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ZSHCOMPSYS(1)		     General Commands Manual		   ZSHCOMPSYS(1)

NAME
     zshcompsys - zsh completion system

DESCRIPTION
     This  describes the shell code for the `new' completion system, referred to
     as compsys.  It is written in shell functions based  on  the  features  de-
     scribed in zshcompwid(1).

     The  features are contextual, sensitive to the point at which completion is
     started.  Many completions are already provided.  For this reason,  a  user
     can  perform  a  great many tasks without knowing any details beyond how to
     initialize the system, which is described below in INITIALIZATION.

     The context that decides what completion is to be performed may be
     *	    an argument or option position: these describe the position  on  the
	    command  line  at which completion is requested.  For example `first
	    argument to rmdir, the word being completed names a directory';

     *	    a special context, denoting an element in the shell's  syntax.   For
	    example `a word in command position' or `an array subscript'.

     A full context specification contains other elements, as we shall describe.

     Besides  commands names and contexts, the system employs two more concepts,
     styles and tags.  These provide ways for the user to configure the system's
     behaviour.

     Tags play a dual role.  They serve  as  a	classification	system	for  the
     matches,  typically  indicating a class of object that the user may need to
     distinguish.  For example, when completing arguments of the ls command  the
     user may prefer to try files before directories, so both of these are tags.
     They also appear as the rightmost element in a context specification.

     Styles  modify  various operations of the completion system, such as output
     formatting, but also what kinds of completers are used (and in what order),
     or which tags are examined.  Styles may accept arguments  and  are  manipu-
     lated using the zstyle command described in zshmodules(1).

     In  summary,  tags  describe what the completion objects are, and style how
     they are to be completed.	At various points of execution,  the  completion
     system  checks what styles and/or tags are defined for the current context,
     and uses that to modify its behavior.  The full description of context han-
     dling, which determines how tags and other elements of the  context  influ-
     ence  the behaviour of styles, is described below in COMPLETION SYSTEM CON-
     FIGURATION.

     When a completion is requested, a dispatcher function is  called;	see  the
     description  of _main_complete in the list of control functions below. This
     dispatcher decides which function should be called to produce  the  comple-
     tions,  and calls it. The result is passed to one or more completers, func-
     tions that implement individual completion strategies:  simple  completion,
     error correction, completion with error correction, menu selection, etc.

     More  generally, the shell functions contained in the completion system are
     of two types:
     *	    those beginning `comp' are to be called directly; there are  only  a
	    few of these;

     *	    those  beginning  `_'  are called by the completion code.  The shell
	    functions of this set, which implement completion behaviour and  may
	    be bound to keystrokes, are referred to as `widgets'.  These prolif-
	    erate as new completions are required.

INITIALIZATION
     If  the  system  was  installed completely, it should be enough to call the
     shell function compinit from your initialization file; see  the  next  sec-
     tion.   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 re-
     run compinstall and it will correctly locate and modify these lines.  Note,
     however, that any code you add to this section by hand is likely to be lost
     if you rerun compinstall, although lines using the command `zstyle'  should
     be gracefully handled.

     The  new code will take effect next time you start the shell, or run .zshrc
     by hand; there is also an option to  make	them  take  effect  immediately.
     However,  if  compinstall has removed definitions, you will need to restart
     the shell to see the changes.

     To run compinstall you will need to make sure it is  in  a  directory  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 appro-
     priate directories from fpath.  Then it must be  autoloaded  (`autoload  -U
     compinstall'  is recommended).  You can abort the installation any time you
     are being prompted for information, and your .zshrc will not be altered  at
     all;  changes  only take place right at the end, where you are specifically
     asked for confirmation.

   Use of compinit
     This section describes the use of compinit to initialize completion for the
     current session when called directly; if you have run compinstall	it  will
     be called automatically from your .zshrc.

     To  initialize  the  system, the function compinit should be in a directory
     mentioned in the fpath parameter, and should be  autoloaded  (`autoload  -U
     compinit'	is  recommended),  and then run simply as `compinit'.  This will
     define a few utility functions, arrange for all the necessary  shell  func-
     tions to be autoloaded, and will then re-define all widgets that do comple-
     tion  to  use  the new system.  If you use the menu-select widget, which is
     part of the zsh/complist module, you should make sure that that  module  is
     loaded  before the call to compinit so that that widget is also re-defined.
     If completion styles (see below) are set up to perform expansion as well as
     completion by default, and the TAB  key  is  bound  to  expand-or-complete,
     compinit will rebind it to complete-word; this is necessary to use the cor-
     rect form of expansion.

     Should you need to use the original completion commands, you can still bind
     keys  to the old widgets by putting a `.' in front of the widget name, e.g.
     `.expand-or-complete'.

     To speed up the running of compinit, it can be made  to  produce  a  dumped
     configuration  that  will be read in on future invocations; this is the de-
     fault, but can be turned off by calling compinit with the option  -D.   The
     dumped  file is .zcompdump in the same directory as the startup files (i.e.
     $ZDOTDIR or $HOME); alternatively, an explicit file name can  be  given  by
     `compinit	-d  dumpfile'.	 The  next  invocation of compinit will read the
     dumped file instead of performing a full initialization.

     If the number of completion files changes, compinit will recognise this and
     produce a new dump file.  However, if the name of a function or  the  argu-
     ments 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-cre-
     ate  it  the  next time it is run.  The check performed to see if there are
     new functions can be omitted by giving the option -C.   In  this  case  the
     dump  file  will only be created if there isn't one already.  Use option -w
     to explain why a dump file isn't loaded and/or why it's regenerated.

     The dumping is actually done by another function, compdump,  but  you  will
     only  need to run this yourself if you change the configuration (e.g. using
     compdef) and then want to dump the new one.  The name  of	the  old  dumped
     file will be remembered for this purpose.

     If  the  parameter  _compdir  is set, compinit uses it as a directory where
     completion functions can be found; this is only necessary if they	are  not
     already in the function search path.

     For  security  reasons  compinit also checks if the completion system would
     use files not owned by root or by the current user, or files in directories
     that are world- or group-writable or that are not owned by root or  by  the
     current user.  If such files or directories are found, compinit will ask if
     the completion system should really be used.  To avoid these tests and make
     all  files  found	be  used  without asking, use the option -u, and to make
     compinit silently ignore all insecure files and directories use the  option
     -i.   This  security check is skipped entirely when the -C option is given,
     provided the dumpfile exists.

     The security check can be retried at any time by running the function  com-
     paudit.   This  is the same check used by compinit, but when it is executed
     directly any changes to fpath are made local to the function so they do not
     persist.  The directories to be checked may be passed as arguments; if none
     are given, compaudit uses fpath and _compdir to find completion system  di-
     rectories,  adding missing ones to fpath as necessary.  To force a check of
     exactly the directories currently named in fpath, set _compdir to an  empty
     string before calling compaudit or compinit.

     The  function  bashcompinit provides compatibility with bash's programmable
     completion system.  When run it will define the functions, compgen and com-
     plete which correspond to the bash builtins with the same names.	It  will
     then be possible to use completion specifications and functions written for
     bash.

   Autoloaded files
     The  convention  for  autoloaded  functions used in completion is that they
     start with an underscore; as already mentioned, the  fpath/FPATH  parameter
     must  contain  the directory in which they are stored.  If zsh was properly
     installed on your system, then fpath/FPATH automatically contains	the  re-
     quired directories for the standard functions.

     For incomplete installations, if compinit does not find enough files begin-
     ning with an underscore (fewer than twenty) in the search path, it will try
     to  find more by adding the directory _compdir to the search path.  If that
     directory has a subdirectory named Base, all subdirectories will  be  added
     to  the  path.   Furthermore,  if	the subdirectory Base has a subdirectory
     named Core, compinit will add all subdirectories of the  subdirectories  to
     the  path: this allows the functions to be in the same format as in the zsh
     source distribution.

     When compinit is run, it searches all such files accessible via fpath/FPATH
     and reads the first line of each of them.	This line should contain one  of
     the  tags	described below.  Files whose first line does not start with one
     of these tags are not considered to be part of the  completion  system  and
     will not be treated specially.

     The tags are:

     #compdef name ... [ -{p|P} pattern ... [ -N name ... ] ]
	    The  file  will  be made autoloadable and the function defined in it
	    will be called when completing names, each of which  is  either  the
	    name  of  a  command whose arguments are to be completed or one of a
	    number of special contexts in the form -context- described below.

	    Each name may also be of the form  `cmd=service'.	When  completing
	    the  command  cmd,	the function typically behaves as if the command
	    (or special context) service was being completed instead.  This pro-
	    vides a way of altering the behaviour of functions that can  perform
	    many  different completions.  It is implemented by setting the para-
	    meter $service when calling the function; the function may choose to
	    interpret this how it wishes, and simpler  functions  will	probably
	    ignore it.

	    If the #compdef line contains one of the options -p or -P, the words
	    following  are  taken  to  be patterns.  The function will be called
	    when completion is attempted for a command or context  that  matches
	    one of the patterns.  The options -p and -P are used to specify pat-
	    terns  to  be  tried before or after other completions respectively.
	    Hence -P may be used to specify default actions.

	    The option -N is used after a list following -p or -P; it  specifies
	    that  remaining  words no longer define patterns.  It is possible to
	    toggle between the three options as many times as necessary.

     #compdef -k style key-sequence ...
	    This option creates a widget behaving like the builtin widget  style
	    and  binds it to the given key-sequences, if any.  The style must be
	    one of the builtin widgets	that  perform  completion,  namely  com-
	    plete-word,  delete-char-or-list, expand-or-complete, expand-or-com-
	    plete-prefix, list-choices, menu-complete,	menu-expand-or-complete,
	    or reverse-menu-complete.  If the zsh/complist module is loaded (see
	    zshmodules(1)) the widget menu-select is also available.

	    When  one  of  the	key-sequences is typed, the function in the file
	    will be invoked to generate the matches.  Note that a key  will  not
	    be re-bound if 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-sequence [ name style seq ... ]
	    This is similar to -k except that only one key-sequence argument may
	    be given for each widget-name style pair.  However, the  entire  set
	    of	three  arguments  may  be repeated with a different set of argu-
	    ments.  Note in particular that the widget-name must be distinct  in
	    each  set.	 If  it does not begin with `_' this will be added.  The
	    widget-name should not clash with the name of any  existing  widget:
	    names  based on the name of the function are most useful.  For exam-
	    ple,

		   #compdef -K _foo_complete complete-word "^X^C" \
		     _foo_list list-choices "^X^D"

	    (all on one line) defines a  widget  _foo_complete	for  completion,
	    bound  to  `^X^C',	and  a	widget	_foo_list  for listing, bound to
	    `^X^D'.

     #autoload [ options ]
	    Functions with the #autoload tag are marked for autoloading but  are
	    not  otherwise  treated  specially.  Typically they are to be called
	    from within one of the completion functions.  Any  options	supplied
	    will be passed to the autoload builtin; a typical use is +X to force
	    the  function  to  be  loaded  immediately.  Note that the -U and -z
	    flags are always added implicitly.

     The # is part of the tag name and no white space is allowed after it.   The
     #compdef tags use the compdef function described below; the main difference
     is that the name of the function is supplied implicitly.

     The special contexts for which completion functions can be defined are:

     -array-value-
	    The right hand side of an array-assignment (`name=(...)')

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

     -brace-parameter-
	    The name of a parameter expansion within braces (`${...}')

     -command-
	    A word in command position

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

     -default-
	    Any word for which no other completion is defined

     -equal-
	    A word beginning with an equals sign

     -first-
	    This  is  tried  before any other completion function.  The function
	    called may set the _compskip parameter to  one  of	various  values:
	    all:  no  further  completion  is attempted; a string containing the
	    substring patterns: no pattern completion functions will be  called;
	    a  string  containing default: the function for the `-default-' con-
	    text will not be called, but functions defined for commands will be.

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

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

     -redirect-
	    The word after a redirection operator.

     -subscript-
	    The contents of a parameter subscript.

     -tilde-
	    After an initial tilde (`~'), but before  the  first  slash  in  the
	    word.

     -value-
	    On the right hand side of an assignment.

     Default  implementations  are supplied for each of these contexts.  In most
     cases the context -context- is  implemented  by  a  corresponding	function
     _context, for example the context `-tilde-' and the function `_tilde').

     The  contexts  -redirect- and -value- allow extra context-specific informa-
     tion.  (Internally, this is handled by the functions for each context call-
     ing the function _dispatch.)  The extra information is added  separated  by
     commas.

     For  the  -redirect-  context, the extra information is in the form `-redi-
     rect-,op,command', where op is the redirection operator and command is  the
     name  of  the command on the line.  If there is no command on the line yet,
     the command field will be empty.

     For the -value- context, the form is `-value-,name,command', where name  is
     the  name of the parameter on the left hand side of the assignment.  In the
     case of elements of an associative array, for example  `assoc=(key  <TAB>',
     name  is expanded to `name-key'.  In certain special contexts, such as com-
     pleting after `make CFLAGS=', the command part gives the name of  the  com-
     mand, here make; otherwise it is empty.

     It  is  not necessary to define fully specific completions as the functions
     provided will try to generate completions by  progressively  replacing  the
     elements with `-default-'.  For example, when completing after `foo=<TAB>',
     _value  will  try	the  names `-value-,foo,' (note the empty command part),
     `-value-,foo,-default-' and`-value-,-default-,-default-',	in  that  order,
     until it finds a function to handle the context.

     As an example:

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

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

     Also:

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

     specifies that _foo provides completions for the values of  parameters  for
     which no special function has been defined.  This is usually handled by the
     function _value itself.

     The same lookup rules are used when looking up styles (as described below);
     for example

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

     is  another way to make completion after `2> <TAB>' complete files matching
     `*.log'.

   Functions
     The following function is defined by compinit and may be called directly.

     compdef [ -ane ] function name ... [ -{p|P} pattern ... [ -N name ...]]
     compdef -d name ...
     compdef -k [ -an ] function style key-sequence [ key-sequence ... ]
     compdef -K [ -an ] function name style key-seq [ name style seq ... ]
	    The first form defines the function to call for  completion  in  the
	    given contexts as described for the #compdef tag above.

	    Alternatively,  all  the  arguments may have the form `cmd=service'.
	    Here service should already  have  been  defined  by  `cmd1=service'
	    lines  in  #compdef files, as described above.  The argument for cmd
	    will be completed in the same way as service.

	    The function argument may alternatively be a string  containing  al-
	    most  any  shell  code.   If  the string contains an equal sign, the
	    above will take precedence.  The option -e may be  used  to  specify
	    the  first argument is to be evaluated as shell code even if it con-
	    tains an equal sign.  The string will be  executed	using  the  eval
	    builtin  command  to  generate  completions.  This provides a way of
	    avoiding having to define a new completion function.   For	example,
	    to complete files ending in `.h' as arguments to the command foo:

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

	    The  option -n prevents any completions already defined for the com-
	    mand or context from being overwritten.

	    The option -d deletes any completion defined for the command or con-
	    texts listed.

	    The names may also contain -p, -P and -N options  as  described  for
	    the  #compdef  tag.   The  effect on the argument list is identical,
	    switching between definitions of patterns tried initially,	patterns
	    tried finally, and normal commands and contexts.

	    The  parameter  $_compskip	may be set by any function defined for a
	    pattern context.  If it is set to a value containing  the  substring
	    `patterns'	none  of  the pattern-functions will be called; if it is
	    set to a value containing the substring  `all',  no  other	function
	    will  be called.  Setting $_compskip in this manner is of particular
	    utility when using the -p option, as otherwise the	dispatcher  will
	    move on to additional functions (likely the default one) after call-
	    ing the pattern-context one, which can mangle the display of comple-
	    tion possibilities if not handled properly.

	    The form with -k defines a widget with the same name as the function
	    that  will be called for each of the key-sequences; this is like the
	    #compdef -k tag.   The  function  should  generate	the  completions
	    needed  and will otherwise behave like the builtin widget whose name
	    is given as the style argument.  The widgets usable  for  this  are:
	    complete-word,    delete-char-or-list,    expand-or-complete,    ex-
	    pand-or-complete-prefix,   list-choices,   menu-complete,	menu-ex-
	    pand-or-complete,  and reverse-menu-complete, as well as menu-select
	    if the zsh/complist module is loaded.  The option  -n  prevents  the
	    key  being	bound  if it is already to bound to something other than
	    undefined-key.

	    The form with -K is similar and defines multiple  widgets  based  on
	    the same function, each of which requires the set of three arguments
	    name, style and key-sequence, where the latter two are as for -k and
	    the first must be a unique widget name beginning with an underscore.

	    Wherever  applicable, the -a option makes the function autoloadable,
	    equivalent to autoload -U function.

     The function compdef can be used to associate existing completion functions
     with new commands.  For example,

	    compdef _pids foo

     uses the function _pids to complete process IDs for the command foo.

     Note also the _gnu_generic function described below, which can be	used  to
     complete options for commands that understand the `--help' option.

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 gener-
     ated.

   Overview
     When  completion  is attempted somewhere on the command line the completion
     system begins building the context.  The context represents everything that
     the shell knows about the meaning of the command line and the  significance
     of the cursor position.  This takes account of a number of things including
     the command word (such as `grep' or `zsh') and options to which the current
     word may be an argument (such as the `-o' option to zsh which takes a shell
     option as an argument).

     The  context  starts out very generic ("we are beginning a completion") and
     becomes more specific as more is learned ("the current word is in	a  posi-
     tion  that is usually a command name" or "the current word might be a vari-
     able name" and so on).  Therefore the context will  vary  during  the  same
     call to the completion system.

     This  context information is condensed into a string consisting of multiple
     fields separated by colons, referred to simply as `the context' in the  re-
     mainder  of  the  documentation.  Note that a user of the completion system
     rarely needs to compose a context string, unless for example a new function
     is being written to perform completion for a new command.	What a user  may
     need  to  do is compose a style pattern, which is matched against a context
     when needed to look up context-sensitive options that configure the comple-
     tion system.

     The next few paragraphs explain how a context is composed within  the  com-
     pletion function suite.  Following that is discussion of how styles are de-
     fined.  Styles determine such things as how the matches are generated, sim-
     ilarly  to shell options but with much more control.  They are defined with
     the zstyle builtin command (see zshmodules(1)).

     The context string always consists of a fixed set of fields,  separated  by
     colons and with a leading colon before the first.	Fields which are not yet
     known are left empty, but the surrounding colons appear anyway.  The fields
     are   always   in	the  order  :completion:function:completer:command:argu-
     ment:tag.	These have the following meaning:

     *	    The literal string completion, saying that this style is used by the
	    completion system.	This distinguishes the context from  those  used
	    by, for example, zle widgets and ZFTP functions.

     *	    The  function,  if	completion  is called from a named widget rather
	    than through the normal completion system.	Typically this is blank,
	    but it is set by special widgets such as predict-on and the  various
	    functions in the Widget directory of the distribution to the name of
	    that function, often in an abbreviated form.

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

     *	    The command or a special -context-, just at it appears following the
	    #compdef tag or the compdef function.  Completion functions for com-
	    mands that have sub-commands usually modify this  field  to  contain
	    the  name  of  the command followed by a minus sign and the sub-com-
	    mand.  For example, the completion function for the cvs command sets
	    this field to cvs-add when completing arguments to the  add  subcom-
	    mand.

     *	    The  argument;  this indicates which command line or option argument
	    we are completing.	For command arguments this generally  takes  the
	    form  argument-n, where n is the number of the argument, and for ar-
	    guments to options the form option-opt-n where n is  the  number  of
	    the  argument  to option opt.  However, this is only the case if the
	    command line is parsed with standard UNIX-style  options  and  argu-
	    ments, so many completions do not set this.

     *	    The tag.  As described previously, tags are used to discriminate be-
	    tween  the	types of matches a completion function can generate in a
	    certain context.  Any completion function may use any  tag	name  it
	    likes, but a list of the more common ones is given below.

     The context is gradually put together as the functions are executed, start-
     ing with the main entry point, which adds :completion: and the function el-
     ement  if	necessary.   The completer then adds the completer element.  The
     contextual completion adds the command and argument options.  Finally,  the
     tag is added when the types of completion are known.  For example, the con-
     text name

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

     says  that normal completion was attempted as the first argument to the op-
     tion -o of the command dvips:

	    dvips -o ...

     and the completion function will generate filenames.

     Usually completion will be tried for all possible tags in an order given by
     the completion function.  However, this can be altered by using the tag-or-
     der style.  Completion is then restricted to the list of given tags in  the
     given order.

     The  _complete_help bindable command shows all the contexts and tags avail-
     able for completion at a particular point.  This provides an  easy  way  of
     finding information for tag-order and other styles.  It is described in the
     section `Bindable Commands' below.

     When  looking  up styles the completion system uses full context names, in-
     cluding the tag.  Looking up the value of a style therefore consists of two
     things: the context, which is matched to the most specific  (best	fitting)
     pattern,  and  the name of the style itself, which must be matched exactly.
     The following examples demonstrate that patterns may be loosely defined for
     styles that apply broadly, or as tightly defined as desired for styles that
     apply in narrower circumstances.

     For example, many completion functions can generate matches in a simple and
     a verbose form and use the verbose style to decide  which	form  should  be
     used.  To make all such functions use the verbose form, put

	    zstyle ':completion:*' verbose yes

     in  a  startup  file  (probably  .zshrc).	This gives the verbose style the
     value yes in every context inside the completion system, unless  that  con-
     text  has	a more specific definition.  It is best to avoid giving the pat-
     tern as `*' in case the style has some meaning outside the completion  sys-
     tem.

     Many  such  general  purpose  styles  can be configured simply by using the
     compinstall function.

     A more specific example of the use of the verbose style is by  the  comple-
     tion for the kill builtin.  If the style is set, the builtin lists full job
     texts  and  process  command lines; otherwise it shows the bare job numbers
     and PIDs.	To turn the style off for this use only:

	    zstyle ':completion:*:*:kill:*:*' verbose no

     For even more control, the  style	can  use  one  of  the	tags  `jobs'  or
     `processes'.  To turn off verbose display only for jobs:

	    zstyle ':completion:*:*:kill:*:jobs' verbose no

     The  -e  option to zstyle even allows completion function code to appear as
     the argument to a style; this requires some understanding of the  internals
     of completion functions (see see zshcompwid(1))).	For example,

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

     This  forces  the value of the hosts style to be read from the variable my-
     hosts each time a host name is needed; this is useful if the value  of  my-
     hosts  can change dynamically.  For another useful example, see the example
     in the description of the file-list style below.  This form can be slow and
     should  be  avoided  for  commonly  examined  styles  such  as   menu   and
     list-rows-first.

