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ZSHCOMPSYS(1)									    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 described 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
       o      an  argument or option position: these describe the position on the command line at
	      which completion is requested.  For example `first  argument  to	rmdir,	the  word
	      being completed names a directory';

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

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

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

       Tags  play  a dual role.  They serve as a classification 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 directo-
       ries, so both of these are tags.  They also appear as the rightmost element in  a  context
       specification.

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

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

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

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

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

INITIALIZATION
       If  the	system	was  installed completely, it should be enough to call the shell function
       compinit from your initialization file; see  the  next  section.   However,  the  function
       compinstall can be run by a user to configure various aspects of the completion system.

       Usually,  compinstall  will  insert  code into .zshrc, although if that is not writable it
       will save it in another file and tell you that file's location.	Note that it is up to you
       to  make  sure that the lines added to .zshrc are actually run; you may, for example, need
       to move them to an earlier place in the file if .zshrc usually returns early.  So long  as
       you  keep them all together (including the comment lines at the start and finish), you can
       rerun compinstall and it will correctly locate and modify  these  lines.   Note,  however,
       that  any  code	you add to this section by hand is likely to be lost if you rerun compin-
       stall, although lines using the command `zstyle' should be gracefully handled.

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

       To run compinstall you will need to make sure it is in a directory mentioned in your fpath
       parameter, which should already be the case if zsh was properly configured as long as your
       startup files do not remove the appropriate directories	from  fpath.   Then  it  must  be
       autoloaded (`autoload -U compinstall' is recommended).  You can abort the installation any
       time you are being prompted for information, and your .zshrc will not be altered  at  all;
       changes	only  take place right at the end, where you are specifically asked for confirma-
       tion.

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

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

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

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

       If  the number of completion files changes, compinit will recognise this and produce a new
       dump file.  However, if the name of a function or the arguments in the  first  line  of	a
       #compdef  function  (as	described below) change, it is easiest to delete the dump file by
       hand so that compinit will re-create it the next time it is run.  The check  performed  to
       see  if	there are new functions can be omitted by giving the option -C.  In this case the
       dump file will only be created if there isn't one already.

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

       If the parameter _compdir is set, compinit uses it as a directory where	completion  func-
       tions  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.

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

       The function bashcompinit provides compatibility with bash's programmable completion  sys-
       tem.   When run it will define the functions, compgen and complete which correspond to the
       bash builtins with the same names.  It will then be possible to use completion  specifica-
       tions 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 required directories for the standard functions.

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

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

       The tags are:

       #compdef names... [ -[pP] patterns... [ -N names... ] ]
	      The  file  will  be made autoloadable and the function defined in it will be called
	      when completing names, each of which is either the name of a  command  whose  argu-
	      ments  are to be completed or one of a number of special contexts in the form -con-
	      text- described below.

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

	      If  the #compdef line contains one of the options -p or -P, the words following are
	      taken to be patterns.  The function will be called when completion is attempted for
	      a  command  or context that matches one of the patterns.	The options -p and -P are
	      used to specify patterns to be tried before  or  after  other  completions  respec-
	      tively.  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-sequences...
	      This option creates a widget behaving like the builtin widget style and binds it to
	      the given key-sequences, if any.	The style must be one of the builtin widgets that
	      perform  completion, namely complete-word, delete-char-or-list, expand-or-complete,
	      expand-or-complete-prefix, list-choices, menu-complete, menu-expand-or-complete, or
	      reverse-menu-complete.   If  the	zsh/complist module is loaded (see zshmodules(1))
	      the widget menu-select is also available.

	      When one of the key-sequences is typed, the function in the file will be invoked to
	      generate the matches.  Note that a key will not be re-bound if it already was (that
	      is, was bound to something other than undefined-key).  The widget created  has  the
	      same name as the file and can be bound to any other keys using bindkey as usual.

       #compdef -K widget-name style key-sequences ...
	      This  is similar to -k except that only one key-sequences argument may be given for
	      each widget-name style pair.  However, the entire set of	three  arguments  may  be
	      repeated	with  a  different  set  of  arguments.  Note in particular that the wid-
	      get-name must be distinct in each set.  If it does not begin with `_' this will  be
	      added.   The  widget-name  should  not  clash with the name of any existing widget:
	      names based on the name of the function are most useful.	For example,

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

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

       #autoload [ options ]
	      Functions  with  the #autoload tag are marked for autoloading but are not otherwise
	      treated specially.  Typically they are to be called from within one of the  comple-
	      tion  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 (`foo=(...)')

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

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

       -command-
	      A word in command position

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

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

       -equal-
	      A word beginning with an equals sign

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

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

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

       -redirect-
	      The word after a redirection operator.

       -subscript-
	      The contents of a parameter subscript.

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

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

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

       The  contexts  -redirect-  and  -value- allow extra context-specific information.  (Inter-
       nally, this is handled by the functions for each context calling the function  _dispatch.)
       The extra information is added separated by commas.

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

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

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

       As an example:

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

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

       Also:

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

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

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

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

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

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

       compdef [ -ane ] function names... [ -[pP] patterns... [ -N names... ] ]
       compdef -d names...
       compdef -k [ -an ] function style key-sequences...
       compdef -K [ -an ] function name style key-sequences ...
	      The first form defines the function to call for 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  ser-
	      vice.

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

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

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

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

	      The names may also contain -p, -P and -N options as described for the #compdef tag.
	      The effect on the argument list is identical, switching between definitions of pat-
	      terns 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 pat-
	      tern-functions will be called; if it is set to a	value  containing  the	substring
	      `all', no other function will be called.

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

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

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

       The  function compdef can be used to associate existing completion functions with new com-
       mands.  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 generated.

   Overview
       When completion is attempted somewhere on the command line  the	completion  system  first
       works  out  the	context.   This takes account of a number of things including the command
       word (such as `grep' or `zsh') and options to which the current word may  be  an  argument
       (such as the `-o' option to zsh which takes a shell option as an argument).

