1 @comment %**start of header (This is for running Texinfo on a region.)
2 @setfilename rltech.info
3 @comment %**end of header (This is for running Texinfo on a region.)
7 This document describes the GNU Readline Library, a utility for aiding
8 in the consistency of user interface across discrete programs that need
9 to provide a command line interface.
11 Copyright (C) 1988-2005 Free Software Foundation, Inc.
13 Permission is granted to make and distribute verbatim copies of
14 this manual provided the copyright notice and this permission notice
15 pare preserved on all copies.
18 Permission is granted to process this file through TeX and print the
19 results, provided the printed document carries copying permission
20 notice identical to this one except for the removal of this paragraph
21 (this paragraph not being relevant to the printed manual).
24 Permission is granted to copy and distribute modified versions of this
25 manual under the conditions for verbatim copying, provided that the entire
26 resulting derived work is distributed under the terms of a permission
27 notice identical to this one.
29 Permission is granted to copy and distribute translations of this manual
30 into another language, under the above conditions for modified versions,
31 except that this permission notice may be stated in a translation approved
35 @node Programming with GNU Readline
36 @chapter Programming with GNU Readline
38 This chapter describes the interface between the @sc{gnu} Readline Library and
39 other programs. If you are a programmer, and you wish to include the
40 features found in @sc{gnu} Readline
41 such as completion, line editing, and interactive history manipulation
42 in your own programs, this section is for you.
45 * Basic Behavior:: Using the default behavior of Readline.
46 * Custom Functions:: Adding your own functions to Readline.
47 * Readline Variables:: Variables accessible to custom
49 * Readline Convenience Functions:: Functions which Readline supplies to
50 aid in writing your own custom
52 * Readline Signal Handling:: How Readline behaves when it receives signals.
53 * Custom Completers:: Supplanting or supplementing Readline's
58 @section Basic Behavior
60 Many programs provide a command line interface, such as @code{mail},
61 @code{ftp}, and @code{sh}. For such programs, the default behaviour of
62 Readline is sufficient. This section describes how to use Readline in
63 the simplest way possible, perhaps to replace calls in your code to
64 @code{gets()} or @code{fgets()}.
67 @cindex readline, function
69 The function @code{readline()} prints a prompt @var{prompt}
70 and then reads and returns a single line of text from the user.
71 If @var{prompt} is @code{NULL} or the empty string, no prompt is displayed.
72 The line @code{readline} returns is allocated with @code{malloc()};
73 the caller should @code{free()} the line when it has finished with it.
74 The declaration for @code{readline} in ANSI C is
77 @code{char *readline (const char *@var{prompt});}
83 @code{char *line = readline ("Enter a line: ");}
86 in order to read a line of text from the user.
87 The line returned has the final newline removed, so only the
90 If @code{readline} encounters an @code{EOF} while reading the line, and the
91 line is empty at that point, then @code{(char *)NULL} is returned.
92 Otherwise, the line is ended just as if a newline had been typed.
94 If you want the user to be able to get at the line later, (with
95 @key{C-p} for example), you must call @code{add_history()} to save the
96 line away in a @dfn{history} list of such lines.
99 @code{add_history (line)};
103 For full details on the GNU History Library, see the associated manual.
105 It is preferable to avoid saving empty lines on the history list, since
106 users rarely have a burning need to reuse a blank line. Here is
107 a function which usefully replaces the standard @code{gets()} library
108 function, and has the advantage of no static buffer to overflow:
111 /* A static variable for holding the line. */
112 static char *line_read = (char *)NULL;
114 /* Read a string, and return a pointer to it.
115 Returns NULL on EOF. */
119 /* If the buffer has already been allocated,
120 return the memory to the free pool. */
124 line_read = (char *)NULL;
127 /* Get a line from the user. */
128 line_read = readline ("");
130 /* If the line has any text in it,
131 save it on the history. */
132 if (line_read && *line_read)
133 add_history (line_read);
139 This function gives the user the default behaviour of @key{TAB}
140 completion: completion on file names. If you do not want Readline to
141 complete on filenames, you can change the binding of the @key{TAB} key
142 with @code{rl_bind_key()}.
145 @code{int rl_bind_key (int @var{key}, rl_command_func_t *@var{function});}
148 @code{rl_bind_key()} takes two arguments: @var{key} is the character that
149 you want to bind, and @var{function} is the address of the function to
150 call when @var{key} is pressed. Binding @key{TAB} to @code{rl_insert()}
151 makes @key{TAB} insert itself.
152 @code{rl_bind_key()} returns non-zero if @var{key} is not a valid
153 ASCII character code (between 0 and 255).
155 Thus, to disable the default @key{TAB} behavior, the following suffices:
157 @code{rl_bind_key ('\t', rl_insert);}
160 This code should be executed once at the start of your program; you
161 might write a function called @code{initialize_readline()} which
162 performs this and other desired initializations, such as installing
163 custom completers (@pxref{Custom Completers}).
165 @node Custom Functions
166 @section Custom Functions
168 Readline provides many functions for manipulating the text of
169 the line, but it isn't possible to anticipate the needs of all
170 programs. This section describes the various functions and variables
171 defined within the Readline library which allow a user program to add
172 customized functionality to Readline.
174 Before declaring any functions that customize Readline's behavior, or
175 using any functionality Readline provides in other code, an
176 application writer should include the file @code{<readline/readline.h>}
177 in any file that uses Readline's features. Since some of the definitions
178 in @code{readline.h} use the @code{stdio} library, the file
179 @code{<stdio.h>} should be included before @code{readline.h}.
181 @code{readline.h} defines a C preprocessor variable that should
182 be treated as an integer, @code{RL_READLINE_VERSION}, which may
183 be used to conditionally compile application code depending on
184 the installed Readline version. The value is a hexadecimal
185 encoding of the major and minor version numbers of the library,
186 of the form 0x@var{MMmm}. @var{MM} is the two-digit major
187 version number; @var{mm} is the two-digit minor version number.
188 For Readline 4.2, for example, the value of
189 @code{RL_READLINE_VERSION} would be @code{0x0402}.
192 * Readline Typedefs:: C declarations to make code readable.
193 * Function Writing:: Variables and calling conventions.
196 @node Readline Typedefs
197 @subsection Readline Typedefs
199 For readabilty, we declare a number of new object types, all pointers
202 The reason for declaring these new types is to make it easier to write
203 code describing pointers to C functions with appropriately prototyped
204 arguments and return values.
206 For instance, say we want to declare a variable @var{func} as a pointer
207 to a function which takes two @code{int} arguments and returns an
208 @code{int} (this is the type of all of the Readline bindable functions).
209 Instead of the classic C declaration
211 @code{int (*func)();}
214 or the ANSI-C style declaration
216 @code{int (*func)(int, int);}
221 @code{rl_command_func_t *func;}
223 The full list of function pointer types available is
226 @item typedef int rl_command_func_t (int, int);
228 @item typedef char *rl_compentry_func_t (const char *, int);
230 @item typedef char **rl_completion_func_t (const char *, int, int);
232 @item typedef char *rl_quote_func_t (char *, int, char *);
234 @item typedef char *rl_dequote_func_t (char *, int);
236 @item typedef int rl_compignore_func_t (char **);
238 @item typedef void rl_compdisp_func_t (char **, int, int);
240 @item typedef int rl_hook_func_t (void);
242 @item typedef int rl_getc_func_t (FILE *);
244 @item typedef int rl_linebuf_func_t (char *, int);
246 @item typedef int rl_intfunc_t (int);
247 @item #define rl_ivoidfunc_t rl_hook_func_t
248 @item typedef int rl_icpfunc_t (char *);
249 @item typedef int rl_icppfunc_t (char **);
251 @item typedef void rl_voidfunc_t (void);
252 @item typedef void rl_vintfunc_t (int);
253 @item typedef void rl_vcpfunc_t (char *);
254 @item typedef void rl_vcppfunc_t (char **);
258 @node Function Writing
259 @subsection Writing a New Function
261 In order to write new functions for Readline, you need to know the
262 calling conventions for keyboard-invoked functions, and the names of the
263 variables that describe the current state of the line read so far.
265 The calling sequence for a command @code{foo} looks like
268 @code{int foo (int count, int key)}
272 where @var{count} is the numeric argument (or 1 if defaulted) and
273 @var{key} is the key that invoked this function.
275 It is completely up to the function as to what should be done with the
276 numeric argument. Some functions use it as a repeat count, some
277 as a flag, and others to choose alternate behavior (refreshing the current
278 line as opposed to refreshing the screen, for example). Some choose to
279 ignore it. In general, if a
280 function uses the numeric argument as a repeat count, it should be able
281 to do something useful with both negative and positive arguments.
282 At the very least, it should be aware that it can be passed a
285 A command function should return 0 if its action completes successfully,
286 and a non-zero value if some error occurs.
287 This is the convention obeyed by all of the builtin Readline bindable
290 @node Readline Variables
291 @section Readline Variables
293 These variables are available to function writers.
295 @deftypevar {char *} rl_line_buffer
296 This is the line gathered so far. You are welcome to modify the
297 contents of the line, but see @ref{Allowing Undoing}. The
298 function @code{rl_extend_line_buffer} is available to increase
299 the memory allocated to @code{rl_line_buffer}.
302 @deftypevar int rl_point
303 The offset of the current cursor position in @code{rl_line_buffer}
307 @deftypevar int rl_end
308 The number of characters present in @code{rl_line_buffer}. When
309 @code{rl_point} is at the end of the line, @code{rl_point} and
310 @code{rl_end} are equal.
