| 1 | /* |
| 2 | * Copyright (c) 1988 Mark Nudleman |
| 3 | * Copyright (c) 1988 Regents of the University of California. |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms are permitted |
| 7 | * provided that the above copyright notice and this paragraph are |
| 8 | * duplicated in all such forms and that any documentation, |
| 9 | * advertising materials, and other materials related to such |
| 10 | * distribution and use acknowledge that the software was developed |
| 11 | * by Mark Nudleman and the University of California, Berkeley. The |
| 12 | * name of Mark Nudleman or the |
| 13 | * University may not be used to endorse or promote products derived |
| 14 | * from this software without specific prior written permission. |
| 15 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| 16 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| 17 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 18 | */ |
| 19 | |
| 20 | #ifndef lint |
| 21 | static char sccsid[] = "@(#)prim.c 5.4 (Berkeley) %G%"; |
| 22 | #endif /* not lint */ |
| 23 | |
| 24 | /* |
| 25 | * Primitives for displaying the file on the screen. |
| 26 | */ |
| 27 | |
| 28 | #include "less.h" |
| 29 | #include "position.h" |
| 30 | |
| 31 | public int hit_eof; /* Keeps track of how many times we hit end of file */ |
| 32 | public int screen_trashed; |
| 33 | |
| 34 | static int squished; |
| 35 | |
| 36 | extern int quiet; |
| 37 | extern int sigs; |
| 38 | extern int how_search; |
| 39 | extern int top_scroll; |
| 40 | extern int back_scroll; |
| 41 | extern int sc_width, sc_height; |
| 42 | extern int quit_at_eof; |
| 43 | extern int caseless; |
| 44 | extern int linenums; |
| 45 | extern int plusoption; |
| 46 | extern char *line; |
| 47 | extern char *first_cmd; |
| 48 | extern int tagoption; |
| 49 | |
| 50 | /* |
| 51 | * Sound the bell to indicate he is trying to move past end of file. |
| 52 | */ |
| 53 | static void |
| 54 | eof_bell() |
| 55 | { |
| 56 | if (quiet == NOT_QUIET) |
| 57 | bell(); |
| 58 | else |
| 59 | vbell(); |
| 60 | } |
| 61 | |
| 62 | /* |
| 63 | * Check to see if the end of file is currently "displayed". |
| 64 | */ |
| 65 | static void |
| 66 | eof_check() |
| 67 | { |
| 68 | POSITION pos; |
| 69 | |
| 70 | if (sigs) |
| 71 | return; |
| 72 | /* |
| 73 | * If the bottom line is empty, we are at EOF. |
| 74 | * If the bottom line ends at the file length, |
| 75 | * we must be just at EOF. |
| 76 | */ |
| 77 | pos = position(BOTTOM_PLUS_ONE); |
| 78 | if (pos == NULL_POSITION || pos == ch_length()) |
| 79 | hit_eof++; |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * If the screen is "squished", repaint it. |
| 84 | * "Squished" means the first displayed line is not at the top |
| 85 | * of the screen; this can happen when we display a short file |
| 86 | * for the first time. |
| 87 | */ |
| 88 | static void |
| 89 | squish_check() |
| 90 | { |
| 91 | if (!squished) |
| 92 | return; |
| 93 | squished = 0; |
| 94 | repaint(); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * Display n lines, scrolling forward, |
| 99 | * starting at position pos in the input file. |
