xref: /openbsd-src/usr.bin/grep/util.c (revision 9f11ffb7133c203312a01e4b986886bc88c7d74b) 
1 /*	$OpenBSD: util.c,v 1.59 2019/01/23 23:00:54 tedu Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 James Howard and Dag-Erling Co�dan Sm�rgrav
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 
32 #include <ctype.h>
33 #include <err.h>
34 #include <errno.h>
35 #include <fts.h>
36 #include <regex.h>
37 #include <stdbool.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 #include <zlib.h>
43 
44 #include "grep.h"
45 
46 /*
47  * Process a file line by line...
48  */
49 
50 static int	linesqueued;
51 static int	procline(str_t *l, int);
52 static int	grep_search(fastgrep_t *, char *, size_t, regmatch_t *pmatch, int);
53 #ifndef SMALL
54 static bool	grep_cmp(const char *, const char *, size_t);
55 static void	grep_revstr(unsigned char *, int);
56 #endif
57 
58 int
59 grep_tree(char **argv)
60 {
61 	FTS	*fts;
62 	FTSENT	*p;
63 	int	c, fts_flags;
64 
65 	c = 0;
66 
67 	fts_flags = FTS_PHYSICAL | FTS_NOSTAT | FTS_NOCHDIR;
68 
69 	if (!(fts = fts_open(argv, fts_flags, NULL)))
70 		err(2, NULL);
71 	while ((p = fts_read(fts)) != NULL) {
72 		switch (p->fts_info) {
73 		case FTS_DNR:
74 			break;
75 		case FTS_ERR:
76 			file_err = 1;
77 			if(!sflag)
78 				warnc(p->fts_errno, "%s", p->fts_path);
79 			break;
80 		case FTS_D:
81 		case FTS_DP:
82 			break;
83 		default:
84 			c += procfile(p->fts_path);
85 			break;
86 		}
87 	}
88 	if (errno)
89 		err(2, "fts_read");
90 	fts_close(fts);
91 	return c;
92 }
93 
94 int
95 procfile(char *fn)
96 {
97 	str_t ln;
98 	file_t *f;
99 	int c, t, z, nottext;
100 
101 	mcount = mlimit;
102 
103 	if (fn == NULL) {
104 		fn = "(standard input)";
105 		f = grep_fdopen(STDIN_FILENO);
106 	} else {
107 		f = grep_open(fn);
108 	}
109 	if (f == NULL) {
110 		if (errno == EISDIR)
111 			return 0;
112 		file_err = 1;
113 		if (!sflag)
114 			warn("%s", fn);
115 		return 0;
116 	}
117 
118 	nottext = grep_bin_file(f);
119 	if (nottext && binbehave == BIN_FILE_SKIP) {
120 		grep_close(f);
121 		return 0;
122 	}
123 
124 	ln.file = fn;
125 	ln.line_no = 0;
126 	ln.len = 0;
127 	linesqueued = 0;
128 	tail = 0;
129 	ln.off = -1;
130 
131 	if (Bflag > 0)
132 		initqueue();
133 	for (c = 0;  c == 0 || !(lflag || qflag); ) {
134 		if (mflag && mlimit == 0)
135 			break;
136 		ln.off += ln.len + 1;
137 		if ((ln.dat = grep_fgetln(f, &ln.len)) == NULL)
138 			break;
139 		if (ln.len > 0 && ln.dat[ln.len - 1] == '\n')
140 			--ln.len;
141 		ln.line_no++;
142 
143 		z = tail;
144 
145 		if ((t = procline(&ln, nottext)) == 0 && Bflag > 0 && z == 0) {
146 			enqueue(&ln);
147 			linesqueued++;
148 		}
149 		c += t;
150 		if (mflag && mcount <= 0)
151 			break;
152 	}
153 	if (Bflag > 0)
154 		clearqueue();
155 	grep_close(f);
156 
157 	if (cflag) {
158 		if (!hflag)
159 			printf("%s:", ln.file);
160 		printf("%u\n", c);
161 	}
162 	if (lflag && c != 0)
163 		printf("%s\n", fn);
164 	if (Lflag && c == 0)
165 		printf("%s\n", fn);
166 	if (c && !cflag && !lflag && !Lflag &&
167 	    binbehave == BIN_FILE_BIN && nottext && !qflag)
168 		printf("Binary file %s matches\n", fn);
169 
170 	return c;
171 }
172 
173 
174 /*
175  * Process an individual line in a file. Return non-zero if it matches.
