# man > ZSHCOMPSYS(1)

[_ZSHCOMPSYS_(1)](https://www.chedong.com/phpMan.php/man/ZSHCOMPSYS/1/markdown)                          General Commands Manual                         [_ZSHCOMPSYS_(1)](https://www.chedong.com/phpMan.php/man/ZSHCOMPSYS/1/markdown)

## 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)](https://www.chedong.com/phpMan.php/man/zshcompwid/1/markdown).

       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  in‐
       dicating a class of object that the user may need to distinguish.  For example, when complet‐
       ing  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 _zshmod‐_
       [_ules_(1)](https://www.chedong.com/phpMan.php/man/ules/1/markdown).

       In summary, tags describe _what_ the completion objects are, and style **how **they are to be  com‐
       pleted.  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 descrip‐
       tion  of context handling, which determines how tags and other elements of the context influ‐
       ence 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  comple‐
       tion, 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 **compin‐**
       **stall **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 de‐
       finitions, 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  au‐
       toloaded (`**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 nec‐
       essary shell functions to be autoloaded, and will then re-define all widgets that do  comple‐
       tion to use the new system.  If you use the **menu-select **widget, which is part of the **zsh/com‐**
       **plist  **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 expan‐
       sion.

       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  **#com‐**
       **pdef  **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, provided the dumpfile exists.

       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 di‐
       rectories, adding missing ones to **fpath **as necessary.  To force a check of exactly the direc‐
       tories 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  under‐
       score;  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  **automati‐
       cally contains the required directories for the standard functions.

       For incomplete installations, if **compinit **does not find enough files beginning with an under‐
       score  (fewer  than twenty) in the search path, it will try to find more by adding the direc‐
       tory **_compdir **to the search path.  If that directory has a subdirectory named **Base**, all  sub‐
       directories will be added to the path.  Furthermore, if the subdirectory **Base **has a subdirec‐
       tory 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 _name_s, each of which is either the name of a command whose arguments are to
              be completed or one of a number of special contexts in the  form  **-_**context_**-  **described
              below.

              Each _name_ may also be of the form `_cmd_**=_**service_'.  When completing the 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-sequence_s,  if any.  The _style_ must be one of the builtin widgets that
              perform completion, namely **complete-word**, **delete-char-or-list**, **expand-or-complete**, **ex‐**
              **pand-or-complete-prefix**, **list-choices**, **menu-complete**, **menu-expand-or-complete**, or  **re‐**
              **verse-menu-complete**.   If  the  **zsh/complist  **module is loaded (see [_zshmodules_(1)](https://www.chedong.com/phpMan.php/man/zshmodules/1/markdown)) the
              widget **menu-select **is also available.

              When one of the _key-sequence_s is typed, the function in the file will  be  invoked  to
              generate  the  matches.   Note that a key will not be re-bound if it already was (that
              is, was bound to something other 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  _wid‐_
              _get-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_**=(_**..._**)**')

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

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

### -command-
              A word in command position

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

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

### -equal-
              A word beginning with an equals sign

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

### -math- 

### -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
### -_ - 
       `**-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  exam‐
       ple,  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  han‐
       dler 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 comple‐
              tion function.  For example, to complete files ending in `**.h**' as arguments to the com‐
              mand **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 _name_s may also contain **-p**, **-P **and **-N **options as described for  the  **#compdef  **tag.
              The  effect  on  the argument list is identical, switching between definitions of pat‐
              terns tried initially, patterns tried finally, and normal commands and contexts.

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

              The  form  with  **-k  **defines  a widget with the same name as the _function_ that will be
              called for each of the _key-sequence_s; this is like the **#compdef -k **tag.  The  function
              should generate the completions needed and will otherwise behave like the builtin wid‐
              get  whose name is given as the _style_ argument.  The widgets usable for this are: **com‐**
              **plete-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-seq_uence,  where
              the latter two are as for **-k **and the first must be a unique widget name beginning with
              an underscore.

              Wherever  applicable, the **-a **option makes the _function_ autoloadable, equivalent to **au‐**
              **toload -U _**function_.

       The function **compdef **can be used to associate existing completion  functions  with  new  com‐
       mands.  For example,

              **compdef _pids foo**

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

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

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

### Overview
       When  completion  is  attempted  somewhere  on  the command line the completion system begins
       building the context.  The context represents everything that the shell knows about the mean‐
       ing 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 op‐
       tion as an argument).

       The context starts out very generic ("we are beginning a completion") and becomes  more  spe‐
       cific  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 ex‐
       ample  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)](https://www.chedong.com/phpMan.php/man/zshmodules/1/markdown)).

       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  sur‐
       rounding  colons appear anyway.  The fields are always in the order **:completion:_**function_**:_**com‐_
       _pleter_**:_**command_**:_**argument_**:_**tag_.  These have the following meaning:

       •      The literal string **completion**, saying that this style is used by the  completion  sys‐
              tem.   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 nor‐
              mal 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  under‐
              score  and  with  other underscores converted to hyphens.  A `completer' is in overall
              control of how completion is to be performed; `**complete**' is the  simplest,  but  other
              completers  exist to perform related tasks such as correction, or to modify the behav‐
              iour of a later completer.  See the section `Control Functions' below for more  infor‐
              mation.


