path: root/assets/info/zsh.info-3

This is zsh.info, produced by makeinfo version 4.8 from ./zsh.texi.

INFO-DIR-SECTION Utilities
START-INFO-DIR-ENTRY
* ZSH: (zsh).                     The Z Shell Manual.
END-INFO-DIR-ENTRY


File: zsh.info,  Node: History Control,  Next: Modifying Text,  Prev: Movement,  Up: Zle Widgets

18.6.2 History Control
----------------------


beginning-of-buffer-or-history (ESC-<) (gg) (unbound)
     Move to the beginning of the buffer, or if already there, move to
     the first event in the history list.

beginning-of-line-hist
     Move to the beginning of the line.  If already at the beginning of
     the buffer, move to the previous history line.

beginning-of-history
     Move to the first event in the history list.

down-line-or-history (^N ESC-[B) (j) (ESC-[B)
     Move down a line in the buffer, or if already at the bottom line,
     move to the next event in the history list.

vi-down-line-or-history (unbound) (+) (unbound)
     Move down a line in the buffer, or if already at the bottom line,
     move to the next event in the history list.  Then move to the
     first non-blank character on the line.

down-line-or-search
     Move down a line in the buffer, or if already at the bottom line,
     search forward in the history for a line beginning with the first
     word in the buffer.

     If called from a function by the zle command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

down-history (unbound) (^N) (unbound)
     Move to the next event in the history list.

history-beginning-search-backward
     Search backward in the history for a line beginning with the
     current line up to the cursor.  This leaves the cursor in its
     original position.

end-of-buffer-or-history (ESC->) (unbound) (unbound)
     Move to the end of the buffer, or if already there, move to the
     last event in the history list.

end-of-line-hist
     Move to the end of the line.  If already at the end of the buffer,
     move to the next history line.

end-of-history
     Move to the last event in the history list.

vi-fetch-history (unbound) (G) (unbound)
     Fetch the history line specified by the numeric argument.  This
     defaults to the current history line (i.e. the one that isn't
     history yet).

history-incremental-search-backward (^R ^Xr) (unbound) (unbound)
     Search backward incrementally for a specified string.  The search
     is case-insensitive if the search string does not have uppercase
     letters and no numeric argument was given.  The string may begin
     with `^' to anchor the search to the beginning of the line.  When
     called from a user-defined function returns the following
     statuses: 0, if the search succeeded; 1, if the search failed; 2,
     if the search term was a bad pattern; 3, if the search was aborted
     by the send-break command.

     A restricted set of editing functions is available in the
     mini-buffer.  Keys are looked up in the special isearch keymap,
     and if not found there in the main keymap (note that by default
     the isearch keymap is empty).  An interrupt signal, as defined by
     the stty setting, will stop the search and go back to the original
     line.  An undefined key will have the same effect.  Note that the
     following always perform the same task within incremental searches
     and cannot be replaced by user defined widgets, nor can the set of
     functions be extended.  The supported functions are:


    accept-and-hold
    accept-and-infer-next-history
    accept-line
    accept-line-and-down-history
          Perform the usual function after exiting incremental search.
          The command line displayed is executed.

    backward-delete-char
    vi-backward-delete-char
          Back up one place in the search history.  If the search has
          been repeated this does not immediately erase a character in
          the minibuffer.

    accept-search
          Exit incremental search, retaining the command line but
          performing no further action.  Note that this function is not
          bound by default and has no effect outside incremental search.

    backward-delete-word
    backward-kill-word
    vi-backward-kill-word
          Back up one character in the minibuffer; if multiple searches
          have been performed since the character was inserted the
          search history is rewound to the point just before the
          character was entered.  Hence this has the effect of repeating
          backward-delete-char.

    clear-screen
          Clear the screen, remaining in incremental search mode.

    history-incremental-search-backward
          Find the next occurrence of the contents of the mini-buffer.
          If the mini-buffer is empty, the most recent previously used
          search string is reinstated.

    history-incremental-search-forward
          Invert the sense of the search.

    magic-space
          Inserts a non-magical space.

    quoted-insert
    vi-quoted-insert
          Quote the character to insert into the minibuffer.

    redisplay
          Redisplay the command line, remaining in incremental search
          mode.

    vi-cmd-mode
          Select the `vicmd' keymap; the `main' keymap (insert mode)
          will be selected initially.

          In addition, the modifications that were made while in vi
          insert mode are merged to form a single undo event.

    vi-repeat-search
    vi-rev-repeat-search
          Repeat the search.  The direction of the search is indicated
          in the mini-buffer.


     Any character that is not bound to one of the above functions, or
     self-insert or self-insert-unmeta, will cause the mode to be
     exited.  The character is then looked up and executed in the
     keymap in effect at that point.

     When called from a widget function by the zle command, the
     incremental search commands can take a string argument.  This will
     be treated as a string of keys, as for arguments to the bindkey
     command, and used as initial input for the command.  Any
     characters in the string which are unused by the incremental
     search will be silently ignored.  For example,


          zle history-incremental-search-backward forceps

     will search backwards for forceps, leaving the minibuffer
     containing the string `forceps'.

history-incremental-search-forward (^S ^Xs) (unbound) (unbound)
     Search forward incrementally for a specified string.  The search is
     case-insensitive if the search string does not have uppercase
     letters and no numeric argument was given.  The string may begin
     with `^' to anchor the search to the beginning of the line.  The
     functions available in the mini-buffer are the same as for
     history-incremental-search-backward.

history-incremental-pattern-search-backward
history-incremental-pattern-search-forward
     These widgets behave similarly to the corresponding widgets with
     no -pattern, but the search string typed by the user is treated as
     a pattern, respecting the current settings of the various options
     affecting pattern matching.  See *Note Filename Generation:: for a
     description of patterns.  If no numeric argument was given
     lowercase letters in the search string may match uppercase letters
     in the history.  The string may begin with `^' to anchor the
     search to the beginning of the line.

     The prompt changes to indicate an invalid pattern; this may simply
     indicate the pattern is not yet complete.

     Note that only non-overlapping matches are reported, so an
     expression with wildcards may return fewer matches on a line than
     are visible by inspection.

history-search-backward (ESC-P ESC-p) (unbound) (unbound)
     Search backward in the history for a line beginning with the first
     word in the buffer.

     If called from a function by the zle command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

vi-history-search-backward (unbound) (/) (unbound)
     Search backward in the history for a specified string.  The string
     may begin with `^' to anchor the search to the beginning of the
     line.

     A restricted set of editing functions is available in the
     mini-buffer.  An interrupt signal, as defined by the stty setting,
     will stop the search.  The functions available in the mini-buffer
     are: accept-line, backward-delete-char, vi-backward-delete-char,
     backward-kill-word, vi-backward-kill-word, clear-screen, redisplay,
     quoted-insert and vi-quoted-insert.

     vi-cmd-mode is treated the same as accept-line, and magic-space is
     treated as a space.  Any other character that is not bound to
     self-insert or self-insert-unmeta will beep and be ignored. If the
     function is called from vi command mode, the bindings of the
     current insert mode will be used.

     If called from a function by the zle command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

history-search-forward (ESC-N ESC-n) (unbound) (unbound)
     Search forward in the history for a line beginning with the first
     word in the buffer.

     If called from a function by the zle command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

vi-history-search-forward (unbound) (?) (unbound)
     Search forward in the history for a specified string.  The string
     may begin with `^' to anchor the search to the beginning of the
     line. The functions available in the mini-buffer are the same as
     for vi-history-search-backward.  Argument handling is also the same
     as for that command.

infer-next-history (^X^N) (unbound) (unbound)
     Search in the history list for a line matching the current one and
     fetch the event following it.

insert-last-word (ESC-_ ESC-.) (unbound) (unbound)
     Insert the last word from the previous history event at the cursor
     position.  If a positive numeric argument is given, insert that
     word from the end of the previous history event.  If the argument
     is zero or negative insert that word from the left (zero inserts
     the previous command word).  Repeating this command replaces the
     word just inserted with the last word from the history event prior
     to the one just used; numeric arguments can be used in the same
     way to pick a word from that event.

     When called from a shell function invoked from a user-defined
     widget, the command can take one to three arguments.  The first
     argument specifies a history offset which applies to successive
     calls to this widget: if it is -1, the default behaviour is used,
     while if it is 1, successive calls will move forwards through the
     history.  The value 0 can be used to indicate that the history
     line examined by the previous execution of the command will be
     reexamined.  Note that negative numbers should be preceded by a
     `--' argument to avoid confusing them with options.

     If two arguments are given, the second specifies the word on the
     command line in normal array index notation (as a more natural
     alternative to the numeric argument).  Hence 1 is the first word,
     and -1 (the default) is the last word.

     If a third argument is given, its value is ignored, but it is used
     to signify that the history offset is relative to the current
     history line, rather than the one remembered after the previous
     invocations of insert-last-word.

     For example, the default behaviour of the command corresponds to


          zle insert-last-word -- -1 -1

     while the command


          zle insert-last-word -- -1 1 -

     always copies the first word of the line in the history
     immediately before the line being edited.  This has the side
     effect that later invocations of the widget will be relative to
     that line.

vi-repeat-search (unbound) (n) (unbound)
     Repeat the last vi history search.

vi-rev-repeat-search (unbound) (N) (unbound)
     Repeat the last vi history search, but in reverse.

up-line-or-history (^P ESC-[A) (k) (ESC-[A)
     Move up a line in the buffer, or if already at the top line, move
     to the previous event in the history list.

vi-up-line-or-history (unbound) (-) (unbound)
     Move up a line in the buffer, or if already at the top line, move
     to the previous event in the history list.  Then move to the first
     non-blank character on the line.

up-line-or-search
     Move up a line in the buffer, or if already at the top line,
     search backward in the history for a line beginning with the first
     word in the buffer.

     If called from a function by the zle command with arguments, the
     first argument is taken as the string for which to search, rather
     than the first word in the buffer.

up-history (unbound) (^P) (unbound)
     Move to the previous event in the history list.

history-beginning-search-forward
     Search forward in the history for a line beginning with the current
     line up to the cursor.  This leaves the cursor in its original
     position.

set-local-history
     By default, history movement commands visit the imported lines as
     well as the local lines. This widget lets you toggle this on and
     off, or set it with the numeric argument. Zero for both local and
     imported lines and nonzero for only local lines.



File: zsh.info,  Node: Modifying Text,  Next: Arguments,  Prev: History Control,  Up: Zle Widgets

18.6.3 Modifying Text
---------------------


vi-add-eol (unbound) (A) (unbound)
     Move to the end of the line and enter insert mode.

vi-add-next (unbound) (a) (unbound)
     Enter insert mode after the current cursor position, without
     changing lines.

backward-delete-char (^H ^?) (unbound) (unbound)
     Delete the character behind the cursor.

vi-backward-delete-char (unbound) (X) (^H)
     Delete the character behind the cursor, without changing lines.
     If in insert mode, this won't delete past the point where insert
     mode was last entered.

backward-delete-word
     Delete the word behind the cursor.

backward-kill-line
     Kill from the beginning of the line to the cursor position.

backward-kill-word (^W ESC-^H ESC-^?) (unbound) (unbound)
     Kill the word behind the cursor.

vi-backward-kill-word (unbound) (unbound) (^W)
     Kill the word behind the cursor, without going past the point
     where insert mode was last entered.

capitalize-word (ESC-C ESC-c) (unbound) (unbound)
     Capitalize the current word and move past it.

vi-change (unbound) (c) (unbound)
     Read a movement command from the keyboard, and kill from the
     cursor position to the endpoint of the movement.  Then enter
     insert mode.  If the command is vi-change, change the current line.