176  */
177 
178 #define isword(x) (isalnum((unsigned char)x) || (x) == '_')
179 
180 static int
181 procline(str_t *l, int nottext)
182 {
183 	regmatch_t	pmatch = { 0 };
184 	int		c, i, r;
185 	regoff_t	offset;
186 
187 	/* size_t will be converted to regoff_t. ssize_t is guaranteed to fit
188 	 * into regoff_t */
189 	if (l->len > SSIZE_MAX) {
190 		errx(2, "Line is too big to process");
191 	}
192 
193 	c = 0;
194 	i = 0;
195 	if (matchall) {
196 		c = 1;
197 		goto print;
198 	}
199 
200 	for (i = 0; i < patterns; i++) {
201 		offset = 0;
202 redo:
203 		if (fg_pattern[i].pattern) {
204 			int flags = 0;
205 			if (offset)
206 				flags |= REG_NOTBOL;
207 			r = grep_search(&fg_pattern[i], l->dat + offset,
208 			    l->len - offset, &pmatch, flags);
209 			pmatch.rm_so += offset;
210 			pmatch.rm_eo += offset;
211 		} else {
212 			int flags = eflags;
213 			if (offset)
214 				flags |= REG_NOTBOL;
215 			pmatch.rm_so = offset;
216 			pmatch.rm_eo = l->len;
217 			r = regexec(&r_pattern[i], l->dat, 1, &pmatch, flags);
218 		}
219 		if (r == 0 && xflag) {
220 			if (pmatch.rm_so != 0 || pmatch.rm_eo != l->len)
221 				r = REG_NOMATCH;
222 		}
223 		if (r == 0) {
224 			c = 1;
225 			if (oflag && pmatch.rm_so != pmatch.rm_eo)
226 				goto print;
227 			break;
228 		}
229 	}
230 	if (oflag)
231 		return c;
232 print:
233 	if (vflag)
234 		c = !c;
235 
236 	/* Count the matches if we have a match limit */
237 	if (mflag)
238 		mcount -= c;
239 
240 	if (c && binbehave == BIN_FILE_BIN && nottext)
241 		return c; /* Binary file */
242 
243 	if ((tail > 0 || c) && !cflag && !qflag) {
244 		if (c) {
245 			if (first > 0 && tail == 0 && (Bflag < linesqueued) &&
246 			    (Aflag || Bflag))
247 				printf("--\n");
248 			first = 1;
249 			tail = Aflag;
250 			if (Bflag > 0)
251 				printqueue();
252 			linesqueued = 0;
253 			printline(l, ':', oflag ? &pmatch : NULL);
254 		} else {
255 			printline(l, '-', oflag ? &pmatch : NULL);
256 			tail--;
257 		}
258 	}
259 	if (oflag && !matchall) {
260 		offset = pmatch.rm_eo;
261 		goto redo;
262 	}
263 	return c;
264 }
265 
266 #ifndef SMALL
267 void
268 fgrepcomp(fastgrep_t *fg, const unsigned char *pattern)
269 {
270 	int i;
271 
272 	/* Initialize. */
273 	fg->patternLen = strlen(pattern);
274 	fg->bol = 0;
275 	fg->eol = 0;
276 	fg->wmatch = wflag;
277 	fg->reversedSearch = 0;
278 
279 	/*
280 	 * Make a copy and upper case it for later if in -i mode,
281 	 * else just copy the pointer.
282 	 */
283 	if (iflag) {
284 		fg->pattern = grep_malloc(fg->patternLen + 1);
285 		for (i = 0; i < fg->patternLen; i++)
286 			fg->pattern[i] = toupper(pattern[i]);
287 		fg->pattern[fg->patternLen] = '\0';
288 	} else
289 		fg->pattern = (unsigned char *)pattern;	/* really const */
290 
291 	/* Preprocess pattern. */
292 	for (i = 0; i <= UCHAR_MAX; i++)
293 		fg->qsBc[i] = fg->patternLen;
294 	for (i = 1; i < fg->patternLen; i++) {
295 		fg->qsBc[fg->pattern[i]] = fg->patternLen - i;
296 		/*
297 		 * If case is ignored, make the jump apply to both upper and
298 		 * lower cased characters.  As the pattern is stored in upper
299 		 * case, apply the same to the lower case equivalents.
