NAME

Term::ReadLine::Gnu - Perl extension for the GNU Readline/History Library

SYNOPSIS

use Term::ReadLine;   # Do not "use Term::ReadLine::Gnu;"
$term = new Term::ReadLine 'ProgramName';
while ( defined ($_ = $term->readline('prompt>')) ) {
  ...
}

DESCRIPTION

Overview

This is an implementation of Term::ReadLine using the GNU Readline/History Library.

For basic functions object oriented interface is provided. These are described in the section "Standard Methods" and "Term::ReadLine::Gnu Functions".

This package also has the interface with the almost all functions and variables which are documented in the GNU Readline/History Library Manual. They are documented in the section "Term::ReadLine::Gnu Functions" and "Term::ReadLine::Gnu Variables" briefly. For further details of the GNU Readline/History Library, see GNU Readline Library Manual and GNU History Library Manual.

There are some Term::ReadLine::Gnu original features. They are described in the section "Term::ReadLine::Gnu Specific Features"

The sample programs under eg/ directory and test programs under t/ directory in the Term::ReadLine::Gnu distribution include many examples of this module.

Standard Methods

These are standard methods defined by Term::ReadLine.

ReadLine

returns the actual package that executes the commands. If this package is being used, Term::ReadLine::Gnu is returned.

new(NAME,[IN,OUT])

returns the handle for subsequent calls to following functions. Argument is the name of the application. Optionally can be followed by two arguments for IN and OUT file handles. These arguments should be globs.

readline(PROMPT[,PREPUT])

gets an input line, with actual GNU Readline support. Trailing newline is removed. Returns undef on EOF. PREPUT is an optional argument meaning the initial value of input.

The optional argument PREPUT is granted only if the value preput is in Features.

PROMPT may include some escape sequences. Use RL_PROMPT_START_IGNORE to begin a sequence of non-printing characters, and RL_PROMPT_END_IGNORE to end the sequence.

AddHistory(LINE1, LINE2, ...)

adds the lines to the history of input, from where it can be used if the actual readline is present.

IN, OUT

return the file handles for input and output or undef if readline input and output cannot be used for Perl.

MinLine([MAX])

If argument MAX is specified, it is an advice on minimal size of line to be included into history. undef means do not include anything into history. Returns the old value.

findConsole

returns an array with two strings that give most appropriate names for files for input and output using conventions "<$in", ">$out".

Attribs

returns a reference to a hash which describes internal configuration (variables) of the package. Names of keys in this hash conform to standard conventions with the leading rl_ stripped.

See section "Term::ReadLine::Gnu Variables" for supported variables.

Features

Returns a reference to a hash with keys being features present in current implementation. Several optional features are used in the minimal interface: appname should be present if the first argument to new is recognized, and minline should be present if MinLine method is not dummy. autohistory should be present if lines are put into history automatically (maybe subject to MinLine), and addHistory if AddHistory method is not dummy. preput means the second argument to readline method is processed. getHistory and setHistory denote that the corresponding methods are present. tkRunning denotes that a Tk application may run while ReadLine is getting input.

tkRunning

makes Tk event loop run when waiting for user input (i.e., during readline method).

event_loop

See the description of event_loop on Term::ReadLine.

ornaments

makes the command line stand out by using termcap data. The argument to ornaments should be 0, 1, or a string of a form "aa,bb,cc,dd". Four components of this string should be names of terminal capacities, first two will be issued to make the prompt standout, last two to make the input line standout.

newTTY

takes two arguments which are input filehandle and output filehandle. Switches to use these filehandles.

enableUTF8

Enables UTF-8 support.

If STDIN is in UTF-8 by the -C command-line switch or PERL_UNICODE environment variable, or IN file handle has utf8 IO layer, then UTF-8 support is also enabled. In other cases you need this enableUTF8 method.

This is an original method of Term::ReadLine:Gnu.

Term::ReadLine::Gnu Functions

All these GNU Readline/History Library functions supported are callable via method interface and have names which conform to standard conventions with the leading rl_ stripped. For example rl_foo() function is called as $term->foo().

The titles of the following sections are same as the titles of the corresponding sections in the "Programming with GNU Readline" section in the GNU Readline Library Manual. Refer them for further details.

Although it is preferred to use method interface, most methods have lower level functions in Term::ReadLine::Gnu::XS package. To use them a full qualified name is required.

Basic Behavior

The function readline() prints a prompt and then reads and returns a single line of text from the user.