       This  context  information  is condensed into a string consisting of multiple fields sepa-
       rated by colons, referred to simply as `the context' in the remainder  of  the  documenta-
       tion.   This is used to look up styles, context-sensitive options that can be used to con-
       figure the completion system.  The context used for lookup may vary during the  same  call
       to the completion system.

       The  context string always consists of a fixed set of fields, separated by colons and with
       a leading colon before the first, in the form :completion:function:completer:command:argu-
       ment:tag.  These have the following meaning:

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

       o      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  wid-
	      gets  such  as  predict-on and the various functions in the Widget directory of the
	      distribution to the name of that function, often in an abbreviated form.

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

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

       o      The  argument; this indicates which command line or option argument we are complet-
	      ing.  For command arguments this generally takes the form argument-n,  where  n  is
	      the  number  of  the  argument,  and for arguments 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 arguments,
	      so many completions do not set this.

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

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

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

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

	      dvips -o ...

       and the completion function will generate filenames.

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

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

       Styles determine such things as how the matches are generated, similarly to shell  options
       but with much more control.  They can have any number of strings as their value.  They are
       defined with the zstyle builtin command (see zshmodules(1)).

       When looking up styles the completion system uses full context names, including	the  tag.
       Looking	up the value of a style therefore consists of two things:  the context, which may
       be matched as a pattern, and the name of the style itself, which must be given exactly.

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

	      zstyle ':completion:*' verbose yes

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

       Many  such  general purpose styles can be configured simply by using the compinstall func-
       tion.

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

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

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

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

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

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

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

       Note that the order in which styles are defined does not matter; the style mechanism  uses
       the  most  specific  possible match for a particular style to determine the set of values.
       More precisely, strings are  preferred  over  patterns  (for  example,  `:completion::com-
       plete:foo'  is more specific than `:completion::complete:*'), and longer patterns are pre-
       ferred over shorter patterns.

       Style names like those of tags are arbitrary and depend on the completion function.   How-
       ever, 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 containing all possible
	      expansions

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

       arguments
	      for arguments to a command

       arrays for names of array parameters

       association-keys
	      for keys of associative arrays; used when completing inside a subscript to a param-
	      eter 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 com-
	      pleting character classes after an opening bracket

       colormapids
	      for X colormap ids

       colors for color names

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

       contexts
	      for contexts in arguments to the zstyle builtin command

       corrections
	      used by the _approximate and _correct completers for possible corrections

       cursors
	      for cursor names used by X programs

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

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

       devices
	      for names of device special files

       directories
	      for names of directories -- local-directories is used instead when completing argu-
	      ments of cd and related builtin commands when the cdpath array is set

       directory-stack
	      for entries in the directory stack

       displays
	      for X display names

       domains
	      for network domains

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

       extensions
	      for X server extensions

       file-descriptors
	      for numbers of open file descriptors

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

       fonts  for X font names

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

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

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

       groups for names of user groups

       history-words
	      for words from the history

       hosts  for hostnames

       indexes
	      for array indexes

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

       interfaces
	      for network interfaces

       keymaps
	      for names of zsh keymaps

       keysyms
	      for names of X keysyms

       libraries
	      for names of system libraries

       limits for system limits

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

       manuals
	      for names of manual pages

       mailboxes
	      for e-mail folders

       maps   for map names (e.g. NIS maps)

       messages
	      used to look up the format style for messages

       modifiers
	      for names of X modifiers

       modules
	      for modules (e.g. zsh modules)

       my-accounts
	      used to look up the users-hosts style

       named-directories
	      for named directories (you wouldn't have guessed that, would you?)

       names  for all kinds of names

       newsgroups
	      for USENET groups

       nicknames
	      for nicknames of NIS maps

       options
	      for command options

       original
	      used  by the _approximate, _correct and _expand completers when offering the origi-
	      nal string as a match

       other-accounts
	      used to look up the users-hosts style

       other-files
	      for the names of any non-directory files.  This is used instead of  all-files  when
	      the list-dirs-first style is in effect.

       packages
	      for packages (e.g. rpm or installed Debian packages)

       parameters
	      for names of parameters

       path-directories
	      for  names of directories found by searching the cdpath array when completing argu-
	      ments of cd and related builtin commands (compare local-directories)

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

       pods   for perl pods (documentation files)

       ports  for communication ports

       prefixes
	      for prefixes (like those of a URL)

       printers
	      for print queue names

       processes
	      for process identifiers

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

       sequences
	      for sequences (e.g. mh sequences)

       sessions
	      for sessions in the zftp function suite

       signals
	      for signal names

       strings
	      for strings (e.g. the replacement strings for the cd builtin command)

       styles for styles used by the zstyle builtin command

       suffixes
	      for filename extensions

       tags   for tags (e.g. rpm tags)

       targets
	      for makefile targets

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

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

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

       users  for usernames

       values for one of a set of values in certain lists

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

       visuals
	      for X visuals

       warnings
	      used to look up the format style for warnings

       widgets
	      for zsh widget names

       windows
	      for IDs of X windows

       zsh-options
	      for shell options

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

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

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

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

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

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

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

	      When this style is true, any prefix of a path that matches an existing directory is
	      accepted without any attempt to complete it further.  Hence, in the given  example,
	      the path /usr/bin/ is accepted immediately and completion tried in that directory.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       completer
	      The strings given as the value of this style provide the	names  of  the	completer
	      functions  to  use.  The available completer functions are described in 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  under-
	      scores  replaced	by  hyphens.   In the second case the function is the name of the
	      completer to call, but the context will contain the user-defined name in	the  com-
	      pleter  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 `func-
	      tions:name' form, because otherwise the context name will be the same in all  calls
	      to  the  completer;  possible  exceptions to this rule are the _ignored and _prefix
	      completers.

