Windows PowerShell command on Get-command zshcompwid

Manual Pages for UNIX Operating System command usage for man zshcompwid

User Commands ZSHCOMPWID(1)

NAME

zshcompwid - zsh completion widgets

DESCRIPTION

The shell's programmable completion mechanism can be manipu-

lated 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 dic-

tionary 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 comple-

tions: 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 zsh 4.3.10 Last change: June 1, 2009 1 User Commands ZSHCOMPWID(1) 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 func-

tion 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 con-

sidered 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 pre-

fix for all matches. QIPREFIX

This parameter is read-only and contains the quoted

string up to the word being completed. E.g. when com-

pleting `"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. zsh 4.3.10 Last change: June 1, 2009 2 User Commands ZSHCOMPWID(1) 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 infor-

mation 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 char-

acter 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 ${.

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 zsh 4.3.10 Last change: June 1, 2009 3 User Commands ZSHCOMPWID(1) command). condition

when completing inside a `[[...]]' condi-

tional expression; in this case the words

array contains only the words inside the con-

ditional 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 other-

wise. 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

zsh 4.3.10 Last change: June 1, 2009 4 User Commands ZSHCOMPWID(1)

to be inserted and the next invocation of the com-

pletion 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 max-

imum 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 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 charac-

ter 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 com-

mand 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.

zsh 4.3.10 Last change: June 1, 2009 5 User Commands ZSHCOMPWID(1) 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 sub-

string rows.

Finally, if the value contains the string explana-

tions, 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. zsh 4.3.10 Last change: June 1, 2009 6 User Commands ZSHCOMPWID(1) 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 assign-

ment.

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, zsh 4.3.10 Last change: June 1, 2009 7 User Commands ZSHCOMPWID(1) 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 back-

tick. 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 unam-

biguous 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 respec-

tively. 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. zsh 4.3.10 Last change: June 1, 2009 8 User Commands ZSHCOMPWID(1)

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 unambi-

guous 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 [ -akqQfenUld12C ] [ -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: 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

zsh 4.3.10 Last change: June 1, 2009 9 User Commands ZSHCOMPWID(1)

option, only the string from the -i option is used. The

field is an optional prefix string given with

the -P option. The 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 genera-

tion might specify a common path prefix this way. 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 , and correspond to the prefixes , and 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 zsh 4.3.10 Last change: June 1, 2009 10 User Commands ZSHCOMPWID(1)

`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 ele-

ment instead of the first word, and so on. The

array may be given as the name of an array parame-

ter 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 a 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

zsh 4.3.10 Last change: June 1, 2009 11 User Commands ZSHCOMPWID(1) 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 con-

sists 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 automati-

cally 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 charac-

ters 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 charac-

ter typed inserts anything but a digit. One extra backslash sequence is understood in this string:

`\-' stands for all characters that insert noth-

ing. 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 suf-

fix 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 zsh 4.3.10 Last change: June 1, 2009 12 User Commands ZSHCOMPWID(1) 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 per-

formed.

-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 insert-

ing them into the command line.

-M match-spec

This gives local match specifications as described

below in the section `Completion Matching Con-

trol'. This option may be given more than once.

In this case all match-specs given are con-

catenated 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 com-

pletion code. Normally this is used in functions that do the matching themselves. zsh 4.3.10 Last change: June 1, 2009 13 User Commands ZSHCOMPWID(1)

-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 n'th word does not match,

the n'th element of the array is removed. Ele-

ments 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 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).

zsh 4.3.10 Last change: June 1, 2009 14 User Commands ZSHCOMPWID(1)

-- 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 charac-

ters are removed from it and appended to the con-

tents 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

number'th match is moved. If the number is nega-

tive, the number'th 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. zsh 4.3.10 Last change: June 1, 2009 15 User Commands ZSHCOMPWID(1)

-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 begin'th word is removed

from the words array and the value of the parame-

ter 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 back-

wards 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 match-

ing 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 test-

ing 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, PRE-

FIX, 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 ...

zsh 4.3.10 Last change: June 1, 2009 16 User Commands ZSHCOMPWID(1) 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 function (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 comp-

call. 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 buil-

tin 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 zsh 4.3.10 Last change: June 1, 2009 17 User Commands ZSHCOMPWID(1) 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 com-

pletion. 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 char-

acter 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 lan-

chor. 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 trial completion or the word on the command line, respectively. zsh 4.3.10 Last change: June 1, 2009 18 User Commands ZSHCOMPWID(1) 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 trial comple-

tion or command line string.

Each lpat, tpat or anchor is either an empty string or con-

sists 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 charac-

ters ! 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 comple-

tion, but (unlike ordinary character classes) paired accord-

ing 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 com-

pletion, 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 char-

acter 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 zsh 4.3.10 Last change: June 1, 2009 19 User Commands ZSHCOMPWID(1) 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 con-

strained; 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 char-

acters 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 try-

ing 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'

zsh 4.3.10 Last change: June 1, 2009 20 User Commands ZSHCOMPWID(1)

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 coun-

terparts. 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 zsh 4.3.10 Last change: June 1, 2009 21 User Commands ZSHCOMPWID(1) 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 com-

pletions that end with the string as typed so far, i.e. it will only insert new characters at the cursor position rather then at the end. However in our example we would

like the code to recognise matches which contain extra char-

acters after the string on the line (the `nix' in the exam-

ple). 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 `Lik-

eThis' (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 zsh 4.3.10 Last change: June 1, 2009 22 User Commands ZSHCOMPWID(1)

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.

ATTRIBUTES

See attributes(5) for descriptions of the following attri-

butes:

_______________________________________

| ATTRIBUTE TYPE | ATTRIBUTE VALUE|

|____________________|__________________|_

| Availability | shell/zsh |

|____________________|__________________|_

| Interface Stability| External |

|____________________|_________________|

NOTES Source for zsh is available on http://opensolaris.org. zsh 4.3.10 Last change: June 1, 2009 23