$_ = $term->readline('Enter a line: ');

You can change key-bindings using bind_key(KEY, FUNCTION [,MAP]) function. The first argument, KEY, is the character that you want bind. The second argument, FUNCTION, is the function to call when KEY is pressed. The FUNCTION can be a reference to a Perl function (see "Custom Functions") or a "named function" named by add_defun() function or commands described in the "Bindable Readline Commands" section in the GNU Readline Library Manual.

$term->bind_key(ord "\ci, 'tab-insert');

The above example binds Control-I to the 'tab-insert' command.

Custom Functions

You can write new functions using Perl. The calling sequence for a command foo looks like

sub foo ($count, $key) { ... }

where $count is the numeric argument (or 1 if defaulted) and $key is the key that invoked this function.

Here is an example;

sub reverse_line {              # reverse a whole line
    my($count, $key) = @_;      # ignored in this sample function

    $t->modifying(0, $a->{end}); # save undo information
    $a->{line_buffer} = reverse $a->{line_buffer};
}

See the "Writing a New Function" section in the GNU Readline Library Manual for further details.

Readline Convenience Functions

Naming a Function

add_defun(NAME, FUNCTION [,KEY=-1])

Add name to a Perl function FUNCTION. If optional argument KEY is specified, bind it to the FUNCTION. Returns reference to FunctionPtr.

Example:
      # name `reverse-line' to a function reverse_line(),
      # and bind it to "\C-t"
      $term->add_defun('reverse-line', \&reverse_line, ord "\ct");

Selecting a Keymap

make_bare_keymap

Keymap  rl_make_bare_keymap()

copy_keymap(MAP)

Keymap  rl_copy_keymap(Keymap|str map)

make_keymap

Keymap  rl_make_keymap()

discard_keymap(MAP)

Keymap  rl_discard_keymap(Keymap|str map)

free_keymap(MAP)

void    rl_free_keymap(Keymap|str map)

empty_keymap(MAP)

int     rl_empty_keymap(Keymap|str map)                 # GRL 8.0

get_keymap

Keymap  rl_get_keymap()

set_keymap(MAP)

Keymap  rl_set_keymap(Keymap|str map)

get_keymap_by_name(NAME)

Keymap  rl_get_keymap_by_name(str name)

get_keymap_name(MAP)

str     rl_get_keymap_name(Keymap map)

set_keymap_name(NAME, MAP)

int     rl_set_keymap_name(str name, Keymap|str map)    # GRL 8.0

Binding Keys

bind_key(KEY, FUNCTION [,MAP])

int     rl_bind_key(int key, FunctionPtr|str function,
                    Keymap|str map = rl_get_keymap())

Bind KEY to the FUNCTION. FUNCTION is the name added by the add_defun method. If optional argument MAP is specified, binds in MAP. Returns non-zero in case of error.

bind_key_if_unbound(KEY, FUNCTION [,MAP])

int     rl_bind_key_if_unbound(int key, FunctionPtr|str function,
                               Keymap|str map = rl_get_keymap()) # GRL 5.0

unbind_key(KEY [,MAP])

int     rl_unbind_key(int key, Keymap|str map = rl_get_keymap())

Bind KEY to the null function. Returns non-zero in case of error.

unbind_function(FUNCTION [,MAP])

int     rl_unbind_function(FunctionPtr|str function,
                           Keymap|str map = rl_get_keymap())

unbind_command(COMMAND [,MAP])

int     rl_unbind_command(str command,
                          Keymap|str map = rl_get_keymap())

bind_keyseq(KEYSEQ, FUNCTION [,MAP])

int     rl_bind_keyseq(str keyseq, FunctionPtr|str function,
                       Keymap|str map = rl_get_keymap()) # GRL 5.0

set_key(KEYSEQ, FUNCTION [,MAP])

int     rl_set_key(str keyseq, FunctionPtr|str function,
                   Keymap|str map = rl_get_keymap())    # GRL 4.2

bind_keyseq_if_unbound(KEYSEQ, FUNCTION [,MAP])

int     rl_bind_keyseq_if_unbound(str keyseq, FunctionPtr|str function,
                                  Keymap|str map = rl_get_keymap()) # GRL 5.0

generic_bind(TYPE, KEYSEQ, DATA, [,MAP])

int     rl_generic_bind(int type, str keyseq,
                        FunctionPtr|Keymap|str data,
                        Keymap|str map = rl_get_keymap())

parse_and_bind(LINE)

void    rl_parse_and_bind(str line)