     For compatibility with vi, if the command is vi-forward-word or
     vi-forward-blank-word, the whitespace after the word is not
     included. If you prefer the more consistent behaviour with the
     whitespace included use the following key binding:


          bindkey -a -s cw dwi

vi-change-eol (unbound) (C) (unbound)
     Kill to the end of the line and enter insert mode.

vi-change-whole-line (unbound) (S) (unbound)
     Kill the current line and enter insert mode.

copy-region-as-kill (ESC-W ESC-w) (unbound) (unbound)
     Copy the area from the cursor to the mark to the kill buffer.

     If called from a ZLE widget function in the form `zle
     copy-region-as-kill STRING' then STRING will be taken as the text
     to copy to the kill buffer.  The cursor, the mark and the text on
     the command line are not used in this case.

copy-prev-word (ESC-^_) (unbound) (unbound)
     Duplicate the word to the left of the cursor.

copy-prev-shell-word
     Like copy-prev-word, but the word is found by using shell parsing,
     whereas copy-prev-word looks for blanks. This makes a difference
     when the word is quoted and contains spaces.

vi-delete (unbound) (d) (unbound)
     Read a movement command from the keyboard, and kill from the
     cursor position to the endpoint of the movement.  If the command
     is vi-delete, kill the current line.

delete-char
     Delete the character under the cursor.

vi-delete-char (unbound) (x) (unbound)
     Delete the character under the cursor, without going past the end
     of the line.

delete-word
     Delete the current word.

down-case-word (ESC-L ESC-l) (unbound) (unbound)
     Convert the current word to all lowercase and move past it.

vi-down-case (unbound) (gu) (unbound)
     Read a movement command from the keyboard, and convert all
     characters from the cursor position to the endpoint of the
     movement to lowercase.  If the movement command is vi-down-case,
     swap the case of all characters on the current line.

kill-word (ESC-D ESC-d) (unbound) (unbound)
     Kill the current word.

gosmacs-transpose-chars
     Exchange the two characters behind the cursor.

vi-indent (unbound) (>) (unbound)
     Indent a number of lines.

vi-insert (unbound) (i) (unbound)
     Enter insert mode.

vi-insert-bol (unbound) (I) (unbound)
     Move to the first non-blank character on the line and enter insert
     mode.

vi-join (^X^J) (J) (unbound)
     Join the current line with the next one.

kill-line (^K) (unbound) (unbound)
     Kill from the cursor to the end of the line.  If already on the
     end of the line, kill the newline character.

vi-kill-line (unbound) (unbound) (^U)
     Kill from the cursor back to wherever insert mode was last entered.

vi-kill-eol (unbound) (D) (unbound)
     Kill from the cursor to the end of the line.

kill-region
     Kill from the cursor to the mark.

kill-buffer (^X^K) (unbound) (unbound)
     Kill the entire buffer.

kill-whole-line (^U) (unbound) (unbound)
     Kill the current line.

vi-match-bracket (^X^B) (%) (unbound)
     Move to the bracket character (one of {}, () or []) that matches
     the one under the cursor.  If the cursor is not on a bracket
     character, move forward without going past the end of the line to
     find one, and then go to the matching bracket.

vi-open-line-above (unbound) (O) (unbound)
     Open a line above the cursor and enter insert mode.

vi-open-line-below (unbound) (o) (unbound)
     Open a line below the cursor and enter insert mode.

vi-oper-swap-case (unbound) (g~) (unbound)
     Read a movement command from the keyboard, and swap the case of
     all characters from the cursor position to the endpoint of the
     movement.  If the movement command is vi-oper-swap-case, swap the
     case of all characters on the current line.

overwrite-mode (^X^O) (unbound) (unbound)
     Toggle between overwrite mode and insert mode.

vi-put-before (unbound) (P) (unbound)
     Insert the contents of the kill buffer before the cursor.  If the
     kill buffer contains a sequence of lines (as opposed to
     characters), paste it above the current line.

vi-put-after (unbound) (p) (unbound)
     Insert the contents of the kill buffer after the cursor.  If the
     kill buffer contains a sequence of lines (as opposed to
     characters), paste it below the current line.

put-replace-selection (unbound) (unbound) (unbound)
     Replace the contents of the current region or selection with the
     contents of the kill buffer. If the kill buffer contains a
     sequence of lines (as opposed to characters), the current line
     will be split by the pasted lines.

quoted-insert (^V) (unbound) (unbound)
     Insert the next character typed into the buffer literally.  An
     interrupt character will not be inserted.

vi-quoted-insert (unbound) (unbound) (^Q ^V)
     Display a `^' at the cursor position, and insert the next
     character typed into the buffer literally.  An interrupt character
     will not be inserted.

quote-line (ESC-') (unbound) (unbound)
     Quote the current line; that is, put a `'' character at the
     beginning and the end, and convert all `'' characters to `'\'''.

quote-region (ESC-") (unbound) (unbound)
     Quote the region from the cursor to the mark.

vi-replace (unbound) (R) (unbound)
     Enter overwrite mode.

vi-repeat-change (unbound) (.) (unbound)
     Repeat the last vi mode text modification.  If a count was used
     with the modification, it is remembered.  If a count is given to
     this command, it overrides the remembered count, and is remembered
     for future uses of this command.  The cut buffer specification is
     similarly remembered.

vi-replace-chars (unbound) (r) (unbound)
     Replace the character under the cursor with a character read from
     the keyboard.

self-insert (printable characters) (unbound) (printable characters and some control characters)
     Insert a character into the buffer at the cursor position.

self-insert-unmeta (ESC-^I ESC-^J ESC-^M) (unbound) (unbound)
     Insert a character into the buffer after stripping the meta bit
     and converting ^M to ^J.

vi-substitute (unbound) (s) (unbound)
     Substitute the next character(s).

vi-swap-case (unbound) (~) (unbound)
     Swap the case of the character under the cursor and move past it.

transpose-chars (^T) (unbound) (unbound)
     Exchange the two characters to the left of the cursor if at end of
     line, else exchange the character under the cursor with the
     character to the left.

transpose-words (ESC-T ESC-t) (unbound) (unbound)
     Exchange the current word with the one before it.

     With a positive numeric argument _N_, the word around the cursor,
     or following it if the cursor is between words, is transposed with
     the preceding _N_ words.  The cursor is put at the end of the
     resulting group of words.

     With a negative numeric argument _-N_, the effect is the same as
     using a positive argument _N_ except that the original cursor
     position is retained, regardless of how the words are rearranged.

vi-unindent (unbound) (<) (unbound)
     Unindent a number of lines.

vi-up-case (unbound) (gU) (unbound)
     Read a movement command from the keyboard, and convert all
     characters from the cursor position to the endpoint of the
     movement to lowercase.  If the movement command is vi-up-case,
     swap the case of all characters on the current line.

up-case-word (ESC-U ESC-u) (unbound) (unbound)
     Convert the current word to all caps and move past it.

yank (^Y) (unbound) (unbound)
     Insert the contents of the kill buffer at the cursor position.

yank-pop (ESC-y) (unbound) (unbound)
     Remove the text just yanked, rotate the kill-ring (the history of
     previously killed text) and yank the new top.  Only works following
     yank, vi-put-before, vi-put-after or yank-pop.

vi-yank (unbound) (y) (unbound)
     Read a movement command from the keyboard, and copy the region
     from the cursor position to the endpoint of the movement into the
     kill buffer.  If the command is vi-yank, copy the current line.

vi-yank-whole-line (unbound) (Y) (unbound)
     Copy the current line into the kill buffer.

vi-yank-eol
     Copy the region from the cursor position to the end of the line
     into the kill buffer.  Arguably, this is what Y should do in vi,
     but it isn't what it actually does.



File: zsh.info,  Node: Arguments,  Next: Completion,  Prev: Modifying Text,  Up: Zle Widgets

18.6.4 Arguments
----------------


digit-argument (ESC-0..ESC-9) (1-9) (unbound)
     Start a new numeric argument, or add to the current one.  See also
     vi-digit-or-beginning-of-line.  This only works if bound to a key
     sequence ending in a decimal digit.

     Inside a widget function, a call to this function treats the last
     key of the key sequence which called the widget as the digit.

neg-argument (ESC--) (unbound) (unbound)
     Changes the sign of the following argument.

universal-argument
     Multiply the argument of the next command by 4.  Alternatively, if
     this command is followed by an integer (positive or negative), use
     that as the argument for the next command.  Thus digits cannot be
     repeated using this command.  For example, if this command occurs
     twice, followed immediately by forward-char, move forward sixteen
     spaces; if instead it is followed by -2, then forward-char, move
     backward two spaces.

     Inside a widget function, if passed an argument, i.e. `zle
     universal-argument NUM', the numeric argument will be set to NUM;
     this is equivalent to `NUMERIC=NUM'.

argument-base
     Use the existing numeric argument as a numeric base, which must be
     in the range 2 to 36 inclusive.  Subsequent use of digit-argument
     and universal-argument will input a new numeric argument in the
     given base.  The usual hexadecimal convention is used: the letter
     a or A corresponds to 10, and so on.  Arguments in bases requiring
     digits from 10 upwards are more conveniently input with
     universal-argument, since ESC-a etc. are not usually bound to
     digit-argument.

     The function can be used with a command argument inside a
     user-defined widget.  The following code sets the base to 16 and
     lets the user input a hexadecimal argument until a key out of the
     digit range is typed:


          zle argument-base 16
          zle universal-argument



File: zsh.info,  Node: Completion,  Next: Miscellaneous,  Prev: Arguments,  Up: Zle Widgets

18.6.5 Completion
-----------------


accept-and-menu-complete
     In a menu completion, insert the current completion into the
     buffer, and advance to the next possible completion.

complete-word
     Attempt completion on the current word.

delete-char-or-list (^D) (unbound) (unbound)
     Delete the character under the cursor.  If the cursor is at the
     end of the line, list possible completions for the current word.

expand-cmd-path
     Expand the current command to its full pathname.

expand-or-complete (TAB) (unbound) (TAB)
     Attempt shell expansion on the current word.  If that fails,
     attempt completion.

expand-or-complete-prefix
     Attempt shell expansion on the current word up to cursor.

expand-history (ESC-space ESC-!) (unbound) (unbound)
     Perform history expansion on the edit buffer.

expand-word (^X*) (unbound) (unbound)
     Attempt shell expansion on the current word.

list-choices (ESC-^D) (^D =) (^D)
     List possible completions for the current word.

list-expand (^Xg ^XG) (^G) (^G)
     List the expansion of the current word.

magic-space
     Perform history expansion and insert a space into the buffer.
     This is intended to be bound to space.

menu-complete
     Like complete-word, except that menu completion is used.  See the
     MENU_COMPLETE option.

menu-expand-or-complete
     Like expand-or-complete, except that menu completion is used.

reverse-menu-complete
     Perform menu completion, like menu-complete, except that if a menu
     completion is already in progress, move to the _previous_
     completion rather than the next.

end-of-list
     When a previous completion displayed a list below the prompt, this
     widget can be used to move the prompt below the list.



File: zsh.info,  Node: Miscellaneous,  Next: Text Objects,  Prev: Completion,  Up: Zle Widgets

18.6.6 Miscellaneous
--------------------


accept-and-hold (ESC-A ESC-a) (unbound) (unbound)
     Push the contents of the buffer on the buffer stack and execute it.

accept-and-infer-next-history
     Execute the contents of the buffer.  Then search the history list
     for a line matching the current one and push the event following
     onto the buffer stack.

accept-line (^J ^M) (^J ^M) (^J ^M)
     Finish editing the buffer.  Normally this causes the buffer to be
     executed as a shell command.

accept-line-and-down-history (^O) (unbound) (unbound)
     Execute the current line, and push the next history event on the
     buffer stack.

auto-suffix-remove
     If the previous action added a suffix (space, slash, etc.) to the
     word on the command line, remove it.  Otherwise do nothing.
     Removing the suffix ends any active menu completion or menu
     selection.