| 100 | * "force" means display the n lines even if we hit end of file. |
| 101 | * "only_last" means display only the last screenful if n > screen size. |
| 102 | */ |
| 103 | static void |
| 104 | forw(n, pos, force, only_last) |
| 105 | register int n; |
| 106 | POSITION pos; |
| 107 | int force; |
| 108 | int only_last; |
| 109 | { |
| 110 | int eof = 0; |
| 111 | int nlines = 0; |
| 112 | int do_repaint; |
| 113 | static int first_time = 1; |
| 114 | |
| 115 | squish_check(); |
| 116 | |
| 117 | /* |
| 118 | * do_repaint tells us not to display anything till the end, |
| 119 | * then just repaint the entire screen. |
| 120 | */ |
| 121 | do_repaint = (only_last && n > sc_height-1); |
| 122 | |
| 123 | if (!do_repaint) |
| 124 | { |
| 125 | if (top_scroll && n >= sc_height - 1) |
| 126 | { |
| 127 | /* |
| 128 | * Start a new screen. |
| 129 | * {{ This is not really desirable if we happen |
| 130 | * to hit eof in the middle of this screen, |
| 131 | * but we don't yet know if that will happen. }} |
| 132 | */ |
| 133 | if (top_scroll == 2) |
| 134 | clear(); |
| 135 | home(); |
| 136 | force = 1; |
| 137 | } else |
| 138 | { |
| 139 | lower_left(); |
| 140 | clear_eol(); |
| 141 | } |
| 142 | |
| 143 | if (pos != position(BOTTOM_PLUS_ONE)) |
| 144 | { |
| 145 | /* |
| 146 | * This is not contiguous with what is |
| 147 | * currently displayed. Clear the screen image |
| 148 | * (position table) and start a new screen. |
| 149 | */ |
| 150 | pos_clear(); |
| 151 | add_forw_pos(pos); |
| 152 | force = 1; |
| 153 | if (top_scroll) |
| 154 | { |
| 155 | if (top_scroll == 2) |
| 156 | clear(); |
| 157 | home(); |
| 158 | } else if (!first_time) |
| 159 | { |
| 160 | putstr("...skipping...\n"); |
| 161 | } |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | while (--n >= 0) |
| 166 | { |
| 167 | /* |
| 168 | * Read the next line of input. |
| 169 | */ |
| 170 | pos = forw_line(pos); |
| 171 | if (pos == NULL_POSITION) |
| 172 | { |
| 173 | /* |
| 174 | * End of file: stop here unless the top line |
| 175 | * is still empty, or "force" is true. |
| 176 | */ |
| 177 | eof = 1; |
| 178 | if (!force && position(TOP) != NULL_POSITION) |
| 179 | break; |
| 180 | line = NULL; |
| 181 | } |
| 182 | /* |
| 183 | * Add the position of the next line to the position table. |
| 184 | * Display the current line on the screen. |
| 185 | */ |
| 186 | add_forw_pos(pos); |
| 187 | nlines++; |
| 188 | if (do_repaint) |
| 189 | continue; |
| 190 | /* |
| 191 | * If this is the first screen displayed and |
| 192 | * we hit an early EOF (i.e. before the requested |
| 193 | * number of lines), we "squish" the display down |
| 194 | * at the bottom of the screen. |
| 195 | * But don't do this if a + option or a -t option |
| 196 | * was given. These options can cause us to |
| 197 | * start the display after the beginning of the file, |
| 198 | * and it is not appropriate to squish in that case. |
| 199 | */ |
| 200 | if (first_time && line == NULL && !top_scroll && |
| 201 | !tagoption && !plusoption) |
| 202 | { |
| 203 | squished = 1; |
| 204 | continue; |
| 205 | } |
| 206 | if (top_scroll == 1) |
