xref: /openbsd/usr.bin/less/search.c (revision d9a51c35)
1 /*
2  * Copyright (C) 1984-2012  Mark Nudelman
3  * Modified for use with illumos by Garrett D'Amore.
4  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
5  *
6  * You may distribute under the terms of either the GNU General Public
7  * License or the Less License, as specified in the README file.
8  *
9  * For more information, see the README file.
10  */
11 
12 /*
13  * Routines to search a file for a pattern.
14  */
15 
16 #include "charset.h"
17 #include "less.h"
18 #include "pattern.h"
19 #include "position.h"
20 
21 #define	MINPOS(a, b)	(((a) < (b)) ? (a) : (b))
22 #define	MAXPOS(a, b)	(((a) > (b)) ? (a) : (b))
23 
24 extern int how_search;
25 extern int caseless;
26 extern int linenums;
27 extern int sc_height;
28 extern int jump_sline;
29 extern int bs_mode;
30 extern int ctldisp;
31 extern int status_col;
32 extern void *const ml_search;
33 extern off_t start_attnpos;
34 extern off_t end_attnpos;
35 extern int utf_mode;
36 extern int screen_trashed;
37 extern int hilite_search;
38 extern int size_linebuf;
39 extern int squished;
40 extern int can_goto_line;
41 static int hide_hilite;
42 static off_t prep_startpos;
43 static off_t prep_endpos;
44 static int is_caseless;
45 static int is_ucase_pattern;
46 
47 struct hilite {
48 	struct hilite *hl_next;
49 	off_t hl_startpos;
50 	off_t hl_endpos;
51 };
52 static struct hilite hilite_anchor = { NULL, -1, -1 };
53 static struct hilite filter_anchor = { NULL, -1, -1 };
54 #define	hl_first	hl_next
55 
56 /*
57  * These are the static variables that represent the "remembered"
58  * search pattern and filter pattern.
59  */
60 struct pattern_info {
61 	regex_t *compiled;
62 	char *text;
63 	int search_type;
64 };
65 
66 #define	info_compiled(info) ((info)->compiled)
67 
68 static struct pattern_info search_info;
69 static struct pattern_info filter_info;
70 
71 /*
72  * Are there any uppercase letters in this string?
73  */
74 static int
is_ucase(char * str)75 is_ucase(char *str)
76 {
77 	wchar_t ch;
78 	int len;
79 
80 	for (; *str != '\0'; str += len) {
81 		if ((len = mbtowc(&ch, str, MB_CUR_MAX)) == -1) {
82 			mbtowc(NULL, NULL, MB_CUR_MAX);
83 			len = 1;
84 		} else if (iswupper(ch))
85 			return (1);
86 	}
87 	return (0);
88 }
89 
90 /*
91  * Compile and save a search pattern.
92  */
93 static int
set_pattern(struct pattern_info * info,char * pattern,int search_type)94 set_pattern(struct pattern_info *info, char *pattern, int search_type)
95 {
96 	if (pattern == NULL)
97 		info->compiled = NULL;
98 	else if (compile_pattern(pattern, search_type, &info->compiled) < 0)
99 		return (-1);
100 	/* Pattern compiled successfully; save the text too. */
101 	free(info->text);
102 	info->text = NULL;
103 	if (pattern != NULL)
104 		info->text = estrdup(pattern);
105 	info->search_type = search_type;
106 
107 	/*
108 	 * Ignore case if -I is set OR
109 	 * -i is set AND the pattern is all lowercase.
110 	 */
111 	is_ucase_pattern = is_ucase(pattern);
112 	if (is_ucase_pattern && caseless != OPT_ONPLUS)
113 		is_caseless = 0;
114 	else
115 		is_caseless = caseless;
116 	return (0);
117 }
118 
119 /*
120  * Discard a saved pattern.
121  */
122 static void
clear_pattern(struct pattern_info * info)123 clear_pattern(struct pattern_info *info)
124 {
125 	free(info->text);
126 	info->text = NULL;
127 	uncompile_pattern(&info->compiled);
128 }
129 
130 /*
131  * Initialize saved pattern to nothing.
132  */
133 static void
init_pattern(struct pattern_info * info)134 init_pattern(struct pattern_info *info)
135 {
136 	info->compiled = NULL;
137 	info->text = NULL;
138 	info->search_type = 0;
139 }
140 
141 /*
142  * Initialize search variables.
