Annotation of embedaddon/readline/history.c, revision 1.1.1.1
1.1 misho 1: /* history.c -- standalone history library */
2:
3: /* Copyright (C) 1989-2011 Free Software Foundation, Inc.
4:
5: This file contains the GNU History Library (History), a set of
6: routines for managing the text of previously typed lines.
7:
8: History is free software: you can redistribute it and/or modify
9: it under the terms of the GNU General Public License as published by
10: the Free Software Foundation, either version 3 of the License, or
11: (at your option) any later version.
12:
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.
17:
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: */
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:
27: #if defined (HAVE_CONFIG_H)
28: # include <config.h>
29: #endif
30:
31: #include <stdio.h>
32:
33: #if defined (HAVE_STDLIB_H)
34: # include <stdlib.h>
35: #else
36: # include "ansi_stdlib.h"
37: #endif /* HAVE_STDLIB_H */
38:
39: #if defined (HAVE_UNISTD_H)
40: # ifdef _MINIX
41: # include <sys/types.h>
42: # endif
43: # include <unistd.h>
44: #endif
45:
46: #include "history.h"
47: #include "histlib.h"
48:
49: #include "xmalloc.h"
50:
51: /* The number of slots to increase the_history by. */
52: #define DEFAULT_HISTORY_GROW_SIZE 50
53:
54: static char *hist_inittime PARAMS((void));
55:
56: /* **************************************************************** */
57: /* */
58: /* History Functions */
59: /* */
60: /* **************************************************************** */
61:
62: /* An array of HIST_ENTRY. This is where we store the history. */
63: static HIST_ENTRY **the_history = (HIST_ENTRY **)NULL;
64:
65: /* Non-zero means that we have enforced a limit on the amount of
66: history that we save. */
67: static int history_stifled;
68:
69: /* The current number of slots allocated to the input_history. */
70: static int history_size;
71:
72: /* If HISTORY_STIFLED is non-zero, then this is the maximum number of
73: entries to remember. */
74: int history_max_entries;
75: int max_input_history; /* backwards compatibility */
76:
77: /* The current location of the interactive history pointer. Just makes
78: life easier for outside callers. */
79: int history_offset;
80:
81: /* The number of strings currently stored in the history list. */
82: int history_length;
83:
84: /* The logical `base' of the history array. It defaults to 1. */
85: int history_base = 1;
86:
87: /* Return the current HISTORY_STATE of the history. */
88: HISTORY_STATE *
89: history_get_history_state ()
90: {
91: HISTORY_STATE *state;
92:
93: state = (HISTORY_STATE *)xmalloc (sizeof (HISTORY_STATE));
94: state->entries = the_history;
95: state->offset = history_offset;
96: state->length = history_length;
97: state->size = history_size;
98: state->flags = 0;
99: if (history_stifled)
100: state->flags |= HS_STIFLED;
101:
102: return (state);
103: }
104:
105: /* Set the state of the current history array to STATE. */
106: void
107: history_set_history_state (state)
108: HISTORY_STATE *state;
109: {
110: the_history = state->entries;
111: history_offset = state->offset;
112: history_length = state->length;
113: history_size = state->size;
114: if (state->flags & HS_STIFLED)
115: history_stifled = 1;
116: }
117:
118: /* Begin a session in which the history functions might be used. This
119: initializes interactive variables. */
120: void
121: using_history ()
122: {
123: history_offset = history_length;
124: }
125:
126: /* Return the number of bytes that the primary history entries are using.
127: This just adds up the lengths of the_history->lines and the associated
128: timestamps. */
129: int
130: history_total_bytes ()
131: {
132: register int i, result;
133:
134: for (i = result = 0; the_history && the_history[i]; i++)
135: result += HISTENT_BYTES (the_history[i]);
136:
137: return (result);
138: }
139:
140: /* Returns the magic number which says what history element we are
141: looking at now. In this implementation, it returns history_offset. */
142: int
143: where_history ()
144: {
145: return (history_offset);
146: }
147:
148: /* Make the current history item be the one at POS, an absolute index.
149: Returns zero if POS is out of range, else non-zero. */
150: int
151: history_set_pos (pos)
152: int pos;
153: {
154: if (pos > history_length || pos < 0 || !the_history)
155: return (0);
156: history_offset = pos;
157: return (1);
158: }
159:
160: /* Return the current history array. The caller has to be careful, since this
161: is the actual array of data, and could be bashed or made corrupt easily.
