| 1 | /* history.c -- standalone history library */ |
| 2 | |
| 3 | /* Copyright (C) 1989-2005 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 | static char *hist_inittime PARAMS((void)); |
| 56 | |
| 57 | /* **************************************************************** */ |
| 58 | /* */ |
| 59 | /* History Functions */ |
| 60 | /* */ |
| 61 | /* **************************************************************** */ |
| 62 | |
| 63 | /* An array of HIST_ENTRY. This is where we store the history. */ |
| 64 | static HIST_ENTRY **the_history = (HIST_ENTRY **)NULL; |
| 65 | |
| 66 | /* Non-zero means that we have enforced a limit on the amount of |
| 67 | history that we save. */ |
| 68 | static int history_stifled; |
| 69 | |
| 70 | /* The current number of slots allocated to the input_history. */ |
| 71 | static int history_size; |
| 72 | |
| 73 | /* If HISTORY_STIFLED is non-zero, then this is the maximum number of |
| 74 | entries to remember. */ |
| 75 | int history_max_entries; |
| 76 | int max_input_history; /* backwards compatibility */ |
| 77 | |
| 78 | /* The current location of the interactive history pointer. Just makes |
| 79 | life easier for outside callers. */ |
| 80 | int history_offset; |
| 81 | |
| 82 | /* The number of strings currently stored in the history list. */ |
| 83 | int history_length; |
| 84 | |
| 85 | /* The logical `base' of the history array. It defaults to 1. */ |
| 86 | int history_base = 1; |
| 87 | |
| 88 | /* Return the current HISTORY_STATE of the history. */ |
| 89 | HISTORY_STATE * |
| 90 | history_get_history_state () |
| 91 | { |
| 92 | HISTORY_STATE *state; |
| 93 | |
| 94 | state = (HISTORY_STATE *)xmalloc (sizeof (HISTORY_STATE)); |
| 95 | state->entries = the_history; |
| 96 | state->offset = history_offset; |
| 97 | state->length = history_length; |
| 98 | state->size = history_size; |
| 99 | state->flags = 0; |
| 100 | if (history_stifled) |
| 101 | state->flags |= HS_STIFLED; |
| 102 | |
| 103 | return (state); |
| 104 | } |
| 105 | |
| 106 | /* Set the state of the current history array to STATE. */ |
| 107 | void |
| 108 | history_set_history_state (state) |
| 109 | HISTORY_STATE *state; |
| 110 | { |
| 111 | the_history = state->entries; |
| 112 | history_offset = state->offset; |
| 113 | history_length = state->length; |
| 114 | history_size = state->size; |
| 115 | if (state->flags & HS_STIFLED) |
| 116 | history_stifled = 1; |
| 117 | } |
| 118 | |
| 119 | /* Begin a session in which the history functions might be used. This |
| 120 | initializes interactive variables. */ |
| 121 | void |
| 122 | using_history () |
| 123 | { |
| 124 | history_offset = history_length; |
| 125 | } |
| 126 | |
| 127 | /* Return the number of bytes that the primary history entries are using. |
| 128 | This just adds up the lengths of the_history->lines and the associated |
| 129 | timestamps. */ |
| 130 | int |
| 131 | history_total_bytes () |
| 132 | { |
| 133 | register int i, result; |
| 134 | |
| 135 | for (i = result = 0; the_history && the_history[i]; i++) |
| 136 | result += HISTENT_BYTES (the_history[i]); |
| 137 | |
| 138 | return (result); |
| 139 | } |
| 140 | |
| 141 | /* Returns the magic number which says what history element we are |
| 142 | looking at now. In this implementation, it returns history_offset. */ |
| 143 | int |
| 144 | where_history () |
| 145 | { |
| 146 | return (history_offset); |
| 147 | } |
| 148 | |
| 149 | /* Make the current history item be the one at POS, an absolute index. |
| 150 | Returns zero if POS is out of range, else non-zero. */ |
| 151 | int |
| 152 | history_set_pos (pos) |
| 153 | int pos; |
| 154 | { |
| 155 | if (pos > history_length || pos < 0 || !the_history) |
| 156 | return (0); |
| 157 | history_offset = pos; |
| 158 | return (1); |
| 159 | } |
| 160 | |
| 161 | /* Return the current history array. The caller has to be carefull, since this |
| 162 | is the actual array of data, and could be bashed or made corrupt easily. |
| 163 | The array is terminated with a NULL pointer. */ |
| 164 | HIST_ENTRY ** |
| 165 | history_list () |
| 166 | { |
| 167 | return (the_history); |
| 168 | } |
| 169 | |
| 170 | /* Return the history entry at the current position, as determined by |
