readline: Completion Variables
2.6.3 Completion Variables
--------------------------
-- Variable: rl_compentry_func_t * rl_completion_entry_function
A pointer to the generator function for 'rl_completion_matches()'.
'NULL' means to use 'rl_filename_completion_function()', the
default filename completer.
-- Variable: rl_completion_func_t * rl_attempted_completion_function
A pointer to an alternative function to create matches. The
function is called with TEXT, START, and END. START and END are
indices in 'rl_line_buffer' defining the boundaries of TEXT, which
is a character string. If this function exists and returns 'NULL',
or if this variable is set to 'NULL', then 'rl_complete()' will
call the value of 'rl_completion_entry_function' to generate
matches, otherwise the array of strings returned will be used. If
this function sets the 'rl_attempted_completion_over' variable to a
non-zero value, Readline will not perform its default completion
even if this function returns no matches.
-- Variable: rl_quote_func_t * rl_filename_quoting_function
A pointer to a function that will quote a filename in an
application-specific fashion. This is called if filename
completion is being attempted and one of the characters in
'rl_filename_quote_characters' appears in a completed filename.
The function is called with TEXT, MATCH_TYPE, and QUOTE_POINTER.
The TEXT is the filename to be quoted. The MATCH_TYPE is either
'SINGLE_MATCH', if there is only one completion match, or
'MULT_MATCH'. Some functions use this to decide whether or not to
insert a closing quote character. The QUOTE_POINTER is a pointer
to any opening quote character the user typed. Some functions
choose to reset this character.
-- Variable: rl_dequote_func_t * rl_filename_dequoting_function
A pointer to a function that will remove application-specific
quoting characters from a filename before completion is attempted,
so those characters do not interfere with matching the text against
names in the filesystem. It is called with TEXT, the text of the
word to be dequoted, and QUOTE_CHAR, which is the quoting character
that delimits the filename (usually ''' or '"'). If QUOTE_CHAR is
zero, the filename was not in an embedded string.
-- Variable: rl_linebuf_func_t * rl_char_is_quoted_p
A pointer to a function to call that determines whether or not a
specific character in the line buffer is quoted, according to
whatever quoting mechanism the program calling Readline uses. The
function is called with two arguments: TEXT, the text of the line,
and INDEX, the index of the character in the line. It is used to
decide whether a character found in
'rl_completer_word_break_characters' should be used to break words
for the completer.
-- Variable: rl_compignore_func_t * rl_ignore_some_completions_function
This function, if defined, is called by the completer when real
filename completion is done, after all the matching names have been
generated. It is passed a 'NULL' terminated array of matches. The
first element ('matches[0]') is the maximal substring common to all
matches. This function can re-arrange the list of matches as
required, but each element deleted from the array must be freed.
-- Variable: rl_icppfunc_t * rl_directory_completion_hook
This function, if defined, is allowed to modify the directory
portion of filenames Readline completes. It could be used to
expand symbolic links or shell variables in pathnames. It is
called with the address of a string (the current directory name) as
an argument, and may modify that string. If the string is replaced
with a new string, the old value should be freed. Any modified
directory name should have a trailing slash. The modified value
will be used as part of the completion, replacing the directory
portion of the pathname the user typed. At the least, even if no
other expansion is performed, this function should remove any quote
characters from the directory name, because its result will be
passed directly to 'opendir()'.
The directory completion hook returns an integer that should be
non-zero if the function modifies its directory argument. The
function should not modify the directory argument if it returns 0.
-- Variable: rl_icppfunc_t * rl_directory_rewrite_hook;
If non-zero, this is the address of a function to call when
completing a directory name. This function takes the address of
the directory name to be modified as an argument. Unlike
'rl_directory_completion_hook', it only modifies the directory name
used in 'opendir', not what is displayed when the possible
completions are printed or inserted. It is called before
rl_directory_completion_hook. At the least, even if no other
expansion is performed, this function should remove any quote
characters from the directory name, because its result will be
passed directly to 'opendir()'.
