xref: /freebsd/contrib/nvi/common/search.c (revision 3e5645b78f476816ca3b5acc28b29bbafbb9c444)
1 /*-
2  * Copyright (c) 1992, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "$Id: search.c,v 10.27 2015/03/13 18:41:35 zy Exp $";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #include <sys/time.h>
19 
20 #include <bitstring.h>
21 #include <ctype.h>
22 #include <errno.h>
23 #include <limits.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 
29 #include "common.h"
30 
31 typedef enum { S_EMPTY, S_EOF, S_NOPREV, S_NOTFOUND, S_SOF, S_WRAP } smsg_t;
32 
33 static void	search_msg(SCR *, smsg_t);
34 static int	search_init(SCR *, dir_t, CHAR_T *, size_t, CHAR_T **, u_int);
35 
36 /*
37  * search_init --
38  *	Set up a search.
39  */
40 static int
41 search_init(
42 	SCR *sp,
43 	dir_t dir,
44 	CHAR_T *ptrn,
45 	size_t plen,
46 	CHAR_T **epp,
47 	u_int flags)
48 {
49 	recno_t lno;
50 	int delim;
51 	CHAR_T *p, *t;
52 
53 	/* If the file is empty, it's a fast search. */
54 	if (sp->lno <= 1) {
55 		if (db_last(sp, &lno))
56 			return (1);
57 		if (lno == 0) {
58 			if (LF_ISSET(SEARCH_MSG))
59 				search_msg(sp, S_EMPTY);
60 			return (1);
61 		}
62 	}
63 
64 	if (LF_ISSET(SEARCH_PARSE)) {		/* Parse the string. */
65 		/*
66 		 * Use the saved pattern if no pattern specified, or if only
67 		 * one or two delimiter characters specified.
68 		 *
69 		 * !!!
70 		 * Historically, only the pattern itself was saved, vi didn't
71 		 * preserve addressing or delta information.
72 		 */
73 		if (ptrn == NULL)
74 			goto prev;
75 		if (plen == 1) {
76 			if (epp != NULL)
77 				*epp = ptrn + 1;
78 			goto prev;
79 		}
80 		if (ptrn[0] == ptrn[1]) {
81 			if (epp != NULL)
82 				*epp = ptrn + 2;
83 
84 			/* Complain if we don't have a previous pattern. */
85 prev:			if (sp->re == NULL) {
86 				search_msg(sp, S_NOPREV);
87 				return (1);
88 			}
89 			/* Re-compile the search pattern if necessary. */
90 			if (!F_ISSET(sp, SC_RE_SEARCH) && re_compile(sp,
91 			    sp->re, sp->re_len, NULL, NULL, &sp->re_c,
92 			    RE_C_SEARCH |
93 			    (LF_ISSET(SEARCH_MSG) ? 0 : RE_C_SILENT)))
94 				return (1);
95 
96 			/* Set the search direction. */
97 			if (LF_ISSET(SEARCH_SET))
98 				sp->searchdir = dir;
99 			return (0);
100 		}
101 
102 		/*
103 		 * Set the delimiter, and move forward to the terminating
104 		 * delimiter, handling escaped delimiters.
105 		 *
106 		 * QUOTING NOTE:
107 		 * Only discard an escape character if it escapes a delimiter.
108 		 */
109 		for (delim = *ptrn, p = t = ++ptrn;; *t++ = *p++) {
110 			if (--plen == 0 || p[0] == delim) {
111 				if (plen != 0)
112 					++p;
113 				break;
114 			}
115 			if (plen > 1 && p[0] == '\\' && p[1] == delim) {
116 				++p;
117 				--plen;
118 			}
119 		}
120 		if (epp != NULL)
121 			*epp = p;
122 
123 		plen = t - ptrn;
124 	}
125 
126 	/* Compile the RE. */
127 	if (re_compile(sp, ptrn, plen, &sp->re, &sp->re_len, &sp->re_c,
128 	    RE_C_SEARCH |
129 	    (LF_ISSET(SEARCH_MSG) ? 0 : RE_C_SILENT) |
130 	    (LF_ISSET(SEARCH_TAG) ? RE_C_TAG : 0) |
131 	    (LF_ISSET(SEARCH_CSCOPE) ? RE_C_CSCOPE : 0)))
132 		return (1);
133 
134 	/* Set the search direction. */
135 	if (LF_ISSET(SEARCH_SET))
136 		sp->searchdir = dir;
137 
138 	return (0);
139 }
140 
141 /*
142  * f_search --
143  *	Do a forward search.
