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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.) | |
4 | @setchapternewpage odd | |
5 | ||
6 | @ifinfo | |
7 | This document describes the GNU Readline Library, a utility for aiding | |
8 | in the consitency of user interface across discrete programs that need | |
9 | to provide a command line interface. | |
10 | ||
c862e87b | 11 | Copyright (C) 1988, 1994, 1996, 1998, 1999 Free Software Foundation, Inc. |
d60d9f65 SS |
12 | |
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. | |
16 | ||
17 | @ignore | |
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). | |
22 | @end ignore | |
23 | ||
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. | |
28 | ||
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 | |
32 | by the Foundation. | |
33 | @end ifinfo | |
34 | ||
35 | @node Programming with GNU Readline | |
36 | @chapter Programming with GNU Readline | |
37 | ||
38 | This chapter describes the interface between the GNU Readline Library and | |
39 | other programs. If you are a programmer, and you wish to include the | |
40 | features found in GNU Readline | |
41 | such as completion, line editing, and interactive history manipulation | |
42 | in your own programs, this section is for you. | |
43 | ||
44 | @menu | |
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 | |
48 | functions. | |
49 | * Readline Convenience Functions:: Functions which Readline supplies to | |
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50 | aid in writing your own custom |
51 | functions. | |
52 | * Readline Signal Handling:: How Readline behaves when it receives signals. | |
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53 | * Custom Completers:: Supplanting or supplementing Readline's |
54 | completion functions. | |
55 | @end menu | |
56 | ||
57 | @node Basic Behavior | |
58 | @section Basic Behavior | |
59 | ||
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 ()}. | |
65 | ||
66 | @findex readline | |
67 | @cindex readline, function | |
68 | The function @code{readline ()} prints a prompt and then reads and returns | |
69 | a single line of text from the user. The line @code{readline} | |
70 | returns is allocated with @code{malloc ()}; you should @code{free ()} | |
71 | the line when you are done with it. The declaration for @code{readline} | |
72 | in ANSI C is | |
73 | ||
74 | @example | |
75 | @code{char *readline (char *@var{prompt});} | |
76 | @end example | |
77 | ||
78 | @noindent | |
79 | So, one might say | |
80 | @example | |
81 | @code{char *line = readline ("Enter a line: ");} | |
82 | @end example | |
83 | @noindent | |
84 | in order to read a line of text from the user. | |
85 | The line returned has the final newline removed, so only the | |
86 | text remains. | |
87 | ||
88 | If @code{readline} encounters an @code{EOF} while reading the line, and the | |
89 | line is empty at that point, then @code{(char *)NULL} is returned. | |
90 | Otherwise, the line is ended just as if a newline had been typed. | |
91 | ||
92 | If you want the user to be able to get at the line later, (with | |
93 | @key{C-p} for example), you must call @code{add_history ()} to save the | |
94 | line away in a @dfn{history} list of such lines. | |
95 | ||
96 | @example | |
97 | @code{add_history (line)}; | |
98 | @end example | |
99 | ||
100 | @noindent | |
101 | For full details on the GNU History Library, see the associated manual. | |
102 | ||
103 | It is preferable to avoid saving empty lines on the history list, since | |
104 | users rarely have a burning need to reuse a blank line. Here is | |
105 | a function which usefully replaces the standard @code{gets ()} library | |
106 | function, and has the advantage of no static buffer to overflow: | |
107 | ||
108 | @example | |
109 | /* A static variable for holding the line. */ | |
110 | static char *line_read = (char *)NULL; | |
111 | ||
112 | /* Read a string, and return a pointer to it. Returns NULL on EOF. */ | |
113 | char * | |
114 | rl_gets () | |
115 | @{ | |
116 | /* If the buffer has already been allocated, return the memory | |
117 | to the free pool. */ | |
118 | if (line_read) | |
119 | @{ | |
120 | free (line_read); | |
121 | line_read = (char *)NULL; | |
122 | @} | |
123 | ||
124 | /* Get a line from the user. */ | |
125 | line_read = readline (""); | |
126 | ||
127 | /* If the line has any text in it, save it on the history. */ | |
128 | if (line_read && *line_read) | |
129 | add_history (line_read); | |
130 | ||
131 | return (line_read); | |
132 | @} | |
133 | @end example | |
134 | ||
135 | This function gives the user the default behaviour of @key{TAB} | |
136 | completion: completion on file names. If you do not want Readline to | |
137 | complete on filenames, you can change the binding of the @key{TAB} key | |
138 | with @code{rl_bind_key ()}. | |
139 | ||
140 | @example | |
141 | @code{int rl_bind_key (int @var{key}, int (*@var{function})());} | |
142 | @end example | |
143 | ||
144 | @code{rl_bind_key ()} takes two arguments: @var{key} is the character that | |
145 | you want to bind, and @var{function} is the address of the function to | |
146 | call when @var{key} is pressed. Binding @key{TAB} to @code{rl_insert ()} | |
147 | makes @key{TAB} insert itself. | |
148 | @code{rl_bind_key ()} returns non-zero if @var{key} is not a valid | |
149 | ASCII character code (between 0 and 255). | |
150 | ||
151 | Thus, to disable the default @key{TAB} behavior, the following suffices: | |
152 | @example | |
153 | @code{rl_bind_key ('\t', rl_insert);} | |
154 | @end example | |
155 | ||
156 | This code should be executed once at the start of your program; you | |
157 | might write a function called @code{initialize_readline ()} which | |
158 | performs this and other desired initializations, such as installing | |
159 | custom completers (@pxref{Custom Completers}). | |
160 | ||
161 | @node Custom Functions | |
162 | @section Custom Functions | |
163 | ||
164 | Readline provides many functions for manipulating the text of | |
165 | the line, but it isn't possible to anticipate the needs of all | |
166 | programs. This section describes the various functions and variables | |
167 | defined within the Readline library which allow a user program to add | |
168 | customized functionality to Readline. | |
169 | ||
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170 | Before declaring any functions that customize Readline's behavior, or |
171 | using any functionality Readline provides in other code, an | |
172 | application writer should include the file @code{<readline/readline.h>} | |
173 | in any file that uses Readline's features. Since some of the definitions | |
174 | in @code{readline.h} use the @code{stdio} library, the file | |
175 | @code{<stdio.h>} should be included before @code{readline.h}. | |
176 | ||
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177 | @menu |
178 | * The Function Type:: C declarations to make code readable. | |
179 | * Function Writing:: Variables and calling conventions. | |
180 | @end menu | |
181 | ||
182 | @node The Function Type | |
183 | @subsection The Function Type | |
184 | ||
185 | For readabilty, we declare a new type of object, called | |
186 | @dfn{Function}. A @code{Function} is a C function which | |
187 | returns an @code{int}. The type declaration for @code{Function} is: | |
188 | ||
189 | @noindent | |
190 | @code{typedef int Function ();} | |
191 | ||
192 | The reason for declaring this new type is to make it easier to write | |
193 | code describing pointers to C functions. Let us say we had a variable | |
194 | called @var{func} which was a pointer to a function. Instead of the | |
195 | classic C declaration | |
196 | ||
197 | @code{int (*)()func;} | |
198 | ||
199 | @noindent | |
200 | we may write | |
201 | ||
202 | @code{Function *func;} | |
203 | ||
204 | @noindent | |
205 | Similarly, there are | |
206 | ||
207 | @example | |
208 | typedef void VFunction (); | |
209 | typedef char *CPFunction (); @r{and} | |
210 | typedef char **CPPFunction (); | |
211 | @end example | |
212 | ||
213 | @noindent | |
214 | for functions returning no value, @code{pointer to char}, and | |
215 | @code{pointer to pointer to char}, respectively. | |
216 | ||
217 | @node Function Writing | |
218 | @subsection Writing a New Function | |
219 | ||
220 | In order to write new functions for Readline, you need to know the | |
221 | calling conventions for keyboard-invoked functions, and the names of the | |
222 | variables that describe the current state of the line read so far. | |
223 | ||
224 | The calling sequence for a command @code{foo} looks like | |
225 | ||
226 | @example | |
227 | @code{foo (int count, int key)} | |
228 | @end example | |
229 | ||
230 | @noindent | |
231 | where @var{count} is the numeric argument (or 1 if defaulted) and | |
232 | @var{key} is the key that invoked this function. | |
233 | ||
234 | It is completely up to the function as to what should be done with the | |
235 | numeric argument. Some functions use it as a repeat count, some | |
236 | as a flag, and others to choose alternate behavior (refreshing the current | |
237 | line as opposed to refreshing the screen, for example). Some choose to | |
238 | ignore it. In general, if a | |
239 | function uses the numeric argument as a repeat count, it should be able | |
240 | to do something useful with both negative and positive arguments. | |
241 | At the very least, it should be aware that it can be passed a | |
242 | negative argument. | |
243 | ||
244 | @node Readline Variables | |
