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

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

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

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

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

       Styles  modify various operations of the completion system, such as output formatting, but
       also what kinds of completers are used (and in what order), or which  tags  are  examined.
       Styles  may accept arguments and are manipulated using the zstyle command described in 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
       function  should  be called to produce the completions, and calls it. The result is passed
       to one or more completers, functions  that  implement  individual  completion  strategies:
       simple  completion,  error  correction,  completion with error correction, menu selection,
       etc.

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

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

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
       compinstall, although lines using the command `zstyle' should be gracefully handled.

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

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

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

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

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

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

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

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

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

       For  security  reasons  compinit  also checks if the completion system would use files not
       owned by root or by the  current  user,  or  files  in  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
       completion  system  directories,  adding  missing  ones to fpath as necessary.  To force a
       check of exactly the directories currently named in fpath, set _compdir to an empty string
       before calling compaudit or compinit.

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

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

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

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

       The tags are:

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

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

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

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

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

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

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

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

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

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

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

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

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

       -command-
              A word in command position

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

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

       -equal-
              A word beginning with an equals sign

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

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

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

       -redirect-
              The word after a redirection operator.

       -subscript-
              The contents of a parameter subscript.

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

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

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

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

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

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

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

       As an example:

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

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

       Also:


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

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

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

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

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

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

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

              The function argument may alternatively be a string  containing  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
              patterns tried initially, patterns tried finally, and normal commands and contexts.

              The  parameter $_compskip may be set by any function defined for a pattern context.
              If it  is  set  to  a  value  containing  the  substring  `patterns'  none  of  the
              pattern-functions  will be called; if it is set to a value containing the substring
              `all', no other function will be called.

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

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

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

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

              compdef _pids foo

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

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

COMPLETION SYSTEM CONFIGURATION

       This section gives a short overview of how the completion  system  works,  and  then  more
       detail on how users can configure how and when matches are generated.

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

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

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

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

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

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

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

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

       ·      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.

       ·      The  argument;  this  indicates  which  command  line  or  option  argument  we are
              completing.  For command arguments this generally takes the form argument-n,  where
              n is the number of the argument, and for 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.

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

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

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

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

              dvips -o ...

       and the completion function will generate filenames.

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

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

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

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

              zstyle ':completion:*' verbose yes

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

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

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

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

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

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

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

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

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

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

       A  good rule of thumb is that any completion style pattern that needs to include more than
       one wildcard (*) and that does not end in a tag name, should include all six  colons  (:),
       possibly surrounding additional wildcards.

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

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

       accounts
              used to look up the users-hosts style

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

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

       arguments
              for arguments to a command

       arrays for names of array parameters

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

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

       builtins
              for names of builtin commands

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

       colormapids
              for X colormap ids

       colors for color names

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

       contexts
              for contexts in arguments to the zstyle builtin command

       corrections
              used by the _approximate and _correct completers for possible corrections

       cursors
              for cursor names used by X programs

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

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

       devices
              for names of device special files

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

       directory-stack
              for entries in the directory stack

       displays
              for X display names

       domains
              for network domains

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

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

       extensions
              for X server extensions

       file-descriptors
              for numbers of open file descriptors

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

       fonts  for X font names

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

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

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

       groups for names of user groups

       history-words
              for words from the history

       hosts  for hostnames

       indexes
              for array indexes

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

       interfaces
              for network interfaces

       keymaps
              for names of zsh keymaps

       keysyms
              for names of X keysyms

       libraries
              for names of system libraries

       limits for system limits

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

       manuals
              for names of manual pages

       mailboxes
              for e-mail folders

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

       messages
              used to look up the format style for messages

       modifiers
              for names of X modifiers

       modules
              for modules (e.g. zsh modules)