143  */
144 void
init_search(void)145 init_search(void)
146 {
147 	init_pattern(&search_info);
148 	init_pattern(&filter_info);
149 }
150 
151 /*
152  * Determine which text conversions to perform before pattern matching.
153  */
154 static int
get_cvt_ops(void)155 get_cvt_ops(void)
156 {
157 	int ops = 0;
158 	if (is_caseless || bs_mode == BS_SPECIAL) {
159 		if (is_caseless)
160 			ops |= CVT_TO_LC;
161 		if (bs_mode == BS_SPECIAL)
162 			ops |= CVT_BS;
163 		if (bs_mode != BS_CONTROL)
164 			ops |= CVT_CRLF;
165 	} else if (bs_mode != BS_CONTROL) {
166 		ops |= CVT_CRLF;
167 	}
168 	if (ctldisp == OPT_ONPLUS)
169 		ops |= CVT_ANSI;
170 	return (ops);
171 }
172 
173 /*
174  * Is there a previous (remembered) search pattern?
175  */
176 static int
prev_pattern(struct pattern_info * info)177 prev_pattern(struct pattern_info *info)
178 {
179 	if ((info->search_type & SRCH_NO_REGEX) == 0)
180 		return (info->compiled != NULL);
181 	return (info->text != NULL);
182 }
183 
184 /*
185  * Repaint the hilites currently displayed on the screen.
186  * Repaint each line which contains highlighted text.
187  * If on==0, force all hilites off.
188  */
189 void
repaint_hilite(int on)190 repaint_hilite(int on)
191 {
192 	int slinenum;
193 	off_t pos;
194 	int save_hide_hilite;
195 
196 	if (squished)
197 		repaint();
198 
199 	save_hide_hilite = hide_hilite;
200 	if (!on) {
201 		if (hide_hilite)
202 			return;
203 		hide_hilite = 1;
204 	}
205 
206 	if (!can_goto_line) {
207 		repaint();
208 		hide_hilite = save_hide_hilite;
209 		return;
210 	}
211 
212 	for (slinenum = TOP; slinenum < TOP + sc_height-1; slinenum++) {
213 		pos = position(slinenum);
214 		if (pos == -1)
215 			continue;
216 		(void) forw_line(pos);
217 		goto_line(slinenum);
218 		put_line();
219 	}
220 	lower_left();
221 	hide_hilite = save_hide_hilite;
222 }
223 
224 /*
225  * Clear the attn hilite.
226  */
227 void
clear_attn(void)228 clear_attn(void)
229 {
230 	int slinenum;
231 	off_t old_start_attnpos;
232 	off_t old_end_attnpos;
233 	off_t pos;
234 	off_t epos;
235 	int moved = 0;
236 
237 	if (start_attnpos == -1)
238 		return;
239 	old_start_attnpos = start_attnpos;
240 	old_end_attnpos = end_attnpos;
241 	start_attnpos = end_attnpos = -1;
242 
243 	if (!can_goto_line) {
244 		repaint();
245 		return;
246 	}
247 	if (squished)
248 		repaint();
249 
250 	for (slinenum = TOP; slinenum < TOP + sc_height-1; slinenum++) {
251 		pos = position(slinenum);
252 		if (pos == -1)
253 			continue;
254 		epos = position(slinenum+1);
255 		if (pos < old_end_attnpos &&
256 		    (epos == -1 || epos > old_start_attnpos)) {
257 			(void) forw_line(pos);
258 			goto_line(slinenum);
259 			put_line();
260 			moved = 1;
261 		}
262 	}
263 	if (moved)
264 		lower_left();
265 }
266 
267 /*
268  * Hide search string highlighting.
269  */
270 void
undo_search(void)271 undo_search(void)
272 {
273 	if (!prev_pattern(&search_info)) {
274 		error("No previous regular expression", NULL);
275 		return;
276 	}
277 	hide_hilite = !hide_hilite;
278 	repaint_hilite(1);
279 }
280 
281 /*
282  * Clear the hilite list.