     Note  that the order in which styles are defined does not matter; the style
     mechanism uses the most specific possible match for a particular  style  to
     determine	the set of values.  Strings are preferred over patterns (for ex-
     ample,  `:completion::complete:::foo'  is	more  specific	than   `:comple-
     tion::complete:::*'),  and  longer  patterns are preferred over the pattern
     `*'. See zmodules(1) for details.

     Context patterns that use something other than a wildcard (*) to match  the
     middle  parts  of	the  context  -- the completer, command, and argument in
     :completion:function:completer:command:argument:tag -- should  include  all
     six  colons  (:)  explicitly.  Without  this,  a  pattern	such as :comple-
     tion:*:foo:* could match foo against a component other  than  the	intended
     one  (for	example,  against completer when a match against command was in-
     tended).

     Style names like those of tags are arbitrary and depend on  the  completion
     function.	However, the following two sections list some of the most common
     tags and styles.

   Standard Tags
     Some  of  the following are only used when looking up particular styles and
     do not refer to a type of match.

     accounts
	    used to look up the users-hosts style

     all-expansions
	    used by the _expand completer when adding the single string contain-
	    ing all possible expansions

     all-files
	    for the names of all files (as distinct from  a  particular  subset,
	    see the globbed-files tag).

     arguments
	    for arguments to a command

     arrays
	    for names of array parameters

     association-keys
	    for  keys  of associative arrays; used when completing inside a sub-
	    script to a parameter of this type

     bookmarks
	    when completing bookmarks (e.g.  for  URLs	and  the  zftp	function
	    suite)

     builtins
	    for names of builtin commands

     characters
	    for  single characters in arguments of commands such as stty.   Also
	    used when completing character classes after an opening bracket

     colormapids
	    for X colormap ids

     colors
	    for color names

     commands
	    for names of external commands.  Also used by complex commands  such
	    as cvs when completing names subcommands.

     contexts
	    for contexts in arguments to the zstyle builtin command

     corrections
	    used  by  the _approximate and _correct completers for possible cor-
	    rections

     cursors
	    for cursor names used by X programs

     default
	    used in some contexts to provide a way of supplying a  default  when
	    more  specific tags are also valid.  Note that this tag is used when
	    only the function field of the context name is set

     descriptions
	    used when looking up the value of the format style to  generate  de-
	    scriptions for types of matches

     devices
	    for names of device special files

     directories
	    for  names	of directories -- local-directories is used instead when
	    completing arguments of cd and related builtin commands when the cd-
	    path array is set

     directory-stack
	    for entries in the directory stack

     displays
	    for X display names

     domains
	    for network domains

     email-plugin
	    for email addresses from the `_email-plugin' backend  of  _email_ad-
	    dresses

     expansions
	    used  by  the  _expand completer for individual words (as opposed to
	    the complete set of expansions) resulting from the	expansion  of  a
	    word on the command line

     extensions
	    for X server extensions

     file-descriptors
	    for numbers of open file descriptors

     files  the generic file-matching tag used by functions completing filenames

     fonts  for X font names

     fstypes
	    for file system types (e.g. for the mount command)

     functions
	    names  of  functions  --  normally shell functions, although certain
	    commands may understand other kinds of function

     globbed-files
	    for filenames when the name has been generated by pattern matching

     groups
	    for names of user groups

     history-words
	    for words from the history

     hosts  for hostnames

     indexes
	    for array indexes

     interfaces
	    for network interfaces

     jobs   for jobs (as listed by the `jobs' builtin)

     keymaps
	    for names of zsh keymaps

     keysyms
	    for names of X keysyms

     libraries
	    for names of system libraries

     limits
	    for system limits

     local-directories
	    for names of directories that  are	subdirectories	of  the  current
	    working  directory	when  completing  arguments  of  cd  and related
	    builtin commands (compare path-directories) -- when the cdpath array
	    is unset, directories is used instead

     mailboxes
	    for e-mail folders

     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

     newsgroups
	    for USENET groups

     nicknames
	    for nicknames of NIS maps

     options
	    for command options

     original
	    used by the _approximate, _correct and _expand completers  when  of-
	    fering the original string as a match

     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 arguments of cd and related builtin commands (compare lo-
	    cal-directories)

     paths  used to look up the values of the expand, ambiguous and special-dirs
	    styles

     pods   for perl pods (documentation files)

     ports  for communication ports

     prefixes
	    for prefixes (like those of a URL)

     printers
	    for print queue names

     processes
	    for process identifiers

     processes-names
	    used to look up the command  style	when  generating  the  names  of
	    processes for killall

     sequences
	    for sequences (e.g. mh sequences)

     sessions
	    for sessions in the zftp function suite

     signals
	    for signal names

     strings
	    for  strings  (e.g.  the replacement strings for the cd builtin com-
	    mand)

     styles
	    for styles used by the zstyle builtin command

     suffixes
	    for filename extensions

     tags   for tags (e.g. rpm tags)

     targets
	    for makefile targets

     time-zones
	    for time zones (e.g. when setting the TZ parameter)

     types  for types of whatever (e.g. address types for the xhost command)

     urls   used to look up the urls and local styles when completing URLs

     users  for usernames

     values
	    for one of a set of values in certain lists

     variant
	    used by _pick_variant to look up the command to run when determining
	    what program is installed for a particular command name.

     visuals
	    for X visuals

     warnings
	    used to look up the format style for warnings

     widgets
	    for zsh widget names

     windows
	    for IDs of X windows

     zsh-options
	    for shell options

   Standard Styles
     Note that the values of several of these styles represent	boolean  values.
     Any  of  the strings `true', `on', `yes', and `1' can be used for the value
     `true' and any of the strings `false', `off', `no', and `0' for  the  value
     `false'.	The  behavior  for any other value is undefined except where ex-
     plicitly mentioned.  The default value may be either `true' or  `false'  if
     the style is not set.

     Some  of these styles are tested first for every possible tag corresponding
     to a type of match, and if no style was found, for the  default  tag.   The
     most  notable styles of this type are menu, list-colors and styles control-
     ling completion listing such as list-packed and last-prompt.   When  tested
     for  the default tag, only the function field of the context will be set so
     that a style using the default tag will normally be defined along the lines
     of:

	    zstyle ':completion:*:default' menu ...

     accept-exact
	    This is tested for the default tag in addition to the tags valid for
	    the current context.  If it is set to `true' and any  of  the  trial
	    matches  is  the  same as the string on the command line, this match
	    will immediately be accepted (even if it would otherwise be  consid-
	    ered ambiguous).

	    When completing pathnames (where the tag used is `paths') this style
	    accepts  any  number  of  patterns	as  the value in addition to the
	    boolean values.  Pathnames matching one of these  patterns	will  be
	    accepted  immediately  even  if  the command line contains some more
	    partially typed pathname components and these match  no  file  under
	    the directory accepted.

	    This  style is also used by the _expand completer to decide if words
	    beginning with a tilde or parameter expansion  should  be  expanded.
	    For  example,  if  there  are  parameters foo and foobar, the string
	    `$foo' will only be expanded if accept-exact is set to `true';  oth-
	    erwise  the  completion  system  will be allowed to complete $foo to
	    $foobar. If the style is set to `continue', _expand will add the ex-
	    pansion as a match and the completion system will also be allowed to
	    continue.

     accept-exact-dirs
	    This is used by filename completion.  Unlike accept-exact  it  is  a
	    boolean.  By default, filename completion examines all components of
	    a  path  to  see if there are completions of that component, even if
	    the component matches an existing directory.  For example, when com-
	    pletion after /usr/bin/, the function examines possible  completions
	    to /usr.

	    When  this style is `true', any prefix of a path that matches an ex-
	    isting directory is accepted without any attempt to complete it fur-
	    ther.  Hence, in the given example, the path /usr/bin/  is	accepted
	    immediately and completion tried in that directory.

	    This  style  is  also  useful when completing after directories that
	    magically appear when referenced, such as ZFS  .zfs  directories  or
	    NetApp  .snapshot directories.  When the style is set the shell does
	    not check for the existence of the directory within the  parent  di-
	    rectory.

	    If you wish to inhibit this behaviour entirely, set the path-comple-
	    tion style (see below) to `false'.

     add-space
	    This  style  is used by the _expand completer.  If it is `true' (the
	    default), a space will be inserted after all  words  resulting  from
	    the  expansion,  or  a slash in the case of directory names.  If the
	    value is `file', the completer will only add a space to names of ex-
	    isting files.  Either a boolean `true' or the value  `file'  may  be
	    combined  with  `subst',  in which case the completer will not add a
	    space to words generated from the expansion of a substitution of the
	    form `$(...)' or `${...}'.

	    The _prefix completer uses this style as a simple boolean  value  to
	    decide if a space should be inserted before the suffix.

     ambiguous
	    This applies when completing non-final components of filename paths,
	    in	other words those with a trailing slash.  If it is set, the cur-
	    sor is left after the first ambiguous component, even if  menu  com-
	    pletion is in use.	The style is always tested with the paths tag.

     assign-list
	    When completing after an equals sign that is being treated as an as-
	    signment,  the  completion	system normally completes only one file-
	    name.  In some cases the value  may be a list of filenames separated
	    by colons, as with PATH and similar parameters.  This style  can  be
	    set to a list of patterns matching the names of such parameters.

	    The  default  is to complete lists when the word on the line already
	    contains a colon.

     auto-description
	    If set, this style's value will be used as the description	for  op-
	    tions  that  are not described by the completion functions, but that
	    have exactly one argument.	The sequence `%d' in the value	will  be
	    replaced  by  the  description for this argument.  Depending on per-
	    sonal preferences, it may be useful to set this style  to  something
	    like `specify: %d'.  Note that this may not work for some commands.

     avoid-completer
	    This  is  used by the _all_matches completer to decide if the string
	    consisting of all matches should be added to the list currently  be-
	    ing  generated.  Its value is a list of names of completers.  If any
	    of these is the name of the completer that generated the matches  in
	    this completion, the string will not be added.

	    The  default value for this style is `_expand _oldlist _correct _ap-
	    proximate', i.e. it contains the completers for which a string  with
	    all matches will almost never be wanted.

     cache-path
	    This  style defines the path where any cache files containing dumped
	    completion data are stored.  It defaults to  `$ZDOTDIR/.zcompcache',
	    or	`$HOME/.zcompcache'  if $ZDOTDIR is not defined.  The completion
	    cache will not be used unless the use-cache style is set.

     cache-policy
	    This style defines the function  that  will  be  used  to  determine
	    whether a cache needs rebuilding.  See the section on the _cache_in-
	    valid function below.

     call-command
	    This style is used in the function for commands such as make and ant
	    where calling the command directly to generate matches suffers prob-
	    lems  such	as being slow or, as in the case of make can potentially
	    cause actions in the makefile to be executed. If it is set to `true'
	    the command is called to generate matches. The default value of this
	    style is `false'.

     command
	    In many places, completion functions need to call external	commands
	    to	generate  the  list  of  completions.  This style can be used to
	    override the command that is called in some such  cases.   The  ele-
	    ments  of the value are joined with spaces to form a command line to
	    execute.  The value can also start with a hyphen, in which case  the
	    usual  command  will  be  added  to the end; this is most useful for
	    putting `builtin' or `command' in front to make sure the appropriate
	    version of a command is called, for example to avoid calling a shell
	    function with the same name as an external command.

	    As an example, the completion function for	process  IDs  uses  this
	    style with the processes tag to generate the IDs to complete and the
	    list  of processes to display (if the verbose style is `true').  The
	    list produced by the command should look like the output of  the  ps
	    command.   The  first line is not displayed, but is searched for the
	    string `PID' (or `pid') to find the position of the process  IDs  in
	    the  following lines.  If the line does not contain `PID', the first
	    numbers in each of the other lines are taken as the process  IDs  to
	    complete.

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

     command-path
	    This  is  a  list of directories to search for commands to complete.
	    The default for this style is the value  of  the  special  parameter
	    path.

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

     complete
	    This is used by the _expand_alias function when invoked as	a  bind-
	    able  command.  If set to `true' and the word on the command line is
	    not the name of an alias, matching alias names will be completed.

     complete-options
	    This is used by the completer for cd, chdir and  pushd.   For  these
	    commands  a  - is used to introduce a directory stack entry and com-
	    pletion of these is far more common than completing options.   Hence
	    unless  the  value	of this style is `true' options will not be com-
	    pleted, even after an initial -.  If it is `true', options	will  be
	    completed  after  an initial - unless there is a preceding -- on the
	    command line.

     completer
	    The strings given as the value of this style provide  the  names  of
	    the  completer  functions  to use. The available completer functions
	    are described in the section `Control Functions' below.

	    Each string may be either the name of  a  completer  function  or  a
	    string of the form `function:name'.  In the first case the completer
	    field  of the context will contain the name of the completer without
	    the leading underscore and with all other  underscores  replaced  by
	    hyphens.   In  the	second case the function is the name of the com-
	    pleter to call, but the context will contain the  user-defined  name
	    in	the  completer	field of the context.  If the name starts with a
	    hyphen, the string for the context will be build from  the	name  of
	    the  completer  function as in the first case with the name appended
	    to it.  For example:

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

	    Here, completion will call the _complete completer twice, once using
	    `complete' and once using `complete-foo' in the completer  field  of
	    the context.  Normally, using the same completer more than once only
	    makes sense when used with the `functions:name' form, because other-
	    wise  the  context	name  will  be the same in all calls to the com-
	    pleter; possible exceptions to this rule are the _ignored and  _pre-
	    fix completers.

	    The  default value for this style is `_complete _ignored': only com-
	    pletion will be done, first using the ignored-patterns style and the
	    $fignore array and then without ignoring matches.

     condition
	    This style is used by the _list completer function to decide if  in-
	    sertion of matches should be delayed unconditionally. The default is
	    `true'.

     delimiters
	    This style is used when adding a delimiter for use with history mod-
	    ifiers  or	glob qualifiers that have delimited arguments.	It is an
	    array of preferred delimiters to add.   Non-special  characters  are
	    preferred  as  the	completion system may otherwise become confused.
	    The default list is :, +, /, -, %.	The list may be empty to force a
	    delimiter to be typed.

     disabled
	    If this is set to `true', the _expand_alias completer  and	bindable
	    command  will  try	to expand disabled aliases, too.  The default is
	    `false'.

     domains
	    A list of names of network domains for completion.	If this  is  not
	    set, domain names will be taken from the file /etc/resolv.conf.

     environ
	    The  environ style is used when completing for `sudo'.  It is set to
	    an array of `VAR=value' assignments to be exported	into  the  local
	    environment before the completion for the target command is invoked.
	    zstyle ':completion:*:sudo::' environ \
	      PATH="/sbin:/usr/sbin:$PATH" HOME="/root"

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

	    If one of its values is the string	`prefix',  the	partially  typed
	    word  from	the  line  will  be  expanded as far as possible even if
	    trailing parts cannot be completed.

	    If one of its values is the string `suffix', matching names for com-
	    ponents after the first ambiguous one  will  also  be  added.   This
	    means  that  the  resulting string is the longest unambiguous string
	    possible.  However, menu completion can be used to cycle through all
	    matches.

     extra-verbose
	    If this style set to `true', the completion listing  is  still  more
	    verbose.

	    Currently,	it  is	used for commands and parameters tags.	If it is
	    `true' for the commands (or parameters) tag, short	descriptions  of
	    the  commands  (or the values of the parameters) are displayed along
	    with the command (or parameter) names.

     fake   This style may be set for any completion context.  It specifies  ad-
	    ditional strings that will always be completed in that context.  The
	    form  of  each string is `value:description'; the colon and descrip-
	    tion may be omitted, but any literal colons in value must be  quoted
	    with  a  backslash.  Any description provided is shown alongside the
	    value in completion listings.

	    It is important to use a sufficiently restrictive context when spec-
	    ifying fake strings.  Note that the styles fake-files and fake-para-
	    meters provide additional features when completing files or  parame-
	    ters.

     fake-always
	    This  works  identically  to  the  fake  style  except  that the ig-
	    nored-patterns style is not applied to it.	This makes  it	possible
	    to	override a set of matches completely by setting the ignored pat-
	    terns to `*'.

	    The following shows a way of supplementing any  tag  with  arbitrary
	    data, but having it behave for display purposes like a separate tag.
	    In this example we use the features of the tag-order style to divide
	    the  named-directories  tag into two when performing completion with
	    the standard completer  complete  for  arguments  of  cd.	The  tag
	    named-directories-normal behaves as normal, but the tag named-direc-
	    tories-mine  contains  a fixed set of directories.	This has the ef-
	    fect of adding the match group `extra directories'	with  the  given
	    completions.

		   zstyle ':completion::complete:cd:*' tag-order \
		     'named-directories:-mine:extra\ directories
		     named-directories:-normal:named\ directories *'
		   zstyle ':completion::complete:cd:*:named-directories-mine' \
		     fake-always mydir1 mydir2
		   zstyle ':completion::complete:cd:*:named-directories-mine' \
		     ignored-patterns '*'

     fake-files
	    This  style  is  used  when completing files and looked up without a
	    tag.  Its values are of the form `dir:names...'.  This will add  the
	    names  (strings  separated	by spaces) as possible matches when com-
	    pleting in the directory dir, even if no such  files  really  exist.
	    The dir may be a pattern; pattern characters or colons in dir should
	    be quoted with a backslash to be treated literally.

	    This  can  be  useful  on  systems that support special file systems
	    whose top-level pathnames can not be listed or generated  with  glob
	    patterns  (but see accept-exact-dirs for a more general way of deal-
	    ing with this problem).  It can also be  used  for	directories  for
	    which one does not have read permission.

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

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

     file-list
	    This style controls  whether  files  completed  using  the	standard
	    builtin  mechanism	are  to be listed with a long list similar to ls
	    -l.  Note that this feature uses the shell module zsh/stat for  file
	    information;  this loads the builtin stat which will replace any ex-
	    ternal stat executable.  To avoid this the following code can be in-
	    cluded in an initialization file:

		   zmodload -i zsh/stat
		   disable stat

	    The style may either be set to a `true' value (or `all'), or one  of
	    the  values  `insert'  or  `list',	indicating  that files are to be
	    listed in long format in all circumstances, or  when  attempting  to
	    insert a file name, or when listing file names without attempting to
	    insert one.

	    More  generally,  the value may be an array of any of the above val-
	    ues, optionally followed by =num.  If num is present  it  gives  the
	    maximum number of matches for which long listing style will be used.
	    For example,

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

	    specifies  that long format will be used when listing up to 20 files
	    or inserting a file with up to 10 matches (assuming a listing is  to
	    be shown at all, for example on an ambiguous completion), else short
	    format will be used.

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

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

     file-patterns
	    This is used by the  standard  function  for  completing  filenames,
	    _files.   If  the  style  is  unset  up  to  three tags are offered,
	    `globbed-files',`directories'  and	`all-files',  depending  on  the
	    types  of  files   expected  by the caller of _files.  The first two
	    (`globbed-files' and `directories') are normally offered together to
	    make it easier to complete files in sub-directories.

	    The file-patterns style provides alternatives to the  default  tags,
	    which  are	not  used.   Its  value consists of elements of the form
	    `pattern:tag'; each string may contain any number of such specifica-
	    tions separated by spaces.

	    The pattern is a pattern that is to be used to  generate  filenames.
	    Any  occurrence  of  the sequence `%p' is replaced by any pattern(s)
	    passed by the function calling _files.  Colons in the  pattern  must
	    be	preceded  by  a  backslash to make them distinguishable from the
	    colon before the tag.  If more than one pattern is needed, the  pat-
	    terns can be given inside braces, separated by commas.

	    The  tags  of all strings in the value will be offered by _files and
	    used when looking up other styles.	Any tags in the same  word  will
	    be offered at the same time and before later words.  If no `:tag' is
	    given the `files' tag will be used.

	    The  tag  may also be followed by an optional second colon and a de-
	    scription, which will be used for the `%d' in the value of the  for-
	    mat  style	(if that is set) instead of the default description sup-
	    plied by the completion function.  The inclusion  of  a  description
	    also  gives  precedence to associated options such as for completion
	    grouping so it can be used where files should be separated.

	    For example, to make the rm command first complete only names of ob-
	    ject files and then the names of all files if there is  no	matching
	    object file:

		   zstyle ':completion:*:*:rm:*:*' file-patterns \
		       '*.o:object-files' '%p:all-files'

	    To	alter  the  default  behaviour of file completion -- offer files
	    matching a pattern and directories on the first  attempt,  then  all
	    files -- to offer only matching files on the first attempt, then di-
	    rectories, and finally all files:

		   zstyle ':completion:*' file-patterns \
		       '%p:globbed-files' '*(-/):directories' '*:all-files'

	    This  works  even  where there is no special pattern: _files matches
	    all files using the pattern `*' at the first step and stops when  it
	    sees  this pattern.  Note also it will never try a pattern more than
	    once for a single completion attempt.

	    To separate directories into a separate group  from  the  files  but
	    still  complete them at the first attempt, a description needs to be
	    given.  Note that directories need to be  explicitly  excluded  from
	    the  globbed-files because `*' will match directories. For grouping,
	    it is also necessary to set the group-name style.

		   zstyle ':completion:*' file-patterns \
		       '%p(^-/):globbed-files *(-/):directories:location'

	    During the execution of completion functions, the EXTENDED_GLOB  op-
	    tion  is  in effect, so the characters `#', `~' and `^' have special
	    meanings in the patterns.