	      The default value for this style is `_complete _ignored': only completion  will  be
	      done,  first using the ignored-patterns style and the $fignore array and then with-
	      out ignoring matches.

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

       delimiters
	      This  style  is used when adding a delimiter for use with history modifiers or glob
	      qualifiers that have delimited arguments.  It is an array of  preferred  delimiters
	      to  add.	 Non-special characters are preferred as the completion system may other-
	      wise 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  com-
	      pletion for the target command is invoked.
	      zstyle ':completion:*:sudo::' environ \
		PATH="/sbin:/usr/sbin:$PATH" HOME="/root"

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

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

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

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

	      It is important to use a sufficiently  restrictive  context  when  specifying  fake
	      strings.	 Note  that  the styles fake-files and fake-parameters provide additional
	      features when completing files or parameters.

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

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

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

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

	      This can be useful on systems that support special  file	systems  whose	top-level
	      pathnames  can  not be listed or generated with glob patterns.  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 param-
	      eter (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 con-
	      text.  Names for which no type is specified will always be completed.

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

		     zmodload -i zsh/stat
		     disable stat

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

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

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

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

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

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

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

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

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

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

	      The tag may also be followed by an optional second colon and a  description,  which
	      will be used for the `%d' in the value of the format style (if that is set) instead
	      of the default description supplied by the completion function.  If the description
	      given  here  contains itself a `%d', that is replaced with the description supplied
	      by the completion function.

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

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

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

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

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

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

       file-sort
	      The standard filename completion function uses this style without a tag  to  deter-
	      mine  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  alphabeti-
	      cally  by name.  If the value contains the string `reverse', sorting is done in the
	      opposite order.  If the value contains the string `follow', timestamps are  associ-
	      ated  with  the  targets of symbolic links; the default is to use the timestamps of
	      the links themselves.

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

       force-list
	      This  forces  a list of completions to be shown at any point where listing is done,
	      even in cases where the list would usually be suppressed.   For  example,  normally
	      the  list  is  only  shown if there are at least two different matches.  By setting
	      this style to `always', the list will always be shown, even if there is only a sin-
	      gle  match  that will immediately be accepted.  The style may also be set to a num-
	      ber.  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 cur-
	      rent completion.	Hence the listing can be forced only for certain types of match.

       format If this is set for the descriptions tag, its value is used as a string  to  display
	      above  matches  in  completion  lists.   The  sequence  `%d' in this string will be
	      replaced with a short description of what these matches are.  This string may  also
	      contain  the  following sequences to specify output attributes, as described in the
	      section EXPANSION OF PROMPT SEQUENCES in zshmisc(1): `%B', `%S', `%U',  `%F',  `%K'
	      and  their lower case counterparts, as well as `%{...%}'.  `%F', `%K' and `%{...%}'
	      take arguments in the same form as prompt expansion.  Note that the %G sequence  is
	      not available; an argument to `%{' should be used instead.

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

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

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

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

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

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

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

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

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

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

	      If  the  name given is the empty string the name of the tag for the matches will be
	      used as the name of the group.  So, to have all different  types	of  matches  dis-
	      played separately, one can just set:

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

	      All  matches  for  which	no  group  name  is  defined will be put in a group named
	      -default-.

       group-order
	      This style is additional to the group-name style to specify the order  for  display
	      of the groups defined by that style (compare tag-order, which determines which com-
	      pletions 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 com-
	      mands appear in that order when completing in command position:

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

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

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

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

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

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

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

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

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

       ignore-parents
	      The style is tested without a tag by the function completing pathnames in order  to
	      determine  whether to ignore the names of directories already mentioned in the cur-
	      rent word, or the name of the current working directory.	The  value  must  include
	      one or both of the following strings:

	      parent The name of any directory whose path is already contained in the word on the
		     line is ignored.  For example, when completing after foo/../, the	directory
		     foo will not be considered a valid completion.

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

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

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

	      directory
		     Ignore the specified directories only when names  of  directories	are  com-
		     pleted, not when completing names of files.

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

       extra-verbose
	      If set, the completion listing is more verbose at the cost of a  probable  decrease
	      in  completion  speed.   Completion performance will suffer if this style is set to
	      `true'.

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

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

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

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

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

       insert-tab
	      If this is set to `true', the completion system will insert a TAB character (assum-
	      ing 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', com-
	      pletion will be done even there.

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

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

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

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

	      In  the case of the _match completer, the style may also be set to the string `pat-
	      tern'.  Then the pattern on the line is left unchanged if it does not  match  unam-
	      biguously.

       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  exam-
	      ple,  the  string  `~/f*' would be expanded to `~/foo' instead of `/home/user/foo'.
	      If the style is set to `changed' (the  default),	the  prefix  will  only  be  left
	      unchanged  if  there were other changes between the expanded words and the original
	      word from the command line.  Any other value  forces  the  prefix  to  be  expanded
	      unconditionally.

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

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

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

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

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

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

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

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

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

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

       list-dirs-first
	      This  is	used  by file completion.  If set, directories to be completed are listed
	      separately from and before completion for other files, regardless of tag	ordering.
	      In  addition,  the  tag other-files is used in place of all-files for the remaining
	      files, to indicate that no directories are presented with that tag.

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

       list-packed
	      This is tested for each tag valid in the current context as  well  as  the  default
	      tag.   If  it  is set to `true', the corresponding matches appear in listings as if
	      the LIST_PACKED option were set.	If it is set to `false',  they	are  listed  nor-
	      mally.

       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  zshmod-
	      ules(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 numeric argument, some other) width.

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

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

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

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

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

	      For example:

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

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

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

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

       matcher
	      This  style  is  tested  separately for each tag valid in the current context.  Its
	      value is added to any match specifications given by  the	matcher-list  style.   It
	      should  be  in  the  form described in the section `Completion Matching Control' in
	      zshcompwid(1).