283  */
284 static void
clr_hlist(struct hilite * anchor)285 clr_hlist(struct hilite *anchor)
286 {
287 	struct hilite *hl;
288 	struct hilite *nexthl;
289 
290 	for (hl = anchor->hl_first; hl != NULL; hl = nexthl) {
291 		nexthl = hl->hl_next;
292 		free(hl);
293 	}
294 	anchor->hl_first = NULL;
295 	prep_startpos = prep_endpos = -1;
296 }
297 
298 void
clr_hilite(void)299 clr_hilite(void)
300 {
301 	clr_hlist(&hilite_anchor);
302 }
303 
304 static void
clr_filter(void)305 clr_filter(void)
306 {
307 	clr_hlist(&filter_anchor);
308 }
309 
310 /*
311  * Should any characters in a specified range be highlighted?
312  */
313 	static int
is_hilited_range(off_t pos,off_t epos)314 is_hilited_range(off_t pos, off_t epos)
315 {
316 	struct hilite *hl;
317 
318 	/*
319 	 * Look at each highlight and see if any part of it falls in the range.
320 	 */
321 	for (hl = hilite_anchor.hl_first; hl != NULL; hl = hl->hl_next) {
322 		if (hl->hl_endpos > pos &&
323 		    (epos == -1 || epos > hl->hl_startpos))
324 			return (1);
325 	}
326 	return (0);
327 }
328 
329 /*
330  * Is a line "filtered" -- that is, should it be hidden?
331  */
332 int
is_filtered(off_t pos)333 is_filtered(off_t pos)
334 {
335 	struct hilite *hl;
336 
337 	if (ch_getflags() & CH_HELPFILE)
338 		return (0);
339 
340 	/*
341 	 * Look at each filter and see if the start position
342 	 * equals the start position of the line.
343 	 */
344 	for (hl = filter_anchor.hl_first; hl != NULL; hl = hl->hl_next) {
345 		if (hl->hl_startpos == pos)
346 			return (1);
347 	}
348 	return (0);
349 }
350 
351 /*
352  * Should any characters in a specified range be highlighted?
353  * If nohide is nonzero, don't consider hide_hilite.
354  */
355 int
is_hilited(off_t pos,off_t epos,int nohide,int * p_matches)356 is_hilited(off_t pos, off_t epos, int nohide, int *p_matches)
357 {
358 	int match;
359 
360 	if (p_matches != NULL)
361 		*p_matches = 0;
362 
363 	if (!status_col &&
364 	    start_attnpos != -1 &&
365 	    pos < end_attnpos &&
366 	    (epos == -1 || epos > start_attnpos))
367 		/*
368 		 * The attn line overlaps this range.
369 		 */
370 		return (1);
371 
372 	match = is_hilited_range(pos, epos);
373 	if (!match)
374 		return (0);
375 
376 	if (p_matches != NULL)
377 		/*
378 		 * Report matches, even if we're hiding highlights.
379 		 */
380 		*p_matches = 1;
381 
382 	if (hilite_search == 0)
383 		/*
384 		 * Not doing highlighting.
385 		 */
386 		return (0);
387 
388 	if (!nohide && hide_hilite)
389 		/*
390 		 * Highlighting is hidden.
391 		 */
392 		return (0);
393 
394 	return (1);
395 }
396 
397 /*
398  * Add a new hilite to a hilite list.
399  */
400 static void
add_hilite(struct hilite * anchor,struct hilite * hl)401 add_hilite(struct hilite *anchor, struct hilite *hl)
402 {
403 	struct hilite *ihl;
404 
405 	/*
406 	 * Hilites are sorted in the list; find where new one belongs.
407 	 * Insert new one after ihl.
408 	 */
409 	for (ihl = anchor; ihl->hl_next != NULL; ihl = ihl->hl_next)
410 	{
411 		if (ihl->hl_next->hl_startpos > hl->hl_startpos)
412 			break;
413 	}
414 
415 	/*
416 	 * Truncate hilite so it doesn't overlap any existing ones
417 	 * above and below it.
418 	 */
419 	if (ihl != anchor)
420 		hl->hl_startpos = MAXPOS(hl->hl_startpos, ihl->hl_endpos);
421 	if (ihl->hl_next != NULL)
422 		hl->hl_endpos = MINPOS(hl->hl_endpos,
423 		    ihl->hl_next->hl_startpos);
424 	if (hl->hl_startpos >= hl->hl_endpos) {
425 		/*
426 		 * Hilite was truncated out of existence.
427 		 */
428 		free(hl);
429 		return;
430 	}
431 	hl->hl_next = ihl->hl_next;
432 	ihl->hl_next = hl;
433 }
434 
435 /*
436  * Highlight every character in a range of displayed characters.