     This widget is intended to be called from user-defined widgets to
     enforce a desired suffix-removal behavior.

auto-suffix-retain
     If the previous action added a suffix (space, slash, etc.) to the
     word on the command line, force it to be preserved.  Otherwise do
     nothing.  Retaining the suffix ends any active menu completion or
     menu selection.

     This widget is intended to be called from user-defined widgets to
     enforce a desired suffix-preservation behavior.

beep
     Beep, unless the BEEP option is unset.

bracketed-paste
     This widget is invoked when text is pasted to the terminal
     emulator. It is not intended to be bound to actual keys but
     instead to the special sequence generated by the terminal emulator
     when text is pasted.

     When invoked interactively, the pasted text is inserted to the
     buffer and placed in the cutbuffer.  If a numeric argument is
     given, shell quoting will be applied to the pasted text before it
     is inserted.

     When a named buffer is specified with vi-set-buffer ("x), the
     pasted text is stored in that named buffer but not inserted.

     When called from a widget function as `bracketed-paste NAME`, the
     pasted text is assigned to the variable NAME and no other
     processing is done.

     See also the zle_bracketed_paste parameter.

vi-cmd-mode (^X^V) (unbound) (^[)
     Enter command mode; that is, select the `vicmd' keymap.  Yes, this
     is bound by default in emacs mode.

vi-caps-lock-panic
     Hang until any lowercase key is pressed.  This is for vi users
     without the mental capacity to keep track of their caps lock key
     (like the author).

clear-screen (^L ESC-^L) (^L) (^L)
     Clear the screen and redraw the prompt.

deactivate-region
     Make the current region inactive. This disables vim-style visual
     selection mode if it is active.

describe-key-briefly
     Reads a key sequence, then prints the function bound to that
     sequence.

exchange-point-and-mark (^X^X) (unbound) (unbound)
     Exchange the cursor position (point) with the position of the mark.
     Unless a negative numeric argument is given, the region between
     point and mark is activated so that it can be highlighted.  If a
     zero numeric argument is given, the region is activated but point
     and mark are not swapped.

execute-named-cmd (ESC-x) (:) (unbound)
     Read the name of an editor command and execute it.  Aliasing this
     widget with `zle -A' or replacing it with `zle -N' has no effect
     when interpreting key bindings, but `zle execute-named-cmd' will
     invoke such an alias or replacement.

     A restricted set of editing functions is available in the
     mini-buffer.  Keys are looked up in the special command keymap,
     and if not found there in the main keymap.  An interrupt signal,
     as defined by the stty setting, will abort the function.  Note
     that the following always perform the same task within the
     executed-named-cmd environment and cannot be replaced by user
     defined widgets, nor can the set of functions be extended.  The
     allowed functions are: backward-delete-char,
     vi-backward-delete-char, clear-screen, redisplay, quoted-insert,
     vi-quoted-insert, backward-kill-word, vi-backward-kill-word,
     kill-whole-line, vi-kill-line, backward-kill-line, list-choices,
     delete-char-or-list, complete-word, accept-line,
     expand-or-complete and expand-or-complete-prefix.

     kill-region kills the last word, and vi-cmd-mode is treated the
     same as accept-line.  The space and tab characters, if not bound
     to one of these functions, will complete the name and then list the
     possibilities if the AUTO_LIST option is set.  Any other character
     that is not bound to self-insert or self-insert-unmeta will beep
     and be ignored.  The bindings of the current insert mode will be
     used.

     Currently this command may not be redefined or called by name.

execute-last-named-cmd (ESC-z) (unbound) (unbound)
     Redo the last function executed with execute-named-cmd.

     Like execute-named-cmd, this command may not be redefined, but it
     may be called by name.

get-line (ESC-G ESC-g) (unbound) (unbound)
     Pop the top line off the buffer stack and insert it at the cursor
     position.

pound-insert (unbound) (#) (unbound)
     If there is no # character at the beginning of the buffer, add one
     to the beginning of each line.  If there is one, remove a # from
     each line that has one.  In either case, accept the current line.
     The INTERACTIVE_COMMENTS option must be set for this to have any
     usefulness.

vi-pound-insert
     If there is no # character at the beginning of the current line,
     add one.  If there is one, remove it.  The INTERACTIVE_COMMENTS
     option must be set for this to have any usefulness.

push-input
     Push the entire current multiline construct onto the buffer stack
     and return to the top-level (PS1) prompt.  If the current parser
     construct is only a single line, this is exactly like push-line.
     Next time the editor starts up or is popped with get-line, the
     construct will be popped off the top of the buffer stack and loaded
     into the editing buffer.

push-line (^Q ESC-Q ESC-q) (unbound) (unbound)
     Push the current buffer onto the buffer stack and clear the buffer.
     Next time the editor starts up, the buffer will be popped off the
     top of the buffer stack and loaded into the editing buffer.

push-line-or-edit
     At the top-level (PS1) prompt, equivalent to push-line.  At a
     secondary (PS2) prompt, move the entire current multiline
     construct into the editor buffer.  The latter is equivalent to
     push-input followed by get-line.

read-command
     Only useful from a user-defined widget.  A keystroke is read just
     as in normal operation, but instead of the command being executed
     the name of the command that would be executed is stored in the
     shell parameter REPLY.  This can be used as the argument of a
     future zle command.  If the key sequence is not bound, status 1 is
     returned; typically, however, REPLY is set to undefined-key to
     indicate a useless key sequence.

recursive-edit
     Only useful from a user-defined widget.  At this point in the
     function, the editor regains control until one of the standard
     widgets which would normally cause zle to exit (typically an
     accept-line caused by hitting the return key) is executed.
     Instead, control returns to the user-defined widget.  The status
     returned is non-zero if the return was caused by an error, but the
     function still continues executing and hence may tidy up.  This
     makes it safe for the user-defined widget to alter the command
     line or key bindings temporarily.

     The following widget, caps-lock, serves as an example.


          self-insert-ucase() {
            LBUFFER+=${(U)KEYS[-1]}
          }

          integer stat

          zle -N self-insert self-insert-ucase
          zle -A caps-lock save-caps-lock
          zle -A accept-line caps-lock

          zle recursive-edit
          stat=$?

          zle -A .self-insert self-insert
          zle -A save-caps-lock caps-lock
          zle -D save-caps-lock

          (( stat )) && zle send-break

          return $stat

     This causes typed letters to be inserted capitalised until either
     accept-line (i.e. typically the return key) is typed or the
     caps-lock widget is invoked again; the later is handled by saving
     the old definition of caps-lock as save-caps-lock and then
     rebinding it to invoke accept-line.  Note that an error from the
     recursive edit is detected as a non-zero return status and
     propagated by using the send-break widget.

redisplay (unbound) (^R) (^R)
     Redisplays the edit buffer.

reset-prompt (unbound) (unbound) (unbound)
     Force the prompts on both the left and right of the screen to be
     re-expanded, then redisplay the edit buffer.  This reflects
     changes both to the prompt variables themselves and changes in the
     expansion of the values (for example, changes in time or
     directory, or changes to the value of variables referred to by the
     prompt).

     Otherwise, the prompt is only expanded each time zle starts, and
     when the display has been interrupted by output from another part
     of the shell (such as a job notification) which causes the command
     line to be reprinted.

     reset-prompt doesn't alter the special parameter LASTWIDGET.

     

send-break (^G ESC-^G) (unbound) (unbound)
     Abort the current editor function, e.g. execute-named-command, or
     the editor itself, e.g. if you are in vared. Otherwise abort the
     parsing of the current line; in this case the aborted line is
     available in the shell variable ZLE_LINE_ABORTED.  If the editor
     is aborted from within vared, the variable ZLE_VARED_ABORTED is
     set.

run-help (ESC-H ESC-h) (unbound) (unbound)
     Push the buffer onto the buffer stack, and execute the command
     `run-help CMD', where CMD is the current command.  run-help is
     normally aliased to man.

vi-set-buffer (unbound) (") (unbound)
     Specify a buffer to be used in the following command.  There are
     37 buffers that can be specified: the 26 `named' buffers "a to "z,
     the `yank' buffer "0, the nine `queued' buffers "1 to "9 and the
     `black hole' buffer "_.  The named buffers can also be specified
     as "A to "Z.

     When a buffer is specified for a cut, change or yank command, the
     text concerned replaces the previous contents of the specified
     buffer. If a named buffer is specified using a capital, the newly
     cut text is appended to the buffer instead of overwriting it. When
     using the "_ buffer, nothing happens. This can be useful for
     deleting text without affecting any buffers.

     If no buffer is specified for a cut or change command, "1 is used,
     and the contents of "1 to "8 are each shifted along one buffer;
     the contents of "9 is lost. If no buffer is specified for a yank
     command, "0 is used. Finally, a paste command without a specified
     buffer will paste the text from the most recent command regardless
     of any buffer that might have been used with that command.

     When called from a widget function by the zle command, the buffer
     can optionally be specified with an argument. For example,


          zle vi-set-buffer A

vi-set-mark (unbound) (m) (unbound)
     Set the specified mark at the cursor position.

set-mark-command (^@) (unbound) (unbound)
     Set the mark at the cursor position.  If called with a negative
     numeric argument, do not set the mark but deactivate the region so
     that it is no longer highlighted (it is still usable for other
     purposes).  Otherwise the region is marked as active.

spell-word (ESC-$ ESC-S ESC-s) (unbound) (unbound)
     Attempt spelling correction on the current word.

split-undo
     Breaks the undo sequence at the current change.  This is useful in
     vi mode as changes made in insert mode are coalesced on entering
     command mode.  Similarly, undo will normally revert as one all the
     changes made by a user-defined widget.

undefined-key
     This command is executed when a key sequence that is not bound to
     any command is typed.  By default it beeps.

undo (^_ ^Xu ^X^U) (u) (unbound)
     Incrementally undo the last text modification.  When called from a
     user-defined widget, takes an optional argument indicating a
     previous state of the undo history as returned by the
     UNDO_CHANGE_NO variable; modifications are undone until that state
     is reached, subject to any limit imposed by the UNDO_LIMIT_NO
     variable.

     Note that when invoked from vi command mode, the full prior change
     made in insert mode is reverted, the changes having been merged
     when command mode was selected.

redo (unbound) (^R) (unbound)
     Incrementally redo undone text modifications.

vi-undo-change (unbound) (unbound) (unbound)
     Undo the last text modification.  If repeated, redo the
     modification.

visual-mode (unbound) (v) (unbound)
     Toggle vim-style visual selection mode. If line-wise visual mode is
     currently enabled then it is changed to being character-wise. If
     used following an operator, it forces the subsequent movement
     command to be treated as a character-wise movement.

visual-line-mode (unbound) (V) (unbound)
     Toggle vim-style line-wise visual selection mode. If character-wise
     visual mode is currently enabled then it is changed to being
     line-wise. If used following an operator, it forces the subsequent
     movement command to be treated as a line-wise movement.

what-cursor-position (^X=) (ga) (unbound)
     Print the character under the cursor, its code as an octal,
     decimal and hexadecimal number, the current cursor position within
     the buffer and the column of the cursor in the current line.

where-is
     Read the name of an editor command and print the listing of key
     sequences that invoke the specified command.  A restricted set of
     editing functions is available in the mini-buffer.  Keys are
     looked up in the special command keymap, and if not found there in
     the main keymap.

which-command (ESC-?) (unbound) (unbound)
     Push the buffer onto the buffer stack, and execute the command
     `which-command CMD'. where CMD is the current command.
     which-command is normally aliased to whence.

vi-digit-or-beginning-of-line (unbound) (0) (unbound)
     If the last command executed was a digit as part of an argument,
     continue the argument.  Otherwise, execute vi-beginning-of-line.



