| 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 |
| 10 | the Free Software Foundation; either version 2, or (at your option) |
| 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, |
| 21 | 59 Temple Place, Suite 330, Boston, MA 02111 USA. */ |
| 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 | |
| 47 | #include "history.h" |
| 48 | #include "histlib.h" |
| 49 | |
| 50 | #include "xmalloc.h" |
| 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 | |
| 68 | /* The current number of slots allocated to the input_history. */ |
| 69 | static int history_size; |
| 70 | |
| 71 | /* If HISTORY_STIFLED is non-zero, then this is the maximum number of |
| 72 | entries to remember. */ |
| 73 | int history_max_entries; |
| 74 | int max_input_history; /* backwards compatibility */ |
| 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 | |
| 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 | |
| 132 | for (i = result = 0; the_history && the_history[i]; i++) |
| 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) |
| 213 | const char *string; |
| 214 | { |
| 215 | HIST_ENTRY *temp; |
| 216 | |
| 217 | if (history_stifled && (history_length == history_max_entries)) |
| 218 | { |
| 219 | register int i; |
| 220 | |
| 221 | /* If the history is stifled, and history_length is zero, |
| 222 | and it equals history_max_entries, we don't save items. */ |
| 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; |
| 273 | const char *line; |
| 274 | histdata_t data; |
| 275 | { |
| 276 | HIST_ENTRY *temp, *old_value; |
| 277 | |
| 278 | if (which >= history_length) |
| 279 | return ((HIST_ENTRY *)NULL); |
| 280 | |
| 281 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); |
| 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; |
| 299 | register int i; |
| 300 | |
| 301 | if (which >= history_length || !history_length) |
| 302 | return_value = (HIST_ENTRY *)NULL; |
| 303 | else |
| 304 | { |
| 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 | { |
| 321 | register int i, j; |
| 322 | |
| 323 | if (max < 0) |
| 324 | max = 0; |
| 325 | |
| 326 | if (history_length > max) |
| 327 | { |
| 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; |
| 343 | max_input_history = history_max_entries = max; |
| 344 | } |
| 345 | |
| 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. */ |
| 349 | int |
| 350 | unstifle_history () |
| 351 | { |
| 352 | if (history_stifled) |
| 353 | { |
| 354 | history_stifled = 0; |
| 355 | return (history_max_entries); |
| 356 | } |
| 357 | else |
| 358 | return (-history_max_entries); |
| 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 | } |