Commit | Line | Data |
---|---|---|
d60d9f65 SS |
1 | /* History.c -- standalone history library */ |
2 | ||
3 | /* Copyright (C) 1989, 1992 Free Software Foundation, Inc. | |
4 | ||
5 | This file contains the GNU History Library (the Library), a set of | |
6 | routines for managing the text of previously typed lines. | |
7 | ||
8 | The Library is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
1b17e766 | 10 | the Free Software Foundation; either version 2, or (at your option) |
d60d9f65 SS |
11 | any later version. |
12 | ||
13 | The Library is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | General Public License for more details. | |
17 | ||
18 | The GNU General Public License is often shipped with GNU software, and | |
19 | is generally kept in a file called COPYING or LICENSE. If you do not | |
20 | have a copy of the license, write to the Free Software Foundation, | |
1b17e766 | 21 | 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ |
d60d9f65 SS |
22 | |
23 | /* The goal is to make the implementation transparent, so that you | |
24 | don't have to know what data types are used, just what functions | |
25 | you can call. I think I have done that. */ | |
26 | #define READLINE_LIBRARY | |
27 | ||
28 | #if defined (HAVE_CONFIG_H) | |
29 | # include <config.h> | |
30 | #endif | |
31 | ||
32 | #include <stdio.h> | |
33 | ||
34 | #if defined (HAVE_STDLIB_H) | |
35 | # include <stdlib.h> | |
36 | #else | |
37 | # include "ansi_stdlib.h" | |
38 | #endif /* HAVE_STDLIB_H */ | |
39 | ||
40 | #if defined (HAVE_UNISTD_H) | |
41 | # ifdef _MINIX | |
42 | # include <sys/types.h> | |
43 | # endif | |
44 | # include <unistd.h> | |
45 | #endif | |
46 | ||
d60d9f65 SS |
47 | #include "history.h" |
48 | #include "histlib.h" | |
49 | ||
1b17e766 | 50 | #include "xmalloc.h" |
d60d9f65 SS |
51 | |
52 | /* The number of slots to increase the_history by. */ | |
53 | #define DEFAULT_HISTORY_GROW_SIZE 50 | |
54 | ||
55 | /* **************************************************************** */ | |
56 | /* */ | |
57 | /* History Functions */ | |
58 | /* */ | |
59 | /* **************************************************************** */ | |
60 | ||
61 | /* An array of HIST_ENTRY. This is where we store the history. */ | |
62 | static HIST_ENTRY **the_history = (HIST_ENTRY **)NULL; | |
63 | ||
64 | /* Non-zero means that we have enforced a limit on the amount of | |
65 | history that we save. */ | |
66 | static int history_stifled; | |
67 | ||
9255ee31 EZ |
68 | /* The current number of slots allocated to the input_history. */ |
69 | static int history_size; | |
70 | ||
d60d9f65 SS |
71 | /* If HISTORY_STIFLED is non-zero, then this is the maximum number of |
72 | entries to remember. */ | |
9255ee31 EZ |
73 | int history_max_entries; |
74 | int max_input_history; /* backwards compatibility */ | |
d60d9f65 SS |
75 | |
76 | /* The current location of the interactive history pointer. Just makes | |
77 | life easier for outside callers. */ | |
78 | int history_offset; | |
79 | ||
80 | /* The number of strings currently stored in the history list. */ | |
81 | int history_length; | |
82 | ||
d60d9f65 SS |
83 | /* The logical `base' of the history array. It defaults to 1. */ |
84 | int history_base = 1; | |
85 | ||
86 | /* Return the current HISTORY_STATE of the history. */ | |
87 | HISTORY_STATE * | |
88 | history_get_history_state () | |
89 | { | |
90 | HISTORY_STATE *state; | |
91 | ||
92 | state = (HISTORY_STATE *)xmalloc (sizeof (HISTORY_STATE)); | |
93 | state->entries = the_history; | |
94 | state->offset = history_offset; | |
95 | state->length = history_length; | |
96 | state->size = history_size; | |
97 | state->flags = 0; | |
98 | if (history_stifled) | |
99 | state->flags |= HS_STIFLED; | |
100 | ||
101 | return (state); | |
102 | } | |
103 | ||
104 | /* Set the state of the current history array to STATE. */ | |
105 | void | |
106 | history_set_history_state (state) | |
107 | HISTORY_STATE *state; | |
108 | { | |
109 | the_history = state->entries; | |
110 | history_offset = state->offset; | |
111 | history_length = state->length; | |
112 | history_size = state->size; | |
113 | if (state->flags & HS_STIFLED) | |
114 | history_stifled = 1; | |
115 | } | |
116 | ||
117 | /* Begin a session in which the history functions might be used. This | |
