1 @comment %**start of header (This is for running Texinfo on a region.)
2 @setfilename rltech.info
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6 This document describes the GNU Readline Library, a utility for aiding
7 in the consistency of user interface across discrete programs that need
8 to provide a command line interface.
10 Copyright (C) 1988--2016 Free Software Foundation, Inc.
12 Permission is granted to make and distribute verbatim copies of
13 this manual provided the copyright notice and this permission notice
14 pare preserved on all copies.
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19 notice identical to this one except for the removal of this paragraph
20 (this paragraph not being relevant to the printed manual).
23 Permission is granted to copy and distribute modified versions of this
24 manual under the conditions for verbatim copying, provided that the entire
25 resulting derived work is distributed under the terms of a permission
26 notice identical to this one.
28 Permission is granted to copy and distribute translations of this manual
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30 except that this permission notice may be stated in a translation approved
34 @node Programming with GNU Readline
35 @chapter Programming with GNU Readline
37 This chapter describes the interface between the @sc{gnu} Readline Library and
38 other programs. If you are a programmer, and you wish to include the
39 features found in @sc{gnu} Readline
40 such as completion, line editing, and interactive history manipulation
41 in your own programs, this section is for you.
44 * Basic Behavior:: Using the default behavior of Readline.
45 * Custom Functions:: Adding your own functions to Readline.
46 * Readline Variables:: Variables accessible to custom
48 * Readline Convenience Functions:: Functions which Readline supplies to
49 aid in writing your own custom
51 * Readline Signal Handling:: How Readline behaves when it receives signals.
52 * Custom Completers:: Supplanting or supplementing Readline's
57 @section Basic Behavior
59 Many programs provide a command line interface, such as @code{mail},
60 @code{ftp}, and @code{sh}. For such programs, the default behaviour of
61 Readline is sufficient. This section describes how to use Readline in
62 the simplest way possible, perhaps to replace calls in your code to
63 @code{gets()} or @code{fgets()}.
66 @cindex readline, function
68 The function @code{readline()} prints a prompt @var{prompt}
69 and then reads and returns a single line of text from the user.
70 If @var{prompt} is @code{NULL} or the empty string, no prompt is displayed.
71 The line @code{readline} returns is allocated with @code{malloc()};
72 the caller should @code{free()} the line when it has finished with it.
73 The declaration for @code{readline} in ANSI C is
76 @code{char *readline (const char *@var{prompt});}
82 @code{char *line = readline ("Enter a line: ");}
85 in order to read a line of text from the user.
86 The line returned has the final newline removed, so only the
89 If @code{readline} encounters an @code{EOF} while reading the line, and the
90 line is empty at that point, then @code{(char *)NULL} is returned.
91 Otherwise, the line is ended just as if a newline had been typed.
93 If you want the user to be able to get at the line later, (with
94 @key{C-p} for example), you must call @code{add_history()} to save the
95 line away in a @dfn{history} list of such lines.
98 @code{add_history (line)};
102 For full details on the GNU History Library, see the associated manual.
104 It is preferable to avoid saving empty lines on the history list, since
105 users rarely have a burning need to reuse a blank line. Here is
106 a function which usefully replaces the standard @code{gets()} library
107 function, and has the advantage of no static buffer to overflow:
110 /* A static variable for holding the line. */
111 static char *line_read = (char *)NULL;
113 /* Read a string, and return a pointer to it.
114 Returns NULL on EOF. */
118 /* If the buffer has already been allocated,
119 return the memory to the free pool. */
123 line_read = (char *)NULL;
126 /* Get a line from the user. */
127 line_read = readline ("");
129 /* If the line has any text in it,
130 save it on the history. */
131 if (line_read && *line_read)
132 add_history (line_read);
138 This function gives the user the default behaviour of @key{TAB}
139 completion: completion on file names. If you do not want Readline to
140 complete on filenames, you can change the binding of the @key{TAB} key
141 with @code{rl_bind_key()}.
144 @code{int rl_bind_key (int @var{key}, rl_command_func_t *@var{function});}
147 @code{rl_bind_key()} takes two arguments: @var{key} is the character that
148 you want to bind, and @var{function} is the address of the function to
149 call when @var{key} is pressed. Binding @key{TAB} to @code{rl_insert()}
150 makes @key{TAB} insert itself.
151 @code{rl_bind_key()} returns non-zero if @var{key} is not a valid
152 ASCII character code (between 0 and 255).
154 Thus, to disable the default @key{TAB} behavior, the following suffices:
156 @code{rl_bind_key ('\t', rl_insert);}
159 This code should be executed once at the start of your program; you
160 might write a function called @code{initialize_readline()} which
161 performs this and other desired initializations, such as installing
162 custom completers (@pxref{Custom Completers}).
164 @node Custom Functions
165 @section Custom Functions
167 Readline provides many functions for manipulating the text of
168 the line, but it isn't possible to anticipate the needs of all
169 programs. This section describes the various functions and variables
170 defined within the Readline library which allow a user program to add
171 customized functionality to Readline.
173 Before declaring any functions that customize Readline's behavior, or
174 using any functionality Readline provides in other code, an
175 application writer should include the file @code{<readline/readline.h>}
176 in any file that uses Readline's features. Since some of the definitions
177 in @code{readline.h} use the @code{stdio} library, the file
178 @code{<stdio.h>} should be included before @code{readline.h}.
180 @code{readline.h} defines a C preprocessor variable that should
181 be treated as an integer, @code{RL_READLINE_VERSION}, which may
182 be used to conditionally compile application code depending on
183 the installed Readline version. The value is a hexadecimal
184 encoding of the major and minor version numbers of the library,
185 of the form 0x@var{MMmm}. @var{MM} is the two-digit major
186 version number; @var{mm} is the two-digit minor version number.
187 For Readline 4.2, for example, the value of
188 @code{RL_READLINE_VERSION} would be @code{0x0402}.
191 * Readline Typedefs:: C declarations to make code readable.
192 * Function Writing:: Variables and calling conventions.
195 @node Readline Typedefs
196 @subsection Readline Typedefs
198 For readability, we declare a number of new object types, all pointers
201 The reason for declaring these new types is to make it easier to write
202 code describing pointers to C functions with appropriately prototyped
203 arguments and return values.
205 For instance, say we want to declare a variable @var{func} as a pointer
206 to a function which takes two @code{int} arguments and returns an
207 @code{int} (this is the type of all of the Readline bindable functions).
208 Instead of the classic C declaration
210 @code{int (*func)();}
213 or the ANSI-C style declaration
215 @code{int (*func)(int, int);}
220 @code{rl_command_func_t *func;}
222 The full list of function pointer types available is
225 @item typedef int rl_command_func_t (int, int);
227 @item typedef char *rl_compentry_func_t (const char *, int);
229 @item typedef char **rl_completion_func_t (const char *, int, int);
231 @item typedef char *rl_quote_func_t (char *, int, char *);
233 @item typedef char *rl_dequote_func_t (char *, int);
235 @item typedef int rl_compignore_func_t (char **);
237 @item typedef void rl_compdisp_func_t (char **, int, int);
239 @item typedef int rl_hook_func_t (void);
241 @item typedef int rl_getc_func_t (FILE *);
243 @item typedef int rl_linebuf_func_t (char *, int);
245 @item typedef int rl_intfunc_t (int);
246 @item #define rl_ivoidfunc_t rl_hook_func_t
247 @item typedef int rl_icpfunc_t (char *);
248 @item typedef int rl_icppfunc_t (char **);
250 @item typedef void rl_voidfunc_t (void);
251 @item typedef void rl_vintfunc_t (int);
252 @item typedef void rl_vcpfunc_t (char *);
253 @item typedef void rl_vcppfunc_t (char **);
257 @node Function Writing
258 @subsection Writing a New Function
260 In order to write new functions for Readline, you need to know the
261 calling conventions for keyboard-invoked functions, and the names of the
262 variables that describe the current state of the line read so far.
264 The calling sequence for a command @code{foo} looks like
267 @code{int foo (int count, int key)}
271 where @var{count} is the numeric argument (or 1 if defaulted) and
272 @var{key} is the key that invoked this function.
274 It is completely up to the function as to what should be done with the
275 numeric argument. Some functions use it as a repeat count, some
276 as a flag, and others to choose alternate behavior (refreshing the current
277 line as opposed to refreshing the screen, for example). Some choose to
278 ignore it. In general, if a
279 function uses the numeric argument as a repeat count, it should be able
280 to do something useful with both negative and positive arguments.
281 At the very least, it should be aware that it can be passed a
284 A command function should return 0 if its action completes successfully,
285 and a value greater than zero if some error occurs.
286 This is the convention obeyed by all of the builtin Readline bindable
289 @node Readline Variables
290 @section Readline Variables
292 These variables are available to function writers.
294 @deftypevar {char *} rl_line_buffer
295 This is the line gathered so far. You are welcome to modify the
296 contents of the line, but see @ref{Allowing Undoing}. The
297 function @code{rl_extend_line_buffer} is available to increase
298 the memory allocated to @code{rl_line_buffer}.
301 @deftypevar int rl_point
302 The offset of the current cursor position in @code{rl_line_buffer}
306 @deftypevar int rl_end
307 The number of characters present in @code{rl_line_buffer}. When
308 @code{rl_point} is at the end of the line, @code{rl_point} and
309 @code{rl_end} are equal.
312 @deftypevar int rl_mark
313 The @var{mark} (saved position) in the current line. If set, the mark
314 and point define a @emph{region}.
317 @deftypevar int rl_done
318 Setting this to a non-zero value causes Readline to return the current
322 @deftypevar int rl_num_chars_to_read
323 Setting this to a positive value before calling @code{readline()} causes
324 Readline to return after accepting that many characters, rather
325 than reading up to a character bound to @code{accept-line}.
328 @deftypevar int rl_pending_input
329 Setting this to a value makes it the next keystroke read. This is a
330 way to stuff a single character into the input stream.
333 @deftypevar int rl_dispatching
334 Set to a non-zero value if a function is being called from a key binding;
335 zero otherwise. Application functions can test this to discover whether
336 they were called directly or by Readline's dispatching mechanism.
339 @deftypevar int rl_erase_empty_line
340 Setting this to a non-zero value causes Readline to completely erase
341 the current line, including any prompt, any time a newline is typed as
342 the only character on an otherwise-empty line. The cursor is moved to
343 the beginning of the newly-blank line.
346 @deftypevar {char *} rl_prompt
347 The prompt Readline uses. This is set from the argument to
348 @code{readline()}, and should not be assigned to directly.
349 The @code{rl_set_prompt()} function (@pxref{Redisplay}) may
350 be used to modify the prompt string after calling @code{readline()}.
353 @deftypevar {char *} rl_display_prompt
354 The string displayed as the prompt. This is usually identical to
355 @var{rl_prompt}, but may be changed temporarily by functions that
356 use the prompt string as a message area, such as incremental search.
359 @deftypevar int rl_already_prompted
360 If an application wishes to display the prompt itself, rather than have
361 Readline do it the first time @code{readline()} is called, it should set
362 this variable to a non-zero value after displaying the prompt.