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

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

       names  for all kinds of names

       newsgroups
              for USENET groups

       nicknames
              for nicknames of NIS maps

       options
              for command options

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

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

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

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

       parameters
              for names of parameters

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

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

       pods   for perl pods (documentation files)

       ports  for communication ports

       prefixes
              for prefixes (like those of a URL)

       printers
              for print queue names

       processes
              for process identifiers

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

       sequences
              for sequences (e.g. mh sequences)

       sessions
              for sessions in the zftp function suite

       signals
              for signal names

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

       styles for styles used by the zstyle builtin command

       suffixes
              for filename extensions

       tags   for tags (e.g. rpm tags)

       targets
              for makefile targets

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

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

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

       users  for usernames

       values for one of a set of values in certain lists

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

       visuals
              for X visuals

       warnings
              used to look up the format style for warnings

       widgets
              for zsh widget names

       windows
              for IDs of X windows

       zsh-options
              for shell options

   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
              completions to /usr.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       file-list
              This  style  controls  whether files completed using the standard builtin mechanism
              are to be listed with a long list similar to ls -l.  Note that  this  feature  uses
              the  shell  module zsh/stat for file information; this loads the builtin stat 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
              distinguishable from the colon before the tag.  If more than one pattern is needed,
              the patterns can be given inside braces, separated by commas.

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

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

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

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

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

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

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

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

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

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

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

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

       format If this is set for the descriptions tag, its value is used as a string  to  display
              above  matches  in  completion  lists.   The  sequence  `%d' in this string will be
              replaced with a short description of what these matches are.  This string may  also
              contain  the  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  sequence  `%G'
              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),
              globbing will be attempted on the words resulting from a previous substitution (see
              the substitute style) or else the original string from the line.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              parent The name of any directory whose path is already contained in the word on the
                     line  is ignored.  For example, when completing 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
                     directory.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       list-colors
              If the zsh/complist module  is  loaded,  this  style  can  be  used  to  set  color
              specifications.   This mechanism replaces the use of the ZLS_COLORS and ZLS_COLOURS
              parameters described in the 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
              certain completion listings more compact by grouping matches.  For example, options
              for commands that have the same description (shown when the verbose style is set to
              `true')  will  appear  as  a  single entry.  However, menu selection can be used to
              cycle through all the matches.

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

       list-prompt
              If  this  style  is set for the default tag, completion lists that don't fit on the
              screen can  be  scrolled  (see  the  description  of  the  zsh/complist  module  in
              zshmodules(1)).   The value, if not the empty string, will be displayed after every
              screenful and the shell will prompt for a key press; if the style  is  set  to  the
              empty string, a default prompt will be used.

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

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

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

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

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

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

              For example:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              The default value for this style is `false'.

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

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

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

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

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

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

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

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

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

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

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

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

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

              For example,

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

              If  the  current directory is /home/pws/zsh/Src, then zle_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
              position.  If it is set to `false', regular aliases will never be expanded.   If it
              is  set  to  `always',  regular  aliases  will  be  expanded even if not in command
              position.

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

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

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

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

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

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

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

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

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

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

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

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

              If  the  calling  widget  explicitly  requests  unsorted  matches,  this is usually
              honoured.  However, the default (unsorted) behaviour of completion for the  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
              context will be used.

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

              For example:

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

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

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

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

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

              tag:label ...
                     Here, tag is one of the standard  tags  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
                     function.   Spaces  in  the  description must be quoted with a backslash.  A
                     `%d' appearing in description is replaced with the description given by  the
                     completion function.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              For example,

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

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

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

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

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

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

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

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

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

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

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

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

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

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

CONTROL FUNCTIONS

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

              zstyle ':completion:*' completer _complete _correct

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

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

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

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

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

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

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

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

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

       _approximate
              This  is  similar  to  the  basic _complete completer but allows the completions to
              undergo corrections.  The  maximum  number  of  errors  can  be  specified  by  the
              max-errors style; see the description of approximate matching in 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
              completions with two errors will be shown, and so on.  It  modifies  the  completer
              name  in the context to indicate the number of errors being tried: on the first try
              the completer field contains `approximate-1', on the  second  try  `approximate-2',
              and so on.

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

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

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

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

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

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

              See _description for a description of tag and descr.

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

              This function takes no arguments.

       _cmdstring
              Completes an external command as a single argument, as for system(...).

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

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

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

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

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

              For example, with:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

       _menu  This completer was written as simple example function to show how  menu  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
              producing  a  new list of ordinary contextual completions.  It should appear in the
              list of completers before any of the widgets which generate matches.  It  uses  two
              styles:  old-list  and  old-menu, see the section `Completion System Configuration'
              above.