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

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

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

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

	      It is possible to create match specifications valid for  particular  completers  by
	      using the third field of the context.  For example, to use the completers _complete
	      and _prefix but only allow case-insensitive completion with _complete:

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

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

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

	      If the style is unset in any context no match specification is applied.  Note  also
	      that  some completers such as _correct and _approximate do not use the match speci-
	      fications at all, though these completers will only ever be called once even if the
	      matcher-list contains more than one element.

	      Where  multiple  specifications are useful, note that the entire completion is done
	      for each element of matcher-list, which can quickly reduce the shell's performance.
	      As  a  rough  rule of thumb, 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.   How-
	      ever,  any  matcher  must  explicitly  specify case-insensitive matching if that is
	      required.

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

	      If the value for this style contains the string `numeric', the  completer  function
	      will  take  any numeric argument as the maximum number of errors allowed. For exam-
	      ple, with

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

	      two errors are allowed if no numeric argument is given, but with a numeric argument
	      of  six  (as in `ESC-6 TAB'), up to six errors are accepted.  Hence with a value of
	      `0 numeric', no correcting completion will be attempted unless a	numeric  argument
	      is given.

	      If  the value contains the string `not-numeric', the completer will not try to gen-
	      erate corrected completions when given a numeric argument, so in this case the num-
	      ber given should be greater than zero.  For example, `2 not-numeric' specifies that
	      correcting completion with two errors will usually be performed, but if  a  numeric
	      argument is given, correcting completion will not be performed.

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

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

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

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

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

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

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

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

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

	      If  the value contains the string `select', menu selection will be started uncondi-
	      tionally.

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

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

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

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

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

       muttrc If set, gives the location of the mutt configuration file.  It defaults to `~/.mut-
	      trc'.

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

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

	      For  example, suppose you type ^Xc to use the _correct_word widget, which generates
	      a list of corrections for the word under the cursor.  Usually, typing ^D would gen-
	      erate  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  gener-
	      ated.

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

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

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

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

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

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

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

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

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

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

       path-completion
	      This is used by filename completion.  By default, filename completion examines  all
	      components  of a path to see if there are completions of that component.	For exam-
	      ple, /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 com-
	      ponent in the path to be completed.   For  example,  /u/b/z  can	be  completed  to
	      /usr/bin/zsh if the cursor is after the /u.

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

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

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

	      The default value for this style is `false'.

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

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

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

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

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

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

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

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

       range  This is used by the _history completer and the _history_complete_word bindable com-
	      mand to decide which words should be completed.

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

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

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

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

	      For example,

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

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

       regular
	      This style is used by the _expand_alias completer and bindable command.  If set  to
	      `true'  (the  default),  regular aliases will be expanded but only in command posi-
	      tion.  If it is set to `false', regular aliases will never be expanded.	If it  is
	      set to `always', regular aliases will be expanded even if not in command position.

       rehash If  this is set when completing external commands, the internal list (hash) of com-
	      mands 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  connec-
	      tions  to  retrieve  remote  information.  This includes the completion for the CVS
	      command.

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

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

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

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

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

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

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

       sort   Many  completion	widgets call _description at some point which decides whether the
	      matches are added sorted or unsorted (often indirectly via _wanted or  _requested).
	      This  style  can	be  set explicitly to one of the usual true or false values as an
	      override.  If it is not set for the context, the standard behaviour of the  calling
	      widget is used.

	      The  style  is tested first against the full context including the tag, and if that
	      fails to produce a value against the context without the tag.

	      If the calling widget explicitly requests unsorted matches, this	is  usually  hon-
	      oured.   However,  the  default  (unsorted) behaviour of completion for the command
	      history may be overridden by setting the style to true.

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

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

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

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

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

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

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

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

	      The default for this style is `false'.

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

	      The default is `true'.

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

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

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

	      For example:

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

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

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

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

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

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

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

	      tag:label:description
		     As before, but description will replace the `%d' in the value of the  format
		     style  instead  of  the default description supplied by the completion func-
		     tion.  Spaces in the description must be quoted with a  backslash.   A  `%d'
		     appearing	in description 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 patterns in the  form
	      `{pat1,pat2...}'.  In this case all matching tags will be used except for any given
	      explicitly in the same string.

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

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

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

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

		     zstyle ':completion:*' tag-order \
			 'options:-long:long\ options
			  options:-short:short\ options
			  options:-single-letter:single\ letter\ options'

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

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

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

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

	      First,  all  the	tags offered when completing after foo are tried using the normal
	      tag name.  If that generates no matches, the second value  of  tag-order	is  used,
	      which  tries  all  tags  again except that this time each has -case appended to its
	      name for lookup of styles.  Hence this time the value for the  matcher  style  from
	      the  second  call to zstyle in the example is used to make completion case-insensi-
	      tive.

	      It is possible to use the -e option of the zstyle builtin command to specify condi-
	      tions 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 func-
	      tion will be used to provide a sensible  default	behavior  that	causes	arguments
	      (whether	normal	command arguments or arguments of options) to be completed before
	      option names for most commands.

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

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

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

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

	      For example,

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

	      allows  completion  of  all  the	components of the URL 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 com-
	      pleted without reference to the urls style.

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

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

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

	      Note that this is only intended to smooth the transition from compctl  to  the  new
	      completion system and may disappear in the future.

	      Note  also  that the definitions from compctl will only be used if there is no spe-
	      cific completion function for the command in question.  For example, if there is	a
	      function	_foo  to  complete  arguments  to  the command foo, compctl will never be
	      invoked for foo.	However, the compctl version will  be  tried  if  foo  only  uses
	      default completion.