245 | @section Readline Variables | |
246 | ||
247 | These variables are available to function writers. | |
248 | ||
249 | @deftypevar {char *} rl_line_buffer | |
250 | This is the line gathered so far. You are welcome to modify the | |
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251 | contents of the line, but see @ref{Allowing Undoing}. The |
252 | function @code{rl_extend_line_buffer} is available to increase | |
253 | the memory allocated to @code{rl_line_buffer}. | |
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254 | @end deftypevar |
255 | ||
256 | @deftypevar int rl_point | |
257 | The offset of the current cursor position in @code{rl_line_buffer} | |
258 | (the @emph{point}). | |
259 | @end deftypevar | |
260 | ||
261 | @deftypevar int rl_end | |
262 | The number of characters present in @code{rl_line_buffer}. When | |
263 | @code{rl_point} is at the end of the line, @code{rl_point} and | |
264 | @code{rl_end} are equal. | |
265 | @end deftypevar | |
266 | ||
267 | @deftypevar int rl_mark | |
268 | The mark (saved position) in the current line. If set, the mark | |
269 | and point define a @emph{region}. | |
270 | @end deftypevar | |
271 | ||
272 | @deftypevar int rl_done | |
273 | Setting this to a non-zero value causes Readline to return the current | |
274 | line immediately. | |
275 | @end deftypevar | |
276 | ||
277 | @deftypevar int rl_pending_input | |
278 | Setting this to a value makes it the next keystroke read. This is a | |
279 | way to stuff a single character into the input stream. | |
280 | @end deftypevar | |
281 | ||
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282 | @deftypevar int rl_erase_empty_line |
283 | Setting this to a non-zero value causes Readline to completely erase | |
284 | the current line, including any prompt, any time a newline is typed as | |
285 | the only character on an otherwise-empty line. The cursor is moved to | |
286 | the beginning of the newly-blank line. | |
287 | @end deftypevar | |
288 | ||
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289 | @deftypevar {char *} rl_prompt |
290 | The prompt Readline uses. This is set from the argument to | |
291 | @code{readline ()}, and should not be assigned to directly. | |
292 | @end deftypevar | |
293 | ||
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294 | @deftypevar int rl_already_prompted |
295 | If an application wishes to display the prompt itself, rather than have | |
296 | Readline do it the first time @code{readline()} is called, it should set | |
297 | this variable to a non-zero value after displaying the prompt. | |
298 | The prompt must also be passed as the argument to @code{readline()} so | |
299 | the redisplay functions can update the display properly. | |
300 | The calling application is responsible for managing the value; Readline | |
301 | never sets it. | |
302 | @end deftypevar | |
303 | ||
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304 | @deftypevar {char *} rl_library_version |
305 | The version number of this revision of the library. | |
306 | @end deftypevar | |
307 | ||
308 | @deftypevar {char *} rl_terminal_name | |
309 | The terminal type, used for initialization. | |
310 | @end deftypevar | |
311 | ||
312 | @deftypevar {char *} rl_readline_name | |
313 | This variable is set to a unique name by each application using Readline. | |
314 | The value allows conditional parsing of the inputrc file | |
315 | (@pxref{Conditional Init Constructs}). | |
316 | @end deftypevar | |
317 | ||
318 | @deftypevar {FILE *} rl_instream | |
319 | The stdio stream from which Readline reads input. | |
320 | @end deftypevar | |
321 | ||
322 | @deftypevar {FILE *} rl_outstream | |
323 | The stdio stream to which Readline performs output. | |
324 | @end deftypevar | |
325 | ||
326 | @deftypevar {Function *} rl_startup_hook | |
327 | If non-zero, this is the address of a function to call just | |
328 | before @code{readline} prints the first prompt. | |
329 | @end deftypevar | |
330 | ||
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331 | @deftypevar {Function *} rl_pre_input_hook |
332 | If non-zero, this is the address of a function to call after | |
333 | the first prompt has been printed and just before @code{readline} | |
334 | starts reading input characters. | |
335 | @end deftypevar | |
336 | ||
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337 | @deftypevar {Function *} rl_event_hook |
338 | If non-zero, this is the address of a function to call periodically | |
339 | when readline is waiting for terminal input. | |
340 | @end deftypevar | |
341 | ||
342 | @deftypevar {Function *} rl_getc_function | |
343 | If non-zero, @code{readline} will call indirectly through this pointer | |
344 | to get a character from the input stream. By default, it is set to | |
345 | @code{rl_getc}, the default @code{readline} character input function | |
346 | (@pxref{Utility Functions}). | |
347 | @end deftypevar | |
348 | ||
349 | @deftypevar {VFunction *} rl_redisplay_function | |
350 | If non-zero, @code{readline} will call indirectly through this pointer | |
351 | to update the display with the current contents of the editing buffer. | |
352 | By default, it is set to @code{rl_redisplay}, the default @code{readline} | |
353 | redisplay function (@pxref{Redisplay}). | |
354 | @end deftypevar | |
355 | ||
356 | @deftypevar {Keymap} rl_executing_keymap | |
357 | This variable is set to the keymap (@pxref{Keymaps}) in which the | |
358 | currently executing readline function was found. | |
359 | @end deftypevar | |
360 | ||
361 | @deftypevar {Keymap} rl_binding_keymap | |
362 | This variable is set to the keymap (@pxref{Keymaps}) in which the | |
363 | last key binding occurred. | |
364 | @end deftypevar | |
365 | ||
366 | @node Readline Convenience Functions | |
367 | @section Readline Convenience Functions | |
368 | ||
369 | @menu | |
370 | * Function Naming:: How to give a function you write a name. | |
371 | * Keymaps:: Making keymaps. | |
372 | * Binding Keys:: Changing Keymaps. | |
373 | * Associating Function Names and Bindings:: Translate function names to | |
374 | key sequences. | |
375 | * Allowing Undoing:: How to make your functions undoable. | |
376 | * Redisplay:: Functions to control line display. | |
377 | * Modifying Text:: Functions to modify @code{rl_line_buffer}. | |
378 | * Utility Functions:: Generally useful functions and hooks. | |
379 | * Alternate Interface:: Using Readline in a `callback' fashion. | |
380 | @end menu | |
381 | ||
382 | @node Function Naming | |
383 | @subsection Naming a Function | |
384 | ||
385 | The user can dynamically change the bindings of keys while using | |
386 | Readline. This is done by representing the function with a descriptive | |
387 | name. The user is able to type the descriptive name when referring to | |
388 | the function. Thus, in an init file, one might find | |
389 | ||
390 | @example | |
391 | Meta-Rubout: backward-kill-word | |
392 | @end example | |
393 | ||
394 | This binds the keystroke @key{Meta-Rubout} to the function | |
395 | @emph{descriptively} named @code{backward-kill-word}. You, as the | |
396 | programmer, should bind the functions you write to descriptive names as | |
397 | well. Readline provides a function for doing that: | |
398 | ||
399 | @deftypefun int rl_add_defun (char *name, Function *function, int key) | |
400 | Add @var{name} to the list of named functions. Make @var{function} be | |
401 | the function that gets called. If @var{key} is not -1, then bind it to | |
402 | @var{function} using @code{rl_bind_key ()}. | |
403 | @end deftypefun | |
404 | ||
405 | Using this function alone is sufficient for most applications. It is | |
406 | the recommended way to add a few functions to the default functions that | |
407 | Readline has built in. If you need to do something other | |
408 | than adding a function to Readline, you may need to use the | |
409 | underlying functions described below. | |
410 | ||
411 | @node Keymaps | |
412 | @subsection Selecting a Keymap | |
413 | ||
414 | Key bindings take place on a @dfn{keymap}. The keymap is the | |
415 | association between the keys that the user types and the functions that | |
416 | get run. You can make your own keymaps, copy existing keymaps, and tell | |
417 | Readline which keymap to use. | |
418 | ||
419 | @deftypefun Keymap rl_make_bare_keymap () | |
420 | Returns a new, empty keymap. The space for the keymap is allocated with | |
421 | @code{malloc ()}; you should @code{free ()} it when you are done. | |
422 | @end deftypefun | |
423 | ||
424 | @deftypefun Keymap rl_copy_keymap (Keymap map) | |
425 | Return a new keymap which is a copy of @var{map}. | |
426 | @end deftypefun | |
427 | ||
428 | @deftypefun Keymap rl_make_keymap () | |
429 | Return a new keymap with the printing characters bound to rl_insert, | |
430 | the lowercase Meta characters bound to run their equivalents, and | |
431 | the Meta digits bound to produce numeric arguments. | |
432 | @end deftypefun | |
433 | ||
434 | @deftypefun void rl_discard_keymap (Keymap keymap) | |
435 | Free the storage associated with @var{keymap}. | |
436 | @end deftypefun | |
437 | ||
438 | Readline has several internal keymaps. These functions allow you to | |
439 | change which keymap is active. | |
440 | ||
441 | @deftypefun Keymap rl_get_keymap () | |
442 | Returns the currently active keymap. | |
443 | @end deftypefun | |
444 | ||
445 | @deftypefun void rl_set_keymap (Keymap keymap) | |
446 | Makes @var{keymap} the currently active keymap. | |
447 | @end deftypefun | |
