xref: /freebsd/contrib/nvi/common/search.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/time.h>
15 
16 #include <bitstring.h>
17 #include <ctype.h>
18 #include <errno.h>
19 #include <limits.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 
25 #include "common.h"
26 
27 typedef enum { S_EMPTY, S_EOF, S_NOPREV, S_NOTFOUND, S_SOF, S_WRAP } smsg_t;
28 
29 static void	search_msg(SCR *, smsg_t);
30 static int	search_init(SCR *, dir_t, CHAR_T *, size_t, CHAR_T **, u_int);
31 
32 /*
33  * search_init --
34  *	Set up a search.
35  */
36 static int
37 search_init(SCR *sp, dir_t dir, CHAR_T *ptrn, size_t plen, CHAR_T **epp,
38     u_int flags)
39 {
40 	recno_t lno;
41 	int delim;
42 	CHAR_T *p, *t;
43 
44 	/* If the file is empty, it's a fast search. */
45 	if (sp->lno <= 1) {
46 		if (db_last(sp, &lno))
47 			return (1);
48 		if (lno == 0) {
49 			if (LF_ISSET(SEARCH_MSG))
50 				search_msg(sp, S_EMPTY);
51 			return (1);
52 		}
53 	}
54 
55 	if (LF_ISSET(SEARCH_PARSE)) {		/* Parse the string. */
56 		/*
57 		 * Use the saved pattern if no pattern specified, or if only
58 		 * one or two delimiter characters specified.
59 		 *
60 		 * !!!
61 		 * Historically, only the pattern itself was saved, vi didn't
62 		 * preserve addressing or delta information.
63 		 */
64 		if (ptrn == NULL)
65 			goto prev;
66 		if (plen == 1) {
67 			if (epp != NULL)
68 				*epp = ptrn + 1;
69 			goto prev;
70 		}
71 		if (ptrn[0] == ptrn[1]) {
72 			if (epp != NULL)
73 				*epp = ptrn + 2;
74 
75 			/* Complain if we don't have a previous pattern. */
76 prev:			if (sp->re == NULL) {
77 				search_msg(sp, S_NOPREV);
78 				return (1);
79 			}
80 			/* Re-compile the search pattern if necessary. */
81 			if (!F_ISSET(sp, SC_RE_SEARCH) && re_compile(sp,
82 			    sp->re, sp->re_len, NULL, NULL, &sp->re_c,
83 			    RE_C_SEARCH |
84 			    (LF_ISSET(SEARCH_MSG) ? 0 : RE_C_SILENT)))
85 				return (1);
86 
87 			/* Set the search direction. */
88 			if (LF_ISSET(SEARCH_SET))
89 				sp->searchdir = dir;
90 			return (0);
91 		}
92 
93 		/*
94 		 * Set the delimiter, and move forward to the terminating
95 		 * delimiter, handling escaped delimiters.
96 		 *
97 		 * QUOTING NOTE:
98 		 * Only discard an escape character if it escapes a delimiter.
99 		 */
100 		for (delim = *ptrn, p = t = ++ptrn;; *t++ = *p++) {
101 			if (--plen == 0 || p[0] == delim) {
102 				if (plen != 0)
103 					++p;
104 				break;
105 			}
106 			if (plen > 1 && p[0] == '\\' && p[1] == delim) {
107 				++p;
108 				--plen;
109 			}
110 		}
111 		if (epp != NULL)
112 			*epp = p;
113 
114 		plen = t - ptrn;
115 	}
116 
117 	/* Compile the RE. */
118 	if (re_compile(sp, ptrn, plen, &sp->re, &sp->re_len, &sp->re_c,
119 	    RE_C_SEARCH |
120 	    (LF_ISSET(SEARCH_MSG) ? 0 : RE_C_SILENT) |
121 	    (LF_ISSET(SEARCH_TAG) ? RE_C_TAG : 0) |
122 	    (LF_ISSET(SEARCH_CSCOPE) ? RE_C_CSCOPE : 0)))
123 		return (1);
124 
125 	/* Set the search direction. */
126 	if (LF_ISSET(SEARCH_SET))
127 		sp->searchdir = dir;
128 
129 	return (0);
130 }
131 
132 /*
133  * f_search --
134  *	Do a forward search.