Parse LINE as if it had been read from the ~/.inputrc file and perform any key bindings and variable assignments found. For further detail see GNU Readline Library Manual.

read_init_file([FILENAME])

int     rl_read_init_file(str filename = '~/.inputrc')

Associating Function Names and Bindings

named_function(NAME)

FunctionPtr rl_named_function(str name)

get_function_name(FUNCTION)

str     rl_get_function_name(FunctionPtr function)      # TRG original

function_of_keyseq(KEYSEQ [,MAP])

(FunctionPtr|Keymap|str data, int type)
        rl_function_of_keyseq(str keyseq,
                              Keymap|str map = rl_get_keymap())

trim_arg_from_keyseq(KEYSEQ [,MAP])

int     rl_trim_arg_from_keyseq(str keyseq,
                                Keymap|str map = rl_get_keymap()) # GRL 8.2

invoking_keyseqs(FUNCTION [,MAP])

(@str)  rl_invoking_keyseqs(FunctionPtr|str function,
                            Keymap|str map = rl_get_keymap())

function_dumper([READABLE])

void    rl_function_dumper(int readable = 0)

list_funmap_names

void    rl_list_funmap_names()

funmap_names

(@str)  rl_funmap_names()

add_funmap_entry(NAME, FUNCTION)

int     rl_add_funmap_entry(char *name, FunctionPtr|str function)

Allowing Undoing

begin_undo_group

int     rl_begin_undo_group()

end_undo_group

int     rl_end_undo_group()

add_undo(WHAT, START, END, TEXT)

int     rl_add_undo(int what, int start, int end, str text)

free_undo_list

void    rl_free_undo_list()

do_undo

int     rl_do_undo()

modifying([START [,END]])

int     rl_modifying(int start = 0, int end = rl_end)

Redisplay

redisplay

void    rl_redisplay()

forced_update_display

int     rl_forced_update_display()

on_new_line

int     rl_on_new_line()

on_new_line_with_prompt

int     rl_on_new_line_with_prompt()                    # GRL 4.1

clear_visible_line()

int     rl_clear_visible_line()                         # GRL 7.0

reset_line_state

int     rl_reset_line_state()

crlf

int     rl_crlf()

show_char(C)

int     rl_show_char(int c)

message(FMT[, ...])

int     rl_message(str fmt, ...)

clear_message

int     rl_clear_message()

save_prompt

void    rl_save_prompt()

restore_prompt

void    rl_restore_prompt()

expand_prompt(PROMPT)

int     rl_expand_prompt(str prompt)

set_prompt(PROMPT)

int     rl_set_prompt(const str prompt)                 # GRL 4.2

Modifying Text

insert_text(TEXT)

int     rl_insert_text(str text)

delete_text([START [,END]])

int     rl_delete_text(int start = 0, int end = rl_end)

copy_text([START [,END]])

str     rl_copy_text(int start = 0, int end = rl_end)

kill_text([START [,END]])

int     rl_kill_text(int start = 0, int end = rl_end)

push_macro_input(MACRO)

int     rl_push_macro_input(str macro)

Character Input

read_key

int     rl_read_key()

getc(STREAM)

int     rl_getc(FILE *STREAM)

stuff_char(C)

int     rl_stuff_char(int c)

execute_next(C)

int     rl_execute_next(int c)

clear_pending_input()

int     rl_clear_pending_input()                        # GRL 4.2

set_keyboard_input_timeout(uSEC)

int     rl_set_keyboard_input_timeout(int usec)         # GRL 4.2

set_timeout(SECS, USECS)

int     rl_set_timeout(int secs, int usecs)             # GRL 8.2

clear_timeout()

int     rl_clear_timeout()                              # GRL 8.2

timeout_remaining()

int     rl_timeout_remaining()          # scalar context, GRL 8.2
(int ret, int secs, int usecs)  rl_timeout_remaining()  # array context

Terminal Management

prep_terminal(META_FLAG)

void    rl_prep_terminal(int META_FLAG)

deprep_terminal()

void    rl_deprep_terminal()

tty_set_default_bindings([MAP])

void    rl_tty_set_default_bindings([Keymap|str map = rl_get_keymap()]) # GRL 4.0

tty_unset_default_bindings([MAP])

void    rl_tty_unset_default_bindings([Keymap|str map = rl_get_keymap()]) # GRL 5.0

tty_set_echoing(VALUE)

int     rl_tty_set_echoing(int value)                   # GRL 7.0

reset_terminal([TERMINAL_NAME])

int     rl_reset_terminal(str terminal_name = getenv($TERM))