448 | ||
449 | @deftypefun Keymap rl_get_keymap_by_name (char *name) | |
450 | Return the keymap matching @var{name}. @var{name} is one which would | |
451 | be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}). | |
452 | @end deftypefun | |
453 | ||
454 | @deftypefun {char *} rl_get_keymap_name (Keymap keymap) | |
455 | Return the name matching @var{keymap}. @var{name} is one which would | |
456 | be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}). | |
457 | @end deftypefun | |
458 | ||
459 | @node Binding Keys | |
460 | @subsection Binding Keys | |
461 | ||
462 | You associate keys with functions through the keymap. Readline has | |
463 | several internal keymaps: @code{emacs_standard_keymap}, | |
464 | @code{emacs_meta_keymap}, @code{emacs_ctlx_keymap}, | |
465 | @code{vi_movement_keymap}, and @code{vi_insertion_keymap}. | |
466 | @code{emacs_standard_keymap} is the default, and the examples in | |
467 | this manual assume that. | |
468 | ||
1b17e766 EZ |
469 | Since @code{readline} installs a set of default key bindings the first |
470 | time it is called, there is always the danger that a custom binding | |
471 | installed before the first call to @code{readline} will be overridden. | |
472 | An alternate mechanism is to install custom key bindings in an | |
473 | initialization function assigned to the @code{rl_startup_hook} variable | |
474 | (@pxref{Readline Variables}). | |
475 | ||
d60d9f65 SS |
476 | These functions manage key bindings. |
477 | ||
478 | @deftypefun int rl_bind_key (int key, Function *function) | |
479 | Binds @var{key} to @var{function} in the currently active keymap. | |
480 | Returns non-zero in the case of an invalid @var{key}. | |
481 | @end deftypefun | |
482 | ||
483 | @deftypefun int rl_bind_key_in_map (int key, Function *function, Keymap map) | |
484 | Bind @var{key} to @var{function} in @var{map}. Returns non-zero in the case | |
485 | of an invalid @var{key}. | |
486 | @end deftypefun | |
487 | ||
488 | @deftypefun int rl_unbind_key (int key) | |
489 | Bind @var{key} to the null function in the currently active keymap. | |
490 | Returns non-zero in case of error. | |
491 | @end deftypefun | |
492 | ||
493 | @deftypefun int rl_unbind_key_in_map (int key, Keymap map) | |
494 | Bind @var{key} to the null function in @var{map}. | |
495 | Returns non-zero in case of error. | |
496 | @end deftypefun | |
497 | ||
498 | @deftypefun int rl_unbind_function_in_map (Function *function, Keymap map) | |
499 | Unbind all keys that execute @var{function} in @var{map}. | |
500 | @end deftypefun | |
501 | ||
502 | @deftypefun int rl_unbind_command_in_map (char *command, Keymap map) | |
503 | Unbind all keys that are bound to @var{command} in @var{map}. | |
504 | @end deftypefun | |
505 | ||
506 | @deftypefun int rl_generic_bind (int type, char *keyseq, char *data, Keymap map) | |
507 | Bind the key sequence represented by the string @var{keyseq} to the arbitrary | |
508 | pointer @var{data}. @var{type} says what kind of data is pointed to by | |
509 | @var{data}; this can be a function (@code{ISFUNC}), a macro | |
510 | (@code{ISMACR}), or a keymap (@code{ISKMAP}). This makes new keymaps as | |
511 | necessary. The initial keymap in which to do bindings is @var{map}. | |
512 | @end deftypefun | |
513 | ||
514 | @deftypefun int rl_parse_and_bind (char *line) | |
515 | Parse @var{line} as if it had been read from the @code{inputrc} file and | |
516 | perform any key bindings and variable assignments found | |
517 | (@pxref{Readline Init File}). | |
518 | @end deftypefun | |
519 | ||
520 | @deftypefun int rl_read_init_file (char *filename) | |
521 | Read keybindings and variable assignments from @var{filename} | |
522 | (@pxref{Readline Init File}). | |
523 | @end deftypefun | |
524 | ||
525 | @node Associating Function Names and Bindings | |
526 | @subsection Associating Function Names and Bindings | |
527 | ||
528 | These functions allow you to find out what keys invoke named functions | |
529 | and the functions invoked by a particular key sequence. | |
530 | ||
531 | @deftypefun {Function *} rl_named_function (char *name) | |
532 | Return the function with name @var{name}. | |
533 | @end deftypefun | |
534 | ||
535 | @deftypefun {Function *} rl_function_of_keyseq (char *keyseq, Keymap map, int *type) | |
536 | Return the function invoked by @var{keyseq} in keymap @var{map}. | |
537 | If @var{map} is NULL, the current keymap is used. If @var{type} is | |
538 | not NULL, the type of the object is returned in it (one of @code{ISFUNC}, | |
539 | @code{ISKMAP}, or @code{ISMACR}). | |
540 | @end deftypefun | |
541 | ||
542 | @deftypefun {char **} rl_invoking_keyseqs (Function *function) | |
543 | Return an array of strings representing the key sequences used to | |
544 | invoke @var{function} in the current keymap. | |
545 | @end deftypefun | |
546 | ||
547 | @deftypefun {char **} rl_invoking_keyseqs_in_map (Function *function, Keymap map) | |
548 | Return an array of strings representing the key sequences used to | |
549 | invoke @var{function} in the keymap @var{map}. | |
550 | @end deftypefun | |
551 | ||
552 | @deftypefun void rl_function_dumper (int readable) | |
553 | Print the readline function names and the key sequences currently | |
554 | bound to them to @code{rl_outstream}. If @var{readable} is non-zero, | |
555 | the list is formatted in such a way that it can be made part of an | |
556 | @code{inputrc} file and re-read. | |
557 | @end deftypefun | |
558 | ||
559 | @deftypefun void rl_list_funmap_names () | |
560 | Print the names of all bindable Readline functions to @code{rl_outstream}. | |
561 | @end deftypefun | |
562 | ||
1b17e766 EZ |
563 | @deftypefun {char **} rl_funmap_names () |
564 | Return a NULL terminated array of known function names. The array is | |
565 | sorted. The array itself is allocated, but not the strings inside. You | |
566 | should free () the array when you done, but not the pointrs. | |
567 | @end deftypefun | |
568 | ||
d60d9f65 SS |
569 | @node Allowing Undoing |
570 | @subsection Allowing Undoing | |
571 | ||
572 | Supporting the undo command is a painless thing, and makes your | |
573 | functions much more useful. It is certainly easy to try | |
574 | something if you know you can undo it. I could use an undo function for | |
575 | the stock market. | |
576 | ||
577 | If your function simply inserts text once, or deletes text once, and | |
578 | uses @code{rl_insert_text ()} or @code{rl_delete_text ()} to do it, then | |
579 | undoing is already done for you automatically. | |
580 | ||
581 | If you do multiple insertions or multiple deletions, or any combination | |
582 | of these operations, you should group them together into one operation. | |
583 | This is done with @code{rl_begin_undo_group ()} and | |
584 | @code{rl_end_undo_group ()}. | |
585 | ||
586 | The types of events that can be undone are: | |
587 | ||
588 | @example | |
589 | enum undo_code @{ UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END @}; | |
590 | @end example | |
591 | ||
592 | Notice that @code{UNDO_DELETE} means to insert some text, and | |
593 | @code{UNDO_INSERT} means to delete some text. That is, the undo code | |
594 | tells undo what to undo, not how to undo it. @code{UNDO_BEGIN} and | |
595 | @code{UNDO_END} are tags added by @code{rl_begin_undo_group ()} and | |
596 | @code{rl_end_undo_group ()}. | |
597 | ||
598 | @deftypefun int rl_begin_undo_group () | |
599 | Begins saving undo information in a group construct. The undo | |
600 | information usually comes from calls to @code{rl_insert_text ()} and | |
601 | @code{rl_delete_text ()}, but could be the result of calls to | |
602 | @code{rl_add_undo ()}. | |
603 | @end deftypefun | |
604 | ||
605 | @deftypefun int rl_end_undo_group () | |
606 | Closes the current undo group started with @code{rl_begin_undo_group | |
607 | ()}. There should be one call to @code{rl_end_undo_group ()} | |
608 | for each call to @code{rl_begin_undo_group ()}. | |
609 | @end deftypefun | |
610 | ||
611 | @deftypefun void rl_add_undo (enum undo_code what, int start, int end, char *text) | |
612 | Remember how to undo an event (according to @var{what}). The affected | |
613 | text runs from @var{start} to @var{end}, and encompasses @var{text}. | |
614 | @end deftypefun | |
615 | ||
616 | @deftypefun void free_undo_list () | |
617 | Free the existing undo list. | |
618 | @end deftypefun | |
619 | ||
620 | @deftypefun int rl_do_undo () | |
621 | Undo the first thing on the undo list. Returns @code{0} if there was | |
622 | nothing to undo, non-zero if something was undone. | |
623 | @end deftypefun | |
624 | ||
625 | Finally, if you neither insert nor delete text, but directly modify the | |
626 | existing text (e.g., change its case), call @code{rl_modifying ()} | |
627 | once, just before you modify the text. You must supply the indices of | |
628 | the text range that you are going to modify. | |
629 | ||
630 | @deftypefun int rl_modifying (int start, int end) | |
631 | Tell Readline to save the text between @var{start} and @var{end} as a | |
632 | single undo unit. It is assumed that you will subsequently modify | |
633 | that text. | |
634 | @end deftypefun | |
635 | ||
636 | @node Redisplay | |
637 | @subsection Redisplay | |
638 | ||
639 | @deftypefun void rl_redisplay () | |
640 | Change what's displayed on the screen to reflect the current contents | |
641 | of @code{rl_line_buffer}. | |
642 | @end deftypefun | |
643 | ||
644 | @deftypefun int rl_forced_update_display () | |
645 | Force the line to be updated and redisplayed, whether or not | |
