ZSHCOMPSYS(1)ZSHCOMPSYS(1)NAMEzshcompsys - zsh completion system
DESCRIPTION
This describes the shell code for the new completion system. It con‐
sists of various shell functions; those beginning `comp' are to be
called directly by the user, while those beginning `_' are called by
the completion code. The shell functions of the second set which
implement completion behaviour and which may be bound to keystrokes,
are referred to as `widgets'.
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 that is
not writable it will save it in another file and tell you that file's
location. Note that it is up to you to make sure that the lines added
to .zshrc are actually run; you may, for example, need to move them to
an earlier place in the file if .zshrc usually returns early. So long
as you keep them all together (including the comment lines at the start
and finish), you can rerun compinstall and it will correctly locate and
modify these lines. Note, however, that any code you add to this sec‐
tion 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 imme‐
diately. 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 men‐
tioned 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 instal‐
lation any time you are being prompted for information, and your .zshrc
will not be altered at all; changes only take place right at the end,
where you are specifically asked for confirmation.
Use of compinit
This section describes the use of compinit to initialize completion for
the current session when run directly by the user; if you have run
compinstall it will be called automatically from your .zshrc.
To initialize the system, the function compinit should be in a direc‐
tory mentioned in the $fpath variable, 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-bind
all keys 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
to make sure that that widget is also re-bound.
Should you need to use the original completion commands, you can still
bind keys to the old functions by putting a `.' in front of the command
name, e.g. `.expand-or-complete'.
To speed up the running of compinit, it can be made to produce a dumped
configuration which will be read in on future invocations; this is the
default, although it 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'. On the next call to
compinit, it 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 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.
Autoloaded files
The convention for autoloaded functions used in completion is that they
start with an underscore; as already mentioned, the fpath/FPATH parame‐
ter must contain the directory in which they are stored. If zsh was
properly installed on your system, then fpath/FPATH automatically con‐
tains 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. Furthermore, if the directory in question ends in the path seg‐
ment Core, or has a subdirectory named Core, compinit will add all sub‐
directories of the directory where Core is to the path: this allows the
functions to be in the same format as in the zsh source distribution.
When compinit is run, it searches all such files accessible via
fpath/FPATH and reads the first line of each of them. This line should
contain one of the tags described below. Files whose first line does
not start with one of these tags are not considered to be part of the
completion system and will not be treated specially.
The tags are:
#compdef names...
The file will be made autoloadable and the function defined in
it will be called when completing names, each of which is either
the name of a command whose arguments are to be completed or one
of a number of special contexts in the form -context- described
below for the _complete function.
#compdef -p pattern
The file will be made autoloadable and the function defined in
it will be called when completing for a command whose name
matches the given pattern (a standard globbing pattern). Note
that only one pattern may be given.
#compdef -P pattern
Like the previous one, but the function will be called only if
no completion function for the command on the line could be
found.
#compdef -k style key-sequences...
This can be used to bind special completion functions to the
key-sequences specified. It creates a widget behaving like the
builtin widget style, which must be one of those that perform
completion, namely complete-word, delete-char-or-list,
expand-or-complete, expand-or-complete-prefix, list-choices,
menu-complete, menu-expand-or-complete, or reverse-menu-com‐
plete. If the zsh/complist module is loaded (see zshmod‐
ules(1)), the same happens to the menu-select widget.
The widget is then bound to all the key-sequences given, if any:
when one of the key-sequences is typed, the function in the file
will be invoked to generate the matches. Note that a key will
not be re-bound if if it already was (that is, was bound to
something other than undefined-key). The widget created has the
same name as the file and can be bound to any other keys using
bindkey as usual.
#compdef -K widget-name style key-sequences ...
This is similar to -k, with the same style and key-sequences
arguments, preceeded by a string giving the name of a widget.
In this case only one key-sequences argument may be given, but
the entire set of three arguments may be repeated with a differ‐
ent set of arguments. In particular, the widget-name must be
distinct in each set. It should begin with `_', else one will
be added, and 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 ]
This is used for files defining utility functions that are not
to be called directly as completion functions but should be
loaded automatically when invoked. Typically they are to be
called from within one of the completion functions.
The options will be given to the autoload builtin command when
making the function autoloaded. Most often, this will be +X to
force the function to be loaded immediately. Note that the -U
flag is always implicitly added.
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.
Note also that the functions for the completion system assume that the
KSH_AUTOLOAD option is not set and cannot be loaded when it is set. To
avoid having to unset KSH_AUTOLOAD, you can instead use one or more zwc
file(s) which have been created with the command zcompile -z to load
the functions for the completion system; see zshbuiltins(1). This
forces the functions to be autoloaded the way zsh normally loads func‐
tions.
Functions
The compinit file defines the following function, which may also be
called directly by the user.
compdef [ -an ] function names...
compdef -d names...
compdef -p [ -a ] function pattern
compdef -P [ -a ] function pattern
compdef -k [ -an ] function style key-sequences...
compdef -K [ -an ] function name style key-sequences ...
The first form tells the completion system to call the given
function when completing for the contexts or commands whose
names are given: this is like the #compdef tag. If the -n
option is given, any existing completion behaviour for particu‐
lar contexts or commands will not be altered. These definitions
can be deleted by giving the -d option as in the second form.
The form with -p is similar to the first, but function will be
called for all commands whose name matches the pattern; this is
like the #compdef -p function tag.
The form with -P is like the third, but the function will be
called only if no function for the command itself was found or
if one was found and it set the _compskip parameter to a value
not containing the substring patterns.
The form with -k defines a widget with the same name as the
function which will be called for each of the key-sequences;
this is like the #compdef -k tag. The function should generate
the completions needed and will otherwise behave like the
builtin widget whose name is given as the style argument. The
widgets usable for this are: complete-word, delete-char-or-list,
expand-or-complete, expand-or-complete-prefix, list-choices,
menu-complete, menu-expand-or-complete, and reverse-menu-com‐
plete, as well as menu-select if the zsh/complist module is
loaded. The option -n prevents the key being bound if it is
already to bound to something other than undefined-key.
The form with -K is similar and defines multiple widgets based
on the same function, each of which requires the set of three
arguments name, style and key-sequences, where the latter two
are as for -k and the first must be a unique widget name begin‐
ning with an underscore.
In each of the forms supporting it the -a option makes the func‐
tion autoloadable (exactly equivalent to autoload -U function).
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.
Overview
When completion is attempted somewhere on a command line the completion
system first tries to find out the context where completion was tried.
The context depends on such things as the name of the command when com‐
pleting an argument, and possibily also the name of an option when com‐
pleting an argument to that option.
The `context' of a completion is a string consisting of multiple
fields. This is used to look up styles that can be used to configure
the completion system. Since it is not possible to build the whole
context string in advance, completion functions may modify some of the
fields and hence the context used for lookup may vary during the same
call to the completion system.
The context string always consists of the following fields, separated
by colons and with a leading colon before the first:
· The literal string completion, saying that this style is used by
the completion system.
· The function; in many cases this field will be blank, but when
the completion system is called from other functions, like pre‐
dict-on or one of the functions in the Command directory of the
distribution, this field contains the name of that function,
often in an abbreviated form.
· The completer currently active, which is the name of the func‐
tion without the leading underscore. A `completer' is in over‐
all control of how completion is to be performed; `complete' is
the basic one for ordinary completion, but completers may per‐
form various related tasks such as correction, or modify the be‐
haviour of a later completer (see the section `Control Func‐
tions' below for more information).
· The context or command. This is either one of the special con‐
text names such as -condition- as explained for the _complete
completer below, or the name of the command we are completing
arguments for. 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 (e.g.
the completion function for the cvs command sets this field to
strings such as cvs-add when completing for the add sub-com‐
mand).
· The argument, describing which argument we are completing. Nor‐
mally this is either a string of the form argument-n, where n is
the number of the argument or it is a string of the form
option-opt-n when completing the n'th argument of the option
opt.
· The tag. Tags are used to discriminate between the types of
matches a completion function can generate in a certain context.
As an example, the context name
:completion::complete:dvips:option-o-1:files
says that normal completion was attempted on an argument of the dvips
command (more precisely: completion was attempted on the first argument
after the -o option) and the completion function will generate file‐
names for this context.
In many of the possible contexts the completion system can generate
matches, often multiple types of matches. These types are represented
as simple names called `tags'. The completion system will decide
internally what sort of tags are allowed; a list of the standard possi‐
bilities is given below. To determine in which order the tags are to
be used by the completion function, the `tag-order' style for the
appropriate context may be set, as described in the list of standard
styles below. Only those types of matches whose tags were selected by
this style will be produced, and in the order given, although the
default is to try all relevant tags in an order determined by the par‐
ticular completion in use.
The _complete_help bindable command described in the section `Bindable
Commands' below can be invoked to find out the context and tag names
and styles used at a particular point in completion. It shows the list
of contexts and tags that would be used in if completion were tried at
the current cursor position. Hence one can easily find out all the
information needed to change the behaviour of the tag-order style for a
particular context.
Completion behaviour can be modified by various other styles defined
with the zstyle builtin command (see zshmodules(1)). When looking up
styles the completion system uses full context names, including the
tag.
Styles determine such things as how the matches are generated; some of
them correspond to shell options (for example, the use of menu comple‐
tion), but styles provide more specific control. They can have any
number of strings as their value. Looking up the value of a style
therefore consists of two things: the context, which may be matched as
a pattern, and the name of the style itself, which must be given
exactly.
For example, many completion functions can generate matches in a simple
and a verbose form and use the verbose style to decide which form
should be used. To make all such functions use the verbose form, put
zstyle ':completion:*' verbose yes
in one of the startup files like .zshrc; this sort of style can also be
configured with the compinstall function. This definition simply means
that the verbose style has yes as its value in every context inside the
completion system. If the context pattern were `*', the verbose style
would have this value anywhere the style mechanism is used, not just in
completion.
As a more specific example, the completion function for the kill
builtin command uses the verbose style to decide if jobs and processes
are listed only as job numbers and process identifiers or if they are
listed with the full job texts and the command lines of the processes
(the latter is achieved by calling the ps command). To make this
builtin list the matches only as numbers one could call:
zstyle ':completion:*:*:kill:*' verbose no
Furthermore, if one wanted to see the command lines for processes but
not the job texts one could use the fact that the context name contains
the tag name when styles are looked up. As the function for the kill
builtin command uses the tags jobs and processes, we can use:
zstyle ':completion:*:*:kill:*:jobs' verbose no
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 pre‐
ferred over patterns (for example, `:completion::complete:foo' is more
specific than `:completion::complete:*'), and longer patterns are pre‐
ferred over shorter patterns.
