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b80f6443 | 1 | /* history.c -- standalone history library */ |
726f6388 | 2 | |
74091dd4 | 3 | /* Copyright (C) 1989-2021 Free Software Foundation, Inc. |
726f6388 | 4 | |
3185942a | 5 | This file contains the GNU History Library (History), a set of |
726f6388 JA |
6 | routines for managing the text of previously typed lines. |
7 | ||
3185942a | 8 | History is free software: you can redistribute it and/or modify |
726f6388 | 9 | it under the terms of the GNU General Public License as published by |
3185942a JA |
10 | the Free Software Foundation, either version 3 of the License, or |
11 | (at your option) any later version. | |
726f6388 | 12 | |
3185942a JA |
13 | History is distributed in the hope that it will be useful, |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
726f6388 | 17 | |
3185942a JA |
18 | You should have received a copy of the GNU General Public License |
19 | along with History. If not, see <http://www.gnu.org/licenses/>. | |
20 | */ | |
726f6388 JA |
21 | |
22 | /* The goal is to make the implementation transparent, so that you | |
23 | don't have to know what data types are used, just what functions | |
24 | you can call. I think I have done that. */ | |
25 | #define READLINE_LIBRARY | |
26 | ||
ccc6cda3 JA |
27 | #if defined (HAVE_CONFIG_H) |
28 | # include <config.h> | |
29 | #endif | |
30 | ||
726f6388 | 31 | #include <stdio.h> |
ccc6cda3 | 32 | |
726f6388 JA |
33 | #if defined (HAVE_STDLIB_H) |
34 | # include <stdlib.h> | |
35 | #else | |
36 | # include "ansi_stdlib.h" | |
37 | #endif /* HAVE_STDLIB_H */ | |
ccc6cda3 | 38 | |
726f6388 | 39 | #if defined (HAVE_UNISTD_H) |
cce855bc JA |
40 | # ifdef _MINIX |
41 | # include <sys/types.h> | |
42 | # endif | |
726f6388 JA |
43 | # include <unistd.h> |
44 | #endif | |
ccc6cda3 | 45 | |
a0c0a00f CR |
46 | #include <errno.h> |
47 | ||
726f6388 | 48 | #include "history.h" |
ccc6cda3 | 49 | #include "histlib.h" |
726f6388 | 50 | |
bb70624e | 51 | #include "xmalloc.h" |
726f6388 | 52 | |
a0c0a00f CR |
53 | #if !defined (errno) |
54 | extern int errno; | |
55 | #endif | |
56 | ||
57 | /* How big to make the_history when we first allocate it. */ | |
58 | #define DEFAULT_HISTORY_INITIAL_SIZE 502 | |
59 | ||
8ddc8d6e CR |
60 | #define MAX_HISTORY_INITIAL_SIZE 8192 |
61 | ||
ccc6cda3 JA |
62 | /* The number of slots to increase the_history by. */ |
63 | #define DEFAULT_HISTORY_GROW_SIZE 50 | |
726f6388 | 64 | |
74091dd4 | 65 | static char *hist_inittime (void); |
b80f6443 | 66 | |
726f6388 JA |
67 | /* **************************************************************** */ |
68 | /* */ | |
69 | /* History Functions */ | |
70 | /* */ | |
71 | /* **************************************************************** */ | |
72 | ||
73 | /* An array of HIST_ENTRY. This is where we store the history. */ | |
74 | static HIST_ENTRY **the_history = (HIST_ENTRY **)NULL; | |
75 | ||
76 | /* Non-zero means that we have enforced a limit on the amount of | |
77 | history that we save. */ | |
ccc6cda3 | 78 | static int history_stifled; |
726f6388 | 79 | |
f73dda09 JA |
80 | /* The current number of slots allocated to the input_history. */ |
81 | static int history_size; | |
82 | ||
726f6388 JA |