Utility Functions

save_state(READLINE_STATE)

READLINE_STATE  rl_save_state()                         # GRL 6.0

restore_state(READLINE_STATE)

int     rl_restore_state(READLINE_STATE)                # GRL 6.0

free(MEM)

Not implemented since not required for Perl.
int     rl_free(void *mem)                              # GRL 6.0

replace_line(TEXT [,CLEAR_UNDO])

int     rl_replace_line(str text, int clear_undo = 0)   # GRL 4.3

extend_line_buffer(LEN)

Not implemented since not required for Perl.
int     rl_extend_line_buffer(int len)

initialize

int     rl_initialize()

ding

int     rl_ding()

alphabetic(C)

int     rl_alphabetic(int C)                            # GRL 4.2

display_match_list(MATCHES [,LEN [,MAX]])

void    rl_display_match_list(\@matches, len = $#maches, max) # GRL 4.0

Since the first element of an array @matches as treated as a possible completion, it is not displayed. See the descriptions of completion_matches(). When MAX is omitted, the max length of an item in @matches is used.

Miscellaneous Functions

macro_bind(KEYSEQ, MACRO [,MAP])

int     rl_macro_bind(const str keyseq, const str macro, Keymap map)

macro_dumper(READABLE)

int     rl_macro_dumper(int readline)

variable_bind(VARIABLE, VALUE)

int     rl_variable_bind(const str variable, const str value)

variable_value(VARIABLE)

str     rl_variable_value(const str variable)           # GRL 5.1

variable_dumper(READABLE)

int     rl_variable_dumper(int readline)

set_paren_blink_timeout(uSEC)

int     rl_set_paren_blink_timeout(usec)                # GRL 4.2

get_termcap(cap)

str     rl_get_termcap(cap)

clear_history

void    rl_clear_history()                              # GRL 6.3

activate_mark

void    rl_activate_mark()                              # GRL 8.1

deactivate_mark

void    rl_deactivate_mark()                            # GRL 8.1

keep_mark_active

void    rl_keep_mark_active()                           # GRL 8.1

mark_active_p

int     rl_mark_active_p()                              # GRL 8.1

Alternate Interface

callback_handler_install(PROMPT, LHANDLER)

void    rl_callback_handler_install(str prompt, pfunc lhandler)

callback_read_char

void    rl_callback_read_char()

callback_sigcleanup # GRL 7.0

void    rl_callback_sigcleanup()

callback_handler_remove

void    rl_callback_handler_remove()

Readline Signal Handling

pending_signal()

int     rl_pending_signal()                             # GRL 7.0

cleanup_after_signal

void    rl_cleanup_after_signal()                       # GRL 4.0

free_line_state

void    rl_free_line_state()                            # GRL 4.0

reset_after_signal

void    rl_reset_after_signal()                         # GRL 4.0

check_signals

void    rl_check_signals()                              # GRL 8.0

echo_signal_char

void    rl_echo_signal_char(int sig)                    # GRL 6.0

resize_terminal

void    rl_resize_terminal()                            # GRL 4.0

set_screen_size(ROWS, COLS)

void    rl_set_screen_size(int ROWS, int COLS)          # GRL 4.2

get_screen_size()

(int rows, int cols)    rl_get_screen_size()            # GRL 4.2

reset_screen_size()

void    rl_reset_screen_size()                          # GRL 5.1

set_signals

int     rl_set_signals()                                # GRL 4.0

clear_signals

int     rl_clear_signals()                              # GRL 4.0

Completion Functions

complete_internal([WHAT_TO_DO])

int     rl_complete_internal(int what_to_do = TAB)

completion_mode(FUNCTION)

int     rl_completion_mode(FunctionPtr|str function)    # GRL 4.3

completion_matches(TEXT [,FUNC])

(@str)  rl_completion_matches(str text,
                              pfunc func = filename_completion_function)

filename_completion_function(TEXT, STATE)

str     rl_filename_completion_function(str text, int state)

username_completion_function(TEXT, STATE)

str     rl_username_completion_function(str text, int state)

list_completion_function(TEXT, STATE)

str     list_completion_function(str text, int state)   # TRG original

History Functions

Initializing History and State Management

using_history

void    using_history()

history_get_history_state

HISTORY_STATE   history_get_hitory_state()              # GRL 6.3

history_set_history_state

void    history_set_hitory_state(HISTORY_STATE)         # GRL 6.3

History List Management

add_history(STRING)

void    add_history(str string)

add_history_time(STRING)

void    add_history_time(str string)                    # GRL 5.0

remove_history(WHICH)

str     remove_history(int which)

free_history(HISTENT)