As with tags, completion functions can use any style they choose, so
there can't be a complete list. However, the following two sections
list those tags and styles that are used in many places of the comple‐
tion system.
Standard Tags
Here are the tags currently used by the completion system. Some of
them are only used when looking up styles and do not refer to a partic‐
ular type of match.
accounts
used to look up the users-hosts style
all-files
for the names of all files (as distinct from a particular sub‐
set, see the globbed-files tag).
all-expansions
used by the _expand completer when adding the single string con‐
taining all possible expansions
arguments
when an argument of a command may be completed
arrays for names of array parameters
association-keys
for keys of associative arrays; used when completing inside a
subscript of 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
used for commands like stty when completing characters; also
used when completing character classes after a opening bracket
colors for color names
commands
for names of external commands and names of sub-commands (used
by some commands like cvs)
corrections
used by the _approximate and _correct completers for the possi‐
ble corrections
cursors
for cursor names used by X programs
default
used to look up default values for various styles that may also
be set for tags that are used when generating matches; note that
this tag is used when only the function field of the context
name is set up
descriptions
used when looking up the value of the format style for descrip‐
tions
devices
for names of device special files
directories
for names of directories
directory-stack
for entries in the directory stack
displays
for X display names
domains
for network domains
expansions
used by the _expand completer for individual possibilities
resulting from expansion of a word
extensions
for X server extensions
files the generic file-matching tag used by completion functions that
can complete the names of some kind of file
fonts used for X font names
functions
names of functions, normally shell functions although certain
commands may understand other kinds of function
globbed-files
for names of files matching the glob pattern used by completion
functions that expect a certain type of file
groups used when completing names of user groups
history-words
for words from the history
hosts for hostnames
indexes
used for array indexes
jobs used for jobs
keymaps
for names of zsh keymaps
keysyms
for names of X keysyms
local-directories
for names of directories which are subdirectories of the current
working directory when completing for the cd and related builtin
commands
libraries
for names of system libraries
limits for system limits
manuals
for names of manual pages
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
nicknames
for nicknames of NIS maps
options
for command options
original
used by the _approximate, _correct and _expand completers when
adding the original string
other-accounts
used to look up the users-hosts style
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 for the cd and related builtin commands
paths used to look up the values of the expand, ambiguous and spe‐
cial-dirs styles
pods for perl pods (documentation files)
ports for communication ports
prefixes
for prefixes (like those of an URL)
printers
for printer names
processes
for process identifiers
processes-list
used to look up the command style when generating the list to
display 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)
tags for tags (e.g. rpm tags)
targets
for makefile targets
types for types of whatever (e.g. address types for the xhost command)
urls used to look up the path and local styles when completing URLs
users for usernames
values when completing a value out of a set of values (or a list of
such values)
version
used by _call to look up the command to run to determine the
installed version of various other commands (such as diff and
make).
warnings
used to look up the format style for warnings
widgets
for zsh widget names
windows
for IDs of X windows
zsh-options
for shell options
Standard Styles
Here are the names of the styles used by the completion system. Note
that the values of several of these styles represent boolean values;
here, any of the strings `true', `on', `yes', and `1' can be used for
the truth value `true' and the strings `false', `off', `no', and `0'
are interpreted as `false'. The behavior for any other value is unde‐
fined unless the description for the particular style mentions other
possible values; in particular, the default value may be either on or
off if the style is not set.
Some of these styles are tested for every tag used to add possible
matches and for the default tag (most notably menu, list-colors and the
styles controlling the completion listing like list-packed and
last-prompt). When tested for the default tag, only the function field
of the context will be set up, so the default value will normally be
set like:
zstyle ':completion:*:default' menu ...
accept-exact
This is tested for the default tag and the tags used when gener‐
ating matches. If it is set to `true' for at least one match
which is the same as the string on the line, this match will
immediately be accepted.
add-space
This style is used by the _expand completer. If it is `true'
(the default), a space will be inserted after all words result‐
ing from the expansion (except for directory names which get a
slash).
It is also used by the _prefix completer to decide if a space
should be inserted before the suffix.
ambiguous
This applies when completing non-final components of filename
paths. If it is set, the cursor is left after the first ambigu‐
ous component, even if menu completion is in use. It is tested
with the paths tag.
assign-list
When completing after an equal sign, the completion system nor‐
mally completes only one filename. In some cases, particularly
for certain parameters such as PATH, a list of filenames sepa‐
rated by colons is required. 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 which 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. Depend‐
ing 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.
break-keys
This style is used by the incremental-complete-word widget
(found in the Functions/Zle directory of the distribution). Its
value should be a pattern and all keys matching this pattern
will cause the widget to stop incremental completion without the
key having any further effect.
command
In many places, completion functions need to call external com‐
mands to generate the list of completions. This style can be
used to override the command which is called in some such cases.
The elements of the value are joined with spaces to form a com‐
mand 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 function generating process IDs as matches
uses this style with the processes tag to generate the IDs to
complete and when the verbose style is `true', it uses this
style with the processes-list tag to generate the strings to
display. When using different values for these two tags one
should ensure that the process IDs appear in the same order in
both lists.
completer
The strings given as the value of this style provide the names
of the completer functions to use. The available completer func‐
tions are described in the section `Control Functions' below.
Each string may be 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
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 makes only 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.
Note that the widget functions from the distribution that call
the completion code (namely, the incremental-complete-word and
the predict-on widgets) set up their top-level context name
before calling completion. This allows one to define different
sets of completer functions for normal completion and for these
widgets. For example, to use completion, approximation and cor‐
rection for normal completion, completion and correction for
incremental completion and only completion for prediction one
could use:
zstyle ':completion:*' completer _complete _correct _approximate
zstyle ':completion:incremental:*' completer _complete _correct
zstyle ':completion:predict:*' completer _complete
The default value for this style is _complete _ignored, i.e.
normally only completion will be done, first using the
ignored-patterns style and the $fignore array and then without
ignoring matches.
completions
This style is used by the _expand completer function.
If this is set to an non-empty string it should be an expression
usable inside a `$((...))' arithmetical expression. The com‐
pleter function evaluates this expression and if the result is
`1', no expansions will be generated, but instead the comple‐
tions will be generated as normal and all of them will be
inserted into the command line.
condition
This style is used by the _list completer function.
If it is not set or set to the empty string, the insertion of
matches will be delayed unconditionally. If it is set, the
value should be an expression usable inside a `$((...))' arith‐
metical expression. In this case, delaying will be done if the
expression evaluates to `1'. For example, with
zstyle ':completion:*:list:::' condition '${NUMERIC:-1} != 1'
delaying will be done only if given an explicit numeric argument
other than `1'.
cursor The predict-on widget uses this style to decide where to place
the cursor after completion has been tried. Values are:
complete
The cursor is left where it was when completion finished,
but only if it is after a character equal to the one just
inserted by the user. If it is after another character,
this value is the same as `key'.
key The cursor is left after the nth occurrence of the char‐
acter just inserted, where n is the number of times that
character appeared in the word before completion was
attempted. In short, this has the effect of leaving the
cursor after the character just typed even if the comple‐
tion code found out that no other characters need to be
inserted at that position.
Any other value for this style unconditionally leaves the cursor
at the position where the completion code left it.
disable-stat
This is used with an empty tag by the function completing for
the cvs command to decide if the zsh/stat module should be used
to generate names of modified files in the appropriate places
(this is its only use). If set, completion will use the ls com‐
mand.
domains
If set, gives the names of network domains that should be com‐
pleted. If this is not set by the user domain names will be
taken from the file /etc/resolv.conf.
expand This style is used when completing strings consisting of multi‐
ple parts, such as path names. If its value contains 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 it contains the string `suffix' and normal
(non-menu-) completion is used, matching names for components
after the first ambiguous one will also be added. This means
that the resulting string is the longest unambiguous string pos‐
sible, but if menu completion is started on the list of matches
generated this way (e.g. due to the option AUTO_MENU being set),
this will also cycle through the names of the files in pathname
components after the first ambiguous one.
file-patterns
In most places where filenames are completed, the function
_files is used which can be configured with this style. If the
style is unset, _files offers, one after another, up to three
tags: `globbed-files', `directories' and `all-files', depending
on the types of files expected by the caller of _files.
If the file-patterns style is set, the default tags are not
used. Instead, the value of the style says which tags and which
patterns are to be offered. The strings in the value contain
specifications of the form `pattern:tag'; each string may con‐
tain any number of such specifications. The pattern gives a
glob pattern that is to be used to generate filenames. If it
contains the sequence `%p', that is replaced by the pattern(s)
given by the calling function. Colons in the pattern must be
preceded by a backslash to make them distinguishable from the
colon before the tag. If more than one pattern is needed, the
patterns can be given inside braces, separated by commas. The
tags of all strings in the value will be offered by _files
(again, one after another) and used when looking up other
styles. For strings containing more than one specification, the
filenames for all specifications will be generated at the same
try. 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. If that is given, this description 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 the names of all files if no object file
matches the string on the line, one would do:
zstyle ':completion:*:*:rm:*' file-patterns \
'*.o:object-files' '%p:all-files'
Another interesting example is to change the default behaviour
that makes completion first offer files matching the patterns
given by the calling function, then directories and then all
files. Many people prefer to get both the files matching the
given patterns and the directories in the first try and all
files at the second try. To achieve this, one could do:
zstyle ':completion:*' file-patterns \
'%p:globbed-files *(-/):directories' '*:all-files'
Note also that 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 completion function that generates filenames as possible
matches uses this style with the files tag to determine in which
order the names should be listed and completed when using menu
completion. The value may be one of `size' to sort them by the
size of the file, `links' to sort them by the number of links to
the file, `modification' (or `time' or `date') to sort them by
the last modification time, `access' to sort them by the last
access time, or `inode' (or `change') to sort them 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 decreas‐
ing order.
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 which is immediately 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 and all tags used when
generating matches. This allows one to turn unconditional list‐
ing on for certain types of matches.
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 sequences to specify output attributes, such as
`%B', `%S' and `%{...%}'.
For the same purpose, this style is also tested with the tags
used when matches are generated before it is tested for the
descriptions tag. This gives the possibility to define differ‐
ent format strings for different types of matches.