83 | /* If HISTORY_STIFLED is non-zero, then this is the maximum number of |
84 | entries to remember. */ | |
28ef6c31 JA |
85 | int history_max_entries; |
86 | int max_input_history; /* backwards compatibility */ | |
726f6388 JA |
87 | |
88 | /* The current location of the interactive history pointer. Just makes | |
89 | life easier for outside callers. */ | |
ccc6cda3 | 90 | int history_offset; |
726f6388 | 91 | |
ccc6cda3 JA |
92 | /* The number of strings currently stored in the history list. */ |
93 | int history_length; | |
726f6388 | 94 | |
726f6388 JA |
95 | /* The logical `base' of the history array. It defaults to 1. */ |
96 | int history_base = 1; | |
97 | ||
98 | /* Return the current HISTORY_STATE of the history. */ | |
99 | HISTORY_STATE * | |
d233b485 | 100 | history_get_history_state (void) |
726f6388 JA |
101 | { |
102 | HISTORY_STATE *state; | |
103 | ||
104 | state = (HISTORY_STATE *)xmalloc (sizeof (HISTORY_STATE)); | |
105 | state->entries = the_history; | |
106 | state->offset = history_offset; | |
107 | state->length = history_length; | |
108 | state->size = history_size; | |
109 | state->flags = 0; | |
110 | if (history_stifled) | |
111 | state->flags |= HS_STIFLED; | |
112 | ||
113 | return (state); | |
114 | } | |
115 | ||
116 | /* Set the state of the current history array to STATE. */ | |
117 | void | |
d233b485 | 118 | history_set_history_state (HISTORY_STATE *state) |
726f6388 JA |
119 | { |
120 | the_history = state->entries; | |
121 | history_offset = state->offset; | |
122 | history_length = state->length; | |
123 | history_size = state->size; | |
124 | if (state->flags & HS_STIFLED) | |
125 | history_stifled = 1; | |
126 | } | |
127 | ||
128 | /* Begin a session in which the history functions might be used. This | |
129 | initializes interactive variables. */ | |
130 | void | |
d233b485 | 131 | using_history (void) |
726f6388 JA |
132 | { |
133 | history_offset = history_length; | |
134 | } | |
135 | ||
136 | /* Return the number of bytes that the primary history entries are using. | |
b80f6443 JA |
137 | This just adds up the lengths of the_history->lines and the associated |
138 | timestamps. */ | |
726f6388 | 139 | int |
d233b485 | 140 | history_total_bytes (void) |
726f6388 JA |
141 | { |
142 | register int i, result; | |
143 | ||
28ef6c31 | 144 | for (i = result = 0; the_history && the_history[i]; i++) |
b80f6443 | 145 | result += HISTENT_BYTES (the_history[i]); |
726f6388 JA |
146 | |
147 | return (result); | |
148 | } | |
149 | ||
ccc6cda3 JA |
150 | /* Returns the magic number which says what history element we are |
151 | looking at now. In this implementation, it returns history_offset. */ | |
152 | int | |
d233b485 | 153 | where_history (void) |
ccc6cda3 JA |
154 | { |
155 | return (history_offset); | |
156 | } | |
157 | ||
158 | /* Make the current history item be the one at POS, an absolute index. | |
159 | Returns zero if POS is out of range, else non-zero. */ | |
160 | int | |
d233b485 | 161 | history_set_pos (int pos) |
ccc6cda3 JA |
162 | { |
163 | if (pos > history_length || pos < 0 || !the_history) | |
164 | return (0); | |
165 | history_offset = pos; | |
166 | return (1); | |
167 | } | |
74091dd4 CR |
168 | |
169 | /* Are we currently at the end of the history list? */ | |