Not implemented since Term::ReadLine::Gnu does not support the
member 'data' of HIST_ENTRY structure. remove_history() frees
the memory.
histdata_t      free_history_entry(HIST_ENTRY *histent) # GRL 5.0

replace_history_entry(WHICH, STRING)

str     replace_history_entry(int which, str string)

clear_history

void    clear_history()

StifleHistory(MAX)

int     stifle_history(int max|undef)

stifles the history list, remembering only the last MAX entries. If MAX is undef, remembers all entries. This is a replacement of unstifle_history().

unstifle_history

int     unstifle_history()

This is equivalent with stifle_history(undef).

history_is_stifled

int     history_is_stifled()

SetHistory(LINE1 [, LINE2, ...])

sets the history of input, from where it can be used if the actual readline is present.

Information About the History List

history_list

Not implemented since not required for Perl.
HIST_ENTRY **history_list()

where_history

int     where_history()

current_history

str     current_history()

history_get(OFFSET)

str     history_get(offset)

history_get_time(OFFSET)

time_t  history_get_time(offset)                        # GRL 5.0

history_total_bytes

int     history_total_bytes()

GetHistory

returns the history of input as a list, if actual readline is present.

Moving Around the History List

history_set_pos(POS)

int     history_set_pos(int pos)

previous_history

str     previous_history()

next_history

str     next_history()

Searching the History List

history_search(STRING [,DIRECTION])

int     history_search(str string, int direction = -1)

history_search_prefix(STRING [,DIRECTION])

int     history_search_prefix(str string, int direction = -1)

history_search_pos(STRING [,DIRECTION [,POS]])

int     history_search_pos(str string,
                           int direction = -1,
                           int pos = where_history())

Managing the History File

ReadHistory([FILENAME [,FROM [,TO]]])

int     read_history(str filename = '~/.history',
                     int from = 0, int to = -1)

int     read_history_range(str filename = '~/.history',
                           int from = 0, int to = -1)

adds the contents of FILENAME to the history list, a line at a time. If FILENAME is false, then read from ~/.history. Start reading at line FROM and end at TO. If FROM is omitted or zero, start at the beginning. If TO is omitted or less than FROM, then read until the end of the file. Returns true if successful, or false if not. read_history() is an alias of read_history_range().

WriteHistory([FILENAME])

int     write_history(str filename = '~/.history')

writes the current history to FILENAME, overwriting FILENAME if necessary. If FILENAME is false, then write the history list to ~/.history. Returns true if successful, or false if not.

append_history(NELEMENTS [,FILENAME])

int     append_history(int nelements, str filename = '~/.history')

history_truncate_file([FILENAME [,NLINES]])

int     history_truncate_file(str filename = '~/.history',
                              int nlines = 0)

History Expansion

history_expand(STRING)

(int result, str expansion) history_expand(str string)

Note that this function returns expansion in the scalar context.

get_history_event(STRING, CINDEX [,QCHAR])

(str text, int cindex) = get_history_event(str  string,
                                           int  cindex,
                                           char qchar = '\0')

history_tokenize(STRING)

(@str)  history_tokenize(str string)

history_arg_extract(STRING, [FIRST [,LAST]])

str history_arg_extract(str string, int first = 0, int last = '$')

Term::ReadLine::Gnu Variables

Following GNU Readline/History Library variables can be accessed by a Perl program. See GNU Readline Library Manual and GNU History Library Manual for details of each variable. You can access them by using Attribs methods. Names of keys in this hash conform to standard conventions with the leading rl_ stripped.

Examples:

$attribs = $term->Attribs;
$v = $attribs->{library_version};   # rl_library_version
$v = $attribs->{history_base};      # history_base