135  *
136  * PUBLIC: int f_search(SCR *,
137  * PUBLIC:    MARK *, MARK *, CHAR_T *, size_t, CHAR_T **, u_int);
138  */
139 int
140 f_search(SCR *sp, MARK *fm, MARK *rm, CHAR_T *ptrn, size_t plen,
141     CHAR_T **eptrn, u_int flags)
142 {
143 	busy_t btype;
144 	recno_t lno;
145 	regmatch_t match[1];
146 	size_t coff, len;
147 	int cnt, eval, rval, wrapped = 0;
148 	CHAR_T *l;
149 
150 	if (search_init(sp, FORWARD, ptrn, plen, eptrn, flags))
151 		return (1);
152 
153 	if (LF_ISSET(SEARCH_FILE)) {
154 		lno = 1;
155 		coff = 0;
156 	} else {
157 		if (db_get(sp, fm->lno, DBG_FATAL, &l, &len))
158 			return (1);
159 		lno = fm->lno;
160 
161 		/*
162 		 * If doing incremental search, start searching at the previous
163 		 * column, so that we search a minimal distance and still match
164 		 * special patterns, e.g., \< for beginning of a word.
165 		 *
166 		 * Otherwise, start searching immediately after the cursor.  If
167 		 * at the end of the line, start searching on the next line.
168 		 * This is incompatible (read bug fix) with the historic vi --
169 		 * searches for the '$' pattern never moved forward, and the
170 		 * "-t foo" didn't work if the 'f' was the first character in
171 		 * the file.
172 		 */
173 		if (LF_ISSET(SEARCH_INCR)) {
174 			if ((coff = fm->cno) != 0)
175 				--coff;
176 		} else if (fm->cno + 1 >= len) {
177 			coff = 0;
178 			lno = fm->lno + 1;
179 			if (db_get(sp, lno, 0, &l, &len)) {
180 				if (!O_ISSET(sp, O_WRAPSCAN)) {
181 					if (LF_ISSET(SEARCH_MSG))
182 						search_msg(sp, S_EOF);
183 					return (1);
184 				}
185 				lno = 1;
186 				wrapped = 1;
187 			}
188 		} else
189 			coff = fm->cno + 1;
190 	}
191 
192 	btype = BUSY_ON;
193 	for (cnt = INTERRUPT_CHECK, rval = 1;; ++lno, coff = 0) {
194 		if (cnt-- == 0) {
195 			if (INTERRUPTED(sp))
196 				break;
197 			if (LF_ISSET(SEARCH_MSG)) {
198 				search_busy(sp, btype);
199 				btype = BUSY_UPDATE;
200 			}
201 			cnt = INTERRUPT_CHECK;
202 		}
203 		if ((wrapped && lno > fm->lno) || db_get(sp, lno, 0, &l, &len)) {
204 			if (wrapped) {
205 				if (LF_ISSET(SEARCH_MSG))
206 					search_msg(sp, S_NOTFOUND);
207 				break;
208 			}
209 			if (!O_ISSET(sp, O_WRAPSCAN)) {
210 				if (LF_ISSET(SEARCH_MSG))
211 					search_msg(sp, S_EOF);
212 				break;
213 			}
214 			lno = 0;
215 			wrapped = 1;
216 			continue;
217 		}
218 
219 		/* If already at EOL, just keep going. */
220 		if (len != 0 && coff == len)
221 			continue;
222 
223 		/* Set the termination. */
224 		match[0].rm_so = coff;
225 		match[0].rm_eo = len;
226 
227 #if defined(DEBUG) && 0
228 		TRACE(sp, "F search: %lu from %u to %u\n",
229 		    lno, coff, len != 0 ? len - 1 : len);
230 #endif
231 		/* Search the line. */
232 		eval = regexec(&sp->re_c, l, 1, match,
233 		    (match[0].rm_so == 0 ? 0 : REG_NOTBOL) | REG_STARTEND);
234 		if (eval == REG_NOMATCH)
235 			continue;
236 		if (eval != 0) {
237 			if (LF_ISSET(SEARCH_MSG))
238 				re_error(sp, eval, &sp->re_c);
239 			else
240 				(void)sp->gp->scr_bell(sp);
241 			break;
242 		}
243 
244 		/* Warn if the search wrapped. */
245 		if (wrapped && LF_ISSET(SEARCH_WMSG))
246 			search_msg(sp, S_WRAP);
247 
248 #if defined(DEBUG) && 0
249 		TRACE(sp, "F search: %qu to %qu\n",
250 		    match[0].rm_so, match[0].rm_eo);
251 #endif
252 		rm->lno = lno;
253 		rm->cno = match[0].rm_so;
254 
255 		/*
256 		 * If a change command, it's possible to move beyond the end
257 		 * of a line.  Historic vi generally got this wrong (e.g. try
258 		 * "c?$<cr>").  Not all that sure this gets it right, there
259 		 * are lots of strange cases.
