calling function the choice of resetting these parameters or propagating changes in them.A function calling
_arguments
with at least one action containing a ‘->``string
’ must therefore declare appropriate local parameters:local context state state_descr line typeset -A opt_args
to prevent
_arguments
from altering the global environment. -
{``eval-string``}
A string in braces is evaluated as shell code to generate 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 theaction
starts with ‘=
’ (an equals sign followed by a space),_arguments
will insert the contents of theargument
field of the current context as the new first element in thewords
special array and increment the value of theCURRENT
special parameter. This has the effect of inserting a dummy word onto the completion command line while not changing the point at which completion 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 anaction
itself causes_arguments
on a restricted range; it is necessary 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 theaction
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 theaction
and hence may be referred to inside it, typically in an expansion of the form ‘$expl[@]
’ which preserves empty elements of the array.
During the performance of the action the array ‘line
’ will be set to
the normal arguments from the command line, i.e. the words from the
command line after the command name 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 and backslashes in the original arguments are
preceded 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 $state
. Each string of
the form ‘option``-opt``-``n
’ for the n
’th argument of the option
-opt
, or a string of the form ‘argument-``n
’ for the n
’th
argument. For ‘rest’ arguments, that is those in the list at the end not
handled by position, n
is the string ‘rest
’. For example, when
completing the argument of the -o
option, the name is ‘option-o-1
’,
while for the second normal (non-option-) argument it is ‘argument-2
’.
Furthermore, during the evaluation of the action
the context name in
the curcontext
parameter is altered to append the same string that is
stored in the context
parameter.
The option -C
tells _arguments
to modify the curcontext
parameter
for an action of the form ‘->``state
’. This is the standard parameter
used to keep track of the current context. Here it (and not the
context
array) should be made local to the calling function to avoid
passing back the modified value and should be initialised to the current
value at the start of the function:
local curcontext="$curcontext"
This is useful where it is not possible for multiple states to be valid together.
Grouping Options
Options can be grouped to simplify exclusion lists. A group is
introduced with ‘+
’ followed by a name for the group in the subsequent
word. Whole groups can then be referenced in an exclusion list or a
group name can be used to disambiguate between two forms of the same
option. For example:
_arguments \
'(group2--x)-a' \
+ group1 \
-m \
'(group2)-n' \
+ group2 \
-x -y
If the name of a group is specified in the form ‘(``name``)
’ then only
one value from that group will ever be completed; more formally, all
specifications are mutually exclusive to all other specifications in
that group. This is useful for defining options that are aliases for
each other. For example:
_arguments \
-a -b \
+ '(operation)' \
{-c,--compress}'[compress]' \
{-d,--decompress}'[decompress]' \
{-l,--list}'[list]'
If an option in a group appears on the command line, it is stored in the
associative array ‘opt_args
’ with ’group``-``option
’ as a key. In
the example above, a key ‘operation–c
’ is used if the option ‘-c
’ is
present on the command line.
Specifying Multiple Sets of Arguments
It is possible to specify multiple sets of options and arguments with the sets separated by single hyphens. This differs from groups in that sets are considered to be mutually exclusive of each other.
Specifications before the first set and from any group are common to all sets. 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. However, after ‘-a
’ both sets will still be
considered valid.
As for groups, the name of a set may appear in exclusion lists, either alone or preceding a normal option or argument specification.
The completion code has to parse the command line separately for each
set. This can be slow so sets 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 remaining
arguments as described by the optarg
definitions.
Deriving spec
forms from the help output
The option ‘-``-
’ allows _arguments
to work out the names of long
options that support the ‘-``-help
’ option which is standard 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 commands 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 helpspec
of the form
‘pattern``:``message``:``action
’; note that other _arguments
spec
forms 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 specifiers. The special case of ‘*:
’ means
both message
and action
are empty, which has the effect of causing
options having no description in the help output to be ordered in
listings ahead of options that have a description.
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
’.
Note also that _arguments
tries to find out automatically if the
argument for an option is optional. This can be specified explicitly by
doubling the colon before the message
.
If the pattern
ends in ‘(-)
’, this will be 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 normal specification defined with
the form ‘=-
’.