363 The prompt must also be passed as the argument to @code{readline()} so
364 the redisplay functions can update the display properly.
365 The calling application is responsible for managing the value; Readline
369 @deftypevar {const char *} rl_library_version
370 The version number of this revision of the library.
373 @deftypevar int rl_readline_version
374 An integer encoding the current version of the library. The encoding is
375 of the form 0x@var{MMmm}, where @var{MM} is the two-digit major version
376 number, and @var{mm} is the two-digit minor version number.
377 For example, for Readline-4.2, @code{rl_readline_version} would have the
381 @deftypevar {int} rl_gnu_readline_p
382 Always set to 1, denoting that this is @sc{gnu} readline rather than some
386 @deftypevar {const char *} rl_terminal_name
387 The terminal type, used for initialization. If not set by the application,
388 Readline sets this to the value of the @env{TERM} environment variable
389 the first time it is called.
392 @deftypevar {const char *} rl_readline_name
393 This variable is set to a unique name by each application using Readline.
394 The value allows conditional parsing of the inputrc file
395 (@pxref{Conditional Init Constructs}).
398 @deftypevar {FILE *} rl_instream
399 The stdio stream from which Readline reads input.
400 If @code{NULL}, Readline defaults to @var{stdin}.
403 @deftypevar {FILE *} rl_outstream
404 The stdio stream to which Readline performs output.
405 If @code{NULL}, Readline defaults to @var{stdout}.
408 @deftypevar int rl_prefer_env_winsize
409 If non-zero, Readline gives values found in the @env{LINES} and
410 @env{COLUMNS} environment variables greater precedence than values fetched
411 from the kernel when computing the screen dimensions.
414 @deftypevar {rl_command_func_t *} rl_last_func
415 The address of the last command function Readline executed. May be used to
416 test whether or not a function is being executed twice in succession, for
420 @deftypevar {rl_hook_func_t *} rl_startup_hook
421 If non-zero, this is the address of a function to call just
422 before @code{readline} prints the first prompt.
425 @deftypevar {rl_hook_func_t *} rl_pre_input_hook
426 If non-zero, this is the address of a function to call after
427 the first prompt has been printed and just before @code{readline}
428 starts reading input characters.
431 @deftypevar {rl_hook_func_t *} rl_event_hook
432 If non-zero, this is the address of a function to call periodically
433 when Readline is waiting for terminal input.
434 By default, this will be called at most ten times a second if there
435 is no keyboard input.
438 @deftypevar {rl_getc_func_t *} rl_getc_function
439 If non-zero, Readline will call indirectly through this pointer
440 to get a character from the input stream. By default, it is set to
441 @code{rl_getc}, the default Readline character input function
442 (@pxref{Character Input}).
443 In general, an application that sets @var{rl_getc_function} should consider
444 setting @var{rl_input_available_hook} as well.
447 @deftypevar {rl_hook_func_t *} rl_signal_event_hook
448 If non-zero, this is the address of a function to call if a read system
449 call is interrupted when Readline is reading terminal input.
452 @deftypevar {rl_hook_func_t *} rl_input_available_hook
453 If non-zero, Readline will use this function's return value when it needs
454 to determine whether or not there is available input on the current input
456 The default hook checks @code{rl_instream}; if an application is using a
457 different input source, it should set the hook appropriately.
458 Readline queries for available input when implementing intra-key-sequence
459 timeouts during input and incremental searches.
460 This may use an application-specific timeout before returning a value;
461 Readline uses the value passed to @code{rl_set_keyboard_input_timeout()}
462 or the value of the user-settable @var{keyseq-timeout} variable.
463 This is designed for use by applications using Readline's callback interface
464 (@pxref{Alternate Interface}), which may not use the traditional
465 @code{read(2)} and file descriptor interface, or other applications using
466 a different input mechanism.
467 If an application uses an input mechanism or hook that can potentially exceed
468 the value of @var{keyseq-timeout}, it should increase the timeout or set
469 this hook appropriately even when not using the callback interface.
470 In general, an application that sets @var{rl_getc_function} should consider
471 setting @var{rl_input_available_hook} as well.
474 @deftypevar {rl_voidfunc_t *} rl_redisplay_function
475 If non-zero, Readline will call indirectly through this pointer
476 to update the display with the current contents of the editing buffer.
477 By default, it is set to @code{rl_redisplay}, the default Readline
478 redisplay function (@pxref{Redisplay}).
481 @deftypevar {rl_vintfunc_t *} rl_prep_term_function
482 If non-zero, Readline will call indirectly through this pointer
483 to initialize the terminal. The function takes a single argument, an
484 @code{int} flag that says whether or not to use eight-bit characters.
485 By default, this is set to @code{rl_prep_terminal}
486 (@pxref{Terminal Management}).
489 @deftypevar {rl_voidfunc_t *} rl_deprep_term_function
490 If non-zero, Readline will call indirectly through this pointer
491 to reset the terminal. This function should undo the effects of
492 @code{rl_prep_term_function}.
493 By default, this is set to @code{rl_deprep_terminal}
494 (@pxref{Terminal Management}).
497 @deftypevar {Keymap} rl_executing_keymap
498 This variable is set to the keymap (@pxref{Keymaps}) in which the
499 currently executing readline function was found.
502 @deftypevar {Keymap} rl_binding_keymap
503 This variable is set to the keymap (@pxref{Keymaps}) in which the
504 last key binding occurred.
507 @deftypevar {char *} rl_executing_macro
508 This variable is set to the text of any currently-executing macro.
511 @deftypevar int rl_executing_key
512 The key that caused the dispatch to the currently-executing Readline function.
515 @deftypevar {char *} rl_executing_keyseq
516 The full key sequence that caused the dispatch to the currently-executing
520 @deftypevar int rl_key_sequence_length
521 The number of characters in @var{rl_executing_keyseq}.
524 @deftypevar {int} rl_readline_state
525 A variable with bit values that encapsulate the current Readline state.
526 A bit is set with the @code{RL_SETSTATE} macro, and unset with the
527 @code{RL_UNSETSTATE} macro. Use the @code{RL_ISSTATE} macro to test
528 whether a particular state bit is set. Current state bits include:
532 Readline has not yet been called, nor has it begun to initialize.
533 @item RL_STATE_INITIALIZING
534 Readline is initializing its internal data structures.
535 @item RL_STATE_INITIALIZED
536 Readline has completed its initialization.
537 @item RL_STATE_TERMPREPPED
538 Readline has modified the terminal modes to do its own input and redisplay.
539 @item RL_STATE_READCMD
540 Readline is reading a command from the keyboard.
541 @item RL_STATE_METANEXT
542 Readline is reading more input after reading the meta-prefix character.
543 @item RL_STATE_DISPATCHING
544 Readline is dispatching to a command.
545 @item RL_STATE_MOREINPUT
546 Readline is reading more input while executing an editing command.
547 @item RL_STATE_ISEARCH
548 Readline is performing an incremental history search.
549 @item RL_STATE_NSEARCH
550 Readline is performing a non-incremental history search.
551 @item RL_STATE_SEARCH
552 Readline is searching backward or forward through the history for a string.
553 @item RL_STATE_NUMERICARG
554 Readline is reading a numeric argument.
555 @item RL_STATE_MACROINPUT
556 Readline is currently getting its input from a previously-defined keyboard
558 @item RL_STATE_MACRODEF
559 Readline is currently reading characters defining a keyboard macro.
560 @item RL_STATE_OVERWRITE
561 Readline is in overwrite mode.
562 @item RL_STATE_COMPLETING
563 Readline is performing word completion.
564 @item RL_STATE_SIGHANDLER
565 Readline is currently executing the readline signal handler.
566 @item RL_STATE_UNDOING
567 Readline is performing an undo.
568 @item RL_STATE_INPUTPENDING
569 Readline has input pending due to a call to @code{rl_execute_next()}.
570 @item RL_STATE_TTYCSAVED
571 Readline has saved the values of the terminal's special characters.
572 @item RL_STATE_CALLBACK
573 Readline is currently using the alternate (callback) interface
574 (@pxref{Alternate Interface}).
575 @item RL_STATE_VIMOTION
576 Readline is reading the argument to a vi-mode "motion" command.
577 @item RL_STATE_MULTIKEY
578 Readline is reading a multiple-keystroke command.
579 @item RL_STATE_VICMDONCE
580 Readline has entered vi command (movement) mode at least one time during
581 the current call to @code{readline()}.
583 Readline has read a key sequence bound to @code{accept-line}
584 and is about to return the line to the caller.
589 @deftypevar {int} rl_explicit_arg
590 Set to a non-zero value if an explicit numeric argument was specified by
591 the user. Only valid in a bindable command function.
594 @deftypevar {int} rl_numeric_arg
595 Set to the value of any numeric argument explicitly specified by the user
596 before executing the current Readline function. Only valid in a bindable
600 @deftypevar {int} rl_editing_mode
601 Set to a value denoting Readline's current editing mode. A value of
602 @var{1} means Readline is currently in emacs mode; @var{0}
603 means that vi mode is active.
607 @node Readline Convenience Functions
608 @section Readline Convenience Functions
611 * Function Naming:: How to give a function you write a name.
612 * Keymaps:: Making keymaps.
613 * Binding Keys:: Changing Keymaps.
614 * Associating Function Names and Bindings:: Translate function names to
616 * Allowing Undoing:: How to make your functions undoable.
617 * Redisplay:: Functions to control line display.
618 * Modifying Text:: Functions to modify @code{rl_line_buffer}.
619 * Character Input:: Functions to read keyboard input.
620 * Terminal Management:: Functions to manage terminal settings.
621 * Utility Functions:: Generally useful functions and hooks.
622 * Miscellaneous Functions:: Functions that don't fall into any category.
623 * Alternate Interface:: Using Readline in a `callback' fashion.
624 * A Readline Example:: An example Readline function.
625 * Alternate Interface Example:: An example program using the alternate interface.
628 @node Function Naming
629 @subsection Naming a Function
631 The user can dynamically change the bindings of keys while using
632 Readline. This is done by representing the function with a descriptive
633 name. The user is able to type the descriptive name when referring to
634 the function. Thus, in an init file, one might find
637 Meta-Rubout: backward-kill-word
640 This binds the keystroke @key{Meta-Rubout} to the function
641 @emph{descriptively} named @code{backward-kill-word}. You, as the
642 programmer, should bind the functions you write to descriptive names as
643 well. Readline provides a function for doing that:
645 @deftypefun int rl_add_defun (const char *name, rl_command_func_t *function, int key)
646 Add @var{name} to the list of named functions. Make @var{function} be
647 the function that gets called. If @var{key} is not -1, then bind it to
648 @var{function} using @code{rl_bind_key()}.
651 Using this function alone is sufficient for most applications.
652 It is the recommended way to add a few functions to the default
653 functions that Readline has built in.
654 If you need to do something other than adding a function to Readline,
655 you may need to use the underlying functions described below.