File: zsh.info,  Node: Text Objects,  Prev: Miscellaneous,  Up: Zle Widgets

18.6.7 Text Objects
-------------------

Text objects are commands that can be used to select a block of text
according to some criteria. They are a feature of the vim text editor
and so are primarily intended for use with vi operators or from visual
selection mode. However, they can also be used from vi-insert or emacs
mode. Key bindings listed below apply to the viopp and visual keymaps.


select-a-blank-word (aW)
     Select a word including adjacent blanks, where a word is defined
     as a series of non-blank characters. With a numeric argument,
     multiple words will be selected.

select-a-shell-word (aa)
     Select the current command argument applying the normal rules for
     quoting.

select-a-word (aw)
     Select a word including adjacent blanks, using the normal vi-style
     word definition. With a numeric argument, multiple words will be
     selected.

select-in-blank-word (iW)
     Select a word, where a word is defined as a series of non-blank
     characters. With a numeric argument, multiple words will be
     selected.

select-in-shell-word (ia)
     Select the current command argument applying the normal rules for
     quoting. If the argument begins and ends with matching quote
     characters, these are not included in the selection.

select-in-word (iw)
     Select a word, using the normal vi-style word definition. With a
     numeric argument, multiple words will be selected.




File: zsh.info,  Node: Character Highlighting,  Prev: Zle Widgets,  Up: Zsh Line Editor

18.7 Character Highlighting
===========================

The line editor has the ability to highlight characters or regions of
the line that have a particular significance.  This is controlled by
the array parameter zle_highlight, if it has been set by the user.

If the parameter contains the single entry none all highlighting is
turned off.  Note the parameter is still expected to be an array.

Otherwise each entry of the array should consist of a word indicating a
context for highlighting, then a colon, then a comma-separated list of
the types of highlighting to apply in that context.

The contexts available for highlighting are the following:


default
     Any text within the command line not affected by any other
     highlighting.  Text outside the editable area of the command line
     is not affected.

isearch
     When one of the incremental history search widgets is active, the
     area of the command line matched by the search string or pattern.

region
     The currently selected text. In emacs terminology, this is
     referred to as the region and is bounded by the cursor (point) and
     the mark. The region is only highlighted if it is active, which is
     the case after the mark is modified with set-mark-command or
     exchange-point-and-mark.  Note that whether or not the region is
     active has no effect on its use within emacs style widgets, it
     simply determines whether it is highlighted. In vi mode, the
     region corresponds to selected text in visual mode.

special
     Individual characters that have no direct printable representation
     but are shown in a special manner by the line editor.  These
     characters are described below.

suffix
     This context is used in completion for characters that are marked
     as suffixes that will be removed if the completion ends at that
     point, the most obvious example being a slash (/) after a
     directory name.  Note that suffix removal is configurable; the
     circumstances under which the suffix will be removed may differ
     for different completions.

paste
     Following a command to paste text, the characters that were
     inserted.


When region_highlight is set, the contexts that describe a region --
isearch, region, suffix, and paste -- are applied first, then
region_highlight is applied, then the remaining zle_highlight contexts
are applied.  If a particular character is affected by multiple
specifications, the last specification wins.

zle_highlight may contain additional fields for controlling how
terminal sequences to change colours are output.  Each of the following
is followed by a colon and a string in the same form as for key
bindings.  This will not be necessary for the vast majority of
terminals as the defaults shown in parentheses are widely used.


fg_start_code (\e[3)
     The start of the escape sequence for the foreground colour.  This
     is followed by one to three ASCII digits representing the colour.
     Only used for palette colors, i.e. not 24-bit colors specified via
     a color triplet.

fg_default_code (9)
     The number to use instead of the colour to reset the default
     foreground colour.

fg_end_code (m)
     The end of the escape sequence for the foreground colour.

bg_start_code (\e[4)
     The start of the escape sequence for the background colour.  See
     fg_start_code above.

bg_default_code (9)
     The number to use instead of the colour to reset the default
     background colour.

bg_end_code (m)
     The end of the escape sequence for the background colour.


The available types of highlighting are the following.  Note that not
all types of highlighting are available on all terminals:


none
     No highlighting is applied to the given context.  It is not useful
     for this to appear with other types of highlighting; it is used to
     override a default.

fg=COLOUR
     The foreground colour should be set to COLOUR, a decimal integer,
     the name of one of the eight most widely-supported colours or as a
     `#' followed by an RGB triplet in hexadecimal format.

     Not all terminals support this and, of those that do, not all
     provide facilities to test the support, hence the user should
     decide based on the terminal type.  Most terminals support the
     colours black, red, green, yellow, blue, magenta, cyan and white,
     which can be set by name.  In addition. default may be used to set
     the terminal's default foreground colour.  Abbreviations are
     allowed; b or bl selects black.  Some terminals may generate
     additional colours if the bold attribute is also present.

     On recent terminals and on systems with an up-to-date terminal
     database the number of colours supported may be tested by the
     command `echotc Co'; if this succeeds, it indicates a limit on the
     number of colours which will be enforced by the line editor.  The
     number of colours is in any case limited to 256 (i.e. the range 0
     to 255).

     Some modern terminal emulators have support for 24-bit true colour
     (16 million colours). In this case, the hex triplet format can be
     used. This consists of a `#' followed by either a three or six
     digit hexadecimal number describing the red, green and blue
     components of the colour. Hex triplets can also be used with 88
     and 256 colour terminals via the zsh/nearcolor module (see *Note
     The zsh/nearcolor Module::).

     Colour is also known as color.

bg=COLOUR
     The background colour should be set to COLOUR.  This works
     similarly to the foreground colour, except the background is not
     usually affected by the bold attribute.

bold
     The characters in the given context are shown in a bold font.  Not
     all terminals distinguish bold fonts.

standout
     The characters in the given context are shown in the terminal's
     standout mode.  The actual effect is specific to the terminal; on
     many terminals it is inverse video.  On some such terminals, where
     the cursor does not blink it appears with standout mode negated,
     making it less than clear where the cursor actually is.  On such
     terminals one of the other effects may be preferable for
     highlighting the region and matched search string.

underline
     The characters in the given context are shown underlined.  Some
     terminals show the foreground in a different colour instead; in
     this case whitespace will not be highlighted.


The characters described above as `special' are as follows.  The
formatting described here is used irrespective of whether the characters
are highlighted:


ASCII control characters
     Control characters in the ASCII range are shown as `^' followed by
     the base character.

Unprintable multibyte characters
     This item applies to control characters not in the ASCII range,
     plus other characters as follows.  If the MULTIBYTE option is in
     effect, multibyte characters not in the ASCII character set that
     are reported as having zero width are treated as combining
     characters when the option COMBINING_CHARS is on.  If the option
     is off, or if a character appears where a combining character is
     not valid, the character is treated as unprintable.

     Unprintable multibyte characters are shown as a hexadecimal number
     between angle brackets.  The number is the code point of the
     character in the wide character set; this may or may not be
     Unicode, depending on the operating system.

Invalid multibyte characters
     If the MULTIBYTE option is in effect, any sequence of one or more
     bytes that does not form a valid character in the current character
     set is treated as a series of bytes each shown as a special
     character.  This case can be distinguished from other unprintable
     characters as the bytes are represented as two hexadecimal digits
     between angle brackets, as distinct from the four or eight digits
     that are used for unprintable characters that are nonetheless
     valid in the current character set.

     Not all systems support this: for it to work, the system's
     representation of wide characters must be code values from the
     Universal Character Set, as defined by IS0 10646 (also known as
     Unicode).

Wrapped double-width characters
     When a double-width character appears in the final column of a
     line, it is instead shown on the next line. The empty space left
     in the original position is highlighted as a special character.


If zle_highlight is not set or no value applies to a particular
context, the defaults applied are equivalent to


     zle_highlight=(region:standout special:standout
     suffix:bold isearch:underline paste:standout)

i.e. both the region and special characters are shown in standout mode.

Within widgets, arbitrary regions may be highlighted by setting the
special array parameter region_highlight; see *Note Zle Widgets::.




File: zsh.info,  Node: Completion Widgets,  Next: Completion System,  Prev: Zsh Line Editor,  Up: Top

19 Completion Widgets
*********************



19.1 Description
================

The shell's programmable completion mechanism can be manipulated in two
ways; here the low-level features supporting the newer, function-based
mechanism are defined.  A complete set of shell functions based on these
features is described in the next chapter, *Note Completion System::,
and users with no interest in adding to that system (or, potentially,
writing their own -- see dictionary entry for `hubris') should skip the
current section.  The older system based on the compctl builtin command
is described in *Note Completion Using compctl::.

Completion widgets are defined by the -C option to the zle builtin
command provided by the zsh/zle module (see *Note The zsh/zle
Module::). For example,


     zle -C complete expand-or-complete completer

defines a widget named `complete'.  The second argument is the name of
any of the builtin widgets that handle completions: complete-word,
expand-or-complete, expand-or-complete-prefix, menu-complete,
menu-expand-or-complete, reverse-menu-complete, list-choices, or
delete-char-or-list.  Note that this will still work even if the widget
in question has been re-bound.

When this newly defined widget is bound to a key using the bindkey
builtin command defined in the zsh/zle module (*Note Zsh Line
Editor::), typing that key will call the shell function `completer'.
This function is responsible for generating the possible matches using
the builtins described below.  As with other ZLE widgets, the function
is called with its standard input closed.

Once the function returns, the completion code takes over control again
and treats the matches in the same manner as the specified builtin
widget, in this case expand-or-complete.



* Menu:

* Completion Special Parameters::
* Completion Builtin Commands::
* Completion Condition Codes::
* Completion Matching Control::
* Completion Widget Example::



File: zsh.info,  Node: Completion Special Parameters,  Next: Completion Builtin Commands,  Up: Completion Widgets

19.2 Completion Special Parameters
==================================

The parameters ZLE_REMOVE_SUFFIX_CHARS and ZLE_SPACE_SUFFIX_CHARS are
used by the completion mechanism, but are not special. See *Note
Parameters Used By The Shell::.

Inside completion widgets, and any functions called from them, some
parameters have special meaning; outside these functions they are not
special to the shell in any way.  These parameters are used to pass
information between the completion code and the completion widget. Some
of the builtin commands and the condition codes use or change the
current values of these parameters.  Any existing values will be hidden
during execution of completion widgets; except for compstate, the
parameters are reset on each function exit (including nested function
calls from within the completion widget) to the values they had when
the function was entered.


CURRENT
     This is the number of the current word, i.e. the word the cursor is
     currently on in the words array.  Note that this value is only
     correct if the ksharrays option is not set.

IPREFIX
     Initially this will be set to the empty string.  This parameter
     functions like PREFIX; it contains a string which precedes the one
     in PREFIX and is not considered part of the list of matches.
     Typically, a string is transferred from the beginning of PREFIX to
     the end of IPREFIX, for example:


          IPREFIX=${PREFIX%%\=*}=
          PREFIX=${PREFIX#*=}

     causes the part of the prefix up to and including the first equal
     sign not to be treated as part of a matched string.  This can be
     done automatically by the compset builtin, see below.

ISUFFIX
     As IPREFIX, but for a suffix that should not be considered part of
     the matches; note that the ISUFFIX string follows the SUFFIX
     string.

PREFIX
     Initially this will be set to the part of the current word from the
     beginning of the word up to the position of the cursor; it may be
     altered to give a common prefix for all matches.