By default, the command (with the option ‘–help
’) is run after
resetting all the locale categories (except for LC_CTYPE
) to ‘C
’. If
the localized help output is known to work, the option ‘-l
’ can be
specified after the ‘_arguments -``-
’ so that the command is run in
the current locale.
The ‘_arguments -``-
’ can be followed by the option ‘-i
patterns
’
to give patterns for options which are not to be completed. 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. The pair
consists of a list of
alternating patterns and corresponding replacements, enclosed in parens
and quoted so that it forms a single argument word in the _arguments
call.
For example, some configure
-script help output describes options only
as ‘-``-enable-foo
’, but the script also accepts the negated form
‘-``-disable-foo
’. To allow completion of the second form:
_arguments -- -s "((#s)--enable- --disable-)"
Miscellaneous notes
Finally, note that _arguments
generally expects to be the primary
function handling any completion for which it is used. It may have side
effects which change the treatment of any matches added by other
functions called after it. To combine _arguments
with other functions,
those functions should be called either before _arguments
, as an
action
within a spec
, or in handlers for ‘->``state
’ actions.
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 ‘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 completions.
_cache_invalid
cache_identifier
This function returns status zero if the completions cache corresponding
to the given cache identifier needs rebuilding. It determines this by
looking up the cache-policy
style for the current context. This should
provide a function 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"(Nm+7) )
(( $#oldp ))
}
_call_function
return
name
[ arg
... ]
If a function name
exists, it is called with the arguments arg
s. The
return
argument gives the name of a parameter in which the return
status from the function name
should be stored; 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
[ -l
] [ -p
] 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 string
s from the call to _call_program
, or from the style if
set, are concatenated with spaces between them and the resulting string
is evaluated. The return status is the return status of the command
called.
By default, the command is run in an environment where all the locale
categories (except for LC_CTYPE
) are reset to ‘C
’ by calling the
utility function _comp_locale
(see below). If the option ‘-l
’ is
given, the command is run with the current locale.
If the option ‘-p
’ is supplied it indicates that the command output is
influenced by the permissions it is run with. If the gain-privileges
style is set to true, _call_program
will make use of commands such as
sudo
, if present on the command-line, to match the permissions to
whatever the final command is likely to run under. When looking up the
gain-privileges
and command
styles, the command component of the
zstyle context will end with a slash (‘/
’) followed by the command
that would be used to gain privileges.
_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.
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
field
s 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 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 example ‘-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 underscore 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.
_command_names
[ -e
| -
]
This function completes words that are valid at command position: names
of aliases, builtins, hashed commands, functions, and so on. With the
-e
flag, only hashed commands are completed. The -
flag is ignored.
_comp_locale
This function resets all the locale categories other than LC_CTYPE
to
‘C
’ so that the output from external commands can be easily analyzed
by the completion system. LC_CTYPE
retains the current value (taking
LC_ALL
and LANG
into account), ensuring that non-ASCII characters in
file names are still handled properly.
This function should normally be run only in a subshell, because the new
locale is exported to the environment. Typical usage would be
‘ $(_comp_locale; ``command
...)
’.
_completers
[ -p
]
This function completes names of completers.
-p
Include the leading underscore (‘_
’) in the matches.
_describe
[-12JVx
] [ -oO
| -t
tag
] descr
name1
[
name2
] [ opt
... ]
[ -``-
name1
[ name2
] [ opt
... ] ... ]
This function associates completions with descriptions. Multiple groups
separated by -``-
can be supplied, potentially with different
completion options opt
s.
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
array name1
contains the possible completions with their descriptions
in the form ‘completion``:``description
’. Any literal colons in
completion
must be quoted with a backslash. If a name2
is given, it
should have the same number of elements as name1
; in this case the
corresponding elements are added as possible completions instead of the
completion
strings from name1
. The completion list will retain the
descriptions from name1
. Finally, a set of completion 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
’.
The options -1
, -2
, -J
, -V
, -x
are passed to _next_label
.
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 compadd
. It is buried inside
many of the higher level completion 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
, ignore-line
,
ignored-patterns
, group-name
and sort
. 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.
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 spec
s 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 completion system use
a similar format; this ensures that user-specified styles are correctly
passed down to the builtins which implement the internals of completion.