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

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

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

              For example, consider this global completer style:

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

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

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

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

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

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

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

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

              $hash

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

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

BINDABLE COMMANDS

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              For example, after executing the following:

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

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

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

UTILITY FUNCTIONS

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

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

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

              For example:

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

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

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

              The tags to use and the action to perform if a tag is requested are described using
              the  specs  which  are of the form: `tag:descr:action'.  The tags are offered using
              _tags and if  the  tag  is  requested,  the  action  is  executed  with  the  given
              description  descr.   The  actions  are  those  accepted by the _arguments function
              (described below), excluding the `->state' and `=...' forms.

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

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

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

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

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

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

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

              Options Overview

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

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

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

              The options of _arguments have the following meanings:

              -n     With  this  option, _arguments sets the 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 parameter is not used.

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

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

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

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

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

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

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

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

                            foobar -x -- -y

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

              -A pat Do not complete options after the first non-option  argument  on  the  line.
                     pat  is  a  pattern  matching  all  strings  which  are  not  to be taken as
                     arguments.  For example, to make _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
                     "-*"'.

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

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

              specs: overview

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

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

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

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

                     With  two colons before the message, 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.

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

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

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

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

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

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

                     -optname+
                            The first argument may appear immediately after optname in  the  same
                            word,  or  may  appear  as  a  separate  word  after the option.  For
                            example, `-foo+:...' specifies that the 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 taking multiple arguments may be given in this form.   If  the
                            pattern  is empty (i.e. :*:), all the remaining words on the line are
                            to be completed as described by the action; otherwise, all the  words
                            up  to  and including a word matching the pattern are to be completed
                            using the action.

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

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

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

              Other items may appear in the list of excluded options to  indicate  various  other
              items  that  should  not  be  applied  when the current specification is matched: a
              single star (*) for the rest arguments (i.e. a specification of the form  `*:...');
              a  colon  (:)  for  all  normal  (non-option-)  arguments; and a hyphen (-) for all
              options.  For example, if `(*)' appears before an option and the option appears  on
              the  command  line, the list of remaining arguments (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'.

              specs: actions

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

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

              The forms for action are as follows.

               (single unquoted space)
                     This is useful where an argument is required  but  it  is  not  possible  or
                     desirable  to generate matches for it.  The 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  control to the calling function with parameters set to indicate the
                     state of processing; the calling function then makes  its  own  arrangements
                     for  generating  completions.  For example, functions that implement a state
                     machine can use this type of action.

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

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

                     In  addition  to  $state  and  $state_descr, _arguments also sets the global
                     parameters `context', `line' and `opt_args' as described below, and does not
                     reset  any  changes made to the special parameters such 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 completion command line while  not  changing
                     the point at which completion is taking place.

                     This  is  most  useful with one of the specifiers that restrict the words on
                     the command line on which the action is to operate (the two- and three-colon
                     forms above).  One particular use is when 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  arguments  are  taken from the array parameter
                     `expl'; this will be set up before executing the action  and  hence  may  be
                     referred  to  inside  it,  typically  in an expansion of the form `$expl[@]'
                     which preserves empty elements of the array.

              During the performance of the action the array `line' will be  set  to  the  normal
              arguments  from  the  command  line, i.e. the words from the command line after the
              command name excluding all options and their arguments.  Options are stored in  the
              associative  array  `opt_args' with option names as keys and their arguments as the
              values.  For options that have more than  one  argument  these  are  given  as  one
              string,  separated by colons.  All colons and backslashes in the original arguments
              are preceded with backslashes.

              The parameter `context' is set when returning to the calling function to perform an
              action  of the form `->string'.  It is set to an array of elements corresponding to
              the elements of $state.  Each 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
              parameter  is  altered  to  append  the  same  string that is stored in the context
              parameter.