QIPREFIX
     This parameter is read-only and contains the quoted string up to
     the word being completed. E.g. when completing `"foo', this
     parameter contains the double quote. If the -q option of compset
     is used (see below), and the original string was `"foo bar' with
     the cursor on the `bar', this parameter contains `"foo '.

QISUFFIX
     Like QIPREFIX, but containing the suffix.

SUFFIX
     Initially this will be set to the part of the current word from the
     cursor position to the end; it may be altered to give a common
     suffix for all matches.  It is most useful when the option
     COMPLETE_IN_WORD is set, as otherwise the whole word on the
     command line is treated as a prefix.

compstate
     This is an associative array with various keys and values that the
     completion code uses to exchange information with the completion
     widget.  The keys are:


    all_quotes
          The -q option of the compset builtin command (see below)
          allows a quoted string to be broken into separate words; if
          the cursor is on one of those words, that word will be
          completed, possibly invoking `compset -q' recursively.  With
          this key it is possible to test the types of quoted strings
          which are currently broken into parts in this fashion.  Its
          value contains one character for each quoting level.  The
          characters are a single quote or a double quote for strings
          quoted with these characters, a dollars sign for strings
          quoted with $'...' and a backslash for strings not starting
          with a quote character.  The first character in the value
          always corresponds to the innermost quoting level.

    context
          This will be set by the completion code to the overall context
          in which completion is attempted. Possible values are:


         array_value
               when completing inside the value of an array parameter
               assignment; in this case the words array contains the
               words inside the parentheses.

         brace_parameter
               when completing the name of a parameter in a parameter
               expansion beginning with ${.  This context will also be
               set when completing parameter flags following ${(; the
               full command line argument is presented and the handler
               must test the value to be completed to ascertain that
               this is the case.

         assign_parameter
               when completing the name of a parameter in a parameter
               assignment.

         command
               when completing for a normal command (either in command
               position or for an argument of the command).

         condition
               when completing inside a `[[...]]' conditional
               expression; in this case the words array contains only
               the words inside the conditional expression.

         math
               when completing in a mathematical environment such as a
               `((...))' construct.

         parameter
               when completing the name of a parameter in a parameter
               expansion beginning with $ but not ${.

         redirect
               when completing after a redirection operator.

         subscript
               when completing inside a parameter subscript.

         value
               when completing the value of a parameter assignment.


    exact
          Controls the behaviour when the REC_EXACT option is set.  It
          will be set to accept if an exact match would be accepted,
          and will be unset otherwise.

          If it was set when at least one match equal to the string on
          the line was generated, the match is accepted.

    exact_string
          The string of an exact match if one was found, otherwise
          unset.

    ignored
          The number of words that were ignored because they matched
          one of the patterns given with the -F option to the compadd
          builtin command.

    insert
          This controls the manner in which a match is inserted into
          the command line.  On entry to the widget function, if it is
          unset the command line is not to be changed; if set to
          unambiguous, any prefix common to all matches is to be
          inserted; if set to automenu-unambiguous, the common prefix
          is to be inserted and the next invocation of the completion
          code may start menu completion (due to the AUTO_MENU option
          being set); if set to menu or automenu menu completion will
          be started for the matches currently generated (in the latter
          case this will happen because the AUTO_MENU is set). The
          value may also contain the string `tab' when the completion
          code would normally not really do completion, but only insert
          the TAB character.

          On exit it may be set to any of the values above (where
          setting it to the empty string is the same as unsetting it),
          or to a number, in which case the match whose number is given
          will be inserted into the command line.  Negative numbers
          count backward from the last match (with `-1' selecting the
          last match) and out-of-range values are wrapped around, so
          that a value of zero selects the last match and a value one
          more than the maximum selects the first. Unless the value of
          this key ends in a space, the match is inserted as in a menu
          completion, i.e. without automatically appending a space.

          Both menu and automenu may also specify the number of the
          match to insert, given after a colon.  For example, `menu:2'
          says to start menu completion, beginning with the second
          match.

          Note that a value containing the substring `tab' makes the
          matches generated be ignored and only the TAB be inserted.

          Finally, it may also be set to all, which makes all matches
          generated be inserted into the line.

    insert_positions
          When the completion system inserts an unambiguous string into
          the line, there may be multiple places where characters are
          missing or where the character inserted differs from at least
          one match.  The value of this key contains a colon separated
          list of all these positions, as indexes into the command line.

    last_prompt
          If this is set to a non-empty string for every match added,
          the completion code will move the cursor back to the previous
          prompt after the list of completions has been displayed.
          Initially this is set or unset according to the
          ALWAYS_LAST_PROMPT option.

    list
          This controls whether or how the list of matches will be
          displayed.  If it is unset or empty they will never be
          listed; if its value begins with list, they will always be
          listed; if it begins with autolist or ambiguous, they will be
          listed when the AUTO_LIST or LIST_AMBIGUOUS options
          respectively would normally cause them to be.

          If the substring force appears in the value, this makes the
          list be shown even if there is only one match. Normally, the
          list would be shown only if there are at least two matches.

          The value contains the substring packed if the LIST_PACKED
          option is set. If this substring is given for all matches
          added to a group, this group will show the LIST_PACKED
          behavior. The same is done for the LIST_ROWS_FIRST option
          with the substring rows.

          Finally, if the value contains the string explanations, only
          the explanation strings, if any, will be listed and if it
          contains messages, only the messages (added with the -x
          option of compadd) will be listed.  If it contains both
          explanations and messages both kinds of explanation strings
          will be listed.  It will be set appropriately on entry to a
          completion widget and may be changed there.

    list_lines
          This gives the number of lines that are needed to display the
          full list of completions.  Note that to calculate the total
          number of lines to display you need to add the number of
          lines needed for the command line to this value, this is
          available as the value of the BUFFERLINES special parameter.

    list_max
          Initially this is set to the value of the LISTMAX parameter.
          It may be set to any other value; when the widget exits this
          value will be used in the same way as the value of LISTMAX.

    nmatches
          The number of matches generated and accepted by the
          completion code so far.

    old_insert
          On entry to the widget this will be set to the number of the
          match of an old list of completions that is currently
          inserted into the command line. If no match has been
          inserted, this is unset.

          As with old_list, the value of this key will only be used if
          it is the string keep. If it was set to this value by the
          widget and there was an old match inserted into the command
          line, this match will be kept and if the value of the insert
          key specifies that another match should be inserted, this
          will be inserted after the old one.

    old_list
          This is set to yes if there is still a valid list of
          completions from a previous completion at the time the widget
          is invoked.  This will usually be the case if and only if the
          previous editing operation was a completion widget or one of
          the builtin completion functions.  If there is a valid list
          and it is also currently shown on the screen, the value of
          this key is shown.

          After the widget has exited the value of this key is only
          used if it was set to keep.  In this case the completion code
          will continue to use this old list.  If the widget generated
          new matches, they will not be used.

    parameter
          The name of the parameter when completing in a subscript or
          in the value of a parameter assignment.

    pattern_insert
          Normally this is set to menu, which specifies that menu
          completion will be used whenever a set of matches was
          generated using pattern matching.  If it is set to any other
          non-empty string by the user and menu completion is not
          selected by other option settings, the code will instead
          insert any common prefix for the generated matches as with
          normal completion.

    pattern_match
          Locally controls the behaviour given by the GLOB_COMPLETE
          option.  Initially it is set to `*' if and only if the option
          is set.  The completion widget may set it to this value, to
          an empty string (which has the same effect as unsetting it),
          or to any other non-empty string.  If it is non-empty,
          unquoted metacharacters on the command line will be treated
          as patterns; if it is `*', then additionally a wildcard `*'
          is assumed at the cursor position; if it is empty or unset,
          metacharacters will be treated literally.

          Note that the matcher specifications given to the compadd
          builtin command are not used if this is set to a non-empty
          string.

    quote
          When completing inside quotes, this contains the quotation
          character (i.e. either a single quote, a double quote, or a
          backtick).  Otherwise it is unset.

    quoting
          When completing inside single quotes, this is set to the
          string single; inside double quotes, the string double;
          inside backticks, the string backtick.  Otherwise it is unset.

    redirect
          The redirection operator when completing in a redirection
          position, i.e. one of <, >, etc.

    restore
          This is set to auto before a function is entered, which
          forces the special parameters mentioned above (words,
          CURRENT, PREFIX, IPREFIX, SUFFIX, and ISUFFIX) to be restored
          to their previous values when the function exits.   If a
          function unsets it or sets it to any other string, they will
          not be restored.

    to_end
          Specifies the occasions on which the cursor is moved to the
          end of a string when a match is inserted.  On entry to a
          widget function, it may be single if this will happen when a
          single unambiguous match was inserted or match if it will
          happen any time a match is inserted (for example, by menu
          completion; this is likely to be the effect of the
          ALWAYS_TO_END option).

          On exit, it may be set to single as above.  It may also be
          set to always, or to the empty string or unset; in those
          cases the cursor will be moved to the end of the string
          always or never respectively.  Any other string is treated as
          match.

    unambiguous
          This key is read-only and will always be set to the common
          (unambiguous) prefix the completion code has generated for
          all matches added so far.

    unambiguous_cursor
          This gives the position the cursor would be placed at if the
          common prefix in the unambiguous key were inserted, relative
          to the value of that key. The cursor would be placed before
          the character whose index is given by this key.

    unambiguous_positions
          This contains all positions where characters in the
          unambiguous string are missing or where the character
          inserted differs from at least one of the matches.  The
          positions are given as indexes into the string given by the
          value of the unambiguous key.

    vared
          If completion is called while editing a line using the vared
          builtin, the value of this key is set to the name of the
          parameter given as an argument to vared.  This key is only
          set while a vared command is active.


words
     This array contains the words present on the command line
     currently being edited.




File: zsh.info,  Node: Completion Builtin Commands,  Next: Completion Condition Codes,  Prev: Completion Special Parameters,  Up: Completion Widgets

19.3 Completion Builtin Commands
================================


compadd [ -akqQfenUl12C ] [ -F ARRAY ]
        [-P PREFIX ] [ -S SUFFIX ]
        [-p HIDDEN-PREFIX ] [ -s HIDDEN-SUFFIX ]
        [-i IGNORED-PREFIX ] [ -I IGNORED-SUFFIX ]
        [-W FILE-PREFIX ] [ -d ARRAY ]
        [-J GROUP-NAME ] [ -X EXPLANATION ] [ -x MESSAGE ]
        [-V GROUP-NAME ] [ -o [ ORDER ] ]
        [-r REMOVE-CHARS ] [ -R REMOVE-FUNC ]
        [-D ARRAY ] [ -O ARRAY ] [ -A ARRAY ]
        [-E NUMBER ]
        [-M MATCH-SPEC ] [ -- ] [ WORDS ... ]
     This builtin command can be used to add matches directly and
     control all the information the completion code stores with each
     possible match. The return status is zero if at least one match
     was added and non-zero if no matches were added.

     The completion code breaks the string to complete into seven
     fields in the order:



          <IPRE><APRE><HPRE><WORD><HSUF><ASUF><ISUF>

     The first field is an ignored prefix taken from the command line,
     the contents of the IPREFIX parameter plus the string given with
     the -i option. With the -U option, only the string from the -i
     option is used. The field <APRE> is an optional prefix string
     given with the -P option.  The <HPRE> field is a string that is
     considered part of the match but that should not be shown when
     listing completions, given with the -p option; for example,
     functions that do filename generation might specify a common path
     prefix this way.  <WORD> is the part of the match that should
     appear in the list of completions, i.e. one of the WORDS given at
     the end of the compadd command line. The suffixes <HSUF>, <ASUF>
     and <ISUF> correspond to the prefixes <HPRE>, <APRE> and <IPRE>
     and are given by the options -s, -S and -I, respectively.