Note also that some completer functions define additional
`%'-sequences. These are described for the completer functions
that make use of them.
For the messages tag, this defines a string used by some comple‐
tion functions to display messages. Here, the `%d' is replaced
with the message given by the completion function.
Finally, when set with the warnings tag, the format string is
printed when no matches could be generated at all. In this case
the `%d' is replaced with the descriptions for the matches that
were expected. If the value does not contain a `%d', then those
descriptions are added in the same way as matches are added,
i.e. they appear below the value for the format style laid out
in columns. The descriptions are added as if for the tag warn‐
ings so that you can use the list-colors style for that tag to
highlight them.
The `%' for the sequences that are replaced by strings provided
by the completion functions like the `%d' may be followed by
field width specifications as described for the zformat builtin
command from the zutil module, see zshmodules(1).
glob Like completions, this is used by the _expand completer.
The value is used like the one for completions and if it evalu‐
ates to `1', globbing will be attempted on the words resulting
from substitution (see the substitute style) or the original
string from the line.
group-name
The completion system can put different types of matches in dif‐
ferent groups which are then displayed separately in the list of
possible completions. This style can be used to give the names
for these 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 parame‐
ters and reserved words as possible completions. To have the
external commands and shell functions listed separately, one can
set:
zstyle ':completion:*:*:-command-:*:commands' group-name commands
zstyle ':completion:*:*:-command-:*:functions' group-name functions
This also means that if the same name is used for different
types of matches, then those matches will be displayed together
in the same group.
If the name given is the empty string, then 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 to be used together with the group-name style.
Once different types of matches are put into different groups,
this style can be used to define in which order these groups
should appear when listing (compare tag-order, which determines
which completions appear at all). The strings in the value are
taken as group names and the named groups will be shown in the
order in which their names appear in the value. All groups
whose names are not given in the value of this style will appear
in the order defined by the function generating the matches.
For example, to have names of builtin commands, shell functions
and external commands appear in this order when completing in
command position one would set:
zstyle ':completion:*:*:-command-:*' group-order \
builtins functions commands
groups A style holding the names of the groups that should be com‐
pleted. If this is not set by the user, the group names from the
YP database or the file `/etc/group' will be used.
hidden If this is set to one of the `true' values, the matches for the
tags for which this is set will not appear in the list; only the
description for the matches as set with the format style will be
shown. If this 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 possi‐
ble completions at all, the tag-order style can be modified as
described below.
hosts A style holding the names of hosts that should be completed. If
this is not set by the user the hostnames in `/etc/hosts' will
be used.
hosts-ports
This style is used by commands that need or accept hostnames and
ports. The strings in the value should be of the form
`host:port'. These hostnames and ports are completed depending
on the information already on the line, so that if, for example,
the hostname is already typed, only those ports specified for
that host will be completed. Multiple ports for the same host
may appear.
ignore-line
This style is tested for the tags used when generating matches.
If it is set to `true', then none of the words that are already
on the line will be considered possible completions.
Note that you almost certainly don't want to set this for a gen‐
eral 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 for the files tag to determine whether to
ignore the names of directories already mentioned in the current
word, or the name of the current working directory. The value
must include one or both of the following strings:
parent The name of any directory whose path is already contained
in the word on the line is ignored. For example, when
completing after foo/../, the directory foo will not be
considered a valid completion.
pwd The name of the current working directory will not be
completed, so that, 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 only when names of directories are completed, not
when completing names of files.
Note that names of directories ignored because of one of the
tests will be ignored in the same way as the matches ignored
because of the ignored-patterns style. I.e., by using the
_ignored completer it is possible to complete these directories
nonetheless.
ignored-patterns
This style can be used to specify a list of patterns which are
tested against against the trial completions in a given context;
any matching completions will be removed from the list of possi‐
bilities. The _ignored completer can appear in the list of com‐
pleters to produce a list which includes these matches once
more. This is a more configurable version of the shell parame‐
ter $fignore.
Note that during the execution of completion functions, the
EXTENDED_GLOB option is in effect, so the characters `#', `~'
and `^' have special meanings in the patterns.
insert-ids
When completing process IDs, for example as arguments to the
kill and wait builtins, completion allows the user to type the
name of a command, which will be converted to the appropriate
process ID. A problem arises when the process name typed is not
unique. By default (or if this style is set explicitly to
`menu') the name will be converted immediately to a set of pos‐
sible IDs, and menu completion will be started to cycle through
them. If the value of the style is `single', however, the shell
will wait until the user has typed enough to make the command
unique before converting the name to an ID; the user must type
any additional characters required. 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 of the corresponding
IDs.
insert-tab
If this has one of the `true' values, the completion system will
insert a TAB character (assuming it was used to start comple‐
tion) instead of performing completion when there is no
non-blank character to the left of the cursor. If set to
`false', completion will be done even there.
The default value of this style is `true' unless when completing
inside the vared builtin command, where it defaults to `false'.
insert-unambiguous
This is used by the _match and _approximate completer functions,
where the possible completions may not have a common prefix so
that menu completion is often the most useful may of choosing
completions. If the style is set to `true', the completer will
start menu completion only if no unambiguous string could be
generated that is at least as long as the original string typed
by the user. Note that the _approximate completer uses it after
setting the completer field in the context name to one of cor‐
rect-num or approximate-num, where num is the number of errors
that were accepted.
last-prompt
This is used to determine if the completion code should try to
put the cursor back onto the previous command line after showing
a completion listing (as for the ALWAYS_LAST_PROMPT option). As
with several other styles, it is tested for the default tag as
well as all the possible tags when generating matches. The cur‐
sor will be moved back to the previous line if this style is
`true' for all types of matches added. Note also that this is
independent of the numeric argument, unlike the
ALWAYS_LAST_PROMPT option.
list This style is used by the _history_complete_word bindable com‐
mand (using the context prefix `:completion:history-words') and
by the incremental-complete-word widget (using the context pre‐
fix `:completion:incremental).
The _history_complete_word bindable command uses this style to
decide if the available matches should be shown.
When using the incremental-complete-word widget, this style says
if the matches should be listed on every key press (if they fit
on the screen).
The predict-on widget uses this style to decide if the comple‐
tion should be shown even if there is only one possible comple‐
tion. This is done if the value of this style is the string
always.
list-colors
If the zsh/complist module is used, this style can be used to
set color specifications as with the ZLS_COLORS and ZLS_COLOURS
parameters (see the section `The zsh/complist Module' in zshmod‐
ules(1)).
If this style is set for the default tag, the strings in the
value are taken as specifications that are to be used every‐
where. 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, the group-name style must be set to an empty string. If
the group-name tag specifies other names for the groups the
matches in these groups can be colored by using these names
together with the `(group)...' syntax described for the
ZLS_COLORS and ZLS_COLOURS parameters and adding the specifica‐
tions to the value for this style with the default tag.
It is possible to use the same specifications 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-packed
Like the list-colors style, this is tested with the default tag
and all tags used when generating matches. If it is set to
`true' for a tag, the matches added for it will be listed as if
the LIST_PACKED option were set. If it is set to `false', they
are listed normally.
list-prompt
If this style is set for the default tag, completion lists that
don't fit on the screen can be scrolled (see the description of
the zsh/complist module in zshmodules(1)). The value, if not
the empty string, will be displayed after every screenful and
the shell will prompt for a key press; if the style is unset, 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', which will be replaced by the number of the last match
shown and the total number of matches; and `%p' and `%P', which
will be replaced by `Top' when at the beginning of the list,
`Bottom' when at the end and the position shown in percent of
the total length otherwise. In each of these cases the form
with the uppercase letter is replaced by a string of fixed
width, padded to the right with spaces. As in other prompt
strings, the escape sequences `%S', `%s', `%B', `%b', `%U',
`%u', and `%{...%}' for entering and leaving the display modes
standout, bold and underline are also available.
Note that this style has a default value. If you don't want to
use scrolling, set this style to an empty string.
list-rows-first
This style is tested in the same way as the list-packed style
and determines if matches are to be listed in a rows-first fash‐
ion, as for the LIST_ROWS_FIRST option.
local This style is used by completion functions which generate URLs
as possible matches to add suitable matches when a URL points to
a local web server, that is, one whose files are available
directly on the local 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, completion after
`http://toast/~yousir/' will attempt to match the name `toast'
against the first argument to the style, and if successful will
look in the directory under ~yousir given by the third argument
to the style for possible completions.
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 done with the `*' inserted.
matcher
This style is tested for tags used when generating matches. Its
value is used as an match specification additional to any given
by the matcher-list style which should be in the form described
in the section `Matching Control' in zshcompwid(1).
matcher-list
This style is used by the main completion function to retrieve
match specifications that are to be used everywhere. Its value
should be a list of such specifications. The completion system
will try them one after another for each completer selected. For
example, to first try simple completion and, if that generates
no matches, case-insensitive completion one would do:
zstyle ':completion:*' matcher-list '' 'm:{a-zA-Z}={A-Za-z}'
The style allows even finer control by specifying a particular
completer, without the leading underscore, in the third field of
the completion context. For example, if one uses the completers
_complete and _prefix but wants to try case-insensitive comple‐
tion only when using the _complete completer, one would do:
zstyle ':completion:*' completer _complete _prefix
zstyle ':completion:*:complete:*' matcher-list \
'' 'm:{a-zA-Z}={A-Za-z}'
Note that the completer style allows user-defined names to be
used in the context instead of the name of the completer. This
is useful if, for example, one wants to try normal completion
without a match specification and with case-insensitive matching
first, correction if that doesn't generate any matches and par‐
tial-word completion if that doesn't yield any matches either.
In this case one can give the _complete completer more than once
in the completer style and define different match specifications
for each occurrence, as in:
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; further, some completers such as _correct and _approxi‐
mate do not use the match specifications at all. However, it is
always safe to use the simple form for this style (as in the
first example above), since any completers which do not use
match specifications will only ever be called once, rather than
once per specification.
max-errors
This is used by the _approximate and _correct completer func‐
tions 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 wer 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'.
menu If this is set to true in a given context, using any of the tags
defined for a given completion, menu completion will be used.
The tag `default' can be used to set the default value, but a
specific tag will take precedence. If none of the values found
in this way is true but at least one is set to `auto' the behav‐
iour will be as for the AUTO_MENU option. Finally, if one of
the values is explicitly set to false, menu completion will be
turned off even if it would otherwise be active (for example,
with the MENU_COMPLETE option).