658 @subsection Selecting a Keymap
660 Key bindings take place on a @dfn{keymap}. The keymap is the
661 association between the keys that the user types and the functions that
662 get run. You can make your own keymaps, copy existing keymaps, and tell
663 Readline which keymap to use.
665 @deftypefun Keymap rl_make_bare_keymap (void)
666 Returns a new, empty keymap. The space for the keymap is allocated with
667 @code{malloc()}; the caller should free it by calling
668 @code{rl_free_keymap()} when done.
671 @deftypefun Keymap rl_copy_keymap (Keymap map)
672 Return a new keymap which is a copy of @var{map}.
675 @deftypefun Keymap rl_make_keymap (void)
676 Return a new keymap with the printing characters bound to rl_insert,
677 the lowercase Meta characters bound to run their equivalents, and
678 the Meta digits bound to produce numeric arguments.
681 @deftypefun void rl_discard_keymap (Keymap keymap)
682 Free the storage associated with the data in @var{keymap}.
683 The caller should free @var{keymap}.
686 @deftypefun void rl_free_keymap (Keymap keymap)
687 Free all storage associated with @var{keymap}. This calls
688 @code{rl_discard_keymap} to free subordindate keymaps and macros.
691 Readline has several internal keymaps. These functions allow you to
692 change which keymap is active.
694 @deftypefun Keymap rl_get_keymap (void)
695 Returns the currently active keymap.
698 @deftypefun void rl_set_keymap (Keymap keymap)
699 Makes @var{keymap} the currently active keymap.
702 @deftypefun Keymap rl_get_keymap_by_name (const char *name)
703 Return the keymap matching @var{name}. @var{name} is one which would
704 be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
707 @deftypefun {char *} rl_get_keymap_name (Keymap keymap)
708 Return the name matching @var{keymap}. @var{name} is one which would
709 be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
713 @subsection Binding Keys
715 Key sequences are associate with functions through the keymap.
716 Readline has several internal keymaps: @code{emacs_standard_keymap},
717 @code{emacs_meta_keymap}, @code{emacs_ctlx_keymap},
718 @code{vi_movement_keymap}, and @code{vi_insertion_keymap}.
719 @code{emacs_standard_keymap} is the default, and the examples in
720 this manual assume that.
722 Since @code{readline()} installs a set of default key bindings the first
723 time it is called, there is always the danger that a custom binding
724 installed before the first call to @code{readline()} will be overridden.
725 An alternate mechanism is to install custom key bindings in an
726 initialization function assigned to the @code{rl_startup_hook} variable
727 (@pxref{Readline Variables}).
729 These functions manage key bindings.
731 @deftypefun int rl_bind_key (int key, rl_command_func_t *function)
732 Binds @var{key} to @var{function} in the currently active keymap.
733 Returns non-zero in the case of an invalid @var{key}.
736 @deftypefun int rl_bind_key_in_map (int key, rl_command_func_t *function, Keymap map)
737 Bind @var{key} to @var{function} in @var{map}.
738 Returns non-zero in the case of an invalid @var{key}.
741 @deftypefun int rl_bind_key_if_unbound (int key, rl_command_func_t *function)
742 Binds @var{key} to @var{function} if it is not already bound in the
743 currently active keymap.
744 Returns non-zero in the case of an invalid @var{key} or if @var{key} is
748 @deftypefun int rl_bind_key_if_unbound_in_map (int key, rl_command_func_t *function, Keymap map)
749 Binds @var{key} to @var{function} if it is not already bound in @var{map}.
750 Returns non-zero in the case of an invalid @var{key} or if @var{key} is
754 @deftypefun int rl_unbind_key (int key)
755 Bind @var{key} to the null function in the currently active keymap.
756 Returns non-zero in case of error.
759 @deftypefun int rl_unbind_key_in_map (int key, Keymap map)
760 Bind @var{key} to the null function in @var{map}.
761 Returns non-zero in case of error.
764 @deftypefun int rl_unbind_function_in_map (rl_command_func_t *function, Keymap map)
765 Unbind all keys that execute @var{function} in @var{map}.
768 @deftypefun int rl_unbind_command_in_map (const char *command, Keymap map)
769 Unbind all keys that are bound to @var{command} in @var{map}.
772 @deftypefun int rl_bind_keyseq (const char *keyseq, rl_command_func_t *function)
773 Bind the key sequence represented by the string @var{keyseq} to the function
774 @var{function}, beginning in the current keymap.
775 This makes new keymaps as necessary.
776 The return value is non-zero if @var{keyseq} is invalid.
779 @deftypefun int rl_bind_keyseq_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
780 Bind the key sequence represented by the string @var{keyseq} to the function
781 @var{function}. This makes new keymaps as necessary.
782 Initial bindings are performed in @var{map}.
783 The return value is non-zero if @var{keyseq} is invalid.
786 @deftypefun int rl_set_key (const char *keyseq, rl_command_func_t *function, Keymap map)
787 Equivalent to @code{rl_bind_keyseq_in_map}.
790 @deftypefun int rl_bind_keyseq_if_unbound (const char *keyseq, rl_command_func_t *function)
791 Binds @var{keyseq} to @var{function} if it is not already bound in the
792 currently active keymap.
793 Returns non-zero in the case of an invalid @var{keyseq} or if @var{keyseq} is
797 @deftypefun int rl_bind_keyseq_if_unbound_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
798 Binds @var{keyseq} to @var{function} if it is not already bound in @var{map}.
799 Returns non-zero in the case of an invalid @var{keyseq} or if @var{keyseq} is
803 @deftypefun int rl_generic_bind (int type, const char *keyseq, char *data, Keymap map)
804 Bind the key sequence represented by the string @var{keyseq} to the arbitrary
805 pointer @var{data}. @var{type} says what kind of data is pointed to by
806 @var{data}; this can be a function (@code{ISFUNC}), a macro
807 (@code{ISMACR}), or a keymap (@code{ISKMAP}). This makes new keymaps as
808 necessary. The initial keymap in which to do bindings is @var{map}.
811 @deftypefun int rl_parse_and_bind (char *line)
812 Parse @var{line} as if it had been read from the @code{inputrc} file and
813 perform any key bindings and variable assignments found
814 (@pxref{Readline Init File}).
817 @deftypefun int rl_read_init_file (const char *filename)
818 Read keybindings and variable assignments from @var{filename}
819 (@pxref{Readline Init File}).
822 @node Associating Function Names and Bindings
823 @subsection Associating Function Names and Bindings
825 These functions allow you to find out what keys invoke named functions
826 and the functions invoked by a particular key sequence. You may also
827 associate a new function name with an arbitrary function.
829 @deftypefun {rl_command_func_t *} rl_named_function (const char *name)
830 Return the function with name @var{name}.
833 @deftypefun {rl_command_func_t *} rl_function_of_keyseq (const char *keyseq, Keymap map, int *type)
834 Return the function invoked by @var{keyseq} in keymap @var{map}.
835 If @var{map} is @code{NULL}, the current keymap is used. If @var{type} is
836 not @code{NULL}, the type of the object is returned in the @code{int} variable
837 it points to (one of @code{ISFUNC}, @code{ISKMAP}, or @code{ISMACR}).
840 @deftypefun {char **} rl_invoking_keyseqs (rl_command_func_t *function)
841 Return an array of strings representing the key sequences used to
842 invoke @var{function} in the current keymap.
845 @deftypefun {char **} rl_invoking_keyseqs_in_map (rl_command_func_t *function, Keymap map)
846 Return an array of strings representing the key sequences used to
847 invoke @var{function} in the keymap @var{map}.
850 @deftypefun void rl_function_dumper (int readable)
851 Print the readline function names and the key sequences currently
852 bound to them to @code{rl_outstream}. If @var{readable} is non-zero,
853 the list is formatted in such a way that it can be made part of an
854 @code{inputrc} file and re-read.
857 @deftypefun void rl_list_funmap_names (void)
858 Print the names of all bindable Readline functions to @code{rl_outstream}.
861 @deftypefun {const char **} rl_funmap_names (void)
862 Return a NULL terminated array of known function names. The array is
863 sorted. The array itself is allocated, but not the strings inside. You
864 should free the array, but not the pointers, using @code{free} or
865 @code{rl_free} when you are done.
868 @deftypefun int rl_add_funmap_entry (const char *name, rl_command_func_t *function)
869 Add @var{name} to the list of bindable Readline command names, and make
870 @var{function} the function to be called when @var{name} is invoked.
873 @node Allowing Undoing
874 @subsection Allowing Undoing
876 Supporting the undo command is a painless thing, and makes your
877 functions much more useful. It is certainly easy to try
878 something if you know you can undo it.
880 If your function simply inserts text once, or deletes text once, and
881 uses @code{rl_insert_text()} or @code{rl_delete_text()} to do it, then
882 undoing is already done for you automatically.
884 If you do multiple insertions or multiple deletions, or any combination
885 of these operations, you should group them together into one operation.
886 This is done with @code{rl_begin_undo_group()} and
887 @code{rl_end_undo_group()}.
889 The types of events that can be undone are:
892 enum undo_code @{ UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END @};
895 Notice that @code{UNDO_DELETE} means to insert some text, and
896 @code{UNDO_INSERT} means to delete some text. That is, the undo code
897 tells what to undo, not how to undo it. @code{UNDO_BEGIN} and
898 @code{UNDO_END} are tags added by @code{rl_begin_undo_group()} and
899 @code{rl_end_undo_group()}.
901 @deftypefun int rl_begin_undo_group (void)
902 Begins saving undo information in a group construct. The undo
903 information usually comes from calls to @code{rl_insert_text()} and
904 @code{rl_delete_text()}, but could be the result of calls to
905 @code{rl_add_undo()}.
908 @deftypefun int rl_end_undo_group (void)
909 Closes the current undo group started with @code{rl_begin_undo_group
910 ()}. There should be one call to @code{rl_end_undo_group()}
911 for each call to @code{rl_begin_undo_group()}.
914 @deftypefun void rl_add_undo (enum undo_code what, int start, int end, char *text)
915 Remember how to undo an event (according to @var{what}). The affected
916 text runs from @var{start} to @var{end}, and encompasses @var{text}.
919 @deftypefun void rl_free_undo_list (void)
920 Free the existing undo list.
923 @deftypefun int rl_do_undo (void)
924 Undo the first thing on the undo list. Returns @code{0} if there was
925 nothing to undo, non-zero if something was undone.
928 Finally, if you neither insert nor delete text, but directly modify the
929 existing text (e.g., change its case), call @code{rl_modifying()}
930 once, just before you modify the text. You must supply the indices of
931 the text range that you are going to modify.
933 @deftypefun int rl_modifying (int start, int end)
934 Tell Readline to save the text between @var{start} and @var{end} as a
935 single undo unit. It is assumed that you will subsequently modify
940 @subsection Redisplay
942 @deftypefun void rl_redisplay (void)
943 Change what's displayed on the screen to reflect the current contents
944 of @code{rl_line_buffer}.
947 @deftypefun int rl_forced_update_display (void)
948 Force the line to be updated and redisplayed, whether or not
949 Readline thinks the screen display is correct.
952 @deftypefun int rl_on_new_line (void)
953 Tell the update functions that we have moved onto a new (empty) line,
954 usually after outputting a newline.