437  */
438 static void
create_hilites(off_t linepos,int start_index,int end_index,int * chpos)439 create_hilites(off_t linepos, int start_index, int end_index, int *chpos)
440 {
441 	struct hilite *hl;
442 	int i;
443 
444 	/* Start the first hilite. */
445 	hl = ecalloc(1, sizeof (struct hilite));
446 	hl->hl_startpos = linepos + chpos[start_index];
447 
448 	/*
449 	 * Step through the displayed chars.
450 	 * If the source position (before cvt) of the char is one more
451 	 * than the source pos of the previous char (the usual case),
452 	 * just increase the size of the current hilite by one.
453 	 * Otherwise (there are backspaces or something involved),
454 	 * finish the current hilite and start a new one.
455 	 */
456 	for (i = start_index+1; i <= end_index; i++) {
457 		if (chpos[i] != chpos[i-1] + 1 || i == end_index) {
458 			hl->hl_endpos = linepos + chpos[i-1] + 1;
459 			add_hilite(&hilite_anchor, hl);
460 			/* Start new hilite unless this is the last char. */
461 			if (i < end_index) {
462 				hl = ecalloc(1, sizeof (struct hilite));
463 				hl->hl_startpos = linepos + chpos[i];
464 			}
465 		}
466 	}
467 }
468 
469 /*
470  * Make a hilite for each string in a physical line which matches
471  * the current pattern.
472  * sp,ep delimit the first match already found.
473  */
474 static void
hilite_line(off_t linepos,char * line,int line_len,int * chpos,char * sp,char * ep)475 hilite_line(off_t linepos, char *line, int line_len, int *chpos,
476     char *sp, char *ep)
477 {
478 	char *searchp;
479 	char *line_end = line + line_len;
480 
481 	/*
482 	 * sp and ep delimit the first match in the line.
483 	 * Mark the corresponding file positions, then
484 	 * look for further matches and mark them.
485 	 * {{ This technique, of calling match_pattern on subsequent
486 	 *    substrings of the line, may mark more than is correct
487 	 *    if the pattern starts with "^".  This bug is fixed
488 	 *    for those regex functions that accept a notbol parameter
489 	 *    (currently POSIX, PCRE and V8-with-regexec2). }}
490 	 */
491 	searchp = line;
492 	do {
493 		if (sp == NULL || ep == NULL)
494 			return;
495 
496 		create_hilites(linepos, (intptr_t)sp - (intptr_t)line,
497 		    (intptr_t)ep - (intptr_t)line, chpos);
498 		/*
499 		 * If we matched more than zero characters,
500 		 * move to the first char after the string we matched.
501 		 * If we matched zero, just move to the next char.
502 		 */
503 		if (ep > searchp)
504 			searchp = ep;
505 		else if (searchp != line_end)
506 			searchp++;
507 		else /* end of line */
508 			break;
509 	} while (match_pattern(info_compiled(&search_info), search_info.text,
510 	    searchp, (intptr_t)line_end - (intptr_t)searchp, &sp, &ep, 1,
511 	    search_info.search_type));
512 }
513 
514 /*
515  * Change the caseless-ness of searches.
516  * Updates the internal search state to reflect a change in the -i flag.
517  */
518 void
chg_caseless(void)519 chg_caseless(void)
520 {
521 	if (!is_ucase_pattern)
522 		/*
523 		 * Pattern did not have uppercase.
524 		 * Just set the search caselessness to the global caselessness.
525 		 */
526 		is_caseless = caseless;
527 	else
528 		/*
529 		 * Pattern did have uppercase.
530 		 * Discard the pattern; we can't change search caselessness now.
531 		 */
532 		clear_pattern(&search_info);
533 }
534 
535 /*
536  * Find matching text which is currently on screen and highlight it.
537  */
538 static void
hilite_screen(void)539 hilite_screen(void)
540 {
541 	struct scrpos scrpos;
542 
543 	get_scrpos(&scrpos);
544 	if (scrpos.pos == -1)
545 		return;
546 	prep_hilite(scrpos.pos, position(BOTTOM_PLUS_ONE), -1);
547 	repaint_hilite(1);
548 }
549 
550 /*
551  * Change highlighting parameters.
552  */
553 void
chg_hilite(void)554 chg_hilite(void)
555 {
556 	/*
557 	 * Erase any highlights currently on screen.