The directory rewrite hook returns an integer that should be
non-zero if the function modfies its directory argument. The
function should not modify the directory argument if it returns 0.
-- Variable: rl_icppfunc_t * rl_filename_stat_hook
If non-zero, this is the address of a function for the completer to
call before deciding which character to append to a completed name.
This function modifies its filename name argument, and the modified
value is passed to 'stat()' to determine the file's type and
characteristics. This function does not need to remove quote
characters from the filename.
The stat hook returns an integer that should be non-zero if the
function modfies its directory argument. The function should not
modify the directory argument if it returns 0.
-- Variable: rl_dequote_func_t * rl_filename_rewrite_hook
If non-zero, this is the address of a function called when reading
directory entries from the filesystem for completion and comparing
them to the partial word to be completed. The function should
perform any necessary application or system-specific conversion on
the filename, such as converting between character sets or
converting from a filesystem format to a character input format.
The function takes two arguments: FNAME, the filename to be
converted, and FNLEN, its length in bytes. It must either return
its first argument (if no conversion takes place) or the converted
filename in newly-allocated memory. The converted form is used to
compare against the word to be completed, and, if it matches, is
added to the list of matches. Readline will free the allocated
string.
-- Variable: rl_compdisp_func_t * rl_completion_display_matches_hook
If non-zero, then this is the address of a function to call when
completing a word would normally display the list of possible
matches. This function is called in lieu of Readline displaying
the list. It takes three arguments: ('char **'MATCHES, 'int'
NUM_MATCHES, 'int' MAX_LENGTH) where MATCHES is the array of
matching strings, NUM_MATCHES is the number of strings in that
array, and MAX_LENGTH is the length of the longest string in that
array. Readline provides a convenience function,
'rl_display_match_list', that takes care of doing the display to
Readline's output stream. You may call that function from this
hook.
-- Variable: const char * rl_basic_word_break_characters
The basic list of characters that signal a break between words for
the completer routine. The default value of this variable is the
characters which break words for completion in Bash: '"
\t\n\"\\'`@$><=;|&{("'.
-- Variable: const char * rl_basic_quote_characters
A list of quote characters which can cause a word break.
-- Variable: const char * rl_completer_word_break_characters
The list of characters that signal a break between words for
'rl_complete_internal()'. The default list is the value of
'rl_basic_word_break_characters'.
-- Variable: rl_cpvfunc_t * rl_completion_word_break_hook
If non-zero, this is the address of a function to call when
Readline is deciding where to separate words for word completion.
It should return a character string like
'rl_completer_word_break_characters' to be used to perform the
current completion. The function may choose to set
'rl_completer_word_break_characters' itself. If the function
returns 'NULL', 'rl_completer_word_break_characters' is used.
-- Variable: const char * rl_completer_quote_characters
A list of characters which can be used to quote a substring of the
line. Completion occurs on the entire substring, and within the
substring 'rl_completer_word_break_characters' are treated as any
other character, unless they also appear within this list.
-- Variable: const char * rl_filename_quote_characters
A list of characters that cause a filename to be quoted by the
completer when they appear in a completed filename. The default is
the null string.
-- Variable: const char * rl_special_prefixes
The list of characters that are word break characters, but should
be left in TEXT when it is passed to the completion function.
Programs can use this to help determine what kind of completing to
do. For instance, Bash sets this variable to "$@" so that it can
complete shell variables and hostnames.
-- Variable: int rl_completion_query_items
Up to this many items will be displayed in response to a
possible-completions call. After that, readline asks the user if
she is sure she wants to see them all. The default value is 100.
A negative value indicates that Readline should never ask the user.