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

     file-split-chars
	    A set of characters that will cause all  file  completions	for  the
	    given  context  to be split at the point where any of the characters
	    occurs.  A typical use is to set the style to :; then everything  up
	    to	and  including	the  last : in the string so far is ignored when
	    completing files.  As this is  quite  heavy-handed,  it  is  usually
	    preferable	to  update  completion functions for contexts where this
	    behaviour is useful.

     filter
	    The ldap plugin of email address completion  (see  _email_addresses)
	    uses this style to specify the attributes to match against when fil-
	    tering entries.  So for example, if the style is set to `sn', match-
	    ing  is  done  against surnames.  Standard LDAP filtering is used so
	    normal completion matching is bypassed.  If this style is  not  set,
	    the  LDAP  plugin  is skipped.  You may also need to set the command
	    style to specify how to connect to your LDAP server.

     force-list
	    This forces a list of completions to be shown  at  any  point  where
	    listing  is done, even in cases where the list would usually be sup-
	    pressed.  For example, normally the list is only shown if there  are
	    at	least two different matches.  By setting this style to `always',
	    the list will always be shown, even if there is only a single  match
	    that  will	immediately be accepted.  The style may also be set to a
	    number.  In this case the list will be shown if there are  at  least
	    that many matches, even if they would all insert the same string.

	    This  style  is  tested  for the default tag as well as for each tag
	    valid for the current completion.  Hence the listing can  be  forced
	    only for certain types of match.

     format
	    If	this  is  set  for  the descriptions tag, its value is used as a
	    string to display above matches in completion lists.   The	sequence
	    `%d'  in  this  string  will be replaced with a short description of
	    what these matches are.  This string may also contain the output at-
	    tribute sequences understood by compadd -X (see zshcompwid(1)).

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

	    Note also that some completer functions  define  additional  `%'-se-
	    quences.   These are described for the completer functions that make
	    use of them.

	    Some completion functions display messages that may be customised by
	    setting this style for the messages tag.  Here, the `%d' is replaced
	    with a message given by the completion function.

	    Finally, the format string is looked up with the warnings  tag,  for
	    use  when  no  matches  could be generated at all.	In this case the
	    `%d' is replaced with the descriptions for the matches that were ex-
	    pected separated by spaces.  The sequence `%D' is replaced with  the
	    same descriptions separated by newlines.

	    It	is possible to use printf-style field width specifiers with `%d'
	    and similar escape	sequences.   This  is  handled	by  the  zformat
	    builtin command from the zsh/zutil module, see zshmodules(1).

     gain-privileges
	    If	set to true, this style enables the use of commands like sudo or
	    doas to gain extra privileges when retrieving information  for  com-
	    pletion.  This  is	only done when a command such as sudo appears on
	    the command-line. To force the use of, e.g. sudo or to override  any
	    prefix that might be added due to gain-privileges, the command style
	    can be used with a value that begins with a hyphen.

     glob   This  is used by the _expand completer.  If it is set to `true' (the
	    default), globbing will be attempted on the words resulting  from  a
	    previous  substitution (see the substitute style) or else the origi-
	    nal string from the line.

     global
	    If this is set to `true' (the default), the _expand_alias  completer
	    and bindable command will try to expand global aliases.

     group-name
	    The  completion  system  can group different types of matches, which
	    appear in separate lists.  This style can be used to give the  names
	    of groups for particular tags.  For example, in command position the
	    completion	system generates names of builtin and external commands,
	    names of aliases, shell functions and parameters and reserved  words
	    as	possible  completions.	 To have the external commands and shell
	    functions listed separately:

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

	    As a consequence, any match with the same tag will be  displayed  in
	    the same group.

	    If	the  name  given is the empty string the name of the tag for the
	    matches will be used as the name of the group.  So, to have all dif-
	    ferent 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-.

	    To display the group name in the output, see the format style (q.v.)
	    under the descriptions tag.

     group-order
	    This  style is additional to the group-name style to specify the or-
	    der for display of the groups defined by that style (compare tag-or-
	    der, which determines which completions appear at all).  The  groups
	    named  are	shown  in the given order; any other groups are shown in
	    the order defined by the completion function.

	    For example, to have names of builtin commands, shell functions  and
	    external  commands	appear	in that order when completing in command
	    position:

		   zstyle ':completion:*:*:-command-:*:*' group-order \
			  builtins functions commands

     groups
	    A list of names of UNIX groups.  If this is not set, group names are
	    taken from the YP database or the file `/etc/group'.

     hidden
	    If this is set to `true', matches for the given context will not  be
	    listed, although any description for the matches set with the format
	    style  will  be shown.  If it is set to `all', not even the descrip-
	    tion will be displayed.

	    Note that the matches will still be completed;  they  are  just  not
	    shown  in  the list.  To avoid having matches considered as possible
	    completions at all, the tag-order style can be modified as described
	    below.

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

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

     ignore-line
	    This is tested for each tag valid for the current completion.  If it
	    is set to `true', none of the words that are  already  on  the  line
	    will  be  considered as possible completions.  If it is set to `cur-
	    rent', the word the cursor is on will not be considered as a  possi-
	    ble  completion.   The value `current-shown' is similar but only ap-
	    plies if the list of completions is currently shown on  the  screen.
	    Finally,  if  the style is set to `other', all words on the line ex-
	    cept for the current one will be excluded from the possible  comple-
	    tions.

	    The values `current' and `current-shown' are a bit like the opposite
	    of	the  accept-exact  style:   only strings with missing characters
	    will be completed.

	    Note that you almost certainly don't want to set this to  `true'  or
	    `other'  for a general context such as `:completion:*'.  This is be-
	    cause it would disallow completion of, for example, options multiple
	    times even if the command in question accepts the option  more  than
	    once.

     ignore-parents
	    The  style	is tested without a tag by the function completing path-
	    names in order to determine whether to ignore the names of	directo-
	    ries  already mentioned in the current word, or the name of the cur-
	    rent 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	complet-
		   ing after foo/../, the directory foo will not be considered a
		   valid completion.

	    pwd    The	name  of  the current working directory will not be com-
		   pleted; hence, for example, completion after ../ will not use
		   the name of the current directory.

	    In addition, the value may include one or both of:

	    ..	   Ignore the specified directories only when the  word  on  the
		   line contains the substring `../'.

	    directory
		   Ignore  the specified directories only when names of directo-
		   ries are completed, not when completing names of files.

	    Excluded values act in a  similar  fashion	to  values  of	the  ig-
	    nored-patterns  style,  so	they can be restored to consideration by
	    the _ignored completer.

     ignored-patterns
	    A list of patterns; any trial completion matching one  of  the  pat-
	    terns  will  be excluded from consideration.  The _ignored completer
	    can appear in the list of completers to restore the ignored matches.
	    This is a more configurable version of the shell parameter $fignore.

	    Note that the EXTENDED_GLOB option is set during  the  execution  of
	    completion	functions,  so the characters `#', `~' and `^' have spe-
	    cial meanings in the patterns.

     insert
	    This style is used by the _all_matches completer to  decide  whether
	    to	insert the list of all matches unconditionally instead of adding
	    the list as another match.

     insert-ids
	    When completing process IDs, for example as arguments  to  the  kill
	    and  wait builtins the name of a command may be converted to the ap-
	    propriate process ID.  A problem arises when the process name  typed
	    is	not  unique.   By default (or if this style is set explicitly to
	    `menu') the name will be converted immediately to a set of	possible
	    IDs, and menu completion will be started to cycle through them.

	    If the value of the style is `single', the shell will wait until the
	    user  has  typed enough to make the command unique before converting
	    the name to an ID; attempts at completion will be unsuccessful until
	    that point.  If the value is any other string, menu completion  will
	    be started when the string typed by the user is longer than the com-
	    mon prefix to the corresponding IDs.

     insert-sections
	    This style is used with tags of the form `manuals.X' when completing
	    names  of manual pages. If set and the X in the tag name matches the
	    section number of the page being completed, the  section  number  is
	    inserted along with the page name. For example, given

		   zstyle ':completion:*:manuals.*' insert-sections true

	    man ssh_<TAB> may be completed to man 5 ssh_config.

	    The  value	may  also  be  set  to	one  of  `prepend', or `suffix'.
	    `prepend' behaves the same as `true' as in the above example,  while
	    `suffix' would complete man ssh_<TAB> as man ssh_config.5.

	    This  is especially useful in conjunction with separate-sections, as
	    it ensures that the page requested of man  corresponds  to	the  one
	    displayed  in  the	completion listing when there are multiple pages
	    with the same name (e.g., printf(1) and printf(3)).

	    The default for this style is `false'.

     insert-tab
	    If this is set to `true', the completion system will  insert  a  TAB
	    character  (assuming  that	was used to start completion) instead of
	    performing completion when there is no non-blank  character  to  the
	    left  of  the  cursor.   If it is set to `false', completion will be
	    done even there.

	    The value may  also  contain  the  substrings  `pending'  or  `pend-
	    ing=val'.	In  this  case, the typed character will be inserted in-
	    stead of starting completion when there is unprocessed  input  pend-
	    ing.  If a val is given, completion will not be done if there are at
	    least that many characters of unprocessed input.  This is often use-
	    ful  when pasting characters into a terminal.  Note however, that it
	    relies on the $PENDING special parameter from the zsh/zle module be-
	    ing set properly which is not guaranteed on all platforms.

	    The default value of this style  is  `true'  except  for  completion
	    within vared builtin command where it is `false'.

     insert-unambiguous
	    This  is used by the _match and _approximate completers.  These com-
	    pleters are often used with menu completion since the word typed may
	    bear little resemblance to the final completion.  However,	if  this
	    style is `true', the completer will start menu completion only if it
	    could  find  no  unambiguous  initial string at least as long as the
	    original string typed by the user.

	    In the case of the _approximate completer, the  completer  field  in
	    the  context will already have been set to one of correct-num or ap-
	    proximate-num, where num is the number of errors that were accepted.

	    In the case of the _match completer, the style may also  be  set  to
	    the  string  `pattern'.   Then  the  pattern on the line is left un-
	    changed if it does not match unambiguously.

     keep-prefix
	    This style is used by the _expand completer.  If it is  `true',  the
	    completer  will try to keep a prefix containing a tilde or parameter
	    expansion.	Hence, for example, the string `~/f*' would be	expanded
	    to	`~/foo'  instead  of  `/home/user/foo'.   If the style is set to
	    `changed' (the default), the prefix will only be left  unchanged  if
	    there were other changes between the expanded words and the original
	    word from the command line.  Any other value forces the prefix to be
	    expanded unconditionally.

	    The  behaviour of _expand when this style is `true' is to cause _ex-
	    pand to give up when a single expansion with the restored prefix  is
	    the  same  as  the	original;  hence any remaining completers may be
	    called.

     known-hosts-files
	    This style should contain a list of files to search for  host  names
	    and (if the use-ip style is set) IP addresses in a format compatible
	    with   ssh	 known_hosts  files.   If  it  is  not	set,  the  files
	    /etc/ssh/ssh_known_hosts and ~/.ssh/known_hosts are used.

     last-prompt
	    This is a more flexible form of the ALWAYS_LAST_PROMPT  option.   If
	    it is `true', the completion system will try to return the cursor to
	    the previous command line after displaying a completion list.  It is
	    tested  for  all tags valid for the current completion, then the de-
	    fault tag.	The cursor will be moved back to the  previous	line  if
	    this  style  is `true' for all types of match.  Note that unlike the
	    ALWAYS_LAST_PROMPT option this is independent of the  numeric  argu-
	    ment.

     list   This  style  is used by the _history_complete_word bindable command.
	    If it is set to `true' it has no effect.  If it is	set  to  `false'
	    matches  will  not be listed.  This overrides the setting of the op-
	    tions controlling listing behaviour, in particular	AUTO_LIST.   The
	    context always starts with `:completion:history-words'.

     list-colors
	    If	the zsh/complist module is loaded, this style can be used to set
	    color specifications.   This  mechanism  replaces  the  use  of  the
	    ZLS_COLORS	and ZLS_COLOURS parameters described in the section `The
	    zsh/complist Module' in zshmodules(1), but the syntax is the same.

	    If this style is set for the default tag, the strings in  the  value
	    are  taken	as specifications that are to be used everywhere.  If it
	    is set for other tags, the specifications are used only for  matches
	    of	the  type  described  by  the  tag.   For this to work best, the
	    group-name style must be set to an empty string.

	    In addition to setting styles for specific tags, it is also possible
	    to use group names specified explicitly by the  group-name	tag  to-
	    gether  with  the  `(group)'  syntax  allowed  by the ZLS_COLORS and
	    ZLS_COLOURS parameters and simply using the default tag.

	    It is possible to use any color specifications already  set  up  for
	    the GNU version of the ls command:

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

	    The default colors are the same as for the GNU ls command and can be
	    obtained by setting the style to an empty string (i.e. '').

     list-dirs-first
	    This is used by file completion and corresponds to a particular set-
	    ting of the file-patterns style.  If set, the default directories to
	    be	completed  are	listed separately from and before completion for
	    other files.

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

     list-packed
	    This  is tested for each tag valid in the current context as well as
	    the default tag.  If it is set to `true', the corresponding  matches
	    appear  in listings as if the LIST_PACKED option were set.	If it is
	    set to `false', they are listed normally.

     list-prompt
	    If this style is set for the  default  tag,  completion  lists  that
	    don't  fit on the screen can be scrolled (see the 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 set to the empty  string,  a
	    default prompt will be used.

	    The value may contain the escape sequences: `%l' or `%L', which will
	    be	replaced  by the number of the last line displayed and the total
	    number of lines; `%m' or `%M', the number of the  last  match  shown
	    and  the  total  number of matches; and `%p' and `%P', `Top' when at
	    the beginning of the list, `Bottom' when at the end and the position
	    shown as a percentage of the total length otherwise.  In  each  case
	    the  form  with the uppercase letter will be replaced by a string of
	    fixed width, padded to the	right with spaces, while  the  lowercase
	    form  will	be  replaced  by  a  variable width string.  As in other
	    prompt strings, the escape sequences `%S', `%s', `%B',  `%b',  `%U',
	    `%u'  for  entering and leaving the display modes standout, bold and
	    underline, and `%F', `%f', `%K', `%k' for  changing  the  foreground
	    background	colour, are also available, as is the form `%{...%}' for
	    enclosing escape sequences which display with zero (or, with  a  nu-
	    meric argument, some other) width.

	    After  deleting  this prompt the variable LISTPROMPT should be unset
	    for the removal to take effect.

     list-rows-first
	    This style is tested in the same way as the  list-packed  style  and
	    determines	whether matches are to be listed in a rows-first fashion
	    as if the LIST_ROWS_FIRST option were set.

     list-separator
	    The value of this style is used in completion  listing  to	separate
	    the  string  to complete from a description when possible (e.g. when
	    completing options).  It defaults to `--' (two hyphens).

     list-suffixes
	    This style is used by the function that completes filenames.  If  it
	    is `true', and completion is attempted on a string containing multi-
	    ple  partially  typed  pathname components, all ambiguous components
	    will be shown.  Otherwise, completion stops at the	first  ambiguous
	    component.

     local  This is for use with functions that complete URLs for which the cor-
	    responding	files  are available directly from the file system.  Its
	    value should consist of three strings: a hostname, the path  to  the
	    default  web  pages for the server, and the directory name used by a
	    user placing web pages within their home area.

	    For example:

		   zstyle ':completion:*' local toast \
		       /var/http/public/toast public_html

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

     mail-directory
	    If	set,  zsh will assume that mailbox files can be found in the di-
	    rectory specified.	It defaults to `~/Mail'.

     match-original
	    This is used by the _match completer.  If it is set to only,  _match
	    will  try  to generate matches without inserting a `*' at the cursor
	    position.  If set to any other non-empty value, it will first try to
	    generate matches without inserting the `*' and  if	that  yields  no
	    matches, it will try again with the `*' inserted.  If it is unset or
	    set  to  the  empty string, matching will only be performed with the
	    `*' inserted.

     matcher
	    This style is tested separately for each tag valid	in  the  current
	    context.   Its value is placed before any match specifications given
	    by the matcher-list style so can override them via the use of an  x:
	    specification.   The  value  should  be in the form described in the
	    section `Completion Matching Control' in zshcompwid(1).   For  exam-
	    ples of this, see the description of the tag-order style.

	    For  notes comparing the use of this and the matcher-list style, see
	    under the description of the tag-order style.

     matcher-list
	    This style can be set to a list of match specifications that are  to
	    be	applied  everywhere.  Match  specifications are described in the
	    section `Completion Matching Control' in zshcompwid(1).  The comple-
	    tion system will try them one after another for each  completer  se-
	    lected.   For  example,  to try first simple completion and, if that
	    generates no matches, case-insensitive completion:

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

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

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

	    It is possible to create match specifications valid  for  particular
	    completers	by  using  the third field of the context.  This applies
	    only to completers that override the global matcher-list,  which  as
	    of this writing includes only _prefix and _ignored.  For example, to
	    use  the completers _complete and _prefix but allow case-insensitive
	    completion only with _complete:

		   zstyle ':completion:*' completer _complete _prefix
		   zstyle ':completion:*:complete:*:*:*' matcher-list \
			  '' 'm:{a-zA-Z}={A-Za-z}'

	    User-defined names, as explained for the completer style, are avail-
	    able.  This makes it possible to try the same  completer  more  than
	    once with different match specifications each time.  For example, to
	    try  normal  completion  without  a match specification, then normal
	    completion with case-insensitive matching, then correction, and  fi-
	    nally partial-word completion:

		   zstyle ':completion:*' completer \
		       _complete _correct _complete:foo
		   zstyle ':completion:*:complete:*:*:*' matcher-list \
		       '' 'm:{a-zA-Z}={A-Za-z}'
		   zstyle ':completion:*:foo:*:*:*' matcher-list \
		       'm:{a-zA-Z}={A-Za-z} r:|[-_./]=* r:|=*'

	    If	the  style is unset in any context no match specification is ap-
	    plied.  Note also that some completers such as _correct and _approx-
	    imate do not use the match specifications at all, though these  com-
	    pleters  will only ever be called once even if the matcher-list con-
	    tains more than one element.

	    Where multiple specifications are useful, note that the entire  com-
	    pletion  is done for each element of matcher-list, which can quickly
	    reduce the shell's performance.  As a rough rule of  thumb,  one  to
	    three  strings will give acceptable performance.  On the other hand,
	    putting multiple space-separated values into the  same  string  does
	    not have an appreciable impact on performance.

	    If	there  is  no  current	matcher  or  it is empty, and the option
	    NO_CASE_GLOB is in effect,	the  matching  for  files  is  performed
	    case-insensitively	in  any case.  However, any matcher must explic-
	    itly specify case-insensitive matching if that is required.

	    For notes comparing the use of this and the matcher style, see under
	    the description of the tag-order style.

     max-errors
	    This is used by the _approximate and _correct completer functions to
	    determine the maximum number of errors to allow.  The completer will
	    try to generate completions by first allowing one  error,  then  two
	    errors, and so on, until either a match or matches were found or the
	    maximum number of errors given by this style has been reached.

	    If	the value for this style contains the string `numeric', the com-
	    pleter 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  comple-
	    tion 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 argu-
	    ment, so in this case the number given should be greater than  zero.
	    For  example,  `2  not-numeric' specifies that correcting completion
	    with two errors will usually be performed, but if a numeric argument
	    is given, correcting completion will not be performed.

	    The default value for this style is `2 numeric'.

     max-matches-width
	    This style is used to determine the trade off between the  width  of
	    the  display  used for matches and the width used for their descrip-
	    tions when the verbose style is in effect.	The value gives the num-
	    ber of display columns to reserve for the matches.	The  default  is
	    half the width of the screen.

	    This has the most impact when several matches have the same descrip-
	    tion and so will be grouped together.  Increasing the style will al-
	    low  more  matches	to be grouped together; decreasing it will allow
	    more of the description to be visible.

     menu   If this is `true' in the context of any of the tags defined for  the
	    current  completion  menu  completion will be used.  The value for a
	    specific tag will take precedence over that for the `default' tag.

	    If none of the values found in this way is `true' but at  least  one
	    is	set  to  `auto', the shell behaves as if the AUTO_MENU option is
	    set.

	    If one of the values is explicitly set to `false',	menu  completion
	    will  be  explicitly turned off, overriding the MENU_COMPLETE option
	    and other settings.

	    In the form `yes=num', where `yes' may be any of the  `true'  values
	    (`yes',  `true', `on' and `1'), menu completion will be turned on if
	    there are at least num matches.  In the form `yes=long',  menu  com-
	    pletion  will  be  turned on if the list does not fit on the screen.
	    This does not activate menu completion if the widget  normally  only
	    lists completions, but menu completion can be activated in that case
	    with   the	 value	 `yes=long-list'   (Typically,	the  value  `se-
	    lect=long-list' described later is more useful as it  provides  con-
	    trol over scrolling.)

	    Similarly, with any of the `false' values (as in `no=10'), menu com-
	    pletion will not be used if there are num or more matches.

	    The  value	of  this  widget also controls menu selection, as imple-
	    mented by the zsh/complist module.	The following values may  appear
	    either alongside or instead of the values above.

	    If	the  value  contains the string `select', menu selection will be
	    started unconditionally.

	    In the form `select=num', menu selection will  only  be  started  if
	    there are at least num matches.  If the values for more than one tag
	    provide a number, the smallest number is taken.

	    Menu selection can be turned off explicitly by defining a value con-
	    taining the string`no-select'.

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

	    To	turn  on menu completion or menu selection when there are a cer-
	    tain number of matches or the list of matches does not  fit  on  the
	    screen, both of `yes=' and `select=' may be given twice, once with a
	    number and once with `long' or `long-list'.

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

     muttrc
	    If set, gives the location of the mutt configuration file.	 It  de-
	    faults to `~/.muttrc'.

     numbers
	    This  is  used  with  the jobs tag.  If it is `true', the shell will
	    complete job numbers instead of the shortest unambiguous  prefix  of
	    the  job  command  text.  If the value is a number, job numbers will
	    only be used if that many words from the job  descriptions	are  re-
	    quired  to	resolve  ambiguities.  For example, if the value is `1',
	    strings will only be used if all jobs differ in the  first	word  on
	    their command lines.

     old-list
	    This  is  used by the _oldlist completer.  If it is set to `always',
	    then standard widgets which perform listing will retain the  current
	    list of matches, however they were generated; this can be turned off
	    explicitly	with the value `never', giving the behaviour without the
	    _oldlist completer.  If the style is unset, or any other value, then
	    the existing list of completions is displayed if it is not	already;
	    otherwise,	the  standard  completion list is generated; this is the
	    default behaviour of _oldlist.  However, if there is an old list and
	    this style contains the name of the completer function  that  gener-
	    ated  the list, then the old list will be used even if it was gener-
	    ated by a widget which does not do listing.