558 	 */
559 	clr_hilite();
560 	hide_hilite = 0;
561 
562 	if (hilite_search == OPT_ONPLUS)
563 		/*
564 		 * Display highlights.
565 		 */
566 		hilite_screen();
567 }
568 
569 /*
570  * Figure out where to start a search.
571  */
572 static off_t
search_pos(int search_type)573 search_pos(int search_type)
574 {
575 	off_t pos;
576 	int linenum;
577 
578 	if (empty_screen()) {
579 		/*
580 		 * Start at the beginning (or end) of the file.
581 		 * The empty_screen() case is mainly for
582 		 * command line initiated searches;
583 		 * for example, "+/xyz" on the command line.
584 		 * Also for multi-file (SRCH_PAST_EOF) searches.
585 		 */
586 		if (search_type & SRCH_FORW) {
587 			pos = ch_zero();
588 		} else {
589 			pos = ch_length();
590 			if (pos == -1) {
591 				(void) ch_end_seek();
592 				pos = ch_length();
593 			}
594 		}
595 		linenum = 0;
596 	} else {
597 		int add_one = 0;
598 
599 		if (how_search == OPT_ON) {
600 			/*
601 			 * Search does not include current screen.
602 			 */
603 			if (search_type & SRCH_FORW)
604 				linenum = BOTTOM_PLUS_ONE;
605 			else
606 				linenum = TOP;
607 		} else if (how_search == OPT_ONPLUS &&
608 		    !(search_type & SRCH_AFTER_TARGET)) {
609 			/*
610 			 * Search includes all of displayed screen.
611 			 */
612 			if (search_type & SRCH_FORW)
613 				linenum = TOP;
614 			else
615 				linenum = BOTTOM_PLUS_ONE;
616 		} else {
617 			/*
618 			 * Search includes the part of current screen beyond
619 			 * the jump target.
620 			 * It starts at the jump target (if searching
621 			 * backwards), or at the jump target plus one
622 			 * (if forwards).
623 			 */
624 			linenum = jump_sline;
625 			if (search_type & SRCH_FORW)
626 				add_one = 1;
627 		}
628 		linenum = adjsline(linenum);
629 		pos = position(linenum);
630 		if (add_one)
631 			pos = forw_raw_line(pos, NULL, NULL);
632 	}
633 
634 	/*
635 	 * If the line is empty, look around for a plausible starting place.
636 	 */
637 	if (search_type & SRCH_FORW) {
638 		while (pos == -1) {
639 			if (++linenum >= sc_height)
640 				break;
641 			pos = position(linenum);
642 		}
643 	} else {
644 		while (pos == -1) {
645 			if (--linenum < 0)
646 				break;
647 			pos = position(linenum);
648 		}
649 	}
650 	return (pos);
651 }
652 
653 /*
654  * Search a subset of the file, specified by start/end position.
655  */
656 static int
search_range(off_t pos,off_t endpos,int search_type,int matches,int maxlines,off_t * plinepos,off_t * pendpos)657 search_range(off_t pos, off_t endpos, int search_type, int matches,
658     int maxlines, off_t *plinepos, off_t *pendpos)
659 {
660 	char *line;
661 	char *cline;
662 	int line_len;
663 	off_t linenum;
664 	char *sp, *ep;
665 	int line_match;
666 	int cvt_ops;
667 	int cvt_len;
668 	int *chpos;
669 	off_t linepos, oldpos;
670 
671 	linenum = find_linenum(pos);
672 	oldpos = pos;
673 	for (;;) {
674 		/*
675 		 * Get lines until we find a matching one or until
676 		 * we hit end-of-file (or beginning-of-file if we're
677 		 * going backwards), or until we hit the end position.
678 		 */
679 		if (abort_sigs()) {
680 			/*
681 			 * A signal aborts the search.
682 			 */
683 			return (-1);
684 		}
685 
686 		if ((endpos != -1 && pos >= endpos) ||
687 		    maxlines == 0) {
688 			/*
689 			 * Reached end position without a match.
690 			 */
691 			if (pendpos != NULL)
692 				*pendpos = pos;
693 			return (matches);
694 		}
695 		if (maxlines > 0)
696 			maxlines--;
697 
698 		if (search_type & SRCH_FORW) {
699 			/*
700 			 * Read the next line, and save the
701 			 * starting position of that line in linepos.