646 | Readline thinks the screen display is correct. | |
647 | @end deftypefun | |
648 | ||
649 | @deftypefun int rl_on_new_line () | |
1b17e766 | 650 | Tell the update functions that we have moved onto a new (empty) line, |
d60d9f65 SS |
651 | usually after ouputting a newline. |
652 | @end deftypefun | |
653 | ||
1b17e766 EZ |
654 | @deftypefun int rl_on_new_line_with_prompt () |
655 | Tell the update functions that we have moved onto a new line, with | |
656 | @var{rl_prompt} already displayed. | |
657 | This could be used by applications that want to output the prompt string | |
658 | themselves, but still need Readline to know the prompt string length for | |
659 | redisplay. | |
660 | It should be used after setting @var{rl_already_prompted}. | |
661 | @end deftypefun | |
662 | ||
d60d9f65 SS |
663 | @deftypefun int rl_reset_line_state () |
664 | Reset the display state to a clean state and redisplay the current line | |
665 | starting on a new line. | |
666 | @end deftypefun | |
667 | ||
668 | @deftypefun int rl_message (va_alist) | |
669 | The arguments are a string as would be supplied to @code{printf}. The | |
670 | resulting string is displayed in the @dfn{echo area}. The echo area | |
671 | is also used to display numeric arguments and search strings. | |
672 | @end deftypefun | |
673 | ||
674 | @deftypefun int rl_clear_message () | |
675 | Clear the message in the echo area. | |
676 | @end deftypefun | |
677 | ||
c862e87b JM |
678 | @deftypefun void rl_save_prompt () |
679 | Save the local Readline prompt display state in preparation for | |
680 | displaying a new message in the message area with @code{rl_message}. | |
681 | @end deftypefun | |
682 | ||
683 | @deftypefun void rl_restore_prompt () | |
684 | Restore the local Readline prompt display state saved by the most | |
685 | recent call to @code{rl_save_prompt}. | |
686 | @end deftypefun | |
687 | ||
d60d9f65 SS |
688 | @node Modifying Text |
689 | @subsection Modifying Text | |
690 | ||
691 | @deftypefun int rl_insert_text (char *text) | |
692 | Insert @var{text} into the line at the current cursor position. | |
693 | @end deftypefun | |
694 | ||
695 | @deftypefun int rl_delete_text (int start, int end) | |
696 | Delete the text between @var{start} and @var{end} in the current line. | |
697 | @end deftypefun | |
698 | ||
699 | @deftypefun {char *} rl_copy_text (int start, int end) | |
700 | Return a copy of the text between @var{start} and @var{end} in | |
701 | the current line. | |
702 | @end deftypefun | |
703 | ||
704 | @deftypefun int rl_kill_text (int start, int end) | |
705 | Copy the text between @var{start} and @var{end} in the current line | |
706 | to the kill ring, appending or prepending to the last kill if the | |
707 | last command was a kill command. The text is deleted. | |
708 | If @var{start} is less than @var{end}, | |
709 | the text is appended, otherwise prepended. If the last command was | |
710 | not a kill, a new kill ring slot is used. | |
711 | @end deftypefun | |
712 | ||
713 | @node Utility Functions | |
714 | @subsection Utility Functions | |
715 | ||
716 | @deftypefun int rl_read_key () | |
717 | Return the next character available. This handles input inserted into | |
718 | the input stream via @var{pending input} (@pxref{Readline Variables}) | |
719 | and @code{rl_stuff_char ()}, macros, and characters read from the keyboard. | |
720 | @end deftypefun | |
721 | ||
722 | @deftypefun int rl_getc (FILE *) | |
723 | Return the next character available from the keyboard. | |
724 | @end deftypefun | |
725 | ||
726 | @deftypefun int rl_stuff_char (int c) | |
727 | Insert @var{c} into the Readline input stream. It will be "read" | |
728 | before Readline attempts to read characters from the terminal with | |
729 | @code{rl_read_key ()}. | |
730 | @end deftypefun | |
731 | ||
1b17e766 | 732 | @deftypefun int rl_extend_line_buffer (int len) |
d60d9f65 SS |
733 | Ensure that @code{rl_line_buffer} has enough space to hold @var{len} |
734 | characters, possibly reallocating it if necessary. | |
735 | @end deftypefun | |
736 | ||
737 | @deftypefun int rl_initialize () | |
738 | Initialize or re-initialize Readline's internal state. | |
739 | @end deftypefun | |
740 | ||
741 | @deftypefun int rl_reset_terminal (char *terminal_name) | |
742 | Reinitialize Readline's idea of the terminal settings using | |
743 | @var{terminal_name} as the terminal type (e.g., @code{vt100}). | |
1b17e766 EZ |
744 | If @var{terminal_name} is NULL, the value of the @code{TERM} |
745 | environment variable is used. | |
d60d9f65 SS |
746 | @end deftypefun |
747 | ||
748 | @deftypefun int alphabetic (int c) | |
749 | Return 1 if @var{c} is an alphabetic character. | |
750 | @end deftypefun | |
751 | ||
752 | @deftypefun int numeric (int c) | |
753 | Return 1 if @var{c} is a numeric character. | |
754 | @end deftypefun | |
755 | ||
756 | @deftypefun int ding () | |
757 | Ring the terminal bell, obeying the setting of @code{bell-style}. | |
758 | @end deftypefun | |
759 | ||
c862e87b JM |
760 | @deftypefun void rl_display_match_list (char **matches, int len, int max) |
761 | A convenience function for displaying a list of strings in | |
762 | columnar format on Readline's output stream. @code{matches} is the list | |
763 | of strings, in argv format, such as a list of completion matches. | |
764 | @code{len} is the number of strings in @code{matches}, and @code{max} | |
765 | is the length of the longest string in @code{matches}. This function uses | |
766 | the setting of @code{print-completions-horizontally} to select how the | |
767 | matches are displayed (@pxref{Readline Init File Syntax}). | |
768 | @end deftypefun | |
769 | ||
d60d9f65 SS |
770 | The following are implemented as macros, defined in @code{chartypes.h}. |
771 | ||
772 | @deftypefun int uppercase_p (int c) | |
773 | Return 1 if @var{c} is an uppercase alphabetic character. | |
774 | @end deftypefun | |
775 | ||
776 | @deftypefun int lowercase_p (int c) | |
777 | Return 1 if @var{c} is a lowercase alphabetic character. | |
778 | @end deftypefun | |
779 | ||
780 | @deftypefun int digit_p (int c) | |
781 | Return 1 if @var{c} is a numeric character. | |
782 | @end deftypefun | |
783 | ||
784 | @deftypefun int to_upper (int c) | |
785 | If @var{c} is a lowercase alphabetic character, return the corresponding | |
786 | uppercase character. | |
787 | @end deftypefun | |
788 | ||
789 | @deftypefun int to_lower (int c) | |
790 | If @var{c} is an uppercase alphabetic character, return the corresponding | |
791 | lowercase character. | |
792 | @end deftypefun | |
793 | ||
794 | @deftypefun int digit_value (int c) | |
795 | If @var{c} is a number, return the value it represents. | |
796 | @end deftypefun | |
797 | ||
798 | @node Alternate Interface | |
799 | @subsection Alternate Interface | |
800 | ||
801 | An alternate interface is available to plain @code{readline()}. Some | |
802 | applications need to interleave keyboard I/O with file, device, or | |
803 | window system I/O, typically by using a main loop to @code{select()} | |
804 | on various file descriptors. To accomodate this need, readline can | |
805 | also be invoked as a `callback' function from an event loop. There | |
806 | are functions available to make this easy. | |
807 | ||
808 | @deftypefun void rl_callback_handler_install (char *prompt, Vfunction *lhandler) | |
809 | Set up the terminal for readline I/O and display the initial | |
810 | expanded value of @var{prompt}. Save the value of @var{lhandler} to | |
811 | use as a callback when a complete line of input has been entered. | |
812 | @end deftypefun | |
813 | ||
814 | @deftypefun void rl_callback_read_char () | |
815 | Whenever an application determines that keyboard input is available, it | |
816 | should call @code{rl_callback_read_char()}, which will read the next | |
817 | character from the current input source. If that character completes the | |
818 | line, @code{rl_callback_read_char} will invoke the @var{lhandler} | |
819 | function saved by @code{rl_callback_handler_install} to process the | |
820 | line. @code{EOF} is indicated by calling @var{lhandler} with a | |
821 | @code{NULL} line. | |
822 | @end deftypefun | |
823 | ||
824 | @deftypefun void rl_callback_handler_remove () | |
825 | Restore the terminal to its initial state and remove the line handler. | |
826 | This may be called from within a callback as well as independently. | |
827 | @end deftypefun | |
828 | ||
829 | @subsection An Example | |
830 | ||
831 | Here is a function which changes lowercase characters to their uppercase | |
832 | equivalents, and uppercase characters to lowercase. If | |
833 | this function was bound to @samp{M-c}, then typing @samp{M-c} would | |
834 | change the case of the character under point. Typing @samp{M-1 0 M-c} | |
835 | would change the case of the following 10 characters, leaving the cursor on | |
836 | the last character changed. | |
837 | ||
838 | @example | |
839 | /* Invert the case of the COUNT following characters. */ | |
840 | int | |
841 | invert_case_line (count, key) | |
842 | int count, key; | |
843 | @{ | |
844 | register int start, end, i; | |
845 | ||
846 | start = rl_point; | |
847 | ||
848 | if (rl_point >= rl_end) | |
849 | return (0); | |
850 | ||
851 | if (count < 0) | |
852 | @{ | |
853 | direction = -1; | |
854 | count = -count; | |
855 | @} | |
856 | else | |
857 | direction = 1; | |
858 | ||
859 | /* Find the end of the range to modify. */ | |
860 | end = start + (count * direction); | |
861 | ||
862 | /* Force it to be within range. */ | |