In addition to (or instead of) the above possibilities, the
value may contain the string `select', optionally followed by an
equal sign and a number. In this case menu-selection (as
defined by the zsh/complist module) will be started. Without
the optional number, it will be started unconditionally and with
a number it will be started only if at least that many matches
are generated; 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'. This will only start menu-selection if the wid‐
get invoked does completion, not simply listing as done by
delete-char-or-list; to start menu-selection even here, use the
value `select=long-list'.
numbers
This is used with the jobs tag. If it is `true', the shell will
complete the job numbers instead of the shortest unambiguous
strings of the jobs' command lines. 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 dif‐
fer 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 com‐
pletion list is generated; this is the default behaviour of
_oldlist. However, if there is an old list and this style con‐
tains 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 wid‐
get, 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 pro‐
duce 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-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 type 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 correc‐
tions, 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 one 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 these completers use this style
after setting the completer field in the context name to cor‐
rect-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 This is used together with the the urls tag by completion func‐
tions that generate URLs as possible matches. It should be set
to the path of a directory containing sub-directories named
after the retrieval methods which occur as the first part of a
URL, i.e. `http', `ftp', `bookmark', and so on. These
sub-directories should contain files and other sub-directories
whose pathnames are possible completions after the initial
`http://', `ftp://', etc. See the description in the file _urls
in the User sub-directory of the completion system for more
information.
The function that completes color names also uses this style
with the colors tag. Here, 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.
ports A style holding the service names of ports to complete. If this
is not set by the user, the service names from `/etc/services'
will be used.
prefix-hidden
This is used when matches with a common prefix are added (e.g.
option names). If it is `true', this prefix will not be shown
in the list of matches.
The default value for this style is `false'.
prefix-needed
This, too, is used for matches with a common prefix. If it is
set to `true' this common prefix has to be typed by the user to
generate the matches. E.g. for options this means that the `-',
`+', or `--' has to be on the line to make option names be com‐
pleted at all.
The default style for this style is `true'.
prompt The incremental-complete-word widget shows the value of this
style in the status line during incremental completion. The
string value may contain any of the following substrings in the
manner of the PS1 and other prompt parameters:
%c Replaced by the name of the completer function that gen‐
erated the matches (without the leading underscore).
%l When the list style is set, replaced by `...' if the list
of matches is too long to fit on the screen and with an
empty string otherwise. If the list style is `false' or
not set, `%l' is always removed.
%n Replaced by the number of matches generated.
%s Replaced by `-no match-', `-no prefix-', or an empty
string if there is no completion matching the word on the
line, if the matches have no common prefix different from
the word on the line, or if there is such a common pre‐
fix, respectively.
%u Replaced by the unambiguous part of all matches, if there
is any, and if it is different from the word on the line.
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 com‐
pletion list does not fit on the screen as a whole. The same
escapes as for the list-prompt style are understood, but give
the number of 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. Its value should be `0' (zero) to scroll by
half-screenfuls, a positive integer to scroll by that many lines
and a negative number to scroll by the number of lines of the
screen minus that number (or plus the number, since it is nega‐
tive). The default is to scroll by single lines.
single-ignored
This is used by the _ignored completer. It specifies what
should be done if it can generate only one match, which is often
a special case. 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 so that one can easily select
either of them.
sort If set to `true', completion functions that generate words from
the history as possible matches sort these words alphabetically
instead of keeping them in the order in which they appear in the
history (from youngest to oldest).
This is also used by the _expand completer. Here, 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 (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 comple‐
tions; if it is set to `..', only `..' will be added.
squeeze-slashes
If set to `true', sequences of slashes (as in `foo//bar') will
be treated as if they were only one slash when completing path‐
names. 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 always insert matches as if menu completion were started
and will stop when the last match is inserted. If this style is
set to `verbose' a message will be displayed when the last match
is reached.
stop-keys
This style is used by the incremental-complete-word widget. Its
value is treated similarly to the one for the break-keys style.
However, in this case all keys matching the pattern given as its
value will stop incremental completion and will then execute
their usual function.
subst-globs-only
This is used by the _expand completer. As for the glob style,
the value should be a value usable in a `$((...))' arithmetical
expression. If it evaluates to `1', 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.
substitute
This style controls whether the _expand completer will first try
to expand all substitutions in the string (such as `$(...)' and
`${...}'). It should be set to a number or an non-empty string
which is an expression usable inside a `$((...))' arithmetical
expression. Expansion of substitutions will be done if the
expression evaluates to `1'. For example, with
zstyle ':completion:*:expand:::' substitute '${NUMERIC:-1} != 1'
substitution will be performed only if given an explicit numeric
argument other than `1', as by typing `ESC 2 TAB'.
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-pat‐
terns style for an exception to this behavior.)
For example:
zstyle ':completion:*:complete:-command-:*' tag-order \
'commands functions'
specifies that completion in command position should offer only
completions for external commands and shell functions immedi‐
ately.
In addition to tag names, each string in the value may take one
of the following forms:
- If any string in the value consists of only a hyphen,
then only the tags specified by the other strings in the
value are generated. Normally all tags not explicitly
selected are tried last if the specified tags fail to
generate any matches. This means that a 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 ...
In strings not starting with an exclamation mark, it is
also possible to specify tag labels instead of only tags,
where tag is one of the tags offered by the completion
function for the current context and label is a name.
For this, the completion function will generate matches
in the same way as for the tag but it will use the label
in place of the tag in the context names used to look up
styles. If the label starts with a hyphen, the tag is
prepended to the label to form the name used for lookup.
This can be used to make the completion system try a cer‐
tain tag more than once, supplying different style set‐
tings for each attempt. For example,
zstyle ':completion:*:*:-command-:*' \
tag-order 'functions:-non-comp'
zstyle ':completion:*:functions-non-comp' \
ignored-patterns '_*'
This makes completion in command position first try only
names of shell functions that don't match the pattern
`_*'. If that generates no matches, the default of trying
all the other things that can be completed in command
position is used, including the names of all shell func‐
tions.
The label may optionally be followed by a second colon
and a description. This description will then be used
for the `%d' in the value of the format style instead of
the default description supplied by the completion func‐
tion. Spaces in the description have to be quoted by
preceding them with a backslash and a `%d' appearing in
the description is replaced with the description given by
the completion function.
func() The function func is called, which can then define the
order in which tags are to be used based on additional
context information. See the _sort_tags function below
for a description of how such functions can be imple‐
mented. The return value of the function is used to
decide if the following values for the style should be
used. If it is zero, they are used and if it is
non-zero, they are not used. For example:
non-empty() { [[ -n $PREFIX ]] }
zstyle ':completion:*:*:-command-:*' tag-order 'non-empty()'
Makes completion in command position happen only if the
string on the line is not empty. This is tested using
the PREFIX parameter which is special in completion wid‐
gets; see zshcompwid for a description of these special
parameters.
In each of the cases above, the tag may also be a pattern or more than
one pattern inside braces and separated by commas. In this case all of
the offered tags matching the pattern(s) will be used except for those
that are given explicitly in the same string. There are probably two
main uses of this. One is the case where one wants to try one of the
tags more than once, setting other styles differently for each try, but
still wants 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 under‐
score the first time completion is tried, one could do:
zstyle ':completion:*:*:-command-:*' tag-order \
'functions:-non-comp *' functions
zstyle ':completion:*:functions-non-comp' ignored-patterns '_*'
Here, the completion system will first try all tags offered, but will
use the tag label functions-non-comp when looking up styles for the
function names completed. For this, the ignored-patterns style is set
to exclude functions starting with an underscore from the set of possi‐
ble matches. If none of the generated matches match the string on the
line, the completion system will use the second value of the tag-order
style and complete functions names again, but this time using the name
functions to look up styles, so that the ignored-patterns style is not
used and all function names are considered.
Of course, this can also be used to split the matches for one tag 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, this makes options beginning with `--',
options beginning with a single `-' or `+' but containing multiple
characters, and single-letter options be displayed in separate groups
with different descriptions.
The second interesting use of patterns is the case where one wants to
try multiple match specifications one after another. The matcher-list
style offers something similar, but it is tested very early in the com‐
pletion 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.
If no style has been defined for a context, the strings `(|*-)argu‐
ment-* (|*-)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.
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 make the
definition for `compctl -T' be used, and the substring `default'
to make the one for `compctl -D' be used.
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, while completing arguments to the com‐
mand foo, if this was handled by a command function _foo, com‐
pctl would never be tried, while if it was handled by _default,
compctl would be tried.
users This may be set to a list of names that should be completed
whenever a username is needed. If it is not set or the string on
the line doesn't match any of the strings in this list, all
usernames will be completed.
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. For such commands, only the pairs from this
style are used and if, for example, the username is already
typed, then only the hostnames for which there is a pair with
that username is defined.
If set for the my-accounts tag, this is used for commands such
as rlogin and ssh; in this case the style should contain the
names of the user's own accounts on remote hosts. If set for
the other-accounts tag, it is used for commands such as talk and
finger and should contain other people's accounts. Finally, it
may also be used by some commands with the accounts tag.
users-hosts-ports
Like users-hosts but used for commands like telnet and contain‐
ing strings of the form `user@host:port'.
verbose
This is used in several contexts to decide if only a simple or a
verbose list of matches should be generated. For example some
commands show descriptions for option names if this style is
`true'.
The default value for this style is `true'.
word This is used by the _list completer, which prevents the inser‐
tion 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 per‐
formed on another word with the same contents, completion will
not be delayed.
CONTROL FUNCTIONS
The initialization script compinit redefines all the widgets which per‐
form completion to call the supplied widget function _main_complete.
This function acts as a wrapper calling the so-called `completer' func‐
tions that generate matches. If _main_complete is called with argu‐
ments, 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 com‐
pletion 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 value of the completer func‐
tions to decide if other completers should be called. If the return
value 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 argu‐
ments 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 anme and arguments to call to gener‐
ate the matches.
The following completer functions are contained in the distribution
(users may write their own):
_approximate
This completer function uses the _complete completer to generate
a list of strings for the context the cursor is currently in,
allowing you to specify a maximum number of errors: see the
description of approximate matching in zshexpn(1) for how errors
are counted. The resulting list of corrected and completed
strings is then presented to the user. The intended use of this
completer function is to try after the normal _complete com‐
pleter by setting:
zstyle ':completion:*' completer _complete _approximate
This will give correcting completion if and only if normal com‐
pletion yields no possible completions. When corrected comple‐
tions are found, the completer will normally start menu comple‐
tion allowing you to cycle through these strings.