	    For example, suppose you type ^Xc to use the  _correct_word  widget,
	    which generates a list of corrections for the word under the cursor.
	    Usually, typing ^D would generate a standard list of completions for
	    the word on the command line, and show that.  With _oldlist, it will
	    instead show the list of corrections already generated.

	    As	another  example  consider  the  _match  completer: with the in-
	    sert-unambiguous style set to `true' it inserts only a common prefix
	    string, if there is any.  However, this  may  remove  parts  of  the
	    original  pattern,	so  that  further  completion could produce more
	    matches than on the first attempt.	By using the _oldlist  completer
	    and  setting  this style to _match, the list of matches generated on
	    the first attempt will be used again.

     old-matches
	    This is used by the _all_matches completer to decide if an old  list
	    of matches should be used if one exists.  This is selected by one of
	    the  `true' values or by the string `only'.  If the value is `only',
	    _all_matches will only use an old list and won't have any effect  on
	    the list of matches currently being generated.

	    If this style is set it is generally unwise to call the _all_matches
	    completer  unconditionally.   One  possible  use  is for either this
	    style or the completer style to be defined with  the  -e  option  to
	    zstyle to make the style conditional.

     old-menu
	    This  is  used by the _oldlist completer.  It controls how menu com-
	    pletion behaves when a completion has already been inserted and  the
	    user  types  a standard completion key such as TAB.  The default be-
	    haviour of _oldlist is that menu completion  always  continues  with
	    the  existing list of completions.	If this style is set to `false',
	    however, a new completion is started if the old list  was  generated
	    by a different completion command; this is the behaviour without the
	    _oldlist completer.

	    For example, suppose you type ^Xc to generate a list of corrections,
	    and  menu  completion is started in one of the usual ways.	Usually,
	    or with this style set to `false', typing TAB at  this  point  would
	    start trying to complete the line as it now appears.  With _oldlist,
	    it instead continues to cycle through the list of corrections.

     original
	    This  is  used by the _approximate and _correct completers to decide
	    if the original string should be added  as	a  possible  completion.
	    Normally,  this is done only if there are at least two possible cor-
	    rections, but if this style is set to `true', it  is  always  added.
	    Note that the style will be examined with the completer field in the
	    context name set to correct-num or approximate-num, where num is the
	    number of errors that were accepted.

     packageset
	    This  style  is  used when completing arguments of the Debian `dpkg'
	    program.  It contains an override for the default package set for  a
	    given context.  For example,

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

	    causes  available  packages, rather than only installed packages, to
	    be completed for `dpkg --status'.

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

     path-completion
	    This is used by filename completion.  By default,  filename  comple-
	    tion  examines  all components of a path to see if there are comple-
	    tions of that component.  For example, /u/b/z can  be  completed  to
	    /usr/bin/zsh.   Explicitly	setting  this  style to `false' inhibits
	    this behaviour for path components up to the /  before  the  cursor;
	    this overrides the setting of accept-exact-dirs.

	    Even with the style set to `false', it is still possible to complete
	    multiple paths by setting the option COMPLETE_IN_WORD and moving the
	    cursor back to the first component in the path to be completed.  For
	    example,  /u/b/z  can  be completed to /usr/bin/zsh if the cursor is
	    after the /u.

     pine-directory
	    If set, specifies  the  directory  containing  PINE  mailbox  files.
	    There  is  no default, since recursively searching this directory is
	    inconvenient for anyone who doesn't use PINE.

     ports  A list of Internet service names (network ports)  to  complete.   If
	    this  is  not  set, service names are taken from the file `/etc/ser-
	    vices'.

     prefix-hidden
	    This is used for certain completions which share  a  common  prefix,
	    for example command options beginning with dashes.	If it is `true',
	    the prefix will not be shown in the list of matches.

	    The default value for this style is `false'.

     prefix-needed
	    This style is also relevant for matches with a common prefix.  If it
	    is	set  to  `true'  this common prefix must be typed by the user to
	    generate the matches.

	    The style is applicable to the options,  signals,  jobs,  functions,
	    and parameters completion tags.

	    For  command  options, this means that the initial `-', `+', or `--'
	    must be typed explicitly before option names will be completed.

	    For signals, an initial `-' is required before signal names will  be
	    completed.

	    For  jobs,	an initial `%' is required before job names will be com-
	    pleted.

	    For function and parameter names, an initial `_' or `.' is	required
	    before  function  or  parameter names starting with those characters
	    will be completed.

	    The default value for this style is `false' for function and parame-
	    ter completions, and  `true' otherwise.

     preserve-prefix
	    This style is used when completing path names.  Its value should  be
	    a  pattern	matching  an initial prefix of the word to complete that
	    should be left unchanged under all circumstances.  For  example,  on
	    some  Unices  an  initial `//' (double slash) has a special meaning;
	    setting this style to the string `//' will preserve it.  As  another
	    example,  setting  this style to `?:/' under Cygwin would allow com-
	    pletion after `a:/...' and so on.

     range  This is  used  by  the  _history  completer  and  the  _history_com-
	    plete_word	bindable  command  to  decide which words should be com-
	    pleted.

	    If it is a single number, only the last N  words  from  the  history
	    will be completed.

	    If	it is a range of the form `max:slice', the last slice words will
	    be completed; then if that yields no matches, the slice words before
	    those will be tried and so on.  This process stops	either	when  at
	    least one match has been found, or max words have been tried.

	    The default is to complete all words from the history at once.

     recursive-files
	    If this style is set, its value is an array of patterns to be tested
	    against  `$PWD/':  note the trailing slash, which allows directories
	    in the pattern to be delimited unambiguously by including slashes on
	    both sides.  If an ordinary file completion fails and  the	word  on
	    the command line does not yet have a directory part to its name, the
	    style is retrieved using the same tag as for the completion just at-
	    tempted,  then  the  elements  tested against $PWD/ in turn.  If one
	    matches, then the shell reattempts completion by prepending the word
	    on the command line with each directory in the expansion of  **/*(/)
	    in	turn.	Typically  the	elements of the style will be set to re-
	    strict the number of directories beneath the current one to  a  man-
	    ageable number, for example `*/.git/*'.

	    For example,

		   zstyle ':completion:*' recursive-files '*/zsh/*'

	    If	the current directory is /home/pws/zsh/Src, then zle_tr<TAB> can
	    be completed to Zle/zle_tricky.c.

     regular
	    This style is used by the _expand_alias completer and bindable  com-
	    mand.   If	set to `true' (the default), regular aliases will be ex-
	    panded but only in command position.  If it is set to `false', regu-
	    lar aliases will never be expanded.   If it is set to `always', reg-
	    ular aliases will be expanded even if not in command position.

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

     remote-access
	    If set to `false', certain commands will be  prevented  from  making
	    Internet  connections to retrieve remote information.  This includes
	    the completion for the CVS command.

	    It is not always possible to know if connections are in  fact  to  a
	    remote site, so some may be prevented unnecessarily.

     remove-all-dups
	    The  _history_complete_word  bindable  command and the _history com-
	    pleter use this to decide if all duplicate	matches  should  be  re-
	    moved, rather than just consecutive duplicates.

     select-prompt
	    If this is set for the default tag, its value will be displayed dur-
	    ing  menu  selection  (see the menu style above) when the completion
	    list does not fit on the screen as a whole.  The same escapes as for
	    the list-prompt style are understood, except that the numbers  refer
	    to	the match or line the mark is on.  A default prompt is used when
	    the value is the empty string.

     select-scroll
	    This style is tested for the default tag and determines how  a  com-
	    pletion list is scrolled during a menu selection (see the menu style
	    above)  when  the  completion  list  does not fit on the screen as a
	    whole.  If the  value  is  `0'  (zero),  the  list	is  scrolled  by
	    half-screenfuls;  if  it is a positive integer, the list is scrolled
	    by the given number of lines; if it is a negative number,  the  list
	    is	scrolled  by  a  screenful minus the absolute value of the given
	    number of lines.  The default is to scroll by single lines.

     separate-sections
	    This style is used with the manuals tag  when  completing  names  of
	    manual  pages.   If it is `true', entries for different sections are
	    added separately using tag names of the form `manuals.X', where X is
	    the section number.  When the group-name style is  also  in  effect,
	    pages from different sections will appear separately.  This style is
	    also  used	similarly with the words style when completing words for
	    the dict command. It allows words from  different  dictionary  data-
	    bases to be added separately. See also insert-sections.

	    The default for this style is `false'.

     show-ambiguity
	    If	the  zsh/complist  module  is  loaded, this style can be used to
	    highlight the first ambiguous character  in  completion  lists.  The
	    value  is  either  a color indication such as those supported by the
	    list-colors style or, with a value of `true', a default of underlin-
	    ing is selected. The highlighting is only applied if the  completion
	    display strings correspond to the actual matches.

     show-completer
	    Tested whenever a new completer is tried.  If it is `true', the com-
	    pletion  system outputs a progress message in the listing area show-
	    ing what completer is being tried.	The message will be  overwritten
	    by	any  output when completions are found and is removed after com-
	    pletion is finished.

     single-ignored
	    This is used by the _ignored completer when there is only one match.
	    If its value is `show', the single match will be displayed	but  not
	    inserted.	If  the  value	is `menu', then the single match and the
	    original string are both added as matches  and  menu  completion  is
	    started, making it easy to select either of them.

     sort   This allows the standard ordering of matches to be overridden.

	    If	its  value is `true' or `false', sorting is enabled or disabled.
	    Additionally the values associated with the `-o' option  to  compadd
	    can  also  be listed: match, nosort, numeric, reverse.  If it is not
	    set for the context, the standard behaviour of the calling widget is
	    used.

	    The style is tested first against the  full  context  including  the
	    tag,  and if that fails to produce a value against the context with-
	    out the tag.

	    In many cases where a calling widget explicitly selects a particular
	    ordering in lieu of the default, a value of `true' is not  honoured.
	    An	example  of  where  this  is not the case is for command history
	    where the default of sorting matches chronologically may be overrid-
	    den by setting the style to `true'.

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

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

	    The  following  example  sets  special-dirs to `..' when the current
	    prefix is empty, is a single `.', or consists only of a path  begin-
	    ning with `../'.  Otherwise the value is `false'.

		   zstyle -e ':completion:*' special-dirs \
		      '[[ $PREFIX = (../)#(|.|..) ]] && reply=(..)'

     squeeze-slashes
	    If	set to `true', sequences of slashes in filename paths (for exam-
	    ple in `foo//bar') will be treated as a single slash.  This  is  the
	    usual behaviour of UNIX paths.  However, by default the file comple-
	    tion function behaves as if there were a `*' between the slashes.

     stop   If	set  to `true', the _history_complete_word bindable command will
	    stop once when reaching the beginning or end of the history.  Invok-
	    ing _history_complete_word will then wrap around to the opposite end
	    of the history.  If this style is  set  to	`false'  (the  default),
	    _history_complete_word  will  loop	immediately as in a menu comple-
	    tion.

     strip-comments
	    If set to `true', this style causes non-essential comment text to be
	    removed from completion matches.  Currently it  is	only  used  when
	    completing	e-mail	addresses where it removes any display name from
	    the addresses, cutting them down to plain user@host form.

     subst-globs-only
	    This is used by the _expand completer.  If it is set to `true',  the
	    expansion  will only be used if it resulted from globbing; hence, if
	    expansions resulted from the use of the substitute	style  described
	    below,  but  these	were not further changed by globbing, the expan-
	    sions will be rejected.

	    The default for this style is `false'.

     substitute
	    This boolean style controls whether the _expand completer will first
	    try to expand all substitutions in the string (such as `$(...)'  and
	    `${...}').

	    The default is `true'.

     suffix
	    This  is  used  by	the  _expand completer if the word starts with a
	    tilde or contains a parameter expansion.  If it is	set  to  `true',
	    the  word will only be expanded if it doesn't have a suffix, i.e. if
	    it is something  like  `~foo'  or  `$foo'  rather  than  `~foo/'  or
	    `$foo/bar',  unless  that suffix itself contains characters eligible
	    for expansion.  The default for this style is `true'.

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

	    The  values for the style are sets of space-separated lists of tags.
	    The tags in each value will be tried at the same time; if  no  match
	    is	found, the next value is used.	(See the file-patterns style for
	    an exception to this behavior.)

	    For example:

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

	    specifies that completion in command position first offers	external
	    commands  and  shell  functions.  Remaining tags will be tried if no
	    completions are found.

	    In addition to tag names, each string in the value may take  one  of
	    the following forms:

	    -	   If  any  value  consists of only a hyphen, then only the tags
		   specified in the other values are  generated.   Normally  all
		   tags  not explicitly selected are tried last if the specified
		   tags fail to generate any matches.  This means that a  single
		   value  consisting  only  of a single hyphen turns off comple-
		   tion.

	    ! tags...
		   A string starting with an exclamation mark specifies names of
		   tags that are not to be used.  The effect is the same  as  if
		   all other possible tags for the context had been listed.

	    tag:label ...
		   Here,  tag  is one of the standard tags and label is an arbi-
		   trary name.	Matches are generated as normal but the name la-
		   bel is used in contexts instead of tag.  This is  not  useful
		   in words starting with !.

		   If  the  label  starts with a hyphen, the tag is prepended to
		   the label to form the name used for lookup.	This can be used
		   to make the completion system try a	certain  tag  more  than
		   once,  supplying  different	style settings for each attempt;
		   see below for an example.

	    tag:label:description
		   As before, but description will replace the `%d' in the value
		   of the format style instead of the default  description  sup-
		   plied  by the completion function.  Spaces in the description
		   must be quoted with a backslash.  A	`%d'  appearing  in  de-
		   scription  is replaced with the description given by the com-
		   pletion function.

	    In any of the forms above the tag may be a pattern or  several  pat-
	    terns  in the form `{pat1,pat2...}'.  In this case all matching tags
	    will be used except for any given explicitly in the same string.

	    One use of these features is to try one tag more than once,  setting
	    other  styles  differently on each attempt, but still to use all the
	    other tags without having to repeat them all.  For example, to  make
	    completion of function names in command position ignore all the com-
	    pletion functions starting with an underscore the first time comple-
	    tion is tried:

		   zstyle ':completion:*:*:-command-:*:*' tag-order \
		       'functions:-non-comp *' functions
		   zstyle ':completion:*:functions-non-comp' \
		       ignored-patterns '_*'

	    On the first attempt, all tags will be offered but the functions tag
	    will  be replaced by functions-non-comp.  The ignored-patterns style
	    is set for this tag to exclude functions  starting	with  an  under-
	    score.   If  there are no matches, the second value of the tag-order
	    style is used which completes functions using the default tag,  this
	    time presumably including all function names.

	    The matches for one tag can be split into different groups.  For ex-
	    ample:

		   zstyle ':completion:*' tag-order \
		       'options:-long:long\ options
			options:-short:short\ options
			options:-single-letter:single\ letter\ options'
		   zstyle ':completion:*:options-long' \
			ignored-patterns '[-+](|-|[^-]*)'
		   zstyle ':completion:*:options-short' \
			ignored-patterns '--*' '[-+]?'
		   zstyle ':completion:*:options-single-letter' \
			ignored-patterns '???*'

	    With the group-names style set, options beginning with `--', options
	    beginning  with  a single `-' or `+' but containing multiple charac-
	    ters, and single-letter options will be displayed in separate groups
	    with different descriptions.

	    Another use of patterns is to try multiple match specifications  one
	    after another.  The matcher-list style offers something similar, but
	    it	is tested very early in the completion system and hence can't be
	    set for single commands nor for more specific contexts.  Here is how
	    to try normal completion without any  match  specification	and,  if
	    that generates no matches, try again with case-insensitive matching,
	    restricting the effect to arguments of the command foo:

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

	    First,  all the tags offered when completing after foo are tried us-
	    ing 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-insensi-
	    tive.

	    It is possible to use the -e option of the zstyle builtin command to
	    specify conditions for the use of particular tags.	For example:

		   zstyle -e '*:-command-:*' tag-order '
		       if [[ -n $PREFIX$SUFFIX ]]; then
			 reply=( )
		       else
			 reply=( - )
		       fi'

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

	    If	no  tag-order  style has been defined for a context, the strings
	    `(|*-)argument-* (|*-)option-* values' and `options' plus  all  tags
	    offered  by the completion function will be used to provide a sensi-
	    ble default behavior that causes arguments (whether  normal  command
	    arguments  or  arguments  of  options) to be completed before option
	    names for most commands.

     urls   This is used together with the  urls  tag  by  functions  completing
	    URLs.

	    If the value consists of more than one string, or if the only string
	    does  not name a file or directory, the strings are used as the URLs
	    to complete.

	    If the value contains only one string which is the name of a  normal
	    file  the URLs are taken from that file (where the URLs may be sepa-
	    rated by white space or newlines).

	    Finally, if the only string in the value names a directory, the  di-
	    rectory  hierarchy	rooted	at this directory gives the completions.
	    The top level directory should be the file access  method,	such  as
	    `http',  `ftp',  `bookmark' and so on.  In many cases the next level
	    of directories will be a filename.	The directory hierarchy can  de-
	    scend as deep as necessary.

	    For example,

		   zstyle ':completion:*' urls ~/.urls
		   mkdir -p ~/.urls/ftp/ftp.zsh.org/pub

	    allows    completion    of	 all   the   components   of   the   URL
	    ftp://ftp.zsh.org/pub after suitable commands such as `netscape'  or
	    `lynx'.   Note, however, that access methods and files are completed
	    separately, so if the hosts style is  set  hosts  can  be  completed
	    without reference to the urls style.

	    See  the  description in the function _urls itself for more informa-
	    tion (e.g. `more $^fpath/_urls(N)').

     use-cache
	    If this is set, the completion caching layer is  activated	for  any
	    completions which use it (via the _store_cache, _retrieve_cache, and
	    _cache_invalid functions).	The directory containing the cache files
	    can be changed with the cache-path style.

     use-compctl
	    If this style is set to a string not equal to false, 0, no, and off,
	    the  completion system may use any completion specifications defined
	    with the compctl builtin command.  If the style is	unset,	this  is
	    done  only if the zsh/compctl module is loaded.  The string may also
	    contain the substring `first' to use completions defined with  `com-
	    pctl  -T', and the substring `default' to use the completion defined
	    with `compctl -D'.

	    Note that this is only intended to smooth the transition  from  com-
	    pctl 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  ques-
	    tion.   For  example,  if there is a function _foo to complete argu-
	    ments to the command foo, compctl will never  be  invoked  for  foo.
	    However,  the compctl version will be tried if foo only uses default
	    completion.

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

     users  This may be set to a list of usernames to be completed.   If  it  is
	    not  set  all  usernames  will be completed.  Note that if it is set
	    only that list of users will be completed; this is because	on  some
	    systems querying all users can take a prohibitive amount of time.

     users-hosts
	    The  values  of  this  style  should  be  of the form `user@host' or
	    `user:host'. It is used for commands that need pairs  of  user-  and
	    hostnames.	 These	commands will complete usernames from this style
	    (only), and will restrict subsequent hostname  completion  to  hosts
	    paired with that user in one of the values of the style.

	    It	is  possible  to group values for sets of commands which allow a
	    remote login, such as rlogin and ssh, by using the my-accounts  tag.
	    Similarly,	values	for  sets of commands which usually refer to the
	    accounts of other people, such as talk and finger, can be grouped by
	    using the other-accounts tag.  More ambivalent commands may use  the
	    accounts tag.

     users-hosts-ports
	    Like  users-hosts  but  used for commands like telnet and containing
	    strings of the form `user@host:port'.

     verbose
	    If set, as it is by default, the completion listing is more verbose.
	    In particular many commands show descriptions for  options	if  this
	    style is `true'.

     word   This is used by the _list completer, which prevents the insertion of
	    completions  until a second completion attempt when the line has not
	    changed.  The normal way of finding out if the line has  changed  is
	    to	compare  its entire contents between the two occasions.  If this
	    style is `true', the comparison is instead	performed  only  on  the
	    current word.  Hence if completion is performed on another word with
	    the same contents, completion will not be delayed.

CONTROL FUNCTIONS
     The  initialization script compinit redefines all the widgets which perform
     completion to call the supplied widget function _main_complete.  This func-
     tion acts as a wrapper calling the  so-called  `completer'  functions  that
     generate  matches.   If  _main_complete is called with arguments, these are
     taken as the names of completer functions to be called in the order  given.
     If  no  arguments	are given, the set of functions to try is taken from the
     completer style.  For example, to use normal completion and  correction  if
     that doesn't generate any matches:

	    zstyle ':completion:*' completer _complete _correct

     after calling compinit. The default value for this style is `_complete _ig-
     nored', i.e. normally only ordinary completion is tried, first with the ef-
     fect of the ignored-patterns style and then without it.  The _main_complete
     function  uses  the  return  status of the completer functions to decide if
     other completers should be called.  If the return status is zero, no  other
     completers are tried and the _main_complete function returns.

     If  the  first argument to _main_complete is a single hyphen, the arguments
     will not be taken as names of completers.	 Instead,  the	second	argument
     gives a name to use in the completer field of the context and the other ar-
     guments give a command name and arguments to call to generate the matches.

     The  following  completer	functions are contained in the distribution, al-
     though users may write their own.	Note that in contexts the leading under-
     score is stripped, for example basic completion is performed in the context
     `:completion::complete:...'.

     _all_matches
	    This completer can be used to add a string consisting of  all  other
	    matches.   As  it  influences later completers it must appear as the
	    first completer in the list.  The list of all matches is affected by
	    the avoid-completer and old-matches styles described above.

	    It may be useful to use the _generic  function  described  below  to
	    bind _all_matches to its own keystroke, for example:

		   zle -C all-matches complete-word _generic
		   bindkey '^Xa' all-matches
		   zstyle ':completion:all-matches:*' old-matches only
		   zstyle ':completion:all-matches::::' completer _all_matches

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

		   zstyle ':completion:all-matches::::' completer \
			  _all_matches _complete
		   zstyle ':completion:all-matches:*' insert true

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

     _approximate
	    This is similar to the basic _complete completer but allows the com-
	    pletions  to  undergo corrections.	The maximum number of errors can
	    be specified by the max-errors style; see the description of approx-
	    imate matching in zshexpn(1) for how errors are  counted.	Normally
	    this  completer  will  only be tried after the normal _complete com-
	    pleter:

		   zstyle ':completion:*' completer _complete _approximate

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

	    This completer uses the tags corrections and original when	generat-
	    ing  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 gen-
	    erate the corrections and the original string, respectively.