863 | if (end > rl_end) | |
864 | end = rl_end; | |
865 | else if (end < 0) | |
866 | end = 0; | |
867 | ||
868 | if (start == end) | |
869 | return (0); | |
870 | ||
871 | if (start > end) | |
872 | @{ | |
873 | int temp = start; | |
874 | start = end; | |
875 | end = temp; | |
876 | @} | |
877 | ||
878 | /* Tell readline that we are modifying the line, so it will save | |
879 | the undo information. */ | |
880 | rl_modifying (start, end); | |
881 | ||
882 | for (i = start; i != end; i++) | |
883 | @{ | |
884 | if (uppercase_p (rl_line_buffer[i])) | |
885 | rl_line_buffer[i] = to_lower (rl_line_buffer[i]); | |
886 | else if (lowercase_p (rl_line_buffer[i])) | |
887 | rl_line_buffer[i] = to_upper (rl_line_buffer[i]); | |
888 | @} | |
889 | /* Move point to on top of the last character changed. */ | |
890 | rl_point = (direction == 1) ? end - 1 : start; | |
891 | return (0); | |
892 | @} | |
893 | @end example | |
894 | ||
c862e87b JM |
895 | @node Readline Signal Handling |
896 | @section Readline Signal Handling | |
897 | ||
898 | Signals are asynchronous events sent to a process by the Unix kernel, | |
899 | sometimes on behalf of another process. They are intended to indicate | |
900 | exceptional events, like a user pressing the interrupt key on his | |
901 | terminal, or a network connection being broken. There is a class of | |
902 | signals that can be sent to the process currently reading input from | |
903 | the keyboard. Since Readline changes the terminal attributes when it | |
904 | is called, it needs to perform special processing when a signal is | |
905 | received to restore the terminal to a sane state, or provide application | |
906 | writers with functions to do so manually. | |
907 | ||
908 | Readline contains an internal signal handler that is installed for a | |
909 | number of signals (@code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, | |
910 | @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}). | |
911 | When one of these signals is received, the signal handler | |
912 | will reset the terminal attributes to those that were in effect before | |
913 | @code{readline ()} was called, reset the signal handling to what it was | |
914 | before @code{readline ()} was called, and resend the signal to the calling | |
915 | application. | |
916 | If and when the calling application's signal handler returns, Readline | |
917 | will reinitialize the terminal and continue to accept input. | |
918 | When a @code{SIGINT} is received, the Readline signal handler performs | |
919 | some additional work, which will cause any partially-entered line to be | |
920 | aborted (see the description of @code{rl_free_line_state ()}). | |
921 | ||
922 | There is an additional Readline signal handler, for @code{SIGWINCH}, which | |
923 | the kernel sends to a process whenever the terminal's size changes (for | |
924 | example, if a user resizes an @code{xterm}). The Readline @code{SIGWINCH} | |
925 | handler updates Readline's internal screen size state, and then calls any | |
926 | @code{SIGWINCH} signal handler the calling application has installed. | |
927 | Readline calls the application's @code{SIGWINCH} signal handler without | |
928 | resetting the terminal to its original state. If the application's signal | |
929 | handler does more than update its idea of the terminal size and return (for | |
930 | example, a @code{longjmp} back to a main processing loop), it @emph{must} | |
931 | call @code{rl_cleanup_after_signal ()} (described below), to restore the | |
932 | terminal state. | |
933 | ||
934 | Readline provides two variables that allow application writers to | |
935 | control whether or not it will catch certain signals and act on them | |
936 | when they are received. It is important that applications change the | |
937 | values of these variables only when calling @code{readline ()}, not in | |
938 | a signal handler, so Readline's internal signal state is not corrupted. | |
939 | ||
940 | @deftypevar int rl_catch_signals | |
941 | If this variable is non-zero, Readline will install signal handlers for | |
942 | @code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, @code{SIGALRM}, | |
943 | @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}. | |
944 | ||
945 | The default value of @code{rl_catch_signals} is 1. | |
946 | @end deftypevar | |
947 | ||
948 | @deftypevar int rl_catch_sigwinch | |
949 | If this variable is non-zero, Readline will install a signal handler for | |
950 | @code{SIGWINCH}. | |
951 | ||
952 | The default value of @code{rl_catch_sigwinch} is 1. | |
953 | @end deftypevar | |
954 | ||
955 | If an application does not wish to have Readline catch any signals, or | |
956 | to handle signals other than those Readline catches (@code{SIGHUP}, | |
957 | for example), | |
958 | Readline provides convenience functions to do the necessary terminal | |
959 | and internal state cleanup upon receipt of a signal. | |
960 | ||
961 | @deftypefun void rl_cleanup_after_signal (void) | |
962 | This function will reset the state of the terminal to what it was before | |
963 | @code{readline ()} was called, and remove the Readline signal handlers for | |
964 | all signals, depending on the values of @code{rl_catch_signals} and | |
965 | @code{rl_catch_sigwinch}. | |
966 | @end deftypefun | |
967 | ||
968 | @deftypefun void rl_free_line_state (void) | |
969 | This will free any partial state associated with the current input line | |
970 | (undo information, any partial history entry, any partially-entered | |
971 | keyboard macro, and any partially-entered numeric argument). This | |
972 | should be called before @code{rl_cleanup_after_signal ()}. The | |
973 | Readline signal handler for @code{SIGINT} calls this to abort the | |
974 | current input line. | |
975 | @end deftypefun | |
976 | ||
977 | @deftypefun void rl_reset_after_signal (void) | |
978 | This will reinitialize the terminal and reinstall any Readline signal | |
979 | handlers, depending on the values of @code{rl_catch_signals} and | |
980 | @code{rl_catch_sigwinch}. | |
981 | @end deftypefun | |
982 | ||
983 | If an application does not wish Readline to catch @code{SIGWINCH}, it may | |
984 | call @code{rl_resize_terminal ()} to force Readline to update its idea of | |
985 | the terminal size when a @code{SIGWINCH} is received. | |
986 | ||
987 | @deftypefun void rl_resize_terminal (void) | |
988 | Update Readline's internal screen size. | |
989 | @end deftypefun | |
990 | ||
991 | The following functions install and remove Readline's signal handlers. | |
992 | ||
993 | @deftypefun int rl_set_signals (void) | |
994 | Install Readline's signal handler for @code{SIGINT}, @code{SIGQUIT}, | |
995 | @code{SIGTERM}, @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, | |
996 | @code{SIGTTOU}, and @code{SIGWINCH}, depending on the values of | |
997 | @code{rl_catch_signals} and @code{rl_catch_sigwinch}. | |
998 | @end deftypefun | |
999 | ||
1000 | @deftypefun int rl_clear_signals (void) | |
1001 | Remove all of the Readline signal handlers installed by | |
1002 | @code{rl_set_signals ()}. | |
1003 | @end deftypefun | |
1004 | ||
d60d9f65 SS |
1005 | @node Custom Completers |
1006 | @section Custom Completers | |
1007 | ||
1008 | Typically, a program that reads commands from the user has a way of | |
1009 | disambiguating commands and data. If your program is one of these, then | |
1010 | it can provide completion for commands, data, or both. | |
1011 | The following sections describe how your program and Readline | |
1012 | cooperate to provide this service. | |
1013 | ||
1014 | @menu | |
1015 | * How Completing Works:: The logic used to do completion. | |
1016 | * Completion Functions:: Functions provided by Readline. | |
1017 | * Completion Variables:: Variables which control completion. | |
1018 | * A Short Completion Example:: An example of writing completer subroutines. | |
1019 | @end menu | |
1020 | ||
1021 | @node How Completing Works | |
1022 | @subsection How Completing Works | |
1023 | ||
1024 | In order to complete some text, the full list of possible completions | |
1025 | must be available. That is, it is not possible to accurately | |
1026 | expand a partial word without knowing all of the possible words | |
1027 | which make sense in that context. The Readline library provides | |
1028 | the user interface to completion, and two of the most common | |
1029 | completion functions: filename and username. For completing other types | |
1030 | of text, you must write your own completion function. This section | |
1031 | describes exactly what such functions must do, and provides an example. | |
1032 | ||
1033 | There are three major functions used to perform completion: | |
1034 | ||
1035 | @enumerate | |
1036 | @item | |
1037 | The user-interface function @code{rl_complete ()}. This function is | |
1038 | called with the same arguments as other Readline | |
1039 | functions intended for interactive use: @var{count} and | |
1040 | @var{invoking_key}. It isolates the word to be completed and calls | |
1041 | @code{completion_matches ()} to generate a list of possible completions. | |
1042 | It then either lists the possible completions, inserts the possible | |
1043 | completions, or actually performs the | |
1044 | completion, depending on which behavior is desired. | |
1045 | ||
1046 | @item | |
1047 | The internal function @code{completion_matches ()} uses your | |
1048 | @dfn{generator} function to generate the list of possible matches, and | |
1049 | then returns the array of these matches. You should place the address | |