144  *
145  * PUBLIC: int f_search(SCR *,
146  * PUBLIC:    MARK *, MARK *, CHAR_T *, size_t, CHAR_T **, u_int);
147  */
148 int
149 f_search(
150 	SCR *sp,
151 	MARK *fm,
152 	MARK *rm,
153 	CHAR_T *ptrn,
154 	size_t plen,
155 	CHAR_T **eptrn,
156 	u_int flags)
157 {
158 	busy_t btype;
159 	recno_t lno;
160 	regmatch_t match[1];
161 	size_t coff, len;
162 	int cnt, eval, rval, wrapped = 0;
163 	CHAR_T *l;
164 
165 	if (search_init(sp, FORWARD, ptrn, plen, eptrn, flags))
166 		return (1);
167 
168 	if (LF_ISSET(SEARCH_FILE)) {
169 		lno = 1;
170 		coff = 0;
171 	} else {
172 		if (db_get(sp, fm->lno, DBG_FATAL, &l, &len))
173 			return (1);
174 		lno = fm->lno;
175 
176 		/*
177 		 * If doing incremental search, start searching at the previous
178 		 * column, so that we search a minimal distance and still match
179 		 * special patterns, e.g., \< for beginning of a word.
180 		 *
181 		 * Otherwise, start searching immediately after the cursor.  If
182 		 * at the end of the line, start searching on the next line.
183 		 * This is incompatible (read bug fix) with the historic vi --
184 		 * searches for the '$' pattern never moved forward, and the
185 		 * "-t foo" didn't work if the 'f' was the first character in
186 		 * the file.
187 		 */
188 		if (LF_ISSET(SEARCH_INCR)) {
189 			if ((coff = fm->cno) != 0)
190 				--coff;
191 		} else if (fm->cno + 1 >= len) {
192 			coff = 0;
193 			lno = fm->lno + 1;
194 			if (db_get(sp, lno, 0, &l, &len)) {
195 				if (!O_ISSET(sp, O_WRAPSCAN)) {
196 					if (LF_ISSET(SEARCH_MSG))
197 						search_msg(sp, S_EOF);
198 					return (1);
199 				}
200 				lno = 1;
201 				wrapped = 1;
202 			}
203 		} else
204 			coff = fm->cno + 1;
205 	}
206 
207 	btype = BUSY_ON;
208 	for (cnt = INTERRUPT_CHECK, rval = 1;; ++lno, coff = 0) {
209 		if (cnt-- == 0) {
210 			if (INTERRUPTED(sp))
211 				break;
212 			if (LF_ISSET(SEARCH_MSG)) {
213 				search_busy(sp, btype);
214 				btype = BUSY_UPDATE;
215 			}
216 			cnt = INTERRUPT_CHECK;
217 		}
218 		if ((wrapped && lno > fm->lno) || db_get(sp, lno, 0, &l, &len)) {
219 			if (wrapped) {
220 				if (LF_ISSET(SEARCH_MSG))
221 					search_msg(sp, S_NOTFOUND);
222 				break;
223 			}
224 			if (!O_ISSET(sp, O_WRAPSCAN)) {
225 				if (LF_ISSET(SEARCH_MSG))
226 					search_msg(sp, S_EOF);
227 				break;
228 			}
229 			lno = 0;
230 			wrapped = 1;
231 			continue;
232 		}
233 
234 		/* If already at EOL, just keep going. */
235 		if (len != 0 && coff == len)
236 			continue;
237 
238 		/* Set the termination. */
239 		match[0].rm_so = coff;
240 		match[0].rm_eo = len;
241 
242 #if defined(DEBUG) && 0
243 		TRACE(sp, "F search: %lu from %u to %u\n",
244 		    lno, coff, len != 0 ? len - 1 : len);
245 #endif
246 		/* Search the line. */
247 		eval = regexec(&sp->re_c, l, 1, match,
248 		    (match[0].rm_so == 0 ? 0 : REG_NOTBOL) | REG_STARTEND);
249 		if (eval == REG_NOMATCH)
250 			continue;
251 		if (eval != 0) {
252 			if (LF_ISSET(SEARCH_MSG))
253 				re_error(sp, eval, &sp->re_c);
254 			else
255 				(void)sp->gp->scr_bell(sp);
256 			break;
257 		}
258 
259 		/* Warn if the search wrapped. */
260 		if (wrapped && LF_ISSET(SEARCH_WMSG))
261 			search_msg(sp, S_WRAP);
262 
263 #if defined(DEBUG) && 0
264 		TRACE(sp, "F search: %qu to %qu\n",
265 		    match[0].rm_so, match[0].rm_eo);
266 #endif
267 		rm->lno = lno;
268 		rm->cno = match[0].rm_so;
269 
270 		/*
271 		 * If a change command, it's possible to move beyond the end
272 		 * of a line.  Historic vi generally got this wrong (e.g. try
273 		 * "c?$<cr>").  Not all that sure this gets it right, there
274 		 * are lots of strange cases.