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

       users  This may be set to a list of usernames to be completed.  If it is not set all user-
	      names 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 prohibi-
	      tive 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 com-
	      plete usernames from this style (only), and will restrict subsequent hostname  com-
	      pletion 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 function acts as a wrapper calling
       the so-called `completer' functions that generate matches.  If  _main_complete  is  called
       with  arguments,  these	are taken as the names of completer functions to be called in the
       order given.  If no arguments are given, the set of functions to try  is  taken	from  the
       completer  style.   For	example,  to use normal completion and correction if that doesn't
       generate any matches:

	      zstyle ':completion:*' completer _complete _correct

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

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

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

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

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

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

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

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

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

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

		     zstyle ':completion:*' completer _complete _approximate

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

	      This completer uses the tags corrections and original when generating the  possible
	      corrections  and	the original string.  The format style for the former may contain
	      the additional sequences `%e' and `%o' which will be  replaced  by  the  number  of
	      errors accepted to generate the corrections and the original string, respectively.

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

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

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

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

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

       _complete
	      This  completer  generates  all possible completions in a context-sensitive manner,
	      i.e. using the settings defined with the compdef function explained above  and  the
	      current  settings  of all special parameters.  This gives the normal completion be-
	      haviour.

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

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

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

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

	      For example, with:

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

	      correction will accept up to two errors.	If a numeric argument is  given,  correc-
	      tion  will  not be performed, but correcting completion will be, and will accept as
	      many errors as given by the numeric argument.  Without a	numeric  argument,  first
	      correction and then correcting completion will be tried, with the first one accept-
	      ing two errors and the second one accepting three errors.

	      When _correct is called as a function, the number of errors to accept may be  given
	      following  the  -a option.  The argument is in the same form a values to the accept
	      style, all in one string.

	      This completer function is intended to be used without the  _approximate	completer
	      or,  as  in the example, just before it.	Using it after the _approximate completer
	      is useless since _approximate will at least generate the corrected  strings  gener-
	      ated by the _correct completer -- and probably more.

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

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

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

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

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

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

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

       _history
	      Complete words from the shell's command  history.  This completer can be controlled
	      by  the remove-all-dups, and sort styles as for the _history_complete_word bindable
	      command, see the section `Bindable Commands' below and the section `Completion Sys-
	      tem Configuration' above.

       _ignored
	      The  ignored-patterns  style  can  be  set to a list of patterns which are compared
	      against possible completions; matching ones are removed.	With this completer those
	      matches can be reinstated, as if no ignored-patterns style were set.  The completer
	      actually generates its own list of matches; which completers are invoked is  deter-
	      mined  in  the  same way as for the _prefix completer.  The single-ignored style is
	      also available as described above.

       _list  This completer allows the insertion of matches to be delayed  until  completion  is
	      attempted  a  second time without the word on the line being changed.  On the first
	      attempt, only the list of matches will be shown.	It is affected by the styles con-
	      dition 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, insert-
	      ing a `*' at the cursor position and comparing the resulting pattern with the  pos-
	      sible  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-unam-
	      biguous  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  func-
	      tions (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 completion widgets such
	      as reverse-menu-complete, or accept-and-menu-complete.

       _oldlist
	      This completer controls how the standard completion widgets behave when there is an
	      existing	list of completions which may have been generated by a special completion
	      (i.e. a separately-bound completion command).  It allows	the  ordinary  completion
	      keys  to continue to use the list of completions thus generated, instead of produc-
	      ing 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.

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

	      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  cur-
	      rent  context is used -- except, of course, the _prefix completer itself.  Further-
	      more, if this completer appears more than once in the list of completers only those
	      completers not already tried by the last invocation of _prefix will be called.

	      For example, consider this global completer style:

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

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

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

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

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

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

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

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

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

		     _func is the name of a shell function whose name must begin with  _  but  is
		     not otherwise special to the completion system.  The function is called with
		     the trial word as an argument.  If the word is to be expanded, the  function
		     should  set the array reply to a list of expansions.  Optionally, it can set
		     REPLY to a word that will be used as a description for  the  set  of  expan-
		     sions.  The return status of the function is irrelevant.
BINDABLE COMMANDS
       In  addition  to the context-dependent completions provided, which are expected to work in
       an intuitively obvious way, there are a few widgets implementing special  behaviour  which
       can be bound separately to keys.  The following is a list of these and their default bind-
       ings.

       _bash_completions
	      This function is used by two widgets, _bash_complete-word  and  _bash_list-choices.
	      It  exists  to  provide  compatibility  with completion bindings in bash.  The last
	      character of the binding determines what is completed:  `!',  command  names;  `$',
	      environment  variables; `@', host names; `/', file names; `~' user names.  In bash,
	      the binding preceded by `\e' gives completion, and preceded by `^X' lists  options.
	      As  some	of  these bindings clash with standard zsh bindings, only `\e~' and `^X~'
	      are bound by default.  To add the rest, the following should  be	added  to  .zshrc
	      after compinit has been run:

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

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

       _correct_filename (^XC)
	      Correct the filename path at the cursor position.  Allows up to six errors  in  the
	      name.   Can  also  be  called with an argument to correct a filename path, indepen-
	      dently of zle; the correction is printed on standard output.

       _correct_word (^Xc)
	      Performs correction of the current argument using the usual contextual  completions
	      as possible choices. This stores the string `correct-word' in the function field of
	      the context name and then calls the _correct completer.

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

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

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

       _generic
	      This function is not defined as a widget and not bound by default.  However, it can
	      be  used to define a widget and will then store the name of the widget in the func-
	      tion field of the context and call the completion system.  This allows custom  com-
	      pletion  widgets	with  their  own set of style settings to be defined easily.  For
	      example, to define a widget that performs normal completion and starts menu  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 context in order to
	      change the set of functions used to generate  possible  matches.	 If  _generic  is
	      called  with  arguments,	those are passed through to _main_complete as the list of
	      completers in place of those defined by the completer style.

