| 1 | /* history.c -- standalone history library */ |
| 2 | |
| 3 | /* Copyright (C) 1989-2017 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 <errno.h> |
| 47 | |
| 48 | #include "history.h" |
| 49 | #include "histlib.h" |
| 50 | |
| 51 | #include "xmalloc.h" |
| 52 | |
| 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 | |
| 60 | #define MAX_HISTORY_INITIAL_SIZE 8192 |
| 61 | |
| 62 | /* The number of slots to increase the_history by. */ |
| 63 | #define DEFAULT_HISTORY_GROW_SIZE 50 |
| 64 | |
| 65 | static char *hist_inittime PARAMS((void)); |
| 66 | |
| 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. */ |
| 78 | static int history_stifled; |
| 79 | |
| 80 | /* The current number of slots allocated to the input_history. */ |
| 81 | static int history_size; |
| 82 | |
| 83 | /* If HISTORY_STIFLED is non-zero, then this is the maximum number of |
| 84 | entries to remember. */ |
| 85 | int history_max_entries; |
| 86 | int max_input_history; /* backwards compatibility */ |
| 87 | |
| 88 | /* The current location of the interactive history pointer. Just makes |
| 89 | life easier for outside callers. */ |
| 90 | int history_offset; |
| 91 | |
| 92 | /* The number of strings currently stored in the history list. */ |
| 93 | int history_length; |
| 94 | |
| 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 * |
| 100 | history_get_history_state (void) |
| 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 |
| 118 | history_set_history_state (HISTORY_STATE *state) |
| 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 |
| 131 | using_history (void) |
| 132 | { |
| 133 | history_offset = history_length; |
| 134 | } |
| 135 | |
| 136 | /* Return the number of bytes that the primary history entries are using. |
| 137 | This just adds up the lengths of the_history->lines and the associated |
| 138 | timestamps. */ |
| 139 | int |
| 140 | history_total_bytes (void) |
| 141 | { |
| 142 | register int i, result; |
| 143 | |
| 144 | for (i = result = 0; the_history && the_history[i]; i++) |
| 145 | result += HISTENT_BYTES (the_history[i]); |
| 146 | |
| 147 | return (result); |
| 148 | } |
| 149 | |
| 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 |
| 153 | where_history (void) |
| 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 |
| 161 | history_set_pos (int pos) |
| 162 | { |
| 163 | if (pos > history_length || pos < 0 || !the_history) |
| 164 | return (0); |
| 165 | history_offset = pos; |
| 166 | return (1); |
| 167 | } |
| 168 | |
| 169 | /* Return the current history array. The caller has to be careful, since this |
| 170 | is the actual array of data, and could be bashed or made corrupt easily. |
| 171 | The array is terminated with a NULL pointer. */ |
| 172 | HIST_ENTRY ** |
| 173 | history_list (void) |
| 174 | { |
| 175 | return (the_history); |
| 176 | } |
| 177 | |
| 178 | /* Return the history entry at the current position, as determined by |
| 179 | history_offset. If there is no entry there, return a NULL pointer. */ |
| 180 | HIST_ENTRY * |
| 181 | current_history (void) |
| 182 | { |
| 183 | return ((history_offset == history_length) || the_history == 0) |
| 184 | ? (HIST_ENTRY *)NULL |
| 185 | : the_history[history_offset]; |
| 186 | } |
| 187 | |
| 188 | /* Back up history_offset to the previous history entry, and return |
| 189 | a pointer to that entry. If there is no previous entry then return |
| 190 | a NULL pointer. */ |