957 @deftypefun int rl_on_new_line_with_prompt (void)
958 Tell the update functions that we have moved onto a new line, with
959 @var{rl_prompt} already displayed.
960 This could be used by applications that want to output the prompt string
961 themselves, but still need Readline to know the prompt string length for
963 It should be used after setting @var{rl_already_prompted}.
966 @deftypefun int rl_clear_visible_line (void)
967 Clear the screen lines corresponding to the current line's contents.
970 @deftypefun int rl_reset_line_state (void)
971 Reset the display state to a clean state and redisplay the current line
972 starting on a new line.
975 @deftypefun int rl_crlf (void)
976 Move the cursor to the start of the next screen line.
979 @deftypefun int rl_show_char (int c)
980 Display character @var{c} on @code{rl_outstream}.
981 If Readline has not been set to display meta characters directly, this
982 will convert meta characters to a meta-prefixed key sequence.
983 This is intended for use by applications which wish to do their own
987 @deftypefun int rl_message (const char *, @dots{})
988 The arguments are a format string as would be supplied to @code{printf},
989 possibly containing conversion specifications such as @samp{%d}, and
990 any additional arguments necessary to satisfy the conversion specifications.
991 The resulting string is displayed in the @dfn{echo area}. The echo area
992 is also used to display numeric arguments and search strings.
993 You should call @code{rl_save_prompt} to save the prompt information
994 before calling this function.
997 @deftypefun int rl_clear_message (void)
998 Clear the message in the echo area. If the prompt was saved with a call to
999 @code{rl_save_prompt} before the last call to @code{rl_message},
1000 call @code{rl_restore_prompt} before calling this function.
1003 @deftypefun void rl_save_prompt (void)
1004 Save the local Readline prompt display state in preparation for
1005 displaying a new message in the message area with @code{rl_message()}.
1008 @deftypefun void rl_restore_prompt (void)
1009 Restore the local Readline prompt display state saved by the most
1010 recent call to @code{rl_save_prompt}.
1011 if @code{rl_save_prompt} was called to save the prompt before a call
1012 to @code{rl_message}, this function should be called before the
1013 corresponding call to @code{rl_clear_message}.
1016 @deftypefun int rl_expand_prompt (char *prompt)
1017 Expand any special character sequences in @var{prompt} and set up the
1018 local Readline prompt redisplay variables.
1019 This function is called by @code{readline()}. It may also be called to
1020 expand the primary prompt if the @code{rl_on_new_line_with_prompt()}
1021 function or @code{rl_already_prompted} variable is used.
1022 It returns the number of visible characters on the last line of the
1023 (possibly multi-line) prompt.
1024 Applications may indicate that the prompt contains characters that take
1025 up no physical screen space when displayed by bracketing a sequence of
1026 such characters with the special markers @code{RL_PROMPT_START_IGNORE}
1027 and @code{RL_PROMPT_END_IGNORE} (declared in @file{readline.h}). This may
1028 be used to embed terminal-specific escape sequences in prompts.
1031 @deftypefun int rl_set_prompt (const char *prompt)
1032 Make Readline use @var{prompt} for subsequent redisplay. This calls
1033 @code{rl_expand_prompt()} to expand the prompt and sets @code{rl_prompt}
1037 @node Modifying Text
1038 @subsection Modifying Text
1040 @deftypefun int rl_insert_text (const char *text)
1041 Insert @var{text} into the line at the current cursor position.
1042 Returns the number of characters inserted.
1045 @deftypefun int rl_delete_text (int start, int end)
1046 Delete the text between @var{start} and @var{end} in the current line.
1047 Returns the number of characters deleted.
1050 @deftypefun {char *} rl_copy_text (int start, int end)
1051 Return a copy of the text between @var{start} and @var{end} in
1055 @deftypefun int rl_kill_text (int start, int end)
1056 Copy the text between @var{start} and @var{end} in the current line
1057 to the kill ring, appending or prepending to the last kill if the
1058 last command was a kill command. The text is deleted.
1059 If @var{start} is less than @var{end},
1060 the text is appended, otherwise prepended. If the last command was
1061 not a kill, a new kill ring slot is used.
1064 @deftypefun int rl_push_macro_input (char *macro)
1065 Cause @var{macro} to be inserted into the line, as if it had been invoked
1066 by a key bound to a macro. Not especially useful; use
1067 @code{rl_insert_text()} instead.
1070 @node Character Input
1071 @subsection Character Input
1073 @deftypefun int rl_read_key (void)
1074 Return the next character available from Readline's current input stream.
1075 This handles input inserted into
1076 the input stream via @var{rl_pending_input} (@pxref{Readline Variables})
1077 and @code{rl_stuff_char()}, macros, and characters read from the keyboard.
1078 While waiting for input, this function will call any function assigned to
1079 the @code{rl_event_hook} variable.
1082 @deftypefun int rl_getc (FILE *stream)
1083 Return the next character available from @var{stream}, which is assumed to
1087 @deftypefun int rl_stuff_char (int c)
1088 Insert @var{c} into the Readline input stream. It will be "read"
1089 before Readline attempts to read characters from the terminal with
1090 @code{rl_read_key()}. Up to 512 characters may be pushed back.
1091 @code{rl_stuff_char} returns 1 if the character was successfully inserted;
1095 @deftypefun int rl_execute_next (int c)
1096 Make @var{c} be the next command to be executed when @code{rl_read_key()}
1097 is called. This sets @var{rl_pending_input}.
1100 @deftypefun int rl_clear_pending_input (void)
1101 Unset @var{rl_pending_input}, effectively negating the effect of any
1102 previous call to @code{rl_execute_next()}. This works only if the
1103 pending input has not already been read with @code{rl_read_key()}.
1106 @deftypefun int rl_set_keyboard_input_timeout (int u)
1107 While waiting for keyboard input in @code{rl_read_key()}, Readline will
1108 wait for @var{u} microseconds for input before calling any function
1109 assigned to @code{rl_event_hook}. @var{u} must be greater than or equal
1110 to zero (a zero-length timeout is equivalent to a poll).
1111 The default waiting period is one-tenth of a second.
1112 Returns the old timeout value.
1115 @node Terminal Management
1116 @subsection Terminal Management
1118 @deftypefun void rl_prep_terminal (int meta_flag)
1119 Modify the terminal settings for Readline's use, so @code{readline()}
1120 can read a single character at a time from the keyboard.
1121 The @var{meta_flag} argument should be non-zero if Readline should
1122 read eight-bit input.
1125 @deftypefun void rl_deprep_terminal (void)
1126 Undo the effects of @code{rl_prep_terminal()}, leaving the terminal in
1127 the state in which it was before the most recent call to
1128 @code{rl_prep_terminal()}.
1131 @deftypefun void rl_tty_set_default_bindings (Keymap kmap)
1132 Read the operating system's terminal editing characters (as would be
1133 displayed by @code{stty}) to their Readline equivalents.
1134 The bindings are performed in @var{kmap}.
1137 @deftypefun void rl_tty_unset_default_bindings (Keymap kmap)
1138 Reset the bindings manipulated by @code{rl_tty_set_default_bindings} so
1139 that the terminal editing characters are bound to @code{rl_insert}.
1140 The bindings are performed in @var{kmap}.
1143 @deftypefun int rl_tty_set_echoing (int value)
1144 Set Readline's idea of whether or not it is echoing output to its output
1145 stream (@var{rl_outstream}). If @var{value} is 0, Readline does not display
1146 output to @var{rl_outstream}; any other value enables output. The initial
1147 value is set when Readline initializes the terminal settings.
1148 This function returns the previous value.
1151 @deftypefun int rl_reset_terminal (const char *terminal_name)
1152 Reinitialize Readline's idea of the terminal settings using
1153 @var{terminal_name} as the terminal type (e.g., @code{vt100}).
1154 If @var{terminal_name} is @code{NULL}, the value of the @code{TERM}
1155 environment variable is used.
1158 @node Utility Functions
1159 @subsection Utility Functions
1161 @deftypefun int rl_save_state (struct readline_state *sp)
1162 Save a snapshot of Readline's internal state to @var{sp}.
1163 The contents of the @var{readline_state} structure are documented
1164 in @file{readline.h}.
1165 The caller is responsible for allocating the structure.
1168 @deftypefun int rl_restore_state (struct readline_state *sp)
1169 Restore Readline's internal state to that stored in @var{sp}, which must
1170 have been saved by a call to @code{rl_save_state}.
1171 The contents of the @var{readline_state} structure are documented
1172 in @file{readline.h}.
1173 The caller is responsible for freeing the structure.
1176 @deftypefun void rl_free (void *mem)
1177 Deallocate the memory pointed to by @var{mem}. @var{mem} must have been
1178 allocated by @code{malloc}.
1181 @deftypefun void rl_replace_line (const char *text, int clear_undo)
1182 Replace the contents of @code{rl_line_buffer} with @var{text}.
1183 The point and mark are preserved, if possible.
1184 If @var{clear_undo} is non-zero, the undo list associated with the
1185 current line is cleared.
1188 @deftypefun void rl_extend_line_buffer (int len)
1189 Ensure that @code{rl_line_buffer} has enough space to hold @var{len}
1190 characters, possibly reallocating it if necessary.
1193 @deftypefun int rl_initialize (void)
1194 Initialize or re-initialize Readline's internal state.
1195 It's not strictly necessary to call this; @code{readline()} calls it before
1199 @deftypefun int rl_ding (void)
1200 Ring the terminal bell, obeying the setting of @code{bell-style}.
1203 @deftypefun int rl_alphabetic (int c)
1204 Return 1 if @var{c} is an alphabetic character.
1207 @deftypefun void rl_display_match_list (char **matches, int len, int max)
1208 A convenience function for displaying a list of strings in
1209 columnar format on Readline's output stream. @code{matches} is the list
1210 of strings, in argv format, such as a list of completion matches.
1211 @code{len} is the number of strings in @code{matches}, and @code{max}
1212 is the length of the longest string in @code{matches}. This function uses
1213 the setting of @code{print-completions-horizontally} to select how the
1214 matches are displayed (@pxref{Readline Init File Syntax}).
1215 When displaying completions, this function sets the number of columns used
1216 for display to the value of @code{completion-display-width}, the value of
1217 the environment variable @env{COLUMNS}, or the screen width, in that order.
1220 The following are implemented as macros, defined in @code{chardefs.h}.
1221 Applications should refrain from using them.
1223 @deftypefun int _rl_uppercase_p (int c)
1224 Return 1 if @var{c} is an uppercase alphabetic character.
1227 @deftypefun int _rl_lowercase_p (int c)
1228 Return 1 if @var{c} is a lowercase alphabetic character.
1231 @deftypefun int _rl_digit_p (int c)
1232 Return 1 if @var{c} is a numeric character.
1235 @deftypefun int _rl_to_upper (int c)
1236 If @var{c} is a lowercase alphabetic character, return the corresponding
1237 uppercase character.
1240 @deftypefun int _rl_to_lower (int c)
1241 If @var{c} is an uppercase alphabetic character, return the corresponding
1242 lowercase character.