275 		 */
276 		if (!LF_ISSET(SEARCH_EOL) && rm->cno >= len)
277 			rm->cno = len != 0 ? len - 1 : 0;
278 
279 		rval = 0;
280 		break;
281 	}
282 
283 	if (LF_ISSET(SEARCH_MSG))
284 		search_busy(sp, BUSY_OFF);
285 	return (rval);
286 }
287 
288 /*
289  * b_search --
290  *	Do a backward search.
291  *
292  * PUBLIC: int b_search(SCR *,
293  * PUBLIC:    MARK *, MARK *, CHAR_T *, size_t, CHAR_T **, u_int);
294  */
295 int
296 b_search(
297 	SCR *sp,
298 	MARK *fm,
299 	MARK *rm,
300 	CHAR_T *ptrn,
301 	size_t plen,
302 	CHAR_T **eptrn,
303 	u_int flags)
304 {
305 	busy_t btype;
306 	recno_t lno;
307 	regmatch_t match[1];
308 	size_t coff, last, len;
309 	int cnt, eval, rval, wrapped;
310 	CHAR_T *l;
311 
312 	if (search_init(sp, BACKWARD, ptrn, plen, eptrn, flags))
313 		return (1);
314 
315 	/*
316 	 * If doing incremental search, set the "starting" position past the
317 	 * current column, so that we search a minimal distance and still
318 	 * match special patterns, e.g., \> for the end of a word.  This is
319 	 * safe when the cursor is at the end of a line because we only use
320 	 * it for comparison with the location of the match.
321 	 *
322 	 * Otherwise, start searching immediately before the cursor.  If in
323 	 * the first column, start search on the previous line.
324 	 */
325 	if (LF_ISSET(SEARCH_INCR)) {
326 		lno = fm->lno;
327 		coff = fm->cno + 1;
328 	} else {
329 		if (fm->cno == 0) {
330 			if (fm->lno == 1 && !O_ISSET(sp, O_WRAPSCAN)) {
331 				if (LF_ISSET(SEARCH_MSG))
332 					search_msg(sp, S_SOF);
333 				return (1);
334 			}
335 			lno = fm->lno - 1;
336 		} else
337 			lno = fm->lno;
338 		coff = fm->cno;
339 	}
340 
341 	btype = BUSY_ON;
342 	for (cnt = INTERRUPT_CHECK, rval = 1, wrapped = 0;; --lno, coff = 0) {
343 		if (cnt-- == 0) {
344 			if (INTERRUPTED(sp))
345 				break;
346 			if (LF_ISSET(SEARCH_MSG)) {
347 				search_busy(sp, btype);
348 				btype = BUSY_UPDATE;
349 			}
350 			cnt = INTERRUPT_CHECK;
351 		}
352 		if ((wrapped && lno < fm->lno) || lno == 0) {
353 			if (wrapped) {
354 				if (LF_ISSET(SEARCH_MSG))
355 					search_msg(sp, S_NOTFOUND);
356 				break;
357 			}
358 			if (!O_ISSET(sp, O_WRAPSCAN)) {
359 				if (LF_ISSET(SEARCH_MSG))
360 					search_msg(sp, S_SOF);
361 				break;
362 			}
363 			if (db_last(sp, &lno))
364 				break;
365 			if (lno == 0) {
366 				if (LF_ISSET(SEARCH_MSG))
367 					search_msg(sp, S_EMPTY);
368 				break;
369 			}
370 			++lno;
371 			wrapped = 1;
372 			continue;
373 		}
374 
375 		if (db_get(sp, lno, 0, &l, &len))
376 			break;
377 
378 		/* Set the termination. */
379 		match[0].rm_so = 0;
380 		match[0].rm_eo = len;
381 
382 #if defined(DEBUG) && 0
383 		TRACE(sp, "B search: %lu from 0 to %qu\n", lno, match[0].rm_eo);
384 #endif
385 		/* Search the line. */
386 		eval = regexec(&sp->re_c, l, 1, match,