Readline Variables

str rl_line_buffer
int rl_point
int rl_end
int rl_mark
int rl_done
int rl_eof_found (GRL 8.2)
int rl_num_chars_to_read (GRL 4.1)
int rl_pending_input
int rl_dispatching
int rl_erase_empty_line (GRL 4.0)
str rl_prompt (read only)
str rl_display_prompt
int rl_already_prompted (GRL 4.1)
str rl_library_version (read only)
int rl_readline_version (read only)
int rl_gnu_readline_p (GRL 4.1, read only)
str rl_terminal_name
str rl_readline_name
filehandle rl_instream
filehandle rl_outstream
int rl_prefer_env_winsize (GRL 5.1)
pfunc rl_last_func (GRL 4.2, read only)
pfunc rl_startup_hook
pfunc rl_pre_input_hook (GRL 4.0)
pfunc rl_event_hook
pfunc rl_getc_function
pfunc rl_signal_event_hook (GRL 6.3)
pfunc rl_timeout_event_hook (GRL 8.2)
pfunc rl_input_available_hook (GRL 6.3)
pfunc rl_redisplay_function
pfunc rl_prep_term_function (GRL 2.1)
pfunc rl_deprep_term_function (GRL 2.1)
Keymap rl_executing_keymap (read only)
Keymap rl_binding_keymap (read only)
str rl_executing_macro (GRL 4.2, read only)
int rl_executing_key (GRL 6.3, read only)
str rl_executing_keyseq (GRL 6.3, read only)
int rl_key_sequence_length (read only)
int rl_readline_state (GRL 4.2)
int rl_explicit_arg (read only)
int rl_numeric_arg (read only)
int rl_editing_mode (read only)

Signal Handling Variables

int rl_catch_signals (GRL 4.0)
int rl_catch_sigwinch (GRL 4.0)
int rl_persistent_signal_handlers (GRL 7.0)
int rl_change_environment (GRL 6.3)

Completion Variables

pfunc rl_completion_entry_function
pfunc rl_attempted_completion_function
pfunc rl_filename_quoting_function
pfunc rl_filename_dequoting_function
pfunc rl_char_is_quoted_p
pfunc rl_ignore_some_completions_function
pfunc rl_directory_completion_hook
pfunc rl_directory_rewrite_hook (GRL 4.2)
pfunc rl_filename_stat_hook (GRL 6.3)
pfunc rl_filename_rewrite_hook (GRL 6.1)
pfunc rl_completion_display_matches_hook (GRL 4.0)
str rl_basic_word_break_characters
str rl_basic_quote_characters
str rl_completer_word_break_characters
pfunc rl_completion_word_break_hook (GRL 5.0)
str rl_completer_quote_characters
str rl_filename_quote_characters
str rl_special_prefixes
int rl_completion_query_items
int rl_completion_append_character
int rl_completion_suppress_append (GRL 4.3)
int rl_completion_quote_character (GRL 5.0, read only)
int rl_completion_suppress_quote (GRL 5.0)
int rl_completion_found_quote (GRL 5.0, read only)
int rl_completion_mark_symlink_dirs (GRL 4.3)
int rl_ignore_completion_duplicates
int rl_filename_completion_desired
int rl_filename_quoting_desired
int rl_attempted_completion_over
int rl_sort_completion_matches (GRL 6.0)
int rl_completion_type (read only)
int rl_completion_invoking_key (GRL 6.0, read only)
int rl_inhibit_completion

History Variables

int history_base
int history_length
int history_max_entries (called `max_input_history', read only)
int history_write_timestamps (GRL 5.0)
char history_expansion_char
char history_subst_char
char history_comment_char
str history_word_delimiters (GRL 4.2)
str history_search_delimiter_chars
str history_no_expand_chars
int history_quotes_inhibit_expansion
int history_quoting_state
pfunc history_inhibit_expansion_function

Function References

rl_getc
rl_redisplay
rl_callback_read_char
rl_display_match_list
rl_filename_completion_function
rl_username_completion_function
list_completion_function
shadow_redisplay
Tk_getc

Custom Completion

In this section variables and functions for custom completion are described along with examples.

Most of descriptions in this section came from GNU Readline Library Manual.

completion_entry_function

This variable holds reference refers to a generator function for completion_matches().

A generator function is called repeatedly from completion_matches(), returning a string each time. The arguments to the generator function are TEXT and STATE. TEXT is the partial word to be completed. STATE is zero the first time the function is called, allowing the generator to perform any necessary initialization, and a positive non-zero integer for each subsequent call. When the generator function returns undef this signals completion_matches() that there are no more possibilities left.

If this variable set to undef, built-in filename_completion_function is used.

A sample generator function, list_completion_function, is defined in Gnu.pm. You can use it as follows;

use Term::ReadLine;
...
my $term = new Term::ReadLine 'sample';
my $attribs = $term->Attribs;
...
$attribs->{completion_entry_function} =
    $attribs->{list_completion_function};
...
$attribs->{completion_word} =
    [qw(reference to a list of words which you want to use for completion)];
$term->readline("custom completion>");

See also completion_matches.

attempted_completion_function

A reference to an alternative function to create matches.