1245 @deftypefun int _rl_digit_value (int c)
1246 If @var{c} is a number, return the value it represents.
1249 @node Miscellaneous Functions
1250 @subsection Miscellaneous Functions
1252 @deftypefun int rl_macro_bind (const char *keyseq, const char *macro, Keymap map)
1253 Bind the key sequence @var{keyseq} to invoke the macro @var{macro}.
1254 The binding is performed in @var{map}. When @var{keyseq} is invoked, the
1255 @var{macro} will be inserted into the line. This function is deprecated;
1256 use @code{rl_generic_bind()} instead.
1259 @deftypefun void rl_macro_dumper (int readable)
1260 Print the key sequences bound to macros and their values, using
1261 the current keymap, to @code{rl_outstream}.
1262 If @var{readable} is non-zero, the list is formatted in such a way
1263 that it can be made part of an @code{inputrc} file and re-read.
1266 @deftypefun int rl_variable_bind (const char *variable, const char *value)
1267 Make the Readline variable @var{variable} have @var{value}.
1268 This behaves as if the readline command
1269 @samp{set @var{variable} @var{value}} had been executed in an @code{inputrc}
1270 file (@pxref{Readline Init File Syntax}).
1273 @deftypefun {char *} rl_variable_value (const char *variable)
1274 Return a string representing the value of the Readline variable @var{variable}.
1275 For boolean variables, this string is either @samp{on} or @samp{off}.
1278 @deftypefun void rl_variable_dumper (int readable)
1279 Print the readline variable names and their current values
1280 to @code{rl_outstream}.
1281 If @var{readable} is non-zero, the list is formatted in such a way
1282 that it can be made part of an @code{inputrc} file and re-read.
1285 @deftypefun int rl_set_paren_blink_timeout (int u)
1286 Set the time interval (in microseconds) that Readline waits when showing
1287 a balancing character when @code{blink-matching-paren} has been enabled.
1290 @deftypefun {char *} rl_get_termcap (const char *cap)
1291 Retrieve the string value of the termcap capability @var{cap}.
1292 Readline fetches the termcap entry for the current terminal name and
1293 uses those capabilities to move around the screen line and perform other
1294 terminal-specific operations, like erasing a line. Readline does not
1295 use all of a terminal's capabilities, and this function will return
1296 values for only those capabilities Readline uses.
1299 @deftypefun {void} rl_clear_history (void)
1300 Clear the history list by deleting all of the entries, in the same manner
1301 as the History library's @code{clear_history()} function.
1302 This differs from @code{clear_history} because it frees private data
1303 Readline saves in the history list.
1306 @node Alternate Interface
1307 @subsection Alternate Interface
1309 An alternate interface is available to plain @code{readline()}. Some
1310 applications need to interleave keyboard I/O with file, device, or
1311 window system I/O, typically by using a main loop to @code{select()}
1312 on various file descriptors. To accommodate this need, readline can
1313 also be invoked as a `callback' function from an event loop. There
1314 are functions available to make this easy.
1316 @deftypefun void rl_callback_handler_install (const char *prompt, rl_vcpfunc_t *lhandler)
1317 Set up the terminal for readline I/O and display the initial
1318 expanded value of @var{prompt}. Save the value of @var{lhandler} to
1319 use as a handler function to call when a complete line of input has been
1321 The handler function receives the text of the line as an argument.
1322 As with @code{readline()}, the handler function should @code{free} the
1323 line when it it finished with it.
1326 @deftypefun void rl_callback_read_char (void)
1327 Whenever an application determines that keyboard input is available, it
1328 should call @code{rl_callback_read_char()}, which will read the next
1329 character from the current input source.
1330 If that character completes the line, @code{rl_callback_read_char} will
1331 invoke the @var{lhandler} function installed by
1332 @code{rl_callback_handler_install} to process the line.
1333 Before calling the @var{lhandler} function, the terminal settings are
1334 reset to the values they had before calling
1335 @code{rl_callback_handler_install}.
1336 If the @var{lhandler} function returns,
1337 and the line handler remains installed,
1338 the terminal settings are modified for Readline's use again.
1339 @code{EOF} is indicated by calling @var{lhandler} with a
1343 @deftypefun void rl_callback_sigcleanup (void)
1344 Clean up any internal state the callback interface uses to maintain state
1345 between calls to rl_callback_read_char (e.g., the state of any active
1346 incremental searches). This is intended to be used by applications that
1347 wish to perform their own signal handling; Readline's internal signal handler
1348 calls this when appropriate.
1351 @deftypefun void rl_callback_handler_remove (void)
1352 Restore the terminal to its initial state and remove the line handler.
1353 You may call this function from within a callback as well as independently.
1354 If the @var{lhandler} installed by @code{rl_callback_handler_install}
1355 does not exit the program, either this function or the function referred
1356 to by the value of @code{rl_deprep_term_function} should be called before
1357 the program exits to reset the terminal settings.
1360 @node A Readline Example
1361 @subsection A Readline Example
1363 Here is a function which changes lowercase characters to their uppercase
1364 equivalents, and uppercase characters to lowercase. If
1365 this function was bound to @samp{M-c}, then typing @samp{M-c} would
1366 change the case of the character under point. Typing @samp{M-1 0 M-c}
1367 would change the case of the following 10 characters, leaving the cursor on
1368 the last character changed.
1371 /* Invert the case of the COUNT following characters. */
1373 invert_case_line (count, key)
1376 register int start, end, i;
1380 if (rl_point >= rl_end)
1391 /* Find the end of the range to modify. */
1392 end = start + (count * direction);
1394 /* Force it to be within range. */
1410 /* Tell readline that we are modifying the line,
1411 so it will save the undo information. */
1412 rl_modifying (start, end);
1414 for (i = start; i != end; i++)
1416 if (_rl_uppercase_p (rl_line_buffer[i]))
1417 rl_line_buffer[i] = _rl_to_lower (rl_line_buffer[i]);
1418 else if (_rl_lowercase_p (rl_line_buffer[i]))
1419 rl_line_buffer[i] = _rl_to_upper (rl_line_buffer[i]);
1421 /* Move point to on top of the last character changed. */
1422 rl_point = (direction == 1) ? end - 1 : start;
1427 @node Alternate Interface Example
1428 @subsection Alternate Interface Example
1430 Here is a complete program that illustrates Readline's alternate interface.
1431 It reads lines from the terminal and displays them, providing the
1432 standard history and TAB completion functions.
1433 It understands the EOF character or "exit" to exit the program.
1436 /* Standard include files. stdio.h is required. */
1442 /* Used for select(2) */
1443 #include <sys/types.h>
1444 #include <sys/select.h>
1450 /* Standard readline include files. */
1451 #include <readline/readline.h>
1452 #include <readline/history.h>
1454 static void cb_linehandler (char *);
1455 static void sighandler (int);
1458 int sigwinch_received;
1459 const char *prompt = "rltest$ ";
1461 /* Handle SIGWINCH and window size changes when readline is not active and
1462 reading a character. */
1464 sighandler (int sig)
1466 sigwinch_received = 1;
1469 /* Callback function called for each line when accept-line executed, EOF
1470 seen, or EOF character read. This sets a flag and returns; it could
1471 also call exit(3). */
1473 cb_linehandler (char *line)
1475 /* Can use ^D (stty eof) or `exit' to exit. */
1476 if (line == NULL || strcmp (line, "exit") == 0)
1481 /* This function needs to be called to reset the terminal settings,
1482 and calling it from the line handler keeps one extra prompt from
1484 rl_callback_handler_remove ();
1492 printf ("input line: %s\n", line);
1498 main (int c, char **v)
1503 /* Set the default locale values according to environment variables. */
1504 setlocale (LC_ALL, "");
1506 /* Handle window size changes when readline is not active and reading
1508 signal (SIGWINCH, sighandler);
1510 /* Install the line handler. */
1511 rl_callback_handler_install (prompt, cb_linehandler);
1513 /* Enter a simple event loop. This waits until something is available
1514 to read on readline's input stream (defaults to standard input) and
1515 calls the builtin character read callback to read it. It does not
1516 have to modify the user's terminal settings. */
1521 FD_SET (fileno (rl_instream), &fds);
1523 r = select (FD_SETSIZE, &fds, NULL, NULL, NULL);
1524 if (r < 0 && errno != EINTR)
1526 perror ("rltest: select");
1527 rl_callback_handler_remove ();
1530 if (sigwinch_received)
1532 rl_resize_terminal ();
1533 sigwinch_received = 0;
1538 if (FD_ISSET (fileno (rl_instream), &fds))
1539 rl_callback_read_char ();
1542 printf ("rltest: Event loop has exited\n");
1547 @node Readline Signal Handling
1548 @section Readline Signal Handling
1550 Signals are asynchronous events sent to a process by the Unix kernel,
1551 sometimes on behalf of another process. They are intended to indicate
1552 exceptional events, like a user pressing the interrupt key on his terminal,
1553 or a network connection being broken. There is a class of signals that can
1554 be sent to the process currently reading input from the keyboard. Since
1555 Readline changes the terminal attributes when it is called, it needs to
1556 perform special processing when such a signal is received in order to
1557 restore the terminal to a sane state, or provide application writers with
1558 functions to do so manually.
1560 Readline contains an internal signal handler that is installed for a
1561 number of signals (@code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM},
1563 @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}).
1564 When one of these signals is received, the signal handler
1565 will reset the terminal attributes to those that were in effect before
1566 @code{readline()} was called, reset the signal handling to what it was
1567 before @code{readline()} was called, and resend the signal to the calling
1569 If and when the calling application's signal handler returns, Readline
1570 will reinitialize the terminal and continue to accept input.
1571 When a @code{SIGINT} is received, the Readline signal handler performs
1572 some additional work, which will cause any partially-entered line to be
1573 aborted (see the description of @code{rl_free_line_state()} below).
1575 There is an additional Readline signal handler, for @code{SIGWINCH}, which
1576 the kernel sends to a process whenever the terminal's size changes (for
1577 example, if a user resizes an @code{xterm}). The Readline @code{SIGWINCH}
1578 handler updates Readline's internal screen size information, and then calls
1579 any @code{SIGWINCH} signal handler the calling application has installed.
1580 Readline calls the application's @code{SIGWINCH} signal handler without
1581 resetting the terminal to its original state. If the application's signal
1582 handler does more than update its idea of the terminal size and return (for
1583 example, a @code{longjmp} back to a main processing loop), it @emph{must}
1584 call @code{rl_cleanup_after_signal()} (described below), to restore the
1587 When an application is using the callback interface
1588 (@pxref{Alternate Interface}), Readline installs signal handlers only for
1589 the duration of the call to @code{rl_callback_read_char}. Applications
1590 using the callback interface should be prepared to clean up Readline's
1591 state if they wish to handle the signal before the line handler completes
1592 and restores the terminal state.
1594 If an application using the callback interface wishes to have Readline
1595 install its signal handlers at the time the application calls
1596 @code{rl_callback_handler_install} and remove them only when a complete
1597 line of input has been read, it should set the
1598 @code{rl_persistent_signal_handlers} variable to a non-zero value.