| 207 | clear_eol(); |
| 208 | put_line(); |
| 209 | } |
| 210 | |
| 211 | if (eof && !sigs) |
| 212 | hit_eof++; |
| 213 | else |
| 214 | eof_check(); |
| 215 | if (nlines == 0) |
| 216 | eof_bell(); |
| 217 | else if (do_repaint) |
| 218 | repaint(); |
| 219 | first_time = 0; |
| 220 | (void) currline(BOTTOM); |
| 221 | } |
| 222 | |
| 223 | /* |
| 224 | * Display n lines, scrolling backward. |
| 225 | */ |
| 226 | static void |
| 227 | back(n, pos, force, only_last) |
| 228 | register int n; |
| 229 | POSITION pos; |
| 230 | int force; |
| 231 | int only_last; |
| 232 | { |
| 233 | int nlines = 0; |
| 234 | int do_repaint; |
| 235 | |
| 236 | squish_check(); |
| 237 | do_repaint = (n > get_back_scroll() || (only_last && n > sc_height-1)); |
| 238 | hit_eof = 0; |
| 239 | while (--n >= 0) |
| 240 | { |
| 241 | /* |
| 242 | * Get the previous line of input. |
| 243 | */ |
| 244 | pos = back_line(pos); |
| 245 | if (pos == NULL_POSITION) |
| 246 | { |
| 247 | /* |
| 248 | * Beginning of file: stop here unless "force" is true. |
| 249 | */ |
| 250 | if (!force) |
| 251 | break; |
| 252 | line = NULL; |
| 253 | } |
| 254 | /* |
| 255 | * Add the position of the previous line to the position table. |
| 256 | * Display the line on the screen. |
| 257 | */ |
| 258 | add_back_pos(pos); |
| 259 | nlines++; |
| 260 | if (!do_repaint) |
| 261 | { |
| 262 | home(); |
| 263 | add_line(); |
| 264 | put_line(); |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | eof_check(); |
| 269 | if (nlines == 0) |
| 270 | eof_bell(); |
| 271 | else if (do_repaint) |
| 272 | repaint(); |
| 273 | (void) currline(BOTTOM); |
| 274 | } |
| 275 | |
| 276 | /* |
| 277 | * Display n more lines, forward. |
| 278 | * Start just after the line currently displayed at the bottom of the screen. |
| 279 | */ |
| 280 | public void |
| 281 | forward(n, only_last) |
| 282 | int n; |
| 283 | int only_last; |
| 284 | { |
| 285 | POSITION pos; |
| 286 | |
| 287 | if (quit_at_eof && hit_eof) |
| 288 | { |
| 289 | /* |
| 290 | * If the -e flag is set and we're trying to go |
| 291 | * forward from end-of-file, go on to the next file. |
| 292 | */ |
| 293 | next_file(1); |
| 294 | return; |
| 295 | } |
| 296 | |
| 297 | pos = position(BOTTOM_PLUS_ONE); |
| 298 | if (pos == NULL_POSITION) |
| 299 | { |
| 300 | eof_bell(); |
| 301 | hit_eof++; |
| 302 | return; |
| 303 | } |
| 304 | forw(n, pos, 0, only_last); |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * Display n more lines, backward. |
| 309 | * Start just before the line currently displayed at the top of the screen. |
| 310 | */ |
| 311 | public void |
| 312 | backward(n, only_last) |
| 313 | int n; |
| 314 | int only_last; |
| 315 | { |
| 316 | POSITION pos; |
| 317 | |
| 318 | pos = position(TOP); |
| 319 | if (pos == NULL_POSITION) |
| 320 | { |
| 321 | /* |
| 322 | * This will almost never happen, |
| 323 | * because the top line is almost never empty. |
| 324 | */ |
| 325 | eof_bell(); |
| 326 | return; |
| 327 | } |
| 328 | back(n, pos, 0, only_last); |
| 329 | } |
| 330 | |
| 331 | /* |
| 332 | * Repaint the screen, starting from a specified position. |