170 | int | |
171 | _hs_at_end_of_history (void) | |
172 | { | |
173 | return (the_history == 0 || history_offset == history_length); | |
174 | } | |
ccc6cda3 | 175 | |
3185942a | 176 | /* Return the current history array. The caller has to be careful, since this |
ccc6cda3 JA |
177 | is the actual array of data, and could be bashed or made corrupt easily. |
178 | The array is terminated with a NULL pointer. */ | |
179 | HIST_ENTRY ** | |
d233b485 | 180 | history_list (void) |
ccc6cda3 JA |
181 | { |
182 | return (the_history); | |
183 | } | |
184 | ||
185 | /* Return the history entry at the current position, as determined by | |
186 | history_offset. If there is no entry there, return a NULL pointer. */ | |
187 | HIST_ENTRY * | |
d233b485 | 188 | current_history (void) |
ccc6cda3 JA |
189 | { |
190 | return ((history_offset == history_length) || the_history == 0) | |
191 | ? (HIST_ENTRY *)NULL | |
192 | : the_history[history_offset]; | |
193 | } | |
194 | ||
195 | /* Back up history_offset to the previous history entry, and return | |
196 | a pointer to that entry. If there is no previous entry then return | |
197 | a NULL pointer. */ | |
198 | HIST_ENTRY * | |
d233b485 | 199 | previous_history (void) |
ccc6cda3 JA |
200 | { |
201 | return history_offset ? the_history[--history_offset] : (HIST_ENTRY *)NULL; | |
202 | } | |
203 | ||
204 | /* Move history_offset forward to the next history entry, and return | |
205 | a pointer to that entry. If there is no next entry then return a | |
206 | NULL pointer. */ | |
207 | HIST_ENTRY * | |
d233b485 | 208 | next_history (void) |
ccc6cda3 JA |
209 | { |
210 | return (history_offset == history_length) ? (HIST_ENTRY *)NULL : the_history[++history_offset]; | |
211 | } | |
212 | ||
213 | /* Return the history entry which is logically at OFFSET in the history array. | |
214 | OFFSET is relative to history_base. */ | |
215 | HIST_ENTRY * | |
d233b485 | 216 | history_get (int offset) |
ccc6cda3 JA |
217 | { |
218 | int local_index; | |
219 | ||
220 | local_index = offset - history_base; | |
95732b49 | 221 | return (local_index >= history_length || local_index < 0 || the_history == 0) |
ccc6cda3 JA |
222 | ? (HIST_ENTRY *)NULL |
223 | : the_history[local_index]; | |
224 | } | |
225 | ||
0628567a | 226 | HIST_ENTRY * |
d233b485 | 227 | alloc_history_entry (char *string, char *ts) |
0628567a JA |
228 | { |
229 | HIST_ENTRY *temp; | |
230 | ||
231 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); | |
232 | ||
233 | temp->line = string ? savestring (string) : string; | |
234 | temp->data = (char *)NULL; | |
235 | temp->timestamp = ts; | |
236 | ||
237 | return temp; | |
238 | } | |
239 | ||
b80f6443 | 240 | time_t |
d233b485 | 241 | history_get_time (HIST_ENTRY *hist) |
b80f6443 JA |
242 | { |
243 | char *ts; | |
244 | time_t t; | |
245 | ||
246 | if (hist == 0 || hist->timestamp == 0) | |
247 | return 0; | |
248 | ts = hist->timestamp; | |
249 | if (ts[0] != history_comment_char) | |
250 | return 0; | |
a0c0a00f | 251 | errno = 0; |
ac50fbac | 252 | t = (time_t) strtol (ts + 1, (char **)NULL, 10); /* XXX - should use strtol() here */ |
a0c0a00f CR |
253 | if (errno == ERANGE) |
254 | return (time_t)0; | |
b80f6443 JA |
255 | return t; |