260 		 */
261 		if (!LF_ISSET(SEARCH_EOL) && rm->cno >= len)
262 			rm->cno = len != 0 ? len - 1 : 0;
263 
264 		rval = 0;
265 		break;
266 	}
267 
268 	if (LF_ISSET(SEARCH_MSG))
269 		search_busy(sp, BUSY_OFF);
270 	return (rval);
271 }
272 
273 /*
274  * b_search --
275  *	Do a backward search.
276  *
277  * PUBLIC: int b_search(SCR *,
278  * PUBLIC:    MARK *, MARK *, CHAR_T *, size_t, CHAR_T **, u_int);
279  */
280 int
281 b_search(SCR *sp, MARK *fm, MARK *rm, CHAR_T *ptrn, size_t plen,
282     CHAR_T **eptrn, u_int flags)
283 {
284 	busy_t btype;
285 	recno_t lno;
286 	regmatch_t match[1];
287 	size_t coff, last, len;
288 	int cnt, eval, rval, wrapped;
289 	CHAR_T *l;
290 
291 	if (search_init(sp, BACKWARD, ptrn, plen, eptrn, flags))
292 		return (1);
293 
294 	/*
295 	 * If doing incremental search, set the "starting" position past the
296 	 * current column, so that we search a minimal distance and still
297 	 * match special patterns, e.g., \> for the end of a word.  This is
298 	 * safe when the cursor is at the end of a line because we only use
299 	 * it for comparison with the location of the match.
300 	 *
301 	 * Otherwise, start searching immediately before the cursor.  If in
302 	 * the first column, start search on the previous line.
303 	 */
304 	if (LF_ISSET(SEARCH_INCR)) {
305 		lno = fm->lno;
306 		coff = fm->cno + 1;
307 	} else {
308 		if (fm->cno == 0) {
309 			if (fm->lno == 1 && !O_ISSET(sp, O_WRAPSCAN)) {
310 				if (LF_ISSET(SEARCH_MSG))
311 					search_msg(sp, S_SOF);
312 				return (1);
313 			}
314 			lno = fm->lno - 1;
315 		} else
316 			lno = fm->lno;
317 		coff = fm->cno;
318 	}
319 
320 	btype = BUSY_ON;
321 	for (cnt = INTERRUPT_CHECK, rval = 1, wrapped = 0;; --lno, coff = 0) {
322 		if (cnt-- == 0) {
323 			if (INTERRUPTED(sp))
324 				break;
325 			if (LF_ISSET(SEARCH_MSG)) {
326 				search_busy(sp, btype);
327 				btype = BUSY_UPDATE;
328 			}
329 			cnt = INTERRUPT_CHECK;
330 		}
331 		if ((wrapped && lno < fm->lno) || lno == 0) {
332 			if (wrapped) {
333 				if (LF_ISSET(SEARCH_MSG))
334 					search_msg(sp, S_NOTFOUND);
335 				break;
336 			}
337 			if (!O_ISSET(sp, O_WRAPSCAN)) {
338 				if (LF_ISSET(SEARCH_MSG))
339 					search_msg(sp, S_SOF);
340 				break;
341 			}
342 			if (db_last(sp, &lno))
343 				break;
344 			if (lno == 0) {
345 				if (LF_ISSET(SEARCH_MSG))
346 					search_msg(sp, S_EMPTY);
347 				break;
348 			}
349 			++lno;
350 			wrapped = 1;
351 			continue;
352 		}
353 
354 		if (db_get(sp, lno, 0, &l, &len))
355 			break;
356 
357 		/* Set the termination. */
358 		match[0].rm_so = 0;
359 		match[0].rm_eo = len;
360 
361 #if defined(DEBUG) && 0
362 		TRACE(sp, "B search: %lu from 0 to %qu\n", lno, match[0].rm_eo);
363 #endif
364 		/* Search the line. */
365 		eval = regexec(&sp->re_c, l, 1, match,