| 171 | history_offset. If there is no entry there, return a NULL pointer. */ |
| 172 | HIST_ENTRY * |
| 173 | current_history () |
| 174 | { |
| 175 | return ((history_offset == history_length) || the_history == 0) |
| 176 | ? (HIST_ENTRY *)NULL |
| 177 | : the_history[history_offset]; |
| 178 | } |
| 179 | |
| 180 | /* Back up history_offset to the previous history entry, and return |
| 181 | a pointer to that entry. If there is no previous entry then return |
| 182 | a NULL pointer. */ |
| 183 | HIST_ENTRY * |
| 184 | previous_history () |
| 185 | { |
| 186 | return history_offset ? the_history[--history_offset] : (HIST_ENTRY *)NULL; |
| 187 | } |
| 188 | |
| 189 | /* Move history_offset forward to the next history entry, and return |
| 190 | a pointer to that entry. If there is no next entry then return a |
| 191 | NULL pointer. */ |
| 192 | HIST_ENTRY * |
| 193 | next_history () |
| 194 | { |
| 195 | return (history_offset == history_length) ? (HIST_ENTRY *)NULL : the_history[++history_offset]; |
| 196 | } |
| 197 | |
| 198 | /* Return the history entry which is logically at OFFSET in the history array. |
| 199 | OFFSET is relative to history_base. */ |
| 200 | HIST_ENTRY * |
| 201 | history_get (offset) |
| 202 | int offset; |
| 203 | { |
| 204 | int local_index; |
| 205 | |
| 206 | local_index = offset - history_base; |
| 207 | return (local_index >= history_length || local_index < 0 || the_history == 0) |
| 208 | ? (HIST_ENTRY *)NULL |
| 209 | : the_history[local_index]; |
| 210 | } |
| 211 | |
| 212 | time_t |
| 213 | history_get_time (hist) |
| 214 | HIST_ENTRY *hist; |
| 215 | { |
| 216 | char *ts; |
| 217 | time_t t; |
| 218 | |
| 219 | if (hist == 0 || hist->timestamp == 0) |
| 220 | return 0; |
| 221 | ts = hist->timestamp; |
| 222 | if (ts[0] != history_comment_char) |
| 223 | return 0; |
| 224 | t = (time_t) atol (ts + 1); /* XXX - should use strtol() here */ |
| 225 | return t; |
| 226 | } |
| 227 | |
| 228 | static char * |
| 229 | hist_inittime () |
| 230 | { |
| 231 | time_t t; |
| 232 | char ts[64], *ret; |
| 233 | |
| 234 | t = (time_t) time ((time_t *)0); |
| 235 | #if defined (HAVE_VSNPRINTF) /* assume snprintf if vsnprintf exists */ |
| 236 | snprintf (ts, sizeof (ts) - 1, "X%lu", (unsigned long) t); |
| 237 | #else |
| 238 | sprintf (ts, "X%lu", (unsigned long) t); |
| 239 | #endif |
| 240 | ret = savestring (ts); |
| 241 | ret[0] = history_comment_char; |
| 242 | |
| 243 | return ret; |
| 244 | } |
| 245 | |
| 246 | /* Place STRING at the end of the history list. The data field |
| 247 | is set to NULL. */ |
| 248 | void |
| 249 | add_history (string) |
| 250 | const char *string; |
| 251 | { |
| 252 | HIST_ENTRY *temp; |
| 253 | |
| 254 | if (history_stifled && (history_length == history_max_entries)) |
| 255 | { |
| 256 | register int i; |
| 257 | |
| 258 | /* If the history is stifled, and history_length is zero, |
| 259 | and it equals history_max_entries, we don't save items. */ |
| 260 | if (history_length == 0) |
| 261 | return; |
| 262 | |
| 263 | /* If there is something in the slot, then remove it. */ |
| 264 | if (the_history[0]) |
| 265 | (void) free_history_entry (the_history[0]); |
| 266 | |
| 267 | /* Copy the rest of the entries, moving down one slot. */ |
| 268 | for (i = 0; i < history_length; i++) |
| 269 | the_history[i] = the_history[i + 1]; |
| 270 | |
| 271 | history_base++; |
| 272 | } |
| 273 | else |
| 274 | { |
| 275 | if (history_size == 0) |
| 276 | { |
| 277 | history_size = DEFAULT_HISTORY_GROW_SIZE; |
| 278 | the_history = (HIST_ENTRY **)xmalloc (history_size * sizeof (HIST_ENTRY *)); |
| 279 | history_length = 1; |
| 280 | } |
| 281 | else |
| 282 | { |
| 283 | if (history_length == (history_size - 1)) |
| 284 | { |
| 285 | history_size += DEFAULT_HISTORY_GROW_SIZE; |
| 286 | the_history = (HIST_ENTRY **) |
| 287 | xrealloc (the_history, history_size * sizeof (HIST_ENTRY *)); |
| 288 | } |
| 289 | history_length++; |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); |
| 294 | temp->line = savestring (string); |
| 295 | temp->data = (char *)NULL; |
| 296 | |
| 297 | temp->timestamp = hist_inittime (); |
| 298 | |
| 299 | the_history[history_length] = (HIST_ENTRY *)NULL; |
| 300 | the_history[history_length - 1] = temp; |