1050 | of your generator function in @code{rl_completion_entry_function}. | |
1051 | ||
1052 | @item | |
1053 | The generator function is called repeatedly from | |
1054 | @code{completion_matches ()}, returning a string each time. The | |
1055 | arguments to the generator function are @var{text} and @var{state}. | |
1056 | @var{text} is the partial word to be completed. @var{state} is zero the | |
1057 | first time the function is called, allowing the generator to perform | |
1058 | any necessary initialization, and a positive non-zero integer for | |
1059 | each subsequent call. When the generator function returns | |
1060 | @code{(char *)NULL} this signals @code{completion_matches ()} that there are | |
1061 | no more possibilities left. Usually the generator function computes the | |
1062 | list of possible completions when @var{state} is zero, and returns them | |
1063 | one at a time on subsequent calls. Each string the generator function | |
1064 | returns as a match must be allocated with @code{malloc()}; Readline | |
1065 | frees the strings when it has finished with them. | |
1066 | ||
1067 | @end enumerate | |
1068 | ||
1069 | @deftypefun int rl_complete (int ignore, int invoking_key) | |
1070 | Complete the word at or before point. You have supplied the function | |
1071 | that does the initial simple matching selection algorithm (see | |
1072 | @code{completion_matches ()}). The default is to do filename completion. | |
1073 | @end deftypefun | |
1074 | ||
1075 | @deftypevar {Function *} rl_completion_entry_function | |
1076 | This is a pointer to the generator function for @code{completion_matches | |
1077 | ()}. If the value of @code{rl_completion_entry_function} is | |
1078 | @code{(Function *)NULL} then the default filename generator function, | |
1079 | @code{filename_completion_function ()}, is used. | |
1080 | @end deftypevar | |
1081 | ||
1082 | @node Completion Functions | |
1083 | @subsection Completion Functions | |
1084 | ||
1085 | Here is the complete list of callable completion functions present in | |
1086 | Readline. | |
1087 | ||
1088 | @deftypefun int rl_complete_internal (int what_to_do) | |
1089 | Complete the word at or before point. @var{what_to_do} says what to do | |
1090 | with the completion. A value of @samp{?} means list the possible | |
1091 | completions. @samp{TAB} means do standard completion. @samp{*} means | |
1092 | insert all of the possible completions. @samp{!} means to display | |
1093 | all of the possible completions, if there is more than one, as well as | |
1094 | performing partial completion. | |
1095 | @end deftypefun | |
1096 | ||
1097 | @deftypefun int rl_complete (int ignore, int invoking_key) | |
1098 | Complete the word at or before point. You have supplied the function | |
1099 | that does the initial simple matching selection algorithm (see | |
1100 | @code{completion_matches ()} and @code{rl_completion_entry_function}). | |
1101 | The default is to do filename | |
1102 | completion. This calls @code{rl_complete_internal ()} with an | |
1103 | argument depending on @var{invoking_key}. | |
1104 | @end deftypefun | |
1105 | ||
1106 | @deftypefun int rl_possible_completions (int count, int invoking_key)) | |
1107 | List the possible completions. See description of @code{rl_complete | |
1108 | ()}. This calls @code{rl_complete_internal ()} with an argument of | |
1109 | @samp{?}. | |
1110 | @end deftypefun | |
1111 | ||
1112 | @deftypefun int rl_insert_completions (int count, int invoking_key)) | |
1113 | Insert the list of possible completions into the line, deleting the | |
1114 | partially-completed word. See description of @code{rl_complete ()}. | |
1115 | This calls @code{rl_complete_internal ()} with an argument of @samp{*}. | |
1116 | @end deftypefun | |
1117 | ||
1118 | @deftypefun {char **} completion_matches (char *text, CPFunction *entry_func) | |
1119 | Returns an array of @code{(char *)} which is a list of completions for | |
1120 | @var{text}. If there are no completions, returns @code{(char **)NULL}. | |
1121 | The first entry in the returned array is the substitution for @var{text}. | |
1122 | The remaining entries are the possible completions. The array is | |
1123 | terminated with a @code{NULL} pointer. | |
1124 | ||
1125 | @var{entry_func} is a function of two args, and returns a | |
1126 | @code{(char *)}. The first argument is @var{text}. The second is a | |
1127 | state argument; it is zero on the first call, and non-zero on subsequent | |
1128 | calls. @var{entry_func} returns a @code{NULL} pointer to the caller | |
1129 | when there are no more matches. | |
1130 | @end deftypefun | |
1131 | ||
1132 | @deftypefun {char *} filename_completion_function (char *text, int state) | |
1133 | A generator function for filename completion in the general case. Note | |
1134 | that completion in Bash is a little different because of all | |
1135 | the pathnames that must be followed when looking up completions for a | |
1136 | command. The Bash source is a useful reference for writing custom | |
1137 | completion functions. | |
1138 | @end deftypefun | |
1139 | ||
1140 | @deftypefun {char *} username_completion_function (char *text, int state) | |
1141 | A completion generator for usernames. @var{text} contains a partial | |
1142 | username preceded by a random character (usually @samp{~}). As with all | |
1143 | completion generators, @var{state} is zero on the first call and non-zero | |
1144 | for subsequent calls. | |
1145 | @end deftypefun | |
1146 | ||
1147 | @node Completion Variables | |
1148 | @subsection Completion Variables | |
1149 | ||
1150 | @deftypevar {Function *} rl_completion_entry_function | |
1151 | A pointer to the generator function for @code{completion_matches ()}. | |
1b17e766 | 1152 | @code{NULL} means to use @code{filename_completion_function ()}, the default |
d60d9f65 SS |
1153 | filename completer. |
1154 | @end deftypevar | |
1155 | ||
1156 | @deftypevar {CPPFunction *} rl_attempted_completion_function | |
1157 | A pointer to an alternative function to create matches. | |
1158 | The function is called with @var{text}, @var{start}, and @var{end}. | |
1159 | @var{start} and @var{end} are indices in @code{rl_line_buffer} saying | |
1160 | what the boundaries of @var{text} are. If this function exists and | |
1161 | returns @code{NULL}, or if this variable is set to @code{NULL}, then | |
1162 | @code{rl_complete ()} will call the value of | |
1163 | @code{rl_completion_entry_function} to generate matches, otherwise the | |
1164 | array of strings returned will be used. | |
1165 | @end deftypevar | |
1166 | ||
1167 | @deftypevar {CPFunction *} rl_filename_quoting_function | |
1168 | A pointer to a function that will quote a filename in an application- | |
1169 | specific fashion. This is called if filename completion is being | |
1170 | attempted and one of the characters in @code{rl_filename_quote_characters} | |
1171 | appears in a completed filename. The function is called with | |
1172 | @var{text}, @var{match_type}, and @var{quote_pointer}. The @var{text} | |
1173 | is the filename to be quoted. The @var{match_type} is either | |
1174 | @code{SINGLE_MATCH}, if there is only one completion match, or | |
1175 | @code{MULT_MATCH}. Some functions use this to decide whether or not to | |
1176 | insert a closing quote character. The @var{quote_pointer} is a pointer | |
1177 | to any opening quote character the user typed. Some functions choose | |
1178 | to reset this character. | |
1179 | @end deftypevar | |
1180 | ||
1181 | @deftypevar {CPFunction *} rl_filename_dequoting_function | |
1182 | A pointer to a function that will remove application-specific quoting | |
1183 | characters from a filename before completion is attempted, so those | |
1184 | characters do not interfere with matching the text against names in | |
1185 | the filesystem. It is called with @var{text}, the text of the word | |
1186 | to be dequoted, and @var{quote_char}, which is the quoting character | |
1187 | that delimits the filename (usually @samp{'} or @samp{"}). If | |
1188 | @var{quote_char} is zero, the filename was not in an embedded string. | |
1189 | @end deftypevar | |
1190 | ||
1191 | @deftypevar {Function *} rl_char_is_quoted_p | |
1192 | A pointer to a function to call that determines whether or not a specific | |
1193 | character in the line buffer is quoted, according to whatever quoting | |
1194 | mechanism the program calling readline uses. The function is called with | |
1195 | two arguments: @var{text}, the text of the line, and @var{index}, the | |
1196 | index of the character in the line. It is used to decide whether a | |
1197 | character found in @code{rl_completer_word_break_characters} should be | |
1198 | used to break words for the completer. | |
1199 | @end deftypevar | |
1200 | ||
1201 | @deftypevar int rl_completion_query_items | |
1202 | Up to this many items will be displayed in response to a | |
1203 | possible-completions call. After that, we ask the user if she is sure | |
1204 | she wants to see them all. The default value is 100. | |
1205 | @end deftypevar | |
1206 | ||
1207 | @deftypevar {char *} rl_basic_word_break_characters | |
1208 | The basic list of characters that signal a break between words for the | |
1209 | completer routine. The default value of this variable is the characters | |
1210 | which break words for completion in Bash, i.e., | |
1211 | @code{" \t\n\"\\'`@@$><=;|&@{("}. | |
1212 | @end deftypevar | |
1213 | ||
1214 | @deftypevar {char *} rl_basic_quote_characters | |