702 			 */
703 			linepos = pos;
704 			pos = forw_raw_line(pos, &line, &line_len);
705 			if (linenum != 0)
706 				linenum++;
707 		} else {
708 			/*
709 			 * Read the previous line and save the
710 			 * starting position of that line in linepos.
711 			 */
712 			pos = back_raw_line(pos, &line, &line_len);
713 			linepos = pos;
714 			if (linenum != 0)
715 				linenum--;
716 		}
717 
718 		if (pos == -1) {
719 			/*
720 			 * Reached EOF/BOF without a match.
721 			 */
722 			if (pendpos != NULL)
723 				*pendpos = oldpos;
724 			return (matches);
725 		}
726 
727 		/*
728 		 * If we're using line numbers, we might as well
729 		 * remember the information we have now (the position
730 		 * and line number of the current line).
731 		 * Don't do it for every line because it slows down
732 		 * the search.  Remember the line number only if
733 		 * we're "far" from the last place we remembered it.
734 		 */
735 		if (linenums && abs((int)(pos - oldpos)) > 2048)
736 			add_lnum(linenum, pos);
737 		oldpos = pos;
738 
739 		if (is_filtered(linepos))
740 			continue;
741 
742 		/*
743 		 * If it's a caseless search, convert the line to lowercase.
744 		 * If we're doing backspace processing, delete backspaces.
745 		 */
746 		cvt_ops = get_cvt_ops();
747 		cvt_len = cvt_length(line_len);
748 		cline = ecalloc(1, cvt_len);
749 		chpos = cvt_alloc_chpos(cvt_len);
750 		cvt_text(cline, line, chpos, &line_len, cvt_ops);
751 
752 		/*
753 		 * Check to see if the line matches the filter pattern.
754 		 * If so, add an entry to the filter list.
755 		 */
756 		if ((search_type & SRCH_FIND_ALL) &&
757 		    prev_pattern(&filter_info)) {
758 			int line_filter =
759 			    match_pattern(info_compiled(&filter_info),
760 			    filter_info.text, cline, line_len, &sp, &ep, 0,
761 			    filter_info.search_type);
762 			if (line_filter) {
763 				struct hilite *hl =
764 				    ecalloc(1, sizeof (struct hilite));
765 				hl->hl_startpos = linepos;
766 				hl->hl_endpos = pos;
767 				add_hilite(&filter_anchor, hl);
768 			}
769 		}
770 
771 		/*
772 		 * Test the next line to see if we have a match.
773 		 * We are successful if we either want a match and got one,
774 		 * or if we want a non-match and got one.
775 		 */
776 		if (prev_pattern(&search_info)) {
777 			line_match = match_pattern(info_compiled(&search_info),
778 			    search_info.text, cline, line_len, &sp, &ep, 0,
779 			    search_type);
780 			if (line_match) {
781 				/*
782 				 * Got a match.
783 				 */
784 				if (search_type & SRCH_FIND_ALL) {
785 					/*
786 					 * We are supposed to find all matches
787 					 * in the range.
788 					 * Just add the matches in this line
789 					 * to the hilite list and keep
790 					 * searching.
791 					 */
792 					hilite_line(linepos, cline, line_len,
793 					    chpos, sp, ep);
794 				} else if (--matches <= 0) {
795 					/*
796 					 * Found the one match we're looking
797 					 * for.  Return it.
798 					 */
799 					if (hilite_search == OPT_ON) {
800 						/*
801 						 * Clear the hilite list and
802 						 * add only
803 						 * the matches in this one line.
804 						 */
805 						clr_hilite();
806 						hilite_line(linepos, cline,
807 						    line_len, chpos, sp, ep);
808 					}
809 					free(cline);
810 					free(chpos);
811 					if (plinepos != NULL)
812 						*plinepos = linepos;
813 					return (0);
814 				}
815 			}
816 		}
817 		free(cline);
818 		free(chpos);
819 	}
820 }
821 
822 /*
823  * search for a pattern in history. If found, compile that pattern.
824  */
825 static int
hist_pattern(int search_type)826 hist_pattern(int search_type)
827 {
828 	char *pattern;
829 
830 	set_mlist(ml_search, 0);
831 	pattern = cmd_lastpattern();
832 	if (pattern == NULL)
833 		return (0);
834 
835 	if (set_pattern(&search_info, pattern, search_type) < 0)
836 		return (0);
837 
838 	if (hilite_search == OPT_ONPLUS && !hide_hilite)
839 		hilite_screen();
840 
841 	return (1);
842 }
843 
844 /*
845  * Search for the n-th occurrence of a specified pattern,
846  * either forward or backward.