       •      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  usu‐
              ally 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 func‐
              tion 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_ op‐
       tions.  Finally, the _tag_ is added when the types of completion are known.  For  example,  the
       context name

              **:[completion::complete](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Acomplete/markdown):dvips:option-o-1:files**

       says  that normal completion was attempted as the first argument to the option **-o **of the com‐
       mand **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 re‐
       stricted 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) pattern, and the name of the style itself, which
       must be matched exactly.  The following examples demonstrate that patterns may be loosely de‐
       fined 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 pattern 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)](https://www.chedong.com/phpMan.php/man/zshcompwid/1/markdown))).  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 an‐
       other useful example, see the example in the description of the **file-list **style below.   This
       form  can  be  slow  and  should  be  avoided  for  commonly examined styles such as **menu **and
       **list-rows-first**.

       Note that the order in which styles are _defined_ does not matter; the style mechanism uses the
       most specific possible match for a particular style to determine the set of values.   Strings
       are preferred over patterns (for example, `**:[completion::complete](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Acomplete/markdown):::foo**' is more specific than
       `**:[completion::complete](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Acomplete/markdown):::*'**),  and  longer  patterns  are preferred over the pattern `*****'. See
       [_zmodules_(1)](https://www.chedong.com/phpMan.php/man/zmodules/1/markdown) for details.

       Context patterns that use something other than a wildcard (*****) to match the  middle  parts  of
       the  context  --  the _completer_, _command_, and _argument_ in **:completion:_**function_**:_**completer_**:_**com‐_
       _mand_**:_**argument_**:_**tag_ -- should include all six colons (**:**) explicitly. Without  this,  a  pattern
       such  as  **:completion:*:foo:* **could match **foo **against a component other than the intended one
       (for example, against _completer_ when a match against _command_ was intended).

       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 complet‐
              ing 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 com‐
              pleting 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 con‐
              text name is set

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

### devices
              for names of device special files

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

### directory-stack
              for entries in the directory stack

### displays
              for X display names

### domains
              for network domains

       **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 under‐
              stand other kinds of function

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

       **groups **for names of user groups

### history-words
              for words from the history

       **hosts  **for hostnames

### indexes
              for array indexes

### interfaces
              for network interfaces

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

### keymaps
              for names of zsh keymaps

### keysyms
              for names of X keysyms

### libraries
              for names of system libraries

       **limits **for system limits

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

### mailboxes
              for e-mail folders

### manuals
              for names of manual pages

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

### messages
              used to look up the **format **style for messages

### modifiers
              for names of X modifiers

### modules
              for modules (e.g. **zsh **modules)

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

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

       **names  **for all kinds of names

### newsgroups
              for USENET groups

### nicknames
              for nicknames of NIS maps

### options
              for command options

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

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

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

### parameters
              for names of parameters

### path-directories
              for names of directories found by searching the **cdpath **array when completing arguments
              of **cd **and related builtin commands (compare **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  con‐
              text.   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  other‐
              wise be considered ambiguous).

              When  completing pathnames (where the tag used is `**paths**') this style accepts any num‐
              ber 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 direc‐
              tory 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  de‐
              fault,  filename completion examines all components of a path to see if there are com‐
              pletions 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 be‐
              low) 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 ambigu‐
              ous 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 com‐
              pletion 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 se‐
              quence `**%d**' in the value will be replaced by the description for this  argument.   De‐
              pending  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 com‐
              mand 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 af‐
              ter 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 func‐
              tions to use. The available completer functions are described in the section  `Control
              Functions' below.

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

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

              Here, completion will call the **_complete **completer twice, once  using  `**complete**'  and
              once  using `**complete-foo**' in the _completer_ field of the context.  Normally, using the
              same completer more than once only makes sense when  used  with  the  `_functions_**:_**name_'
              form,  because  otherwise  the  context name will be the same in all calls to the com‐
              pleter; 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 be‐
              come 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 comple‐
              tion 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.

### 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'.

       **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_**:_**de‐_
              _scription_'; 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 fea‐
              tures 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 set‐
              ting 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  **con‐
              tains  a fixed set of directories.  This has the effect of adding the match group `**ex‐**
              **tra directories**' with the given completions.

                     **zstyle ':[completion::complete](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Acomplete/markdown):cd:*' tag-order \**
                       **'named-directories:-mine:extra\ directories**
                       **named-directories:-normal:named\ directories *'**
                     **zstyle ':[completion::complete](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Acomplete/markdown):cd:*:named-directories-mine' \**
                       **fake-always mydir1 mydir2**
                     **zstyle ':[completion::complete](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Acomplete/markdown):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 path‐
              names 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 `**in‐**
              **sert**' or `**list**', indicating that files are to be listed in long format in all  circum‐
              stances,  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  fol‐
              lowed  by  **=_**num_.   If  _num_ is present it gives the maximum number of matches for which
              long listing style will be used.  For example,

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

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

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

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

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

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

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

              The _tag_s of all strings in the value will be offered by **_files **and used  when  looking
              up  other  styles.  Any _tag_s in the same word will be offered at the same time and be‐
              fore 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.  The inclusion of a descrip‐
              tion also gives precedence to associated options such as for completion grouping so it
              can be used where files should be separated.

              For example, to make the **rm **command first complete only names of 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.

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

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

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

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

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

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

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

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

       **format **If  this  is  set  for  the **descriptions **tag, its value is used as a string to display
              above matches in completion lists.  The sequence `**%d**' in this string will be  replaced
              with  a short description of what these matches are.  This string may also contain the
              output attribute sequences understood by **compadd -X **(see [_zshcompwid_(1)](https://www.chedong.com/phpMan.php/man/zshcompwid/1/markdown)).

              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)](https://www.chedong.com/phpMan.php/man/zshmodules/1/markdown).

### 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 com‐
              mand such as **sudo **appears on the command-line. To force the use of, e.g.  **sudo  **or  to
              override  any prefix that might be added due to **gain-privileges**, the **command **style can
              be used with a value that begins with a hyphen.