| 191 | HIST_ENTRY * |
| 192 | previous_history (void) |
| 193 | { |
| 194 | return history_offset ? the_history[--history_offset] : (HIST_ENTRY *)NULL; |
| 195 | } |
| 196 | |
| 197 | /* Move history_offset forward to the next history entry, and return |
| 198 | a pointer to that entry. If there is no next entry then return a |
| 199 | NULL pointer. */ |
| 200 | HIST_ENTRY * |
| 201 | next_history (void) |
| 202 | { |
| 203 | return (history_offset == history_length) ? (HIST_ENTRY *)NULL : the_history[++history_offset]; |
| 204 | } |
| 205 | |
| 206 | /* Return the history entry which is logically at OFFSET in the history array. |
| 207 | OFFSET is relative to history_base. */ |
| 208 | HIST_ENTRY * |
| 209 | history_get (int offset) |
| 210 | { |
| 211 | int local_index; |
| 212 | |
| 213 | local_index = offset - history_base; |
| 214 | return (local_index >= history_length || local_index < 0 || the_history == 0) |
| 215 | ? (HIST_ENTRY *)NULL |
| 216 | : the_history[local_index]; |
| 217 | } |
| 218 | |
| 219 | HIST_ENTRY * |
| 220 | alloc_history_entry (char *string, char *ts) |
| 221 | { |
| 222 | HIST_ENTRY *temp; |
| 223 | |
| 224 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); |
| 225 | |
| 226 | temp->line = string ? savestring (string) : string; |
| 227 | temp->data = (char *)NULL; |
| 228 | temp->timestamp = ts; |
| 229 | |
| 230 | return temp; |
| 231 | } |
| 232 | |
| 233 | time_t |
| 234 | history_get_time (HIST_ENTRY *hist) |
| 235 | { |
| 236 | char *ts; |
| 237 | time_t t; |
| 238 | |
| 239 | if (hist == 0 || hist->timestamp == 0) |
| 240 | return 0; |
| 241 | ts = hist->timestamp; |
| 242 | if (ts[0] != history_comment_char) |
| 243 | return 0; |
| 244 | errno = 0; |
| 245 | t = (time_t) strtol (ts + 1, (char **)NULL, 10); /* XXX - should use strtol() here */ |
| 246 | if (errno == ERANGE) |
| 247 | return (time_t)0; |
| 248 | return t; |
| 249 | } |
| 250 | |
| 251 | static char * |
| 252 | hist_inittime (void) |
| 253 | { |
| 254 | time_t t; |
| 255 | char ts[64], *ret; |
| 256 | |
| 257 | t = (time_t) time ((time_t *)0); |
| 258 | #if defined (HAVE_VSNPRINTF) /* assume snprintf if vsnprintf exists */ |
| 259 | snprintf (ts, sizeof (ts) - 1, "X%lu", (unsigned long) t); |
| 260 | #else |
| 261 | sprintf (ts, "X%lu", (unsigned long) t); |
| 262 | #endif |
| 263 | ret = savestring (ts); |
| 264 | ret[0] = history_comment_char; |
| 265 | |
| 266 | return ret; |
| 267 | } |
| 268 | |
| 269 | /* Place STRING at the end of the history list. The data field |
| 270 | is set to NULL. */ |
| 271 | void |
| 272 | add_history (const char *string) |
| 273 | { |
| 274 | HIST_ENTRY *temp; |
| 275 | int new_length; |
| 276 | |
| 277 | if (history_stifled && (history_length == history_max_entries)) |
| 278 | { |
| 279 | register int i; |
| 280 | |
| 281 | /* If the history is stifled, and history_length is zero, |
| 282 | and it equals history_max_entries, we don't save items. */ |
| 283 | if (history_length == 0) |
| 284 | return; |
| 285 | |
| 286 | /* If there is something in the slot, then remove it. */ |
| 287 | if (the_history[0]) |
| 288 | (void) free_history_entry (the_history[0]); |
| 289 | |
| 290 | /* Copy the rest of the entries, moving down one slot. Copy includes |
| 291 | trailing NULL. */ |
| 292 | memmove (the_history, the_history + 1, history_length * sizeof (HIST_ENTRY *)); |
| 293 | |
| 294 | new_length = history_length; |