	    The  completer  progressively increases the number of errors allowed
	    up to the limit by the max-errors style, hence if  a  completion  is
	    found  with one error, no completions with two errors will be shown,
	    and so on.	It modifies the completer name in the context  to  indi-
	    cate  the  number  of  errors being tried: on the first try the com-
	    pleter field contains `approximate-1', on the second  try  `approxi-
	    mate-2', and so on.

	    When _approximate is called from another function, the number of er-
	    rors to accept may be passed with the -a option.  The argument is in
	    the same format as the max-errors style, all in one string.

	    Note  that	this completer (and the _correct completer mentioned be-
	    low) can be quite expensive to call, especially when a large  number
	    of	errors are allowed.  One way to avoid this is to set up the com-
	    pleter style using the -e option to zstyle so that	some  completers
	    are only used when completion is attempted a second time on the same
	    string, e.g.:

		   zstyle -e ':completion:*' completer '
		     if [[ $_last_try != "$HISTNO$BUFFER$CURSOR" ]]; then
		       _last_try="$HISTNO$BUFFER$CURSOR"
		       reply=(_complete _match _prefix)
		     else
		       reply=(_ignored _correct _approximate)
		     fi'

	    This uses the HISTNO parameter and the BUFFER and CURSOR special pa-
	    rameters  that  are  available  inside zle and completion widgets to
	    find out if the command line hasn't changed since the last time com-
	    pletion was tried.	Only then are the _ignored,  _correct  and  _ap-
	    proximate completers called.

     _canonical_paths [ -A var ] [ -N ] [ -MJV12nfX ] tag descr [ paths ... ]
	    This  completion  function completes all paths given to it, and also
	    tries to offer completions which point to the same file  as  one  of
	    the  paths	given (relative path when an absolute path is given, and
	    vice versa; when ..'s are present in the word to be  completed;  and
	    some paths got from symlinks).

	    -A, if specified, takes the paths from the array variable specified.
	    Paths can also be specified on the command line as shown above.  -N,
	    if	specified,  prevents canonicalizing the paths given before using
	    them for completion, in case they are already so.  The  options  -M,
	    -J, -V, -1, -2, -n, -F, -X are passed to compadd.

	    See _description for a description of tag and descr.

     _cmdambivalent
	    Completes the remaining positional arguments as an external command.
	    The external command and its arguments are completed as separate ar-
	    guments  (in  a  manner  appropriate for completing /usr/bin/env) if
	    there are two or more remaining positional arguments on the  command
	    line,  and as a quoted command string (in the manner of system(...))
	    otherwise.	See also _cmdstring and _precommand.

	    This function takes no arguments.

     _cmdstring
	    Completes an external command as a	single	argument,  as  for  sys-
	    tem(...).

     _complete
	    This  completer generates all possible completions in a context-sen-
	    sitive manner, i.e. using the  settings  defined  with  the  compdef
	    function explained above and the current settings of all special pa-
	    rameters.  This gives the normal completion behaviour.

	    To	complete arguments of commands, _complete uses the utility func-
	    tion _normal, which is in turn responsible for finding the	particu-
	    lar  function;  it is described below.  Various contexts of the form
	    -context- are handled specifically. These are all mentioned above as
	    possible arguments to the #compdef tag.

	    Before trying to find a function for a specific  context,  _complete
	    checks  if the parameter `compcontext' is set. Setting `compcontext'
	    allows the usual completion dispatching to be  overridden  which  is
	    useful in places such as a function that uses vared for input. If it
	    is	set  to  an  array,  the  elements  are taken to be the possible
	    matches which will be completed using the tag `values' and	the  de-
	    scription  `value'.  If  it is set to an associative array, the keys
	    are used as the possible completions and the values  (if  non-empty)
	    are  used  as descriptions for the matches.  If `compcontext' is set
	    to a string containing colons, it should be  of  the  form	`tag:de-
	    scr:action'.   In  this  case the tag and descr give the tag and de-
	    scription to use and the action indicates what should  be  completed
	    in	one of the forms accepted by the _arguments utility function de-
	    scribed below.

	    Finally, if `compcontext' is set to a  string  without  colons,  the
	    value  is  taken  as the name of the context to use and the function
	    defined for that context will be called.  For this purpose, there is
	    a special context named -command-line- that completes whole  command
	    lines  (commands and their arguments).  This is not used by the com-
	    pletion system itself but is  nonetheless  handled	when  explicitly
	    called.

     _correct
	    Generate  corrections,  but  not  completions, for the current word;
	    this is similar to _approximate but will not allow any number of ex-
	    tra characters at the cursor as that completer does.  The effect  is
	    similar  to  spell-checking.   It  is based on _approximate, but the
	    completer field in the context name is correct.

	    For example, with:

		   zstyle ':completion:::::' completer \
			  _complete _correct _approximate
		   zstyle ':completion:*:correct:::' max-errors 2 not-numeric
		   zstyle ':completion:*:approximate:::' max-errors 3 numeric

	    correction will accept up to two errors.  If a numeric  argument  is
	    given,  correction	will not be performed, but correcting completion
	    will be, and will accept as many errors as given by the numeric  ar-
	    gument.   Without a numeric argument, first correction and then cor-
	    recting 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 ac-
	    cept may be given following the -a option.	The argument is  in  the
	    same form a values to the accept style, all in one string.

	    This completer function is intended to be used without the _approxi-
	    mate  completer or, as in the example, just before it.  Using it af-
	    ter the _approximate completer is useless since _approximate will at
	    least generate the corrected strings generated by the _correct  com-
	    pleter -- and probably more.

     _expand
	    This  completer function does not really perform completion, but in-
	    stead checks if the word on the command line is eligible for  expan-
	    sion  and,	if it is, gives detailed control over how this expansion
	    is done.  For this to happen, the completion system needs to be  in-
	    voked  with complete-word, not expand-or-complete (the default bind-
	    ing for TAB), as otherwise	the  string  will  be  expanded  by  the
	    shell's  internal mechanism before the completion system is started.
	    Note also this completer should be called before the _complete  com-
	    pleter function.

	    The  tags used when generating expansions are all-expansions for the
	    string containing all possible expansions,	expansions  when  adding
	    the  possible  expansions as single matches and original when adding
	    the original string from the line.	The order in which these strings
	    are generated, if at all, can be controlled by the	group-order  and
	    tag-order styles, as usual.

	    The  format string for all-expansions and for expansions may contain
	    the sequence `%o' which will be replaced by the original string from
	    the line.

	    The kind of expansion to be tried is controlled by	the  substitute,
	    glob and subst-globs-only styles.

	    It is also possible to call _expand as a function, in which case the
	    different  modes may be selected with options: -s for substitute, -g
	    for glob and -o for subst-globs-only.

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

	    This  function is also a bindable command, see the section `Bindable
	    Commands' below.

     _extensions
	    If the cursor follows the string `*.', filename extensions are  com-
	    pleted.  The extensions are taken from files in current directory or
	    a directory specified at the beginning of the current word. For  ex-
	    act  matches, completion continues to allow other completers such as
	    _expand to expand the  pattern.  The  standard  add-space  and  pre-
	    fix-hidden styles are observed.

     _external_pwds
	    Completes  current	directories  of other zsh processes belonging to
	    the current user.

	    This is intended to be used via _generic, bound to a custom key com-
	    bination. Note that pattern matching is enabled so matching is  per-
	    formed similar to how it works with the _match completer.

     _history
	    Complete  words  from  the shell's command	history.  This completer
	    can be controlled by the remove-all-dups, and sort styles as for the
	    _history_complete_word bindable command, see 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 re-
	    moved.  With this completer those matches can be reinstated,  as  if
	    no	ignored-patterns  style were set.  The completer actually gener-
	    ates its own list of matches; which completers are invoked is deter-
	    mined in the same way as for the _prefix completer.  The  single-ig-
	    nored style is also available as described above.

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

     _match
	    This completer is intended to be used after the _complete completer.
	    It	behaves  similarly  but  the string on the command line may be a
	    pattern to match against trial completions.  This gives  the  effect
	    of the GLOB_COMPLETE option.

	    Normally completion will be performed by taking the pattern from the
	    line,  inserting  a `*' at the cursor position and comparing the re-
	    sulting pattern with the possible completions generated.   This  can
	    be modified with the match-original style described above.

	    The  generated  matches  will be offered in a menu completion unless
	    the insert-unambiguous style is set to `true'; see	the  description
	    above for other options for this style.

	    Note  that	matcher  specifications  defined globally or used by the
	    completion functions (the styles matcher-list and matcher) will  not
	    be used.

     _menu  This  completer  was  written as simple example function to show how
	    menu completion can be enabled in shell code. However,  it	has  the
	    notable  effect of disabling menu selection which can be useful with
	    _generic based widgets. It should be used as the first completer  in
	    the  list.	 Note  that  this  is  independent of the setting of the
	    MENU_COMPLETE option and does not work with the other  menu  comple-
	    tion  widgets such as reverse-menu-complete, or accept-and-menu-com-
	    plete.

     _oldlist
	    This completer controls how the standard completion  widgets  behave
	    when  there  is  an existing list of completions which may have been
	    generated by a special completion (i.e. a  separately-bound  comple-
	    tion  command).   It allows the ordinary completion keys to continue
	    to use the list of completions thus generated, instead of  producing
	    a  new list of ordinary contextual completions.  It should appear in
	    the list of completers before any  of  the	widgets  which	generate
	    matches.  It uses two styles: old-list and old-menu, see the section
	    `Completion System Configuration' above.

     _precommand
	    Complete  an  external  command  in word-separated arguments, as for
	    exec and /usr/bin/env.

     _prefix
	    This completer can be used to try completion with the suffix (every-
	    thing after the cursor) ignored.  In other words,  the  suffix  will
	    not be considered to be part of the word to complete.  The effect is
	    similar to the expand-or-complete-prefix command.

	    The  completer style is used to decide which other completers are to
	    be called to generate matches.  If this style is unset, the list  of
	    completers set for the current context is used -- except, of course,
	    the  _prefix  completer  itself.  Furthermore, if this completer ap-
	    pears more than once in the list of completers only those completers
	    not already tried by the last invocation of _prefix will be called.

	    For example, consider this global completer style:

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

	    Here, the _prefix completer tries normal completion but ignoring the
	    suffix.  If that doesn't generate any matches, and neither does  the
	    call  to  the  _correct completer after it, _prefix will be called a
	    second time and, now only trying correction with the suffix ignored.
	    On the second invocation the completer part of the	context  appears
	    as `foo'.

	    To	use  _prefix  as  the last resort and try only normal completion
	    when it is invoked:

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

	    The add-space style is also respected.  If it is set to `true'  then
	    _prefix  will  insert a space between the matches generated (if any)
	    and the suffix.

	    Note that this completer is only useful if the COMPLETE_IN_WORD  op-
	    tion  is  set; otherwise, the cursor will be moved to the end of the
	    current word before the completion code is called  and  hence  there
	    will be no suffix.

     _user_expand
	    This  completer  behaves  similarly to the _expand completer but in-
	    stead performs expansions defined by users.   The  styles  add-space
	    and  sort  styles  specific to the _expand completer are usable with
	    _user_expand in addition to other styles handled more  generally  by
	    the completion system.  The tag all-expansions is also available.

	    The  expansion  depends on the array style user-expand being defined
	    for the current context; remember that the context for completers is
	    less specific than that for contextual completion as the  full  con-
	    text  has  not  yet been determined.  Elements of the array may have
	    one of the following forms:

	    $hash

		   hash is the name of an associative array.  Note this is not a
		   full parameter expression, merely a	$,  suitably  quoted  to
		   prevent immediate expansion, followed by the name of an asso-
		   ciative  array.  If the trial expansion word matches a key in
		   hash, the resulting expansion is the corresponding value.
	    _func

		   _func is the name of a shell function whose name  must  begin
		   with _ but is not otherwise special to the completion system.
		   The	function  is  called with the trial word as an argument.
		   If the word is to be expanded, the function	should	set  the
		   array  reply to a list of expansions.  Optionally, it can set
		   REPLY to a word that will be used as a  description	for  the
		   set	of expansions.	The return status of the function is ir-
		   relevant.

BINDABLE COMMANDS
     In addition to the context-dependent completions provided,  which	are  ex-
     pected  to  work in an intuitively obvious way, there are a few widgets im-
     plementing 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 comple-
	    tion bindings in bash.  The last character of the binding determines
	    what is completed: `!', command names; `$',  environment  variables;
	    `@',  host	names;	`/',  file  names; `~' user names.  In bash, the
	    binding preceded by `\e' gives  completion,  and  preceded	by  `^X'
	    lists  options.   As  some of these bindings clash with standard zsh
	    bindings, only `\e~' and `^X~' are bound by  default.   To	add  the
	    rest,  the	following  should  be added to .zshrc after compinit has
	    been run:

		   for key in '!' '$' '@' '/' '~'; do
		     bindkey "\e$key" _bash_complete-word
		     bindkey "^X$key" _bash_list-choices
		   done

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

     _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 contex-
	    tual completions as possible choices. This stores the  string  `cor-
	    rect-word'	in the function field of the context name and then calls
	    the _correct completer.

     _expand_alias (^Xa)
	    This function can be used as a completer and as a bindable	command.
	    It	expands  the word the cursor is on if it is an alias.  The types
	    of alias expanded can be controlled with the styles regular,  global
	    and disabled.

	    When used as a bindable command there is one additional feature that
	    can  be  selected  by setting the complete style to `true'.  In this
	    case, if the word is not the name of an alias,  _expand_alias  tries
	    to	complete the word to a full alias name without expanding it.  It
	    leaves the cursor directly after the completed word so that invoking
	    _expand_alias once more will expand the now-complete alias name.

     _expand_word (^Xe)
	    Performs expansion on the current word:  equivalent to the	standard
	    expand-word  command, but using the _expand completer.  Before call-
	    ing it, the function field of the context is set to `expand-word'.

     _generic
	    This function is not defined as a widget and not bound  by	default.
	    However,  it  can be used to define a widget and will then store the
	    name of the widget in the function field of the context and call the
	    completion system.	This allows custom completion widgets with their
	    own set of style settings to be defined easily.  For example, to de-
	    fine a widget that performs normal completion and starts menu selec-
	    tion:

		   zle -C foo complete-word _generic
		   bindkey '...' foo
		   zstyle ':completion:foo:*' menu yes select=1

	    Note in particular that the completer style may be set for the  con-
	    text in order to change the set of functions used to generate possi-
	    ble matches.  If _generic is called with arguments, those are passed
	    through  to  _main_complete  as  the  list of completers in place of
	    those defined by the completer style.

     _history_complete_word (\e/)
	    Complete words from the shell's command history. This uses the list,
	    remove-all-dups, sort, and stop styles.

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

     _next_tags (^Xn)
	    This  command  alters  the	set of matches used to that for the next
	    tag, or set of tags, either as given by the tag-order  style  or  as
	    set  by  default;  these  matches  would otherwise not be available.
	    Successive invocations of the command  cycle  through  all	possible
	    sets of tags.

     _read_comp (^X^R)
	    Prompt  the user for a string, and use that to perform completion on
	    the current word.  There  are  two	possibilities  for  the  string.
	    First,  it	can be a set of words beginning `_', for example `_files
	    -/', in which case the function with any arguments will be called to
	    generate the completions.  Unambiguous parts of  the  function  name
	    will  be completed automatically (normal completion is not available
	    at this point) until a space is typed.

	    Second, any other string will be passed as a  set  of  arguments  to
	    compadd  and should hence be an expression specifying what should be
	    completed.

	    A very restricted set of editing commands is available when  reading
	    the  string:  `DEL' and `^H' delete the last character; `^U' deletes
	    the line, and `^C' and `^G' abort the function, while `RET'  accepts
	    the completion.  Note the string is used verbatim as a command line,
	    so arguments must be quoted in accordance with standard shell rules.

	    Once  a  string  has been read, the next call to _read_comp will use
	    the existing string instead of reading a new one.  To  force  a  new
	    string to be read, call _read_comp with a numeric argument.

     _complete_debug (^X?)
	    This  widget  performs ordinary completion, but captures in a tempo-
	    rary file a trace of the shell commands executed by  the  completion
	    system.   Each  completion	attempt gets its own file.  A command to
	    view each of these files is pushed onto the editor buffer stack.

     _complete_help (^Xh)
	    This widget displays information about the context names, the  tags,
	    and  the  completion  functions  used when completing at the current
	    cursor position. If given a numeric argument other	than  1  (as  in
	    `ESC-2  ^Xh'),  then the styles used and the contexts for which they
	    are used will be shown, too.

	    Note that the information about styles may be incomplete; it depends
	    on the information available from the completion  functions  called,
	    which  in turn is determined by the user's own styles and other set-
	    tings.

     _complete_help_generic
	    Unlike other commands listed here, this must be created as a  normal
	    ZLE  widget  rather than a completion widget (i.e. with zle -N).  It
	    is used for generating help with a widget bound to the _generic wid-
	    get that is described above.

	    If this widget is created using the name of the function, as  it  is
	    by default, then when executed it will read a key sequence.  This is
	    expected  to  be  bound to a call to a completion function that uses
	    the _generic widget.  That widget will be executed, and  information
	    provided  in the same format that the _complete_help widget displays
	    for contextual completion.

	    If the widget's name contains debug, for example if it is created as
	    `zle -N  _complete_debug_generic  _complete_help_generic',	it  will
	    read  and  execute the keystring for a generic widget as before, but
	    then generate debugging information as done by  _complete_debug  for
	    contextual completion.

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

	    The    widget    works    by    setting    the    shell    parameter
	    ZSH_TRACE_GENERIC_WIDGET  which  is read by _generic.  Unsetting the
	    parameter cancels any pending effect of the noread form.

	    For example, after executing the following:

		   zle -N _complete_debug_generic _complete_help_generic
		   bindkey '^x:' _complete_debug_generic

	    typing `C-x :' followed by the key sequence  for  a  generic  widget
	    will cause trace output for that widget to be saved to a file.

     _complete_tag (^Xt)
	    This widget completes symbol tags created by the etags or ctags pro-
	    grammes  (note  there  is no connection with the completion system's
	    tags) stored in a file TAGS, in the format used by etags,  or  tags,
	    in the format created by ctags.  It will look back up the path hier-
	    archy  for	the  first occurrence of either file; if both exist, the
	    file TAGS is preferred.  You can specify the full path to a TAGS  or
	    tags  file	by  setting the parameter $TAGSFILE or $tagsfile respec-
	    tively.  The corresponding completion tags used are etags and vtags,
	    after emacs and vi respectively.

UTILITY FUNCTIONS
     Descriptions follow for utility functions that may be useful  when  writing
     completion  functions.   If functions are installed in subdirectories, most
     of these reside in the Base subdirectory.	Like the example  functions  for
     commands  in the distribution, the utility functions generating matches all
     follow the convention of returning status zero if	they  generated  comple-
     tions and non-zero if no matching completions could be added.

     _absolute_command_paths
	    This  function completes external commands as absolute paths (unlike
	    _command_names -e which completes their basenames).  It takes no ar-
	    guments.

     _all_labels [ -x ] [ -12VJ ] tag name descr [ command arg ... ]
	    This is a convenient interface to the  _next_label	function  below,
	    implementing the loop shown in the _next_label example.  The command
	    and  its  arguments are called to generate the matches.  The options
	    stored in the parameter name will automatically be inserted into the
	    args passed to the command.  Normally, they are put  directly  after
	    the command, but if one of the args is a single hyphen, they are in-
	    serted directly before that.  If the hyphen is the last argument, it
	    will be removed from the argument list before the command is called.
	    This  allows  _all_labels  to  be used in almost all cases where the
	    matches can be generated by a single call  to  the	compadd  builtin
	    command or by a call to one of the utility functions.

	    For example:

		   local expl
		   ...
		   if _requested foo; then
		     ...
		     _all_labels foo expl '...' compadd ... - $matches
		   fi

	    Will  complete the strings from the matches parameter, using compadd
	    with additional options which will take precedence over those gener-
	    ated by _all_labels.

     _alternative [ -O name ] [ -C name ] spec ...
	    This function is useful in simple  cases  where  multiple  tags  are
	    available.	 Essentially it implements a loop like the one described
	    for the _tags function below.

	    The tags to use and the action to perform if a tag is requested  are
	    described using the specs which are of the form: `tag:descr:action'.
	    The  tags  are  offered using _tags and if the tag is requested, the
	    action is executed with the given description  descr.   The  actions
	    are  those	accepted  by  the _arguments function (described below),
	    with the following exceptions:
	    *	   The `->state' and `=...' forms are not supported.

	    *	   The `((a\:bar b\:baz))' form does not need the  colon  to  be
		   escaped, since the specs have no colon-separated fields after
		   the action.

	    For example, the action may be a simple function call:

		   _alternative \
		       'users:user:_users' \
		       'hosts:host:_hosts'

	    offers usernames and hostnames as possible matches, generated by the
	    _users and _hosts functions respectively.

	    Like  _arguments,  this function uses _all_labels to execute the ac-
	    tions, which will loop over all sets of tags.  Special  handling  is
	    only  required  if there is an additional valid tag, for example in-
	    side a function called from _alternative.

	    The option `-O name' is used in the same way as  by  the  _arguments
	    function.	In  other  words, the elements of the name array will be
	    passed to compadd when executing an action.

	    Like _tags this function supports the -C option to give a  different
	    name for the argument context field.

     _arguments [ -nswWCRS ] [ -A pat ] [ -O name ] [ -M matchspec ]
		[ : ] spec ...
     _arguments [ opt ... ] -- [ -l ] [ -i pats ] [ -s pair ]
		[ helpspec ...]
	    This  function can be used to give a complete specification for com-
	    pletion for a command whose arguments follow  standard  UNIX  option
	    and argument conventions.

	    Options Overview

	    Options  to _arguments itself must be in separate words, i.e. -s -w,
	    not -sw.  The options are followed by specs  that  describe  options
	    and  arguments of the analyzed command.  To avoid ambiguity, all op-
	    tions to _arguments itself may be separated from the spec forms by a
	    single colon.

	    The `--' form is used to intuit spec forms from the help  output  of
	    the  command  being analyzed, and is described in detail below.  The
	    opts for the `--' form are otherwise the same options as  the  first
	    form.   Note  that	`-s'  following `--' has a distinct meaning from
	    `-s' preceding `--', and both may appear.