256 | } | |
257 | ||
258 | static char * | |
d233b485 | 259 | hist_inittime (void) |
b80f6443 JA |
260 | { |
261 | time_t t; | |
262 | char ts[64], *ret; | |
263 | ||
264 | t = (time_t) time ((time_t *)0); | |
265 | #if defined (HAVE_VSNPRINTF) /* assume snprintf if vsnprintf exists */ | |
266 | snprintf (ts, sizeof (ts) - 1, "X%lu", (unsigned long) t); | |
267 | #else | |
268 | sprintf (ts, "X%lu", (unsigned long) t); | |
269 | #endif | |
270 | ret = savestring (ts); | |
271 | ret[0] = history_comment_char; | |
272 | ||
273 | return ret; | |
274 | } | |
275 | ||
726f6388 JA |
276 | /* Place STRING at the end of the history list. The data field |
277 | is set to NULL. */ | |
278 | void | |
d233b485 | 279 | add_history (const char *string) |
726f6388 JA |
280 | { |
281 | HIST_ENTRY *temp; | |
e59fb114 | 282 | int new_length; |
726f6388 | 283 | |
28ef6c31 | 284 | if (history_stifled && (history_length == history_max_entries)) |
726f6388 JA |
285 | { |
286 | register int i; | |
287 | ||
288 | /* If the history is stifled, and history_length is zero, | |
28ef6c31 | 289 | and it equals history_max_entries, we don't save items. */ |
726f6388 JA |
290 | if (history_length == 0) |
291 | return; | |
292 | ||
293 | /* If there is something in the slot, then remove it. */ | |
294 | if (the_history[0]) | |
b80f6443 | 295 | (void) free_history_entry (the_history[0]); |
726f6388 | 296 | |
a0c0a00f CR |
297 | /* Copy the rest of the entries, moving down one slot. Copy includes |
298 | trailing NULL. */ | |
a0c0a00f | 299 | memmove (the_history, the_history + 1, history_length * sizeof (HIST_ENTRY *)); |
726f6388 | 300 | |
e59fb114 | 301 | new_length = history_length; |
726f6388 | 302 | history_base++; |
726f6388 JA |
303 | } |
304 | else | |
305 | { | |
ccc6cda3 | 306 | if (history_size == 0) |
726f6388 | 307 | { |
a0c0a00f | 308 | if (history_stifled && history_max_entries > 0) |
8ddc8d6e CR |
309 | history_size = (history_max_entries > MAX_HISTORY_INITIAL_SIZE) |
310 | ? MAX_HISTORY_INITIAL_SIZE | |
311 | : history_max_entries + 2; | |
a0c0a00f CR |
312 | else |
313 | history_size = DEFAULT_HISTORY_INITIAL_SIZE; | |
726f6388 | 314 | the_history = (HIST_ENTRY **)xmalloc (history_size * sizeof (HIST_ENTRY *)); |
e59fb114 | 315 | new_length = 1; |
726f6388 JA |
316 | } |
317 | else | |
318 | { | |
319 | if (history_length == (history_size - 1)) | |
320 | { | |
321 | history_size += DEFAULT_HISTORY_GROW_SIZE; | |
322 | the_history = (HIST_ENTRY **) | |
323 | xrealloc (the_history, history_size * sizeof (HIST_ENTRY *)); | |
324 | } | |
e59fb114 | 325 | new_length = history_length + 1; |
726f6388 JA |
326 | } |
327 | } | |
328 | ||
a0c0a00f | 329 | temp = alloc_history_entry ((char *)string, hist_inittime ()); |
b80f6443 | 330 | |
e59fb114 CR |
331 | the_history[new_length] = (HIST_ENTRY *)NULL; |
332 | the_history[new_length - 1] = temp; | |
333 | history_length = new_length; | |
726f6388 JA |
334 | } |
335 | ||
b80f6443 JA |
336 | /* Change the time stamp of the most recent history entry to STRING. */ |
337 | void | |
d233b485 | 338 | add_history_time (const char *string) |
b80f6443 JA |
339 | { |
340 | HIST_ENTRY *hs; | |
341 | ||
ac50fbac | 342 | if (string == 0 || history_length < 1) |
3185942a | 343 | return; |