The function is called with TEXT, LINE_BUFFER, START, and END. LINE_BUFFER is a current input buffer string. START and END are indices in LINE_BUFFER saying what the boundaries of TEXT are.

If this function exists and returns null list or undef, or if this variable is set to undef, then an internal function rl_complete() will call the value of completion_entry_function to generate matches, otherwise the array of strings returned will be used.

The default value of this variable is undef. You can use it as follows;

use Term::ReadLine;
...
my $term = new Term::ReadLine 'sample';
my $attribs = $term->Attribs;
...
sub sample_completion {
    my ($text, $line, $start, $end) = @_;
    # If first word then username completion, else filename completion
    if (substr($line, 0, $start) =~ /^\s*$/) {
        return $term->completion_matches($text,
                                         $attribs->{'username_completion_function'});
    } else {
        return ();
    }
}
...
$attribs->{attempted_completion_function} = \&sample_completion;

completion_matches(TEXT, ENTRY_FUNC)

Returns an array of strings which is a list of completions for TEXT. If there are no completions, returns undef. The first entry in the returned array is the substitution for TEXT. The remaining entries are the possible completions.

ENTRY_FUNC is a generator function which has two arguments, and returns a string. The first argument is TEXT. The second is a state argument; it is zero on the first call, and non-zero on subsequent calls. ENTRY_FUNC returns undef to the caller when there are no more matches.

If the value of ENTRY_FUNC is undef, built-in filename_completion_function is used.

completion_matches is a Perl wrapper function of an internal function completion_matches(). See also completion_entry_function.

completion_function

A variable whose content is a reference to a function which returns a list of candidates to complete.

This variable is compatible with Term::ReadLine::Perl and very easy to use.

use Term::ReadLine;
...
my $term = new Term::ReadLine 'sample';
my $attribs = $term->Attribs;
...
$attribs->{completion_function} = sub {
    my ($text, $line, $start) = @_;
    return qw(a list of candidates to complete);
};

list_completion_function(TEXT, STATE)

A sample generator function defined by Term::ReadLine::Gnu. Example code at completion_entry_function shows how to use this function.

Term::ReadLine::Gnu Specific Features

Term::ReadLine::Gnu Specific Functions

CallbackHandlerInstall(PROMPT, LHANDLER)

This method provides the function rl_callback_handler_install() with the following additional feature compatible with readline method; ornament feature, Term::ReadLine::Perl compatible completion function, history expansion, and addition to history buffer.

call_function(FUNCTION, [COUNT [,KEY]])

int     rl_call_function(FunctionPtr|str function, count = 1, key = -1)

get_all_function_names

Returns a list of all function names.

shadow_redisplay

A redisplay function for password input. You can use it as follows;

$attribs->{redisplay_function} = $attribs->{shadow_redisplay};
$line = $term->readline("password> ");

filename_list

Returns candidates of filenames to complete. This function can be used with completion_function and is implemented for the compatibility with Term::ReadLine::Perl.

list_completion_function

See the description of section "Custom Completion".

Term::ReadLine::Gnu Specific Variables

do_expand

When true, the history expansion is enabled. By default false.

completion_function

See the description of section "Custom Completion".

completion_word

A reference to a list of candidates to complete for list_completion_function.

Term::ReadLine::Gnu Specific Commands

history-expand-line

The equivalent of the Bash history-expand-line editing command.

operate-and-get-next

The equivalent of the Korn shell operate-and-get-next-history-line editing command and the Bash operate-and-get-next.

This command is bound to \C-o by default for the compatibility with the Bash and Term::ReadLine::Perl.

display-readline-version

Shows the version of Term::ReadLine::Gnu and the one of the GNU Readline Library.

change-ornaments

Change ornaments interactively.

FILES

~/.inputrc

Readline init file. Using this file it is possible that you would like to use a different set of key bindings. When a program which uses the GNU Readline library starts up, the init file is read, and the key bindings are set.

The conditional init constructs is supported. The program name which is specified by the first argument of new method is used as the application construct.

For example, when your program calls new method as follows;

...
$term = new Term::ReadLine 'PerlSh';
...

your ~/.inputrc can define key bindings only for the program as follows;

...
$if PerlSh
Meta-Rubout: backward-kill-word
"\C-x\C-r": re-read-init-file
"\e[11~": "Function Key 1"
$endif
...