1215 | List of quote characters which can cause a word break. | |
1216 | @end deftypevar | |
1217 | ||
1218 | @deftypevar {char *} rl_completer_word_break_characters | |
1219 | The list of characters that signal a break between words for | |
1220 | @code{rl_complete_internal ()}. The default list is the value of | |
1221 | @code{rl_basic_word_break_characters}. | |
1222 | @end deftypevar | |
1223 | ||
1224 | @deftypevar {char *} rl_completer_quote_characters | |
1225 | List of characters which can be used to quote a substring of the line. | |
1226 | Completion occurs on the entire substring, and within the substring | |
1227 | @code{rl_completer_word_break_characters} are treated as any other character, | |
1228 | unless they also appear within this list. | |
1229 | @end deftypevar | |
1230 | ||
1231 | @deftypevar {char *} rl_filename_quote_characters | |
1232 | A list of characters that cause a filename to be quoted by the completer | |
1233 | when they appear in a completed filename. The default is the null string. | |
1234 | @end deftypevar | |
1235 | ||
1236 | @deftypevar {char *} rl_special_prefixes | |
1237 | The list of characters that are word break characters, but should be | |
1238 | left in @var{text} when it is passed to the completion function. | |
1239 | Programs can use this to help determine what kind of completing to do. | |
1240 | For instance, Bash sets this variable to "$@@" so that it can complete | |
1241 | shell variables and hostnames. | |
1242 | @end deftypevar | |
1243 | ||
1244 | @deftypevar {int} rl_completion_append_character | |
1245 | When a single completion alternative matches at the end of the command | |
1246 | line, this character is appended to the inserted completion text. The | |
1247 | default is a space character (@samp{ }). Setting this to the null | |
1248 | character (@samp{\0}) prevents anything being appended automatically. | |
1249 | This can be changed in custom completion functions to | |
1250 | provide the ``most sensible word separator character'' according to | |
1251 | an application-specific command line syntax specification. | |
1252 | @end deftypevar | |
1253 | ||
1254 | @deftypevar int rl_ignore_completion_duplicates | |
1255 | If non-zero, then disallow duplicates in the matches. Default is 1. | |
1256 | @end deftypevar | |
1257 | ||
1258 | @deftypevar int rl_filename_completion_desired | |
1259 | Non-zero means that the results of the matches are to be treated as | |
1260 | filenames. This is @emph{always} zero on entry, and can only be changed | |
1261 | within a completion entry generator function. If it is set to a non-zero | |
1262 | value, directory names have a slash appended and Readline attempts to | |
1263 | quote completed filenames if they contain any embedded word break | |
1264 | characters. | |
1265 | @end deftypevar | |
1266 | ||
1267 | @deftypevar int rl_filename_quoting_desired | |
1268 | Non-zero means that the results of the matches are to be quoted using | |
1269 | double quotes (or an application-specific quoting mechanism) if the | |
1270 | completed filename contains any characters in | |
1271 | @code{rl_filename_quote_chars}. This is @emph{always} non-zero | |
1272 | on entry, and can only be changed within a completion entry generator | |
1273 | function. The quoting is effected via a call to the function pointed to | |
1274 | by @code{rl_filename_quoting_function}. | |
1275 | @end deftypevar | |
1276 | ||
1277 | @deftypevar int rl_inhibit_completion | |
1278 | If this variable is non-zero, completion is inhibit<ed. The completion | |
1279 | character will be inserted as any other bound to @code{self-insert}. | |
1280 | @end deftypevar | |
1281 | ||
1282 | @deftypevar {Function *} rl_ignore_some_completions_function | |
1283 | This function, if defined, is called by the completer when real filename | |
1284 | completion is done, after all the matching names have been generated. | |
1285 | It is passed a @code{NULL} terminated array of matches. | |
1286 | The first element (@code{matches[0]}) is the | |
1287 | maximal substring common to all matches. This function can | |
1288 | re-arrange the list of matches as required, but each element deleted | |
1289 | from the array must be freed. | |
1290 | @end deftypevar | |
1291 | ||
1292 | @deftypevar {Function *} rl_directory_completion_hook | |
1293 | This function, if defined, is allowed to modify the directory portion | |
1294 | of filenames Readline completes. It is called with the address of a | |
1295 | string (the current directory name) as an argument. It could be used | |
1296 | to expand symbolic links or shell variables in pathnames. | |
1297 | @end deftypevar | |
c862e87b JM |
1298 | |
1299 | @deftypevar {VFunction *} rl_completion_display_matches_hook | |
1300 | If non-zero, then this is the address of a function to call when | |
1301 | completing a word would normally display the list of possible matches. | |
1302 | This function is called in lieu of Readline displaying the list. | |
1303 | It takes three arguments: | |
1304 | (@code{char **}@var{matches}, @code{int} @var{num_matches}, @code{int} @var{max_length}) | |
1305 | where @var{matches} is the array of matching strings, | |
1306 | @var{num_matches} is the number of strings in that array, and | |
1307 | @var{max_length} is the length of the longest string in that array. | |
1308 | Readline provides a convenience function, @code{rl_display_match_list}, | |
1309 | that takes care of doing the display to Readline's output stream. That | |
1310 | function may be called from this hook. | |
1311 | @end deftypevar | |
d60d9f65 SS |
1312 | |
1313 | @node A Short Completion Example | |
1314 | @subsection A Short Completion Example | |
1315 | ||
1316 | Here is a small application demonstrating the use of the GNU Readline | |
1317 | library. It is called @code{fileman}, and the source code resides in | |
1318 | @file{examples/fileman.c}. This sample application provides | |
1319 | completion of command names, line editing features, and access to the | |
1320 | history list. | |
1321 | ||
1322 | @page | |
1323 | @smallexample | |
1324 | /* fileman.c -- A tiny application which demonstrates how to use the | |
1325 | GNU Readline library. This application interactively allows users | |
1326 | to manipulate files and their modes. */ | |
1327 | ||
1328 | #include <stdio.h> | |
1329 | #include <sys/types.h> | |
1330 | #include <sys/file.h> | |
1331 | #include <sys/stat.h> | |
1332 | #include <sys/errno.h> | |
1333 | ||
1334 | #include <readline/readline.h> | |
1335 | #include <readline/history.h> | |
1336 | ||
1337 | extern char *getwd (); | |
1338 | extern char *xmalloc (); | |
1339 | ||
1340 | /* The names of functions that actually do the manipulation. */ | |
1341 | int com_list (), com_view (), com_rename (), com_stat (), com_pwd (); | |
1342 | int com_delete (), com_help (), com_cd (), com_quit (); | |
1343 | ||
1344 | /* A structure which contains information on the commands this program | |
1345 | can understand. */ | |
1346 | ||
1347 | typedef struct @{ | |
1348 | char *name; /* User printable name of the function. */ | |
1349 | Function *func; /* Function to call to do the job. */ | |
1350 | char *doc; /* Documentation for this function. */ | |
1351 | @} COMMAND; | |
1352 | ||
1353 | COMMAND commands[] = @{ | |
1354 | @{ "cd", com_cd, "Change to directory DIR" @}, | |
1355 | @{ "delete", com_delete, "Delete FILE" @}, | |
1356 | @{ "help", com_help, "Display this text" @}, | |
1357 | @{ "?", com_help, "Synonym for `help'" @}, | |
1358 | @{ "list", com_list, "List files in DIR" @}, | |
1359 | @{ "ls", com_list, "Synonym for `list'" @}, | |
1360 | @{ "pwd", com_pwd, "Print the current working directory" @}, | |
1361 | @{ "quit", com_quit, "Quit using Fileman" @}, | |
1362 | @{ "rename", com_rename, "Rename FILE to NEWNAME" @}, | |
1363 | @{ "stat", com_stat, "Print out statistics on FILE" @}, | |
1364 | @{ "view", com_view, "View the contents of FILE" @}, | |
1365 | @{ (char *)NULL, (Function *)NULL, (char *)NULL @} | |
1366 | @}; | |
1367 | ||
1368 | /* Forward declarations. */ | |
1369 | char *stripwhite (); | |
1370 | COMMAND *find_command (); | |
1371 | ||
1372 | /* The name of this program, as taken from argv[0]. */ | |
1373 | char *progname; | |
1374 | ||
1375 | /* When non-zero, this global means the user is done using this program. */ | |
1376 | int done; | |
1377 | ||
1378 | char * | |
1379 | dupstr (s) | |
1380 | int s; | |
1381 | @{ | |
1382 | char *r; | |
1383 | ||
1384 | r = xmalloc (strlen (s) + 1); | |
1385 | strcpy (r, s); | |
1386 | return (r); | |
1387 | @} | |
1388 | ||
1389 | main (argc, argv) | |
1390 | int argc; | |
1391 | char **argv; | |
1392 | @{ | |
1393 | char *line, *s; | |
1394 | ||
1395 | progname = argv[0]; | |
1396 | ||
1397 | initialize_readline (); /* Bind our completer. */ | |
1398 | ||
1399 | /* Loop reading and executing lines until the user quits. */ | |
1400 | for ( ; done == 0; ) | |
1401 | @{ | |
1402 | line = readline ("FileMan: "); | |
1403 | ||
1404 | if (!line) | |
1405 | break; | |
1406 | ||
1407 | /* Remove leading and trailing whitespace from the line. | |
1408 | Then, if there is anything left, add it to the history list | |
1409 | and execute it. */ | |
1410 | s = stripwhite (line); | |
1411 | ||
1412 | if (*s) | |
1413 | @{ | |
1414 | add_history (s); | |
1415 | execute_line (s); | |
1416 | @} | |
1417 | ||
1418 | free (line); | |
1419 | @} | |
1420 | exit (0); | |
1421 | @} | |
1422 | ||
1423 | /* Execute a command line. */ | |
1424 | int | |
1425 | execute_line (line) | |