313 @deftypevar int rl_mark
314 The @var{mark} (saved position) in the current line. If set, the mark
315 and point define a @emph{region}.
318 @deftypevar int rl_done
319 Setting this to a non-zero value causes Readline to return the current
323 @deftypevar int rl_num_chars_to_read
324 Setting this to a positive value before calling @code{readline()} causes
325 Readline to return after accepting that many characters, rather
326 than reading up to a character bound to @code{accept-line}.
329 @deftypevar int rl_pending_input
330 Setting this to a value makes it the next keystroke read. This is a
331 way to stuff a single character into the input stream.
334 @deftypevar int rl_dispatching
335 Set to a non-zero value if a function is being called from a key binding;
336 zero otherwise. Application functions can test this to discover whether
337 they were called directly or by Readline's dispatching mechanism.
340 @deftypevar int rl_erase_empty_line
341 Setting this to a non-zero value causes Readline to completely erase
342 the current line, including any prompt, any time a newline is typed as
343 the only character on an otherwise-empty line. The cursor is moved to
344 the beginning of the newly-blank line.
347 @deftypevar {char *} rl_prompt
348 The prompt Readline uses. This is set from the argument to
349 @code{readline()}, and should not be assigned to directly.
350 The @code{rl_set_prompt()} function (@pxref{Redisplay}) may
351 be used to modify the prompt string after calling @code{readline()}.
354 @deftypevar int rl_already_prompted
355 If an application wishes to display the prompt itself, rather than have
356 Readline do it the first time @code{readline()} is called, it should set
357 this variable to a non-zero value after displaying the prompt.
358 The prompt must also be passed as the argument to @code{readline()} so
359 the redisplay functions can update the display properly.
360 The calling application is responsible for managing the value; Readline
364 @deftypevar {const char *} rl_library_version
365 The version number of this revision of the library.
368 @deftypevar int rl_readline_version
369 An integer encoding the current version of the library. The encoding is
370 of the form 0x@var{MMmm}, where @var{MM} is the two-digit major version
371 number, and @var{mm} is the two-digit minor version number.
372 For example, for Readline-4.2, @code{rl_readline_version} would have the
376 @deftypevar {int} rl_gnu_readline_p
377 Always set to 1, denoting that this is @sc{gnu} readline rather than some
381 @deftypevar {const char *} rl_terminal_name
382 The terminal type, used for initialization. If not set by the application,
383 Readline sets this to the value of the @env{TERM} environment variable
384 the first time it is called.
387 @deftypevar {const char *} rl_readline_name
388 This variable is set to a unique name by each application using Readline.
389 The value allows conditional parsing of the inputrc file
390 (@pxref{Conditional Init Constructs}).
393 @deftypevar {FILE *} rl_instream
394 The stdio stream from which Readline reads input.
395 If @code{NULL}, Readline defaults to @var{stdin}.
398 @deftypevar {FILE *} rl_outstream
399 The stdio stream to which Readline performs output.
400 If @code{NULL}, Readline defaults to @var{stdout}.
403 @deftypevar int rl_prefer_env_winsize
404 If non-zero, Readline gives values found in the @env{LINES} and
405 @env{COLUMNS} environment variables greater precedence than values fetched
406 from the kernel when computing the screen dimensions.
409 @deftypevar {rl_command_func_t *} rl_last_func
410 The address of the last command function Readline executed. May be used to
411 test whether or not a function is being executed twice in succession, for
415 @deftypevar {rl_hook_func_t *} rl_startup_hook
416 If non-zero, this is the address of a function to call just
417 before @code{readline} prints the first prompt.
420 @deftypevar {rl_hook_func_t *} rl_pre_input_hook
421 If non-zero, this is the address of a function to call after
422 the first prompt has been printed and just before @code{readline}
423 starts reading input characters.
426 @deftypevar {rl_hook_func_t *} rl_event_hook
427 If non-zero, this is the address of a function to call periodically
428 when Readline is waiting for terminal input.
429 By default, this will be called at most ten times a second if there
430 is no keyboard input.
433 @deftypevar {rl_getc_func_t *} rl_getc_function
434 If non-zero, Readline will call indirectly through this pointer
435 to get a character from the input stream. By default, it is set to
436 @code{rl_getc}, the default Readline character input function
437 (@pxref{Character Input}).
440 @deftypevar {rl_voidfunc_t *} rl_redisplay_function
441 If non-zero, Readline will call indirectly through this pointer
442 to update the display with the current contents of the editing buffer.
443 By default, it is set to @code{rl_redisplay}, the default Readline
444 redisplay function (@pxref{Redisplay}).
447 @deftypevar {rl_vintfunc_t *} rl_prep_term_function
448 If non-zero, Readline will call indirectly through this pointer
449 to initialize the terminal. The function takes a single argument, an
450 @code{int} flag that says whether or not to use eight-bit characters.
451 By default, this is set to @code{rl_prep_terminal}
452 (@pxref{Terminal Management}).
455 @deftypevar {rl_voidfunc_t *} rl_deprep_term_function
456 If non-zero, Readline will call indirectly through this pointer
457 to reset the terminal. This function should undo the effects of
458 @code{rl_prep_term_function}.
459 By default, this is set to @code{rl_deprep_terminal}
460 (@pxref{Terminal Management}).
463 @deftypevar {Keymap} rl_executing_keymap
464 This variable is set to the keymap (@pxref{Keymaps}) in which the
465 currently executing readline function was found.
468 @deftypevar {Keymap} rl_binding_keymap
469 This variable is set to the keymap (@pxref{Keymaps}) in which the
470 last key binding occurred.
473 @deftypevar {char *} rl_executing_macro
474 This variable is set to the text of any currently-executing macro.
477 @deftypevar {int} rl_readline_state
478 A variable with bit values that encapsulate the current Readline state.
479 A bit is set with the @code{RL_SETSTATE} macro, and unset with the
480 @code{RL_UNSETSTATE} macro. Use the @code{RL_ISSTATE} macro to test
481 whether a particular state bit is set. Current state bits include:
485 Readline has not yet been called, nor has it begun to intialize.
486 @item RL_STATE_INITIALIZING
487 Readline is initializing its internal data structures.
488 @item RL_STATE_INITIALIZED
489 Readline has completed its initialization.
490 @item RL_STATE_TERMPREPPED
491 Readline has modified the terminal modes to do its own input and redisplay.
492 @item RL_STATE_READCMD
493 Readline is reading a command from the keyboard.
494 @item RL_STATE_METANEXT
495 Readline is reading more input after reading the meta-prefix character.
496 @item RL_STATE_DISPATCHING
497 Readline is dispatching to a command.
498 @item RL_STATE_MOREINPUT
499 Readline is reading more input while executing an editing command.
500 @item RL_STATE_ISEARCH
501 Readline is performing an incremental history search.
502 @item RL_STATE_NSEARCH
503 Readline is performing a non-incremental history search.
504 @item RL_STATE_SEARCH
505 Readline is searching backward or forward through the history for a string.
506 @item RL_STATE_NUMERICARG
507 Readline is reading a numeric argument.
508 @item RL_STATE_MACROINPUT
509 Readline is currently getting its input from a previously-defined keyboard
511 @item RL_STATE_MACRODEF
512 Readline is currently reading characters defining a keyboard macro.
513 @item RL_STATE_OVERWRITE
514 Readline is in overwrite mode.
515 @item RL_STATE_COMPLETING
516 Readline is performing word completion.
517 @item RL_STATE_SIGHANDLER
518 Readline is currently executing the readline signal handler.
519 @item RL_STATE_UNDOING
520 Readline is performing an undo.
522 Readline has read a key sequence bound to @code{accept-line}
523 and is about to return the line to the caller.
528 @deftypevar {int} rl_explicit_arg
529 Set to a non-zero value if an explicit numeric argument was specified by
530 the user. Only valid in a bindable command function.
533 @deftypevar {int} rl_numeric_arg
534 Set to the value of any numeric argument explicitly specified by the user
535 before executing the current Readline function. Only valid in a bindable
539 @deftypevar {int} rl_editing_mode
540 Set to a value denoting Readline's current editing mode. A value of
541 @var{1} means Readline is currently in emacs mode; @var{0}
542 means that vi mode is active.
546 @node Readline Convenience Functions
547 @section Readline Convenience Functions
550 * Function Naming:: How to give a function you write a name.
551 * Keymaps:: Making keymaps.
552 * Binding Keys:: Changing Keymaps.
553 * Associating Function Names and Bindings:: Translate function names to
555 * Allowing Undoing:: How to make your functions undoable.
556 * Redisplay:: Functions to control line display.
557 * Modifying Text:: Functions to modify @code{rl_line_buffer}.
558 * Character Input:: Functions to read keyboard input.
559 * Terminal Management:: Functions to manage terminal settings.
560 * Utility Functions:: Generally useful functions and hooks.
561 * Miscellaneous Functions:: Functions that don't fall into any category.
562 * Alternate Interface:: Using Readline in a `callback' fashion.
563 * A Readline Example:: An example Readline function.