| 301 | } |
| 302 | |
| 303 | /* Change the time stamp of the most recent history entry to STRING. */ |
| 304 | void |
| 305 | add_history_time (string) |
| 306 | const char *string; |
| 307 | { |
| 308 | HIST_ENTRY *hs; |
| 309 | |
| 310 | hs = the_history[history_length - 1]; |
| 311 | FREE (hs->timestamp); |
| 312 | hs->timestamp = savestring (string); |
| 313 | } |
| 314 | |
| 315 | /* Free HIST and return the data so the calling application can free it |
| 316 | if necessary and desired. */ |
| 317 | histdata_t |
| 318 | free_history_entry (hist) |
| 319 | HIST_ENTRY *hist; |
| 320 | { |
| 321 | histdata_t x; |
| 322 | |
| 323 | if (hist == 0) |
| 324 | return ((histdata_t) 0); |
| 325 | FREE (hist->line); |
| 326 | FREE (hist->timestamp); |
| 327 | x = hist->data; |
| 328 | free (hist); |
| 329 | return (x); |
| 330 | } |
| 331 | |
| 332 | /* Make the history entry at WHICH have LINE and DATA. This returns |
| 333 | the old entry so you can dispose of the data. In the case of an |
| 334 | invalid WHICH, a NULL pointer is returned. */ |
| 335 | HIST_ENTRY * |
| 336 | replace_history_entry (which, line, data) |
| 337 | int which; |
| 338 | const char *line; |
| 339 | histdata_t data; |
| 340 | { |
| 341 | HIST_ENTRY *temp, *old_value; |
| 342 | |
| 343 | if (which < 0 || which >= history_length) |
| 344 | return ((HIST_ENTRY *)NULL); |
| 345 | |
| 346 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); |
| 347 | old_value = the_history[which]; |
| 348 | |
| 349 | temp->line = savestring (line); |
| 350 | temp->data = data; |
| 351 | temp->timestamp = savestring (old_value->timestamp); |
| 352 | the_history[which] = temp; |
| 353 | |
| 354 | return (old_value); |
| 355 | } |
| 356 | |
| 357 | /* Remove history element WHICH from the history. The removed |
| 358 | element is returned to you so you can free the line, data, |
| 359 | and containing structure. */ |
| 360 | HIST_ENTRY * |
| 361 | remove_history (which) |
| 362 | int which; |
| 363 | { |
| 364 | HIST_ENTRY *return_value; |
| 365 | register int i; |
| 366 | |
| 367 | if (which < 0 || which >= history_length || history_length == 0 || the_history == 0) |
| 368 | return ((HIST_ENTRY *)NULL); |
| 369 | |
| 370 | return_value = the_history[which]; |
| 371 | |
| 372 | for (i = which; i < history_length; i++) |
| 373 | the_history[i] = the_history[i + 1]; |
| 374 | |
| 375 | history_length--; |
| 376 | |
| 377 | return (return_value); |
| 378 | } |
| 379 | |
| 380 | /* Stifle the history list, remembering only MAX number of lines. */ |
| 381 | void |
| 382 | stifle_history (max) |
| 383 | int max; |
| 384 | { |
| 385 | register int i, j; |
| 386 | |
| 387 | if (max < 0) |
| 388 | max = 0; |
| 389 | |
| 390 | if (history_length > max) |
| 391 | { |
| 392 | /* This loses because we cannot free the data. */ |
| 393 | for (i = 0, j = history_length - max; i < j; i++) |
| 394 | free_history_entry (the_history[i]); |
| 395 | |
| 396 | history_base = i; |
| 397 | for (j = 0, i = history_length - max; j < max; i++, j++) |
| 398 | the_history[j] = the_history[i]; |
| 399 | the_history[j] = (HIST_ENTRY *)NULL; |
| 400 | history_length = j; |
| 401 | } |
| 402 | |
| 403 | history_stifled = 1; |
| 404 | max_input_history = history_max_entries = max; |
| 405 | } |
| 406 | |
| 407 | /* Stop stifling the history. This returns the previous maximum |
| 408 | number of history entries. The value is positive if the history |
| 409 | was stifled, negative if it wasn't. */ |
| 410 | int |
| 411 | unstifle_history () |
| 412 | { |
| 413 | if (history_stifled) |
| 414 | { |
| 415 | history_stifled = 0; |
| 416 | return (history_max_entries); |
| 417 | } |
| 418 | else |
| 419 | return (-history_max_entries); |
| 420 | } |
| 421 | |
| 422 | int |
| 423 | history_is_stifled () |
| 424 | { |
| 425 | return (history_stifled); |
| 426 | } |
| 427 | |
| 428 | void |
| 429 | clear_history () |
| 430 | { |
| 431 | register int i; |
| 432 | |
| 433 | /* This loses because we cannot free the data. */ |
| 434 | for (i = 0; i < history_length; i++) |
| 435 | { |
| 436 | free_history_entry (the_history[i]); |
| 437 | the_history[i] = (HIST_ENTRY *)NULL; |
| 438 | } |
| 439 | |
| 440 | history_offset = history_length = 0; |
| 441 | } |