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

                     local curcontext="$curcontext"

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

              Grouping Options

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

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

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

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

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

              Specifying Multiple Sets of Arguments

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

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

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

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

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

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

              Deriving spec forms from the help output

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

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

              For example:

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

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

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

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

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

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

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

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

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

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

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

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

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

              Miscellaneous notes

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

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

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

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

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

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

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

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

              Example:

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

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

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

       _call_program [ -l ] [ -p ] tag string ...
              This  function provides a mechanism for the user to override the use of an external
              command.  It looks up the command style with the supplied tag.   If  the  style  is
              set,  its  value  is  used as the command to execute.  The 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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              The descr is taken as a string to display above the matches if the format style for
              the descriptions tag is set.  This is followed  by  one  or  two  names  of  arrays
              followed  by  options  to  pass  to compadd.  The array name1 contains the possible
              completions with their descriptions  in  the  form  `completion:description'.   Any
              literal colons in completion must be quoted with a backslash.  If a name2 is given,
              it should have the same number of elements as name1; in this case the corresponding
              elements  are  added as possible completions instead of the completion strings from
              name1.  The completion list will retain the descriptions from  name1.   Finally,  a
              set of completion options can appear.

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

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

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

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

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

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

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

              The styles tested are: format, hidden, matcher,  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
              displayed even if there are no corresponding matches.

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

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

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

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

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

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

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

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

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

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

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

              -n plugin
                     Complete aliases from plugin.

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

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

              Writing plugins

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

       _files The function _files 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 displays descr if pattern matches the string to be completed.  It  is
              intended  to  be used in the action for the specifications passed to _arguments and
              similar functions.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              All other arguments are passed to the compadd builtin.

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

              The options accepted by both _path_files and _files are:

              -f     Complete all filenames.  This is the default.

              -/     Specifies that only directories should be completed.

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

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

              -F ignored-files
                     This  behaves  as  for  the corresponding option to 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 [ arg ... ]
              This function is used to resolve situations where a single  command  name  requires
              more  than  one  type  of  handling, either because it has more than one variant or
              because there is a name clash between two different commands.

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

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

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

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

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

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

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

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

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

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

                     A component is used as follows: pattern is tested to see  if  the  component
                     already   exists   on   the   command  line.   If  it  does,  any  following
                     specifications are examined to find 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
                     considered part of the completion target.

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

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

              spec # This allows any number of repetitions of spec.

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

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

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

              Examples:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              For example:

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

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

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

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

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

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

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

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

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

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

              See _store_cache below for more details.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

              Example:

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

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

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

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

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

                     local context state state_descr line
                     typeset -A val_args

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

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

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

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

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

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

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

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

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

       _widgets [ -g pattern ]
              This  function  completes  names  of  zle  widgets  (see  the  section `Widgets' in
              zshzle(1)).  The pattern, if present, is matched against  values  of  the  $widgets
              special  parameter,  documented  in  the  section  `The zsh/zleparameter Module' in
              zshmodules(1).

COMPLETION SYSTEM VARIABLES

       There are some standard variables, initialised by the  _main_complete  function  and  then
       used from other functions.

       The standard variables are:

       _comp_caller_options
              The completion system uses setopt to set a number of options. This allows functions
              to be written without concern for compatibility with every possible combination  of
              user  options.  However,  sometimes completion needs to know what the user's option
              preferences are. These are saved in  the  _comp_caller_options  associative  array.
              Option  names, spelled in lowercase without underscores, are mapped to one or other
              of the strings `on' and `off'.

              _comp_priv_prefix
                     Completion functions such as _sudo can set the _comp_priv_prefix array to  a
                     command  prefix  that  may  then  be  used  by  _call_program  to  match the
                     privileges when calling programs to generate matches.

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

COMPLETION DIRECTORIES

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

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

       Zsh    Functions for completing arguments of shell builtin commands and utility  functions
              for this.  Some of these are also used by functions from the Unix directory.

       Unix   Functions  for  completing  arguments  of external commands and suites of commands.
              They may need modifying for your system, although in many  cases  some  attempt  is
              made  to decide which version of a command is present.  For example, completion for
              the mount command tries to determine the system it is running on, while  completion
              for many other utilities try to decide whether the GNU version of the command is in
              use, and hence whether the --help option is supported.

       X, AIX, BSD, ...
              Completion and utility function for commands available only on some systems.  These
              are  not  arranged  hierarchically,  so,  for  example,  both  the Linux and Debian
              directories, as well as the X directory, may be useful on your system.