b80f6443 JA |
344 | hs = the_history[history_length - 1]; |
345 | FREE (hs->timestamp); | |
346 | hs->timestamp = savestring (string); | |
347 | } | |
348 | ||
349 | /* Free HIST and return the data so the calling application can free it | |
350 | if necessary and desired. */ | |
351 | histdata_t | |
d233b485 | 352 | free_history_entry (HIST_ENTRY *hist) |
b80f6443 JA |
353 | { |
354 | histdata_t x; | |
355 | ||
356 | if (hist == 0) | |
357 | return ((histdata_t) 0); | |
358 | FREE (hist->line); | |
359 | FREE (hist->timestamp); | |
360 | x = hist->data; | |
495aee44 | 361 | xfree (hist); |
b80f6443 JA |
362 | return (x); |
363 | } | |
0628567a JA |
364 | |
365 | HIST_ENTRY * | |
d233b485 | 366 | copy_history_entry (HIST_ENTRY *hist) |
0628567a JA |
367 | { |
368 | HIST_ENTRY *ret; | |
369 | char *ts; | |
370 | ||
371 | if (hist == 0) | |
372 | return hist; | |
373 | ||
374 | ret = alloc_history_entry (hist->line, (char *)NULL); | |
375 | ||
376 | ts = hist->timestamp ? savestring (hist->timestamp) : hist->timestamp; | |
377 | ret->timestamp = ts; | |
378 | ||
379 | ret->data = hist->data; | |
380 | ||
381 | return ret; | |
382 | } | |
b80f6443 | 383 | |
726f6388 JA |
384 | /* Make the history entry at WHICH have LINE and DATA. This returns |
385 | the old entry so you can dispose of the data. In the case of an | |
386 | invalid WHICH, a NULL pointer is returned. */ | |
387 | HIST_ENTRY * | |
d233b485 | 388 | replace_history_entry (int which, const char *line, histdata_t data) |
726f6388 | 389 | { |
28ef6c31 | 390 | HIST_ENTRY *temp, *old_value; |
726f6388 | 391 | |
95732b49 | 392 | if (which < 0 || which >= history_length) |
726f6388 JA |
393 | return ((HIST_ENTRY *)NULL); |
394 | ||
28ef6c31 | 395 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); |
726f6388 JA |
396 | old_value = the_history[which]; |
397 | ||
398 | temp->line = savestring (line); | |
399 | temp->data = data; | |
74091dd4 | 400 | temp->timestamp = old_value->timestamp ? savestring (old_value->timestamp) : 0; |
726f6388 JA |
401 | the_history[which] = temp; |
402 | ||
403 | return (old_value); | |
404 | } | |
405 | ||
a0c0a00f CR |
406 | /* Append LINE to the history line at offset WHICH, adding a newline to the |
407 | end of the current line first. This can be used to construct multi-line | |
408 | history entries while reading lines from the history file. */ | |
409 | void | |
d233b485 | 410 | _hs_append_history_line (int which, const char *line) |
a0c0a00f CR |
411 | { |
412 | HIST_ENTRY *hent; | |
d233b485 | 413 | size_t newlen, curlen, minlen; |
a0c0a00f CR |
414 | char *newline; |
415 | ||
416 | hent = the_history[which]; | |
417 | curlen = strlen (hent->line); | |
d233b485 CR |
418 | minlen = curlen + strlen (line) + 2; /* min space needed */ |
419 | if (curlen > 256) /* XXX - for now */ | |
420 | { | |
421 | newlen = 512; /* now realloc in powers of 2 */ | |
422 | /* we recalcluate every time; the operations are cheap */ | |
423 | while (newlen < minlen) | |
424 | newlen <<= 1; | |
425 | } | |
426 | else | |
427 | newlen = minlen; | |
428 | /* Assume that realloc returns the same pointer and doesn't try a new | |
429 | alloc/copy if the new size is the same as the one last passed. */ | |
a0c0a00f CR |