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

       **global **If this is set to `true' (the default), the **_expand_alias **completer and bindable  com‐
              mand 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 ex‐
              ternal 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  sepa‐
              rately, one can just set:

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

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

              To  display  the  group name in the output, see the **format **style (q.v.)  under the **de‐**
              **scriptions **tag.

### 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 comple‐
              tions 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 comple‐
              tions.  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-ex‐**
              **act **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  gen‐
              eral  context  such  as `**:completion:***'.  This is because it would disallow completion
              of, for example, options multiple times even if the command in  question  accepts  the
              option more than once.

### ignore-parents
              The style is tested without a tag by the function completing pathnames in order to de‐
              termine  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 ex‐
                     ample, 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.

### 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 parame‐
              ter **$fignore**.

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

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

### insert-ids
              When completing process IDs, for example as arguments to the **kill  **and  **wait  **builtins
              the  name  of  a  command  may  be converted to the appropriate process ID.  A problem
              arises when the process name typed is not unique.  By default (or if this style is set
              explicitly to `**menu**') the name will be converted immediately to a set of 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-sections
              This style is used with tags of the form `**manuals._**X_' when completing names  of  manual
              pages.  If  set and the _X_ in the tag name matches the section number of the page being
              completed, the section number is inserted along with the page name. For example, given

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

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

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

              This  is  especially  useful in conjunction with **separate-sections**, as it ensures that
              the page requested of **man **corresponds to the one displayed in the  completion  listing
              when there are multiple pages with the same name (e.g., [**printf(1)](https://www.chedong.com/phpMan.php/man/printf/1/markdown) **and [**printf(3)](https://www.chedong.com/phpMan.php/man/printf/3/markdown)**).

              The default for this style is `false'.

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

              The value may also contain the substrings `**pending**' or `**pending=_**val_'.  In  this  case,
              the  typed character will be inserted instead of starting completion when there is un‐
              processed 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 pa‐
              rameter 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 fi‐
              nal completion.  However, if this style is `true', the completer will start menu  com‐
              pletion  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 al‐
              ready have been set to one of **correct-_**num_ or **approximate-_**num_, where _num_ is the  number
              of errors that were accepted.

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

### 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 re‐
              maining completers may be called.

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

### last-prompt
              This is a more flexible form of the **ALWAYS_LAST_PROMPT **option.  If it is  `true',  the
              completion  system  will  try  to return the cursor to the previous command line after
              displaying a completion list.  It is tested for all tags valid for the current comple‐
              tion, 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.

       **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 specifica‐
              tions.  This mechanism replaces the use of the **ZLS_COLORS **and  **ZLS_COLOURS  **parameters
              described in the section `The zsh/complist Module' in [_zshmodules_(1)](https://www.chedong.com/phpMan.php/man/zshmodules/1/markdown), but the syntax is
              the same.

              If this style is set for the **default **tag, the strings in the value are taken as speci‐
              fications that are to be used everywhere.  If it is set for other tags, the specifica‐
              tions  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 set‐
              ting the style to an empty string (i.e. **''**).

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

### list-grouped
              If  this style is `true' (the default), the completion system will try to make certain
              completion listings more compact by grouping matches.  For example, options  for  com‐
              mands  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  _zshmod‐_
              [_ules_(1)](https://www.chedong.com/phpMan.php/man/ules/1/markdown)).  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-separator
              The  value  of this style is used in completion listing to separate the string to com‐
              plete from a description when possible (e.g. when completing options).  It defaults to
              `**--**' (two hyphens).

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

       **local  **This  is  for  use with functions that complete URLs for which the 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 direc‐
              tory 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 gener‐
              ate  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 over‐
              ride them via the use of an **x: **specification.  The value should be  in  the  form  de‐
              scribed  in  the section `Completion Matching Control' in [_zshcompwid_(1)](https://www.chedong.com/phpMan.php/man/zshcompwid/1/markdown).  For examples
              of this, see the description of the **tag-order **style.

              For notes comparing the use of this and the **matcher-list **style, see under the descrip‐
              tion of the **tag-order **style.

### matcher-list
              This style can be set to a list of match specifications that are to be applied  every‐
              where. Match specifications are described in the section `Completion Matching Control'
              in [_zshcompwid_(1)](https://www.chedong.com/phpMan.php/man/zshcompwid/1/markdown).  The completion system will try them one after another for each com‐
              pleter  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 com‐
              pletion 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 specifica‐
              tions 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 specifica‐
              tions 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  ef‐
              fect,  the  matching  for files is performed case-insensitively in any case.  However,
              any matcher must explicitly specify case-insensitive matching if that is required.

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

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

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

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

              two errors are allowed if no numeric argument is given, but with a numeric argument of
              six (as in `**ESC-6 TAB**'), up to six errors are accepted.  Hence with a value of `**0  nu‐**
              **meric**', 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 ef‐
              fect.   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  to‐
              gether; 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 use‐
              ful 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/com‐**
              **plist **module.  The following values may appear either alongside or instead of the val‐
              ues above.

              If the value contains the string `**select**', menu selection will be started uncondition‐
              ally.

              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  num‐
              ber 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 `**se‐**
              **lect=**' 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)](https://www.chedong.com/phpMan.php/man/zshmodules/1/markdown)
              for a description of interactive mode.  Including the string `**search**'  does  the  same
              for  incremental  search  mode.   To  select  backward incremental search, include the
              string `**search-backward**'.