566 @node Function Naming
567 @subsection Naming a Function
569 The user can dynamically change the bindings of keys while using
570 Readline. This is done by representing the function with a descriptive
571 name. The user is able to type the descriptive name when referring to
572 the function. Thus, in an init file, one might find
575 Meta-Rubout: backward-kill-word
578 This binds the keystroke @key{Meta-Rubout} to the function
579 @emph{descriptively} named @code{backward-kill-word}. You, as the
580 programmer, should bind the functions you write to descriptive names as
581 well. Readline provides a function for doing that:
583 @deftypefun int rl_add_defun (const char *name, rl_command_func_t *function, int key)
584 Add @var{name} to the list of named functions. Make @var{function} be
585 the function that gets called. If @var{key} is not -1, then bind it to
586 @var{function} using @code{rl_bind_key()}.
589 Using this function alone is sufficient for most applications.
590 It is the recommended way to add a few functions to the default
591 functions that Readline has built in.
592 If you need to do something other than adding a function to Readline,
593 you may need to use the underlying functions described below.
596 @subsection Selecting a Keymap
598 Key bindings take place on a @dfn{keymap}. The keymap is the
599 association between the keys that the user types and the functions that
600 get run. You can make your own keymaps, copy existing keymaps, and tell
601 Readline which keymap to use.
603 @deftypefun Keymap rl_make_bare_keymap (void)
604 Returns a new, empty keymap. The space for the keymap is allocated with
605 @code{malloc()}; the caller should free it by calling
606 @code{rl_discard_keymap()} when done.
609 @deftypefun Keymap rl_copy_keymap (Keymap map)
610 Return a new keymap which is a copy of @var{map}.
613 @deftypefun Keymap rl_make_keymap (void)
614 Return a new keymap with the printing characters bound to rl_insert,
615 the lowercase Meta characters bound to run their equivalents, and
616 the Meta digits bound to produce numeric arguments.
619 @deftypefun void rl_discard_keymap (Keymap keymap)
620 Free the storage associated with @var{keymap}.
623 Readline has several internal keymaps. These functions allow you to
624 change which keymap is active.
626 @deftypefun Keymap rl_get_keymap (void)
627 Returns the currently active keymap.
630 @deftypefun void rl_set_keymap (Keymap keymap)
631 Makes @var{keymap} the currently active keymap.
634 @deftypefun Keymap rl_get_keymap_by_name (const char *name)
635 Return the keymap matching @var{name}. @var{name} is one which would
636 be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
639 @deftypefun {char *} rl_get_keymap_name (Keymap keymap)
640 Return the name matching @var{keymap}. @var{name} is one which would
641 be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
645 @subsection Binding Keys
647 Key sequences are associate with functions through the keymap.
648 Readline has several internal keymaps: @code{emacs_standard_keymap},
649 @code{emacs_meta_keymap}, @code{emacs_ctlx_keymap},
650 @code{vi_movement_keymap}, and @code{vi_insertion_keymap}.
651 @code{emacs_standard_keymap} is the default, and the examples in
652 this manual assume that.
654 Since @code{readline()} installs a set of default key bindings the first
655 time it is called, there is always the danger that a custom binding
656 installed before the first call to @code{readline()} will be overridden.
657 An alternate mechanism is to install custom key bindings in an
658 initialization function assigned to the @code{rl_startup_hook} variable
659 (@pxref{Readline Variables}).
661 These functions manage key bindings.
663 @deftypefun int rl_bind_key (int key, rl_command_func_t *function)
664 Binds @var{key} to @var{function} in the currently active keymap.
665 Returns non-zero in the case of an invalid @var{key}.
668 @deftypefun int rl_bind_key_in_map (int key, rl_command_func_t *function, Keymap map)
669 Bind @var{key} to @var{function} in @var{map}.
670 Returns non-zero in the case of an invalid @var{key}.
673 @deftypefun int rl_bind_key_if_unbound (int key, rl_command_func_t *function)
674 Binds @var{key} to @var{function} if it is not already bound in the
675 currently active keymap.
676 Returns non-zero in the case of an invalid @var{key} or if @var{key} is
680 @deftypefun int rl_bind_key_if_unbound_in_map (int key, rl_command_func_t *function, Keymap map)
681 Binds @var{key} to @var{function} if it is not already bound in @var{map}.
682 Returns non-zero in the case of an invalid @var{key} or if @var{key} is
686 @deftypefun int rl_unbind_key (int key)
687 Bind @var{key} to the null function in the currently active keymap.
688 Returns non-zero in case of error.
691 @deftypefun int rl_unbind_key_in_map (int key, Keymap map)
692 Bind @var{key} to the null function in @var{map}.
693 Returns non-zero in case of error.
696 @deftypefun int rl_unbind_function_in_map (rl_command_func_t *function, Keymap map)
697 Unbind all keys that execute @var{function} in @var{map}.
700 @deftypefun int rl_unbind_command_in_map (const char *command, Keymap map)
701 Unbind all keys that are bound to @var{command} in @var{map}.
704 @deftypefun int rl_bind_keyseq (const char *keyseq, rl_command_func_t *function)
705 Bind the key sequence represented by the string @var{keyseq} to the function
706 @var{function}, beginning in the current keymap.
707 This makes new keymaps as necessary.
708 The return value is non-zero if @var{keyseq} is invalid.
711 @deftypefun int rl_bind_keyseq_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
712 Bind the key sequence represented by the string @var{keyseq} to the function
713 @var{function}. This makes new keymaps as necessary.
714 Initial bindings are performed in @var{map}.
715 The return value is non-zero if @var{keyseq} is invalid.
718 @deftypefun int rl_set_key (const char *keyseq, rl_command_func_t *function, Keymap map)
719 Equivalent to @code{rl_bind_keyseq_in_map}.
722 @deftypefun int rl_bind_keyseq_if_unbound (const char *keyseq, rl_command_func_t *function)
723 Binds @var{keyseq} to @var{function} if it is not already bound in the
724 currently active keymap.
725 Returns non-zero in the case of an invalid @var{keyseq} or if @var{keyseq} is
729 @deftypefun int rl_bind_keyseq_if_unbound_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
730 Binds @var{keyseq} to @var{function} if it is not already bound in @var{map}.
731 Returns non-zero in the case of an invalid @var{keyseq} or if @var{keyseq} is
735 @deftypefun int rl_generic_bind (int type, const char *keyseq, char *data, Keymap map)
736 Bind the key sequence represented by the string @var{keyseq} to the arbitrary
737 pointer @var{data}. @var{type} says what kind of data is pointed to by
738 @var{data}; this can be a function (@code{ISFUNC}), a macro
739 (@code{ISMACR}), or a keymap (@code{ISKMAP}). This makes new keymaps as
740 necessary. The initial keymap in which to do bindings is @var{map}.
743 @deftypefun int rl_parse_and_bind (char *line)
744 Parse @var{line} as if it had been read from the @code{inputrc} file and
745 perform any key bindings and variable assignments found
746 (@pxref{Readline Init File}).
749 @deftypefun int rl_read_init_file (const char *filename)
750 Read keybindings and variable assignments from @var{filename}
751 (@pxref{Readline Init File}).
754 @node Associating Function Names and Bindings
755 @subsection Associating Function Names and Bindings
757 These functions allow you to find out what keys invoke named functions
758 and the functions invoked by a particular key sequence. You may also
759 associate a new function name with an arbitrary function.
761 @deftypefun {rl_command_func_t *} rl_named_function (const char *name)
762 Return the function with name @var{name}.
765 @deftypefun {rl_command_func_t *} rl_function_of_keyseq (const char *keyseq, Keymap map, int *type)
766 Return the function invoked by @var{keyseq} in keymap @var{map}.
767 If @var{map} is @code{NULL}, the current keymap is used. If @var{type} is
768 not @code{NULL}, the type of the object is returned in the @code{int} variable
769 it points to (one of @code{ISFUNC}, @code{ISKMAP}, or @code{ISMACR}).
772 @deftypefun {char **} rl_invoking_keyseqs (rl_command_func_t *function)
773 Return an array of strings representing the key sequences used to
774 invoke @var{function} in the current keymap.
777 @deftypefun {char **} rl_invoking_keyseqs_in_map (rl_command_func_t *function, Keymap map)
778 Return an array of strings representing the key sequences used to
779 invoke @var{function} in the keymap @var{map}.
782 @deftypefun void rl_function_dumper (int readable)
783 Print the readline function names and the key sequences currently
784 bound to them to @code{rl_outstream}. If @var{readable} is non-zero,
785 the list is formatted in such a way that it can be made part of an
786 @code{inputrc} file and re-read.
789 @deftypefun void rl_list_funmap_names (void)
790 Print the names of all bindable Readline functions to @code{rl_outstream}.
793 @deftypefun {const char **} rl_funmap_names (void)
794 Return a NULL terminated array of known function names. The array is
795 sorted. The array itself is allocated, but not the strings inside. You
796 should @code{free()} the array when you are done, but not the pointers.
799 @deftypefun int rl_add_funmap_entry (const char *name, rl_command_func_t *function)
800 Add @var{name} to the list of bindable Readline command names, and make
801 @var{function} the function to be called when @var{name} is invoked.
804 @node Allowing Undoing
805 @subsection Allowing Undoing
807 Supporting the undo command is a painless thing, and makes your
808 functions much more useful. It is certainly easy to try
809 something if you know you can undo it.
811 If your function simply inserts text once, or deletes text once, and
812 uses @code{rl_insert_text()} or @code{rl_delete_text()} to do it, then
813 undoing is already done for you automatically.
815 If you do multiple insertions or multiple deletions, or any combination
816 of these operations, you should group them together into one operation.
817 This is done with @code{rl_begin_undo_group()} and
818 @code{rl_end_undo_group()}.