1599 This allows an application to defer all of the handling of the signals
1600 Readline catches to Readline.
1601 Applications should use this variable with care; it can result in Readline
1602 catching signals and not acting on them (or allowing the application to react
1603 to them) until the application calls @code{rl_callback_read_char}. This
1604 can result in an application becoming less responsive to keyboard signals
1606 If an application does not want or need to perform any signal handling, or
1607 does not need to do any processing between calls to @code{rl_callback_read_char},
1608 setting this variable may be desirable.
1610 Readline provides two variables that allow application writers to
1611 control whether or not it will catch certain signals and act on them
1612 when they are received. It is important that applications change the
1613 values of these variables only when calling @code{readline()}, not in
1614 a signal handler, so Readline's internal signal state is not corrupted.
1616 @deftypevar int rl_catch_signals
1617 If this variable is non-zero, Readline will install signal handlers for
1618 @code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, @code{SIGHUP}, @code{SIGALRM},
1619 @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}.
1621 The default value of @code{rl_catch_signals} is 1.
1624 @deftypevar int rl_catch_sigwinch
1625 If this variable is set to a non-zero value,
1626 Readline will install a signal handler for @code{SIGWINCH}.
1628 The default value of @code{rl_catch_sigwinch} is 1.
1631 @deftypevar int rl_persistent_signal_handlers
1632 If an application using the callback interface wishes Readline's signal
1633 handlers to be installed and active during the set of calls to
1634 @code{rl_callback_read_char} that constitutes an entire single line,
1635 it should set this variable to a non-zero value.
1637 The default value of @code{rl_persistent_signal_handlers} is 0.
1640 @deftypevar int rl_change_environment
1641 If this variable is set to a non-zero value,
1642 and Readline is handling @code{SIGWINCH}, Readline will modify the
1643 @var{LINES} and @var{COLUMNS} environment variables upon receipt of a
1646 The default value of @code{rl_change_environment} is 1.
1649 If an application does not wish to have Readline catch any signals, or
1650 to handle signals other than those Readline catches (@code{SIGHUP},
1652 Readline provides convenience functions to do the necessary terminal
1653 and internal state cleanup upon receipt of a signal.
1655 @deftypefun int rl_pending_signal (void)
1656 Return the signal number of the most recent signal Readline received but
1657 has not yet handled, or 0 if there is no pending signal.
1660 @deftypefun void rl_cleanup_after_signal (void)
1661 This function will reset the state of the terminal to what it was before
1662 @code{readline()} was called, and remove the Readline signal handlers for
1663 all signals, depending on the values of @code{rl_catch_signals} and
1664 @code{rl_catch_sigwinch}.
1667 @deftypefun void rl_free_line_state (void)
1668 This will free any partial state associated with the current input line
1669 (undo information, any partial history entry, any partially-entered
1670 keyboard macro, and any partially-entered numeric argument). This
1671 should be called before @code{rl_cleanup_after_signal()}. The
1672 Readline signal handler for @code{SIGINT} calls this to abort the
1676 @deftypefun void rl_reset_after_signal (void)
1677 This will reinitialize the terminal and reinstall any Readline signal
1678 handlers, depending on the values of @code{rl_catch_signals} and
1679 @code{rl_catch_sigwinch}.
1682 If an application does not wish Readline to catch @code{SIGWINCH}, it may
1683 call @code{rl_resize_terminal()} or @code{rl_set_screen_size()} to force
1684 Readline to update its idea of the terminal size when a @code{SIGWINCH}
1687 @deftypefun void rl_echo_signal_char (int sig)
1688 If an application wishes to install its own signal handlers, but still
1689 have readline display characters that generate signals, calling this
1690 function with @var{sig} set to @code{SIGINT}, @code{SIGQUIT}, or
1691 @code{SIGTSTP} will display the character generating that signal.
1694 @deftypefun void rl_resize_terminal (void)
1695 Update Readline's internal screen size by reading values from the kernel.
1698 @deftypefun void rl_set_screen_size (int rows, int cols)
1699 Set Readline's idea of the terminal size to @var{rows} rows and
1700 @var{cols} columns. If either @var{rows} or @var{columns} is less than
1701 or equal to 0, Readline's idea of that terminal dimension is unchanged.
1704 If an application does not want to install a @code{SIGWINCH} handler, but
1705 is still interested in the screen dimensions, Readline's idea of the screen
1706 size may be queried.
1708 @deftypefun void rl_get_screen_size (int *rows, int *cols)
1709 Return Readline's idea of the terminal's size in the
1710 variables pointed to by the arguments.
1713 @deftypefun void rl_reset_screen_size (void)
1714 Cause Readline to reobtain the screen size and recalculate its dimensions.
1717 The following functions install and remove Readline's signal handlers.
1719 @deftypefun int rl_set_signals (void)
1720 Install Readline's signal handler for @code{SIGINT}, @code{SIGQUIT},
1721 @code{SIGTERM}, @code{SIGHUP}, @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN},
1722 @code{SIGTTOU}, and @code{SIGWINCH}, depending on the values of
1723 @code{rl_catch_signals} and @code{rl_catch_sigwinch}.
1726 @deftypefun int rl_clear_signals (void)
1727 Remove all of the Readline signal handlers installed by
1728 @code{rl_set_signals()}.
1731 @node Custom Completers
1732 @section Custom Completers
1733 @cindex application-specific completion functions
1735 Typically, a program that reads commands from the user has a way of
1736 disambiguating commands and data. If your program is one of these, then
1737 it can provide completion for commands, data, or both.
1738 The following sections describe how your program and Readline
1739 cooperate to provide this service.
1742 * How Completing Works:: The logic used to do completion.
1743 * Completion Functions:: Functions provided by Readline.
1744 * Completion Variables:: Variables which control completion.
1745 * A Short Completion Example:: An example of writing completer subroutines.
1748 @node How Completing Works
1749 @subsection How Completing Works
1751 In order to complete some text, the full list of possible completions
1752 must be available. That is, it is not possible to accurately
1753 expand a partial word without knowing all of the possible words
1754 which make sense in that context. The Readline library provides
1755 the user interface to completion, and two of the most common
1756 completion functions: filename and username. For completing other types
1757 of text, you must write your own completion function. This section
1758 describes exactly what such functions must do, and provides an example.
1760 There are three major functions used to perform completion:
1764 The user-interface function @code{rl_complete()}. This function is
1765 called with the same arguments as other bindable Readline functions:
1766 @var{count} and @var{invoking_key}.
1767 It isolates the word to be completed and calls
1768 @code{rl_completion_matches()} to generate a list of possible completions.
1769 It then either lists the possible completions, inserts the possible
1770 completions, or actually performs the
1771 completion, depending on which behavior is desired.
1774 The internal function @code{rl_completion_matches()} uses an
1775 application-supplied @dfn{generator} function to generate the list of
1776 possible matches, and then returns the array of these matches.
1777 The caller should place the address of its generator function in
1778 @code{rl_completion_entry_function}.
1781 The generator function is called repeatedly from
1782 @code{rl_completion_matches()}, returning a string each time. The
1783 arguments to the generator function are @var{text} and @var{state}.
1784 @var{text} is the partial word to be completed. @var{state} is zero the
1785 first time the function is called, allowing the generator to perform
1786 any necessary initialization, and a positive non-zero integer for
1787 each subsequent call. The generator function returns
1788 @code{(char *)NULL} to inform @code{rl_completion_matches()} that there are
1789 no more possibilities left. Usually the generator function computes the
1790 list of possible completions when @var{state} is zero, and returns them
1791 one at a time on subsequent calls. Each string the generator function
1792 returns as a match must be allocated with @code{malloc()}; Readline
1793 frees the strings when it has finished with them.
1794 Such a generator function is referred to as an
1795 @dfn{application-specific completion function}.
1799 @deftypefun int rl_complete (int ignore, int invoking_key)
1800 Complete the word at or before point. You have supplied the function
1801 that does the initial simple matching selection algorithm (see
1802 @code{rl_completion_matches()}). The default is to do filename completion.
1805 @deftypevar {rl_compentry_func_t *} rl_completion_entry_function
1806 This is a pointer to the generator function for
1807 @code{rl_completion_matches()}.
1808 If the value of @code{rl_completion_entry_function} is
1809 @code{NULL} then the default filename generator
1810 function, @code{rl_filename_completion_function()}, is used.
1811 An @dfn{application-specific completion function} is a function whose
1812 address is assigned to @code{rl_completion_entry_function} and whose
1813 return values are used to generate possible completions.
1816 @node Completion Functions
1817 @subsection Completion Functions
1819 Here is the complete list of callable completion functions present in
1822 @deftypefun int rl_complete_internal (int what_to_do)
1823 Complete the word at or before point. @var{what_to_do} says what to do
1824 with the completion. A value of @samp{?} means list the possible
1825 completions. @samp{TAB} means do standard completion. @samp{*} means
1826 insert all of the possible completions. @samp{!} means to display
1827 all of the possible completions, if there is more than one, as well as
1828 performing partial completion. @samp{@@} is similar to @samp{!}, but
1829 possible completions are not listed if the possible completions share
1833 @deftypefun int rl_complete (int ignore, int invoking_key)
1834 Complete the word at or before point. You have supplied the function
1835 that does the initial simple matching selection algorithm (see
1836 @code{rl_completion_matches()} and @code{rl_completion_entry_function}).
1837 The default is to do filename
1838 completion. This calls @code{rl_complete_internal()} with an
1839 argument depending on @var{invoking_key}.
1842 @deftypefun int rl_possible_completions (int count, int invoking_key)
1843 List the possible completions. See description of @code{rl_complete
1844 ()}. This calls @code{rl_complete_internal()} with an argument of
1848 @deftypefun int rl_insert_completions (int count, int invoking_key)
1849 Insert the list of possible completions into the line, deleting the
1850 partially-completed word. See description of @code{rl_complete()}.
1851 This calls @code{rl_complete_internal()} with an argument of @samp{*}.
1854 @deftypefun int rl_completion_mode (rl_command_func_t *cfunc)
1855 Returns the appropriate value to pass to @code{rl_complete_internal()}
1856 depending on whether @var{cfunc} was called twice in succession and
1857 the values of the @code{show-all-if-ambiguous} and
1858 @code{show-all-if-unmodified} variables.
1859 Application-specific completion functions may use this function to present
1860 the same interface as @code{rl_complete()}.
1863 @deftypefun {char **} rl_completion_matches (const char *text, rl_compentry_func_t *entry_func)
1864 Returns an array of strings which is a list of completions for
1865 @var{text}. If there are no completions, returns @code{NULL}.
1866 The first entry in the returned array is the substitution for @var{text}.
1867 The remaining entries are the possible completions. The array is
1868 terminated with a @code{NULL} pointer.
1870 @var{entry_func} is a function of two args, and returns a
1871 @code{char *}. The first argument is @var{text}. The second is a
1872 state argument; it is zero on the first call, and non-zero on subsequent
1873 calls. @var{entry_func} returns a @code{NULL} pointer to the caller
1874 when there are no more matches.
1877 @deftypefun {char *} rl_filename_completion_function (const char *text, int state)
1878 A generator function for filename completion in the general case.
1879 @var{text} is a partial filename.