	    The option switches -s, -S, -A, -w, and  -W  affect  how  _arguments
	    parses the analyzed command line's options.  These switches are use-
	    ful for commands with standard argument parsing.

	    The options of _arguments have the following meanings:

	    -n	   With  this  option,	_arguments sets the parameter NORMARG to
		   the position of the first normal argument in the  $words  ar-
		   ray, i.e. the position after the end of the options.  If that
		   argument  has  not  been  reached, NORMARG is set to -1.  The
		   caller should declare `integer NORMARG' if the -n  option  is
		   passed; otherwise the parameter is not used.

	    -s	   Enable  option  stacking  for  single-letter options, whereby
		   multiple single-letter options may be combined into a  single
		   word.  For example, the two options `-x' and `-y' may be com-
		   bined  into a single word `-xy'.  By default, every word cor-
		   responds to a single option name (`-xy' is  a  single  option
		   named `xy').

		   Options  beginning with a single hyphen or plus sign are eli-
		   gible for stacking; words beginning with two hyphens are not.

		   Note that -s after -- has a different meaning, which is docu-
		   mented in the segment entitled `Deriving spec forms from  the
		   help output'.

	    -w	   In  combination with -s, allow option stacking even if one or
		   more of the options take arguments.	For example, if -x takes
		   an argument, with no -s, `-xy' is considered as a single (un-
		   handled) option; with -s, -xy is an option with the	argument
		   `y'; with both -s and -w, -xy is the option -x and the option
		   -y  with  arguments	to -x (and to -y, if it takes arguments)
		   still to come in subsequent words.

	    -W	   This option takes -w a stage further:  it is possible to com-
		   plete single-letter options even after an argument  that  oc-
		   curs  in  the  same	word.  However, it depends on the action
		   performed whether options will really be  completed	at  this
		   point.   For more control, use a utility function like _guard
		   as part of the action.

	    -C	   Modify the curcontext parameter for an  action  of  the  form
		   `->state'.  This is discussed in detail below.

	    -R	   Return status 300 instead of zero when a $state is to be han-
		   dled, in the `->string' syntax.

	    -S	   Do  not  complete options after a `--' appearing on the line,
		   and ignore the `--'.  For example, with -S, in the line

			  foobar -x -- -y

		   the `-x' is considered an option, the `-y' is  considered  an
		   argument, and the `--' is considered to be neither.

	    -A pat
		   Do  not  complete options after the first non-option argument
		   on the line.  pat is a pattern matching all strings which are
		   not to be taken as arguments.  For example,	to  make  _argu-
		   ments  stop	completing  options after the first normal argu-
		   ment, but ignoring all strings starting with a hyphen even if
		   they are not described by one of the optspecs,  the	form  is
		   `-A "-*"'.

	    -O name
		   Pass the elements of the array name as arguments to functions
		   called  to  execute actions.  This is discussed in detail be-
		   low.

	    -M matchspec
		   Use the match specification matchspec for  completing  option
		   names  and values.  The default matchspec allows partial word
		   completion after `_' and `-', such as  completing  `-f-b'  to
		   `-foo-bar'.	The default matchspec is:
		   r:|[_-]=* r:|=*

	    -0	   When  populating  values of the `opt_args' associative array,
		   don't backslash-escape colons and  backslashes  and	use  NUL
		   rather than colon for joining multiple values. This option is
		   described  in more detail below, under the heading specs: ac-
		   tions.

	    specs: overview

	    Each of the following forms is a spec describing individual sets  of
	    options or arguments on the command line being analyzed.

	    n:message:action
	    n::message:action
		   This describes the n'th normal argument.  The message will be
		   printed  above the matches generated and the action indicates
		   what can be completed in this position (see below).	If there
		   are two colons before the message the argument  is  optional.
		   If  the  message  contains  only white space, nothing will be
		   printed above the matches unless the action adds an	explana-
		   tion string itself.

	    :message:action
	    ::message:action
		   Similar,  but  describes  the  next argument, whatever number
		   that happens to be.	If all arguments are specified	in  this
		   form in the correct order the numbers are unnecessary.

	    *:message:action
	    *::message:action
	    *:::message:action
		   This  describes  how arguments (usually non-option arguments,
		   those not beginning with - or +) are  to  be  completed  when
		   neither  of	the first two forms was provided.  Any number of
		   arguments can be completed in this fashion.

		   With two colons before the message, the words  special  array
		   and	the CURRENT special parameter are modified to refer only
		   to the normal arguments when the action is executed or evalu-
		   ated.  With three colons before the message they are modified
		   to refer only to the normal arguments  covered  by  this  de-
		   scription.

	    optspec
	    optspec:...
		   This  describes  an option.	The colon indicates handling for
		   one or more arguments to the option; if it  is  not	present,
		   the option is assumed to take no arguments.

		   The	following  forms  are available for the initial optspec,
		   whether or not the option has arguments.

		   *optspec
			  Here optspec is one  of  the	remaining  forms  below.
			  This	indicates the following optspec may be repeated.
			  Otherwise  if  the  corresponding  option  is  already
			  present  on the command line to the left of the cursor
			  it will not be offered again.

		   -optname
		   +optname
			  In the simplest form the optspec is  just  the  option
			  name	beginning  with  a minus or a plus sign, such as
			  `-foo'.  The first argument for the  option  (if  any)
			  must	follow as a separate word directly after the op-
			  tion.

			  Either of `-+optname' and `+-optname' can be	used  to
			  specify that -optname and +optname are both valid.

			  In all the remaining forms, the leading `-' may be re-
			  placed by or paired with `+' in this way.

		   -optname-
			  The  first  argument	of the option must come directly
			  after the option name in the same word.  For	example,
			  `-foo-:...'  specifies  that	the completed option and
			  argument will look like `-fooarg'.

		   -optname+
			  The first argument may appear immediately  after  opt-
			  name	in  the  same  word, or may appear as a separate
			  word after the option.  For example, `-foo+:...' spec-
			  ifies that the completed option and argument will look
			  like either `-fooarg' or `-foo arg'.

		   -optname=
			  The argument may appear as the next word, or	in  same
			  word	as the option name provided that it is separated
			  from it by an equals sign, for example  `-foo=arg'  or
			  `-foo arg'.

		   -optname=-
			  The argument to the option must appear after an equals
			  sign	in  the  same  word, and may not be given in the
			  next argument.

		   optspec[explanation]
			  An explanation string may be appended to  any  of  the
			  preceding  forms  of optspec by enclosing it in brack-
			  ets, as in `-q[query operation]'.

			  The verbose style is used to decide whether the expla-
			  nation strings are displayed with the option in a com-
			  pletion listing.

			  If no bracketed explanation string is  given	but  the
			  auto-description style is set and only one argument is
			  described  for this optspec, the value of the style is
			  displayed, with any appearance of the sequence `%d' in
			  it replaced by the message of the  first  optarg  that
			  follows the optspec; see below.

		   It  is  possible for options with a literal `+' or `=' to ap-
		   pear, but that character must be quoted, for example `-\+'.

		   Each optarg following an optspec must take one of the follow-
		   ing forms:

		   :message:action
		   ::message:action
			  An argument to the  option;  message	and  action  are
			  treated as for ordinary arguments.  In the first form,
			  the  argument  is mandatory, and in the second form it
			  is optional.

			  This group may be repeated for options which take mul-
			  tiple  arguments.   In  other   words,   :message1:ac-
			  tion1:message2:action2 specifies that the option takes
			  two arguments.

		   :*pattern:message:action
		   :*pattern::message:action
		   :*pattern:::message:action
			  This	describes multiple arguments.  Only the last op-
			  targ for an option taking multiple  arguments  may  be
			  given  in  this  form.   If the pattern is empty (i.e.
			  :*:), all the remaining words on the line  are  to  be
			  completed  as  described by the action; otherwise, all
			  the words up to and including a word matching the pat-
			  tern are to be completed using the action.

			  Multiple colons are treated as for the  `*:...'  forms
			  for  ordinary arguments:  when the message is preceded
			  by two colons, the words special array and the CURRENT
			  special parameter are modified during the execution or
			  evaluation of the action to refer only  to  the  words
			  after the option.  When preceded by three colons, they
			  are  modified  to  refer  only to the words covered by
			  this description.

	    Any literal colon in an optname, message, or action must be preceded
	    by a backslash, `\:'.

	    Each of the forms above may be preceded by a list in parentheses  of
	    option  names  and	argument numbers.  If the given option is on the
	    command line, the options and  arguments  indicated  in  parentheses
	    will  not  be  offered.  For example, `(-two -three 1)-one:...' com-
	    pletes the option `-one'; if this appears on the command  line,  the
	    options  -two and -three and the first ordinary argument will not be
	    completed after it.  `(-foo):...'  specifies  an  ordinary	argument
	    completion;  -foo  will not be completed if that argument is already
	    present.

	    Other items may appear in the list of excluded options  to	indicate
	    various  other  items  that  should  not be applied when the current
	    specification is matched: a single star (*) for the  rest  arguments
	    (i.e. a specification of the form `*:...'); a colon (:) for all nor-
	    mal  (non-option-) arguments; and a hyphen (-) for all options.  For
	    example, if `(*)' appears before an option and the option appears on
	    the command line, the list of remaining arguments  (those  shown  in
	    the above table beginning with `*:') will not be completed.

	    To	aid in reuse of specifications, it is possible to precede any of
	    the forms above with `!'; then the form will no longer be completed,
	    although if the option or argument appears on the command line  they
	    will  be skipped as normal.  The main use for this is when the argu-
	    ments are given by an array, and _arguments is called repeatedly for
	    more specific contexts: on the first  call	`_arguments  $global_op-
	    tions'  is	used,  and on subsequent calls `_arguments !$^global_op-
	    tions'.

	    specs: actions

	    In each of the forms above the  action  determines	how  completions
	    should  be generated.  Except for the `->string' form below, the ac-
	    tion will be executed by calling the _all_labels function to process
	    all tag labels.  No special handling of  tags  is  needed  unless  a
	    function call introduces a new one.

	    The functions called to execute actions will be called with the ele-
	    ments of the array named by the `-O name' option as arguments.  This
	    can  be  used,  for example, to pass the same set of options for the
	    compadd builtin to all actions.

	    The forms for action are as follows.

	     (single unquoted space)
		   This is useful where an argument is required but  it  is  not
		   possible  or  desirable to generate matches for it.	The mes-
		   sage will be displayed but no completions listed.  Note  that
		   even  in  this  case  the  colon at the end of the message is
		   needed; it may only be omitted when neither a message nor  an
		   action is given.

	    (item1 item2 ...)
		   One of a list of possible matches, for example:

			  :foo:(foo bar baz)

	    ((item1\:desc1 ...))
		   Similar to the above, but with descriptions for each possible
		   match.  Note the backslash before the colon.  For example,

			  :foo:((a\:bar b\:baz))

		   The	matches  will be listed together with their descriptions
		   if the description style is set with the values  tag  in  the
		   context.

	    ->string
		   In  this form, _arguments processes the arguments and options
		   and then returns control to the calling function with parame-
		   ters set to indicate the state  of  processing;  the  calling
		   function  then makes its own arrangements for generating com-
		   pletions.  For example, functions that implement a state  ma-
		   chine can use this type of action.

		   Where  _arguments encounters action in the `->string' format,
		   it will strip all leading and trailing whitespace from string
		   and set the array state to the set of all strings  for  which
		   an  action  is  to  be  performed.  The elements of the array
		   state_descr are assigned the corresponding message field from
		   each optarg containing such an action.

		   By default and in common with all other well behaved  comple-
		   tion functions, _arguments returns status zero if it was able
		   to add matches and non-zero otherwise. However, if the -R op-
		   tion is given, _arguments will instead return a status of 300
		   to indicate that $state is to be handled.

		   In  addition to $state and $state_descr, _arguments also sets
		   the global parameters `context', `line' and `opt_args' as de-
		   scribed below, and does not reset any  changes  made  to  the
		   special  parameters such as PREFIX and words.  This gives the
		   calling function the choice of resetting these parameters  or
		   propagating changes in them.

		   A  function	calling _arguments with at least one action con-
		   taining a `->string' must therefore declare appropriate local
		   parameters:

			  local context state state_descr line
			  typeset -A opt_args

		   to prevent _arguments from altering the global environment.

	    {eval-string}
		   A string in braces is evaluated as  shell  code  to	generate
		   matches.   If  the  eval-string itself does not begin with an
		   opening parenthesis or brace it is split into separate  words
		   before execution.

	    = action
		   If  the action starts with `= ' (an equals sign followed by a
		   space), _arguments will insert the contents of  the	argument
		   field  of the current context as the new first element in the
		   words special array and increment the value	of  the  CURRENT
		   special  parameter.	This has the effect of inserting a dummy
		   word onto the completion command line while not changing  the
		   point at which completion is taking place.

		   This  is most useful with one of the specifiers that restrict
		   the words on the command line on which the action is to oper-
		   ate (the two- and three-colon forms above).	 One  particular
		   use	is  when  an  action  itself  causes _arguments on a re-
		   stricted range; it is necessary to use this trick  to  insert
		   an  appropriate  command  name  into the range for the second
		   call to _arguments to be able to parse the line.

	     word...
	    word...
		   This covers all forms other than those above.  If the  action
		   starts  with a space, the remaining list of words will be in-
		   voked unchanged.

		   Otherwise it will be invoked with some extra  strings  placed
		   after  the first word; these are to be passed down as options
		   to the compadd builtin.  They ensure that the state specified
		   by _arguments, in particular the descriptions of options  and
		   arguments,  is  correctly  passed  to the completion command.
		   These additional arguments are taken from the array parameter
		   `expl'; this will be set up before executing the  action  and
		   hence may be referred to inside it, typically in an expansion
		   of  the form `$expl[@]' which preserves empty elements of the
		   array.

	    During the performance of the action the array `line' will be set to
	    the normal arguments from the command line, i.e. the words from  the
	    command  line after the command name excluding all options and their
	    arguments.	Options are stored in the associative  array  `opt_args'
	    with option names as keys and their arguments as the values.  By de-
	    fault,  all  colons  and  backslashes  in the value are escaped with
	    backslashes, and if an option has multiple arguments  (for	example,
	    when  using an optspec of the form `*optspec'), they are joined with
	    (unescaped) colons.  However, if the -0 option was passed, no  back-
	    slash escaping is performed, and multiple values are joined with NUL
	    bytes.  For example, after `zsh -o foo:foo -o bar:bar -o <TAB>', the
	    contents of `opt_args' would be

		   typeset -A opt_args=( [-o]='foo\:foo:bar\:bar:' )

	    by default, and

		   typeset -A opt_args=( [-o]=$'foo:foo\x00bar:bar\x00' )

	    if _arguments had been called with the -0 option.

	    The  parameter  `context' is set when returning to the calling func-
	    tion to perform an action of the form `->string'.  It is set  to  an
	    array of elements corresponding to the elements of $state.	Each el-
	    ement  is a suitable name for the argument field of the context: ei-
	    ther a string of the form `option-opt-n' for the  n'th  argument  of
	    the  option  -opt, or a string of the form `argument-n' for the n'th
	    argument.  For `rest' arguments, that is those in the  list  at  the
	    end  not  handled by position, n is the string `rest'.  For example,
	    when completing the argument of the -o  option,  the  name	is  `op-
	    tion-o-1',	while for the second normal (non-option-) argument it is
	    `argument-2'.

	    Furthermore, during the evaluation of the action the context name in
	    the curcontext parameter is altered to append the same  string  that
	    is stored in the context parameter.

	    The  option  -C  tells _arguments to modify the curcontext parameter
	    for an action of the form `->state'.  This is the standard parameter
	    used to keep track of the current context.	Here  it  (and	not  the
	    context array) should be made local to the calling function to avoid
	    passing  back  the	modified  value and should be initialised to the
	    current value at the start of the function:

		   local curcontext="$curcontext"

	    This is useful where it is not possible for multiple  states  to  be
	    valid together.

	    Grouping Options

	    Options  can  be grouped to simplify exclusion lists. A group is in-
	    troduced with `+' followed by a name for the group in the subsequent
	    word. Whole groups can then be referenced in an exclusion list or  a
	    group name can be used to disambiguate between two forms of the same
	    option. For example:

		   _arguments \
		       '(group2--x)-a' \
		     + group1 \
		       -m \
		       '(group2)-n' \
		     + group2 \
		       -x -y

	    If	the  name of a group is specified in the form `(name)' then only
	    one value from that group will ever be completed; more formally, all
	    specifications are mutually exclusive to all other specifications in
	    that group. This is useful for defining options that are aliases for
	    each other. For example:

		   _arguments \
		       -a -b \
		     + '(operation)' \
		       {-c,--compress}'[compress]' \
		       {-d,--decompress}'[decompress]' \
		       {-l,--list}'[list]'

	    If an option in a group appears on the command line, it is stored in
	    the associative array `opt_args' with 'group-option' as a  key.   In
	    the  example  above, a key `operation--c' is used if the option `-c'
	    is present on the command line.

	    Specifying Multiple Sets of Arguments

	    It is possible to specify multiple sets  of  options  and  arguments
	    with  the sets separated by single hyphens. This differs from groups
	    in that sets are considered to be mutually exclusive of each other.

	    Specifications before the first set and from any group are common to
	    all sets. For example:

		   _arguments \
		       -a \
		     - set1 \
		       -c \
		     - set2 \
		       -d \
		       ':arg:(x2 y2)'

	    This defines two sets.  When the command line  contains  the  option
	    `-c', the `-d' option and the argument will not be considered possi-
	    ble  completions.	When it contains `-d' or an argument, the option
	    `-c' will not be considered.  However, after  `-a'	both  sets  will
	    still be considered valid.

	    As	for groups, the name of a set may appear in exclusion lists, ei-
	    ther alone or preceding a normal option or argument specification.

	    The completion code has to parse the  command  line  separately  for
	    each  set.	This can be slow so sets should only be used when neces-
	    sary.  A useful alternative is often an  option  specification  with
	    rest-arguments  (as  in `-foo:*:...'); here the option -foo swallows
	    up all remaining arguments as described by the optarg definitions.

	    Deriving spec forms from the help output

	    The option `--' allows _arguments to work out the names of long  op-
	    tions that support the `--help' option which is standard in many GNU
	    commands.  The command word is called with the argument `--help' and
	    the  output examined for option names.  Clearly, it can be dangerous
	    to pass this to commands which may not support this  option  as  the
	    behaviour of the command is unspecified.

	    In addition to options, `_arguments --' will try to deduce the types
	    of	arguments  available  for  options  when the form `--opt=val' is
	    valid.  It is also possible to provide hints by examining  the  help
	    text  of  the  command and adding helpspec of the form `pattern:mes-
	    sage:action'; note that other _arguments spec forms  are  not  used.
	    The  pattern  is matched against the help text for an option, and if
	    it matches the message and action are used	as  for  other	argument
	    specifiers.   The special case of `*:' means both message and action
	    are empty, which has the effect of causing	options  having  no  de-
	    scription  in the help output to be ordered in listings ahead of op-
	    tions that have a description.

	    For example:

		   _arguments -- '*\*:toggle:(yes no)' \
				 '*=FILE*:file:_files' \
				 '*=DIR*:directory:_files -/' \
				 '*=PATH*:directory:_files -/'

	    Here, `yes' and `no' will be completed as the  argument  of  options
	    whose  description	ends in a star; file names will be completed for
	    options that contain the substring `=FILE' in the  description;  and
	    directories will be completed for options whose description contains
	    `=DIR'  or	`=PATH'.   The last three are in fact the default and so
	    need not be given explicitly, although it is  possible  to	override
	    the use of these patterns.	A typical help text which uses this fea-
	    ture is:

		     -C, --directory=DIR	  change to directory DIR

	    so	that  the above specifications will cause directories to be com-
	    pleted after `--directory', though not after `-C'.

	    Note also that _arguments tries to find out automatically if the ar-
	    gument for an option is optional.  This can be specified  explicitly
	    by doubling the colon before the message.

	    If	the pattern ends in `(-)', this will be removed from the pattern
	    and the action will be used only directly after the `=', not in  the
	    next  word.  This is the behaviour of a normal specification defined
	    with the form `=-'.

	    By default, the command (with the option `--help') is run after  re-
	    setting  all the locale categories (except for LC_CTYPE) to `C'.  If
	    the localized help output is known to work, the option `-l'  can  be
	    specified  after  the  `_arguments --' so that the command is run in
	    the current locale.

	    The `_arguments --' can be followed by the option `-i  patterns'  to
	    give  patterns  for options which are not to be completed.	The pat-
	    terns can be given as the name of an array parameter or as a literal
	    list in parentheses.  For example,

		   _arguments -- -i \
		       "(--(en|dis)able-FEATURE*)"

	    will cause completion to ignore the options  `--enable-FEATURE'  and
	    `--disable-FEATURE' (this example is useful with GNU configure).

	    The  `_arguments  --'  form  can  also be followed by the option `-s
	    pair' to describe option aliases.  The pair consists of  a	list  of
	    alternating  patterns  and	corresponding  replacements, enclosed in
	    parens and quoted so that it forms a single  argument  word  in  the
	    _arguments call.

	    For  example,  some  configure-script  help output describes options
	    only as `--enable-foo', but the script also accepts the negated form
	    `--disable-foo'.  To allow completion of the second form:

		   _arguments -- -s "((#s)--enable- --disable-)"

	    Miscellaneous notes

	    Finally, note that _arguments generally expects to	be  the  primary
	    function  handling any completion for which it is used.  It may have
	    side effects which change the treatment  of  any  matches  added  by
	    other  functions  called after it.	To combine _arguments with other
	    functions, those functions should be  called  either  before  _argu-
	    ments,  as an action within a spec, or in handlers for `->state' ac-
	    tions.

	    Here is a more general example of the use of _arguments:

		   _arguments '-l+:left border:' \
			      '-format:paper size:(letter A4)' \
			      '*-copy:output file:_files::resolution:(300 600)' \
			      ':postscript file:_files -g \*.\(ps\|eps\)' \
			      '*:page number:'

	    This describes three options: `-l',  `-format',  and  `-copy'.   The
	    first  takes  one  argument  described as `left border' for which no
	    completion will be offered because of the empty action.   Its  argu-
	    ment may come directly after the `-l' or it may be given as the next
	    word on the line.