| 295 | history_base++; |
| 296 | } |
| 297 | else |
| 298 | { |
| 299 | if (history_size == 0) |
| 300 | { |
| 301 | if (history_stifled && history_max_entries > 0) |
| 302 | history_size = (history_max_entries > MAX_HISTORY_INITIAL_SIZE) |
| 303 | ? MAX_HISTORY_INITIAL_SIZE |
| 304 | : history_max_entries + 2; |
| 305 | else |
| 306 | history_size = DEFAULT_HISTORY_INITIAL_SIZE; |
| 307 | the_history = (HIST_ENTRY **)xmalloc (history_size * sizeof (HIST_ENTRY *)); |
| 308 | new_length = 1; |
| 309 | } |
| 310 | else |
| 311 | { |
| 312 | if (history_length == (history_size - 1)) |
| 313 | { |
| 314 | history_size += DEFAULT_HISTORY_GROW_SIZE; |
| 315 | the_history = (HIST_ENTRY **) |
| 316 | xrealloc (the_history, history_size * sizeof (HIST_ENTRY *)); |
| 317 | } |
| 318 | new_length = history_length + 1; |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | temp = alloc_history_entry ((char *)string, hist_inittime ()); |
| 323 | |
| 324 | the_history[new_length] = (HIST_ENTRY *)NULL; |
| 325 | the_history[new_length - 1] = temp; |
| 326 | history_length = new_length; |
| 327 | } |
| 328 | |
| 329 | /* Change the time stamp of the most recent history entry to STRING. */ |
| 330 | void |
| 331 | add_history_time (const char *string) |
| 332 | { |
| 333 | HIST_ENTRY *hs; |
| 334 | |
| 335 | if (string == 0 || history_length < 1) |
| 336 | return; |
| 337 | hs = the_history[history_length - 1]; |
| 338 | FREE (hs->timestamp); |
| 339 | hs->timestamp = savestring (string); |
| 340 | } |
| 341 | |
| 342 | /* Free HIST and return the data so the calling application can free it |
| 343 | if necessary and desired. */ |
| 344 | histdata_t |
| 345 | free_history_entry (HIST_ENTRY *hist) |
| 346 | { |
| 347 | histdata_t x; |
| 348 | |
| 349 | if (hist == 0) |
| 350 | return ((histdata_t) 0); |
| 351 | FREE (hist->line); |
| 352 | FREE (hist->timestamp); |
| 353 | x = hist->data; |
| 354 | xfree (hist); |
| 355 | return (x); |
| 356 | } |
| 357 | |
| 358 | HIST_ENTRY * |
| 359 | copy_history_entry (HIST_ENTRY *hist) |
| 360 | { |
| 361 | HIST_ENTRY *ret; |
| 362 | char *ts; |
| 363 | |
| 364 | if (hist == 0) |
| 365 | return hist; |
| 366 | |
| 367 | ret = alloc_history_entry (hist->line, (char *)NULL); |
| 368 | |
| 369 | ts = hist->timestamp ? savestring (hist->timestamp) : hist->timestamp; |
| 370 | ret->timestamp = ts; |
| 371 | |
| 372 | ret->data = hist->data; |
| 373 | |
| 374 | return ret; |
| 375 | } |
| 376 | |
| 377 | /* Make the history entry at WHICH have LINE and DATA. This returns |
| 378 | the old entry so you can dispose of the data. In the case of an |
| 379 | invalid WHICH, a NULL pointer is returned. */ |
| 380 | HIST_ENTRY * |
| 381 | replace_history_entry (int which, const char *line, histdata_t data) |
| 382 | { |
| 383 | HIST_ENTRY *temp, *old_value; |
| 384 | |
| 385 | if (which < 0 || which >= history_length) |
| 386 | return ((HIST_ENTRY *)NULL); |
| 387 | |
| 388 | temp = (HIST_ENTRY *)xmalloc (sizeof (HIST_ENTRY)); |
| 389 | old_value = the_history[which]; |
| 390 | |
| 391 | temp->line = savestring (line); |
| 392 | temp->data = data; |
| 393 | temp->timestamp = savestring (old_value->timestamp); |
| 394 | the_history[which] = temp; |
| 395 | |
| 396 | return (old_value); |
| 397 | } |
| 398 | |
| 399 | /* Append LINE to the history line at offset WHICH, adding a newline to the |
| 400 | end of the current line first. This can be used to construct multi-line |