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

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

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

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

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

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

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

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

       _complete_help (^Xh)
	      This widget displays information about the context names, the tags, and the comple-
	      tion 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  infor-
	      mation  available from the completion functions called, which in turn is determined
	      by the user's own styles and other settings.

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

	      If this widget is created using the name of the function, as it is by default, then
	      when  executed it will read a key sequence.  This is expected to be bound to a call
	      to a completion function that uses the _generic widget.  That widget will  be  exe-
	      cuted,  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  _com-
	      plete_debug_generic _complete_help_generic', it will read and execute the keystring
	      for a generic widget as before, but then generate debugging information as done  by
	      _complete_debug for contextual completion.

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

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

	      For example, after executing the following:

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

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

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

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

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

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

	      For example:

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

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

       _alternative [ -O name ] [ -C name ] spec ...
	      This function is useful in simple cases where multiple tags are available.   Essen-
	      tially 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 descrip-
	      tion descr.  The actions are those accepted by the _arguments  function  (described
	      below), excluding the `->state' and `=...' forms.

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

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

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

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

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

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

       _arguments [ -nswWACRS ] [ -O name ] [ -M matchspec ] [ : ] spec ...
	      This  function  can  be  used to give a complete specification for completion for a
	      command whose arguments follow standard UNIX option and argument conventions.   The
	      following  forms specify individual sets of options and arguments; to avoid ambigu-
	      ity, these may be separated from the options  to	_arguments  itself  by	a  single
	      colon.   Options	to  _arguments	itself must be in separate words, i.e. -s -w, not
	      -sw.

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

	      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  argu-
		     ment is optional.	If the message contains only white space, nothing will be
		     printed above the matches unless  the  action  adds  an  explanation  string
		     itself.

	      :message:action
	      ::message:action
		     Similar,  but  describes  the next argument, whatever number that happens to
		     be.  If all arguments are 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 begin-
		     ning 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 evaluated.  With three colons before the message
		     they are modified to refer only to the  normal  arguments	covered  by  this
		     description.

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

		     By  default, options are multi-character name, one `-word' per option.  With
		     -s, options may be single characters, with more than one  option  per  word,
		     although words starting with two hyphens, such as `--prefix', are still con-
		     sidered complete option names.  This is suitable for standard GNU options.

		     The combination of -s with -w allows single-letter options to be combined in
		     a	single word even if one or more of the options take arguments.	For exam-
		     ple, if -a takes an argument, with no -s `-ab' is	considered  as	a  single
		     (unhandled)  option;  with  -s  -ab is an option with the argument `b'; with
		     both -s and -w, -ab may be the option -a and the option  -b  with	arguments
		     still to come.

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

		     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 cur-
			    sor it will not be offered again.

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

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

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

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

		     -optname+
			    The first argument may appear immediately after optname in	the  same
			    word,  or  may appear as a separate word after the option.	For exam-
			    ple, `-foo+:...' specifies 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 brackets, as in `-q[query operation]'.

			    The  verbose  style is used to decide whether the explanation strings
			    are displayed with the option in a completion listing.

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

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

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

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

		     This  group  may  be repeated for options which take multiple arguments.  In
		     other words, :message1:action1:message2:action2 specifies	that  the  option
		     takes two arguments.

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

		     Multiple colons are treated as for the `*:...' forms for ordinary arguments:
		     when the message is preceded by two colons, the words special array 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 argu-
       ment numbers.  If the given option is on the command line, the options and arguments indi-
       cated 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
       normal  (non-option-)  arguments; and a hyphen (-) for all options.  For example, if `(*)'
       appears before an option and the option appears on the command line, the list of remaining
       arguments (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
       arguments are given by an array, and _arguments is called  repeatedly  for  more  specific
       contexts:  on the first call `_arguments $global_options' is used, and on subsequent calls
       `_arguments !$^global_options'.

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

       The 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 message will be displayed but no completions  listed.
	      Note  that  even in this case the colon at the end of the message is needed; it may
	      only be omitted when neither a message nor an action is given.

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

		     :foo:(foo bar baz)

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

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

	      The  matches  will  be  listed  together with their 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  con-
	      trol  to the calling function with parameters set to indicate the state of process-
	      ing; the calling function then makes its own arrangements  for  generating  comple-
	      tions.   For example, functions that implement a state machine 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 contain-
	      ing such an action.

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

	      In  addition to $state and $state_descr, _arguments also sets the global parameters
	      `context', `line' and `opt_args' as described below, and does not reset any changes
	      made  to	the  special parameters such 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 containing a `->string' must
	      therefore declare appropriate local parameters:

		     local context state state_descr line
		     typeset -A opt_args

	      to prevent _arguments from altering the global environment.

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

       = action
	      If  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  comple-
	      tion 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 com-
	      mand line on which the action is to operate (the two- and three-colon forms above).
	      One  particular  use  is	when  an  action itself causes _arguments on a restricted
	      range; it is 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 invoked unchanged.

	      Otherwise it will be invoked with some extra strings placed after the  first  word;
	      these  are  to  be passed down as options to the compadd builtin.  They ensure that
	      the state specified by _arguments, in particular the descriptions  of  options  and
	      arguments,  is  correctly passed to the completion command.  These additional argu-
	      ments are taken from the array parameter `expl'; this will be set up before execut-
	      ing 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 command name  and
       normal arguments from the command line, i.e. the words from the command line excluding all
       options and their arguments.  Options are stored in the associative array `opt_args'  with
       option  names  as keys and their arguments as the values.  For options that have more than
       one argument these are given as one string, separated by colons.  All colons in the origi-
       nal arguments are preceded with backslashes.

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

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

       It  is  possible to specify multiple sets of options and arguments with the sets separated
       by single hyphens.  The specifications before the first hyphen (if any) are shared by  all
       the  remaining  sets.  The first word in every other set provides a name for the set which
       may appear in exclusion lists in specifications, either alone or before one of the  possi-
       ble  values described above.  In the second case a `-' should appear between this name and
       the remainder.