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

### numbers
              This  is used with the **jobs **tag.  If it is `true', the shell will complete job 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 wid‐
              gets 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 behav‐
              iour  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 gener‐
              ated by a widget which does not do listing.

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

              As another example consider the **_match **completer: with  the  **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 uncon‐
              ditionally.  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 contin‐
              ues  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 comple‐
              tion 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  al‐
              ways added.  Note that the style will be examined with the completer field in the con‐
              text  name  set  to  **correct-_**num_ or **approximate-_**num_, where _num_ is the number of errors
              that were accepted.

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

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

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

       **path   **The function that completes color names uses this style  with  the  **colors  **tag.   The
              value  should be the pathname of a file containing color names in the format of an X11
              **rgb.txt **file.  If the style is not set but this file is found in one of various  stan‐
              dard 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' in‐
              hibits  this  behaviour  for path components up to the **/ **before the cursor; this over‐
              rides 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  **com‐
              pletion tags.

              For  command  options, this means that the initial `**-**', `**+**', or `**--**' must be typed ex‐
              plicitly 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 cir‐
              cumstances.   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 `**$PWD/**':
              note the trailing slash, which allows directories in the pattern to be delimited unam‐
              biguously by including slashes on both sides.  If an ordinary  file  completion  fails
              and  the  word on the command line does not yet have a directory part to its name, the
              style is retrieved using the same tag as for the completion just attempted,  then  the
              elements tested against **$PWD/ **in turn.  If one matches, then the shell reattempts com‐
              pletion  by  prepending the word on the command line with each directory in the expan‐
              sion of ****/*(/) **in turn.  Typically the elements of the style will be set to  restrict
              the  number of directories beneath the current one to a manageable number, for example
              `***/.git/***'.

              For example,

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

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

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

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

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

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

### remove-all-dups
              The **_history_complete_word **bindable command and the **_history **completer use this to de‐
              cide if all duplicate matches should be removed, rather than just  consecutive  dupli‐
              cates.

### 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 `**manuals._**X_', where _X_ is the section number.  When the **group-name **style is also in
              effect, pages from different sections will appear separately.  This style is also used
              similarly with the **words **style when completing words for the dict command.  It  allows
              words from different dictionary databases to be added separately. See also **insert-sec‐**
              **tions**.

              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 out‐
              puts  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  re‐
              moved 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 com‐
              pletion is started, making it easy to select either of them.

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

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

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

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

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

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

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

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

### squeeze-slashes
              If  set  to `true', sequences of slashes in filename paths (for example in `**foo//bar**')
              will be treated as a single slash.  This is the usual behaviour of UNIX  paths.   How‐
              ever,  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 com‐
              pletion  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 glob‐
              bing, 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 ex‐
              pansion.  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  con‐
                     text 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  at‐
                     tempt; 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 dif‐
              ferently 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  ig‐
              nore  all  the completion functions starting with an underscore the first time comple‐
              tion is tried:

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

              On the first attempt, all tags will be offered but the **functions **tag will be  replaced
              by  **functions-non-comp**.   The  **ignored-patterns  **style  is set for this tag to exclude
              functions starting with an 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  condi‐
              tions for the use of particular tags.  For example:

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

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

              If no **tag-order **style has been defined for a  context,  the  strings  `**(|*-)argument-***
              **(|*-)option-*  values**'  and `**options**' plus all tags offered by the completion 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 suit‐
              able 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 di‐
              rectory 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  com‐
              pletion 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 en‐
              tries read from host databases such as NIS and ssh files.  If this  style  is  `true',
              the corresponding IP addresses can be completed as well.  This style is not use in any
              context  where  the  **hosts  **style is set; note also it must be set before the cache of
              host names is generated (typically the first completion attempt).

       **users  **This may be set to a list of usernames to be completed.  If it is not  set  all  user‐
              names  will be completed.  Note that if it is set only that list of users will be com‐
              pleted; 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 com‐
              mands 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 occa‐
              sions.  If this style is `true', the comparison is instead performed only on the  cur‐
              rent  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 ar‐
       guments, 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. nor‐
       mally 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  com‐
       pletion is performed in the context `**:[completion::complete](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Acomplete/markdown):_**..._'.

### _all_matches
              This completer can be used to add a string consisting of all other matches.  As it in‐
              fluences 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)](https://www.chedong.com/phpMan.php/man/zshexpn/1/markdown) 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 possi‐
              ble  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  ac‐
              cepted 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 con‐
              text 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 ex‐
              pensive  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**, **_cor‐**
              **rect **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 com‐
              pletions 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  com‐
              pleted; 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 canonicaliz‐
              ing 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  men‐
              tioned above as possible arguments to the **#compdef **tag.

              Before trying to find a function for a specific context, **_complete **checks if the para‐
              meter  `**compcontext**'  is  set.  Setting `**compcontext**' allows the usual completion dis‐
              patching 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_  indi‐
              cates  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 sys‐
              tem 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 **_approxi‐**
              **mate**, 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 er‐
              rors 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 use‐
              less 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  con‐
              trol 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  be‐
              fore  the completion system is started.  Note also this completer should be called be‐
              fore 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 exten‐
              sions are taken from files in current directory or a directory specified at the begin‐
              ning of the current word. For exact matches, completion continues to allow other  com‐
              pleters  such as **_expand **to expand the pattern. The standard **add-space **and **prefix-hid‐**
              **den **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 com‐
              mand, 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 at‐
              tempted a second time without the word on the line being changed.  On  the  first  at‐
              tempt, 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 simi‐
              larly  but the string on the command line may be a pattern to match against trial com‐
              pletions.  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  com‐
              pletions  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-unambigu‐**
              **ous **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 selec‐
              tion 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_COM‐**
              **PLETE **option and does not work with the other menu  completion  widgets  such  as  **re‐**
              **verse-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  gen‐
              erate  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 af‐
              ter 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](https://www.chedong.com/phpMan.php/perldoc/completion%3A%3Aprefix/markdown):*' completer _complete**