| 401 | history entries while reading lines from the history file. */ |
| 402 | void |
| 403 | _hs_append_history_line (int which, const char *line) |
| 404 | { |
| 405 | HIST_ENTRY *hent; |
| 406 | size_t newlen, curlen, minlen; |
| 407 | char *newline; |
| 408 | |
| 409 | hent = the_history[which]; |
| 410 | curlen = strlen (hent->line); |
| 411 | minlen = curlen + strlen (line) + 2; /* min space needed */ |
| 412 | if (curlen > 256) /* XXX - for now */ |
| 413 | { |
| 414 | newlen = 512; /* now realloc in powers of 2 */ |
| 415 | /* we recalcluate every time; the operations are cheap */ |
| 416 | while (newlen < minlen) |
| 417 | newlen <<= 1; |
| 418 | } |
| 419 | else |
| 420 | newlen = minlen; |
| 421 | /* Assume that realloc returns the same pointer and doesn't try a new |
| 422 | alloc/copy if the new size is the same as the one last passed. */ |
| 423 | newline = realloc (hent->line, newlen); |
| 424 | if (newline) |
| 425 | { |
| 426 | hent->line = newline; |
| 427 | hent->line[curlen++] = '\n'; |
| 428 | strcpy (hent->line + curlen, line); |
| 429 | } |
| 430 | } |
| 431 | |
| 432 | /* Replace the DATA in the specified history entries, replacing OLD with |
| 433 | NEW. WHICH says which one(s) to replace: WHICH == -1 means to replace |
| 434 | all of the history entries where entry->data == OLD; WHICH == -2 means |
| 435 | to replace the `newest' history entry where entry->data == OLD; and |
| 436 | WHICH >= 0 means to replace that particular history entry's data, as |
| 437 | long as it matches OLD. */ |
| 438 | void |
| 439 | _hs_replace_history_data (int which, histdata_t *old, histdata_t *new) |
| 440 | { |
| 441 | HIST_ENTRY *entry; |
| 442 | register int i, last; |
| 443 | |
| 444 | if (which < -2 || which >= history_length || history_length == 0 || the_history == 0) |
| 445 | return; |
| 446 | |
| 447 | if (which >= 0) |
| 448 | { |
| 449 | entry = the_history[which]; |
| 450 | if (entry && entry->data == old) |
| 451 | entry->data = new; |
| 452 | return; |
| 453 | } |
| 454 | |
| 455 | last = -1; |
| 456 | for (i = 0; i < history_length; i++) |
| 457 | { |
| 458 | entry = the_history[i]; |
| 459 | if (entry == 0) |
| 460 | continue; |
| 461 | if (entry->data == old) |
| 462 | { |
| 463 | last = i; |
| 464 | if (which == -1) |
| 465 | entry->data = new; |
| 466 | } |
| 467 | } |
| 468 | if (which == -2 && last >= 0) |
| 469 | { |
| 470 | entry = the_history[last]; |
| 471 | entry->data = new; /* XXX - we don't check entry->old */ |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | /* Remove history element WHICH from the history. The removed |
| 476 | element is returned to you so you can free the line, data, |
| 477 | and containing structure. */ |
| 478 | HIST_ENTRY * |
| 479 | remove_history (int which) |
| 480 | { |
| 481 | HIST_ENTRY *return_value; |
| 482 | register int i; |
| 483 | #if 1 |
| 484 | int nentries; |
| 485 | HIST_ENTRY **start, **end; |
| 486 | #endif |
| 487 | |
| 488 | if (which < 0 || which >= history_length || history_length == 0 || the_history == 0) |
| 489 | return ((HIST_ENTRY *)NULL); |
| 490 | |
| 491 | return_value = the_history[which]; |
| 492 | |
| 493 | #if 1 |
| 494 | /* Copy the rest of the entries, moving down one slot. Copy includes |
| 495 | trailing NULL. */ |
| 496 | nentries = history_length - which; |
| 497 | start = the_history + which; |
| 498 | end = start + 1; |
| 499 | memmove (start, end, nentries * sizeof (HIST_ENTRY *)); |