| 333 | */ |
| 334 | static void |
| 335 | prepaint(pos) |
| 336 | POSITION pos; |
| 337 | { |
| 338 | hit_eof = 0; |
| 339 | forw(sc_height-1, pos, 1, 0); |
| 340 | screen_trashed = 0; |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * Repaint the screen. |
| 345 | */ |
| 346 | public void |
| 347 | repaint() |
| 348 | { |
| 349 | /* |
| 350 | * Start at the line currently at the top of the screen |
| 351 | * and redisplay the screen. |
| 352 | */ |
| 353 | prepaint(position(TOP)); |
| 354 | } |
| 355 | |
| 356 | /* |
| 357 | * Jump to the end of the file. |
| 358 | * It is more convenient to paint the screen backward, |
| 359 | * from the end of the file toward the beginning. |
| 360 | */ |
| 361 | public void |
| 362 | jump_forw() |
| 363 | { |
| 364 | POSITION pos; |
| 365 | |
| 366 | if (ch_end_seek()) |
| 367 | { |
| 368 | error("Cannot seek to end of file"); |
| 369 | return; |
| 370 | } |
| 371 | lastmark(); |
| 372 | pos = ch_tell(); |
| 373 | clear(); |
| 374 | pos_clear(); |
| 375 | add_back_pos(pos); |
| 376 | back(sc_height - 1, pos, 0, 0); |
| 377 | } |
| 378 | |
| 379 | /* |
| 380 | * Jump to line n in the file. |
| 381 | */ |
| 382 | public void |
| 383 | jump_back(n) |
| 384 | register int n; |
| 385 | { |
| 386 | register int c; |
| 387 | int nlines; |
| 388 | |
| 389 | /* |
| 390 | * This is done the slow way, by starting at the beginning |
| 391 | * of the file and counting newlines. |
| 392 | * |
| 393 | * {{ Now that we have line numbering (in linenum.c), |
| 394 | * we could improve on this by starting at the |
| 395 | * nearest known line rather than at the beginning. }} |
| 396 | */ |
| 397 | if (ch_seek((POSITION)0)) |
| 398 | { |
| 399 | /* |
| 400 | * Probably a pipe with beginning of file no longer buffered. |
| 401 | * If he wants to go to line 1, we do the best we can, |
| 402 | * by going to the first line which is still buffered. |
| 403 | */ |
| 404 | if (n <= 1 && ch_beg_seek() == 0) |
| 405 | jump_loc(ch_tell()); |
| 406 | error("Cannot get to beginning of file"); |
| 407 | return; |
| 408 | } |
| 409 | |
| 410 | /* |
| 411 | * Start counting lines. |
| 412 | */ |
| 413 | for (nlines = 1; nlines < n; nlines++) |
| 414 | { |
| 415 | while ((c = ch_forw_get()) != '\n') |
| 416 | if (c == EOI) |
| 417 | { |
| 418 | char message[40]; |
| 419 | (void)sprintf(message, "File has only %d lines", |
| 420 | nlines-1); |
| 421 | error(message); |
| 422 | return; |
| 423 | } |
| 424 | } |
| 425 | |
| 426 | jump_loc(ch_tell()); |
| 427 | } |
| 428 | |
| 429 | /* |
| 430 | * Jump to a specified percentage into the file. |
| 431 | * This is a poor compensation for not being able to |
| 432 | * quickly jump to a specific line number. |
| 433 | */ |
| 434 | public void |
| 435 | jump_percent(percent) |
| 436 | int percent; |
| 437 | { |
| 438 | POSITION pos, len; |
| 439 | register int c; |
| 440 | |
| 441 | /* |
| 442 | * Determine the position in the file |
| 443 | * (the specified percentage of the file's length). |
| 444 | */ |
| 445 | if ((len = ch_length()) == NULL_POSITION) |
| 446 | { |
| 447 | error("Don't know length of file"); |
| 448 | return; |