1880 The Bash source is a useful reference for writing application-specific
1881 completion functions (the Bash completion functions call this and other
1882 Readline functions).
1885 @deftypefun {char *} rl_username_completion_function (const char *text, int state)
1886 A completion generator for usernames. @var{text} contains a partial
1887 username preceded by a random character (usually @samp{~}). As with all
1888 completion generators, @var{state} is zero on the first call and non-zero
1889 for subsequent calls.
1892 @node Completion Variables
1893 @subsection Completion Variables
1895 @deftypevar {rl_compentry_func_t *} rl_completion_entry_function
1896 A pointer to the generator function for @code{rl_completion_matches()}.
1897 @code{NULL} means to use @code{rl_filename_completion_function()},
1898 the default filename completer.
1901 @deftypevar {rl_completion_func_t *} rl_attempted_completion_function
1902 A pointer to an alternative function to create matches.
1903 The function is called with @var{text}, @var{start}, and @var{end}.
1904 @var{start} and @var{end} are indices in @code{rl_line_buffer} defining
1905 the boundaries of @var{text}, which is a character string.
1906 If this function exists and returns @code{NULL}, or if this variable is
1907 set to @code{NULL}, then @code{rl_complete()} will call the value of
1908 @code{rl_completion_entry_function} to generate matches, otherwise the
1909 array of strings returned will be used.
1910 If this function sets the @code{rl_attempted_completion_over}
1911 variable to a non-zero value, Readline will not perform its default
1912 completion even if this function returns no matches.
1915 @deftypevar {rl_quote_func_t *} rl_filename_quoting_function
1916 A pointer to a function that will quote a filename in an
1917 application-specific fashion. This is called if filename completion is being
1918 attempted and one of the characters in @code{rl_filename_quote_characters}
1919 appears in a completed filename. The function is called with
1920 @var{text}, @var{match_type}, and @var{quote_pointer}. The @var{text}
1921 is the filename to be quoted. The @var{match_type} is either
1922 @code{SINGLE_MATCH}, if there is only one completion match, or
1923 @code{MULT_MATCH}. Some functions use this to decide whether or not to
1924 insert a closing quote character. The @var{quote_pointer} is a pointer
1925 to any opening quote character the user typed. Some functions choose
1926 to reset this character.
1929 @deftypevar {rl_dequote_func_t *} rl_filename_dequoting_function
1930 A pointer to a function that will remove application-specific quoting
1931 characters from a filename before completion is attempted, so those
1932 characters do not interfere with matching the text against names in
1933 the filesystem. It is called with @var{text}, the text of the word
1934 to be dequoted, and @var{quote_char}, which is the quoting character
1935 that delimits the filename (usually @samp{'} or @samp{"}). If
1936 @var{quote_char} is zero, the filename was not in an embedded string.
1939 @deftypevar {rl_linebuf_func_t *} rl_char_is_quoted_p
1940 A pointer to a function to call that determines whether or not a specific
1941 character in the line buffer is quoted, according to whatever quoting
1942 mechanism the program calling Readline uses. The function is called with
1943 two arguments: @var{text}, the text of the line, and @var{index}, the
1944 index of the character in the line. It is used to decide whether a
1945 character found in @code{rl_completer_word_break_characters} should be
1946 used to break words for the completer.
1949 @deftypevar {rl_compignore_func_t *} rl_ignore_some_completions_function
1950 This function, if defined, is called by the completer when real filename
1951 completion is done, after all the matching names have been generated.
1952 It is passed a @code{NULL} terminated array of matches.
1953 The first element (@code{matches[0]}) is the
1954 maximal substring common to all matches. This function can
1955 re-arrange the list of matches as required, but each element deleted
1956 from the array must be freed.
1959 @deftypevar {rl_icppfunc_t *} rl_directory_completion_hook
1960 This function, if defined, is allowed to modify the directory portion
1961 of filenames Readline completes.
1962 It could be used to expand symbolic links or shell variables in pathnames.
1963 It is called with the address of a string (the current directory name) as an
1964 argument, and may modify that string.
1965 If the string is replaced with a new string, the old value should be freed.
1966 Any modified directory name should have a trailing slash.
1967 The modified value will be used as part of the completion, replacing
1968 the directory portion of the pathname the user typed.
1969 At the least, even if no other expansion is performed, this function should
1970 remove any quote characters from the directory name, because its result will
1971 be passed directly to @code{opendir()}.
1973 The directory completion hook returns an integer that should be non-zero if
1974 the function modifies its directory argument.
1975 The function should not modify the directory argument if it returns 0.
1978 @deftypevar {rl_icppfunc_t *} rl_directory_rewrite_hook;
1979 If non-zero, this is the address of a function to call when completing
1980 a directory name. This function takes the address of the directory name
1981 to be modified as an argument. Unlike @code{rl_directory_completion_hook},
1982 it only modifies the directory name used in @code{opendir}, not what is
1983 displayed when the possible completions are printed or inserted. It is
1984 called before rl_directory_completion_hook.
1985 At the least, even if no other expansion is performed, this function should
1986 remove any quote characters from the directory name, because its result will
1987 be passed directly to @code{opendir()}.
1989 The directory rewrite hook returns an integer that should be non-zero if
1990 the function modfies its directory argument.
1991 The function should not modify the directory argument if it returns 0.
1994 @deftypevar {rl_icppfunc_t *} rl_filename_stat_hook
1995 If non-zero, this is the address of a function for the completer to
1996 call before deciding which character to append to a completed name.
1997 This function modifies its filename name argument, and the modified value
1998 is passed to @code{stat()} to determine the file's type and characteristics.
1999 This function does not need to remove quote characters from the filename.
2001 The stat hook returns an integer that should be non-zero if
2002 the function modfies its directory argument.
2003 The function should not modify the directory argument if it returns 0.
2006 @deftypevar {rl_dequote_func_t *} rl_filename_rewrite_hook
2007 If non-zero, this is the address of a function called when reading
2008 directory entries from the filesystem for completion and comparing
2009 them to the partial word to be completed. The function should
2010 perform any necessary application or system-specific conversion on
2011 the filename, such as converting between character sets or converting
2012 from a filesystem format to a character input format.
2013 The function takes two arguments: @var{fname}, the filename to be converted,
2014 and @var{fnlen}, its length in bytes.
2015 It must either return its first argument (if no conversion takes place)
2016 or the converted filename in newly-allocated memory. The converted
2017 form is used to compare against the word to be completed, and, if it
2018 matches, is added to the list of matches. Readline will free the
2022 @deftypevar {rl_compdisp_func_t *} rl_completion_display_matches_hook
2023 If non-zero, then this is the address of a function to call when
2024 completing a word would normally display the list of possible matches.
2025 This function is called in lieu of Readline displaying the list.
2026 It takes three arguments:
2027 (@code{char **}@var{matches}, @code{int} @var{num_matches}, @code{int} @var{max_length})
2028 where @var{matches} is the array of matching strings,
2029 @var{num_matches} is the number of strings in that array, and
2030 @var{max_length} is the length of the longest string in that array.
2031 Readline provides a convenience function, @code{rl_display_match_list},
2032 that takes care of doing the display to Readline's output stream.
2033 You may call that function from this hook.
2036 @deftypevar {const char *} rl_basic_word_break_characters
2037 The basic list of characters that signal a break between words for the
2038 completer routine. The default value of this variable is the characters
2039 which break words for completion in Bash:
2040 @code{" \t\n\"\\'`@@$><=;|&@{("}.
2043 @deftypevar {const char *} rl_basic_quote_characters
2044 A list of quote characters which can cause a word break.
2047 @deftypevar {const char *} rl_completer_word_break_characters
2048 The list of characters that signal a break between words for
2049 @code{rl_complete_internal()}. The default list is the value of
2050 @code{rl_basic_word_break_characters}.
2053 @deftypevar {rl_cpvfunc_t *} rl_completion_word_break_hook
2054 If non-zero, this is the address of a function to call when Readline is
2055 deciding where to separate words for word completion. It should return
2056 a character string like @code{rl_completer_word_break_characters} to be
2057 used to perform the current completion. The function may choose to set
2058 @code{rl_completer_word_break_characters} itself. If the function
2059 returns @code{NULL}, @code{rl_completer_word_break_characters} is used.
2062 @deftypevar {const char *} rl_completer_quote_characters
2063 A list of characters which can be used to quote a substring of the line.
2064 Completion occurs on the entire substring, and within the substring
2065 @code{rl_completer_word_break_characters} are treated as any other character,
2066 unless they also appear within this list.
2069 @deftypevar {const char *} rl_filename_quote_characters
2070 A list of characters that cause a filename to be quoted by the completer
2071 when they appear in a completed filename. The default is the null string.
2074 @deftypevar {const char *} rl_special_prefixes
2075 The list of characters that are word break characters, but should be
2076 left in @var{text} when it is passed to the completion function.
2077 Programs can use this to help determine what kind of completing to do.
2078 For instance, Bash sets this variable to "$@@" so that it can complete
2079 shell variables and hostnames.
2082 @deftypevar int rl_completion_query_items
2083 Up to this many items will be displayed in response to a
2084 possible-completions call. After that, readline asks the user if she is sure
2085 she wants to see them all. The default value is 100. A negative value
2086 indicates that Readline should never ask the user.
2089 @deftypevar {int} rl_completion_append_character
2090 When a single completion alternative matches at the end of the command
2091 line, this character is appended to the inserted completion text. The
2092 default is a space character (@samp{ }). Setting this to the null
2093 character (@samp{\0}) prevents anything being appended automatically.
2094 This can be changed in application-specific completion functions to
2095 provide the ``most sensible word separator character'' according to
2096 an application-specific command line syntax specification.
2099 @deftypevar int rl_completion_suppress_append
2100 If non-zero, @var{rl_completion_append_character} is not appended to
2101 matches at the end of the command line, as described above.
2102 It is set to 0 before any application-specific completion function
2103 is called, and may only be changed within such a function.
2106 @deftypevar int rl_completion_quote_character
2107 When Readline is completing quoted text, as delimited by one of the
2108 characters in @var{rl_completer_quote_characters}, it sets this variable
2109 to the quoting character found.
2110 This is set before any application-specific completion function is called.
2113 @deftypevar int rl_completion_suppress_quote
2114 If non-zero, Readline does not append a matching quote character when
2115 performing completion on a quoted string.
2116 It is set to 0 before any application-specific completion function
2117 is called, and may only be changed within such a function.
2120 @deftypevar int rl_completion_found_quote
2121 When Readline is completing quoted text, it sets this variable
2122 to a non-zero value if the word being completed contains or is delimited
2123 by any quoting characters, including backslashes.
2124 This is set before any application-specific completion function is called.
2127 @deftypevar int rl_completion_mark_symlink_dirs
2128 If non-zero, a slash will be appended to completed filenames that are
2129 symbolic links to directory names, subject to the value of the
2130 user-settable @var{mark-directories} variable.
2131 This variable exists so that application-specific completion functions
2132 can override the user's global preference (set via the
2133 @var{mark-symlinked-directories} Readline variable) if appropriate.
2134 This variable is set to the user's preference before any
2135 application-specific completion function is called, so unless that
2136 function modifies the value, the user's preferences are honored.