     The supported flags are:


    -P PREFIX
          This gives a string to be inserted before the given WORDS.
          The string given is not considered as part of the match and
          any shell metacharacters in it will not be quoted when the
          string is inserted.

    -S SUFFIX
          Like -P, but gives a string to be inserted after the match.

    -p HIDDEN-PREFIX
          This gives a string that should be inserted into the command
          line before the match but that should not appear in the list
          of matches. Unless the -U option is given, this string must
          be matched as part of the string on the command line.

    -s HIDDEN-SUFFIX
          Like `-p', but gives a string to insert after the match.

    -i IGNORED-PREFIX
          This gives a string to insert into the command line just
          before any string given with the `-P' option.  Without `-P'
          the string is inserted before the string given with `-p' or
          directly before the match.

    -I IGNORED-SUFFIX
          Like -i, but gives an ignored suffix.

    -a
          With this flag the WORDS are taken as names of arrays and the
          possible matches are their values.  If only some elements of
          the arrays are needed, the WORDS may also contain subscripts,
          as in `foo[2,-1]'.

    -k
          With this flag the WORDS are taken as names of associative
          arrays and the possible matches are their keys.  As for -a,
          the WORDS may also contain subscripts, as in `foo[(R)*bar*]'.

    -d ARRAY
          This adds per-match display strings. The ARRAY should contain
          one element per WORD given. The completion code will then
          display the first element instead of the first WORD, and so
          on. The ARRAY may be given as the name of an array parameter
          or directly as a space-separated list of words in parentheses.

          If there are fewer display strings than WORDS, the leftover
          WORDS will be displayed unchanged and if there are more
          display strings than WORDS, the leftover display strings will
          be silently ignored.

    -l
          This option only has an effect if used together with the -d
          option. If it is given, the display strings are listed one
          per line, not arrayed in columns.

    -o [ ORDER ]
          This controls the order in which matches are sorted. ORDER is
          a comma-separated list comprising the following possible
          values.  These values can be abbreviated to their initial two
          or three characters.  Note that the order forms part of the
          group name space so matches with different orderings will not
          be in the same group.


         match
               If given, the order of the output is determined by the
               match strings; otherwise it is determined by the display
               strings (i.e. the strings given by the -d option). This
               is the default if `-o' is specified but the ORDER
               argument is omitted.

         nosort
               This specifies that the matches are pre-sorted and their
               order should be preserved.  This value only makes sense
               alone and cannot be combined with any others.

         numeric
               If the matches include numbers, sort them numerically
               rather than lexicographically.

         reverse
               Arrange the matches backwards by reversing the sort
               ordering.


    -J GROUP-NAME
          Gives the name of the group of matches the words should be
          stored in.

    -V GROUP-NAME
          Like -J but naming an unsorted group. This option is
          identical to the combination of -J and -o nosort.

    -1
          If given together with the -V option, makes only consecutive
          duplicates in the group be removed. If combined with the -J
          option, this has no visible effect. Note that groups with and
          without this flag are in different name spaces.

    -2
          If given together with the -J or -V option, makes all
          duplicates be kept. Again, groups with and without this flag
          are in different name spaces.

    -X EXPLANATION
          The EXPLANATION string will be printed with the list of
          matches, above the group currently selected.

          Within the EXPLANATION, the following sequences may be used to
          specify output attributes (see *Note Prompt Expansion::):
          `%B', `%S', `%U', `%F', `%K' and their lower case
          counterparts, as well as `%{...%}'.  `%F', `%K' and `%{...%}'
          take arguments in the same form as prompt expansion.  (Note
          that the sequence `%G' is not available; an argument to `%{'
          should be used instead.)  The sequence `%%' produces a
          literal `%'.

          These sequences are most often employed by users when
          customising the format style (see *Note Completion System::),
          but they must also be taken into account when writing
          completion functions, as passing descriptions with unescaped
          `%' characters to utility functions such as _arguments and
          _message may produce unexpected results. If arbitrary text is
          to be passed in a description, it can be escaped using e.g.
          ${my_str//\%/%%}.

    -x MESSAGE
          Like -X, but the MESSAGE will be printed even if there are no
          matches in the group.

    -q
          The suffix given with -S will be automatically removed if the
          next character typed is a blank or does not insert anything,
          or if the suffix consists of only one character and the next
          character typed is the same character.

    -r REMOVE-CHARS
          This is a more versatile form of the -q option.  The suffix
          given with -S or the slash automatically added after
          completing directories will be automatically removed if the
          next character typed inserts one of the characters given in
          the REMOVE-CHARS.  This string is parsed as a characters
          class and understands the backslash sequences used by the
          print command.  For example, `-r "a-z\t"' removes the suffix
          if the next character typed inserts a lower case character or
          a TAB, and `-r "^0-9"' removes the suffix if the next
          character typed inserts anything but a digit. One extra
          backslash sequence is understood in this string: `\-' stands
          for all characters that insert nothing. Thus `-S "=" -q' is
          the same as `-S "=" -r "= \t\n\-"'.

          This option may also be used without the -S option; then any
          automatically added space will be removed when one of the
          characters in the list is typed.

    -R REMOVE-FUNC
          This is another form of the -r option. When a suffix has been
          inserted and the completion accepted, the function
          REMOVE-FUNC will be called after the next character typed.
          It is passed the length of the suffix as an argument and can
          use the special parameters available in ordinary
          (non-completion) zle widgets (see *Note Zsh Line Editor::) to
          analyse and modify the command line.

    -f
          If this flag is given, all of the matches built from WORDS are
          marked as being the names of files.  They are not required to
          be actual filenames, but if they are, and the option
          LIST_TYPES is set, the characters describing the types of the
          files in the completion lists will be shown. This also forces
          a slash to be added when the name of a directory is completed.

    -e
          This flag can be used to tell the completion code that the
          matches added are parameter names for a parameter expansion.
          This will make the AUTO_PARAM_SLASH and AUTO_PARAM_KEYS
          options be used for the matches.

    -W FILE-PREFIX
          This string is a pathname that will be prepended to each of
          the matches formed by the given WORDS together with any
          prefix specified by the -p option to form a complete filename
          for testing.  Hence it is only useful if combined with the -f
          flag, as the tests will not otherwise be performed.

    -F ARRAY
          Specifies an array containing patterns. Words matching one of
          these patterns are ignored, i.e. not considered to be
          possible matches.

          The ARRAY may be the name of an array parameter or a list of
          literal patterns enclosed in parentheses and quoted, as in
          `-F "(*?.o *?.h)"'. If the name of an array is given, the
          elements of the array are taken as the patterns.

    -Q
          This flag instructs the completion code not to quote any
          metacharacters in the words when inserting them into the
          command line.

    -M MATCH-SPEC
          This gives local match specifications as described below in
          *Note Completion Matching Control::. This option may be given
          more than once.  In this case all MATCH-SPECs given are
          concatenated with spaces between them to form the
          specification string to use.  Note that they will only be
          used if the -U option is not given.

    -n
          Specifies that the words added are to be used as possible
          matches, but are not to appear in the completion listing.

    -U
          If this flag is given, all words given will be accepted and
          no matching will be done by the completion code. Normally
          this is used in functions that do the matching themselves.

    -O ARRAY
          If this option is given, the WORDS are _not_ added to the set
          of possible completions.  Instead, matching is done as usual
          and all of the WORDS given as arguments that match the string
          on the command line will be stored in the array parameter
          whose name is given as ARRAY.

    -A ARRAY
          As the -O option, except that instead of those of the WORDS
          which match being stored in ARRAY, the strings generated
          internally by the completion code are stored. For example,
          with a matching specification of `-M "L:|no="', the string
          `nof' on the command line and the string `foo' as one of the
          WORDS, this option stores the string `nofoo' in the array,
          whereas the -O option stores the `foo' originally given.

    -D ARRAY
          As with -O, the WORDS are not added to the set of possible
          completions.  Instead, the completion code tests whether each
          WORD in turn matches what is on the line.  If the Nth WORD
          does not match, the Nth element of the ARRAY is removed.
          Elements for which the corresponding WORD is matched are
          retained.

    -C
          This option adds a special match which expands to all other
          matches when inserted into the line, even those that are
          added after this option is used.  Together with the -d option
          it is possible to specify a string that should be displayed
          in the list for this special match.  If no string is given,
          it will be shown as a string containing the strings that
          would be inserted for the other matches, truncated to the
          width of the screen.

    -E NUMBER
          This option adds NUMBER empty matches after the WORDS have
          been added.  An empty match takes up space in completion
          listings but will never be inserted in the line and can't be
          selected with menu completion or menu selection.  This makes
          empty matches only useful to format completion lists and to
          make explanatory string be shown in completion lists (since
          empty matches can be given display strings with the -d
          option).  And because all but one empty string would
          otherwise be removed, this option implies the -V and -2
          options (even if an explicit -J option is given).  This can be
          important to note as it affects the name space into which
          matches are added.

    -
    --
          This flag ends the list of flags and options. All arguments
          after it will be taken as the words to use as matches even if
          they begin with hyphens.


     Except for the -M flag, if any of these flags is given more than
     once, the first one (and its argument) will be used.

compset -p NUMBER
compset -P [ NUMBER ] PATTERN
compset -s NUMBER
compset -S [ NUMBER ] PATTERN
compset -n BEGIN [ END ]
compset -N BEG-PAT [ END-PAT ]
compset -q
     This command simplifies modification of the special parameters,
     while its return status allows tests on them to be carried out.

     The options are:


    -p NUMBER
          If the value of the PREFIX parameter is at least NUMBER
          characters long, the first NUMBER characters are removed from
          it and appended to the contents of the IPREFIX parameter.

    -P [ NUMBER ] PATTERN
          If the value of the PREFIX parameter begins with anything that
          matches the PATTERN, the matched portion is removed from
          PREFIX and appended to IPREFIX.

          Without the optional NUMBER, the longest match is taken, but
          if NUMBER is given, anything up to the NUMBERth match is
          moved.  If the NUMBER is negative, the NUMBERth longest match
          is moved. For example, if PREFIX contains the string `a=b=c',
          then compset -P '*\=' will move the string `a=b=' into the
          IPREFIX parameter, but compset -P 1 '*\=' will move only the
          string `a='.

    -s NUMBER
          As -p, but transfer the last NUMBER characters from the value
          of SUFFIX to the front of the value of ISUFFIX.

    -S [ NUMBER ] PATTERN
          As -P, but match the last portion of SUFFIX and transfer the
          matched portion to the front of the value of ISUFFIX.

    -n BEGIN [ END ]
          If the current word position as specified by the parameter
          CURRENT is greater than or equal to BEGIN, anything up to the
          BEGINth word is removed from the words array and the value of
          the parameter CURRENT is decremented by BEGIN.

          If the optional END is given, the modification is done only if
          the current word position is also less than or equal to END.
          In this case, the words from position END onwards are also
          removed from the words array.

          Both BEGIN and END may be negative to count backwards from
          the last element of the words array.

    -N BEG-PAT [ END-PAT ]
          If one of the elements of the words array before the one at
          the index given by the value of the parameter CURRENT matches
          the pattern BEG-PAT, all elements up to and including the
          matching one are removed from the words array and the value
          of CURRENT is changed to point to the same word in the
          changed array.

          If the optional pattern END-PAT is also given, and there is an
          element in the words array matching this pattern, the
          parameters are modified only if the index of this word is
          higher than the one given by the CURRENT parameter (so that
          the matching word has to be after the cursor). In this case,
          the words starting with the one matching end-pat are also
          removed from the words array. If words contains no word
          matching END-PAT, the testing and modification is performed
          as if it were not given.