| 449 | } |
| 450 | pos = (percent * len) / 100; |
| 451 | |
| 452 | /* |
| 453 | * Back up to the beginning of the line. |
| 454 | */ |
| 455 | if (ch_seek(pos) == 0) |
| 456 | { |
| 457 | while ((c = ch_back_get()) != '\n' && c != EOI) |
| 458 | ; |
| 459 | if (c == '\n') |
| 460 | (void) ch_forw_get(); |
| 461 | pos = ch_tell(); |
| 462 | } |
| 463 | jump_loc(pos); |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | * Jump to a specified position in the file. |
| 468 | */ |
| 469 | public void |
| 470 | jump_loc(pos) |
| 471 | POSITION pos; |
| 472 | { |
| 473 | register int nline; |
| 474 | POSITION tpos; |
| 475 | |
| 476 | if ((nline = onscreen(pos)) >= 0) |
| 477 | { |
| 478 | /* |
| 479 | * The line is currently displayed. |
| 480 | * Just scroll there. |
| 481 | */ |
| 482 | forw(nline, position(BOTTOM_PLUS_ONE), 1, 0); |
| 483 | return; |
| 484 | } |
| 485 | |
| 486 | /* |
| 487 | * Line is not on screen. |
| 488 | * Seek to the desired location. |
| 489 | */ |
| 490 | if (ch_seek(pos)) |
| 491 | { |
| 492 | error("Cannot seek to that position"); |
| 493 | return; |
| 494 | } |
| 495 | |
| 496 | /* |
| 497 | * See if the desired line is BEFORE the currently |
| 498 | * displayed screen. If so, then move forward far |
| 499 | * enough so the line we're on will be at the bottom |
| 500 | * of the screen, in order to be able to call back() |
| 501 | * to make the screen scroll backwards & put the line |
| 502 | * at the top of the screen. |
| 503 | * {{ This seems inefficient, but it's not so bad, |
| 504 | * since we can never move forward more than a |
| 505 | * screenful before we stop to redraw the screen. }} |
| 506 | */ |
| 507 | tpos = position(TOP); |
| 508 | if (tpos != NULL_POSITION && pos < tpos) |
| 509 | { |
| 510 | POSITION npos = pos; |
| 511 | /* |
| 512 | * Note that we can't forw_line() past tpos here, |
| 513 | * so there should be no EOI at this stage. |
| 514 | */ |
| 515 | for (nline = 0; npos < tpos && nline < sc_height - 1; nline++) |
| 516 | npos = forw_line(npos); |
| 517 | |
| 518 | if (npos < tpos) |
| 519 | { |
| 520 | /* |
| 521 | * More than a screenful back. |
| 522 | */ |
| 523 | lastmark(); |
| 524 | clear(); |
| 525 | pos_clear(); |
| 526 | add_back_pos(npos); |
| 527 | } |
| 528 | |
| 529 | /* |
| 530 | * Note that back() will repaint() if nline > back_scroll. |
| 531 | */ |
| 532 | back(nline, npos, 1, 0); |
| 533 | return; |
| 534 | } |
| 535 | /* |
| 536 | * Remember where we were; clear and paint the screen. |
| 537 | */ |
| 538 | lastmark(); |
| 539 | prepaint(pos); |
| 540 | } |
| 541 | |
| 542 | /* |
| 543 | * The table of marks. |
| 544 | * A mark is simply a position in the file. |
| 545 | */ |
| 546 | #define NMARKS (27) /* 26 for a-z plus one for quote */ |
| 547 | #define LASTMARK (NMARKS-1) /* For quote */ |
| 548 | static POSITION marks[NMARKS]; |
| 549 | |
| 550 | /* |
| 551 | * Initialize the mark table to show no marks are set. |
| 552 | */ |
| 553 | public void |
| 554 | init_mark() |
| 555 | { |
| 556 | int i; |
| 557 | |
| 558 | for (i = 0; i < NMARKS; i++) |
| 559 | marks[i] = NULL_POSITION; |
| 560 | } |
| 561 | |