2139 @deftypevar int rl_ignore_completion_duplicates
2140 If non-zero, then duplicates in the matches are removed.
2144 @deftypevar int rl_filename_completion_desired
2145 Non-zero means that the results of the matches are to be treated as
2146 filenames. This is @emph{always} zero when completion is attempted,
2147 and can only be changed
2148 within an application-specific completion function. If it is set to a
2149 non-zero value by such a function, directory names have a slash appended
2150 and Readline attempts to quote completed filenames if they contain any
2151 characters in @code{rl_filename_quote_characters} and
2152 @code{rl_filename_quoting_desired} is set to a non-zero value.
2155 @deftypevar int rl_filename_quoting_desired
2156 Non-zero means that the results of the matches are to be quoted using
2157 double quotes (or an application-specific quoting mechanism) if the
2158 completed filename contains any characters in
2159 @code{rl_filename_quote_chars}. This is @emph{always} non-zero
2160 when completion is attempted, and can only be changed within an
2161 application-specific completion function.
2162 The quoting is effected via a call to the function pointed to
2163 by @code{rl_filename_quoting_function}.
2166 @deftypevar int rl_attempted_completion_over
2167 If an application-specific completion function assigned to
2168 @code{rl_attempted_completion_function} sets this variable to a non-zero
2169 value, Readline will not perform its default filename completion even
2170 if the application's completion function returns no matches.
2171 It should be set only by an application's completion function.
2174 @deftypevar int rl_sort_completion_matches
2175 If an application sets this variable to 0, Readline will not sort the
2176 list of completions (which implies that it cannot remove any duplicate
2177 completions). The default value is 1, which means that Readline will
2178 sort the completions and, depending on the value of
2179 @code{rl_ignore_completion_duplicates}, will attempt to remove duplicate
2183 @deftypevar int rl_completion_type
2184 Set to a character describing the type of completion Readline is currently
2185 attempting; see the description of @code{rl_complete_internal()}
2186 (@pxref{Completion Functions}) for the list of characters.
2187 This is set to the appropriate value before any application-specific
2188 completion function is called, allowing such functions to present
2189 the same interface as @code{rl_complete()}.
2192 @deftypevar int rl_completion_invoking_key
2193 Set to the final character in the key sequence that invoked one of the
2194 completion functions that call @code{rl_complete_internal()}. This is
2195 set to the appropriate value before any application-specific completion
2199 @deftypevar int rl_inhibit_completion
2200 If this variable is non-zero, completion is inhibited. The completion
2201 character will be inserted as any other bound to @code{self-insert}.
2204 @node A Short Completion Example
2205 @subsection A Short Completion Example
2207 Here is a small application demonstrating the use of the GNU Readline
2208 library. It is called @code{fileman}, and the source code resides in
2209 @file{examples/fileman.c}. This sample application provides
2210 completion of command names, line editing features, and access to the
2215 /* fileman.c -- A tiny application which demonstrates how to use the
2216 GNU Readline library. This application interactively allows users
2217 to manipulate files and their modes. */
2219 #ifdef HAVE_CONFIG_H
2220 # include <config.h>
2223 #include <sys/types.h>
2224 #ifdef HAVE_SYS_FILE_H
2225 # include <sys/file.h>
2227 #include <sys/stat.h>
2229 #ifdef HAVE_UNISTD_H
2230 # include <unistd.h>
2237 #if defined (HAVE_STRING_H)
2238 # include <string.h>
2239 #else /* !HAVE_STRING_H */
2240 # include <strings.h>
2241 #endif /* !HAVE_STRING_H */
2243 #ifdef HAVE_STDLIB_H
2244 # include <stdlib.h>
2249 #include <readline/readline.h>
2250 #include <readline/history.h>
2252 extern char *xmalloc PARAMS((size_t));
2254 /* The names of functions that actually do the manipulation. */
2255 int com_list PARAMS((char *));
2256 int com_view PARAMS((char *));
2257 int com_rename PARAMS((char *));
2258 int com_stat PARAMS((char *));
2259 int com_pwd PARAMS((char *));
2260 int com_delete PARAMS((char *));
2261 int com_help PARAMS((char *));
2262 int com_cd PARAMS((char *));
2263 int com_quit PARAMS((char *));
2265 /* A structure which contains information on the commands this program
2269 char *name; /* User printable name of the function. */
2270 rl_icpfunc_t *func; /* Function to call to do the job. */
2271 char *doc; /* Documentation for this function. */
2274 COMMAND commands[] = @{
2275 @{ "cd", com_cd, "Change to directory DIR" @},
2276 @{ "delete", com_delete, "Delete FILE" @},
2277 @{ "help", com_help, "Display this text" @},
2278 @{ "?", com_help, "Synonym for `help'" @},
2279 @{ "list", com_list, "List files in DIR" @},
2280 @{ "ls", com_list, "Synonym for `list'" @},
2281 @{ "pwd", com_pwd, "Print the current working directory" @},
2282 @{ "quit", com_quit, "Quit using Fileman" @},
2283 @{ "rename", com_rename, "Rename FILE to NEWNAME" @},
2284 @{ "stat", com_stat, "Print out statistics on FILE" @},
2285 @{ "view", com_view, "View the contents of FILE" @},
2286 @{ (char *)NULL, (rl_icpfunc_t *)NULL, (char *)NULL @}
2289 /* Forward declarations. */
2290 char *stripwhite ();
2291 COMMAND *find_command ();
2293 /* The name of this program, as taken from argv[0]. */
2296 /* When non-zero, this global means the user is done using this program. */
2305 r = xmalloc (strlen (s) + 1);
2318 initialize_readline (); /* Bind our completer. */
2320 /* Loop reading and executing lines until the user quits. */
2321 for ( ; done == 0; )
2323 line = readline ("FileMan: ");
2328 /* Remove leading and trailing whitespace from the line.
2329 Then, if there is anything left, add it to the history list
2331 s = stripwhite (line);
2344 /* Execute a command line. */
2353 /* Isolate the command word. */
2355 while (line[i] && whitespace (line[i]))
2359 while (line[i] && !whitespace (line[i]))
2365 command = find_command (word);
2369 fprintf (stderr, "%s: No such command for FileMan.\n", word);
2373 /* Get argument to command, if any. */
2374 while (whitespace (line[i]))
2379 /* Call the function. */
2380 return ((*(command->func)) (word));
2383 /* Look up NAME as the name of a command, and return a pointer to that
2384 command. Return a NULL pointer if NAME isn't a command name. */
2391 for (i = 0; commands[i].name; i++)
2392 if (strcmp (name, commands[i].name) == 0)
2393 return (&commands[i]);
2395 return ((COMMAND *)NULL);
2398 /* Strip whitespace from the start and end of STRING. Return a pointer
2404 register char *s, *t;
2406 for (s = string; whitespace (*s); s++)
2412 t = s + strlen (s) - 1;
2413 while (t > s && whitespace (*t))
2420 /* **************************************************************** */
2422 /* Interface to Readline Completion */
2424 /* **************************************************************** */
2426 char *command_generator PARAMS((const char *, int));
2427 char **fileman_completion PARAMS((const char *, int, int));
2429 /* Tell the GNU Readline library how to complete. We want to try to complete
2430 on command names if this is the first word in the line, or on filenames
2432 initialize_readline ()
2434 /* Allow conditional parsing of the ~/.inputrc file. */
2435 rl_readline_name = "FileMan";
2437 /* Tell the completer that we want a crack first. */
2438 rl_attempted_completion_function = fileman_completion;
2441 /* Attempt to complete on the contents of TEXT. START and END bound the
2442 region of rl_line_buffer that contains the word to complete. TEXT is
2443 the word to complete. We can use the entire contents of rl_line_buffer
2444 in case we want to do some simple parsing. Return the array of matches,
2445 or NULL if there aren't any. */
2447 fileman_completion (text, start, end)
2453 matches = (char **)NULL;
2455 /* If this word is at the start of the line, then it is a command
2456 to complete. Otherwise it is the name of a file in the current
2459 matches = rl_completion_matches (text, command_generator);
2464 /* Generator function for command completion. STATE lets us know whether
2465 to start from scratch; without any state (i.e. STATE == 0), then we
2466 start at the top of the list. */
2468 command_generator (text, state)
2472 static int list_index, len;
2475 /* If this is a new word to complete, initialize now. This includes
2476 saving the length of TEXT for efficiency, and initializing the index
2481 len = strlen (text);
2484 /* Return the next name which partially matches from the command list. */
2485 while (name = commands[list_index].name)
2489 if (strncmp (name, text, len) == 0)
2490 return (dupstr(name));
2493 /* If no names matched, then return NULL. */
2494 return ((char *)NULL);
2497 /* **************************************************************** */
2499 /* FileMan Commands */
2501 /* **************************************************************** */
2503 /* String to pass to system (). This is for the LIST, VIEW and RENAME
2505 static char syscom[1024];
2507 /* List the file(s) named in arg. */
2514 sprintf (syscom, "ls -FClg %s", arg);
2515 return (system (syscom));
2521 if (!valid_argument ("view", arg))
2524 #if defined (__MSDOS__)
2525 /* more.com doesn't grok slashes in pathnames */
2526 sprintf (syscom, "less %s", arg);
2528 sprintf (syscom, "more %s", arg);
2530 return (system (syscom));
2536 too_dangerous ("rename");
2545 if (!valid_argument ("stat", arg))
2548 if (stat (arg, &finfo) == -1)
2554 printf ("Statistics for `%s':\n", arg);
2556 printf ("%s has %d link%s, and is %d byte%s in length.\n",
2559 (finfo.st_nlink == 1) ? "" : "s",
2561 (finfo.st_size == 1) ? "" : "s");
2562 printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime));
2563 printf (" Last access at: %s", ctime (&finfo.st_atime));
2564 printf (" Last modified at: %s", ctime (&finfo.st_mtime));
2571 too_dangerous ("delete");
2575 /* Print out help for ARG, or for all of the commands if ARG is
2583 for (i = 0; commands[i].name; i++)
2585 if (!*arg || (strcmp (arg, commands[i].name) == 0))
2587 printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc);
2594 printf ("No commands match `%s'. Possibilties are:\n", arg);
2596 for (i = 0; commands[i].name; i++)
2598 /* Print in six columns. */
2605 printf ("%s\t", commands[i].name);
2615 /* Change to the directory ARG. */
2619 if (chdir (arg) == -1)
2629 /* Print out the current working directory. */
2635 s = getcwd (dir, sizeof(dir) - 1);
2638 printf ("Error getting pwd: %s\n", dir);
2642 printf ("Current directory is %s\n", dir);
2646 /* The user wishes to quit using this program. Just set DONE non-zero. */
2654 /* Function which tells you that you can't do this. */
2655 too_dangerous (caller)
2659 "%s: Too dangerous for me to distribute. Write it yourself.\n",
2663 /* Return non-zero if ARG is a valid argument for CALLER, else print
2664 an error message and return zero. */
2666 valid_argument (caller, arg)
2671 fprintf (stderr, "%s: Argument required.\n", caller);