This completer uses the tags corrections and original when gen‐
erating 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.
As with all completers, _approximate uses its name without the
underscore in the completer field of the context name. Once it
has started trying to generate matches, it will append a minus
sign and the number of errors accepted to its name. _approxi‐
mate will first look for completions with one error, then two,
and on so up to the limit on the number of errors set by the
max-errors style. Hence on the first try the completer field of
the context contains `approximate-1', on the second try `approx‐
imate-2', and so on.
When _approximate is called from another function, the number of
errors to accept may be given with the -a option. Its argument
should be the same as the value of the max-errors style, all in
one string.
_complete
This completer generates all possible completions in a con‐
text-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-, as mentioned above for the #compdef tag, are
handled specially. These are:
-array-value-
for completion on the right hand side of an array-assign‐
ment (`foo=(...)').
-brace-parameter-
for completing the name of a parameter expansion within
braces (`${...}').
-command-
for completing in a command position.
-condition-
for completion inside conditions (`[[...]]').
-default-
for generating completions when no special completion
function is used.
-equal-
for completion of words beginning with an equal sign
-first-
for adding completions before any other completion func‐
tions are tried; if this function sets the _compskip
parameter to all, no other completion functions will be
called, if it is set to a string containing the substring
patterns, no pattern completion functions will be called,
and if it is set to a string containing default the func‐
tion for the `-default-' context will not be called, but
functions defined for commands will.
-math- for completion inside mathematical contexts, such as
`((...))'.
-parameter-
for completing the name of a parameter expansion
(`$...').
-redirect-
for completion after a redirection operator.
-subscript-
for completion inside subscripts.
-tilde-
for completion after a tilde (`~') character, but before
a slash.
-value-
for completion on the right hand side of an assignment.
Default implementations are supplied for each of these contexts,
in most cases named after the context itself (e.g. completion
for the `-tilde-' context is done by the function named
`_tilde').
Before trying to find a function for a specific context, _com‐
plete checks if the parameter `compcontext' is set to a
non-empty value. If it is, 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 (com‐
mands and their arguments) and is not used by the completion
system itself, but has a function handling completion for it.
_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, hence
this is similar to spell-checking. It calls _approximate but
uses a different completer field in the context name.
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 com‐
pletion 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
should be the same as the value of 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 gener‐
ated by the _correct completer -- and probably more.
_expand
This completer function does not really do 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. When using this, one should not use the
expand-or-complete widget, but instead use complete-word, as
expand-or-complete will expand the string on the line before the
completion widget is called. 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. In which order
these strings are generated and which of these strings are gen‐
erated at all can be controlled by using the group-order style
and by modifying the tag-order style, as usual.
The format string for all-expansions and for expansions may con‐
tain the sequence `%o' which will be replaced by the original
string from the line.
Which kind of expansion is tried is controlled by the substi‐
tute, glob and subts-globs-only styles. Note that none of these
has a default value so that they have to be set to make _expand
generate any expansions at all.
There is another style, completions, which allows _expand to
display or insert all completions generated for the string. The
use of this is that the tags expansions and all-expansions are
available, unlike with _complete.
When _expand is called as a function, the different modes may be
selected with options. The -c corresponds to the completions
style, -s to substitute, -g to glob and -o to subst-globs-only.
_history
Complete words from the shell's command history. This com‐
pleter uses the remove-all-dups, and sort styles also used by
the _history_complete_word bindable command, see the section
`Bindable Commands' below and the section `Completion System
Configuration' above.
_ignored
The ignored-patterns style can be set to a list of patterns
which are compared against possible completions; matching ones
are removed. With this completer those matches can be rein‐
stated, as if no ignored-patterns style were set. The completer
actually generates its own list of matches; which completers are
used for this is determined in the same way as for the _prefix
completer.
The single-ignored style is used if only one match could be gen‐
erated. It can be set to show to prevent that match from being
displayed or inserted into the line, or it can be set to menu,
in which case the single match and the original string from the
line will be offered in a menu completion.
_list This completer allows one to delay the insertion of matches
until completion is attempted a second time without the word on
the line being changed. On the first attempt, only the list of
matches will be shown. It is affected by the styles condition
and word, see the section `Completion System Configuration'
above.
_match This completer is intended to be used after the _complete com‐
pleter. It allows one to give patterns on the command line and
to complete all strings matching these patterns from the set of
possible completions for the context the cursor is in, without
having to set the GLOB_COMPLETE option.
Normally this will be done by taking the pattern from the line,
inserting a `*' at the cursor position and comparing the result‐
ing pattern with the possible completions generated. However,
if the match-original style has a value of only, no `*' will be
inserted. If match-original has any other non-empty string as
its value, this completer will first try to generate matches
without, then with a `*' inserted at the cursor position.
The generated matches will be offered in a menu completion
unless the insert-unambiguous style is set to `true'. In this
case menu completion will only be started if no unambiguous
string could be generated that is at least as long as the origi‐
nal string.
Note that the matcher specifications defined globally or used by
the completion functions will not be used.
_menu This completer is a simple example function implemented to show
how menu completion can be done in shell code. It should be
used as the first completer and has the effect of making the
code perform menu completion. 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 sepa‐
rately-bound completion command). It allows the ordinary com‐
pletion keys to continue to use the list of completions thus
generated, instead of producing a new list of ordinary contex‐
tual 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 the section `Completion Sys‐
tem Configuration' above.
_prefix
This completer can be used to try completion with the suffix
(everything after the cursor) ignored. In other words, the suf‐
fix will not be considered to be part of the word to complete
and hence does not need to be matched. It uses the completer
style to decide which other completers to call to try to gener‐
ate matches. If this style is unset, the list of completers set
for the current context is used -- except, of course, the _pre‐
fix completer itself. Furthermore, if this completer appears
more than once in the list of completers only those completers
not already tried by the last 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. If you want to use _prefix as the last resort
and try only normal completion, you can use:
zstyle ':completion:*' completer _complete ... _prefix
zstyle ':completion::prefix:*' completer _complete
The add-space style is also used. 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.
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; `$', environ‐
ment variables; `@', host names; `/', file names; `~' user
names. In bash, the binding preceeded by `\e' gives completion,
and preceeded 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 con‐
textual 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_word (^Xe)
Performs expansion on the current word: equivalent to the stan‐
dard expand-word command, but using the _expand completer.
Before calling it, the function field is set to `expand-word'.
Unlike _expand this uses a `1' (one) as the default value for
the substitute and glob styles, so both types of expansion will
normally be performed.
_history_complete_word (\e/)
Complete words from the shell's command history. This uses the
list, remove-all-dups, sort, and stop styles.
_most_recent_file (^Xm)
Complete the name of the most recently modified file matching
the pattern on the command line (which may be blank). If given
a numeric argument N, complete the Nth most recently modified
file. Note the completion, if any, is always unique.
_next_tags (^Xn)
This command alters the set of matches used to that for the next
tag, or set of tags, either as given by the tag-order style or
as set by default; these matches would otherwise not be avail‐
able. 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 argu‐
ments will be called to generate the completions. Unambiguous
parts of the function name will be completed automatically (nor‐
mal 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 argu‐
ment.
_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 func‐
tions called, which in turn is determined by the user's own
styles and other settings.
_complete_debug (^X?)
This widget performs ordinary completion, but captures in a tem‐
porary file a trace of the shell commands executed by the com‐
pletion system. Each completion attempt gets its own file. A
command to view each of these files is pushed onto the editor
buffer stack.
_complete_tag (^Xt)
This widget completes symbol tags created by the etags or ctags
programmes (note there is no connection with the completion sys‐
tem'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 $TAGS‐
FILE or $tagsfile respectively. The corresponding completion
tags used are etags and vtags, after emacs and vi respectively.
UTILITY FUNCTIONS
Descriptions follow for utility functions that may be useful when writ‐
ing completion functions. Most of these reside in the Core subdirec‐
tory. Like the example functions for commands in the distribution, the
utility functions generating matches all follow the convention of
returning zero if they generated completions and non-zero if no match‐
ing completions could be added.
When writing completion functions or other ZLE widgets that call com‐
pletion, it might be interesting to know about two more features
offered by the _main_complete function. The arrays compprefuncs and
comppostfuncs may be set to contain names of functions that are to be
called immediately before or after completion has been tried. The func‐
tions will only be called once, unless they put themselves into the
arrays again.
_all_labels [ -12VJ ] tag name descr [ command args ... ]
This is a convenient interface to the _next_label function
below, implementing the loop shown in the _next_label example.
The command is the one that should be called to generate the
matches. The options stored in the parameter name will automati‐
cally be inserted into the args given to the command. Normally,
they are put directly after the command, but if one of the args
is a single hyphen, they are inserted directly before that. If
the hyphen is the last argument, that will be removed from the
argument list before the command is called. This allows to use
_all_labels in almost all cases where the matches can be gener‐
ated 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 com‐
padd with additional options which will take precedence over
those generated by _all_labels.
_alternative [ -C name ] specs ...
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 above.
The tags to use and the action to perform if a tag is requested
are described using the specs which are of the form:
`tag:descr:action'. The tags are offered using _tags and if the
tag is requested, the action is executed with the given descrip‐
tion descr. The actions supported are those used by the _argu‐
ments function (described below), without the `->state' and
`=...' forms.
For example, the action may be a simple function call. With that
one could do:
_alternative \
'users:user:_users' \
'hosts:host:_hosts'
to offer usernames and hostnames as possible matches (which are
generated by the _users and _hosts functions respectively).
Note that, like _arguments this will also use _all_labels to
execute the actions, so one doesn't need to call that explicitly
unless another tag is to be used, for example in a function
called from _alternative.
Like _tags this function supports the -C option to give a dif‐
ferent name for the argument context field.
_arguments spec ...
This function can be used to complete words on the line by
describing the options and arguments which may be passed to the
command for which completion is being performed. The descrip‐
tion is given as arguments to this function, with each spec
describing one option or normal argument of the command. The
forms of spec understood are:
n:message:action
n::message:action
This describes the n'th normal argument. The message
will be printed above the matches generated and the
action says what can be completed in this position (see
below). If there are two colons before the message, this
describes an optional argument.
:message:action
::message:action
Like the previous one, but describing the next argument.