| 562 | /* |
| 563 | * See if a mark letter is valid (between a and z). |
| 564 | */ |
| 565 | static int |
| 566 | badmark(c) |
| 567 | int c; |
| 568 | { |
| 569 | if (c < 'a' || c > 'z') |
| 570 | { |
| 571 | error("Choose a letter between 'a' and 'z'"); |
| 572 | return (1); |
| 573 | } |
| 574 | return (0); |
| 575 | } |
| 576 | |
| 577 | /* |
| 578 | * Set a mark. |
| 579 | */ |
| 580 | public void |
| 581 | setmark(c) |
| 582 | int c; |
| 583 | { |
| 584 | if (badmark(c)) |
| 585 | return; |
| 586 | marks[c-'a'] = position(TOP); |
| 587 | } |
| 588 | |
| 589 | public void |
| 590 | lastmark() |
| 591 | { |
| 592 | marks[LASTMARK] = position(TOP); |
| 593 | } |
| 594 | |
| 595 | /* |
| 596 | * Go to a previously set mark. |
| 597 | */ |
| 598 | public void |
| 599 | gomark(c) |
| 600 | int c; |
| 601 | { |
| 602 | POSITION pos; |
| 603 | |
| 604 | if (c == '\'') |
| 605 | pos = marks[LASTMARK]; |
| 606 | else if (badmark(c)) |
| 607 | return; |
| 608 | else |
| 609 | pos = marks[c-'a']; |
| 610 | |
| 611 | if (pos == NULL_POSITION) |
| 612 | error("mark not set"); |
| 613 | else |
| 614 | jump_loc(pos); |
| 615 | } |
| 616 | |
| 617 | /* |
| 618 | * Get the backwards scroll limit. |
| 619 | * Must call this function instead of just using the value of |
| 620 | * back_scroll, because the default case depends on sc_height and |
| 621 | * top_scroll, as well as back_scroll. |
| 622 | */ |
| 623 | public int |
| 624 | get_back_scroll() |
| 625 | { |
| 626 | if (back_scroll >= 0) |
| 627 | return (back_scroll); |
| 628 | if (top_scroll) |
| 629 | return (sc_height - 2); |
| 630 | return (sc_height - 1); |
| 631 | } |
| 632 | |
| 633 | /* |
| 634 | * Search for the n-th occurence of a specified pattern, |
| 635 | * either forward or backward. |
| 636 | */ |
| 637 | public void |
| 638 | search(search_forward, pattern, n, wantmatch) |
| 639 | register int search_forward; |
| 640 | register char *pattern; |
| 641 | register int n; |
| 642 | int wantmatch; |
| 643 | { |
| 644 | POSITION pos, linepos; |
| 645 | register char *p; |
| 646 | register char *q; |
| 647 | int linenum; |
| 648 | int linematch; |
| 649 | #if RECOMP |
| 650 | char *re_comp(); |
| 651 | char *errmsg; |
| 652 | #else |
| 653 | #if REGCMP |
| 654 | char *regcmp(); |
| 655 | static char *cpattern = NULL; |
| 656 | #else |
| 657 | static char lpbuf[100]; |
| 658 | static char *last_pattern = NULL; |
| 659 | char *strcpy(); |
| 660 | #endif |
| 661 | #endif |
| 662 | |
| 663 | if (caseless && pattern != NULL) |
| 664 | { |
| 665 | /* |
| 666 | * For a caseless search, convert any uppercase |
| 667 | * in the pattern to lowercase. |
| 668 | */ |
| 669 | for (p = pattern; *p != '\0'; p++) |
| 670 | if (*p >= 'A' && *p <= 'Z') |
| 671 | *p += 'a' - 'A'; |
| 672 | } |
| 673 | #if RECOMP |
| 674 | |
| 675 | /* |
| 676 | * (re_comp handles a null pattern internally, |
| 677 | * so there is no need to check for a null pattern here.) |
| 678 | */ |
| 679 | if ((errmsg = re_comp(pattern)) != NULL) |
| 680 | { |
| 681 | error(errmsg); |
| 682 | return; |
| 683 | } |
| 684 | #else |
| 685 | #if REGCMP |
| 686 | if (pattern == NULL || *pattern == '\0') |