              The  **add-space  **style is also respected.  If it is set to `true' then **_prefix **will in‐
              sert 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;  other‐
              wise,  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  expan‐
              sions  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 gener‐
              ally 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 con‐
              textual completion as the full context has not yet been determined.  Elements  of  the
              array may have one of the following forms:

              **$_**hash_

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

                     __func_  is  the name of a shell function whose name must begin with **_ **but is not
                     otherwise special to the completion system.  The function is  called  with  the
                     trial  word as an argument.  If the word is to be expanded, the function should
                     set the array **reply **to a list of expansions.  Optionally, it can set **REPLY **to a
                     word that will be used as a description for the set of 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 de‐
              fault.  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 con‐
              trolled with the styles **regular**, **global **and **disabled**.

              When used as a bindable command there is one additional feature that can  be  selected
              by setting the **complete **style to `true'.  In this case, if the word is not the name of
              an  alias,  **_expand_alias  **tries to complete the word to a full alias name without ex‐
              panding 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 **com‐
              mand, 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  com‐
              mand  line (which may be blank).  If given a numeric argument _N_, complete the _N_th most
              recently modified file.  Note the completion, if any, is always unique.

       **_next_tags **(**^Xn**)
              This command alters the set of matches used to that for the next tag, or set of  tags,
              either  as given by the **tag-order **style or as set by default; these matches would oth‐
              erwise not be available.  Successive invocations of the command cycle through all pos‐
              sible 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 ar‐
              gument 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 informa‐
              tion 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 _com‐**
              **plete_debug_generic _complete_help_generic**', it will read and  execute  the  keystring
              for  a  generic  widget  as before, but then generate debugging information as done by
              **_complete_debug **for contextual completion.

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

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

              For example, after executing the following:

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

              typing `**C-x :**' followed by the key sequence for a generic widget will cause trace out‐
              put 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 for‐
              mat  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 pa‐
              rameter  **$TAGSFILE  **or **$tagsfile **respectively.  The corresponding completion tags used
              are **etags **and **vtags**, after emacs and vi respectively.

## UTILITY FUNCTIONS
       Descriptions follow for utility functions that may be useful when  writing  completion  func‐
       tions.  If functions are installed in subdirectories, most of these reside in the **Base **subdi‐
       rectory.   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  com‐
       pletions and non-zero if no matching completions could be added.

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

       **_all_labels **[ **-x **] [ **-12VJ **] _tag_ _name_ _descr_ [ _command_ _arg_ ... ]
              This is a convenient interface to the **_next_label  **function  below,  implementing  the
              loop  shown  in  the **_next_label **example.  The _command_ and its arguments are called to
              generate the matches.  The options stored in the parameter _name_ will automatically  be
              inserted  into  the _arg_s passed to the _command_.  Normally, they are put directly after
              the _command_, but if one of the _arg_s is a single hyphen, they are inserted directly be‐
              fore 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  com‐
              mand or by a call to one of the utility functions.

              For example:

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

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

       **_alternative **[ **-O _**name_ ] [ **-C _**name_ ] _spec_ ...
              This function is useful in simple cases where multiple  tags  are  available.   Essen‐
              tially it implements a loop like the one described for the **_tags **function below.

              The  tags  to  use and the action to perform if a tag is requested are described using
              the _spec_s which are of the form: `_tag_**:_**descr_**:_**action_'.  The _tag_s are offered using **_tags**
              and if the tag is requested, the _action_ is executed with the given description  _descr_.
              The  _action_s are those accepted by the **_arguments **function (described below), with the
              following exceptions:
              •      The `**->_**state_' and `**=_**..._' forms are not supported.


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


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

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

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

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

              The  option `**-O _**name_' is used in the same way as by the **_arguments **function.  In other
              words, the elements of the _name_ array will be passed to **compadd **when executing an  ac‐
              tion.

              Like **_tags **this function supports the **-C **option to give a different name for the argu‐
              ment 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 com‐
              mand 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  op‐
              tions  are  followed by _spec_s that describe options and arguments of the analyzed com‐
              mand.  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-let‐
                     ter  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 seg‐
                     ment entitled `Deriving _spec_ forms from the help output'.

              **-w     **In combination with **-s**, allow option stacking even if one or more  of  the  op‐
                     tions  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 subse‐
                     quent 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  de‐
                     pends  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 ac‐
                     tion.

              **-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  ar‐
                     gument,  but  ignoring  all strings starting with a hyphen even if they are not
                     described by one of the _optspec_s, the form is `**-A "-*"**'.

              **-O _**name_
                     Pass the elements of the array _name_ as arguments to functions called to execute
                     _action_s.  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:|=***

              **-0     **When populating values of the `**opt_args**' associative array, don't backslash-es‐
                     cape  colons and backslashes and use NUL rather than colon for joining multiple
                     values. This option is described in more detail below, under the heading _specs:_
                     _actions._

              _specs:_ _overview_

              Each of the following forms is a _spec_ describing individual sets of options  or  argu‐
              ments 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 posi‐
                     tion (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  pro‐
                     vided.  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 argu‐
                     ments to the option; if it is not present, the option is assumed to take no ar‐
                     guments.

                     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  op‐
                            tion 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  op‐
                            tion (if any) must follow as a _separate_ word directly after the option.