I.e. if you want to describe all arguments a command can
get, you can leave out the numbers in the description and
just use this form to describe them one after another in
the order they have to appear on the line.
*:message:action
*::message:action
*:::message:action
This describes how arguments (usually non-option argu‐
ments, those not beginning with - or +) are to be com‐
pleted when no description with one of the first two
forms was given. This also means that any number of argu‐
ments can be completed.
With two colons before the message, the words special
array and the CURRENT special parameter are modified to
refer only to the normal arguments when the action is
executed or evaluated. With three colons before the mes‐
sage they are modified to refer only to the normal argu‐
ments covered by this description.
optspec[description ...]
This describes an option and (if description is given)
the arguments that have to come after the option. If no
description is given, this means to offer only the option
name as a possible completion in the right places. (Note
that the brackets, above, around description, indicate
that zero or more descriptions may appear; but the brack‐
ets are not themselves part of this format. If brackets
are used, they are part of the optspec; see below.)
In the descriptions below, the option names represented
by optname are normally taken to be multi-character
names, and a word from the line is considered to contain
only one option (or none). By giving the -s option to
_arguments before the first spec, each optname is consid‐
ered to be a single character and each word from the line
may contain more than one such option letter. However,
words beginning with two hyphens (like `--prefix') are
still considered to contain only one option name. This
allows the use of the `-s' option to describe single-let‐
ter options together with such long option names.
The forms of optspec are:
*optspec
If the option may be given more than once, a star
(`*') must be added in front of one of the follow‐
ing forms of optspec. Otherwise, if the option is
already on the line and to the left of the cursor,
it is not offered as a possible completion again.
-optname
+optname
In the simplest form the optspec is just the
option name beginning with a minus or a plus sign,
such as `-foo'. The first argument for the option
(if any) must follow as a separate word directly
after the option.
If the command accepts the option with either a
leading minus or a leading plus sign, use either
`-+optname' or `+-optname' to define both variants
at once.
In all the following forms, the leading `-' may be
replaced or paired with `+' in this way.
-optname-
The first argument of the option must come
directly after the option name in the same word,
as in `-foo-:...'.
-optname+
The first argument may appear immediately after
optname in the same word, or may instead appear as
a separate word after the option.
-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 equal sign.
-optname=-
The argument to the option must appear after an
equal 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 of optspec by enclosing it in
brackets, as in `-q[query operation]'.
The verbose style is used to decide if these
explanation strings should be displayed with the
option in a completion listing.
If no bracketed explanation string is given but
the auto-description style is set and only one
argument is described for this optspec, the value
of the style is displayed, with any appearance of
the sequence `%d' in it replaced by the message of
the first description that follows the optspec;
see below.
Note that the special meaning of a leading or trailing - or + in
optspec means that when the command to be completed accepts
options like `-+' or `-=', the second character has to be quoted
with a backslash, as in `-\+'.
Each description following an optspec must take one of the fol‐
lowing forms:
:message:action
::message:action
Describes a mandatory argument with one colon, or an
optional argument with two colons. As in other forms of
spec, the message will be printed above the matches gen‐
erated and the action says what can be completed in this
position.
:*pattern:message:action
:*pattern::message:action
:*pattern:::message:action
This describes multiple arguments. Only the last
description may be given in this form. If the pattern is
empty (i.e., :*:), all following words on the line are to
be completed as described by the action; otherwise, all
words up to a word matching the pattern are to be com‐
pleted using the action.
When the message is preceded by two colons, the words
special array and the CURRENT special parameter are modi‐
fied during the execution or evaluation of the action to
refer only to the words after the option. When preceded
by three colons, they are modified to refer only to the
words covered by this description.
Note that only one such `:*'-specification is useful and
no other argument specification may be given after it.
To include a colon in any optname, message, or action anywhere above,
it has to be preceded by a backslash, as `\:'.
Each of the six forms of spec (yes, there are six, keep track of the
nestings) may be preceded by a list of option names and argument num‐
bers with which the option or argument described is mutually exclusive.
This list is given in parentheses, as in `(-two -three 1)-one:...' or
`(-foo):...'. In the first example, the options `-two' and `-three'
and the first argument will not be offered as possible completions if
the option `-one' is on the line before the cursor, and in the second
example the option `-foo' will not be offered if the argument described
by the specification is on the line.
The list may also contain a single star (*) as one of its elements to
specify that the description for the rest arguments (i.e. a specifica‐
tion of the form `*:...') should not be used, a colon (:) to specify
that the descriptions for all normal (non-option-) arguments should not
be used and a hyphen (-) to specify that the descriptions for all
options should not be used. This paragraph desperately needs rewrit‐
ing.
In every case above, the action determines how the possible completions
should be generated. In places where no sensible matches can be gener‐
ated, the action should consist of only a space. This will make the
message be displayed but no possible completions listed. Note that even
in this case the colon at the end of the message is needed. The only
case where it can be left is when neither a message, nor a action is
given.
Except for the `->string' form below, the action will be executed by
calling the _all_labels function to process all tag labels, so one
doesn't need to call that explicitly unless another tag is to be used,
for example in a function called in the action.
When only one of a fixed set of strings can be completed, the action
can consist of these strings as a list in parentheses, as in:
:foo:(foo bar baz)
Such a list in doubled parentheses should contain strings consisting of
the string to complete followed by `\:' and a description, as in:
:foo:((a\:bar b\:baz))
The matches will be listed together with their descriptions if the
description style for the values tag is set.
An action of the form `->string' is used by functions that implement a
state machine. In this case, the `string's (with all leading and trail‐
ing spaces and tabs removed) of all actions that have to be used will
be stored in the global array state and the function returns with a
return value of 300 (to make it distinguishable from other return val‐
ues) after setting the global `context', `line' and `opt_args' parame‐
ters as described below, and without resetting any changes made to the
special parameters such as PREFIX and words.
Note that this means that a function calling _arguments with at least
one action containing such a `->string' has to declare appropriate
local parameters as in:
local context state line
typeset -A opt_args
This will ensure that _arguments does not create unused global parame‐
ters.
A string in braces is evaluated to generate the matches and if the
action does not begin with an opening parentheses or brace, it is also
split into separate words and executed. If the action starts with a
space, this list of words will be invoked unchanged, otherwise it will
be invoked with some extra strings placed after the first word which
can be given as arguments to the compadd builtin command and which make
sure that the message given in the description will be shown above the
matches. These arguments are taken from the array parameter expl which
will be set up before executing the action and hence may be used in it
(normally in an expansion like `$expl[@]').
If the action starts with `= ' (an equal sign followed by a space),
_arguments will insert the contents of the argument field of the cur‐
rent context as the new first element in the words special array and
increments the value of the CURRENT special parameter. In other words,
it inserts a dummy element in the words array and makes CURRENT still
point to the word in that array where the cursor is. This is only
really useful when used with one of the forms that make _arguments mod‐
ify the words array to contain only some of the words from the line,
i.e. one of the argument description forms where the message is pre‐
ceded by two or three colons. For example, when the function called in
the action for such an argument itself uses _arguments, the dummy ele‐
ment is needed to make that second call to _arguments use all words
from the restricted range for argument parsing. Without the inserted
dummy element, the first word in the range would be taken (by the sec‐
ond _arguments) to be the command name and hence ignored.
During the evaluation or execution of the action the array `line' will
be set to the command name and normal arguments from the command line,
i.e. to the words from the command line excluding all options and their
arguments. These are stored in the associative array `opt_args', using
the option names as keys and their arguments as the values. For options
that have more than one argument these are given as one string, sepa‐
rated by colons. All colons in the original arguments are preceded with
backslashes.
The parameter `context' (set only in the calling function when using an
action of the form `->string', not during the evaluation of other
actions) is set to the automatically created context names. These are
either strings of the form `option-opt-n' for the n'th argument of the
option -opt, or strings of the form `argument-n' for the n'th argument
(for rest arguments the n is the string `rest'). For example, when com‐
pleting the argument of the -o option, the name is `option-o-1' and for
the second normal (non-option-) argument it is `argument-2'.
Also, during the evaluation of the action, the context name in the cur‐
context parameter is changed by appending the same string that is
stored in the context parameter.
It is also possible to specify multiple sets of options and arguments
with the sets separated by single hyphens. The specifications before
the first hyphen are shared by all sets given after the first hyphen.
The first word in every other set gives the name of the set. This name
may appear in exclusion lists in the specifications, either alone or
before one of the possible values described above (with a `-' between
the name and the rest).
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 com‐
pletions. When it contains `-d' or an argument, the option `-c' will
not be completed any more, but if `-a' is given, both sets will still
be considered valid, because it appears before the first hyphen, so
both sets contain this option.
If the name-string is of the form `(name)' then all specifications in
the set have an implicit exclusion list containing the name of the set,
i.e. all specifications are mutual exclusive with all other specifica‐
tions in the same set. This is useful for defining multiple sets of
options which are mutually exclusive and in which the options are
aliases for each other. E.g.:
_arguments \
-a -b \
- '(compress)' \
{-c,--compress}'[compress]' \
- '(uncompress)' \
{-d,--decompress}'[decompress]'
To simplify the specifications for commands with standard option pars‐
ing, the options -A and -S may be given. With -A no options will be
completed after the first non-option argument on the line. With -S, no
option will be completed after a `--' on the line and this argument
will otherwise be ignored.
Note that using multiple sets will be slower than using only one set
because the completion code has to parse the command line once for
every set. So more than one set should only be used if the command syn‐
tax is too complicated. Note also that a option specification with
rest-arguments (as in `-foo:*:...') often allows to avoid the use of
multiple sets.
Another option supported is `-O name'. The name will be taken as the
name of an array and its elements will be given to functions called to
generate matches when executing the actions. For example, this allows
one to give options for the compadd builtin that should be used for all
actions.
Also, the -M option followed by a string may be given before the first
description. The string will be used as the match specification when
completing option names and values instead of the default `r:|[_-]=*
r:|=*'.
Finally, the option -C can be given to make _arguments modify the cur‐
context parameter when a action of the form `->state' is used. This
parameter is used to keep track of the current context and in this case
it (and not the parameter context as explained above) has to be made
local to make sure that calling functions don't use the modified value.
Also, the local version of curcontext has to be initialised with the
old value as in:
local curcontext="$curcontext"
The function can also be made to automatically complete long options
for commands that support the `--help' option as, for example, most of
the GNU commands do. For this, the string `--' must be given as one
argument and if it is, the command from the line is invoked with the
`--help' option and its output is parsed to find possible option names.