For further details, see the section "Readline Init File" in the GNU Readline Library Manual

EXPORTS

No symbols are exported by default. The following tags are defined and their symbols can be exported.

prompt

RL_PROMPT_START_IGNORE RL_PROMPT_END_IGNORE

match_type

NO_MATCH SINGLE_MATCH MULT_MATCH

keymap_type

ISFUNC ISKMAP ISMACR

undo_code

UNDO_DELETE UNDO_INSERT UNDO_BEGIN UNDO_END

rl_state

RL_STATE_NONE RL_STATE_INITIALIZING RL_STATE_INITIALIZED RL_STATE_TERMPREPPED RL_STATE_READCMD RL_STATE_METANEXT RL_STATE_DISPATCHING RL_STATE_MOREINPUT RL_STATE_ISEARCH RL_STATE_NSEARCH RL_STATE_SEARCH RL_STATE_NUMERICARG RL_STATE_MACROINPUT RL_STATE_MACRODEF RL_STATE_OVERWRITE RL_STATE_COMPLETING RL_STATE_SIGHANDLER RL_STATE_UNDOING RL_STATE_INPUTPENDING RL_STATE_TTYCSAVED RL_STATE_CALLBACK RL_STATE_VIMOTION RL_STATE_MULTIKEY RL_STATE_VICMDONCE RL_STATE_CHARSEARCH RL_STATE_REDISPLAYING RL_STATE_DONE RL_STATE_TIMEOUT RL_STATE_EOF

They can be exported as follows;

use Term::ReadLine;
BEGIN {
    import Term::ReadLine::Gnu qw(:keymap_type RL_STATE_INITIALIZED);
}

ENVIRONMENT

The environment variable PERL_RL governs which ReadLine clone is loaded. See the ENVIRONMENT section on Term::ReadLine for further details.

If the environment variable TERM is set to "emacs" or the environment variable INSIDE_EMACS or EMACS is defined, Term::ReadLine::Stub is used instead of <Term::ReadLine:Gnu>.

SEE ALSO

Term::ReadLine::Gnu Project Home Page

GNU Readline Library Manual

GNU History Library Manual

Sample and test programs (eg/* and t/*) in the Term::ReadLine::Gnu distribution

Term::ReadLine

Works which use Term::ReadLine::Gnu

Distributions which depend on Term::ReadLine::Gnu on CPAN

https://metacpan.org/requires/distribution/Term-ReadLine-Gnu

Perl Debugger

perl -d

Perl Shell (psh)

The Perl Shell is a shell that combines the interactive nature of a Unix shell with the power of Perl.

A programmable completion feature compatible with bash is implemented.

SPP (Synopsys Plus Perl)

SPP (Synopsys Plus Perl) is a Perl module that wraps around Synopsys' shell programs. SPP is inspired by the original dc_perl written by Steve Golson, but it's an entirely new implementation. Why is it called SPP and not dc_perl? Well, SPP was written to wrap around any of Synopsys' shells.

PFM (Personal File Manager for Unix/Linux)

Pfm is a terminal-based file manager written in Perl, based on PFM.COM for MS-DOS (originally by Paul Culley and Henk de Heer).

The soundgrab

soundgrab is designed to help you slice up a big long raw audio file (by default 44.1 kHz 2 channel signed sixteen bit little endian) and save your favorite sections to other files. It does this by providing you with a cassette player like command line interface.

PDL (The Perl Data Language)

PDL (``Perl Data Language'') gives standard Perl the ability to compactly store and speedily manipulate the large N-dimensional data arrays which are the bread and butter of scientific computing.

PIQT (Perl Interactive DBI Query Tool)

PIQT is an interactive query tool using the Perl DBI database interface. It supports ReadLine, provides a built in scripting language with a Lisp like syntax, an online help system, and uses wrappers to interface to the DBD modules.

vshnu (the New Visual Shell)

A visual shell and CLI shell supplement.

If you know any other works you recommend, please let me know.

AUTHOR

Hiroo Hayashi <hiroo.hayashi@computer.org>

http://search.cpan.org/~hayashi/

TODO

GTK+ support in addition to Tk.

BUGS

Submit a bug report to the bug tracker on GitHub.

add_defun() can define up to 16 functions.

Some functions and variables do not have test code yet. Your contribution is welcome. See t/readline.t for details.

If the pager command (| or ||) in Perl debugger causes segmentation fault, you need to fix perl5db.pl. See https://rt.perl.org/Public/Bug/Display.html?id=121456 for details.

LICENSE

Copyright (c) 1996-2020 Hiroo Hayashi. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

cpanm Term::ReadLine::Gnu

perl -MCPAN -e shell
install Term::ReadLine::Gnu