                            Either  of `**-+_**optname_' and `**+-_**optname_' can be used to specify that **-_**opt‐_
                            _name_ 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 com‐
                            pleted option and argument will look like `**-foo_**arg_'.

                     **-_**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 `**-foo_**arg_' or `**-foo _**arg_'.

                     **-_**optname_**=**
                            The argument may appear as the next word, or in same word as the  option
                            name  provided that it is separated from it by an equals sign, for exam‐
                            ple `**-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 char‐
                     acter 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  ordi‐
                            nary  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  com‐
                            pleted  as  described  by the _action_; otherwise, all the words up to and
                            including a word matching the _pattern_ are to be completed using the  _ac‐_
                            _tion_.

                            Multiple  colons are treated as for the `***:_**..._' forms for ordinary argu‐
                            ments:  when the _message_ is preceded by two colons,  the  **words  **special
                            array  and  the **CURRENT **special parameter are modified during the execu‐
                            tion 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  argu‐
              ments  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  op‐
              tions  **-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  argu‐
              ment  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 _action_s will be called with the elements of the  array
              named  by  the  `**-O _**name_' option as arguments.  This can be used, for example, to pass
              the same set of options for the **compadd **builtin to all _action_s.

              The forms for _action_ are as follows.

               (single unquoted space)
                     This is useful where an argument is required but it is not possible  or  desir‐
                     able  to generate matches for it.  The _message_ will be displayed but no comple‐
                     tions 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 _string_s for which an action is to be performed.  The elements of the ar‐
                     ray  **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, _ar‐
                     guments returns status zero if it was able to add matches and  non-zero  other‐
                     wise. However, if the **-R **option is given, **_arguments **will instead return a sta‐
                     tus of 300 to indicate that **$state **is to be handled.

                     In addition to **$state **and **$state_descr**, **_arguments **also sets the global parame‐
                     ters  `**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 propa‐
                     gating 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 re‐
                     stricted range; it is necessary to use this trick to insert an appropriate com‐
                     mand 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 en‐
                     sure 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, typ‐
                     ically 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 argu‐
              ments from the command line, i.e. the words from the command line  after  the  command
              name excluding all options and their arguments.  Options are stored in the associative
              array  `**opt_args**' with option names as keys and their arguments as the values.  By de‐
              fault, all colons and backslashes in the value are escaped with backslashes, and if an
              option has multiple arguments (for example, when using an _optspec_ of the  form  `***_**opt‐_
              _spec_'),  they  are  joined  with  (unescaped)  colons.   However, if the **-0 **option was
              passed, no backslash escaping is performed, and multiple values are  joined  with  NUL
              bytes.   For  example,  after  `**zsh  -o  foo:foo -o bar:bar -o <TAB>**', the contents of
              `**opt_args**' would be

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

              by default, and

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

              if **_arguments **had been called with the **-0 **option.

              The parameter `**context**' is set when returning to the calling 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  op‐
              tion _-opt_, or a string of the form `**argument-_**n_' for the _n_'th argument.  For `rest' ar‐
              guments, that is those in the list at the end not handled by position, _n_ is the string
              `**rest**'.   For example, when completing the argument of the **-o **option, the name is `**op‐**
              **tion-o-1**', while for the second normal (non-option-) argument it is `**argument-2**'.

              Furthermore, during the evaluation of the _action_ the context name  in  the  **curcontext**
              parameter  is  altered to append the same string that is stored in the **context **parame‐
              ter.

              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 con‐
              text.  Here it (and not the **context **array) should be made local to the  calling  func‐
              tion 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 ref‐
              erenced 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 `**opera‐**
              **tion--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  sepa‐
              rated  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 ex‐
              ample:

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

              This defines two sets.  When the command line contains the option `**-c**', the  `**-d**'  op‐
              tion  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  pre‐
              ceding 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 op‐
              tion  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 pro‐
              vide  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 de‐
              scription 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  `**--di‐**
              **rectory**', though not after `**-C**'.

              Note  also  that **_arguments **tries to find out automatically if the argument for an op‐
              tion 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  lo‐
              cale  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  com‐
              mand 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 op‐
              tion 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 `**--en‐**
              **able-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 treat‐
              ment 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](https://www.chedong.com/phpMan.php/perldoc/files%3A%3Aresolution/markdown):(300 600)' \**
                                **':postscript file:_files -g \*.\(ps\|eps\)' \**
                                **'*:page number:'**

              This describes three options: `**-l**', `**-format**', and `**-copy**'.  The first takes one argu‐
              ment 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  argu‐
              ments.  The first is mandatory and will be completed as a filename.  The second is op‐
              tional  (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  de‐
              scribes  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_ _number_' but does not offer completions.

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

              Example:

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

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

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

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

              By default, the command is run in an environment where all the locale categories  (ex‐
              cept  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  host‐
              names  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 com‐
              pletions  should be generated (presumably not one of the _field_s for which the value is
              known).

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

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

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

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

       **_command_names **[ **-e **| **- **]
              This function completes words that are valid at command position:  names  of  aliases,
              builtins,  hashed  commands, functions, and so on.  With the **-e **flag, only hashed com‐
              mands 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 ex‐
              ported to the environment. Typical usage would be `**$(_comp_locale; _**command_ ...**)**'.

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

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

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


       **_describe **[**-12JVx**] [ **-oO **| **-t _**tag_ ] _descr_ _name1_ [ _name2_ ] [ _opt_ ... ]
                 [ **-- _**name1_ [ _name2_ ] [ _opt_ ... ] ... ]
              This function associates completions with descriptions.  Multiple groups separated  by
              **-- **can be supplied, potentially with different completion options _opt_s.