_dir_list
[ -s
sep
] [ -S
]
Complete a list of directory names separated by colons (the same format
as $PATH
).
-
-s
sep
Usesep
as separator between items.sep
defaults to a colon (‘:
’). -
-S
Addsep
instead of slash (‘/
’) as an autoremoveable suffix.
_dispatch
context string
...
This sets the current context to context
and looks for completion
functions to handle this context by hunting through the list of command
names or special contexts (as described above for compdef
) given as
string
s. The first completion 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 completion 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 the $curcontext
parameter to the context
given as the first argument.
_email_addresses
[ -c
] [ -n
plugin
]
Complete email addresses. Addresses are provided by plugins.
-
-c
Complete barelocalhost@domain.tld
addresses, without a name part or a comment. Without this option, RFC822 ‘Firstname Lastname
<``address``>
’ strings are completed. -
-n
plugin
Complete aliases fromplugin
.
The following plugins are available by default: _email-ldap
(see the
filter
style), _email-local
(completes user``@``hostname
Unix
addresses), _email-mail
(completes aliases from ~/.mailrc
),
_email-mush
, _email-mutt
, and _email-pine
.
Addresses from the _email-``foo
plugin are added under the tag
‘email-``foo
’.
Writing plugins
Plugins are written as separate functions with names starting with
‘_email-
’. They are invoked with the -c
option and compadd
options. They should either do their own completion or set the $reply
array to a list of ‘alias``:``address
’ elements and return 300
. New
plugins will be picked up and run automatically.
_files
The function _files
is a wrapper around _path_files
. It supports all
of the same functionality, with some enhancements — notably, it respects
the list-dirs-first
style, and it allows users to override the
behaviour of the -g
and -/
options with the file-patterns
style.
_files
should therefore be preferred over _path_files
in most cases.
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 command understands the
option ‘-``-help
’.
_guard
[ options
] pattern descr
This function displays descr
if pattern
matches the string to be
completed. It is intended to be used in the action
for the
specifications passed to _arguments
and similar functions.
The return status is zero if the message was displayed and the word to complete is not empty, and 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<TAB>
’. If the ‘-n
’ is already
followed by one or more digits (the pattern passed to _guard
) only the
message will be displayed; if the ‘-n
’ is followed by another
character, only options are completed.
_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 useful when the descr
comes from a pre-processed argument list which already contains an
expanded description. Note that this option does not disable the
‘%
’-sequence parsing done by compadd
.
The -12VJ
options and the group
are passed to compadd
and hence
determine the group the message string is added to.
The second -e
form gives a description for completions with the tag
tag
to be shown even if there are no matches for that tag. This form
is called by _arguments
in the event that there is no action for an
option specification. 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. Note that if there are no matches at
the time this function is called, compstate[insert]
is cleared, so
additional matches generated later are not inserted on the command line.
_multi_parts
[ -i
] 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.
_next_label
[ -x
] [ -12VJ
] tag
name
descr
[ option
... ]
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 description given in the tag-order
style
is preferred to the descr
passed to _next_label
.
The option
s 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
[ -P
| -p
precommand
]
This is the standard function called to handle completion outside any
special -``context``-
. It is called both to complete 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 completion 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 precommand
specifiers such as nohup
, removes the first word from the words
array, decrements the CURRENT
parameter, then calls ‘_normal -p $service
’. The effect is that ‘nohup
cmd ...
’ is treated in the
same way as ‘cmd ...
’.
-
-P
Reset the list of precommands. This option should be used if completing a command line which allows internal commands (e.g. builtins and functions) regardless of prior precommands (e.g. ‘zsh -c
’). -
-p
precommand
Appendprecommand
to the list of precommands. This option should be used in nearly all cases in which-P
is not applicable.
If the command name matches one of the patterns given by one of the
options -p
or -P
to compdef
, the corresponding completion 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 properly. 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
generally 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 thepattern
should be completed. -
-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 thecompadd
builtin. It gives direct control over which filenames should be ignored. If the option is not present, theignored-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.