118 | initializes interactive variables. */ | |
119 | void | |
120 | using_history () | |
121 | { | |
122 | history_offset = history_length; | |
123 | } | |
124 | ||
125 | /* Return the number of bytes that the primary history entries are using. | |
126 | This just adds up the lengths of the_history->lines. */ | |
127 | int | |
128 | history_total_bytes () | |
129 | { | |
130 | register int i, result; | |
131 | ||
9255ee31 | 132 | for (i = result = 0; the_history && the_history[i]; i++) |
d60d9f65 SS |
133 | result += strlen (the_history[i]->line); |
134 | ||
135 | return (result); | |
136 | } | |
137 | ||
138 | /* Returns the magic number which says what history element we are | |
139 | looking at now. In this implementation, it returns history_offset. */ | |
140 | int | |
141 | where_history () | |
142 | { | |
143 | return (history_offset); | |
144 | } | |
145 | ||
146 | /* Make the current history item be the one at POS, an absolute index. | |
147 | Returns zero if POS is out of range, else non-zero. */ | |
148 | int | |
149 | history_set_pos (pos) | |
150 | int pos; | |
151 | { | |
152 | if (pos > history_length || pos < 0 || !the_history) | |
153 | return (0); | |
154 | history_offset = pos; | |
155 | return (1); | |
156 | } | |
157 | ||
158 | /* Return the current history array. The caller has to be carefull, since this | |
159 | is the actual array of data, and could be bashed or made corrupt easily. | |
160 | The array is terminated with a NULL pointer. */ | |
161 | HIST_ENTRY ** | |
162 | history_list () | |
163 | { | |
164 | return (the_history); | |
165 | } | |
166 | ||
167 | /* Return the history entry at the current position, as determined by | |
168 | history_offset. If there is no entry there, return a NULL pointer. */ | |
169 | HIST_ENTRY * | |
170 | current_history () | |
171 | { | |
172 | return ((history_offset == history_length) || the_history == 0) | |
173 | ? (HIST_ENTRY *)NULL | |
174 | : the_history[history_offset]; | |
175 | } | |
176 | ||
177 | /* Back up history_offset to the previous history entry, and return | |
178 | a pointer to that entry. If there is no previous entry then return | |
179 | a NULL pointer. */ | |
180 | HIST_ENTRY * | |
181 | previous_history () | |
182 | { | |
183 | return history_offset ? the_history[--history_offset] : (HIST_ENTRY *)NULL; | |
184 | } | |
185 | ||
186 | /* Move history_offset forward to the next history entry, and return | |
187 | a pointer to that entry. If there is no next entry then return a | |
188 | NULL pointer. */ | |
189 | HIST_ENTRY * | |
190 | next_history () | |
191 | { | |
192 | return (history_offset == history_length) ? (HIST_ENTRY *)NULL : the_history[++history_offset]; | |
193 | } | |
194 | ||
195 | /* Return the history entry which is logically at OFFSET in the history array. | |
196 | OFFSET is relative to history_base. */ | |
197 | HIST_ENTRY * | |
198 | history_get (offset) | |
199 | int offset; | |
200 | { | |
201 | int local_index; | |
202 | ||
203 | local_index = offset - history_base; | |
204 | return (local_index >= history_length || local_index < 0 || !the_history) | |
205 | ? (HIST_ENTRY *)NULL | |
206 | : the_history[local_index]; | |
207 | } | |
208 | ||
209 | /* Place STRING at the end of the history list. The data field | |
210 | is set to NULL. */ | |
211 | void | |
212 | add_history (string) | |
9255ee31 | 213 | const char *string; |
d60d9f65 SS |
214 | { |
215 | HIST_ENTRY *temp; | |
216 | ||
9255ee31 | 217 | if (history_stifled && (history_length == history_max_entries)) |
d60d9f65 SS |
218 | { |
219 | register int i; | |
220 | ||
221 | /* If the history is stifled, and history_length is zero, | |
9255ee31 | 222 | and it equals history_max_entries, we don't save items. */ |
d60d9f65 SS |
223 | if (history_length == 0) |
224 | return; | |
225 | ||
226 | /* If there is something in the slot, then remove it. */ | |
227 | if (the_history[0]) | |
228 | { | |
229 | free (the_history[0]->line); | |
230 | free (the_history[0]); | |
231 | } | |
232 | ||
233 | /* Copy the rest of the entries, moving down one slot. */ | |
234 | for (i = 0; i < history_length; i++) | |
235 | the_history[i] = the_history[i + 1]; | |
236 | ||
237 | history_base++; | |
238 | } | |
239 | else | |
240 | { | |
241 | if (history_size == 0) | |
242 | { | |
243 | history_size = DEFAULT_HISTORY_GROW_SIZE; | |