820 The types of events that can be undone are:
823 enum undo_code @{ UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END @};
826 Notice that @code{UNDO_DELETE} means to insert some text, and
827 @code{UNDO_INSERT} means to delete some text. That is, the undo code
828 tells what to undo, not how to undo it. @code{UNDO_BEGIN} and
829 @code{UNDO_END} are tags added by @code{rl_begin_undo_group()} and
830 @code{rl_end_undo_group()}.
832 @deftypefun int rl_begin_undo_group (void)
833 Begins saving undo information in a group construct. The undo
834 information usually comes from calls to @code{rl_insert_text()} and
835 @code{rl_delete_text()}, but could be the result of calls to
836 @code{rl_add_undo()}.
839 @deftypefun int rl_end_undo_group (void)
840 Closes the current undo group started with @code{rl_begin_undo_group
841 ()}. There should be one call to @code{rl_end_undo_group()}
842 for each call to @code{rl_begin_undo_group()}.
845 @deftypefun void rl_add_undo (enum undo_code what, int start, int end, char *text)
846 Remember how to undo an event (according to @var{what}). The affected
847 text runs from @var{start} to @var{end}, and encompasses @var{text}.
850 @deftypefun void rl_free_undo_list (void)
851 Free the existing undo list.
854 @deftypefun int rl_do_undo (void)
855 Undo the first thing on the undo list. Returns @code{0} if there was
856 nothing to undo, non-zero if something was undone.
859 Finally, if you neither insert nor delete text, but directly modify the
860 existing text (e.g., change its case), call @code{rl_modifying()}
861 once, just before you modify the text. You must supply the indices of
862 the text range that you are going to modify.
864 @deftypefun int rl_modifying (int start, int end)
865 Tell Readline to save the text between @var{start} and @var{end} as a
866 single undo unit. It is assumed that you will subsequently modify
871 @subsection Redisplay
873 @deftypefun void rl_redisplay (void)
874 Change what's displayed on the screen to reflect the current contents
875 of @code{rl_line_buffer}.
878 @deftypefun int rl_forced_update_display (void)
879 Force the line to be updated and redisplayed, whether or not
880 Readline thinks the screen display is correct.
883 @deftypefun int rl_on_new_line (void)
884 Tell the update functions that we have moved onto a new (empty) line,
885 usually after ouputting a newline.
888 @deftypefun int rl_on_new_line_with_prompt (void)
889 Tell the update functions that we have moved onto a new line, with
890 @var{rl_prompt} already displayed.
891 This could be used by applications that want to output the prompt string
892 themselves, but still need Readline to know the prompt string length for
894 It should be used after setting @var{rl_already_prompted}.
897 @deftypefun int rl_reset_line_state (void)
898 Reset the display state to a clean state and redisplay the current line
899 starting on a new line.
902 @deftypefun int rl_crlf (void)
903 Move the cursor to the start of the next screen line.
906 @deftypefun int rl_show_char (int c)
907 Display character @var{c} on @code{rl_outstream}.
908 If Readline has not been set to display meta characters directly, this
909 will convert meta characters to a meta-prefixed key sequence.
910 This is intended for use by applications which wish to do their own
914 @deftypefun int rl_message (const char *, @dots{})
915 The arguments are a format string as would be supplied to @code{printf},
916 possibly containing conversion specifications such as @samp{%d}, and
917 any additional arguments necessary to satisfy the conversion specifications.
918 The resulting string is displayed in the @dfn{echo area}. The echo area
919 is also used to display numeric arguments and search strings.
920 You should call @code{rl_save_prompt} to save the prompt information
921 before calling this function.
924 @deftypefun int rl_clear_message (void)
925 Clear the message in the echo area. If the prompt was saved with a call to
926 @code{rl_save_prompt} before the last call to @code{rl_message},
927 call @code{rl_restore_prompt} before calling this function.
930 @deftypefun void rl_save_prompt (void)
931 Save the local Readline prompt display state in preparation for
932 displaying a new message in the message area with @code{rl_message()}.
935 @deftypefun void rl_restore_prompt (void)
936 Restore the local Readline prompt display state saved by the most
937 recent call to @code{rl_save_prompt}.
938 if @code{rl_save_prompt} was called to save the prompt before a call
939 to @code{rl_message}, this function should be called before the
940 corresponding call to @code{rl_clear_message}.
943 @deftypefun int rl_expand_prompt (char *prompt)
944 Expand any special character sequences in @var{prompt} and set up the
945 local Readline prompt redisplay variables.
946 This function is called by @code{readline()}. It may also be called to
947 expand the primary prompt if the @code{rl_on_new_line_with_prompt()}
948 function or @code{rl_already_prompted} variable is used.
949 It returns the number of visible characters on the last line of the
950 (possibly multi-line) prompt.
951 Applications may indicate that the prompt contains characters that take
952 up no physical screen space when displayed by bracketing a sequence of
953 such characters with the special markers @code{RL_PROMPT_START_IGNORE}
954 and @code{RL_PROMPT_END_IGNORE} (declared in @file{readline.h}. This may
955 be used to embed terminal-specific escape sequences in prompts.
958 @deftypefun int rl_set_prompt (const char *prompt)
959 Make Readline use @var{prompt} for subsequent redisplay. This calls
960 @code{rl_expand_prompt()} to expand the prompt and sets @code{rl_prompt}
965 @subsection Modifying Text
967 @deftypefun int rl_insert_text (const char *text)
968 Insert @var{text} into the line at the current cursor position.
969 Returns the number of characters inserted.
972 @deftypefun int rl_delete_text (int start, int end)
973 Delete the text between @var{start} and @var{end} in the current line.
974 Returns the number of characters deleted.
977 @deftypefun {char *} rl_copy_text (int start, int end)
978 Return a copy of the text between @var{start} and @var{end} in
982 @deftypefun int rl_kill_text (int start, int end)
983 Copy the text between @var{start} and @var{end} in the current line
984 to the kill ring, appending or prepending to the last kill if the
985 last command was a kill command. The text is deleted.
986 If @var{start} is less than @var{end},
987 the text is appended, otherwise prepended. If the last command was
988 not a kill, a new kill ring slot is used.
991 @deftypefun int rl_push_macro_input (char *macro)
992 Cause @var{macro} to be inserted into the line, as if it had been invoked
993 by a key bound to a macro. Not especially useful; use
994 @code{rl_insert_text()} instead.
997 @node Character Input
998 @subsection Character Input
1000 @deftypefun int rl_read_key (void)
1001 Return the next character available from Readline's current input stream.
1002 This handles input inserted into
1003 the input stream via @var{rl_pending_input} (@pxref{Readline Variables})
1004 and @code{rl_stuff_char()}, macros, and characters read from the keyboard.
1005 While waiting for input, this function will call any function assigned to
1006 the @code{rl_event_hook} variable.
1009 @deftypefun int rl_getc (FILE *stream)
1010 Return the next character available from @var{stream}, which is assumed to
1014 @deftypefun int rl_stuff_char (int c)
1015 Insert @var{c} into the Readline input stream. It will be "read"
1016 before Readline attempts to read characters from the terminal with
1017 @code{rl_read_key()}. Up to 512 characters may be pushed back.
1018 @code{rl_stuff_char} returns 1 if the character was successfully inserted;
1022 @deftypefun int rl_execute_next (int c)
1023 Make @var{c} be the next command to be executed when @code{rl_read_key()}
1024 is called. This sets @var{rl_pending_input}.
1027 @deftypefun int rl_clear_pending_input (void)
1028 Unset @var{rl_pending_input}, effectively negating the effect of any
1029 previous call to @code{rl_execute_next()}. This works only if the
1030 pending input has not already been read with @code{rl_read_key()}.
1033 @deftypefun int rl_set_keyboard_input_timeout (int u)
1034 While waiting for keyboard input in @code{rl_read_key()}, Readline will
1035 wait for @var{u} microseconds for input before calling any function
1036 assigned to @code{rl_event_hook}. The default waiting period is
1037 one-tenth of a second. Returns the old timeout value.
1040 @node Terminal Management
1041 @subsection Terminal Management
1043 @deftypefun void rl_prep_terminal (int meta_flag)
1044 Modify the terminal settings for Readline's use, so @code{readline()}
1045 can read a single character at a time from the keyboard.
1046 The @var{meta_flag} argument should be non-zero if Readline should
1047 read eight-bit input.
1050 @deftypefun void rl_deprep_terminal (void)
1051 Undo the effects of @code{rl_prep_terminal()}, leaving the terminal in
1052 the state in which it was before the most recent call to
1053 @code{rl_prep_terminal()}.
1056 @deftypefun void rl_tty_set_default_bindings (Keymap kmap)
1057 Read the operating system's terminal editing characters (as would be
1058 displayed by @code{stty}) to their Readline equivalents.
1059 The bindings are performed in @var{kmap}.
1062 @deftypefun void rl_tty_unset_default_bindings (Keymap kmap)
1063 Reset the bindings manipulated by @code{rl_tty_set_default_bindings} so
1064 that the terminal editing characters are bound to @code{rl_insert}.
1065 The bindings are performed in @var{kmap}.
1068 @deftypefun int rl_reset_terminal (const char *terminal_name)
1069 Reinitialize Readline's idea of the terminal settings using
1070 @var{terminal_name} as the terminal type (e.g., @code{vt100}).
1071 If @var{terminal_name} is @code{NULL}, the value of the @code{TERM}
1072 environment variable is used.