430 | newline = realloc (hent->line, newlen); |
431 | if (newline) | |
432 | { | |
433 | hent->line = newline; | |
434 | hent->line[curlen++] = '\n'; | |
435 | strcpy (hent->line + curlen, line); | |
436 | } | |
437 | } | |
438 | ||
0628567a JA |
439 | /* Replace the DATA in the specified history entries, replacing OLD with |
440 | NEW. WHICH says which one(s) to replace: WHICH == -1 means to replace | |
441 | all of the history entries where entry->data == OLD; WHICH == -2 means | |
442 | to replace the `newest' history entry where entry->data == OLD; and | |
443 | WHICH >= 0 means to replace that particular history entry's data, as | |
444 | long as it matches OLD. */ | |
445 | void | |
d233b485 | 446 | _hs_replace_history_data (int which, histdata_t *old, histdata_t *new) |
0628567a JA |
447 | { |
448 | HIST_ENTRY *entry; | |
449 | register int i, last; | |
450 | ||
451 | if (which < -2 || which >= history_length || history_length == 0 || the_history == 0) | |
452 | return; | |
453 | ||
454 | if (which >= 0) | |
455 | { | |
456 | entry = the_history[which]; | |
457 | if (entry && entry->data == old) | |
458 | entry->data = new; | |
459 | return; | |
460 | } | |
461 | ||
462 | last = -1; | |
463 | for (i = 0; i < history_length; i++) | |
464 | { | |
465 | entry = the_history[i]; | |
466 | if (entry == 0) | |
467 | continue; | |
468 | if (entry->data == old) | |
469 | { | |
470 | last = i; | |
471 | if (which == -1) | |
472 | entry->data = new; | |
473 | } | |
474 | } | |
475 | if (which == -2 && last >= 0) | |
476 | { | |
477 | entry = the_history[last]; | |
478 | entry->data = new; /* XXX - we don't check entry->old */ | |
479 | } | |
480 | } | |
481 | ||
726f6388 JA |
482 | /* Remove history element WHICH from the history. The removed |
483 | element is returned to you so you can free the line, data, | |
484 | and containing structure. */ | |
485 | HIST_ENTRY * | |
d233b485 | 486 | remove_history (int which) |
726f6388 JA |
487 | { |
488 | HIST_ENTRY *return_value; | |
28ef6c31 | 489 | register int i; |
d233b485 CR |
490 | #if 1 |
491 | int nentries; | |
492 | HIST_ENTRY **start, **end; | |
493 | #endif | |
726f6388 | 494 | |
95732b49 JA |
495 | if (which < 0 || which >= history_length || history_length == 0 || the_history == 0) |
496 | return ((HIST_ENTRY *)NULL); | |
726f6388 | 497 | |
95732b49 | 498 | return_value = the_history[which]; |
726f6388 | 499 | |
d233b485 CR |
500 | #if 1 |
501 | /* Copy the rest of the entries, moving down one slot. Copy includes | |
502 | trailing NULL. */ | |
503 | nentries = history_length - which; | |
504 | start = the_history + which; | |
505 | end = start + 1; | |
506 | memmove (start, end, nentries * sizeof (HIST_ENTRY *)); | |
507 | #else | |
95732b49 JA |
508 | for (i = which; i < history_length; i++) |
509 | the_history[i] = the_history[i + 1]; | |
d233b485 | 510 | #endif |
95732b49 JA |
511 | |
512 | history_length--; | |
726f6388 JA |
513 | |
514 | return (return_value); | |
515 | } | |
516 | ||
d233b485 CR |
517 | HIST_ENTRY ** |
518 | remove_history_range (int first, int last) | |
519 | { | |
520 | HIST_ENTRY **return_value; | |
521 | register int i; | |
522 | int nentries; | |
523 | HIST_ENTRY **start, **end; | |
524 | ||
525 | if (the_history == 0 || history_length == 0) | |