    -q
          The word currently being completed is split on spaces into
          separate words, respecting the usual shell quoting
          conventions.  The resulting words are stored in the words
          array, and CURRENT, PREFIX, SUFFIX, QIPREFIX, and QISUFFIX
          are modified to reflect the word part that is completed.


     In all the above cases the return status is zero if the test
     succeeded and the parameters were modified and non-zero otherwise.
     This allows one to use this builtin in tests such as:


          if compset -P '*\='; then ...

     This forces anything up to and including the last equal sign to be
     ignored by the completion code.

compcall [ -TD ]
     This allows the use of completions defined with the compctl builtin
     from within completion widgets.  The list of matches will be
     generated as if one of the non-widget completion functions
     (complete-word, etc.)  had been called, except that only compctls
     given for specific commands are used. To force the code to try
     completions defined with the -T option of compctl and/or the
     default completion (whether defined by compctl -D or the builtin
     default) in the appropriate places, the -T and/or -D flags can be
     passed to compcall.

     The return status can be used to test if a matching compctl
     definition was found. It is non-zero if a compctl was found and
     zero otherwise.

     Note that this builtin is defined by the zsh/compctl module.




File: zsh.info,  Node: Completion Condition Codes,  Next: Completion Matching Control,  Prev: Completion Builtin Commands,  Up: Completion Widgets

19.4 Completion Condition Codes
===============================



The following additional condition codes for use within the [[ ... ]]
construct are available in completion widgets.  These work on the
special parameters.  All of these tests can also be performed by the
compset builtin, but in the case of the condition codes the contents of
the special parameters are not modified.


-prefix [ NUMBER ] PATTERN
     true if the test for the -P option of compset would succeed.

-suffix [ NUMBER ] PATTERN
     true if the test for the -S option of compset would succeed.

-after BEG-PAT
     true if the test of the -N option with only the BEG-PAT given
     would succeed.

-between BEG-PAT END-PAT
     true if the test for the -N option with both patterns would
     succeed.




File: zsh.info,  Node: Completion Matching Control,  Next: Completion Widget Example,  Prev: Completion Condition Codes,  Up: Completion Widgets

19.5 Completion Matching Control
================================

It is possible by use of the -M option of the compadd builtin command
to specify how the characters in the string to be completed (referred
to here as the command line) map onto the characters in the list of
matches produced by the completion code (referred to here as the trial
completions). Note that this is not used if the command line contains a
glob pattern and the GLOB_COMPLETE option is set or the pattern_match
of the compstate special association is set to a non-empty string.

The MATCH-SPEC given as the argument to the -M option (see *Note
Completion Builtin Commands::) consists of one or more matching
descriptions separated by whitespace.  Each description consists of a
letter followed by a colon and then the patterns describing which
character sequences on the line match which character sequences in the
trial completion.  Any sequence of characters not handled in this
fashion must match exactly, as usual.

The forms of MATCH-SPEC understood are as follows. In each case, the
form with an upper case initial character retains the string already
typed on the command line as the final result of completion, while with
a lower case initial character the string on the command line is changed
into the corresponding part of the trial completion.


m:LPAT=TPAT
M:LPAT=TPAT
     Here, LPAT is a pattern that matches on the command line,
     corresponding to TPAT which matches in the trial completion.

l:LANCHOR|LPAT=TPAT
L:LANCHOR|LPAT=TPAT
l:LANCHOR||RANCHOR=TPAT
L:LANCHOR||RANCHOR=TPAT
b:LPAT=TPAT
B:LPAT=TPAT
     These letters are for patterns that are anchored by another
     pattern on the left side. Matching for LPAT and TPAT is as for m
     and M, but the pattern LPAT matched on the command line must be
     preceded by the pattern LANCHOR.  The LANCHOR can be blank to
     anchor the match to the start of the command line string;
     otherwise the anchor can occur anywhere, but must match in both
     the command line and trial completion strings.

     If no LPAT is given but a RANCHOR is, this matches the gap between
     substrings matched by LANCHOR and RANCHOR. Unlike LANCHOR, the
     RANCHOR only needs to match the trial completion string.

     The b and B forms are similar to l and L with an empty anchor, but
     need to match only the beginning of the word on the command line
     or trial completion, respectively.

r:LPAT|RANCHOR=TPAT
R:LPAT|RANCHOR=TPAT
r:LANCHOR||RANCHOR=TPAT
R:LANCHOR||RANCHOR=TPAT
e:LPAT=TPAT
E:LPAT=TPAT
     As l, L, b and B, with the difference that the command line and
     trial completion patterns are anchored on the right side.  Here an
     empty RANCHOR and the e and E forms force the match to the end of
     the command line or trial completion string.

x:
     This form is used to mark the end of matching specifications:
     subsequent specifications are ignored. In a single standalone list
     of specifications this has no use but where matching specifications
     are accumulated, such as from nested function calls, it can allow
     one function to override another.


Each LPAT, TPAT or ANCHOR is either an empty string or consists of a
sequence of literal characters (which may be quoted with a backslash),
question marks, character classes, and correspondence classes; ordinary
shell patterns are not used.  Literal characters match only themselves,
question marks match any character, and character classes are formed as
for globbing and match any character in the given set.

Correspondence classes are defined like character classes, but with two
differences: they are delimited by a pair of braces, and negated classes
are not allowed, so the characters ! and ^ have no special meaning
directly after the opening brace.  They indicate that a range of
characters on the line match a range of characters in the trial
completion, but (unlike ordinary character classes) paired according to
the corresponding position in the sequence.  For example, to make any
ASCII lower case letter on the line match the corresponding upper case
letter in the trial completion, you can use `m:{a-z}={A-Z}' (however,
see below for the recommended form for this).  More than one pair of
classes can occur, in which case the first class before the =
corresponds to the first after it, and so on.  If one side has more
such classes than the other side, the superfluous classes behave like
normal character classes.  In anchor patterns correspondence classes
also behave like normal character classes.

The standard `[:NAME:]' forms described for standard shell patterns (see
*Note Filename Generation::) may appear in correspondence classes as
well as normal character classes.  The only special behaviour in
correspondence classes is if the form on the left and the form on the
right are each one of [:upper:], [:lower:].  In these cases the
character in the word and the character on the line must be the same up
to a difference in case.  Hence to make any lower case character on the
line match the corresponding upper case character in the trial
completion you can use `m:{[:lower:]}={[:upper:]}'.  Although the
matching system does not yet handle multibyte characters, this is likely
to be a future extension, at which point this syntax will handle
arbitrary alphabets; hence this form, rather than the use of explicit
ranges, is the recommended form.  In other cases `[:NAME:]' forms are
allowed.  If the two forms on the left and right are the same, the
characters must match exactly.  In remaining cases, the corresponding
tests are applied to both characters, but they are not otherwise
constrained; any matching character in one set goes with any matching
character in the other set:  this is equivalent to the behaviour of
ordinary character classes.

The pattern TPAT may also be one or two stars, `*' or `**'. This means
that the pattern on the command line can match any number of characters
in the trial completion. In this case the pattern must be anchored (on
either side); in the case of a single star, the ANCHOR then determines
how much of the trial completion is to be included -- only the
characters up to the next appearance of the anchor will be matched.
With two stars, substrings matched by the anchor can be matched, too.

Examples:

The keys of the options association defined by the parameter module are
the option names in all-lower-case form, without underscores, and
without the optional no at the beginning even though the builtins
setopt and unsetopt understand option names with upper case letters,
underscores, and the optional no.  The following alters the matching
rules so that the prefix no and any underscore are ignored when trying
to match the trial completions generated and upper case letters on the
line match the corresponding lower case letters in the words:


     compadd -M 'L:|[nN][oO]= M:_= M:{[:upper:]}={[:lower:]}' - \
       ${(k)options}

The first part says that the pattern `[nN][oO]' at the beginning (the
empty anchor before the pipe symbol) of the string on the line matches
the empty string in the list of words generated by completion, so it
will be ignored if present. The second part does the same for an
underscore anywhere in the command line string, and the third part uses
correspondence classes so that any upper case letter on the line
matches the corresponding lower case letter in the word. The use of the
upper case forms of the specification characters (L and M) guarantees
that what has already been typed on the command line (in particular the
prefix no) will not be deleted.

Note that the use of L in the first part means that it matches only
when at the beginning of both the command line string and the trial
completion. I.e., the string `_NO_f' would not be completed to
`_NO_foo', nor would `NONO_f' be completed to `NONO_foo' because of the
leading underscore or the second `NO' on the line which makes the
pattern fail even though they are otherwise ignored. To fix this, one
would use `B:[nN][oO]=' instead of the first part. As described above,
this matches at the beginning of the trial completion, independent of
other characters or substrings at the beginning of the command line
word which are ignored by the same or other MATCH-SPECs.

The second example makes completion case insensitive.  This is just the
same as in the option example, except here we wish to retain the
characters in the list of completions:


     compadd -M 'm:{[:lower:]}={[:upper:]}' ...

This makes lower case letters match their upper case counterparts.  To
make upper case letters match the lower case forms as well:


     compadd -M 'm:{[:lower:][:upper:]}={[:upper:][:lower:]}' ...

A nice example for the use of * patterns is partial word completion.
Sometimes you would like to make strings like `c.s.u' complete to
strings like `comp.source.unix', i.e. the word on the command line
consists of multiple parts, separated by a dot in this example, where
each part should be completed separately -- note, however, that the
case where each part of the word, i.e. `comp', `source' and `unix' in
this example, is to be completed from separate sets of matches is a
different problem to be solved by the implementation of the completion
widget.  The example can be handled by:


     compadd -M 'r:|.=* r:|=*' \
       - comp.sources.unix comp.sources.misc ...

The first specification says that LPAT is the empty string, while
ANCHOR is a dot; TPAT is *, so this can match anything except for the
`.' from the anchor in the trial completion word.  So in `c.s.u', the
matcher sees `c', followed by the empty string, followed by the anchor
`.', and likewise for the second dot, and replaces the empty strings
before the anchors, giving `c[omp].s[ources].u[nix]', where the last
part of the completion is just as normal.

With the pattern shown above, the string `c.u' could not be completed
to `comp.sources.unix' because the single star means that no dot
(matched by the anchor) can be skipped. By using two stars as in
`r:|.=**', however, `c.u' could be completed to `comp.sources.unix'.
This also shows that in some cases, especially if the anchor is a real
pattern, like a character class, the form with two stars may result in
more matches than one would like.

The second specification is needed to make this work when the cursor is
in the middle of the string on the command line and the option
COMPLETE_IN_WORD is set. In this case the completion code would
normally try to match trial completions that end with the string as
typed so far, i.e. it will only insert new characters at the cursor
position rather than at the end.  However in our example we would like
the code to recognise matches which contain extra characters after the
string on the line (the `nix' in the example).  Hence we say that the
empty string at the end of the string on the line matches any characters
at the end of the trial completion.

More generally, the specification


     compadd -M 'r:|[.,_-]=* r:|=*' ...

allows one to complete words with abbreviations before any of the
characters in the square brackets.  For example, to complete
veryverylongfile.c rather than veryverylongheader.h with the above in
effect, you can just type very.c before attempting completion.