1075 @node Utility Functions
1076 @subsection Utility Functions
1078 @deftypefun void rl_replace_line (const char *text, int clear_undo)
1079 Replace the contents of @code{rl_line_buffer} with @var{text}.
1080 The point and mark are preserved, if possible.
1081 If @var{clear_undo} is non-zero, the undo list associated with the
1082 current line is cleared.
1085 @deftypefun int rl_extend_line_buffer (int len)
1086 Ensure that @code{rl_line_buffer} has enough space to hold @var{len}
1087 characters, possibly reallocating it if necessary.
1090 @deftypefun int rl_initialize (void)
1091 Initialize or re-initialize Readline's internal state.
1092 It's not strictly necessary to call this; @code{readline()} calls it before
1096 @deftypefun int rl_ding (void)
1097 Ring the terminal bell, obeying the setting of @code{bell-style}.
1100 @deftypefun int rl_alphabetic (int c)
1101 Return 1 if @var{c} is an alphabetic character.
1104 @deftypefun void rl_display_match_list (char **matches, int len, int max)
1105 A convenience function for displaying a list of strings in
1106 columnar format on Readline's output stream. @code{matches} is the list
1107 of strings, in argv format, such as a list of completion matches.
1108 @code{len} is the number of strings in @code{matches}, and @code{max}
1109 is the length of the longest string in @code{matches}. This function uses
1110 the setting of @code{print-completions-horizontally} to select how the
1111 matches are displayed (@pxref{Readline Init File Syntax}).
1114 The following are implemented as macros, defined in @code{chardefs.h}.
1115 Applications should refrain from using them.
1117 @deftypefun int _rl_uppercase_p (int c)
1118 Return 1 if @var{c} is an uppercase alphabetic character.
1121 @deftypefun int _rl_lowercase_p (int c)
1122 Return 1 if @var{c} is a lowercase alphabetic character.
1125 @deftypefun int _rl_digit_p (int c)
1126 Return 1 if @var{c} is a numeric character.
1129 @deftypefun int _rl_to_upper (int c)
1130 If @var{c} is a lowercase alphabetic character, return the corresponding
1131 uppercase character.
1134 @deftypefun int _rl_to_lower (int c)
1135 If @var{c} is an uppercase alphabetic character, return the corresponding
1136 lowercase character.
1139 @deftypefun int _rl_digit_value (int c)
1140 If @var{c} is a number, return the value it represents.
1143 @node Miscellaneous Functions
1144 @subsection Miscellaneous Functions
1146 @deftypefun int rl_macro_bind (const char *keyseq, const char *macro, Keymap map)
1147 Bind the key sequence @var{keyseq} to invoke the macro @var{macro}.
1148 The binding is performed in @var{map}. When @var{keyseq} is invoked, the
1149 @var{macro} will be inserted into the line. This function is deprecated;
1150 use @code{rl_generic_bind()} instead.
1153 @deftypefun void rl_macro_dumper (int readable)
1154 Print the key sequences bound to macros and their values, using
1155 the current keymap, to @code{rl_outstream}.
1156 If @var{readable} is non-zero, the list is formatted in such a way
1157 that it can be made part of an @code{inputrc} file and re-read.
1160 @deftypefun int rl_variable_bind (const char *variable, const char *value)
1161 Make the Readline variable @var{variable} have @var{value}.
1162 This behaves as if the readline command
1163 @samp{set @var{variable} @var{value}} had been executed in an @code{inputrc}
1164 file (@pxref{Readline Init File Syntax}).
1167 @deftypefun {char *} rl_variable_value (const char *variable)
1168 Return a string representing the value of the Readline variable @var{variable}.
1169 For boolean variables, this string is either @samp{on} or @samp{off}.
1172 @deftypefun void rl_variable_dumper (int readable)
1173 Print the readline variable names and their current values
1174 to @code{rl_outstream}.
1175 If @var{readable} is non-zero, the list is formatted in such a way
1176 that it can be made part of an @code{inputrc} file and re-read.
1179 @deftypefun int rl_set_paren_blink_timeout (int u)
1180 Set the time interval (in microseconds) that Readline waits when showing
1181 a balancing character when @code{blink-matching-paren} has been enabled.
1184 @deftypefun {char *} rl_get_termcap (const char *cap)
1185 Retrieve the string value of the termcap capability @var{cap}.
1186 Readline fetches the termcap entry for the current terminal name and
1187 uses those capabilities to move around the screen line and perform other
1188 terminal-specific operations, like erasing a line. Readline does not
1189 use all of a terminal's capabilities, and this function will return
1190 values for only those capabilities Readline uses.
1193 @node Alternate Interface
1194 @subsection Alternate Interface
1196 An alternate interface is available to plain @code{readline()}. Some
1197 applications need to interleave keyboard I/O with file, device, or
1198 window system I/O, typically by using a main loop to @code{select()}
1199 on various file descriptors. To accomodate this need, readline can
1200 also be invoked as a `callback' function from an event loop. There
1201 are functions available to make this easy.
1203 @deftypefun void rl_callback_handler_install (const char *prompt, rl_vcpfunc_t *lhandler)
1204 Set up the terminal for readline I/O and display the initial
1205 expanded value of @var{prompt}. Save the value of @var{lhandler} to
1206 use as a function to call when a complete line of input has been entered.
1207 The function takes the text of the line as an argument.
1210 @deftypefun void rl_callback_read_char (void)
1211 Whenever an application determines that keyboard input is available, it
1212 should call @code{rl_callback_read_char()}, which will read the next
1213 character from the current input source.
1214 If that character completes the line, @code{rl_callback_read_char} will
1215 invoke the @var{lhandler} function saved by @code{rl_callback_handler_install}
1216 to process the line.
1217 Before calling the @var{lhandler} function, the terminal settings are
1218 reset to the values they had before calling
1219 @code{rl_callback_handler_install}.
1220 If the @var{lhandler} function returns,
1221 the terminal settings are modified for Readline's use again.
1222 @code{EOF} is indicated by calling @var{lhandler} with a
1226 @deftypefun void rl_callback_handler_remove (void)
1227 Restore the terminal to its initial state and remove the line handler.
1228 This may be called from within a callback as well as independently.
1229 If the @var{lhandler} installed by @code{rl_callback_handler_install}
1230 does not exit the program, either this function or the function referred
1231 to by the value of @code{rl_deprep_term_function} should be called before
1232 the program exits to reset the terminal settings.
1235 @node A Readline Example
1236 @subsection A Readline Example
1238 Here is a function which changes lowercase characters to their uppercase
1239 equivalents, and uppercase characters to lowercase. If
1240 this function was bound to @samp{M-c}, then typing @samp{M-c} would
1241 change the case of the character under point. Typing @samp{M-1 0 M-c}
1242 would change the case of the following 10 characters, leaving the cursor on
1243 the last character changed.
1246 /* Invert the case of the COUNT following characters. */
1248 invert_case_line (count, key)
1251 register int start, end, i;
1255 if (rl_point >= rl_end)
1266 /* Find the end of the range to modify. */
1267 end = start + (count * direction);
1269 /* Force it to be within range. */
1285 /* Tell readline that we are modifying the line,
1286 so it will save the undo information. */
1287 rl_modifying (start, end);
1289 for (i = start; i != end; i++)
1291 if (_rl_uppercase_p (rl_line_buffer[i]))
1292 rl_line_buffer[i] = _rl_to_lower (rl_line_buffer[i]);
1293 else if (_rl_lowercase_p (rl_line_buffer[i]))
1294 rl_line_buffer[i] = _rl_to_upper (rl_line_buffer[i]);
1296 /* Move point to on top of the last character changed. */
1297 rl_point = (direction == 1) ? end - 1 : start;
1302 @node Readline Signal Handling
1303 @section Readline Signal Handling
1305 Signals are asynchronous events sent to a process by the Unix kernel,
1306 sometimes on behalf of another process. They are intended to indicate
1307 exceptional events, like a user pressing the interrupt key on his terminal,
1308 or a network connection being broken. There is a class of signals that can
1309 be sent to the process currently reading input from the keyboard. Since
1310 Readline changes the terminal attributes when it is called, it needs to
1311 perform special processing when such a signal is received in order to
1312 restore the terminal to a sane state, or provide application writers with
1313 functions to do so manually.
1315 Readline contains an internal signal handler that is installed for a
1316 number of signals (@code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM},
1317 @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}).
1318 When one of these signals is received, the signal handler
1319 will reset the terminal attributes to those that were in effect before
1320 @code{readline()} was called, reset the signal handling to what it was
1321 before @code{readline()} was called, and resend the signal to the calling
1323 If and when the calling application's signal handler returns, Readline
1324 will reinitialize the terminal and continue to accept input.
1325 When a @code{SIGINT} is received, the Readline signal handler performs
1326 some additional work, which will cause any partially-entered line to be
1327 aborted (see the description of @code{rl_free_line_state()} below).
1329 There is an additional Readline signal handler, for @code{SIGWINCH}, which
1330 the kernel sends to a process whenever the terminal's size changes (for
1331 example, if a user resizes an @code{xterm}). The Readline @code{SIGWINCH}
1332 handler updates Readline's internal screen size information, and then calls
1333 any @code{SIGWINCH} signal handler the calling application has installed.
1334 Readline calls the application's @code{SIGWINCH} signal handler without
1335 resetting the terminal to its original state. If the application's signal
1336 handler does more than update its idea of the terminal size and return (for
1337 example, a @code{longjmp} back to a main processing loop), it @emph{must}
1338 call @code{rl_cleanup_after_signal()} (described below), to restore the
1341 Readline provides two variables that allow application writers to
1342 control whether or not it will catch certain signals and act on them
1343 when they are received. It is important that applications change the
1344 values of these variables only when calling @code{readline()}, not in
1345 a signal handler, so Readline's internal signal state is not corrupted.