Note that this means that you should be careful to make sure that this
feature is not used for a command that does not support this option.
For such automatically found options that get an argument after a `=',
the function also tries to automatically find out what should be com‐
pleted as the argument. The possible completions for option-arguments
can be described with the arguments after the `--' (which are not used
as described above). Each argument contains one description of the form
`pattern:message:action'. The message and the action have the same for‐
mat as for the normal option descriptions described above. The action
will be executed to complete arguments of options whose description in
the output of the command from the line with the `--help' option
matches the pattern. For example:
_arguments -- '*\*:toggle:(yes no)' \
'*=FILE*:file:_files' \
'*=DIR*:directory:_files -/'
Here, `yes' and `no' will be completed as the argument of options whose
description ends in a star, file names for options that contain the
substring `=FILE' in the description, and paths for options whose
description contains `=DIR'. In fact, the last two patterns are not
needed since this function always completes files for option descrip‐
tions containing `=FILE' and paths for option descriptions that contain
`=DIR' or `=PATH'. These builtin patterns can be overridden by patterns
given as arguments, however.
Note also that _arguments tries to find out automatically if the argu‐
ment for an option is optional. If it fails to automatically detect
this, the colon before the message can be doubled to tell it about this
as described for the normal option descriptions above.
If the pattern ends in `(-)', this will removed from the pattern and
the action will be used only directly after the `=', not in the next
word. I.e., this is like a normal specification as descrobed above
using `=-'.
The option `-i patterns' (which must be given after the `--') can be
used to give patterns for options which should not be completed. The
patterns can be given as the name of an array parameter or as a literal
list in parentheses. E.g. `-i "(--(en|dis)able-FEATURE*)"' will make
the options `--enable-FEATURE' and `--disable-FEATURE' be ignored. The
option `-s pairs' (again, after the `--') can be used to describe
option aliases. Each pair consists of a pattern and a replacement. E.g.
some configure-scripts describe options only as `--enable-foo', but
also accept `--disable-foo'. To allow completion of the second form,
one would use `-s "(#--enable- --disable-)"'.
Example:
_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
one gets one argument described as `left border' for which no comple‐
tion will be offered because of the empty action. The argument may come
directly after the `-l' or it may be given as the next word on the
line. The `-format' option gets one argument (in the next word)
described as `paper size' for which only the strings `letter' and `A4'
will be completed. The `-copy' option differs from the first two in
that it may appear more than once on the command line and in that it
accepts two arguments. The first one is mandatory and will be completed
as a filename. The second one 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 one describes the first argument as a `postscript file' and
makes files ending in `ps' or `eps' be completed. The last description
says that all other arguments are `page numbers' but does not give pos‐
sible completions.
_call tag string ...
This function is used in places where a command is called, mak‐
ing it possible for the user to override the default command
call. It looks up the command style with the supplied tag. If
the style is set, its value is used as the command to execute.
In any case, the strings from the call to _call or from the
style are concatenated with spaces between them and the result‐
ing string is evaluated. The return value is the return value
of the command called.
_combination [ -s pattern ] tag style specs ... field opts ...
This function is used to complete combinations of values such as
pairs of hostnames and usernames. The possible values will be
taken from the style whose name is given as the second argument.
The first argument is the tag to use to do the lookup.
The style name should consist of multiple parts separated by
hyphens which are then used as field names. Known values for
such fields can be given after the second argument in arguments
of the form `field=pattern'. The first argument without a equal
sign is taken as the name of the field for which completions
should be generated.
The matches generated will be taken from the value of the style.
These values should contain the possible values for the combina‐
tions where the values for the different fields are separated by
colons or characters matching the pattern given after the -s
option to _combination; normally this is used to define charac‐
ter classes like the `-s "[:@]"' used for the users-hosts style.
Only the values for the requested fields for which the patterns
given in the `field=pattern' match the respective fields in the
strings from the style value are generated as possible matches.
If no style with the given name is defined for the given tag but
a function named with the name of the requested field preceded
by an underscore is defined, that function will be called to
generate the matches. This is also done if none of the strings
in the value of the style match all the patterns given as argu‐
ments.
If the same name is used for more than one field, in both the
`field=pattern' and the argument that gives the field name to
complete for, the number of the field (starting with one) may be
given after the fieldname, separated from it by a colon.
All arguments after the requested field name are passed to com‐
padd when generating matches from the style value, or to the
functions for the fields if they are called.
_compalso names ...
This function looks up the definitions for the context and com‐
mand names given as arguments and calls the handler functions
for them if there is a definition (given with the compdef func‐
tion). For example, the function completing inside subscripts
might use `_compalso -math-' to include the completions gener‐
ated for mathematical environments.
_describe [ -o ] descr name1 [ name2 ] opts ... -- ...
This function is useful for preparing a list of command options
or arguments, together with their descriptions descr, as
matches. Multiple groups separated by -- can be supplied,
potentially with different completion options opts.
The descr is taken as a string to display above the matches if
the format style for the descriptions tag is set. After this
come one or two names of arrays followed by options to pass to
compadd. The first array contains the possible completions with
their descriptions in the form `completion:description'. If a
second array is given, it should have the same number of ele‐
ments as the first one and the corresponding elements are added
as possible completions instead of the completion strings from
the first array. The completion list will retain the descrip‐
tions from the first array. Finally, a set of completion
options can appear.
If the option `-o' appears before the first argument, the
matches added will be treated as option names (typically follow‐
ing a `-', `--' or `+' on the command line). This makes
_describe use the prefix-hidden, prefix-needed and verbose
styles to find out if the strings should be added at all and if
the descriptions should be shown. Without the `-o' option, only
the verbose style is used.
_describe uses the _all_labels function to generate the matches,
so it does not need to appear inside a loop over tag labels.
_description [ -12VJ ] tag name descr [ specs ... ]
This function is called before completions are added (typically
by a call to compadd); it tests various styles and arranges for
any necessary options to be passed on to compadd. The styles
are tested in the current context using the given tag; options
are put into the array called name for passing on to compadd;
the description for the current set of matches is passed in
descr. The styles tested are: format (which is first tested for
the given tag and then for the descriptions tag if that isn't
defined), hidden, matcher, ignored-patterns and group-name (the
last are tested only for the tag given as the first argument).
This function also calls the _setup function which tests some
more styles.
The string returned by the format style (if any) will be modi‐
fied so that the sequence `%d' is replaced by the descr given as
the third argument. If _description is called with more than
three arguments, the additional specs should be of the form
`char:str' and every appearance of `%char' in the format string
will be replaced by string.
The options placed in the array will also make sure that the
matches are placed in a separate group, depending on the value
of the group-name style. Normally a sorted group will be used
for this (with the `-J' option), but if a option starting with
`-V', `-J', `-1', or `-2' is given, that option will be included
in the array, so that it is possible to make the group 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 sys‐
tem use a similar format; this ensures that user-specified
styles are correctly passed down to the builtins which implement
the internals of completion.
_funcall return name [ args ... ]
If a function name exists, it is called with the arguments args.
Unless it is the empty string or a single hyphen, return is
taken as the name of a parameter and the return status from the
called function is stored in it. The return value of _funcall
itself is zero if the function name exists and was called and
non-zero otherwise.
_message [ -r ] descr
The descr is used like the third argument to the _description
function. However, the resulting string will always be shown
whether or not matches were generated. This is useful to display
help texts in places where no completions can be generated auto‐
matically.
This function also uses the format style for the messages tag in
preference to the format style for the descriptions tag. The
latter is used only if the former is unset.
If the -r option is given, no style is used and the descr is
used literally as the string to display. This is only used in
cases where that string is taken from some pre-processed argu‐
ment list containing an expanded description.
_multi_parts sep array
This function receives two arguments: a separator character and
an array. As usual, the array may be either the name of an
array parameter or a literal array in the form `(foo bar)' (i.e.
a list of words separated by white space in parentheses). With
these arguments, this function will complete to strings from the
array where the parts separated by the separator character are
completed independently. For example, the _tar function from
the distribution caches the pathnames from the tar file in an
array, and then calls this function to complete these names in
the way normal filenames are completed by the _path_files func‐
tion, by using `_multi_parts / patharray'.
If the -i option is present, then any time there is a unique
match it will immediately be inserted even if that requires
additional separators to be inserted as well. When completing
from a fixed set of possible completions which are really words,
this is often the expected behaviour; however, if _multi_parts
should behave like completing pathnames, the -i option should
not be used.
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 [ -12VJ ] tag name descr [ options ... ]
This function should be called repeatedly to generate the tag
labels. On each call it will check if another tag label is to be
used and, if there is at least one, zero is returned. If no more
tag labels are to be used, a non-zero status is returned.
The -12JV options and the first three arguments are given to the
_description function using the tag label instead of the first
argument as appropriate. The options given after the descr
should be other options to be used for compadd or whatever func‐
tion is to be called to add the matches. _next_label will store
these options in the parameter whose name is given as the second
argument. This is done in such a way that the description given
by the user to the tag-order style is preferred over the one
given to _next_label.
Note that this function must not be called without a previous
call to _tags or _requested because it uses the tag label for
the current tag found by these functions.
A normal use of this function for the tag labels of the tag foo
looks like this:
local expl ret=1
...
if _requested foo; then
...
while _next_label foo expl '...'; do
compadd "$expl[@]" ... && ret=0
done
...
fi
return ret
_normal
This function is used for normal command completion. It has two
tasks: completing the first word on the command line as the name
of a command, and completing the arguments to this command. In
the second case, the name of the command is looked up to see if
special completions exists, including completions defined for
patterns which match the name. If none is found, completion is
performed for the context -default-.
The function can also be called by other completion functions
which need to treat a range of words as a command line. For
example, the function to complete after the pre-command speci‐
fiers such as nohup removes the first word from the words array,
decrements the CURRENT parameter, then calls _normal again, with
the effect that `nohup cmd ...' is treated the same way was
`cmd ...'.
If the command name matches a pattern, the parameter _compskip
is checked after the call to the corresponding completion func‐
tion. This has the same effect here as in the -first- context:
if it is set, no more completion functions are called even if
there are no matches so far.
_parameters
This should be used to complete parameter names. All arguments
are passed unchanged to the compadd builtin.