244 | the_history = (HIST_ENTRY **)xmalloc (history_size * sizeof (HIST_ENTRY *)); | |
245 | history_length = 1; | |
246 | } | |
247 | else | |
248 | { | |
249 | if (history_length == (history_size - 1)) | |
250 | { | |
251 | history_size += DEFAULT_HISTORY_GROW_SIZE; | |
252 | the_history = (HIST_ENTRY **) | |
253 | xrealloc (the_history, history_size * sizeof (HIST_ENTRY *)); | |
254 | } | |
255 | history_length++; | |
256 | } | |
257 | } | |
258 | ||
259 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); | |
260 | temp->line = savestring (string); | |
261 | temp->data = (char *)NULL; | |
262 | ||
263 | the_history[history_length] = (HIST_ENTRY *)NULL; | |
264 | the_history[history_length - 1] = temp; | |
265 | } | |
266 | ||
267 | /* Make the history entry at WHICH have LINE and DATA. This returns | |
268 | the old entry so you can dispose of the data. In the case of an | |
269 | invalid WHICH, a NULL pointer is returned. */ | |
270 | HIST_ENTRY * | |
271 | replace_history_entry (which, line, data) | |
272 | int which; | |
9255ee31 | 273 | const char *line; |
c862e87b | 274 | histdata_t data; |
d60d9f65 | 275 | { |
9255ee31 | 276 | HIST_ENTRY *temp, *old_value; |
d60d9f65 SS |
277 | |
278 | if (which >= history_length) | |
279 | return ((HIST_ENTRY *)NULL); | |
280 | ||
9255ee31 | 281 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); |
d60d9f65 SS |
282 | old_value = the_history[which]; |
283 | ||
284 | temp->line = savestring (line); | |
285 | temp->data = data; | |
286 | the_history[which] = temp; | |
287 | ||
288 | return (old_value); | |
289 | } | |
290 | ||
291 | /* Remove history element WHICH from the history. The removed | |
292 | element is returned to you so you can free the line, data, | |
293 | and containing structure. */ | |
294 | HIST_ENTRY * | |
295 | remove_history (which) | |
296 | int which; | |
297 | { | |
298 | HIST_ENTRY *return_value; | |
9255ee31 | 299 | register int i; |
d60d9f65 SS |
300 | |
301 | if (which >= history_length || !history_length) | |
302 | return_value = (HIST_ENTRY *)NULL; | |
303 | else | |
304 | { | |
d60d9f65 SS |
305 | return_value = the_history[which]; |
306 | ||
307 | for (i = which; i < history_length; i++) | |
308 | the_history[i] = the_history[i + 1]; | |
309 | ||
310 | history_length--; | |
311 | } | |
312 | ||
313 | return (return_value); | |
314 | } | |
315 | ||
316 | /* Stifle the history list, remembering only MAX number of lines. */ | |
317 | void | |
318 | stifle_history (max) | |
319 | int max; | |
320 | { | |
9255ee31 EZ |
321 | register int i, j; |
322 | ||
d60d9f65 SS |
323 | if (max < 0) |
324 | max = 0; | |
325 | ||
326 | if (history_length > max) | |
327 | { | |
d60d9f65 SS |
328 | /* This loses because we cannot free the data. */ |
329 | for (i = 0, j = history_length - max; i < j; i++) | |
330 | { | |
331 | free (the_history[i]->line); | |
332 | free (the_history[i]); | |
333 | } | |
334 | ||
335 | history_base = i; | |
336 | for (j = 0, i = history_length - max; j < max; i++, j++) | |
337 | the_history[j] = the_history[i]; | |
338 | the_history[j] = (HIST_ENTRY *)NULL; | |
339 | history_length = j; | |
340 | } | |
341 | ||
342 | history_stifled = 1; | |
9255ee31 | 343 | max_input_history = history_max_entries = max; |
d60d9f65 SS |
344 | } |
345 | ||
9255ee31 EZ |
346 | /* Stop stifling the history. This returns the previous maximum |
347 | number of history entries. The value is positive if the history | |
348 | was stifled, negative if it wasn't. */ | |
d60d9f65 SS |
349 | int |
350 | unstifle_history () | |
351 | { | |
352 | if (history_stifled) | |
353 | { | |
354 | history_stifled = 0; | |
9255ee31 | 355 | return (history_max_entries); |
d60d9f65 | 356 | } |
9255ee31 EZ |
357 | else |
358 | return (-history_max_entries); | |
d60d9f65 SS |
359 | } |
360 | ||
361 | int | |
362 | history_is_stifled () | |
363 | { | |
364 | return (history_stifled); | |
365 | } | |
366 | ||
367 | void | |
368 | clear_history () | |
369 | { | |
370 | register int i; | |
371 | ||
372 | /* This loses because we cannot free the data. */ | |
373 | for (i = 0; i < history_length; i++) | |
374 | { | |
375 | free (the_history[i]->line); | |
376 | free (the_history[i]); | |
377 | the_history[i] = (HIST_ENTRY *)NULL; | |
378 | } | |
379 | ||
380 | history_offset = history_length = 0; | |
381 | } |