526 | return ((HIST_ENTRY **)NULL); | |
527 | if (first < 0 || first >= history_length || last < 0 || last >= history_length) | |
528 | return ((HIST_ENTRY **)NULL); | |
529 | if (first > last) | |
530 | return (HIST_ENTRY **)NULL; | |
531 | ||
532 | nentries = last - first + 1; | |
533 | return_value = (HIST_ENTRY **)malloc ((nentries + 1) * sizeof (HIST_ENTRY *)); | |
534 | if (return_value == 0) | |
535 | return return_value; | |
536 | ||
537 | /* Return all the deleted entries in a list */ | |
538 | for (i = first ; i <= last; i++) | |
539 | return_value[i - first] = the_history[i]; | |
540 | return_value[i - first] = (HIST_ENTRY *)NULL; | |
541 | ||
542 | /* Copy the rest of the entries, moving down NENTRIES slots. Copy includes | |
543 | trailing NULL. */ | |
544 | start = the_history + first; | |
545 | end = the_history + last + 1; | |
546 | memmove (start, end, (history_length - last) * sizeof (HIST_ENTRY *)); | |
547 | ||
548 | history_length -= nentries; | |
549 | ||
550 | return (return_value); | |
551 | } | |
552 | ||
726f6388 JA |
553 | /* Stifle the history list, remembering only MAX number of lines. */ |
554 | void | |
d233b485 | 555 | stifle_history (int max) |
726f6388 | 556 | { |
28ef6c31 JA |
557 | register int i, j; |
558 | ||
726f6388 JA |
559 | if (max < 0) |
560 | max = 0; | |
561 | ||
562 | if (history_length > max) | |
563 | { | |
726f6388 | 564 | /* This loses because we cannot free the data. */ |
ccc6cda3 | 565 | for (i = 0, j = history_length - max; i < j; i++) |
b80f6443 | 566 | free_history_entry (the_history[i]); |
726f6388 JA |
567 | |
568 | history_base = i; | |
569 | for (j = 0, i = history_length - max; j < max; i++, j++) | |
570 | the_history[j] = the_history[i]; | |
571 | the_history[j] = (HIST_ENTRY *)NULL; | |
572 | history_length = j; | |
573 | } | |
574 | ||
575 | history_stifled = 1; | |
28ef6c31 | 576 | max_input_history = history_max_entries = max; |
726f6388 JA |
577 | } |
578 | ||
7117c2d2 JA |
579 | /* Stop stifling the history. This returns the previous maximum |
580 | number of history entries. The value is positive if the history | |
3185942a | 581 | was stifled, negative if it wasn't. */ |
726f6388 | 582 | int |
d233b485 | 583 | unstifle_history (void) |
726f6388 | 584 | { |
726f6388 JA |
585 | if (history_stifled) |
586 | { | |
726f6388 | 587 | history_stifled = 0; |
7117c2d2 | 588 | return (history_max_entries); |
726f6388 | 589 | } |
7117c2d2 JA |
590 | else |
591 | return (-history_max_entries); | |
726f6388 JA |
592 | } |
593 | ||
594 | int | |
d233b485 | 595 | history_is_stifled (void) |
726f6388 JA |
596 | { |
597 | return (history_stifled); | |
598 | } | |
599 | ||
ccc6cda3 | 600 | void |
d233b485 | 601 | clear_history (void) |
726f6388 JA |
602 | { |
603 | register int i; | |
726f6388 | 604 | |
ccc6cda3 JA |
605 | /* This loses because we cannot free the data. */ |
606 | for (i = 0; i < history_length; i++) | |
726f6388 | 607 | { |
b80f6443 | 608 | free_history_entry (the_history[i]); |
ccc6cda3 | 609 | the_history[i] = (HIST_ENTRY *)NULL; |
726f6388 JA |
610 | } |
611 | ||
ccc6cda3 | 612 | history_offset = history_length = 0; |
d233b485 | 613 | history_base = 1; /* reset history base to default */ |
726f6388 | 614 | } |