Provided by: zsh-common_5.9-6ubuntu2_all 
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 completion 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 completions 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 added 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_match (see
below). 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 match 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 [ -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 ] [ -- ] [ completions ... ]
This builtin command can be used to add matches directly and control all the
information the completion code stores with each possible completion. The return
status is zero if at least one match was added and non-zero if no matches were
added.
The completion code breaks each match into seven fields in the order:
<ipre><apre><hpre><body><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. <body> is the part of the match that should appear in
the list of matches shown to the user. 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 each match. 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 each match.
-p hidden-prefix
This gives a string that should be inserted before each 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 each match.
-i ignored-prefix
This gives a string to insert just before any string given with the `-P'
option. Without `-P' the string is inserted before the string given with
`-p' or directly before each match.
-I ignored-suffix
Like -i, but gives an ignored suffix.
-a With this flag the completions are taken as names of arrays and the actual
completions are their values. If only some elements of the arrays are
needed, the completions may also contain subscripts, as in `foo[2,-1]'.
-k With this flag the completions are taken as names of associative arrays and
the actual completions are their keys. As for -a, the words may also
contain subscripts, as in `foo[(R)*bar*]'.
-d array
This adds per-completion display strings. The array should contain one
element per completion given. The completion code will then display the
first element instead of the first completion, 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 completions, the leftover
completions will be displayed unchanged and if there are more display
strings than completions, 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 completions 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 that the matches 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 as described in the section EXPANSION OF PROMPT SEQUENCES
in zshmisc(1): `%B', `%S', `%U', `%F', `%K' and their lower case
counterparts, as well as `%{...%}'. `%F', `%K' and `%{...%}' take arguments
in the same form as prompt expansion. (Note that the sequence `%G' is not
available; an argument to `%{' should be used instead.) The sequence `%%'
produces a literal `%'.
These sequences are most often employed by users when customising the format
style (see zshcompsys(1)), 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 match has been accepted and a
suffix has been inserted, 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 the completions 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 match 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. completions that match one of these
patterns are ignored, that is, not considered to be 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 matches 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 matching completions are to be added to the set of matches,
but are not to be listed to the user.
-U If this flag is given, all completions are added to the set of matches 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 completions are not added to the set of
matches. Instead, matching is done as usual and all of the completions that
match 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 completions which
match being stored in array, the strings generated internally by the
completion code are stored. For example, with a match specification of `-M
"L:|no="', a current word of `nof' and completions of `foo', this option
stores the string `nofoo' in the array, whereas the -O option stores the
`foo' originally given.
-D array
As with -O, the completions are not added to the set of matches. Instead,
whenever the nth completion does not match, the nth element of the array is
removed. Elements for which the corresponding completion matches are
retained. This option can be used more than once to remove elements from
multiple arrays.
-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 matching completions 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 completions 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.
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
When the user invokes completion, the current word on the command line (that is, the word
the cursor is currently on) is used to generate a match pattern. Only those completions
that match the pattern are offered to the user as matches.
The default match pattern is generated from the current word by either
• appending a `*' (matching any number of characters in a completion) or,
• if the shell option COMPLETE_IN_WORD is set, inserting a `*' at the cursor
position.
This narrow pattern can be broadened selectively by passing a match specification to the
compadd builtin command through its -M option (see `Completion Builtin Commands' above).
A match specification consists of one or more matchers separated by whitespace. Matchers
in a match specification are applied one at a time, from left to right. Once all matchers
have been applied, completions are compared to the final match pattern and non-matching
ones are discarded.
• Note that the -M option is ignored if the current word contains a glob pattern and
the shell option GLOB_COMPLETE is set or if the pattern_match key of the special
associative array compstate is set to a non-empty value (see `Completion Special
Parameters' above).
• Users of the completion system (see zshcompsys(1)) should generally not use the -M
option directly, but rather use the matcher-list and matcher styles (see the
subsection Standard Styles in the documentation for COMPLETION SYSTEM CONFIGURATION
in zshcompsys(1)).
Each matcher consists of
• a case-sensitive letter
• a `:',
• one or more patterns separated by pipes (`|'),
• an equals sign (`='), and
• another pattern.
The patterns before the `=' are used to match substrings of the current word. For each
matched substring, the corresponding part of the match pattern is broadened with the
pattern after the `=', by means of a logical OR.
Each pattern in a matcher cosists of either
• the empty string or
• a sequence of
• literal characters (which may be quoted with a `\'),
• question marks (`?'),
• bracket expressions (`[...]'; see the subsection Glob Operators in the
documentation for GLOB OPERATORS in zshexpn(1)), and/or
• brace expressions (see below).
Other shell patterns are not allowed.
A brace expression, like a bracket expression, consists of a list of
• literal characters,
• ranges (`0-9'), and/or
• character classes (`[:name:]').
However, they differ from each other as follows:
• A brace expression is delimited by a pair of braces (`{...}').
• Brace expressions do not support negations. That is, an initial `!' or `^' has no
special meaning and will be interpreted as a literal character.
• When a character in the current word matches the nth pattern in a brace expression,
the corresponding part of the match pattern is broadened only with the nth pattern
of the brace expression on the other side of the `=', if there is one; if there is
no brace expression on the other side, then this pattern is the empty string.