              The  _descr_  is  taken as a string to display above the matches if the **format **style for
              the **descriptions **tag is set.  This is followed by one or two names of arrays  followed
              by options to pass to **compadd**.  The array _name1_ contains the possible completions with
              their  descriptions  in the form `_completion_**:_**description_'.  Any literal colons in _com‐_
              _pletion_ 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 pos‐
              sible completions instead of the _completion_ strings from _name1_.  The  completion  list
              will retain the descriptions from _name1_.  Finally, a set of completion options can ap‐
              pear.

              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 comple‐
              tions and if the descriptions should be shown.  Without the `**-o**' option, only the **ver‐**
              **bose **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 **pre‐**
              **fix-needed **style.

              With the **-t **option a _tag_ can be specified.  The default is `**values**' or, if the **-o  **op‐
              tion is given, `**options**'.

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

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

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

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

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

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

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

              If  **_description **is called with more than three arguments, the additional _spec_s should
              be of the form `_char_**:_**str_'.  These supply escape sequence replacements for  the  **format**
              style: every appearance of `**%_**char_' will be replaced by _string_.  If no additional _spec_s
              are  given  but the description in _descr_ conforms to a common form then further escape
              sequences are set for elements of that description.  These elements  correspond  to  a
              default  value  (`**%o**'), the units (`**%m**') range of acceptable values (`**%r**') and the re‐
              maining initial part of the description (`**%h**').  The form the description  takes  con‐
              sists of specifying the units and range in parentheses and the default value in square
              brackets, for example:

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

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

              If the **-x **option is given, the description will be passed to **compadd **using the **-x  **op‐
              tion  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 ar‐
              ray.   Hence  it is possible for the completion group to be unsorted by giving the op‐
              tion `**-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  de‐
              scribed  above for **compdef**) given as _string_s.  The first completion function to be de‐
              fined 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 **$service **to the _string_ being tried, and sets the _con‐_
              _text/command_ field (the fourth) of the **$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 com‐
                     pleted.

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

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

### _gnu_generic
              This function is a simple wrapper around the **_arguments **function described above.   It
              can  be  used  to determine automatically the long options understood by commands that
              produce a list when passed the option `**--help**'.  It  is  intended  to  be  used  as  a
              top-level completion function in its own right.  For example, to enable option comple‐
              tion 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 in‐
              tended to be used in the _action_ for the specifications passed to **_arguments **and  simi‐
              lar 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  conven‐
              tions 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  op‐
              tions  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 gen‐
              erated.  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 ar‐
              gument list which already contains an expanded description.   Note  that  this  option
              does not disable the `**%**'-sequence parsing done by **compadd**.

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

              The second **-e **form gives a description for completions with the tag _tag_  to  be  shown
              even  if  there are no matches for that tag.  This form is called by **_arguments **in the
              event that there is no action for an option specification.  The tag can be omitted and
              if so the tag is taken from the parameter **$curtag**; this is maintained by  the  comple‐
              tion  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 ar‐
              ray 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 ar‐
              ray.  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 mul‐
              tiple 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 **com‐**
              **padd **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 **func‐
              tion.  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_la‐**
              **bel**.

              The  _option_s  given  after the _descr_ are set in the parameter given by _name_, and hence
              are to be passed to **compadd **or whatever function is called to add the matches.

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

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

       **_normal **[ **-P **| **-p _**precommand_ ]
              This  is  the  standard function called to handle completion outside any special **-_**con‐_
              _text_**-**.  It is called both to complete the command word and also the  arguments  for  a
              command.  In the second case, **_normal **looks for a special completion for that 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 **_precom‐**
              **mand**, which completes after precommand specifiers such as  **nohup**,  removes  the  first
              word  from  the  **words **array, decrements the **CURRENT **parameter, then calls `**_normal -p**
              **$service**'.  The effect is that `**nohup _**cmd_ _..._' is treated in  the  same  way  as  `_cmd_
              _..._'.

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

              **-p _**precommand_
                     Append  _precommand_  to  the  list of precommands. This option should be used in
                     nearly all cases in which **-P **is not applicable.

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

       **_numbers **[ _option_ ... ] [ _description_ ] [ _suffix_ ... ]
              This  can  be  used where a number is followed by a suffix to indicate the units.  The
              unit suffixes are completed and can also be included in the description used when com‐
              pletion is invoked for the preceding number.

              In addition to common **compadd **options, **_numbers **accepts the following options:

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

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

              **-l _**min_ Specify the lowest possible value for the number.

              **-m _**max_ Specify the highest possible value for the number.

              **-d _**default_
                     Specify the default value.

              **-N     **Allow negative numbers.  This is implied if the range includes a negative.

              **-f     **Allow decimal numbers.

              Where a particular suffix represents the default units for a number, it should be pre‐
              fixed with a colon.  Additionally, suffixes can be followed by a colon and a  descrip‐
              tion.   So for example, the following allows the age of something to be specified, ei‐
              ther in seconds or with an optional suffix with a longer unit of time:

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

              It is typically helpful for units to be presented in  order  of  magnitude  when  com‐
              pleted.  To facilitate this, the order in which they are given is preserved.

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

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

### _options
              This can be used to complete the names of shell options.  It provides a matcher speci‐
              fication that ignores a leading `**no**', ignores underscores and allows  upper-case  let‐
              ters  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  specifica‐
              tion 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  set‐
              tings in effect before the completion widget locally sets the options it needs.  Hence
              these functions are not generally used by the completion system.

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

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

              All other arguments are passed to the **compadd **builtin.