	    The  `-format' option takes one argument in the next word, described
	    as `paper size' for which only the strings `letter' and `A4' will be
	    completed.

	    The `-copy' option may appear more than once on the command line and
	    takes two arguments.  The first is mandatory and will  be  completed
	    as	a filename.  The second is optional (because of the second colon
	    before the description `resolution') and will be completed from  the
	    strings `300' and `600'.

	    The last two descriptions say what should be completed as arguments.
	    The  first	describes  the first argument as a `postscript file' and
	    makes files ending in `ps' or `eps' be completed.  The last descrip-
	    tion gives all other arguments the	description  `page  number'  but
	    does not offer completions.

     _as_if command [arg ... ]
	    This  function  is useful when one command should be completed as if
	    it were another command with particular arguments.	For  example  to
	    complete foo as if it were bar --baz, use

		   compdef '_as_if bar --baz' foo

     _cache_invalid cache_identifier
	    This  function  returns  status zero if the completions cache corre-
	    sponding to the given cache identifier needs rebuilding.  It  deter-
	    mines this by looking up the cache-policy style for the current con-
	    text.   This  should  provide  a function name which is run with the
	    full path to the relevant cache file as the only argument.

	    Example:

		   _example_caching_policy () {
		       # rebuild if cache is more than a week old
		       local -a oldp
		       oldp=( "$1"(Nm+7) )
		       (( $#oldp ))
		   }

     _call_function return name [ arg ... ]
	    If a function name exists, it is called  with  the	arguments  args.
	    The  return  argument gives the name of a parameter in which the re-
	    turn status from the function name should be stored;  if  return  is
	    empty or a single hyphen it is ignored.

	    The  return  status of _call_function itself is zero if the function
	    name exists and was called and non-zero otherwise.

     _call_program [ -l ] [ -p ] tag string ...
	    This function provides a mechanism for the user to override the  use
	    of an external command.  It looks up the command style with the sup-
	    plied tag.	If the style is set, its value is used as the command to
	    execute.   The  strings  from the call to _call_program, or from the
	    style if set, are concatenated with spaces between them and the  re-
	    sulting string is evaluated.  The return status is the return status
	    of the command called.

	    By	default,  the command is run in an environment where all the lo-
	    cale categories (except for LC_CTYPE) are reset to	`C'  by  calling
	    the utility function _comp_locale (see below). If the option `-l' is
	    given, the command is run with the current locale.

	    If	the option `-p' is supplied it indicates that the command output
	    is influenced by the permissions it is run with. If the  gain-privi-
	    leges  style is set to true, _call_program will make use of commands
	    such as sudo, if present on the command-line, to match  the  permis-
	    sions  to  whatever  the  final command is likely to run under. When
	    looking up the gain-privileges and command styles, the command  com-
	    ponent of the zstyle context will end with a slash (`/') followed by
	    the command that would be used to gain privileges.

     _combination [ -s pattern ] tag style spec ... field opts ...
	    This function is used to complete combinations of values,  for exam-
	    ple  pairs of hostnames and usernames.  The style argument gives the
	    style which defines the pairs; it is looked up in a context with the
	    tag specified.

	    The style name consists of field names separated by hyphens, for ex-
	    ample `users-hosts-ports'.	For each field for a  value  is  already
	    known, a spec of the form `field=pattern' is given.  For example, if
	    the  command  line	so  far  specifies  a  user  `pws', the argument
	    `users=pws' should appear.

	    The next argument with no equals sign is taken as the  name  of  the
	    field  for which completions should be generated (presumably not one
	    of the fields for which the value is known).

	    The matches generated will be taken from the  value  of  the  style.
	    These should contain the possible values for the combinations in the
	    appropriate  order	(users, hosts, ports in the example above).  The
	    values for the different fields are separated by colons.   This  can
	    be altered with the option -s to _combination which specifies a pat-
	    tern.   Typically  this  is  a  character  class, as for example `-s
	    "[:@]"' in the case of the users-hosts  style.     Each  `field=pat-
	    tern'  specification  restricts  the completions which apply to ele-
	    ments of the style with appropriately matching fields.

	    If no style with the given name is defined for the given tag, or  if
	    none  of  the strings in style's value match, but a function name of
	    the required field preceded by an underscore is defined, that  func-
	    tion  will be called to generate the matches.  For example, if there
	    is no `users-hosts-ports' or no matching hostname when a host is re-
	    quired, the function `_hosts' will automatically be called.

	    If the same name is used for  more	than  one  field,  in  both  the
	    `field=pattern' and the argument that gives the name of the field to
	    be	completed,  the  number  of the field (starting with one) may be
	    given after the fieldname, separated from it by a colon.

	    All arguments after the required field name are  passed  to  compadd
	    when  generating  matches  from the style value, or to the functions
	    for the fields if they are called.

     _command_names [ -e | - ]
	    This function completes words that are valid  at  command  position:
	    names  of  aliases, builtins, hashed commands, functions, and so on.
	    With the -e flag, only hashed commands are completed.  The - flag is
	    ignored.

     _comp_locale
	    This function resets all the locale categories other  than	LC_CTYPE
	    to	`C' so that the output from external commands can be easily ana-
	    lyzed by the completion system. LC_CTYPE retains the  current  value
	    (taking LC_ALL and LANG into account), ensuring that non-ASCII char-
	    acters in file names are still handled properly.

	    This function should normally be run only in a subshell, because the
	    new  locale  is  exported to the environment. Typical usage would be
	    `$(_comp_locale; command ...)'.

     _completers [ -p ]
	    This function completes names of completers.

	    -p	   Include the leading underscore (`_') in the matches.

     _default
	    This function corresponds to the -default- special context which  is
	    applied where no completion is defined.  It is useful to call it un-
	    der  certain  error  conditions such as completion after an unrecog-
	    nised subcommand.  This applies the concept of graceful  degradation
	    to	the  completion system, allowing it to fallback on basic comple-
	    tion of commonly useful things like filenames.

     _describe [-12JVx] [ -oO | -t tag ] descr name1 [ name2 ] [ opt ... ]
	       [ -- name1 [ name2 ] [ opt ... ] ... ]
	    This function associates completions  with	descriptions.	Multiple
	    groups  separated  by -- can be supplied, potentially with different
	    completion options opts.

	    The descr is taken as a string to display above the matches  if  the
	    format style for the descriptions tag is set.

	    This  is followed by one or two names of arrays.  Alternatively, the
	    arrays may be given inline, following the rules described below, us-
	    ing the syntax (item ...).	(There is no separate  ((...))	form  as
	    with _arguments.)

	    The  array	name1  contains the possible completions with their (op-
	    tional) descriptions in the form `completion:description'.	Any lit-
	    eral colons in completion must be quoted with  a  backslash.   If  a
	    name2 is given, it should have the same number of elements as name1;
	    in	this  case the corresponding elements are added as possible com-
	    pletions instead of the completion strings from name1.  The  comple-
	    tion list will retain the descriptions from name1.

	    Finally, a set of options to pass to compadd can appear.

	    If	the  option  `-o' appears before the first argument, the matches
	    added will be treated as names of command options  (N.B.  not  shell
	    options),  typically  following  a	`-',  `--' or `+' on the command
	    line.  In this case _describe uses the prefix-hidden,  prefix-needed
	    and  verbose  styles  to  find out if the strings should be added as
	    completions and if the descriptions should be  shown.   Without  the
	    `-o'  option,  only the verbose style is used to decide how descrip-
	    tions are shown.  If `-O' is used instead of `-o',	command  options
	    are  completed  as	above  but  _describe  will  not handle the pre-
	    fix-needed style.

	    With the -t option a tag can be specified.	The default is	`values'
	    or, if the -o option is given, `options'.

	    The options -1, -2, -J, -V, -x are passed to _next_label.

	    If	selected  by  the  list-grouped style, strings with the same de-
	    scription will appear together in the list.

	    _describe uses the _all_labels function to generate the matches,  so
	    it does not need to appear inside a loop over tag labels.

     _description [ -x ] [ -12VJ ] tag name descr [ spec ... ]
	    This  function  is	not  to be confused with the previous one; it is
	    used as a helper function for creating options to  compadd.   It  is
	    buried  inside  many of the higher level completion functions and so
	    often does not need to be called directly.

	    The styles listed below are tested in the current context using  the
	    given tag.	The resulting options for compadd are put into the array
	    named name (this is traditionally `expl', but this convention is not
	    enforced).	 The description for the corresponding set of matches is
	    passed to the function in descr.

	    The styles tested are: format,  hidden,  matcher,  ignore-line,  ig-
	    nored-patterns,  group-name  and  sort.   The  format style is first
	    tested for the given tag and then for the  descriptions  tag  if  no
	    value  was	found,	while  the remainder are only tested for the tag
	    given as the first argument.  The function also calls  _setup  which
	    tests some more styles.

	    The string returned by the format style (if any) will be modified so
	    that  the  sequence `%d' is replaced by the descr given as the third
	    argument without any leading or trailing white space.  If, after re-
	    moving the white space, the descr is the empty  string,  the  format
	    style  will not be used and the options put into the name array will
	    not contain an explanation string to be displayed above the matches.

	    If _description is called with more than three arguments, the  addi-
	    tional  specs should be of the form `char:str'.  These supply escape
	    sequence replacements for the  format  style:  every  appearance  of
	    `%char'  will  be  replaced  by  string.  If no additional specs are
	    given but the description in descr conforms to a  common  form  then
	    further  escape  sequences are set for elements of that description.
	    These elements correspond to  a  default  value  (`%o'),  the  units
	    (`%m')  range  of acceptable values (`%r') and the remaining initial
	    part of the description (`%h').  The form the description takes con-
	    sists of specifying the units and range in parentheses and	the  de-
	    fault value in square brackets, for example:

		   _description times expl 'timeout (seconds) (0-60) [20]'

	    It	is  possible to use zformat conditional expressions when styling
	    these elements. So, for example, to add `default:' as a tag but only
	    when there is a default value to show, the format  style  might  in-
	    clude `%(o.default: %o.)'.

	    If the -x option is given, the description will be passed to compadd
	    using  the -x option instead of the default -X.  This means that the
	    description will be displayed even if  there  are  no  corresponding
	    matches.

	    The  options placed in the array name take account of the group-name
	    style, so matches are placed in a separate	group  where  necessary.
	    The group normally has its elements sorted (by passing the option -J
	    to	compadd),  but	if  an option starting with `-V', `-J', `-1', or
	    `-2' is passed to _description, that option will be included in  the
	    array.  Hence it is possible for the completion group to be unsorted
	    by giving the option `-V', `-1V', or `-2V'.

	    In most cases, the function will be used like this:

		   local expl
		   _description files expl file
		   compadd "$expl[@]" - "$files[@]"

	    Note  the  use  of	the  parameter expl, the hyphen, and the list of
	    matches.  Almost all calls to compadd within the  completion  system
	    use  a  similar  format; this ensures that user-specified styles are
	    correctly passed down to the builtins which implement the  internals
	    of completion.

     _dir_list [ -s sep ] [ -S ]
	    Complete  a  list  of  directory names separated by colons (the same
	    format as $PATH).

	    -s sep
		   Use sep as separator between items.	sep defaults to a  colon
		   (`:').

	    -S	   Add sep instead of slash (`/') as an autoremoveable suffix.

     _dispatch context string ...
	    This  sets	the  current context to context and looks for completion
	    functions to handle this context by hunting through the list of com-
	    mand names or special contexts  (as  described  above  for	compdef)
	    given  as  strings.  The first completion function to be defined for
	    one of the contexts in the list is used to generate matches.   Typi-
	    cally,  the  last  string is -default- to cause the function for de-
	    fault completion to be used as a fallback.

	    The function sets the parameter $service to the string being  tried,
	    and  sets  the context/command field (the fourth) of the $curcontext
	    parameter to the context given as the first argument.

     _email_addresses [ -c ] [ -n plugin ]
	    Complete email addresses.  Addresses are provided by plugins.

	    -c	   Complete bare localhost@domain.tld addresses, without a  name
		   part  or  a	comment.  Without this option, RFC822 `Firstname
		   Lastname <address>' strings are completed.

	    -n plugin
		   Complete aliases from plugin.

	    The following plugins are available by default: _email-ldap (see the
	    filter  style),  _email-local  (completes  user@hostname  Unix   ad-
	    dresses),	 _email-mail   (completes   aliases   from   ~/.mailrc),
	    _email-mush, _email-mutt, and _email-pine.

	    Addresses from  the  _email-foo  plugin  are  added  under	the  tag
	    `email-foo'.

	    Writing plugins

	    Plugins  are  written as separate functions with names starting with
	    `_email-'.	They are invoked with the -c option and compadd options.
	    They should either do their own completion or set the  $reply  array
	    to	a  list of `alias:address' elements and return 300.  New plugins
	    will be picked up and run automatically.

     _files
	    The function _files is a wrapper around _path_files. It supports all
	    of the same functionality, with some enhancements -- notably, it re-
	    spects the list-dirs-first style, and it allows  users  to	override
	    the behaviour of the -g and -/ options with the file-patterns style.
	    _files should therefore be preferred over _path_files in most cases.

	    This   function   accepts	the  full  set	of  options  allowed  by
	    _path_files, described below.

     _gnu_generic
	    This function is a simple wrapper around the _arguments function de-
	    scribed above.  It can be used to determine automatically  the  long
	    options  understood  by commands that produce a list when passed the
	    option `--help'.  It is intended to be used as a  top-level  comple-
	    tion  function in its own right.  For example, to enable option com-
	    pletion for the commands foo and bar, use

		   compdef _gnu_generic foo bar

	    after the call to compinit.

	    The completion system as supplied is conservative in its use of this
	    function, since it is important to be sure the  command  understands
	    the option `--help'.

     _guard [ options ] pattern descr
	    This  function  displays  descr  if pattern matches the string to be
	    completed.	It is intended to be used in the action for the specifi-
	    cations passed to _arguments and similar functions.

	    The return status is zero if the message was displayed and the  word
	    to complete is not empty, and non-zero otherwise.

	    The pattern may be preceded by any of the options understood by com-
	    padd  that are passed down from _description, namely -M, -J, -V, -1,
	    -2, -n, -F and -X.	All of these options will be ignored.  This fits
	    in conveniently with the argument-passing conventions of actions for
	    _arguments.

	    As an example, consider a command taking the options -n  and  -none,
	    where  -n  must be followed by a numeric value in the same word.  By
	    using:

		   _arguments '-n-: :_guard "[0-9]#" "numeric value"' '-none'

	    _arguments can be made to both display the message	`numeric  value'
	    and  complete  options after `-n<TAB>'.  If the `-n' is already fol-
	    lowed by one or more digits (the pattern passed to _guard) only  the
	    message  will be displayed; if the `-n' is followed by another char-
	    acter, only options are completed.

     _message [ -r12 ] [ -VJ group ] descr
     _message -e [ tag ] descr
	    The descr is used in the same way as the third argument to the  _de-
	    scription  function, except that the resulting string will always be
	    shown whether or not matches were generated.   This  is  useful  for
	    displaying a help message in places where no completions can be gen-
	    erated.

	    The  format  style	is examined with the messages tag to find a mes-
	    sage; the usual tag, descriptions, is used only if the style is  not
	    set with the former.

	    If the -r option is given, no style is used; the descr is taken lit-
	    erally as the string to display.  This is most useful when the descr
	    comes  from  a pre-processed argument list which already contains an
	    expanded description.  Note that this option does  not  disable  the
	    `%'-sequence parsing done by compadd.

	    The  -12VJ options and the group are passed to compadd and hence de-
	    termine the group the message string is added to.

	    The second -e form gives a description for completions with the  tag
	    tag  to  be  shown	even if there are no matches for that tag.  This
	    form is called by _arguments in the event that there  is  no  action
	    for  an  option specification.  The tag can be omitted and if so the
	    tag is taken from the parameter $curtag; this is maintained  by  the
	    completion system and so is usually correct.  Note that if there are
	    no matches at the time this function is called, compstate[insert] is
	    cleared,  so  additional matches generated later are not inserted on
	    the command line.

     _multi_parts [ -i ] sep array
	    The argument sep is a separator character.	The array may be  either
	    the  name of an array parameter or a literal array in the form `(foo
	    bar)', a parenthesised list of words separated by  whitespace.   The
	    possible  completions are the strings from the array.  However, each
	    chunk delimited by sep will be completed separately.   For	example,
	    the  _tar  function uses `_multi_parts / patharray' to complete par-
	    tial file paths from the given array of complete file paths.

	    The -i option causes _multi_parts to insert a unique match	even  if
	    that  requires multiple separators to be inserted.	This is not usu-
	    ally the expected behaviour with filenames, but certain other  types
	    of	completion, for example those with a fixed set of possibilities,
	    may be more suited to this form.

	    Like other utility functions, this function accepts the `-V',  `-J',
	    `-1', `-2', `-n', `-f', `-X', `-M', `-P', `-S', `-r', `-R', and `-q'
	    options and passes them to the compadd builtin.

     _next_label [ -x ] [ -12VJ ] tag name descr [ option ... ]
	    This  function  is used to implement the loop over different tag la-
	    bels for a particular tag  as  described  above  for  the  tag-order
	    style.   On each call it checks to see if there are any more tag la-
	    bels; if there is it returns status zero,  otherwise  non-zero.   As
	    this  function requires a current tag to be set, it must always fol-
	    low a call to _tags or _requested.

	    The -x12VJ options and the first three arguments are passed  to  the
	    _description  function.   Where appropriate the tag will be replaced
	    by a tag label in this call.  Any description given in the tag-order
	    style is preferred to the descr passed to _next_label.

	    The options given after the descr are set in the parameter given  by
	    name,  and hence are to be passed to compadd or whatever function is
	    called to add the matches.

	    Here is a typical use of this function for the tag foo.  The call to
	    _requested determines if tag foo is required at all; the  loop  over
	    _next_label  handles any labels defined for the tag in the tag-order
	    style.

		   local expl ret=1
		   ...
		   if _requested foo; then
		     ...
		     while _next_label foo expl '...'; do
		       compadd "$expl[@]" ... && ret=0
		     done
		     ...
		   fi
		   return ret

     _normal [ -P | -p precommand ]
	    This is the standard function called to  handle  completion  outside
	    any  special  -context-.   It is called both to complete the command
	    word and also the arguments for a  command.   In  the  second  case,
	    _normal  looks  for  a  special  completion for that command, and if
	    there is none it uses the completion for the -default- context.

	    A second use is to reexamine  the  command	line  specified  by  the
	    $words  array and the $CURRENT parameter after those have been modi-
	    fied.  For example, the function _precommand, which completes  after
	    precommand specifiers such as nohup, removes the first word from the
	    words  array,  decrements the CURRENT parameter, then calls `_normal
	    -p $service'.  The effect is that `nohup cmd ...' is treated in  the
	    same way as `cmd ...'.

	    -P	   Reset  the list of precommands. This option should be used if
		   completing a command  line  which  allows  internal	commands
		   (e.g. builtins and functions) regardless of prior precommands
		   (e.g. `zsh -c').

	    -p precommand
		   Append  precommand  to  the	list of precommands. This option
		   should be used in nearly all cases in which -P is not applic-
		   able.

	    If the command name matches one of the patterns given by one of  the
	    options  -p  or -P to compdef, the corresponding completion function
	    is called and then the parameter _compskip is checked.  If it is set
	    completion is terminated at that point even if no matches have  been
	    found.  This is the same effect as in the -first- context.

     _numbers [ option ... ] [ description ] [ suffix ... ]
	    This  can be used where a number is followed by a suffix to indicate
	    the units.	The unit suffixes are completed and can also be included
	    in the description used when completion is invoked for the preceding
	    number.

	    In addition to common compadd options, _numbers accepts the  follow-
	    ing options:

	    -t tag
		   Specify a tag to use instead of the default of numbers.

	    -u units
		   Indicate the default units for the number, e.g. bytes.

	    -l min
		   Specify the lowest possible value for the number.

	    -m max
		   Specify the highest possible value for the number.

	    -d default
		   Specify the default value.

	    -N	   Allow  negative  numbers.   This  is implied if the range in-
		   cludes a negative.

	    -f	   Allow decimal numbers.

	    Where a particular suffix represents the default units for a number,
	    it should be prefixed with a colon.  Additionally, suffixes  can  be
	    followed  by a colon and a description.  So for example, the follow-
	    ing allows the age of something to be specified, either  in  seconds
	    or with an optional suffix with a longer unit of time:

		   _numbers -u seconds age :s:seconds m:minutes h:hours d:days

	    It is typically helpful for units to be presented in order of magni-
	    tude  when	completed.   To facilitate this, the order in which they
	    are given is preserved.

	    When the format style is looked up with the descriptions tag or  the
	    tag  specified  with -t, the list of suffixes is available as a `%x'
	    escape sequence. This is in addition to the  usual	sequences  docu-
	    mented  under the format style. The form this list takes can also be
	    configured. To this end, the format style is first	looked	up  with
	    the  tag unit-suffixes. The retrieved format is applied to each suf-
	    fix in turn and the results are then concatenated to form  the  com-
	    pleted list. For the unit-suffixes format, `%x' expands to the indi-
	    vidual  suffix  and `%X' to its description. %d' indicates a default
	    suffix and can be used in a condition. The index and  reverse  index
	    are  set  in  `%i' and `%r' respectively and are useful for text in-
	    cluded only with the first and last suffixes in the list. So for ex-
	    ample, the following joins the suffixes together  as  a  comma-sepa-
	    rated list:

		   zstyle ':completion:*:unit-suffixes' format '%x%(r::,)'

     _options
	    This  can  be  used to complete the names of shell options.  It pro-
	    vides a matcher specification that ignores a leading  `no',  ignores
	    underscores  and allows upper-case letters to match their lower-case
	    counterparts (for example, `glob', `noglob', `NO_GLOB' are all  com-
	    pleted).  Any arguments are propagated to the compadd builtin.

     _options_set and _options_unset
	    These  functions  complete	only set or unset options, with the same
	    matching specification used in the _options function.

	    Note that you need to uncomment a few lines  in  the  _main_complete
	    function  for  these functions to work properly.  The lines in ques-
	    tion are used to store the option settings in effect before the com-
	    pletion widget locally sets the options it needs.  Hence these func-
	    tions are not generally used by the completion system.