_path_files and _files
The function _path_files is used throughout the completion sys‐
tem 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 function _files uses the file-patterns style and calls
_path_files with all the arguments it was passed except for -g
and -/. These two options are used depending on the setting of
the file-patterns style.
The options accepted by both _path_files and _files are:
-f Complete all filenames. This is the default.
-/ Specifies that only directories should be completed.
-g pattern
Specifies that only files matching the pattern should be
completed.
-W paths
Specifies path prefixes that are to be prepended to the
string from the line to generate the filenames but that
should not be inserted in the line or shown in a comple‐
tion listing. Here, paths may be the name of an array
parameter, a literal list of paths enclosed in parenthe‐
ses or an absolute pathname.
-F This option from the compadd builtin gives direct control
over which filenames should be ignored. If the option is
not present, the ignored-patterns style is used.
These functions also accept the `-J', `-V', `-1', `-2', `-n',
`-X', `-M', `-P', `-S', `-q', `-r', and `-R' options from the
compadd builtin.
Finally, the _path_files function uses the styles expand,
ambiguous and special-dirs and file-sort.
_options
This can be used to complete option names. It uses a matching
specification that ignores a leading `no', ignores underscores
and allows the user to type upper-case letters which will match
their lower-case counterparts. All arguments passed to this
function are propagated unchanged to the compadd builtin.
_regex_arguments name specs ...
This function is a compiler to generate a completion function.
The first argument specifies the name of the generated function
while the remaining arguments specify a completion as a set of
regular expressions with actions. The generated function has
the structure of a finite-state machine whose states corresponds
to the state (i.e. the context) of the completion. This state
machine uses a command line, which comes from concatenating the
words array up to the current cursor position using null charac‐
ters as separators with no extra quotation. This is analysed
and at the end the appropriate action is executed.
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 primitive element, corresponding to one state
of the compiled state machine. The state is entered if
`(#b)((#B)pattern)(#B)lookahead*' matches the command
line string. If it is matched, `guard' is evaluated and
its return status is examined; if this is successful, the
state is entered, else the test fails and other candi‐
dates are tried. The pattern string `[]' is guaranteed
never to match.
If the test succeeds and the state is entered, the left
part of the command line string matched as pattern is
removed and the next state is tried, proceeding from
inside to outside and from left to right.
If no test succeeds and the remaining command line string
contains no null character, the completion target is
restricted to the remainder of the command line string
and actions for the target are executed. In this case,
nothing is actually removed from the command line string
so that any previous or neighbouring state may also have
actionss. actionss evaluation are ordered by the
tag-order style and specified tag by _alternative. So,
various format supported by _alternative can be used in
action. descr is used for set up the array parameter
expl.
/pattern/+ [%lookahead%] [-guard] [:tag:descr:action]
This is similar to `/pattern/ ...' but the left part of
command line string is also considered as part of the
completion target.
/pattern/- [%lookahead%] [-guard] [:tag:descr:action]
This is similar to `/pattern/ ...' but the actions of the
current and previous states are ignored even if the fol‐
lowing state's `pattern' matches the empty string.
( spec )
This groups specs.
spec # This allows any number of repetitions of spec.
spec spec
This represents the concatenation of two specs.
spec | spec
Either of the two specs can be matched.
_requested [ -12VJ ] tag [ name descr [ command args ... ] ]
This function is called to decide whether a tag already regis‐
tered by a call to _tags (see below) is requested and hence com‐
pletion should be performed for it; it returns status zero if
the tags is requested and non-zero otherwise. This will usually
be done in a loop such as the following:
_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 specify a set of tags to be tested at the same time in
the tag-order parameter.
If the name and the descr are given, _requested calls the
_description function with these arguments, including the
options.
If the command is given, the _all_labels function will be called
immediately with the same arguments. This is often useful to do
both the testing of the tag, getting the description for the
matches and adding the matches at once. 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
_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 passes the `-V', `-J', `-1', `-2', `-n', `-X',
`-M', `-P', `-S', `-r', `-R', and `-q' options and their argu‐
ments to the compadd builtin used to add the matches.
_set_options and _unset_options
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_com‐
plete 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 options are not generally used by the completion
system.
_setup tag
This function expects a tag as its argument and sets up the spe‐
cial parameters used by the completion system appropriately for
the tag, using styles such as list-colors and last-prompt.
Note that this function is called automatically from _descrip‐
tion so that one normally doesn't have to call it explicitly.
_sort_tags tag ...
No such function is actually used by the completion system; as
mentioned above for the tag-order style, it is only provided to
show how functions that sort tags can be implemented.
Inside such functions the name of the current context can be
accessed using the curcontext parameter. For example, the func‐
tion used in command position (called _command_names) in the
completion can generate names of external and builtin commands,
names of shell functions, aliases and parameters and reserved
words.
Example:
_sort_tags() {
case $curcontext in
(*:-command-:*)
comptry commands functions
comptry builtins aliases
;;
(*)
.comptry "$@"
;;
esac
return 1
}
Every call to the comptry builtin command gives a set of tags to
use; as soon as the completion system produces matches for one
set, subsequent sets have no effect. Hence in the example this
means that in command position on the first attempt only names
of external commands and shell functions will be generated (the
first call to comptry). If none of those names match the string
from the command line the completion function will generate
names of builtin commands and aliases as possible matches (the
second call to comptry).
For all other context names the second case-pattern matches, so
that normally the completion functions will try all tags
offered. The return value means that the calling function,
_tags, will not use all offered tags as a default, so in the
first case names or parameters and reserved words will never be
completed.
In any context the function may call comptry as often as neces‐
sary. Also, any string may be given as an argument, even if no
tag with that name was offered by the completion function. This
allows one to give a preferred ordering for some common tag sets
without having to worry about sensible patterns for context
names. For example, many completion functions can generate both
arguments and option names for commands. These functions nor‐
mally use the tags like argument-num, option-name-num and
options. Depending on your preference you may write in your
sorting function:
_sort_tags() {
comptry -m '(|*-)argument-* (|*-)option-* options'
case $curcontext in
...
esac
}
or
_sort_tags() {
comptry -m '(|*-)argument-* (|*-)option-*'
comptry options
case $curcontext in
...
esac
}
The former always adds both the matches for the argument and the
option names as possible matches. The latter forces matches for
the arguments to be preferred. In this case option names are
only generated as matches if the string on the line produces no
possible completion for arguments; normally you would have to
type the hyphen the option names start with yourself in order to
see the list of option names that can be completed.
With the -s option, each tag given to comptry will be put in a
separate set. With the -m option, the arguments are treated in
the same way as the the values for the tag-order style (except
for the `!...', `-' and `foo()' forms).
_tags [ -C name [ tags ... ] ]
If called with arguments, these are taken as the names of the
tags for the types of matches the calling completion function
can generate in the current context. These tags are stored
internally and sorted by using the tag-order style. Following
calls to this function without arguments from the same function
will then select the first, second, etc. set of tags requested
by the user. To test if a certain tag should be tried, the
_requested function has to be called (see above).
The return value is zero if at least one of the tags is
requested and non-zero otherwise.
This function also accepts the -C option followed by a name.
This name is temporarily (i.e. not visible outside _tags) stored
in the argument field of the context name in the curcontext
parameter. This allows to make _tags use a more specific context
name without having to change and reset the curcontext parameter
(which would otherwise have the same effect).
_wanted [ -C name ] [ -12VJ ] tag name descr command args ...
In many contexts, completion will one 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.
Like _requested, it should be passed arguments as for _descrip‐
tion. It calls _tags with the given tag and if that returns
zero (so that the tag is requested by the user) it calls
_description. Hence to offer only one tag and immediately use
the description generated:
_wanted tag expl 'description' \
compadd matches...
Unlike _requested, however, _wanted cannot be called without the
command. This is because _wanted also implements the loop over
the tags, not just the one for the labels; conversely, it should
not be called in the middle of a _tags loop.
Like _tags this function supports the -C option to give a dif‐
ferent name for the argument context field.
_values specs ...
This is used to complete values (strings) and their arguments or
lists of such values. It can be used in two ways.
If the first argument is the option `-O name', this will be used
in the same way as by the _arguments function, in other words
the elements of the name array will be given to calls to compadd
and when executing an action.
Otherwise, if the first argument (or the first argument after
the `-O name' option if that is used) is the option `-s', the
next argument is used as the character that separates multiple
values. Thus the values completed appear in the same word on
the command line, unlike completion using _arguments.
The first argument (after the options and separator character if
they are given) is used as a string to print as a description
before listing the values.
All other arguments describe the possible values and their argu‐
ments 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 and that
values can have only one argument.
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' for which no action is specified so
that it will not be completed automatically. The `(two)' at the
beginning says that if the value `one' is on the line, the value
`two' will not be considered to be a possible completion any‐
more. Finally, the last value (`two') is described as `another
number' and takes an optional argument described as `second
count' which will be completed from the strings `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 current context name while executing the
action. Here this name is just the name of the value for which
the argument is completed.
To decide if the descriptions for the values (not those for the
arguments) should be printed, the style verbose is used.
One last difference from _arguments is that this function uses
the associative array val_args to report values and their argu‐
ments, although otherwise this is the same as the opt_args asso‐
ciation used by _arguments. This also means that the function
calling _values should declare the state, line, context and
val_args parameters as in:
local context state line
typeset -A val_args
when using an action of the form `->string'. With this function
the context parameter will be set to the name of the value whose
argument is to be completed.
Like _arguments, _values supports the -C option in which case
you have to make the parameter curcontext local instead of con‐
text (as described above).
COMPLETION DIRECTORIES
In the source distribution, the files are contained in various subdi‐
rectories of the Completion directory. They may have been installed in
the same structure, or into one single function directory. The follow‐
ing 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.
Core The core scripts and functions. You will certainly need these,
though will probably not need to alter them. Many of these are
documented above.
Base Other functions you will almost certainly want if you are going
to use any of the standard completion functions. You may want
to edit some of these files.
Builtins
Functions for completing arguments of shell builtin commands and
utility functions for this. Some of these are also used by
functions from the User directory.
User 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 ver‐
sion of a command is present. For example, completion for the
mount command tries to determine the system it is running on,
while completion for many other utilities try to decide whether
the GNU version of the command is in use, and hence whether the
--help option is supported..
Commands
Functions which implement special types of completion to be
bound to keystrokes rather than called by context.
zsh 3.1.9 June 5, 2000 ZSHCOMPSYS(1)