1347 @deftypevar int rl_catch_signals
1348 If this variable is non-zero, Readline will install signal handlers for
1349 @code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, @code{SIGALRM},
1350 @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}.
1352 The default value of @code{rl_catch_signals} is 1.
1355 @deftypevar int rl_catch_sigwinch
1356 If this variable is non-zero, Readline will install a signal handler for
1359 The default value of @code{rl_catch_sigwinch} is 1.
1362 If an application does not wish to have Readline catch any signals, or
1363 to handle signals other than those Readline catches (@code{SIGHUP},
1365 Readline provides convenience functions to do the necessary terminal
1366 and internal state cleanup upon receipt of a signal.
1368 @deftypefun void rl_cleanup_after_signal (void)
1369 This function will reset the state of the terminal to what it was before
1370 @code{readline()} was called, and remove the Readline signal handlers for
1371 all signals, depending on the values of @code{rl_catch_signals} and
1372 @code{rl_catch_sigwinch}.
1375 @deftypefun void rl_free_line_state (void)
1376 This will free any partial state associated with the current input line
1377 (undo information, any partial history entry, any partially-entered
1378 keyboard macro, and any partially-entered numeric argument). This
1379 should be called before @code{rl_cleanup_after_signal()}. The
1380 Readline signal handler for @code{SIGINT} calls this to abort the
1384 @deftypefun void rl_reset_after_signal (void)
1385 This will reinitialize the terminal and reinstall any Readline signal
1386 handlers, depending on the values of @code{rl_catch_signals} and
1387 @code{rl_catch_sigwinch}.
1390 If an application does not wish Readline to catch @code{SIGWINCH}, it may
1391 call @code{rl_resize_terminal()} or @code{rl_set_screen_size()} to force
1392 Readline to update its idea of the terminal size when a @code{SIGWINCH}
1395 @deftypefun void rl_resize_terminal (void)
1396 Update Readline's internal screen size by reading values from the kernel.
1399 @deftypefun void rl_set_screen_size (int rows, int cols)
1400 Set Readline's idea of the terminal size to @var{rows} rows and
1401 @var{cols} columns. If either @var{rows} or @var{columns} is less than
1402 or equal to 0, Readline's idea of that terminal dimension is unchanged.
1405 If an application does not want to install a @code{SIGWINCH} handler, but
1406 is still interested in the screen dimensions, Readline's idea of the screen
1407 size may be queried.
1409 @deftypefun void rl_get_screen_size (int *rows, int *cols)
1410 Return Readline's idea of the terminal's size in the
1411 variables pointed to by the arguments.
1414 @deftypefun void rl_reset_screen_size (void)
1415 Cause Readline to reobtain the screen size and recalculate its dimensions.
1418 The following functions install and remove Readline's signal handlers.
1420 @deftypefun int rl_set_signals (void)
1421 Install Readline's signal handler for @code{SIGINT}, @code{SIGQUIT},
1422 @code{SIGTERM}, @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN},
1423 @code{SIGTTOU}, and @code{SIGWINCH}, depending on the values of
1424 @code{rl_catch_signals} and @code{rl_catch_sigwinch}.
1427 @deftypefun int rl_clear_signals (void)
1428 Remove all of the Readline signal handlers installed by
1429 @code{rl_set_signals()}.
1432 @node Custom Completers
1433 @section Custom Completers
1434 @cindex application-specific completion functions
1436 Typically, a program that reads commands from the user has a way of
1437 disambiguating commands and data. If your program is one of these, then
1438 it can provide completion for commands, data, or both.
1439 The following sections describe how your program and Readline
1440 cooperate to provide this service.
1443 * How Completing Works:: The logic used to do completion.
1444 * Completion Functions:: Functions provided by Readline.
1445 * Completion Variables:: Variables which control completion.
1446 * A Short Completion Example:: An example of writing completer subroutines.
1449 @node How Completing Works
1450 @subsection How Completing Works
1452 In order to complete some text, the full list of possible completions
1453 must be available. That is, it is not possible to accurately
1454 expand a partial word without knowing all of the possible words
1455 which make sense in that context. The Readline library provides
1456 the user interface to completion, and two of the most common
1457 completion functions: filename and username. For completing other types
1458 of text, you must write your own completion function. This section
1459 describes exactly what such functions must do, and provides an example.
1461 There are three major functions used to perform completion:
1465 The user-interface function @code{rl_complete()}. This function is
1466 called with the same arguments as other bindable Readline functions:
1467 @var{count} and @var{invoking_key}.
1468 It isolates the word to be completed and calls
1469 @code{rl_completion_matches()} to generate a list of possible completions.
1470 It then either lists the possible completions, inserts the possible
1471 completions, or actually performs the
1472 completion, depending on which behavior is desired.
1475 The internal function @code{rl_completion_matches()} uses an
1476 application-supplied @dfn{generator} function to generate the list of
1477 possible matches, and then returns the array of these matches.
1478 The caller should place the address of its generator function in
1479 @code{rl_completion_entry_function}.
1482 The generator function is called repeatedly from
1483 @code{rl_completion_matches()}, returning a string each time. The
1484 arguments to the generator function are @var{text} and @var{state}.
1485 @var{text} is the partial word to be completed. @var{state} is zero the
1486 first time the function is called, allowing the generator to perform
1487 any necessary initialization, and a positive non-zero integer for
1488 each subsequent call. The generator function returns
1489 @code{(char *)NULL} to inform @code{rl_completion_matches()} that there are
1490 no more possibilities left. Usually the generator function computes the
1491 list of possible completions when @var{state} is zero, and returns them
1492 one at a time on subsequent calls. Each string the generator function
1493 returns as a match must be allocated with @code{malloc()}; Readline
1494 frees the strings when it has finished with them.
1495 Such a generator function is referred to as an
1496 @dfn{application-specific completion function}.
1500 @deftypefun int rl_complete (int ignore, int invoking_key)
1501 Complete the word at or before point. You have supplied the function
1502 that does the initial simple matching selection algorithm (see
1503 @code{rl_completion_matches()}). The default is to do filename completion.
1506 @deftypevar {rl_compentry_func_t *} rl_completion_entry_function
1507 This is a pointer to the generator function for
1508 @code{rl_completion_matches()}.
1509 If the value of @code{rl_completion_entry_function} is
1510 @code{NULL} then the default filename generator
1511 function, @code{rl_filename_completion_function()}, is used.
1512 An @dfn{application-specific completion function} is a function whose
1513 address is assigned to @code{rl_completion_entry_function} and whose
1514 return values are used to generate possible completions.
1517 @node Completion Functions
1518 @subsection Completion Functions
1520 Here is the complete list of callable completion functions present in
1523 @deftypefun int rl_complete_internal (int what_to_do)
1524 Complete the word at or before point. @var{what_to_do} says what to do
1525 with the completion. A value of @samp{?} means list the possible
1526 completions. @samp{TAB} means do standard completion. @samp{*} means
1527 insert all of the possible completions. @samp{!} means to display
1528 all of the possible completions, if there is more than one, as well as
1529 performing partial completion. @samp{@@} is similar to @samp{!}, but
1530 possible completions are not listed if the possible completions share
1534 @deftypefun int rl_complete (int ignore, int invoking_key)
1535 Complete the word at or before point. You have supplied the function
1536 that does the initial simple matching selection algorithm (see
1537 @code{rl_completion_matches()} and @code{rl_completion_entry_function}).
1538 The default is to do filename
1539 completion. This calls @code{rl_complete_internal()} with an
1540 argument depending on @var{invoking_key}.
1543 @deftypefun int rl_possible_completions (int count, int invoking_key)
1544 List the possible completions. See description of @code{rl_complete
1545 ()}. This calls @code{rl_complete_internal()} with an argument of
1549 @deftypefun int rl_insert_completions (int count, int invoking_key)
1550 Insert the list of possible completions into the line, deleting the
1551 partially-completed word. See description of @code{rl_complete()}.
1552 This calls @code{rl_complete_internal()} with an argument of @samp{*}.
1555 @deftypefun int rl_completion_mode (rl_command_func_t *cfunc)
1556 Returns the apppriate value to pass to @code{rl_complete_internal()}
1557 depending on whether @var{cfunc} was called twice in succession and
1558 the values of the @code{show-all-if-ambiguous} and
1559 @code{show-all-if-unmodified} variables.
1560 Application-specific completion functions may use this function to present
1561 the same interface as @code{rl_complete()}.
1564 @deftypefun {char **} rl_completion_matches (const char *text, rl_compentry_func_t *entry_func)
1565 Returns an array of strings which is a list of completions for
1566 @var{text}. If there are no completions, returns @code{NULL}.
1567 The first entry in the returned array is the substitution for @var{text}.
1568 The remaining entries are the possible completions. The array is
1569 terminated with a @code{NULL} pointer.
1571 @var{entry_func} is a function of two args, and returns a
1572 @code{char *}. The first argument is @var{text}. The second is a
1573 state argument; it is zero on the first call, and non-zero on subsequent
1574 calls. @var{entry_func} returns a @code{NULL} pointer to the caller
1575 when there are no more matches.
1578 @deftypefun {char *} rl_filename_completion_function (const char *text, int state)
1579 A generator function for filename completion in the general case.
1580 @var{text} is a partial filename.