       For example:

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

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

       If the name given for one of the mutually exclusive sets is of the form `(name)' then only
       one value from each set will ever be completed;	more  formally,  all  specifications  are
       mutually exclusive to all other specifications in the same set.	This is useful for defin-
       ing multiple sets of options which are mutually exclusive and in  which	the  options  are
       aliases for each other.	For example:

	      _arguments \
		  -a -b \
		- '(compress)' \
		  {-c,--compress}'[compress]' \
		- '(uncompress)' \
		  {-d,--decompress}'[decompress]'

       As  the completion code has to parse the command line separately for each set this form of
       argument is slow and should only be used when necessary.  A useful alternative is often an
       option  specification with rest-arguments (as in `-foo:*:...'); here the option -foo swal-
       lows up all remaining arguments as described by the optarg definitions.

       The options -S and -A are available to simplify the specifications for commands with stan-
       dard  option  parsing.  With -S, no option will be completed after a `--' appearing on its
       own on the line; this argument will otherwise be ignored; hence in the line

	      foobar -a -- -b

       the `-a' is considered an option but the `-b' is considered an argument, while the `--' is
       considered to be neither.

       With  -A,  no  options  will be completed after the first non-option argument on the line.
       The -A must be followed by a pattern matching all strings which are not	to  be	taken  as
       arguments.  For example, to make _arguments stop completing options after the first normal
       argument, but ignoring all strings starting with a hyphen even if they are  not	described
       by one of the optspecs, the form is `-A "-*"'.

       The option `-O name' specifies the name of an array whose elements will be passed as argu-
       ments to functions called to execute actions.  For example, this can be used to	pass  the
       same set of options for the compadd builtin to all actions.

       The option `-M spec' sets a match specification to use to completion option names and val-
       ues.  It must appear before the first argument specification.  The default  is  `r:|[_-]=*
       r:|=*':	this  allows partial word completion after `_' and `-', for example `-f-b' can be
       completed to `-foo-bar'.

       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.

       The option `--' allows _arguments to work out the names of long options that  support  the
       `--help'  option  which is standard in many GNU commands.  The command word is called with
       the argument `--help' and the output examined for option names.	Clearly, it can  be  dan-
       gerous  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  avail-
       able 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 specifiers of the form  `pattern:mes-
       sage:action'; note that normal _arguments specifiers are not used.  The pattern is matched
       against the help text for an option, and if it matches the message and action are used  as
       for other argument specifiers.  For example:

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

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

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

       so that the above specifications will cause directories to be  completed  after	`--direc-
       tory', though not after `-C'.

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

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

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

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

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

       The  `_arguments  --' form can also be followed by the option `-s pair' to describe option
       aliases.  Each pair consists of a pattern and a replacement.  For  example,  some  config-
       ure-scripts  describe options only as `--enable-foo', but also accept `--disable-foo'.  To
       allow completion of the second form:

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

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

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

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

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

       The `-copy' option may appear more than once on the command line and takes two  arguments.
       The  first  is  mandatory  and  will  be  completed as a filename.  The second is optional
       (because of the second colon before the description `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  com-
       pleted.	The last description gives all other arguments the description `page numbers' but
       does not offer completions.

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

	      Example:

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

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

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

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

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

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

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

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

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

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

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

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

	      The descr is taken as a string to display above the matches if the format style for
	      the descriptions tag is set.  This is followed by one or two names of  arrays  fol-
	      lowed by options to pass to compadd.  The first array contains the possible comple-
	      tions with their descriptions in the form  `completion:description'.   Any  literal
	      colons  in completion must be quoted with a backslash.  If a second array is given,
	      it should have the same number of elements as the first; in this	case  the  corre-
	      sponding	elements  are  added  as  possible  completions instead of the completion
	      strings from the first array.  The completion list  will	retain	the  descriptions
	      from the first array.  Finally, a set of completion options can appear.

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

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

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

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

       _description [ -x ] [ -12VJ ] tag name descr [ spec ... ]
	      This  function  is not to be confused with the previous one; it is used as a helper
	      function for creating options to 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 tradition-
	      ally  `expl', but this convention is not enforced).  The description for the corre-
	      sponding set of matches is passed to the function in descr.

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

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

	      If _description is called with more than	three  arguments,  the	additional  specs
	      should  be  of  the form `char:str'.  These supply escape sequence replacements for
	      the format style: every appearance of `%char' will be replaced by string.

	      If the -x option is given, the description will be passed to compadd using  the  -x
	      option  instead  of  the	default -X.  This means that the description will be dis-
	      played 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.

       _dispatch context string ...
	      This sets the current context to context and looks for completion functions to han-
	      dle  this  context by hunting through the list of command names or special contexts
	      (as described above for compdef) given as string ....  The first	completion  func-
	      tion to be defined for one of the contexts in the list is used to generate matches.
	      Typically, the last string is -default- to cause the function for  default  comple-
	      tion 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.

       _files The  function  _files calls _path_files with all the arguments it was passed except
	      for -g and -/.  The use of  these  two  options  depends	on  the  setting  of  the
	      file-patterns style.

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

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

		     compdef _gnu_generic foo bar

	      after the call to compinit.

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

       _guard [ options ] pattern descr
	      This function is intended to be used in the action for the specifications passed to
	      _arguments and similar functions.  It returns immediately with  a  non-zero  return
	      status  if  the  string to be completed does not match the pattern.  If the pattern
	      matches, the descr is displayed; the function then returns status zero if the  word
	      to complete is not empty, non-zero otherwise.

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

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

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

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

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

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

	      If the -r option is given, no style is used; the descr is taken  literally  as  the
	      string  to  display.  This is most useful when the descr comes from a pre-processed
	      argument list which already contains an expanded description.

