Provided by: zsh-common_5.5.1-1ubuntu2_all bug

NAME

       zshcompwid - zsh completion widgets

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 zshcompsys(1), 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 zshcompctl(1).

       Completion widgets are defined by the -C option to the zle builtin command provided by the
       zsh/zle module (see zshzle(1)). 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 (see zshzle(1)), 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.

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  Parameters  Used  By  The  Shell  in
       zshparam(1).

       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.

COMPLETION BUILTIN COMMANDS

       compadd [ -akqQfenUlo12C ] [ -F array ]
               [-P prefix ] [ -S suffix ]
               [-p hidden-prefix ] [ -s hidden-suffix ]
               [-i ignored-prefix ] [ -I ignored-suffix ]
               [-W file-prefix ] [ -d array ]
               [-J name ] [ -V name ] [ -X explanation ] [ -x message ]
               [-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     This option only has an effect if used together with the -d option.   If  it
                     is  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).

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

              -V name
                     Like  -J  but  naming an unsorted group. These are in a different name space
                     than groups created with the -J flag.

              -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.

              -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 zshzle(1)) 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 the section
                     `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 contents of the PREFIX parameter is longer  than  number  characters,
                     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.

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.

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 `Completion Builtin Commands'
       above) 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 the section
       FILENAME GENERATION in zshexpn(1)) 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  zshcompsys(1)),   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.

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.