1581 The Bash source is a useful reference for writing application-specific
1582 completion functions (the Bash completion functions call this and other
1583 Readline functions).
1586 @deftypefun {char *} rl_username_completion_function (const char *text, int state)
1587 A completion generator for usernames. @var{text} contains a partial
1588 username preceded by a random character (usually @samp{~}). As with all
1589 completion generators, @var{state} is zero on the first call and non-zero
1590 for subsequent calls.
1593 @node Completion Variables
1594 @subsection Completion Variables
1596 @deftypevar {rl_compentry_func_t *} rl_completion_entry_function
1597 A pointer to the generator function for @code{rl_completion_matches()}.
1598 @code{NULL} means to use @code{rl_filename_completion_function()},
1599 the default filename completer.
1602 @deftypevar {rl_completion_func_t *} rl_attempted_completion_function
1603 A pointer to an alternative function to create matches.
1604 The function is called with @var{text}, @var{start}, and @var{end}.
1605 @var{start} and @var{end} are indices in @code{rl_line_buffer} defining
1606 the boundaries of @var{text}, which is a character string.
1607 If this function exists and returns @code{NULL}, or if this variable is
1608 set to @code{NULL}, then @code{rl_complete()} will call the value of
1609 @code{rl_completion_entry_function} to generate matches, otherwise the
1610 array of strings returned will be used.
1611 If this function sets the @code{rl_attempted_completion_over}
1612 variable to a non-zero value, Readline will not perform its default
1613 completion even if this function returns no matches.
1616 @deftypevar {rl_quote_func_t *} rl_filename_quoting_function
1617 A pointer to a function that will quote a filename in an
1618 application-specific fashion. This is called if filename completion is being
1619 attempted and one of the characters in @code{rl_filename_quote_characters}
1620 appears in a completed filename. The function is called with
1621 @var{text}, @var{match_type}, and @var{quote_pointer}. The @var{text}
1622 is the filename to be quoted. The @var{match_type} is either
1623 @code{SINGLE_MATCH}, if there is only one completion match, or
1624 @code{MULT_MATCH}. Some functions use this to decide whether or not to
1625 insert a closing quote character. The @var{quote_pointer} is a pointer
1626 to any opening quote character the user typed. Some functions choose
1627 to reset this character.
1630 @deftypevar {rl_dequote_func_t *} rl_filename_dequoting_function
1631 A pointer to a function that will remove application-specific quoting
1632 characters from a filename before completion is attempted, so those
1633 characters do not interfere with matching the text against names in
1634 the filesystem. It is called with @var{text}, the text of the word
1635 to be dequoted, and @var{quote_char}, which is the quoting character
1636 that delimits the filename (usually @samp{'} or @samp{"}). If
1637 @var{quote_char} is zero, the filename was not in an embedded string.
1640 @deftypevar {rl_linebuf_func_t *} rl_char_is_quoted_p
1641 A pointer to a function to call that determines whether or not a specific
1642 character in the line buffer is quoted, according to whatever quoting
1643 mechanism the program calling Readline uses. The function is called with
1644 two arguments: @var{text}, the text of the line, and @var{index}, the
1645 index of the character in the line. It is used to decide whether a
1646 character found in @code{rl_completer_word_break_characters} should be
1647 used to break words for the completer.
1650 @deftypevar {rl_compignore_func_t *} rl_ignore_some_completions_function
1651 This function, if defined, is called by the completer when real filename
1652 completion is done, after all the matching names have been generated.
1653 It is passed a @code{NULL} terminated array of matches.
1654 The first element (@code{matches[0]}) is the
1655 maximal substring common to all matches. This function can
1656 re-arrange the list of matches as required, but each element deleted
1657 from the array must be freed.
1660 @deftypevar {rl_icppfunc_t *} rl_directory_completion_hook
1661 This function, if defined, is allowed to modify the directory portion
1662 of filenames Readline completes. It is called with the address of a
1663 string (the current directory name) as an argument, and may modify that string.
1664 If the string is replaced with a new string, the old value should be freed.
1665 Any modified directory name should have a trailing slash.
1666 The modified value will be displayed as part of the completion, replacing
1667 the directory portion of the pathname the user typed.
1668 It returns an integer that should be non-zero if the function modifies
1669 its directory argument.
1670 It could be used to expand symbolic links or shell variables in pathnames.
1673 @deftypevar {rl_compdisp_func_t *} rl_completion_display_matches_hook
1674 If non-zero, then this is the address of a function to call when
1675 completing a word would normally display the list of possible matches.
1676 This function is called in lieu of Readline displaying the list.
1677 It takes three arguments:
1678 (@code{char **}@var{matches}, @code{int} @var{num_matches}, @code{int} @var{max_length})
1679 where @var{matches} is the array of matching strings,
1680 @var{num_matches} is the number of strings in that array, and
1681 @var{max_length} is the length of the longest string in that array.
1682 Readline provides a convenience function, @code{rl_display_match_list},
1683 that takes care of doing the display to Readline's output stream. That
1684 function may be called from this hook.
1687 @deftypevar {const char *} rl_basic_word_break_characters
1688 The basic list of characters that signal a break between words for the
1689 completer routine. The default value of this variable is the characters
1690 which break words for completion in Bash:
1691 @code{" \t\n\"\\'`@@$><=;|&@{("}.
1694 @deftypevar {const char *} rl_basic_quote_characters
1695 A list of quote characters which can cause a word break.
1698 @deftypevar {const char *} rl_completer_word_break_characters
1699 The list of characters that signal a break between words for
1700 @code{rl_complete_internal()}. The default list is the value of
1701 @code{rl_basic_word_break_characters}.
1704 @deftypevar {rl_cpvfunc_t *} rl_completion_word_break_hook
1705 If non-zero, this is the address of a function to call when Readline is
1706 deciding where to separate words for word completion. It should return
1707 a character string like @code{rl_completer_word_break_characters} to be
1708 used to perform the current completion. The function may choose to set
1709 @code{rl_completer_word_break_characters} itself. If the function
1710 returns @code{NULL}, @code{rl_completer_word_break_characters} is used.
1713 @deftypevar {const char *} rl_completer_quote_characters
1714 A list of characters which can be used to quote a substring of the line.
1715 Completion occurs on the entire substring, and within the substring
1716 @code{rl_completer_word_break_characters} are treated as any other character,
1717 unless they also appear within this list.
1720 @deftypevar {const char *} rl_filename_quote_characters
1721 A list of characters that cause a filename to be quoted by the completer
1722 when they appear in a completed filename. The default is the null string.
1725 @deftypevar {const char *} rl_special_prefixes
1726 The list of characters that are word break characters, but should be
1727 left in @var{text} when it is passed to the completion function.
1728 Programs can use this to help determine what kind of completing to do.
1729 For instance, Bash sets this variable to "$@@" so that it can complete
1730 shell variables and hostnames.
1733 @deftypevar int rl_completion_query_items
1734 Up to this many items will be displayed in response to a
1735 possible-completions call. After that, readline asks the user if she is sure
1736 she wants to see them all. The default value is 100. A negative value
1737 indicates that Readline should never ask the user.
1740 @deftypevar {int} rl_completion_append_character
1741 When a single completion alternative matches at the end of the command
1742 line, this character is appended to the inserted completion text. The
1743 default is a space character (@samp{ }). Setting this to the null
1744 character (@samp{\0}) prevents anything being appended automatically.
1745 This can be changed in application-specific completion functions to
1746 provide the ``most sensible word separator character'' according to
1747 an application-specific command line syntax specification.
1750 @deftypevar int rl_completion_suppress_append
1751 If non-zero, @var{rl_completion_append_character} is not appended to
1752 matches at the end of the command line, as described above.
1753 It is set to 0 before any application-specific completion function
1754 is called, and may only be changed within such a function.
1757 @deftypevar int rl_completion_quote_character
1758 When Readline is completing quoted text, as delimited by one of the
1759 characters in @var{rl_completer_quote_characters}, it sets this variable
1760 to the quoting character found.
1761 This is set before any application-specific completion function is called.
1764 @deftypevar int rl_completion_suppress_quote
1765 If non-zero, Readline does not append a matching quote character when
1766 performing completion on a quoted string.
1767 It is set to 0 before any application-specific completion function
1768 is called, and may only be changed within such a function.
1771 @deftypevar int rl_completion_found_quote
1772 When Readline is completing quoted text, it sets this variable
1773 to a non-zero value if the word being completed contains or is delimited
1774 by any quoting characters, including backslashes.
1775 This is set before any application-specific completion function is called.
1778 @deftypevar int rl_completion_mark_symlink_dirs
1779 If non-zero, a slash will be appended to completed filenames that are
1780 symbolic links to directory names, subject to the value of the
1781 user-settable @var{mark-directories} variable.
1782 This variable exists so that application-specific completion functions
1783 can override the user's global preference (set via the
1784 @var{mark-symlinked-directories} Readline variable) if appropriate.
1785 This variable is set to the user's preference before any
1786 application-specific completion function is called, so unless that
1787 function modifies the value, the user's preferences are honored.
1790 @deftypevar int rl_ignore_completion_duplicates
1791 If non-zero, then duplicates in the matches are removed.
1795 @deftypevar int rl_filename_completion_desired
1796 Non-zero means that the results of the matches are to be treated as
1797 filenames. This is @emph{always} zero when completion is attempted,
1798 and can only be changed
1799 within an application-specific completion function. If it is set to a
1800 non-zero value by such a function, directory names have a slash appended
1801 and Readline attempts to quote completed filenames if they contain any
1802 characters in @code{rl_filename_quote_characters} and
1803 @code{rl_filename_quoting_desired} is set to a non-zero value.