1426 | char *line; | |
1427 | @{ | |
1428 | register int i; | |
1429 | COMMAND *command; | |
1430 | char *word; | |
1431 | ||
1432 | /* Isolate the command word. */ | |
1433 | i = 0; | |
1434 | while (line[i] && whitespace (line[i])) | |
1435 | i++; | |
1436 | word = line + i; | |
1437 | ||
1438 | while (line[i] && !whitespace (line[i])) | |
1439 | i++; | |
1440 | ||
1441 | if (line[i]) | |
1442 | line[i++] = '\0'; | |
1443 | ||
1444 | command = find_command (word); | |
1445 | ||
1446 | if (!command) | |
1447 | @{ | |
1448 | fprintf (stderr, "%s: No such command for FileMan.\n", word); | |
1449 | return (-1); | |
1450 | @} | |
1451 | ||
1452 | /* Get argument to command, if any. */ | |
1453 | while (whitespace (line[i])) | |
1454 | i++; | |
1455 | ||
1456 | word = line + i; | |
1457 | ||
1458 | /* Call the function. */ | |
1459 | return ((*(command->func)) (word)); | |
1460 | @} | |
1461 | ||
1462 | /* Look up NAME as the name of a command, and return a pointer to that | |
1463 | command. Return a NULL pointer if NAME isn't a command name. */ | |
1464 | COMMAND * | |
1465 | find_command (name) | |
1466 | char *name; | |
1467 | @{ | |
1468 | register int i; | |
1469 | ||
1470 | for (i = 0; commands[i].name; i++) | |
1471 | if (strcmp (name, commands[i].name) == 0) | |
1472 | return (&commands[i]); | |
1473 | ||
1474 | return ((COMMAND *)NULL); | |
1475 | @} | |
1476 | ||
1477 | /* Strip whitespace from the start and end of STRING. Return a pointer | |
1478 | into STRING. */ | |
1479 | char * | |
1480 | stripwhite (string) | |
1481 | char *string; | |
1482 | @{ | |
1483 | register char *s, *t; | |
1484 | ||
1485 | for (s = string; whitespace (*s); s++) | |
1486 | ; | |
1487 | ||
1488 | if (*s == 0) | |
1489 | return (s); | |
1490 | ||
1491 | t = s + strlen (s) - 1; | |
1492 | while (t > s && whitespace (*t)) | |
1493 | t--; | |
1494 | *++t = '\0'; | |
1495 | ||
1496 | return s; | |
1497 | @} | |
1498 | ||
1499 | /* **************************************************************** */ | |
1500 | /* */ | |
1501 | /* Interface to Readline Completion */ | |
1502 | /* */ | |
1503 | /* **************************************************************** */ | |
1504 | ||
1505 | char *command_generator (); | |
1506 | char **fileman_completion (); | |
1507 | ||
1508 | /* Tell the GNU Readline library how to complete. We want to try to complete | |
1509 | on command names if this is the first word in the line, or on filenames | |
1510 | if not. */ | |
1511 | initialize_readline () | |
1512 | @{ | |
1513 | /* Allow conditional parsing of the ~/.inputrc file. */ | |
1514 | rl_readline_name = "FileMan"; | |
1515 | ||
1516 | /* Tell the completer that we want a crack first. */ | |
1517 | rl_attempted_completion_function = (CPPFunction *)fileman_completion; | |
1518 | @} | |
1519 | ||
1520 | /* Attempt to complete on the contents of TEXT. START and END bound the | |
1521 | region of rl_line_buffer that contains the word to complete. TEXT is | |
1522 | the word to complete. We can use the entire contents of rl_line_buffer | |
1523 | in case we want to do some simple parsing. Return the array of matches, | |
1524 | or NULL if there aren't any. */ | |
1525 | char ** | |
1526 | fileman_completion (text, start, end) | |
1527 | char *text; | |
1528 | int start, end; | |
1529 | @{ | |
1530 | char **matches; | |
1531 | ||
1532 | matches = (char **)NULL; | |
1533 | ||
1534 | /* If this word is at the start of the line, then it is a command | |
1535 | to complete. Otherwise it is the name of a file in the current | |
1536 | directory. */ | |
1537 | if (start == 0) | |
1538 | matches = completion_matches (text, command_generator); | |
1539 | ||
1540 | return (matches); | |
1541 | @} | |
1542 | ||
1543 | /* Generator function for command completion. STATE lets us know whether | |
1544 | to start from scratch; without any state (i.e. STATE == 0), then we | |
1545 | start at the top of the list. */ | |
1546 | char * | |
1547 | command_generator (text, state) | |
1548 | char *text; | |
1549 | int state; | |
1550 | @{ | |
1551 | static int list_index, len; | |
1552 | char *name; | |
1553 | ||
1554 | /* If this is a new word to complete, initialize now. This includes | |
1555 | saving the length of TEXT for efficiency, and initializing the index | |
1556 | variable to 0. */ | |
1557 | if (!state) | |
1558 | @{ | |
1559 | list_index = 0; | |
1560 | len = strlen (text); | |
1561 | @} | |
1562 | ||
1563 | /* Return the next name which partially matches from the command list. */ | |
1564 | while (name = commands[list_index].name) | |
1565 | @{ | |
1566 | list_index++; | |
1567 | ||
1568 | if (strncmp (name, text, len) == 0) | |
1569 | return (dupstr(name)); | |
1570 | @} | |
1571 | ||
1572 | /* If no names matched, then return NULL. */ | |
1573 | return ((char *)NULL); | |
1574 | @} | |
1575 | ||
1576 | /* **************************************************************** */ | |
1577 | /* */ | |
1578 | /* FileMan Commands */ | |
1579 | /* */ | |
1580 | /* **************************************************************** */ | |
1581 | ||
1582 | /* String to pass to system (). This is for the LIST, VIEW and RENAME | |
1583 | commands. */ | |
1584 | static char syscom[1024]; | |
1585 | ||
1586 | /* List the file(s) named in arg. */ | |
1587 | com_list (arg) | |
1588 | char *arg; | |
1589 | @{ | |
1590 | if (!arg) | |
1591 | arg = ""; | |
1592 | ||
1593 | sprintf (syscom, "ls -FClg %s", arg); | |
1594 | return (system (syscom)); | |
1595 | @} | |
1596 | ||
1597 | com_view (arg) | |
1598 | char *arg; | |
1599 | @{ | |
1600 | if (!valid_argument ("view", arg)) | |
1601 | return 1; | |
1602 | ||
1603 | sprintf (syscom, "more %s", arg); | |
1604 | return (system (syscom)); | |
1605 | @} | |
1606 | ||
1607 | com_rename (arg) | |
1608 | char *arg; | |
1609 | @{ | |
1610 | too_dangerous ("rename"); | |
1611 | return (1); | |
1612 | @} | |
1613 | ||
1614 | com_stat (arg) | |
1615 | char *arg; | |
1616 | @{ | |
1617 | struct stat finfo; | |
1618 | ||
1619 | if (!valid_argument ("stat", arg)) | |
1620 | return (1); | |
1621 | ||
1622 | if (stat (arg, &finfo) == -1) | |
1623 | @{ | |
1624 | perror (arg); | |
1625 | return (1); | |
1626 | @} | |
1627 | ||
1628 | printf ("Statistics for `%s':\n", arg); | |
1629 | ||
1630 | printf ("%s has %d link%s, and is %d byte%s in length.\n", arg, | |
1631 | finfo.st_nlink, | |
1632 | (finfo.st_nlink == 1) ? "" : "s", | |
1633 | finfo.st_size, | |
1634 | (finfo.st_size == 1) ? "" : "s"); | |
1635 | printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime)); | |
1636 | printf (" Last access at: %s", ctime (&finfo.st_atime)); | |
1637 | printf (" Last modified at: %s", ctime (&finfo.st_mtime)); | |
1638 | return (0); | |
1639 | @} | |
1640 | ||
1641 | com_delete (arg) | |
1642 | char *arg; | |
1643 | @{ | |
1644 | too_dangerous ("delete"); | |
1645 | return (1); | |
1646 | @} | |
1647 | ||
1648 | /* Print out help for ARG, or for all of the commands if ARG is | |
1649 | not present. */ | |
1650 | com_help (arg) | |
1651 | char *arg; | |
1652 | @{ | |
1653 | register int i; | |
1654 | int printed = 0; | |
1655 | ||
1656 | for (i = 0; commands[i].name; i++) | |
1657 | @{ | |
1658 | if (!*arg || (strcmp (arg, commands[i].name) == 0)) | |
1659 | @{ | |
1660 | printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc); | |
1661 | printed++; | |
1662 | @} | |
1663 | @} | |
1664 | ||
1665 | if (!printed) | |
1666 | @{ | |
1667 | printf ("No commands match `%s'. Possibilties are:\n", arg); | |
1668 | ||
1669 | for (i = 0; commands[i].name; i++) | |
1670 | @{ | |
1671 | /* Print in six columns. */ | |
1672 | if (printed == 6) | |
1673 | @{ | |
1674 | printed = 0; | |
1675 | printf ("\n"); | |
1676 | @} | |
1677 | ||
1678 | printf ("%s\t", commands[i].name); | |
1679 | printed++; | |
1680 | @} | |
1681 | ||
1682 | if (printed) | |
1683 | printf ("\n"); | |
1684 | @} | |
1685 | return (0); | |
1686 | @} | |
1687 | ||
1688 | /* Change to the directory ARG. */ | |
1689 | com_cd (arg) | |
1690 | char *arg; | |
1691 | @{ | |
1692 | if (chdir (arg) == -1) | |
1693 | @{ | |
1694 | perror (arg); | |
1695 | return 1; | |
1696 | @} | |
1697 | ||
1698 | com_pwd (""); | |
1699 | return (0); | |
1700 | @} | |
1701 | ||
1702 | /* Print out the current working directory. */ | |
1703 | com_pwd (ignore) | |
1704 | char *ignore; | |
1705 | @{ | |
1706 | char dir[1024], *s; | |
1707 | ||
1708 | s = getwd (dir); | |
1709 | if (s == 0) | |
1710 | @{ | |
1711 | printf ("Error getting pwd: %s\n", dir); | |
1712 | return 1; | |
1713 | @} | |
1714 | ||
1715 | printf ("Current directory is %s\n", dir); | |
1716 | return 0; | |
1717 | @} | |
1718 | ||
1719 | /* The user wishes to quit using this program. Just set DONE non-zero. */ | |
1720 | com_quit (arg) | |
1721 | char *arg; | |
1722 | @{ | |
1723 | done = 1; | |
1724 | return (0); | |
1725 | @} | |
1726 | ||
1727 | /* Function which tells you that you can't do this. */ | |
1728 | too_dangerous (caller) | |
1729 | char *caller; | |
1730 | @{ | |
1731 | fprintf (stderr, | |
1732 | "%s: Too dangerous for me to distribute. Write it yourself.\n", | |
1733 | caller); | |
1734 | @} | |
1735 | ||
1736 | /* Return non-zero if ARG is a valid argument for CALLER, else print | |
1737 | an error message and return zero. */ | |
1738 | int | |
1739 | valid_argument (caller, arg) | |
1740 | char *caller, *arg; | |
1741 | @{ | |
1742 | if (!arg || !*arg) | |
1743 | @{ | |
1744 | fprintf (stderr, "%s: Argument required.\n", caller); | |
1745 | return (0); | |
1746 | @} | |
1747 | ||
1748 | return (1); | |
1749 | @} | |
1750 | @end smallexample |