-- Variable: int rl_completion_append_character
When a single completion alternative matches at the end of the
command line, this character is appended to the inserted completion
text. The default is a space character (' '). Setting this to the
null character ('\0') prevents anything being appended
automatically. This can be changed in application-specific
completion functions to provide the "most sensible word separator
character" according to an application-specific command line syntax
specification.
-- Variable: int rl_completion_suppress_append
If non-zero, RL_COMPLETION_APPEND_CHARACTER is not appended to
matches at the end of the command line, as described above. It is
set to 0 before any application-specific completion function is
called, and may only be changed within such a function.
-- Variable: int rl_completion_quote_character
When Readline is completing quoted text, as delimited by one of the
characters in RL_COMPLETER_QUOTE_CHARACTERS, it sets this variable
to the quoting character found. This is set before any
application-specific completion function is called.
-- Variable: int rl_completion_suppress_quote
If non-zero, Readline does not append a matching quote character
when performing completion on a quoted string. It is set to 0
before any application-specific completion function is called, and
may only be changed within such a function.
-- Variable: int rl_completion_found_quote
When Readline is completing quoted text, it sets this variable to a
non-zero value if the word being completed contains or is delimited
by any quoting characters, including backslashes. This is set
before any application-specific completion function is called.
-- Variable: int rl_completion_mark_symlink_dirs
If non-zero, a slash will be appended to completed filenames that
are symbolic links to directory names, subject to the value of the
user-settable MARK-DIRECTORIES variable. This variable exists so
that application-specific completion functions can override the
user's global preference (set via the MARK-SYMLINKED-DIRECTORIES
Readline variable) if appropriate. This variable is set to the
user's preference before any application-specific completion
function is called, so unless that function modifies the value, the
user's preferences are honored.
-- Variable: int rl_ignore_completion_duplicates
If non-zero, then duplicates in the matches are removed. The
default is 1.
-- Variable: int rl_filename_completion_desired
Non-zero means that the results of the matches are to be treated as
filenames. This is _always_ zero when completion is attempted, and
can only be changed within an application-specific completion
function. If it is set to a non-zero value by such a function,
directory names have a slash appended and Readline attempts to
quote completed filenames if they contain any characters in
'rl_filename_quote_characters' and 'rl_filename_quoting_desired' is
set to a non-zero value.
-- Variable: int rl_filename_quoting_desired
Non-zero means that the results of the matches are to be quoted
using double quotes (or an application-specific quoting mechanism)
if the completed filename contains any characters in
'rl_filename_quote_chars'. This is _always_ non-zero when
completion is attempted, and can only be changed within an
application-specific completion function. The quoting is effected
via a call to the function pointed to by
'rl_filename_quoting_function'.
-- Variable: int rl_attempted_completion_over
If an application-specific completion function assigned to
'rl_attempted_completion_function' sets this variable to a non-zero
value, Readline will not perform its default filename completion
even if the application's completion function returns no matches.
It should be set only by an application's completion function.
-- Variable: int rl_sort_completion_matches
If an application sets this variable to 0, Readline will not sort
the list of completions (which implies that it cannot remove any
duplicate completions). The default value is 1, which means that
Readline will sort the completions and, depending on the value of
'rl_ignore_completion_duplicates', will attempt to remove duplicate
matches.
-- Variable: int rl_completion_type
Set to a character describing the type of completion Readline is
currently attempting; see the description of
'rl_complete_internal()' (
Completion Functions) for the
list of characters. This is set to the appropriate value before
any application-specific completion function is called, allowing
such functions to present the same interface as 'rl_complete()'.
-- Variable: int rl_completion_invoking_key
Set to the final character in the key sequence that invoked one of
the completion functions that call 'rl_complete_internal()'. This
is set to the appropriate value before any application-specific
completion function is called.
-- Variable: int rl_inhibit_completion
If this variable is non-zero, completion is inhibited. The
completion character will be inserted as any other bound to
'self-insert'.
Info Catalog
readline: Completion Functions
readline: Custom Completers
readline: A Short Completion Example