162: The array is terminated with a NULL pointer. */
163: HIST_ENTRY **
164: history_list ()
165: {
166: return (the_history);
167: }
168:
169: /* Return the history entry at the current position, as determined by
170: history_offset. If there is no entry there, return a NULL pointer. */
171: HIST_ENTRY *
172: current_history ()
173: {
174: return ((history_offset == history_length) || the_history == 0)
175: ? (HIST_ENTRY *)NULL
176: : the_history[history_offset];
177: }
178:
179: /* Back up history_offset to the previous history entry, and return
180: a pointer to that entry. If there is no previous entry then return
181: a NULL pointer. */
182: HIST_ENTRY *
183: previous_history ()
184: {
185: return history_offset ? the_history[--history_offset] : (HIST_ENTRY *)NULL;
186: }
187:
188: /* Move history_offset forward to the next history entry, and return
189: a pointer to that entry. If there is no next entry then return a
190: NULL pointer. */
191: HIST_ENTRY *
192: next_history ()
193: {
194: return (history_offset == history_length) ? (HIST_ENTRY *)NULL : the_history[++history_offset];
195: }
196:
197: /* Return the history entry which is logically at OFFSET in the history array.
198: OFFSET is relative to history_base. */
199: HIST_ENTRY *
200: history_get (offset)
201: int offset;
202: {
203: int local_index;
204:
205: local_index = offset - history_base;
206: return (local_index >= history_length || local_index < 0 || the_history == 0)
207: ? (HIST_ENTRY *)NULL
208: : the_history[local_index];
209: }
210:
211: HIST_ENTRY *
212: alloc_history_entry (string, ts)
213: char *string;
214: char *ts;
215: {
216: HIST_ENTRY *temp;
217:
218: temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY));
219:
220: temp->line = string ? savestring (string) : string;
221: temp->data = (char *)NULL;
222: temp->timestamp = ts;
223:
224: return temp;
225: }
226:
227: time_t
228: history_get_time (hist)
229: HIST_ENTRY *hist;
230: {
231: char *ts;
232: time_t t;
233:
234: if (hist == 0 || hist->timestamp == 0)
235: return 0;
236: ts = hist->timestamp;
237: if (ts[0] != history_comment_char)
238: return 0;
239: t = (time_t) strtol (ts + 1, (char **)NULL, 10); /* XXX - should use strtol() here */
240: return t;
241: }
242:
243: static char *
244: hist_inittime ()
245: {
246: time_t t;
247: char ts[64], *ret;
248:
249: t = (time_t) time ((time_t *)0);
250: #if defined (HAVE_VSNPRINTF) /* assume snprintf if vsnprintf exists */
251: snprintf (ts, sizeof (ts) - 1, "X%lu", (unsigned long) t);
252: #else
253: sprintf (ts, "X%lu", (unsigned long) t);
254: #endif
255: ret = savestring (ts);
256: ret[0] = history_comment_char;
257:
258: return ret;
259: }
260:
261: /* Place STRING at the end of the history list. The data field
262: is set to NULL. */
263: void
264: add_history (string)
265: const char *string;
266: {
267: HIST_ENTRY *temp;
268:
269: if (history_stifled && (history_length == history_max_entries))
270: {
271: register int i;
272:
273: /* If the history is stifled, and history_length is zero,
274: and it equals history_max_entries, we don't save items. */
275: if (history_length == 0)
276: return;
277:
278: /* If there is something in the slot, then remove it. */
279: if (the_history[0])
280: (void) free_history_entry (the_history[0]);
281:
282: /* Copy the rest of the entries, moving down one slot. */
283: for (i = 0; i < history_length; i++)
284: the_history[i] = the_history[i + 1];
285:
286: history_base++;
287: }
288: else
289: {
290: if (history_size == 0)
291: {
292: history_size = DEFAULT_HISTORY_GROW_SIZE;
293: the_history = (HIST_ENTRY **)xmalloc (history_size * sizeof (HIST_ENTRY *));
294: history_length = 1;
295: }
296: else
297: {
298: if (history_length == (history_size - 1))
299: {
300: history_size += DEFAULT_HISTORY_GROW_SIZE;
301: the_history = (HIST_ENTRY **)
302: xrealloc (the_history, history_size * sizeof (HIST_ENTRY *));
303: }
304: history_length++;
305: }
306: }
307:
308: temp = alloc_history_entry (string, hist_inittime ());
309:
310: the_history[history_length] = (HIST_ENTRY *)NULL;
311: the_history[history_length - 1] = temp;
312: }
313:
314: /* Change the time stamp of the most recent history entry to STRING. */
315: void
316: add_history_time (string)
317: const char *string;
318: {
319: HIST_ENTRY *hs;
320:
321: if (string == 0 || history_length < 1)
322: return;
323: hs = the_history[history_length - 1];
324: FREE (hs->timestamp);
325: hs->timestamp = savestring (string);
326: }
327:
328: /* Free HIST and return the data so the calling application can free it
329: if necessary and desired. */
330: histdata_t
331: free_history_entry (hist)
332: HIST_ENTRY *hist;
333: {
334: histdata_t x;