387 		    (match[0].rm_eo == len ? 0 : REG_NOTEOL) | REG_STARTEND);
388 		if (eval == REG_NOMATCH)
389 			continue;
390 		if (eval != 0) {
391 			if (LF_ISSET(SEARCH_MSG))
392 				re_error(sp, eval, &sp->re_c);
393 			else
394 				(void)sp->gp->scr_bell(sp);
395 			break;
396 		}
397 
398 		/* Check for a match starting past the cursor. */
399 		if (coff != 0 && match[0].rm_so >= coff)
400 			continue;
401 
402 		/* Warn if the search wrapped. */
403 		if (wrapped && LF_ISSET(SEARCH_WMSG))
404 			search_msg(sp, S_WRAP);
405 
406 #if defined(DEBUG) && 0
407 		TRACE(sp, "B found: %qu to %qu\n",
408 		    match[0].rm_so, match[0].rm_eo);
409 #endif
410 		/*
411 		 * We now have the first match on the line.  Step through the
412 		 * line character by character until find the last acceptable
413 		 * match.  This is painful, we need a better interface to regex
414 		 * to make this work.
415 		 */
416 		for (;;) {
417 			last = match[0].rm_so++;
418 			if (match[0].rm_so >= len)
419 				break;
420 			match[0].rm_eo = len;
421 			eval = regexec(&sp->re_c, l, 1, match,
422 			    (match[0].rm_so == 0 ? 0 : REG_NOTBOL) |
423 			    REG_STARTEND);
424 			if (eval == REG_NOMATCH)
425 				break;
426 			if (eval != 0) {
427 				if (LF_ISSET(SEARCH_MSG))
428 					re_error(sp, eval, &sp->re_c);
429 				else
430 					(void)sp->gp->scr_bell(sp);
431 				goto err;
432 			}
433 			if (coff && match[0].rm_so >= coff)
434 				break;
435 		}
436 		rm->lno = lno;
437 
438 		/* See comment in f_search(). */
439 		if (!LF_ISSET(SEARCH_EOL) && last >= len)
440 			rm->cno = len != 0 ? len - 1 : 0;
441 		else
442 			rm->cno = last;
443 		rval = 0;
444 		break;
445 	}
446 
447 err:	if (LF_ISSET(SEARCH_MSG))
448 		search_busy(sp, BUSY_OFF);
449 	return (rval);
450 }
451 
452 /*
453  * search_msg --
454  *	Display one of the search messages.
455  */
456 static void
457 search_msg(
458 	SCR *sp,
459 	smsg_t msg)
460 {
461 	switch (msg) {
462 	case S_EMPTY:
463 		msgq(sp, M_ERR, "072|File empty; nothing to search");
464 		break;
465 	case S_EOF:
466 		msgq(sp, M_ERR,
467 		    "073|Reached end-of-file without finding the pattern");
468 		break;
469 	case S_NOPREV:
470 		msgq(sp, M_ERR, "074|No previous search pattern");
471 		break;
472 	case S_NOTFOUND:
473 		msgq(sp, M_ERR, "075|Pattern not found");
474 		break;
475 	case S_SOF:
476 		msgq(sp, M_ERR,
477 		    "076|Reached top-of-file without finding the pattern");
478 		break;
479 	case S_WRAP:
480 		msgq(sp, M_ERR, "077|Search wrapped");
481 		break;
482 	default:
483 		abort();
484 	}
485 }
486 
487 /*
488  * search_busy --
489  *	Put up the busy searching message.
490  *
491  * PUBLIC: void search_busy(SCR *, busy_t);
492  */
493 void
494 search_busy(
495 	SCR *sp,
496 	busy_t btype)
497 {
498 	sp->gp->scr_busy(sp, "078|Searching...", btype);
499 }
500