847  * Return the number of matches not yet found in this file
848  * (that is, n minus the number of matches found).
849  * Return -1 if the search should be aborted.
850  * Caller may continue the search in another file
851  * if less than n matches are found in this file.
852  */
853 int
search(int search_type,char * pattern,int n)854 search(int search_type, char *pattern, int n)
855 {
856 	off_t pos;
857 
858 	if (pattern == NULL || *pattern == '\0') {
859 		/*
860 		 * A null pattern means use the previously compiled pattern.
861 		 */
862 		search_type |= SRCH_AFTER_TARGET;
863 		if (!prev_pattern(&search_info) && !hist_pattern(search_type)) {
864 			error("No previous regular expression", NULL);
865 			return (-1);
866 		}
867 		if ((search_type & SRCH_NO_REGEX) !=
868 		    (search_info.search_type & SRCH_NO_REGEX)) {
869 			error("Please re-enter search pattern", NULL);
870 			return (-1);
871 		}
872 		if (hilite_search == OPT_ON) {
873 			/*
874 			 * Erase the highlights currently on screen.
875 			 * If the search fails, we'll redisplay them later.
876 			 */
877 			repaint_hilite(0);
878 		}
879 		if (hilite_search == OPT_ONPLUS && hide_hilite) {
880 			/*
881 			 * Highlight any matches currently on screen,
882 			 * before we actually start the search.
883 			 */
884 			hide_hilite = 0;
885 			hilite_screen();
886 		}
887 		hide_hilite = 0;
888 	} else {
889 		/*
890 		 * Compile the pattern.
891 		 */
892 		if (set_pattern(&search_info, pattern, search_type) < 0)
893 			return (-1);
894 		if (hilite_search) {
895 			/*
896 			 * Erase the highlights currently on screen.
897 			 * Also permanently delete them from the hilite list.
898 			 */
899 			repaint_hilite(0);
900 			hide_hilite = 0;
901 			clr_hilite();
902 		}
903 		if (hilite_search == OPT_ONPLUS) {
904 			/*
905 			 * Highlight any matches currently on screen,
906 			 * before we actually start the search.
907 			 */
908 			hilite_screen();
909 		}
910 	}
911 
912 	/*
913 	 * Figure out where to start the search.
914 	 */
915 	pos = search_pos(search_type);
916 	if (pos == -1) {
917 		/*
918 		 * Can't find anyplace to start searching from.
919 		 */
920 		if (search_type & SRCH_PAST_EOF)
921 			return (n);
922 		/* repaint(); -- why was this here? */
923 		error("Nothing to search", NULL);
924 		return (-1);
925 	}
926 
927 	n = search_range(pos, -1, search_type, n, -1, &pos, NULL);
928 	if (n != 0) {
929 		/*
930 		 * Search was unsuccessful.
931 		 */
932 		if (hilite_search == OPT_ON && n > 0)
933 			/*
934 			 * Redisplay old hilites.
935 			 */
936 			repaint_hilite(1);
937 		return (n);
938 	}
939 
940 	if (!(search_type & SRCH_NO_MOVE)) {
941 		/*
942 		 * Go to the matching line.
943 		 */
944 		jump_loc(pos, jump_sline);
945 	}
946 
947 	if (hilite_search == OPT_ON)
948 		/*
949 		 * Display new hilites in the matching line.
950 		 */
951 		repaint_hilite(1);
952 	return (0);
953 }
954 
955 
956 /*
957  * Prepare hilites in a given range of the file.
958  *
959  * The pair (prep_startpos,prep_endpos) delimits a contiguous region
960  * of the file that has been "prepared"; that is, scanned for matches for
961  * the current search pattern, and hilites have been created for such matches.
962  * If prep_startpos == -1, the prep region is empty.
963  * If prep_endpos == -1, the prep region extends to EOF.
964  * prep_hilite asks that the range (spos,epos) be covered by the prep region.
965  */
966 void
prep_hilite(off_t spos,off_t epos,int maxlines)967 prep_hilite(off_t spos, off_t epos, int maxlines)
968 {
969 	off_t nprep_startpos = prep_startpos;
970 	off_t nprep_endpos = prep_endpos;
971 	off_t new_epos;
972 	off_t max_epos;
973 	int result;
974 	int i;
975 
976 /*
977  * Search beyond where we're asked to search, so the prep region covers
978  * more than we need.  Do one big search instead of a bunch of small ones.