1806 @deftypevar int rl_filename_quoting_desired
1807 Non-zero means that the results of the matches are to be quoted using
1808 double quotes (or an application-specific quoting mechanism) if the
1809 completed filename contains any characters in
1810 @code{rl_filename_quote_chars}. This is @emph{always} non-zero
1811 when completion is attempted, and can only be changed within an
1812 application-specific completion function.
1813 The quoting is effected via a call to the function pointed to
1814 by @code{rl_filename_quoting_function}.
1817 @deftypevar int rl_attempted_completion_over
1818 If an application-specific completion function assigned to
1819 @code{rl_attempted_completion_function} sets this variable to a non-zero
1820 value, Readline will not perform its default filename completion even
1821 if the application's completion function returns no matches.
1822 It should be set only by an application's completion function.
1825 @deftypevar int rl_completion_type
1826 Set to a character describing the type of completion Readline is currently
1827 attempting; see the description of @code{rl_complete_internal()}
1828 (@pxref{Completion Functions}) for the list of characters.
1829 This is set to the appropriate value before any application-specific
1830 completion function is called, allowing such functions to present
1831 the same interface as @code{rl_complete()}.
1834 @deftypevar int rl_inhibit_completion
1835 If this variable is non-zero, completion is inhibited. The completion
1836 character will be inserted as any other bound to @code{self-insert}.
1839 @node A Short Completion Example
1840 @subsection A Short Completion Example
1842 Here is a small application demonstrating the use of the GNU Readline
1843 library. It is called @code{fileman}, and the source code resides in
1844 @file{examples/fileman.c}. This sample application provides
1845 completion of command names, line editing features, and access to the
1850 /* fileman.c -- A tiny application which demonstrates how to use the
1851 GNU Readline library. This application interactively allows users
1852 to manipulate files and their modes. */
1855 #include <sys/types.h>
1856 #include <sys/file.h>
1857 #include <sys/stat.h>
1858 #include <sys/errno.h>
1860 #include <readline/readline.h>
1861 #include <readline/history.h>
1863 extern char *xmalloc ();
1865 /* The names of functions that actually do the manipulation. */
1866 int com_list __P((char *));
1867 int com_view __P((char *));
1868 int com_rename __P((char *));
1869 int com_stat __P((char *));
1870 int com_pwd __P((char *));
1871 int com_delete __P((char *));
1872 int com_help __P((char *));
1873 int com_cd __P((char *));
1874 int com_quit __P((char *));
1876 /* A structure which contains information on the commands this program
1880 char *name; /* User printable name of the function. */
1881 rl_icpfunc_t *func; /* Function to call to do the job. */
1882 char *doc; /* Documentation for this function. */
1885 COMMAND commands[] = @{
1886 @{ "cd", com_cd, "Change to directory DIR" @},
1887 @{ "delete", com_delete, "Delete FILE" @},
1888 @{ "help", com_help, "Display this text" @},
1889 @{ "?", com_help, "Synonym for `help'" @},
1890 @{ "list", com_list, "List files in DIR" @},
1891 @{ "ls", com_list, "Synonym for `list'" @},
1892 @{ "pwd", com_pwd, "Print the current working directory" @},
1893 @{ "quit", com_quit, "Quit using Fileman" @},
1894 @{ "rename", com_rename, "Rename FILE to NEWNAME" @},
1895 @{ "stat", com_stat, "Print out statistics on FILE" @},
1896 @{ "view", com_view, "View the contents of FILE" @},
1897 @{ (char *)NULL, (rl_icpfunc_t *)NULL, (char *)NULL @}
1900 /* Forward declarations. */
1901 char *stripwhite ();
1902 COMMAND *find_command ();
1904 /* The name of this program, as taken from argv[0]. */
1907 /* When non-zero, this means the user is done using this program. */
1916 r = xmalloc (strlen (s) + 1);
1929 initialize_readline (); /* Bind our completer. */
1931 /* Loop reading and executing lines until the user quits. */
1932 for ( ; done == 0; )
1934 line = readline ("FileMan: ");
1939 /* Remove leading and trailing whitespace from the line.
1940 Then, if there is anything left, add it to the history list
1942 s = stripwhite (line);
1955 /* Execute a command line. */
1964 /* Isolate the command word. */
1966 while (line[i] && whitespace (line[i]))
1970 while (line[i] && !whitespace (line[i]))
1976 command = find_command (word);
1980 fprintf (stderr, "%s: No such command for FileMan.\n", word);
1984 /* Get argument to command, if any. */
1985 while (whitespace (line[i]))
1990 /* Call the function. */
1991 return ((*(command->func)) (word));
1994 /* Look up NAME as the name of a command, and return a pointer to that
1995 command. Return a NULL pointer if NAME isn't a command name. */
2002 for (i = 0; commands[i].name; i++)
2003 if (strcmp (name, commands[i].name) == 0)
2004 return (&commands[i]);
2006 return ((COMMAND *)NULL);
2009 /* Strip whitespace from the start and end of STRING. Return a pointer
2015 register char *s, *t;
2017 for (s = string; whitespace (*s); s++)
2023 t = s + strlen (s) - 1;
2024 while (t > s && whitespace (*t))
2031 /* **************************************************************** */
2033 /* Interface to Readline Completion */
2035 /* **************************************************************** */
2037 char *command_generator __P((const char *, int));
2038 char **fileman_completion __P((const char *, int, int));
2040 /* Tell the GNU Readline library how to complete. We want to try to
2041 complete on command names if this is the first word in the line, or
2042 on filenames if not. */
2043 initialize_readline ()
2045 /* Allow conditional parsing of the ~/.inputrc file. */
2046 rl_readline_name = "FileMan";
2048 /* Tell the completer that we want a crack first. */
2049 rl_attempted_completion_function = fileman_completion;
2052 /* Attempt to complete on the contents of TEXT. START and END
2053 bound the region of rl_line_buffer that contains the word to
2054 complete. TEXT is the word to complete. We can use the entire
2055 contents of rl_line_buffer in case we want to do some simple
2056 parsing. Returnthe array of matches, or NULL if there aren't any. */
2058 fileman_completion (text, start, end)
2064 matches = (char **)NULL;
2066 /* If this word is at the start of the line, then it is a command
2067 to complete. Otherwise it is the name of a file in the current
2070 matches = rl_completion_matches (text, command_generator);
2075 /* Generator function for command completion. STATE lets us
2076 know whether to start from scratch; without any state
2077 (i.e. STATE == 0), then we start at the top of the list. */
2079 command_generator (text, state)
2083 static int list_index, len;
2086 /* If this is a new word to complete, initialize now. This
2087 includes saving the length of TEXT for efficiency, and
2088 initializing the index variable to 0. */
2092 len = strlen (text);
2095 /* Return the next name which partially matches from the
2097 while (name = commands[list_index].name)
2101 if (strncmp (name, text, len) == 0)
2102 return (dupstr(name));
2105 /* If no names matched, then return NULL. */
2106 return ((char *)NULL);
2109 /* **************************************************************** */
2111 /* FileMan Commands */
2113 /* **************************************************************** */
2115 /* String to pass to system (). This is for the LIST, VIEW and RENAME
2117 static char syscom[1024];
2119 /* List the file(s) named in arg. */
2126 sprintf (syscom, "ls -FClg %s", arg);
2127 return (system (syscom));
2133 if (!valid_argument ("view", arg))
2136 sprintf (syscom, "more %s", arg);
2137 return (system (syscom));
2143 too_dangerous ("rename");
2152 if (!valid_argument ("stat", arg))
2155 if (stat (arg, &finfo) == -1)
2161 printf ("Statistics for `%s':\n", arg);
2163 printf ("%s has %d link%s, and is %d byte%s in length.\n", arg,
2165 (finfo.st_nlink == 1) ? "" : "s",
2167 (finfo.st_size == 1) ? "" : "s");
2168 printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime));
2169 printf (" Last access at: %s", ctime (&finfo.st_atime));
2170 printf (" Last modified at: %s", ctime (&finfo.st_mtime));
2177 too_dangerous ("delete");
2181 /* Print out help for ARG, or for all of the commands if ARG is
2189 for (i = 0; commands[i].name; i++)
2191 if (!*arg || (strcmp (arg, commands[i].name) == 0))
2193 printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc);
2200 printf ("No commands match `%s'. Possibilties are:\n", arg);
2202 for (i = 0; commands[i].name; i++)
2204 /* Print in six columns. */
2211 printf ("%s\t", commands[i].name);
2221 /* Change to the directory ARG. */
2225 if (chdir (arg) == -1)
2235 /* Print out the current working directory. */
2241 s = getcwd (dir, sizeof(dir) - 1);
2244 printf ("Error getting pwd: %s\n", dir);
2248 printf ("Current directory is %s\n", dir);
2252 /* The user wishes to quit using this program. Just set DONE
2261 /* Function which tells you that you can't do this. */
2262 too_dangerous (caller)
2266 "%s: Too dangerous for me to distribute.\n",
2268 fprintf (stderr, "Write it yourself.\n");
2271 /* Return non-zero if ARG is a valid argument for CALLER,
2272 else print an error message and return zero. */
2274 valid_argument (caller, arg)
2279 fprintf (stderr, "%s: Argument required.\n", caller);