_pick_variant
[ -b
builtin-label
] [ -c
command
] [
-r
name
]
``label``=``pattern
... label
[ arg
... ]
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
arg
...’ 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 ‘-b
builtin-label
’ is given, the command is tested to see if
it is provided as a shell builtin, possibly autoloaded; if so, the label
builtin-label
is selected as the label for the variant.
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
s, 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 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 specifications 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 completions are to be generated). The
completion target is restricted to the remaining word and any action
s
for the corresponding patterns are executed. In this case, nothing is
stripped from the command line string. The order of evaluation of the
action
s 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 succeeded. Thepattern
string ‘[]
’ is guaranteed never to match. Thelookahead
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 command line, the string containing theaction
is used to generate matches to insert at that point. -
/``pattern``/+
[%``lookahead``%
] [-``guard
] [:``tag``:``descr``:``action
]
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 theaction
s of the current and previously matched patterns are ignored even if the following ‘pattern
’ matches the empty string. -
(
spec
)
Parentheses may be used to groupsspec
s; note each parenthesis is a single argument to_regex_arguments
. -
spec
#
This allows any number of repetitions ofspec
. -
spec
spec
The twospec
s are to be matched one after the other as described above. -
spec
|
spec
Either of the twospec
s 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'/ \( \
/$'aaa\0'/ :'compadd aaa' \
/$'bbb\0'/ :'compadd bbb' \) \#
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
_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 following the
one being completed are themselves to be completed. 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 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 previous call to _regex_words
.
_requested
[ -x
] [ -12VJ
] tag
[ name
descr
[
command
[ arg
... ] ]
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
fi
... # 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 _description
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
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
complete 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.
_sequence
[ -s
sep
] [ -n
max
] [ -d
] function
[
-
] ...
This function is a wrapper to other functions for completing items in a
separated list. The same function is used to complete each item in the
list. The separator is specified with the -s
option. If -s
is
omitted it will use ‘,
’. Duplicate values are not matched unless -d
is specified. If there is a fixed or maximum number of items in the
list, this can be specified with the -n
option.
Common compadd
options are passed on to the function. It is possible
to use compadd
directly with _sequence
, though _values
may be more
appropriate in this situation.
_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
param
...
This function, together with _retrieve_cache
and _cache_invalid
,
implements a caching layer which can be used in any completion function.
Data obtained by costly operations 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
param
s 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 parameters. 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 example of the usage of the caching layer.
_tags
[ [ -C
name
] tag
... ]
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).
_tilde_files
Like _files
, but resolve leading tildes according to the rules of
filename expansion, so the suggested completions don’t start with a
‘~
’ even if the filename on the command-line does.
_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.
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 automatically 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 determine 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, desc
, 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 supported.
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 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 context 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
associative array used
by _arguments
. Hence the function calling _values
should declare the
local parameters state
, state_descr
, line
, context
and
val_args
:
local context state state_descr 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 that for _values
, the state
and
state_descr
are scalars rather than arrays. Only a single matching
state is returned.
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 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 _arguments
. 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
[ arg
...]
In many contexts, completion can only generate one particular 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 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
.
_widgets
[ -g
pattern
]
This function completes names of zle widgets (see
Widgets). The pattern
, if present,
is matched against values of the $widgets
special parameter,
documented in The zsh/zleparameter
Module.
20.7 Completion System Variables
There are some standard variables, initialised by the _main_complete
function and then used from other functions.
The standard variables are:
-
_comp_caller_options
The completion system usessetopt
to set a number of options. This allows functions to be written without concern for compatibility with every possible combination of user options. However, sometimes completion needs to know what the user’s option preferences are. These are saved in the_comp_caller_options
associative array. Option names, spelled in lowercase without underscores, are mapped to one or other of the strings ‘on
’ and ‘off
’. -
_comp_priv_prefix
Completion functions such as_sudo
can set the_comp_priv_prefix
array to a command prefix that may then be used by_call_program
to match the privileges when calling programs to generate matches.
Two more features are offered by the _main_complete
function. 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.
20.8 Completion Directories
In the source distribution, the files are contained in various
subdirectories of the Completion
directory. They may have been
installed in the same structure, or into one single 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 theUnix
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 themount
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 hierarchically, so, for example, both theLinux
andDebian
directories, as well as theX
directory, may be useful on your system.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.