| 687 | { |
| 688 | /* |
| 689 | * A null pattern means use the previous pattern. |
| 690 | * The compiled previous pattern is in cpattern, so just use it. |
| 691 | */ |
| 692 | if (cpattern == NULL) |
| 693 | { |
| 694 | error("No previous regular expression"); |
| 695 | return; |
| 696 | } |
| 697 | } else |
| 698 | { |
| 699 | /* |
| 700 | * Otherwise compile the given pattern. |
| 701 | */ |
| 702 | char *s; |
| 703 | if ((s = regcmp(pattern, 0)) == NULL) |
| 704 | { |
| 705 | error("Invalid pattern"); |
| 706 | return; |
| 707 | } |
| 708 | if (cpattern != NULL) |
| 709 | free(cpattern); |
| 710 | cpattern = s; |
| 711 | } |
| 712 | #else |
| 713 | if (pattern == NULL || *pattern == '\0') |
| 714 | { |
| 715 | /* |
| 716 | * Null pattern means use the previous pattern. |
| 717 | */ |
| 718 | if (last_pattern == NULL) |
| 719 | { |
| 720 | error("No previous regular expression"); |
| 721 | return; |
| 722 | } |
| 723 | pattern = last_pattern; |
| 724 | } else |
| 725 | { |
| 726 | (void)strcpy(lpbuf, pattern); |
| 727 | last_pattern = lpbuf; |
| 728 | } |
| 729 | #endif |
| 730 | #endif |
| 731 | |
| 732 | /* |
| 733 | * Figure out where to start the search. |
| 734 | */ |
| 735 | |
| 736 | if (position(TOP) == NULL_POSITION) |
| 737 | { |
| 738 | /* |
| 739 | * Nothing is currently displayed. |
| 740 | * Start at the beginning of the file. |
| 741 | * (This case is mainly for first_cmd searches, |
| 742 | * for example, "+/xyz" on the command line.) |
| 743 | */ |
| 744 | pos = (POSITION)0; |
| 745 | } else if (!search_forward) |
| 746 | { |
| 747 | /* |
| 748 | * Backward search: start just before the top line |
| 749 | * displayed on the screen. |
| 750 | */ |
| 751 | pos = position(TOP); |
| 752 | } else if (how_search == 0) |
| 753 | { |
| 754 | /* |
| 755 | * Start at the second real line displayed on the screen. |
| 756 | */ |
| 757 | pos = position(TOP); |
| 758 | do |
| 759 | pos = forw_raw_line(pos); |
| 760 | while (pos < position(TOP+1)); |
| 761 | } else if (how_search == 1) |
| 762 | { |
| 763 | /* |
| 764 | * Start just after the bottom line displayed on the screen. |
| 765 | */ |
| 766 | pos = position(BOTTOM_PLUS_ONE); |
| 767 | } else |
| 768 | { |
| 769 | /* |
| 770 | * Start at the second screen line displayed on the screen. |
| 771 | */ |
| 772 | pos = position(TOP_PLUS_ONE); |
| 773 | } |
| 774 | |
| 775 | if (pos == NULL_POSITION) |
| 776 | { |
| 777 | /* |
| 778 | * Can't find anyplace to start searching from. |
| 779 | */ |
| 780 | error("Nothing to search"); |
| 781 | return; |
| 782 | } |
| 783 | |
| 784 | linenum = find_linenum(pos); |
| 785 | for (;;) |
| 786 | { |
| 787 | /* |
| 788 | * Get lines until we find a matching one or |
| 789 | * until we hit end-of-file (or beginning-of-file |
| 790 | * if we're going backwards). |
| 791 | */ |
| 792 | if (sigs) |
| 793 | /* |
| 794 | * A signal aborts the search. |
| 795 | */ |
| 796 | return; |
| 797 | |
| 798 | if (search_forward) |
| 799 | { |
| 800 | /* |
| 801 | * Read the next line, and save the |
| 802 | * starting position of that line in linepos. |
| 803 | */ |