335:
336: if (hist == 0)
337: return ((histdata_t) 0);
338: FREE (hist->line);
339: FREE (hist->timestamp);
340: x = hist->data;
341: xfree (hist);
342: return (x);
343: }
344:
345: HIST_ENTRY *
346: copy_history_entry (hist)
347: HIST_ENTRY *hist;
348: {
349: HIST_ENTRY *ret;
350: char *ts;
351:
352: if (hist == 0)
353: return hist;
354:
355: ret = alloc_history_entry (hist->line, (char *)NULL);
356:
357: ts = hist->timestamp ? savestring (hist->timestamp) : hist->timestamp;
358: ret->timestamp = ts;
359:
360: ret->data = hist->data;
361:
362: return ret;
363: }
364:
365: /* Make the history entry at WHICH have LINE and DATA. This returns
366: the old entry so you can dispose of the data. In the case of an
367: invalid WHICH, a NULL pointer is returned. */
368: HIST_ENTRY *
369: replace_history_entry (which, line, data)
370: int which;
371: const char *line;
372: histdata_t data;
373: {
374: HIST_ENTRY *temp, *old_value;
375:
376: if (which < 0 || which >= history_length)
377: return ((HIST_ENTRY *)NULL);
378:
379: temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY));
380: old_value = the_history[which];
381:
382: temp->line = savestring (line);
383: temp->data = data;
384: temp->timestamp = savestring (old_value->timestamp);
385: the_history[which] = temp;
386:
387: return (old_value);
388: }
389:
390: /* Replace the DATA in the specified history entries, replacing OLD with
391: NEW. WHICH says which one(s) to replace: WHICH == -1 means to replace
392: all of the history entries where entry->data == OLD; WHICH == -2 means
393: to replace the `newest' history entry where entry->data == OLD; and
394: WHICH >= 0 means to replace that particular history entry's data, as
395: long as it matches OLD. */
396: void
397: replace_history_data (which, old, new)
398: int which;
399: histdata_t *old, *new;
400: {
401: HIST_ENTRY *entry;
402: register int i, last;
403:
404: if (which < -2 || which >= history_length || history_length == 0 || the_history == 0)
405: return;
406:
407: if (which >= 0)
408: {
409: entry = the_history[which];
410: if (entry && entry->data == old)
411: entry->data = new;
412: return;
413: }
414:
415: last = -1;
416: for (i = 0; i < history_length; i++)
417: {
418: entry = the_history[i];
419: if (entry == 0)
420: continue;
421: if (entry->data == old)
422: {
423: last = i;
424: if (which == -1)
425: entry->data = new;
426: }
427: }
428: if (which == -2 && last >= 0)
429: {
430: entry = the_history[last];
431: entry->data = new; /* XXX - we don't check entry->old */
432: }
433: }
434:
435: /* Remove history element WHICH from the history. The removed
436: element is returned to you so you can free the line, data,
437: and containing structure. */
438: HIST_ENTRY *
439: remove_history (which)
440: int which;
441: {
442: HIST_ENTRY *return_value;
443: register int i;
444:
445: if (which < 0 || which >= history_length || history_length == 0 || the_history == 0)
446: return ((HIST_ENTRY *)NULL);
447:
448: return_value = the_history[which];
449:
450: for (i = which; i < history_length; i++)
451: the_history[i] = the_history[i + 1];
452:
453: history_length--;
454:
455: return (return_value);
456: }
457:
458: /* Stifle the history list, remembering only MAX number of lines. */
459: void
460: stifle_history (max)
461: int max;
462: {
463: register int i, j;
464:
465: if (max < 0)
466: max = 0;
467:
468: if (history_length > max)
469: {
470: /* This loses because we cannot free the data. */
471: for (i = 0, j = history_length - max; i < j; i++)
472: free_history_entry (the_history[i]);
473:
474: history_base = i;
475: for (j = 0, i = history_length - max; j < max; i++, j++)
476: the_history[j] = the_history[i];
477: the_history[j] = (HIST_ENTRY *)NULL;
478: history_length = j;
479: }
480:
481: history_stifled = 1;
482: max_input_history = history_max_entries = max;
483: }
484:
485: /* Stop stifling the history. This returns the previous maximum
486: number of history entries. The value is positive if the history
487: was stifled, negative if it wasn't. */
488: int
489: unstifle_history ()
490: {
491: if (history_stifled)
492: {
493: history_stifled = 0;
494: return (history_max_entries);
495: }
496: else
497: return (-history_max_entries);
498: }
499:
500: int
501: history_is_stifled ()
502: {
503: return (history_stifled);
504: }
505:
506: void
507: clear_history ()
508: {
509: register int i;
510:
511: /* This loses because we cannot free the data. */
512: for (i = 0; i < history_length; i++)
513: {
514: free_history_entry (the_history[i]);
515: the_history[i] = (HIST_ENTRY *)NULL;
516: }
517:
518: history_offset = history_length = 0;
519: }
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