### _path_files
              This  function is used throughout the completion system to complete filenames.  It al‐
              lows completion of partial paths.  For example, the string `**/u/i/s/sig**'  may  be  com‐
              pleted 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  pa‐
                     rameter,  a  literal list of paths enclosed in parentheses or an absolute path‐
                     name.

              **-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 **com‐**
              **padd**: `**-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 argu‐
              ments _label_**=_**pattern_; if the output of `_command_ _arg_ ...' contains _pattern_,  then  _label_
              is  selected as the label for the command variant.  If none of the patterns match, the
              final command label is selected and status 1 is returned.

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

              If the `**-r _**name_' is given, the _label_ picked is stored in the parameter named _name_.

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

       **_regex_arguments _**name_ _spec_ ...
              This  function  generates  a completion function _name_ which matches the specifications
              _spec_s, a set of regular expressions as described below.   After  running  **_regex_argu‐**
              **ments**,  the  function _name_ should be called as a normal completion function.  The pat‐
              tern to be matched is given by the contents of the **words **array up to the current  cur‐
              sor 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  remain‐
              ing  word  and any _action_s for the corresponding patterns are executed.  In this case,
              nothing is stripped from the command line string.  The order of evaluation of the  _ac‐_
              _tion_s  can be determined by the **tag-order **style; the various formats supported by **_al‐**
              **ternative **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  ex‐
                     amined.

                     The  argument starting with **: **is used in the same manner as an argument to **_al‐**
                     **ternative**.

                     A component is used as follows: _pattern_ is tested to see if the  component  al‐
                     ready 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 _action_s of the current and previ‐
                     ously matched patterns are ignored even if the following `_pattern_' matches  the
                     empty string.

              **( _**spec_ **)**
                     Parentheses  may be used to groups _spec_s; note each parenthesis is a single ar‐
                     gument to **_regex_arguments**.

              _spec_ **# **This allows any number of repetitions of _spec_.

              _spec_ _spec_
                     The two _spec_s are to be matched one after the other as described above.

              _spec_ **| _**spec_
                     Either of the two _spec_s can be matched.

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

              Examples:

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

              This  generates  a function **_tst **that completes **aaa **as its only argument.  The _tag_ and
              _description_ for the action have been omitted for brevity (this works but is not recom‐
              mended in normal use).  The first component matches the command word, which  is  arbi‐
              trary;  the second matches  any argument.  As the argument is also arbitrary, any fol‐
              lowing 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  ar‐
              guments  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 _descrip‐_
              _tion_ 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 com‐
              pleted are themselves to be completed.  It will be evaluated in order to  avoid  prob‐
              lems with quoting.  This means that typically it contains a reference to an array con‐
              taining 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 ar‐
              guments 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 op‐
              tions.

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

              See **_store_cache **below for more details.

### _sep_parts
              This function is passed alternating arrays and separators as  arguments.   The  arrays
              specify  completions  for parts of strings to be separated by the separators.  The ar‐
              rays 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  appropri‐
              ately  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  opera‐
              tions  are  stored in parameters; this function then dumps the values of those parame‐
              ters to a file.  The data can then be  retrieved  quickly  from  that  file  via  **_re‐**
              **trieve_cache**, even in different instances of the shell.

              The  _cache_identifier_ specifies the file which the data should be dumped to.  The file
              is stored in a directory specified by the **cache-path **style which defaults to **~/.zcomp‐**
              **cache**.  The remaining _param_s arguments are the parameters to dump to the file.

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

              The completion function may avoid calling **_retrieve_cache **when it already has the com‐
              pletion data available as parameters.  However, in that case it should call **_cache_in‐**
              **valid **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 comple‐
              tions in the current context.  These tags are stored internally and  sorted  by  using
              the **tag-order **style.

              Next,  **_tags **is called repeatedly without arguments from the same completion 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 other‐
              wise.   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  re‐
              stored  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 com‐
              mand-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 argu‐
              ment is used as the character that separates multiple values.  This character is auto‐
              matically 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 comple‐
              tion using **_arguments**.  If this option is not present, only a  single  value  will  be
              completed per word.

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

              The first non-option argument, _desc_, is used as a string to print as a description be‐
              fore listing the values.

              All  other arguments describe the possible values and their arguments in the same for‐
              mat 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 de‐
              scribed 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 func‐
              tion  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 val‐
              ues 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 pa‐
              rameter **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 genera‐
              tion of matches, is carried out automatically by **_wanted**.

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

                     **local expl**
                     **_wanted tag expl 'description' \**
                         **compadd -- _**match1_ _match2_**...**

              See  also  the use of **_wanted **in the example function in the subsection `Dynamic named
              directories' in [_zshexpn_(1)](https://www.chedong.com/phpMan.php/man/zshexpn/1/markdown).

              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 argu‐
              ment 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)](https://www.chedong.com/phpMan.php/man/zshzle/1/markdown)).
              The  _pattern_, if present, is matched against values of the **$widgets **special parameter,
              documented in the section `The zsh/zleparameter Module' in [_zshmodules_(1)](https://www.chedong.com/phpMan.php/man/zshmodules/1/markdown).

## 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  prefer‐
              ences  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  af‐
       ter  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  **Comple‐**
       **tion **directory.  They may have been installed in the same structure, or into one single func‐
       tion  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  direc‐
       tory 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 de‐
              cide 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  **directo‐
              ries, as well as the **X **directory, may be useful on your system.

zsh 5.9                                     May 14, 2022                               [_ZSHCOMPSYS_(1)](https://www.chedong.com/phpMan.php/man/ZSHCOMPSYS/1/markdown)