| 804 | linepos = pos; |
| 805 | pos = forw_raw_line(pos); |
| 806 | if (linenum != 0) |
| 807 | linenum++; |
| 808 | } else |
| 809 | { |
| 810 | /* |
| 811 | * Read the previous line and save the |
| 812 | * starting position of that line in linepos. |
| 813 | */ |
| 814 | pos = back_raw_line(pos); |
| 815 | linepos = pos; |
| 816 | if (linenum != 0) |
| 817 | linenum--; |
| 818 | } |
| 819 | |
| 820 | if (pos == NULL_POSITION) |
| 821 | { |
| 822 | /* |
| 823 | * We hit EOF/BOF without a match. |
| 824 | */ |
| 825 | error("Pattern not found"); |
| 826 | return; |
| 827 | } |
| 828 | |
| 829 | /* |
| 830 | * If we're using line numbers, we might as well |
| 831 | * remember the information we have now (the position |
| 832 | * and line number of the current line). |
| 833 | */ |
| 834 | if (linenums) |
| 835 | add_lnum(linenum, pos); |
| 836 | |
| 837 | if (caseless) |
| 838 | { |
| 839 | /* |
| 840 | * If this is a caseless search, convert |
| 841 | * uppercase in the input line to lowercase. |
| 842 | * While we're at it, remove any backspaces |
| 843 | * along with the preceeding char. |
| 844 | * This allows us to match text which is |
| 845 | * underlined or overstruck. |
| 846 | */ |
| 847 | for (p = q = line; *p != '\0'; p++, q++) |
| 848 | { |
| 849 | if (*p >= 'A' && *p <= 'Z') |
| 850 | /* Convert uppercase to lowercase. */ |
| 851 | *q = *p + 'a' - 'A'; |
| 852 | else if (q > line && *p == '\b') |
| 853 | /* Delete BS and preceeding char. */ |
| 854 | q -= 2; |
| 855 | else |
| 856 | /* Otherwise, just copy. */ |
| 857 | *q = *p; |
| 858 | } |
| 859 | } |
| 860 | |
| 861 | /* |
| 862 | * Test the next line to see if we have a match. |
| 863 | * This is done in a variety of ways, depending |
| 864 | * on what pattern matching functions are available. |
| 865 | */ |
| 866 | #if REGCMP |
| 867 | linematch = (regex(cpattern, line) != NULL); |
| 868 | #else |
| 869 | #if RECOMP |
| 870 | linematch = (re_exec(line) == 1); |
| 871 | #else |
| 872 | linematch = match(pattern, line); |
| 873 | #endif |
| 874 | #endif |
| 875 | /* |
| 876 | * We are successful if wantmatch and linematch are |
| 877 | * both true (want a match and got it), |
| 878 | * or both false (want a non-match and got it). |
| 879 | */ |
| 880 | if (((wantmatch && linematch) || (!wantmatch && !linematch)) && |
| 881 | --n <= 0) |
| 882 | /* |
| 883 | * Found the line. |
| 884 | */ |
| 885 | break; |
| 886 | } |
| 887 | |
| 888 | jump_loc(linepos); |
| 889 | } |
| 890 | |
| 891 | #if (!REGCMP) && (!RECOMP) |
| 892 | /* |
| 893 | * We have neither regcmp() nor re_comp(). |
| 894 | * We use this function to do simple pattern matching. |
| 895 | * It supports no metacharacters like *, etc. |
| 896 | */ |
| 897 | static int |
| 898 | match(pattern, buf) |
| 899 | char *pattern, *buf; |
| 900 | { |
| 901 | register char *pp, *lp; |
| 902 | |
| 903 | for ( ; *buf != '\0'; buf++) |
| 904 | { |
| 905 | for (pp = pattern, lp = buf; *pp == *lp; pp++, lp++) |
| 906 | if (*pp == '\0' || *lp == '\0') |
| 907 | break; |
| 908 | if (*pp == '\0') |
| 909 | return (1); |
| 910 | } |
| 911 | return (0); |
| 912 | } |
| 913 | #endif |