However, if either brace expression has more elements than the other, then the
excess entries are simply ignored. When comparing indexes, each literal character
or character class counts as one element, but each range is instead expanded to the
full list of literal characters it represents. Additionally, if on both sides of
the `=', the nth pattern is `[:upper:]' or `[:lower:]', then these are expanded as
ranges, too.
Note that, although the matching system does not yet handle multibyte characters, this is
likely to be a future extension. Hence, using `[:upper:]' and `[:lower:]' is recommended
over `A-Z' and `a-z'.
Below are the different forms of matchers supported. Each uppercase form behaves exactly
like its lowercase counterpart, but adds an additional step after the match pattern has
filtered out non-matching completions: Each of a match's substrings that was matched by a
subpattern from an uppercase matcher is replaced with the corresponding substring of the
current word. However, patterns from lowercase matchers have higher weight: If a
substring of the current word was matched by patterns from both a lowercase and an
uppercase matcher, then the lowercase matcher's pattern wins and the corresponding part of
the match is not modified.
Unless indicated otherwise, each example listed assumes COMPLETE_IN_WORD to be unset (as
it is by default).
m:word-pat=match-pat
M:word-pat=match-pat
For each substring of the current word that matches word-pat, broaden the
corresponding part of the match pattern to additionally match match-pat.
Examples:
m:{[:lower:]}={[:upper:]} lets any lower case character in the current word
be completed to itself or its uppercase counterpart. So, the completions
`foo', `FOO' and `Foo' will are be considered matches for the word `fo'.
M:_= inserts every underscore from the current word into each match, in the
same relative position, determined by matching the substrings around it.
So, given a completion `foo', the word `f_o' will be completed to the match
`f_oo', even though the latter was not present as a completion.
b:word-pat=match-pat
B:word-pat=match-pat
e:word-pat=match-pat
E:word-pat=match-pat
For each consecutive substring at the b:eginning or e:nd of the current word that
matches word-pat, broaden the corresponding part of the match pattern to
additionally match match-pat.
Examples:
`b:-=+' lets any number of minuses at the start of the current word be
completed to a minus or a plus.
`B:0=' adds all zeroes at the beginning of the current word to the beginning
of each match.
l:|word-pat=match-pat
L:|word-pat=match-pat
R:word-pat|=match-pat
r:word-pat|=match-pat
If there is a substring at the l:eft or r:ight edge of the current word that
matches word-pat, then broaden the corresponding part of the match pattern to
additionally match match-pat.
For each l:, L:, r: and R: matcher (including the ones below), the pattern
match-pat may also be a `*'. This matches any number of characters in a
completion.
Examples:
`r:|=*' appends a `*' to the match pattern, even when COMPLETE_IN_WORD is
set and the cursor is not at the end of the current word.
If the current word starts with a minus, then `L:|-=' will prepend it to
each match.
l:anchor|word-pat=match-pat
L:anchor|word-pat=match-pat
r:word-pat|anchor=match-pat
R:word-pat|anchor=match-pat
For each substring of the current word that matches word-pat and has on its l:eft
or r:ight another substring matching anchor, broaden the corresponding part of the
match pattern to additionally match match-pat.
Note that these matchers (and the ones below) modify only what is matched by
word-pat; they do not change the matching behavior of what is matched by anchor (or
coanchor; see the matchers below). Thus, unless its corresponding part of the
match pattern has been modified, the anchor in the current word has to match
literally in each completion, just like any other substring of the current word.
If a matcher includes at least one anchor (which includes the matchers with two
anchors, below), then match-pat may also be `*' or `**'. `*' can match any part of
a completion that does not contain any substrings matching anchor, whereas a `**'
can match any part of a completion, period. (Note that this is different from the
behavior of `*' in the anchorless forms of `l:' and `r:' and and also different
from `*' and `**' in glob expressions.)
Examples:
`r:|.=*' makes the completion `comp.sources.unix' a match for the word `..u'
-- but not for the word `.u'.
Given a completion `--foo', the matcher `L:--|no-=' will complete the word
`--no-' to the match `--no-foo'.
l:anchor||coanchor=match-pat
L:anchor||coanchor=match-pat
r:coanchor||anchor=match-pat
R:coanchor||anchor=match-pat
For any two consecutive substrings of the current word that match anchor and
coanchor, in the order given, insert the pattern match-pat between their
corresponding parts in the match pattern.
Note that, unlike anchor, the pattern coanchor does not change what `*' can match.
Examples:
`r:?||[[:upper:]]=*' will complete the current word `fB' to `fooBar', but it
will not complete it to `fooHooBar' (because `*' here cannot match anything
that includes a match for `[[:upper:]]), nor will it complete `B' to
`fooBar' (because there is no character in the current word to match
coanchor).
Given the current word `pass.n' and a completion `pass.byname', the matcher
`L:.||[[:alpha:]]=by' will produce the match `pass.name'.
x:
Ignore this matcher and all matchers to its right.
This matcher is used to mark the end of a match specification. In a single
standalone list of matchers, this has no use, but where match specifications are
concatenated, as is often the case when using the completion system (see
zshcompsys(1)), it can allow one match specification to override another.
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.