     _parameters
	    This is used to complete the names of shell parameters.

	    The option `-g pattern' limits the completion  to  parameters  whose
	    type  matches the pattern.	The type of a parameter is that shown by
	    `print ${(t)param}', hence judicious use of `*' in pattern is proba-
	    bly necessary.

	    All other arguments are passed to the compadd builtin.

     _path_files
	    This function is used throughout the completion system  to	complete
	    filenames.	It allows completion of partial paths.	For example, the
	    string `/u/i/s/sig' may be completed to `/usr/include/sys/signal.h'.

	    The options accepted by both _path_files and _files are:

	    -f	   Complete all filenames.  This is the default.

	    -/	   Specifies that only directories should be completed.

	    -g pattern
		   Specifies that only files matching the pattern should be com-
		   pleted.

	    -W paths
		   Specifies  path  prefixes  that  are  to  be prepended to the
		   string from the command line to generate  the  filenames  but
		   that  should not be inserted as completions nor shown in com-
		   pletion listings.  Here, paths may be the name  of  an  array
		   parameter, a literal list of paths enclosed in parentheses or
		   an absolute pathname.

	    -F ignored-files
		   This  behaves  as for the corresponding option to the compadd
		   builtin.  It gives direct control over which filenames should
		   be ignored.	If the option is not present,  the  ignored-pat-
		   terns style is used.

	    Both  _path_files and _files also accept the following options which
	    are passed to compadd: `-J', `-V', `-1',  `-2',  `-n',  `-X',  `-M',
	    `-P', `-S', `-q', `-r', and `-R'.

	    Finally,  the  _path_files function  uses the styles expand, ambigu-
	    ous, special-dirs, list-suffixes and file-sort described above.

     _pick_variant [ -b builtin-label ] [ -c command ] [ -r name ]
		   label=pattern ... label [ arg ... ]
	    This function is used to resolve situations where a  single  command
	    name  requires more than one type of handling, either because it has
	    more than one variant or because there is a name clash  between  two
	    different commands.

	    The  command  to  run  is  taken from the first element of the array
	    words unless this is overridden by the option -c.  This  command  is
	    run and its output is compared with a series of patterns.  Arguments
	    to	be  passed  to the command can be specified at the end after all
	    the other arguments.  The patterns to try in order are given by  the
	    arguments label=pattern; if the output of `command arg ...' contains
	    pattern,  then  label is selected as the label for the command vari-
	    ant.  If none of the patterns match, the final command label is  se-
	    lected and status 1 is returned.

	    If	the `-b builtin-label' is given, the command is tested to see if
	    it is provided as a shell builtin, possibly autoloaded; if	so,  the
	    label builtin-label is selected as the label for the variant.

	    If the `-r name' is given, the label picked is stored in the parame-
	    ter named name.

	    The  results  are  also cached in the _cmd_variant associative array
	    indexed by the name of the command run.

     _regex_arguments name spec ...
	    This function generates a completion function name which matches the
	    specifications specs, a set of regular expressions as described  be-
	    low.   After  running  _regex_arguments, the function name should be
	    called as a normal completion function.  The pattern to  be  matched
	    is given by the contents of the words array up to the current cursor
	    position  joined  together with null characters; no quotation is ap-
	    plied.

	    The arguments are grouped as sets of alternatives separated by  `|',
	    which  are tried one after the other until one matches.  Each alter-
	    native consists of a one or more specifications which are tried left
	    to right, with each pattern matched being stripped in turn from  the
	    command  line being tested, until all of the group succeeds or until
	    one fails; in the latter case, the next alternative is tried.   This
	    structure  can  be repeated to arbitrary depth by using parentheses;
	    matching proceeds from inside to outside.

	    A special procedure is applied if no test succeeds but the remaining
	    command line string contains no null character (implying the remain-
	    ing word is the one for which completions are to be generated).  The
	    completion target is restricted to the remaining word  and	any  ac-
	    tions  for	the  corresponding patterns are executed.  In this case,
	    nothing is stripped from the command  line	string.   The  order  of
	    evaluation	of the actions can be determined by the tag-order style;
	    the various formats supported by _alternative can be used in action.
	    The descr is used for setting up the array parameter expl.

	    Specification arguments  take  one	of  following  forms,  in  which
	    metacharacters such as `(', `)', `#' and `|' should be quoted.

	    /pattern/ [%lookahead%] [-guard] [:tag:descr:action]
		   This  is  a	single	primitive component.  The function tests
		   whether the	combined  pattern  `(#b)((#B)pattern)lookahead*'
		   matches the command line string.  If so, `guard' is evaluated
		   and	its  return  status is examined to determine if the test
		   has succeeded.  The pattern string `[]' is  guaranteed  never
		   to  match.	The  lookahead	is not stripped from the command
		   line before the next pattern is examined.

		   The argument starting with : is used in the same manner as an
		   argument to _alternative.

		   A component is used as follows: pattern is tested to  see  if
		   the	component  already  exists  on	the command line.  If it
		   does, any following specifications are examined to find some-
		   thing to complete.  If a component is  reached  but	no  such
		   pattern exists yet on the command line, the string containing
		   the	action	is  used  to  generate matches to insert at that
		   point.

	    /pattern/+ [%lookahead%] [-guard] [:tag:descr:action]
		   This is similar to `/pattern/ ...' but the left part  of  the
		   command  line string (i.e. the part already matched by previ-
		   ous patterns) is also considered part of the completion  tar-
		   get.

	    /pattern/- [%lookahead%] [-guard] [:tag:descr:action]
		   This  is  similar  to  `/pattern/ ...' but the actions of the
		   current and previously matched patterns are ignored	even  if
		   the following `pattern' matches the empty string.

	    ( spec )
		   Parentheses	may be used to groups specs; note each parenthe-
		   sis is a single argument to _regex_arguments.

	    spec #
		   This allows any number of repetitions of spec.

	    spec spec
		   The two specs are to be matched one after the  other  as  de-
		   scribed above.

	    spec | spec
		   Either of the two specs can be matched.

	    The function _regex_words can be used as a helper function to gener-
	    ate  matches  for a set of alternative words possibly with their own
	    arguments as a command line argument.

	    Examples:

		   _regex_arguments _tst /$'[^\0]#\0'/ \
		       /$'[^\0]#\0'/ :'compadd aaa'

	    This generates a function _tst that completes aaa as its only  argu-
	    ment.   The tag and description for the action have been omitted for
	    brevity (this works but is not  recommended  in  normal  use).   The
	    first  component  matches  the command word, which is arbitrary; the
	    second matches  any argument.  As the argument  is	also  arbitrary,
	    any following component would not depend on aaa being present.

		   _regex_arguments _tst /$'[^\0]#\0'/ \
		       /$'aaa\0'/ :'compadd aaa'

	    This  is  a  more typical use; it is similar, but any following pat-
	    terns would only match if aaa was present as the first argument.

		   _regex_arguments _tst /$'[^\0]#\0'/ \( \
		       /$'aaa\0'/ :'compadd aaa' \
		       /$'bbb\0'/ :'compadd bbb' \) \#

	    In this example, an indefinite number of command  arguments  may  be
	    completed.	Odd arguments are completed as aaa and even arguments as
	    bbb.   Completion  fails unless the set of aaa and bbb arguments be-
	    fore the current one is matched correctly.

		   _regex_arguments _tst /$'[^\0]#\0'/ \
		       \( /$'aaa\0'/ :'compadd aaa' \| \
		       /$'bbb\0'/ :'compadd bbb' \) \#

	    This is similar, but either aaa or bbb may be completed for any  ar-
	    gument.  In this case _regex_words could be used to generate a suit-
	    able expression for the arguments.

     _regex_words tag description spec ...
	    This function can be used to generate arguments for the _regex_argu-
	    ments  command  which  may	be  inserted at any point where a set of
	    rules is expected.	The tag and description give a standard tag  and
	    description  pertaining  to the current context.  Each spec contains
	    two or three arguments separated by a colon: note that there  is  no
	    leading colon in this case.

	    Each  spec gives one of a set of words that may be completed at this
	    point, together with arguments.  It is thus  roughly  equivalent  to
	    the _arguments function when used in normal (non-regex) completion.

	    The  part  of the spec before the first colon is the word to be com-
	    pleted.  This may contain a *; the entire word, before and after the
	    * is completed, but only the text before the * is required	for  the
	    context  to  be  matched, so that further arguments may be completed
	    after the abbreviated form.

	    The second part of spec is a description for  the  word  being  com-
	    pleted.

	    The  optional  third  part of the spec describes how words following
	    the one being completed are themselves to be completed.  It will  be
	    evaluated  in order to avoid problems with quoting.  This means that
	    typically it contains a reference to an array containing  previously
	    generated regex arguments.

	    The  option  -t  term specifies a terminator for the word instead of
	    the usual space.  This is handled as an auto-removable suffix in the
	    manner of the option -s sep to _values.

	    The result of the processing by _regex_words is placed in the  array
	    reply,  which  should be made local to the calling function.  If the
	    set of words and arguments may be matched repeatedly, a # should  be
	    appended to the generated array at that point.

	    For example:

		   local -a reply
		   _regex_words mydb-commands 'mydb commands' \
		     'add:add an entry to mydb:$mydb_add_cmds' \
		     'show:show entries in mydb'
		   _regex_arguments _mydb "$reply[@]"
		   _mydb "$@"

	    This  shows a completion function for a command mydb which takes two
	    command arguments, add and show.  show takes no arguments, while the
	    arguments  for  add  have  already	been  prepared	 in   an   array
	    mydb_add_cmds, quite possibly by a previous call to _regex_words.

     _requested [ -x ] [ -12VJ ] tag [ name descr [ command [ arg ... ] ]
	    This  function  is called to decide whether a tag already registered
	    by a call to _tags (see below) has been requested by  the  user  and
	    hence completion should be performed for it.  It returns status zero
	    if	the  tag  is  requested and non-zero otherwise.  The function is
	    typically used as part of a loop over different tags as follows:

		   _tags foo bar baz
		   while _tags; do
		     if _requested foo; then
		       ... # perform completion for foo
		     fi
		     ... # test the tags bar and baz in the same way
		     ... # exit loop if matches were generated
		   done

	    Note that the test for whether matches were generated  is  not  per-
	    formed  until  the	end of the _tags loop.	This is so that the user
	    can set the tag-order style to specify a set of tags to be completed
	    at the same time.

	    If name and descr are given, _requested calls the _description func-
	    tion with these arguments together with the options passed	to  _re-
	    quested.

	    If command is given, the _all_labels function will be called immedi-
	    ately with the same arguments.  In simple cases this makes it possi-
	    ble to perform the test for the tag and the matching in one go.  For
	    example:

		   local expl ret=1
		   _tags foo bar baz
		   while _tags; do
		     _requested foo expl 'description' \
			 compadd foobar foobaz && ret=0
		     ...
		     (( ret )) || break
		   done

	    If	the  command is not compadd, it must nevertheless be prepared to
	    handle the same options.

     _retrieve_cache cache_identifier
	    This function retrieves completion information from the  file  given
	    by	 cache_identifier,  stored  in	a  directory  specified  by  the
	    cache-path style which defaults to ~/.zcompcache.  The return status
	    is zero if retrieval was successful.  It will only attempt retrieval
	    if the use-cache style is set, so you can call this function without
	    worrying about whether the user wanted to use the caching layer.

	    See _store_cache below for more details.

     _sep_parts
	    This function is passed alternating arrays and separators  as  argu-
	    ments.   The  arrays  specify completions for parts of strings to be
	    separated by the separators.  The arrays may be the names  of  array
	    parameters	or  a quoted list of words in parentheses.  For example,
	    with the array `hosts=(ftp news)' the call `_sep_parts '(foo bar)' @
	    hosts' will complete the string  `f' to `foo' and the  string  `b@n'
	    to `bar@news'.

	    This  function  accepts  the compadd options `-V', `-J', `-1', `-2',
	    `-n', `-X', `-M', `-P', `-S', `-r', `-R', and `-q' and  passes  them
	    on to the compadd builtin used to add the matches.

     _sequence [ -s sep ] [ -n max ] [ -d ] function [ - ] ...
	    This  function  is a wrapper to other functions for completing items
	    in a separated list. The same function is used to complete each item
	    in the list. The separator is specified with the -s option. If -s is
	    omitted it will use `,'. Duplicate values are not matched unless  -d
	    is	specified. If there is a fixed or maximum number of items in the
	    list, this can be specified with the -n option.

	    Common compadd options are passed on to the function. It is possible
	    to use compadd directly with _sequence, though _values may	be  more
	    appropriate in this situation.

     _setup tag [ group ]
	    This  function sets up the special parameters used by the completion
	    system appropriately for the tag given as the  first  argument.   It
	    uses   the	 styles   list-colors,	 list-packed,	list-rows-first,
	    last-prompt, accept-exact, menu and force-list.

	    The optional group supplies the name  of  the  group  in  which  the
	    matches  will be placed.  If it is not given, the tag is used as the
	    group name.

	    This function is called automatically from _description and hence is
	    not normally called explicitly.

     _store_cache cache_identifier param ...
	    This function, together with _retrieve_cache and _cache_invalid, im-
	    plements a caching layer which can be used in any  completion  func-
	    tion.   Data obtained by costly operations are stored in parameters;
	    this function then dumps the values of those parameters to	a  file.
	    The  data  can  then  be  retrieved  quickly from that file via _re-
	    trieve_cache, even in different instances of the shell.

	    The cache_identifier specifies the file which  the	data  should  be
	    dumped  to.   The  file  is  stored  in a directory specified by the
	    cache-path style which defaults  to  ~/.zcompcache.   The  remaining
	    params arguments are the parameters to dump to the file.

	    The  return  status is zero if storage was successful.  The function
	    will only attempt storage if the use-cache style is set, so you  can
	    call this function without worrying about whether the user wanted to
	    use the caching layer.

	    The  completion  function  may avoid calling _retrieve_cache when it
	    already has the completion data available as  parameters.	However,
	    in that case it should call _cache_invalid to check whether the data
	    in the parameters and in the cache are still valid.

	    See  the  _perl_modules  completion function for a simple example of
	    the usage of the caching layer.

     _tags [ [ -C name ] tag ... ]
	    If called with arguments, these are taken to be the  names	of  tags
	    valid for completions in the current context.  These tags are stored
	    internally and sorted by using the tag-order style.

	    Next,  _tags  is  called  repeatedly without arguments from the same
	    completion function.  This successively selects the  first,  second,
	    etc.  set  of tags requested by the user.  The return status is zero
	    if at least one of the tags is requested and non-zero otherwise.  To
	    test if a particular tag is to be  tried,  the  _requested	function
	    should be called (see above).

	    If	`-C  name'  is given, name is temporarily stored in the argument
	    field (the fifth) of the context in the curcontext parameter  during
	    the call to _tags; the field is restored on exit.  This allows _tags
	    to	use  a	more specific context without having to change and reset
	    the curcontext parameter (which has the same effect).

     _tilde_files
	    Like _files, but resolve leading tildes according to  the  rules  of
	    filename  expansion, so the suggested completions don't start with a
	    `~' even if the filename on the command-line does.

     _values [ -O name ] [ -s sep ] [ -S sep ] [ -wC ] desc spec ...
	    This is used to complete arbitrary keywords (values) and their argu-
	    ments, or lists of such combinations.

	    If the first argument is the option `-O name', it will  be	used  in
	    the same way as by the _arguments function.  In other words, the el-
	    ements of the name array will be passed to compadd when executing an
	    action.

	    If	the  first  argument  (or the first argument after `-O name') is
	    `-s', the next argument is used as the character that separates mul-
	    tiple values.  This character  is  automatically  added  after  each
	    value in an auto-removable fashion (see below); all values completed
	    by	`_values -s' appear in the same word on the command line, unlike
	    completion using _arguments.  If this option is not present, only  a
	    single value will be completed per word.

	    Normally,  _values will only use the current word to determine which
	    values are already present on the command line and hence are not  to
	    be	completed again.  If the -w option is given, other arguments are
	    examined as well.

	    The first non-option argument, desc, is used as a string to print as
	    a description before listing the values.

	    All other arguments describe the possible values and their arguments
	    in the same format used for the description of options by the _argu-
	    ments function (see above).  The only differences are that no  minus
	    or	plus sign is required at the beginning, values can have only one
	    argument, and the forms of action beginning with an equal  sign  are
	    not supported.

	    The  character separating a value from its argument can be set using
	    the option -S (like -s, followed by the character to use as the sep-
	    arator in the next argument).  By default the equals  sign	will  be
	    used as the separator between values and arguments.

	    Example:

		   _values -s , 'description' \
			   '*foo[bar]' \
			   '(two)*one[number]:first count:' \
			   'two[another number]::second count:(1 2 3)'

	    This  describes three possible values: `foo', `one', and `two'.  The
	    first is described as `bar', takes no argument and may  appear  more
	    than  once.   The  second  is described as `number', may appear more
	    than once, and takes one  mandatory  argument  described  as  `first
	    count';  no  action  is specified, so it will not be completed.  The
	    `(two)' at the beginning says that if the  value  `one'  is  on  the
	    line,  the	value `two' will no longer be considered a possible com-
	    pletion.  Finally, the last value (`two') is described  as	`another
	    number'  and  takes an optional argument described as `second count'
	    for which the completions (to appear after an `=') are `1', `2', and
	    `3'.  The _values function will complete lists of these values sepa-
	    rated by commas.

	    Like _arguments, this function temporarily adds another context name
	    component to the arguments element (the fifth) of the  current  con-
	    text while executing the action.  Here this name is just the name of
	    the value for which the argument is completed.

	    The style verbose is used to decide if the descriptions for the val-
	    ues (but not those for the arguments) should be printed.

	    The  associative  array  val_args is used to report values and their
	    arguments; this works similarly to the  opt_args  associative  array
	    used  by  _arguments.  Hence the function calling _values should de-
	    clare the local parameters state,  state_descr,  line,  context  and
	    val_args:

		   local context state state_descr line
		   typeset -A val_args

	    when using an action of the form `->string'.  With this function the
	    context  parameter	will be set to the name of the value whose argu-
	    ment is to be completed.  Note  that  for  _values,  the  state  and
	    state_descr  are scalars rather than arrays.  Only a single matching
	    state is returned.

	    Note also that _values normally adds the character used as the sepa-
	    rator between values as an auto-removable suffix (similar to  a  `/'
	    after  a directory).  However, this is not possible for a `->string'
	    action as the matches for the argument are generated by the  calling
	    function.	To get the usual behaviour, the calling function can add
	    the separator x as a suffix by passing the options	`-qS  x'  either
	    directly or indirectly to compadd.

	    The option -C is treated in the same way as it is by _arguments.  In
	    that  case	the parameter curcontext should be made local instead of
	    context (as described above).

     _wanted [ -x ] [ -C name ]  [ -12VJ ] tag name descr command [ arg ...]
	    In many contexts, completion can only generate one particular set of
	    matches, usually corresponding to a  single  tag.	However,  it  is
	    still  necessary to decide whether the user requires matches of this
	    type.  This function is useful in such a case.

	    The arguments to _wanted are the same as those to  _requested,  i.e.
	    arguments  to  be passed to _description.  However, in this case the
	    command is not optional;  all the processing of tags, including  the
	    loop over both tags and tag labels and the generation of matches, is
	    carried out automatically by _wanted.

	    Hence  to  offer  only one tag and immediately add the corresponding
	    matches with the given description:

		   local expl
		   _wanted tag expl 'description' \
		       compadd -- match1 match2...

	    See also the use of _wanted in the example function in  the  subsec-
	    tion `Dynamic named directories' in zshexpn(1).

	    Note that, as for _requested, the command must be able to accept op-
	    tions to be passed down to compadd.

	    Like  _tags this function supports the -C option to give a different
	    name for the argument context field.  The -x  option  has  the  same
	    meaning as for _description.

     _widgets [ -g pattern ]
	    This  function completes names of zle widgets (see the section `Wid-
	    gets' in zshzle(1)).  The pattern, if present,  is	matched  against
	    values  of the $widgets special parameter, documented in the section
	    `The zsh/zleparameter Module' in zshmodules(1).

COMPLETION SYSTEM VARIABLES
     There are some standard variables, initialised by the _main_complete  func-
     tion and then used from other functions.

     The standard variables are:

     _comp_caller_options
	    The  completion  system uses setopt to set a number of options. This
	    allows functions to be written  without  concern  for  compatibility
	    with  every possible combination of user options. However, sometimes
	    completion needs to know what the  user's  option  preferences  are.
	    These  are	saved in the _comp_caller_options associative array. Op-
	    tion names, spelled in lowercase without underscores, are mapped  to
	    one or other of the strings `on' and `off'.

     _comp_priv_prefix
	    Completion functions such as _sudo can set the _comp_priv_prefix ar-
	    ray  to  a	command prefix that may then be used by _call_program to
	    match the privileges when calling programs to generate matches.

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

COMPLETION DIRECTORIES
     In the source distribution, the files are contained in various  subdirecto-
     ries of the Completion directory.	They may have been installed in the same
     structure,  or  into one single function directory.  The following is a de-
     scription of the files found in the original directory structure.	 If  you
     wish to alter an installed file, you will need to copy it to some directory
     which  appears  earlier  in your fpath than the standard directory where it
     appears.

     Base   The core functions	and  special  completion  widgets  automatically
	    bound  to  keys.  You will certainly need most of these, though will
	    probably not need to alter	them.	Many  of  these  are  documented
	    above.

     Zsh    Functions  for  completing	arguments  of shell builtin commands and
	    utility functions for this.  Some of these are also  used  by  func-
	    tions from the Unix directory.

     Unix   Functions  for  completing arguments of external commands and suites
	    of commands.  They may need modifying for your system,  although  in
	    many cases some attempt is made to decide which version of a command
	    is	present.  For example, completion for the mount command tries to
	    determine the system it is running on,  while  completion  for  many
	    other utilities try to decide whether the GNU version of the command
	    is in use, and hence whether the --help option is supported.

     X, AIX, BSD, ...
	    Completion	and utility function for commands available only on some
	    systems.  These are not arranged hierarchically,  so,  for	example,
	    both  the  Linux and Debian directories, as well as the X directory,
	    may be useful on your system.

zsh 5.9.1			  May 31, 2026			   ZSHCOMPSYS(1)

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