| 500 | #else |
| 501 | for (i = which; i < history_length; i++) |
| 502 | the_history[i] = the_history[i + 1]; |
| 503 | #endif |
| 504 | |
| 505 | history_length--; |
| 506 | |
| 507 | return (return_value); |
| 508 | } |
| 509 | |
| 510 | HIST_ENTRY ** |
| 511 | remove_history_range (int first, int last) |
| 512 | { |
| 513 | HIST_ENTRY **return_value; |
| 514 | register int i; |
| 515 | int nentries; |
| 516 | HIST_ENTRY **start, **end; |
| 517 | |
| 518 | if (the_history == 0 || history_length == 0) |
| 519 | return ((HIST_ENTRY **)NULL); |
| 520 | if (first < 0 || first >= history_length || last < 0 || last >= history_length) |
| 521 | return ((HIST_ENTRY **)NULL); |
| 522 | if (first > last) |
| 523 | return (HIST_ENTRY **)NULL; |
| 524 | |
| 525 | nentries = last - first + 1; |
| 526 | return_value = (HIST_ENTRY **)malloc ((nentries + 1) * sizeof (HIST_ENTRY *)); |
| 527 | if (return_value == 0) |
| 528 | return return_value; |
| 529 | |
| 530 | /* Return all the deleted entries in a list */ |
| 531 | for (i = first ; i <= last; i++) |
| 532 | return_value[i - first] = the_history[i]; |
| 533 | return_value[i - first] = (HIST_ENTRY *)NULL; |
| 534 | |
| 535 | /* Copy the rest of the entries, moving down NENTRIES slots. Copy includes |
| 536 | trailing NULL. */ |
| 537 | start = the_history + first; |
| 538 | end = the_history + last + 1; |
| 539 | memmove (start, end, (history_length - last) * sizeof (HIST_ENTRY *)); |
| 540 | |
| 541 | history_length -= nentries; |
| 542 | |
| 543 | return (return_value); |
| 544 | } |
| 545 | |
| 546 | /* Stifle the history list, remembering only MAX number of lines. */ |
| 547 | void |
| 548 | stifle_history (int max) |
| 549 | { |
| 550 | register int i, j; |
| 551 | |
| 552 | if (max < 0) |
| 553 | max = 0; |
| 554 | |
| 555 | if (history_length > max) |
| 556 | { |
| 557 | /* This loses because we cannot free the data. */ |
| 558 | for (i = 0, j = history_length - max; i < j; i++) |
| 559 | free_history_entry (the_history[i]); |
| 560 | |
| 561 | history_base = i; |
| 562 | for (j = 0, i = history_length - max; j < max; i++, j++) |
| 563 | the_history[j] = the_history[i]; |
| 564 | the_history[j] = (HIST_ENTRY *)NULL; |
| 565 | history_length = j; |
| 566 | } |
| 567 | |
| 568 | history_stifled = 1; |
| 569 | max_input_history = history_max_entries = max; |
| 570 | } |
| 571 | |
| 572 | /* Stop stifling the history. This returns the previous maximum |
| 573 | number of history entries. The value is positive if the history |
| 574 | was stifled, negative if it wasn't. */ |
| 575 | int |
| 576 | unstifle_history (void) |
| 577 | { |
| 578 | if (history_stifled) |
| 579 | { |
| 580 | history_stifled = 0; |
| 581 | return (history_max_entries); |
| 582 | } |
| 583 | else |
| 584 | return (-history_max_entries); |
| 585 | } |
| 586 | |
| 587 | int |
| 588 | history_is_stifled (void) |
| 589 | { |
| 590 | return (history_stifled); |
| 591 | } |
| 592 | |
| 593 | void |
| 594 | clear_history (void) |
| 595 | { |
| 596 | register int i; |
| 597 | |
| 598 | /* This loses because we cannot free the data. */ |
| 599 | for (i = 0; i < history_length; i++) |
| 600 | { |
| 601 | free_history_entry (the_history[i]); |
| 602 | the_history[i] = (HIST_ENTRY *)NULL; |
| 603 | } |
| 604 | |
| 605 | history_offset = history_length = 0; |
| 606 | history_base = 1; /* reset history base to default */ |
| 607 | } |