The specifications with both a left and a right anchor are useful to
complete partial words whose parts are not separated by some special
character. For example, in some places strings have to be completed
that are formed `LikeThis' (i.e. the separate parts are determined by a
leading upper case letter) or maybe one has to complete strings with
trailing numbers. Here one could use the simple form with only one
anchor as in:


     compadd -M 'r:|[[:upper:]0-9]=* r:|=*' LikeTHIS FooHoo 5foo123 5bar234

But with this, the string `H' would neither complete to `FooHoo' nor to
`LikeTHIS' because in each case there is an upper case letter before
the `H' and that is matched by the anchor. Likewise, a `2' would not be
completed. In both cases this could be changed by using
`r:|[[:upper:]0-9]=**', but then `H' completes to both `LikeTHIS' and
`FooHoo' and a `2' matches the other strings because characters can be
inserted before every upper case letter and digit. To avoid this one
would use:


     compadd -M 'r:[^[:upper:]0-9]||[[:upper:]0-9]=** r:|=*' \
         LikeTHIS FooHoo foo123 bar234

By using these two anchors, a `H' matches only upper case `H's that are
immediately preceded by something matching the left anchor
`[^[:upper:]0-9]'. The effect is, of course, that `H' matches only the
string `FooHoo', a `2' matches only `bar234' and so on.

When using the completion system (see *Note Completion System::), users
can define match specifications that are to be used for specific
contexts by using the matcher and matcher-list styles. The values for
the latter will be used everywhere.




File: zsh.info,  Node: Completion Widget Example,  Prev: Completion Matching Control,  Up: Completion Widgets

19.6 Completion Widget Example
==============================



The first step is to define the widget:


     zle -C complete complete-word complete-files

Then the widget can be bound to a key using the bindkey builtin command:


     bindkey '^X\t' complete

After that the shell function complete-files will be invoked after
typing control-X and TAB. The function should then generate the
matches, e.g.:


     complete-files () { compadd - * }

This function will complete files in the current directory matching the
current word.


File: zsh.info,  Node: Completion System,  Next: Completion Using compctl,  Prev: Completion Widgets,  Up: Top

20 Completion System
********************



20.1 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 the previous chapter, *Note Completion Widgets::.

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 in *Note
Initialization::.

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

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


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

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

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

Styles modify various operations of the completion system, such as
output formatting, but also what kinds of completers are used (and in
what order), or which tags are examined.  Styles may accept arguments
and are manipulated using the zstyle command described in *Note The
zsh/zutil Module::.

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

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

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

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



* Menu:

* Initialization::
* Completion System Configuration::
* Control Functions::
* Bindable Commands::
* Completion Functions::
* Completion Directories::
* Completion System Variables::



File: zsh.info,  Node: Initialization,  Next: Completion System Configuration,  Up: Completion System

20.2 Initialization
===================



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

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

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

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



20.2.1 Use of compinit
----------------------



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

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

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

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

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

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

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

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

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

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



20.2.2 Autoloaded files
-----------------------



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

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

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

The tags are:


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

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

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

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

#compdef -k STYLE KEY-SEQUENCE ...
     This option creates a widget behaving like the builtin widget
     STYLE and binds it to the given KEY-SEQUENCEs, if any.  The STYLE
     must be one of the builtin widgets that perform completion, namely
     complete-word, delete-char-or-list, expand-or-complete,
     expand-or-complete-prefix, list-choices, menu-complete,
     menu-expand-or-complete, or reverse-menu-complete.  If the
     zsh/complist module is loaded (see *Note The zsh/complist
     Module::) the widget menu-select is also available.

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

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


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

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

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


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

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


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

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

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

-command-
     A word in command position

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

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

-equal-
     A word beginning with an equals sign

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

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

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

-redirect-
     The word after a redirection operator.

-subscript-
     The contents of a parameter subscript.

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

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


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

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

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

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

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

As an example:


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

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

Also:


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

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

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


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

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



20.2.3 Functions
----------------

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


compdef [ -ane ] FUNCTION NAME ... [ -{p|P} PATTERN ... [ -N NAME ...]]
compdef -d NAME ...
compdef -k [ -an ] FUNCTION STYLE KEY-SEQUENCE [ KEY-SEQUENCE ... ]
compdef -K [ -an ] FUNCTION NAME STYLE KEY-SEQ [ NAME STYLE SEQ ... ]
     The first form defines the FUNCTION to call for completion in the
     given contexts as described for the #compdef tag above.

     Alternatively, all the arguments may have the form `CMD=SERVICE'.
     Here SERVICE should already have been defined by `CMD1=SERVICE'
     lines in #compdef files, as described above.  The argument for CMD
     will be completed in the same way as SERVICE.

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


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

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

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

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

     The parameter $_compskip may be set by any function defined for a
     pattern context.  If it is set to a value containing the substring
     `patterns' none of the pattern-functions will be called; if it is
     set to a value containing the substring `all', no other function
     will be called.  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-SEQUENCEs; this
     is like the #compdef -k tag.  The function should generate the
     completions needed and will otherwise behave like the builtin
     widget whose name is given as the STYLE argument.  The widgets
     usable for this are: complete-word, delete-char-or-list,
     expand-or-complete, expand-or-complete-prefix, list-choices,
     menu-complete, menu-expand-or-complete, and reverse-menu-complete,
     as well as menu-select if the zsh/complist module is loaded.  The
     option -n prevents the key being bound if it is already to bound
     to something other than undefined-key.

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

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


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


     compdef _pids foo

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

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




File: zsh.info,  Node: Completion System Configuration,  Next: Control Functions,  Prev: Initialization,  Up: Completion System

20.3 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.



20.3.1 Overview
---------------

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

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

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

The next few paragraphs explain how a context is composed within the
completion function suite.  Following that is discussion of how _styles_
are defined.  Styles determine such things as how the matches are
generated, similarly to shell options but with much more control.  They
are defined with the zstyle builtin command (*Note The zsh/zutil
Module::).

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


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

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

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

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

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

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


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


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

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


     dvips -o ...

and the completion function will generate filenames.

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

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

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

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


     zstyle ':completion:*' verbose yes

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

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

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


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

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


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

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


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

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

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

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

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



20.3.2 Standard Tags
--------------------



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


accounts
     used to look up the users-hosts style

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

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

arguments
     for arguments to a command

arrays
     for names of array parameters

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

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

builtins
     for names of builtin commands

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

colormapids
     for X colormap ids

colors
     for color names

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

contexts
     for contexts in arguments to the zstyle builtin command

corrections
     used by the _approximate and _correct completers for possible
     corrections

cursors
     for cursor names used by X programs

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

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

devices
     for names of device special files

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

directory-stack
     for entries in the directory stack

displays
     for X display names

domains
     for network domains

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

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

extensions
     for X server extensions

file-descriptors
     for numbers of open file descriptors

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

fonts
     for X font names

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

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

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

groups
     for names of user groups

history-words
     for words from the history

hosts
     for hostnames

indexes
     for array indexes

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

interfaces
     for network interfaces

keymaps
     for names of zsh keymaps

keysyms
     for names of X keysyms

libraries
     for names of system libraries

limits
     for system limits

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

manuals
     for names of manual pages

mailboxes
     for e-mail folders

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

messages
     used to look up the format style for messages

modifiers
     for names of X modifiers

modules
     for modules (e.g. zsh modules)

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

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

names
     for all kinds of names

newsgroups
     for USENET groups

nicknames
     for nicknames of NIS maps

options
     for command options

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

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

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

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

parameters
     for names of parameters

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

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

pods
     for perl pods (documentation files)

ports
     for communication ports

prefixes
     for prefixes (like those of a URL)

printers
     for print queue names

processes
     for process identifiers

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

sequences
     for sequences (e.g. mh sequences)

sessions
     for sessions in the zftp function suite

signals
     for signal names

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

styles
     for styles used by the zstyle builtin command

suffixes
     for filename extensions

tags
     for tags (e.g. rpm tags)

targets
     for makefile targets

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

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

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

users
     for usernames

values
     for one of a set of values in certain lists

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

visuals
     for X visuals

warnings
     used to look up the format style for warnings

widgets
     for zsh widget names

windows
     for IDs of X windows

zsh-options
     for shell options



20.3.3 Standard Styles
----------------------



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

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


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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

completer
     The strings given as the value of this style provide the names of
     the completer functions to use. The available completer functions
     are described in *Note Control Functions::.

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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


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

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

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

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

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

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


          zmodload -i zsh/stat
          disable stat

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

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


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

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


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

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

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

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

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

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

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

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


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

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


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

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

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

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

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

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

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

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

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

     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 *Note The zsh/zutil
     Module::.

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

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

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


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

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

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


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

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

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

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


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

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

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

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

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

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

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

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

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

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


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

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


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


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

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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

list-colors
     If the zsh/complist module is loaded, this style can be used to set
     color specifications.  This mechanism replaces the use of the
     ZLS_COLORS and ZLS_COLOURS parameters described in *Note The
     zsh/complist Module::, but the syntax is the same.

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

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

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


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

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

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

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

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

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

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

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

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

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

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

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

     For example:


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

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

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

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

matcher
     This style is tested separately for each tag valid in the current
     context.  Its value is placed before any match specifications
     given by the matcher-list style so can override them via the use
     of an x: specification.  The value should be in the form described
     in *Note Completion Matching Control::.  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 description of the tag-order style.

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


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

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


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

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


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

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


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

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

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

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

     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 numeric', no correcting
     completion will be attempted unless a numeric argument is given.

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

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

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

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

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

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

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

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

     Similarly, with any of the `false' values (as in `no=10'), menu
     completion will _not_ be used if there are NUM or more matches.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


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

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

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

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

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

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

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

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

     The default value for this style is `false'.

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

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

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

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

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

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

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

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

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

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

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

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

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

     For example,


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

     If the current directory is /home/pws/zsh/Src, then zle_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 decide if all duplicate matches should be
     removed, rather than just consecutive duplicates.

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

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

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

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

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

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

sort
     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.  However, by default the file
     completion function behaves as if there were a `*' between the
     slashes.

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

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

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

     The default for this style is `false'.

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

     The default is `true'.

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

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

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

     For example:


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

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

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


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

    ! TAGS...
          A string starting with an exclamation mark specifies names of
          tags that are _not_ to be used.  The effect is the same as if
          all other possible tags for the context had been listed.

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

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

    TAG:LABEL:DESCRIPTION
          As before, but description will replace the `%d' in the value
          of the format style instead of the default description
          supplied by the completion function.  Spaces in the
          description must be quoted with a backslash.  A `%d' appearing
          in DESCRIPTION is replaced with the description given by the
          completion function.


     In any of the forms above the tag may be a pattern or several
     patterns in the form `{PAT1,PAT2...}'.  In this case all matching
     tags will be used except for any given explicitly in the same
     string.

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


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

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

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


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

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

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


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

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

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


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

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

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

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

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

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

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

     For example,


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

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

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

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

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

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

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

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

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

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

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

users-hosts-ports
     Like users-hosts but used for commands like telnet and containing
     strings of the form `USER@HOST:PORT'.

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

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




File: zsh.info,  Node: Control Functions,  Next: Bindable Commands,  Prev: Completion System Configuration,  Up: Completion System

20.4 Control Functions
======================



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


     zstyle ':completion:*' completer _complete _correct

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

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

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


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

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


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

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


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

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

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


          zstyle ':completion:*' completer _complete _approximate

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

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

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

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

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


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

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

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

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

     See _description for a description of TAG and DESCR.

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

     This function takes no arguments.

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

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

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

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

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

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

     For example, with:


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

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

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

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

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

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

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

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

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

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

     This function is also a bindable command, see *Note Bindable
     Commands::.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

     For example, consider this global completer style:


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

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

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


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

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

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

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

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


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

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





File: zsh.info,  Node: Bindable Commands,  Next: Completion Functions,  Prev: Control Functions,  Up: Completion System

20.5 Bindable Commands
======================



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


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


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

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

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

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

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

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

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

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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

     For example, after executing the following:


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

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

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