979  */
980 #define	SEARCH_MORE (3*size_linebuf)
981 
982 	if (!prev_pattern(&search_info) && !is_filtering())
983 		return;
984 
985 	/*
986 	 * If we're limited to a max number of lines, figure out the
987 	 * file position we should stop at.
988 	 */
989 	if (maxlines < 0) {
990 		max_epos = -1;
991 	} else {
992 		max_epos = spos;
993 		for (i = 0; i < maxlines; i++)
994 			max_epos = forw_raw_line(max_epos, NULL, NULL);
995 	}
996 
997 	/*
998 	 * Find two ranges:
999 	 * The range that we need to search (spos,epos); and the range that
1000 	 * the "prep" region will then cover (nprep_startpos,nprep_endpos).
1001 	 */
1002 
1003 	if (prep_startpos == -1 ||
1004 	    (epos != -1 && epos < prep_startpos) ||
1005 	    spos > prep_endpos) {
1006 		/*
1007 		 * New range is not contiguous with old prep region.
1008 		 * Discard the old prep region and start a new one.
1009 		 */
1010 		clr_hilite();
1011 		clr_filter();
1012 		if (epos != -1)
1013 			epos += SEARCH_MORE;
1014 		nprep_startpos = spos;
1015 	} else {
1016 		/*
1017 		 * New range partially or completely overlaps old prep region.
1018 		 */
1019 		if (epos != -1) {
1020 			if (epos > prep_endpos) {
1021 				/*
1022 				 * New range ends after old prep region.
1023 				 * Extend prep region to end at end of new
1024 				 * range.
1025 				 */
1026 				epos += SEARCH_MORE;
1027 
1028 			} else {
1029 				/*
1030 				 * New range ends within old prep region.
1031 				 * Truncate search to end at start of old prep
1032 				 * region.
1033 				 */
1034 				epos = prep_startpos;
1035 			}
1036 		}
1037 
1038 		if (spos < prep_startpos) {
1039 			/*
1040 			 * New range starts before old prep region.
1041 			 * Extend old prep region backwards to start at
1042 			 * start of new range.
1043 			 */
1044 			if (spos < SEARCH_MORE)
1045 				spos = 0;
1046 			else
1047 				spos -= SEARCH_MORE;
1048 			nprep_startpos = spos;
1049 		} else { /* (spos >= prep_startpos) */
1050 			/*
1051 			 * New range starts within or after old prep region.
1052 			 * Trim search to start at end of old prep region.
1053 			 */
1054 			spos = prep_endpos;
1055 		}
1056 	}
1057 
1058 	if (epos != -1 && max_epos != -1 &&
1059 	    epos > max_epos)
1060 		/*
1061 		 * Don't go past the max position we're allowed.
1062 		 */
1063 		epos = max_epos;
1064 
1065 	if (epos == -1 || epos > spos) {
1066 		int search_type = SRCH_FORW | SRCH_FIND_ALL;
1067 		search_type |= (search_info.search_type & SRCH_NO_REGEX);
1068 		result = search_range(spos, epos, search_type, 0,
1069 		    maxlines, NULL, &new_epos);
1070 		if (result < 0)
1071 			return;
1072 		if (prep_endpos == -1 || new_epos > prep_endpos)
1073 			nprep_endpos = new_epos;
1074 	}
1075 	prep_startpos = nprep_startpos;
1076 	prep_endpos = nprep_endpos;
1077 }
1078 
1079 /*
1080  * Set the pattern to be used for line filtering.
1081  */
1082 void
set_filter_pattern(char * pattern,int search_type)1083 set_filter_pattern(char *pattern, int search_type)
1084 {
1085 	clr_filter();
1086 	if (pattern == NULL || *pattern == '\0')
1087 		clear_pattern(&filter_info);
1088 	else
1089 		(void) set_pattern(&filter_info, pattern, search_type);
1090 	screen_trashed = 1;
1091 }
1092 
1093 /*
1094  * Is there a line filter in effect?
1095  */
1096 int
is_filtering(void)1097 is_filtering(void)
1098 {
1099 	if (ch_getflags() & CH_HELPFILE)
1100 		return (0);
1101 	return (prev_pattern(&filter_info));
1102 }
1103