366 		    (match[0].rm_eo == len ? 0 : REG_NOTEOL) | REG_STARTEND);
367 		if (eval == REG_NOMATCH)
368 			continue;
369 		if (eval != 0) {
370 			if (LF_ISSET(SEARCH_MSG))
371 				re_error(sp, eval, &sp->re_c);
372 			else
373 				(void)sp->gp->scr_bell(sp);
374 			break;
375 		}
376 
377 		/* Check for a match starting past the cursor. */
378 		if (coff != 0 && match[0].rm_so >= coff)
379 			continue;
380 
381 		/* Warn if the search wrapped. */
382 		if (wrapped && LF_ISSET(SEARCH_WMSG))
383 			search_msg(sp, S_WRAP);
384 
385 #if defined(DEBUG) && 0
386 		TRACE(sp, "B found: %qu to %qu\n",
387 		    match[0].rm_so, match[0].rm_eo);
388 #endif
389 		/*
390 		 * We now have the first match on the line.  Step through the
391 		 * line character by character until find the last acceptable
392 		 * match.  This is painful, we need a better interface to regex
393 		 * to make this work.
394 		 */
395 		for (;;) {
396 			last = match[0].rm_so++;
397 			if (match[0].rm_so >= len)
398 				break;
399 			match[0].rm_eo = len;
400 			eval = regexec(&sp->re_c, l, 1, match,
401 			    (match[0].rm_so == 0 ? 0 : REG_NOTBOL) |
402 			    REG_STARTEND);
403 			if (eval == REG_NOMATCH)
404 				break;
405 			if (eval != 0) {
406 				if (LF_ISSET(SEARCH_MSG))
407 					re_error(sp, eval, &sp->re_c);
408 				else
409 					(void)sp->gp->scr_bell(sp);
410 				goto err;
411 			}
412 			if (coff && match[0].rm_so >= coff)
413 				break;
414 		}
415 		rm->lno = lno;
416 
417 		/* See comment in f_search(). */
418 		if (!LF_ISSET(SEARCH_EOL) && last >= len)
419 			rm->cno = len != 0 ? len - 1 : 0;
420 		else
421 			rm->cno = last;
422 		rval = 0;
423 		break;
424 	}
425 
426 err:	if (LF_ISSET(SEARCH_MSG))
427 		search_busy(sp, BUSY_OFF);
428 	return (rval);
429 }
430 
431 /*
432  * search_msg --
433  *	Display one of the search messages.
434  */
435 static void
436 search_msg(SCR *sp, smsg_t msg)
437 {
438 	switch (msg) {
439 	case S_EMPTY:
440 		msgq(sp, M_ERR, "072|File empty; nothing to search");
441 		break;
442 	case S_EOF:
443 		msgq(sp, M_ERR,
444 		    "073|Reached end-of-file without finding the pattern");
445 		break;
446 	case S_NOPREV:
447 		msgq(sp, M_ERR, "074|No previous search pattern");
448 		break;
449 	case S_NOTFOUND:
450 		msgq(sp, M_ERR, "075|Pattern not found");
451 		break;
452 	case S_SOF:
453 		msgq(sp, M_ERR,
454 		    "076|Reached top-of-file without finding the pattern");
455 		break;
456 	case S_WRAP:
457 		msgq(sp, M_ERR, "077|Search wrapped");
458 		break;
459 	default:
460 		abort();
461 	}
462 }
463 
464 /*
465  * search_busy --
466  *	Put up the busy searching message.
467  *
468  * PUBLIC: void search_busy(SCR *, busy_t);
469  */
470 void
471 search_busy(SCR *sp, busy_t btype)
472 {
473 	sp->gp->scr_busy(sp, "078|Searching...", btype);
474 }
475