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

	      The  second  form  gives a description for completions with the tag tag to be shown
	      even if there are no matches for that tag.  The tag can be omitted and  if  so  the
	      tag  is taken from the parameter $curtag; this is maintained by the completion sys-
	      tem and so is usually correct.

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

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

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

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

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

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

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

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

       _normal
	      This is the standard function called to handle completion outside any special -con-
	      text-.  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  com-
	      mand, and if there is none it uses the completion for the -default- context.

	      A second use is to reexamine the command line specified by the $words array and the
	      $CURRENT parameter after those have been modified.  For example, the function _pre-
	      command,	which  completes  after pre-command specifiers such as nohup, removes the
	      first word from the words array, decrements the CURRENT parameter, then calls _nor-
	      mal  again.   The effect is that `nohup cmd ...' is treated in the same way as `cmd
	      ...'.

	      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 parame-
	      ter _compskip is checked.  If it is set completion is terminated at that point even
	      if no matches have been found.  This is the same effect as in the -first- context.

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

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

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

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

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

	      All other arguments are passed to the compadd builtin.

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

	      The options accepted by both _path_files and _files are:

	      -f     Complete all filenames.  This is the default.

	      -/     Specifies that only directories should be completed.

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

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

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

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

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

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

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

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

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

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

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

	      The arguments are grouped as sets of alternatives separated by `|', which are tried
	      one  after the other until one matches.  Each alternative consists of a one or more
	      specifications which are tried left to  right,  with  each  pattern  matched  being
	      stripped	in  turn  from the command line being tested, until all of the group suc-
	      ceeds 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 pro-
	      ceeds from inside to outside.

	      A special procedure is applied if no test succeeds but the remaining  command  line
	      string contains no null character (implying the remaining word is the one for which
	      completions are to be generated).  The  completion  target  is  restricted  to  the
	      remaining  word  and  any  actions for the corresponding patterns are executed.  In
	      this case, nothing is stripped from the command line string.  The order of  evalua-
	      tion  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  com-
		     bined 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 specifica-
		     tions are examined to find something to complete.	If a component is reached
		     but  no  such  pattern exists yet on the command line, the string containing
		     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 previous patterns) is also consid-
		     ered part of the completion target.

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

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

	      spec # This allows any number of repetitions of spec.

	      spec spec
		     The two specs are to be matched one after the other as described above.

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

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

	      Examples:

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

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

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

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

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

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

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

	      This is similar, but either aaa or bbb may be completed for any argument.  In  this
	      case  _regex_words  could  be  used to generate a suitable expression for the argu-
	      ments.

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

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

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

	      The second part of spec is a description for the word being completed.

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

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

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

	      For example:

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

	      This  shows  a completion function for a command mydb which takes two command argu-
	      ments, 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 args ... ] ]
	      This function is called to decide whether a tag already registered  by  a  call  to
	      _tags  (see  below)  has	been requested by the user and hence completion should be
	      performed for it.  It returns status zero if the tag is requested and non-zero oth-
	      erwise.	The  function  is typically used as part of a loop over different tags as
	      follows:

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

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

	      If name and descr are given, _requested calls the _description function with  these
	      arguments together with the options passed to _requested.

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

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

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

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

	      See _store_cache below for more details.

       _sep_parts
	      This function is passed alternating arrays and separators as arguments.  The arrays
	      specify  completions  for  parts of strings to be separated by the separators.  The
	      arrays may be the names of array parameters or a quoted list of words in	parenthe-
	      ses.   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.

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

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

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

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

	      The  cache_identifier  specifies	the file which the data should be dumped to.  The
	      file is stored in a directory specified by the cache-path style which  defaults  to
	      ~/.zcompcache.   The  remaining  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 with-
	      out 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 ] tags ... ]
	      If called with arguments, these are taken to be the names of tags valid for comple-
	      tions 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  func-
	      tion.   This  successively selects the first, second, etc. set of tags requested by
	      the user.  The return status is zero if at least one of the tags is  requested  and
	      non-zero	otherwise.   To  test  if a particular tag is to be tried, the _requested
	      function should be called (see above).

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

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

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

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

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

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

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

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

	      Example:

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

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

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

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

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

		     local context state state_descr line
		     typeset -A val_args

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

	      Note also that _values normally adds the character used as  the  separator  between
	      values  as an auto-removable suffix (similar to a `/' after a directory).  However,
	      this is not possible for a `->string' action as the matches for  the  argument  are
	      generated  by  the calling function.  To get the usual behaviour, the calling func-
	      tion 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 args ...
	      In many contexts, completion can only generate one particular set of matches,  usu-
	      ally  corresponding  to  a  single  tag.	 However, it is still necessary to decide
	      whether the user requires matches of this type.  This function is useful in such	a
	      case.

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

	      Hence to offer only one tag and immediately add the corresponding matches with  the
	      given description:

		     local expl
		     _wanted tag expl 'description' \
			 compadd matches...

	      Note  that,  as  for  _requested,  the command must be able to accept options to be
	      passed down to compadd.

	      Like _tags this function supports the -C option to give a different  name  for  the
	      argument context field.  The -x option has the same meaning as for _description.

COMPLETION DIRECTORIES
       In  the source distribution, the files are contained in various subdirectories of the Com-
       pletion directory.  They may have been installed in the same structure, or into one single
       function  directory.   The  following  is a description of the files found in the original
       directory structure.  If you wish to alter an installed file, you will need to copy it  to
       some  directory	which  appears earlier in your fpath than the standard directory where it
       appears.

       Base   The core functions and special completion widgets automatically bound to keys.  You
	      will  certainly  need  most  of these, though will probably not need to alter them.
	      Many of these are documented above.

       Zsh    Functions for completing arguments of shell builtin commands and utility	functions
	      for this.  Some of these are also used by functions from 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 direc-
	      tories, as well as the X directory, may be useful on your system.

zsh 5.0.2				December 21, 2012			    ZSHCOMPSYS(1)
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