300 		 */
301 		if (iflag)
302 			fg->qsBc[tolower(fg->pattern[i])] = fg->patternLen - i;
303 	}
304 }
305 #endif
306 
307 /*
308  * Returns: -1 on failure, 0 on success
309  */
310 int
311 fastcomp(fastgrep_t *fg, const char *pattern)
312 {
313 #ifdef SMALL
314 	return -1;
315 #else
316 	int i;
317 	int bol = 0;
318 	int eol = 0;
319 	int shiftPatternLen;
320 	int hasDot = 0;
321 	int firstHalfDot = -1;
322 	int firstLastHalfDot = -1;
323 	int lastHalfDot = 0;
324 
325 	/* Initialize. */
326 	fg->patternLen = strlen(pattern);
327 	fg->bol = 0;
328 	fg->eol = 0;
329 	fg->wmatch = 0;
330 	fg->reversedSearch = 0;
331 
332 	/* Remove end-of-line character ('$'). */
333 	if (fg->patternLen > 0 && pattern[fg->patternLen - 1] == '$') {
334 		eol++;
335 		fg->eol = 1;
336 		fg->patternLen--;
337 	}
338 
339 	/* Remove beginning-of-line character ('^'). */
340 	if (pattern[0] == '^') {
341 		bol++;
342 		fg->bol = 1;
343 		fg->patternLen--;
344 	}
345 
346 	/* Remove enclosing [[:<:]] and [[:>:]] (word match). */
347 	if (wflag) {
348 		/* basic re's use \( \), extended re's ( ) */
349 		int extra = Eflag ? 1 : 2;
350 		fg->patternLen -= 14 + 2 * extra;
351 		fg->wmatch = 7 + extra;
352 	} else if (fg->patternLen >= 14 &&
353 	    strncmp(pattern + fg->bol, "[[:<:]]", 7) == 0 &&
354 	    strncmp(pattern + fg->bol + fg->patternLen - 7, "[[:>:]]", 7) == 0) {
355 		fg->patternLen -= 14;
356 		fg->wmatch = 7;
357 	}
358 
359 	/*
360 	 * Copy pattern minus '^' and '$' characters as well as word
361 	 * match character classes at the beginning and ending of the
362 	 * string respectively.
363 	 */
364 	fg->pattern = grep_malloc(fg->patternLen + 1);
365 	memcpy(fg->pattern, pattern + bol + fg->wmatch, fg->patternLen);
366 	fg->pattern[fg->patternLen] = '\0';
367 
368 	/* Look for ways to cheat...er...avoid the full regex engine. */
369 	for (i = 0; i < fg->patternLen; i++)
370 	{
371 		switch (fg->pattern[i]) {
372 		case '.':
373 			hasDot = i;
374 			if (i < fg->patternLen / 2) {
375 				if (firstHalfDot < 0)
376 					/* Closest dot to the beginning */
377 					firstHalfDot = i;
378 			} else {
379 				/* Closest dot to the end of the pattern. */
380 				lastHalfDot = i;
381 				if (firstLastHalfDot < 0)
382 					firstLastHalfDot = i;
383 			}
384 			break;
385 		case '(': case ')':
386 		case '{': case '}':
387 			/* Special in BRE if preceded by '\\' */
388 		case '?':
389 		case '+':
390 		case '|':
391 			/* Not special in BRE. */
392 			if (!Eflag)
393 				goto nonspecial;
394 		case '\\':
395 		case '*':
396 		case '[': case ']':
397 			/* Free memory and let others know this is empty. */
398 			free(fg->pattern);
399 			fg->pattern = NULL;
400 			return (-1);
401 		default:
402 nonspecial:
403 			if (iflag)
404 				fg->pattern[i] = toupper(fg->pattern[i]);
405 			break;
406 		}
407 	}
408 
409 	/*
410 	 * Determine if a reverse search would be faster based on the placement
411 	 * of the dots.
412 	 */
413 	if ((!(lflag || cflag || oflag)) && ((!(bol || eol)) &&
414 	    ((lastHalfDot) && ((firstHalfDot < 0) ||
415 	    ((fg->patternLen - (lastHalfDot + 1)) < firstHalfDot))))) {
416 		fg->reversedSearch = 1;
417 		hasDot = fg->patternLen - (firstHalfDot < 0 ?
418 		    firstLastHalfDot : firstHalfDot) - 1;
419 		grep_revstr(fg->pattern, fg->patternLen);
420 	}
421 
422 	/*
423 	 * Normal Quick Search would require a shift based on the position the
424 	 * next character after the comparison is within the pattern.  With
425 	 * wildcards, the position of the last dot effects the maximum shift
426 	 * distance.
427 	 * The closer to the end the wild card is the slower the search.  A
428 	 * reverse version of this algorithm would be useful for wildcards near
429 	 * the end of the string.
430 	 *
431 	 * Examples:
432 	 * Pattern	Max shift
433 	 * -------	---------
434 	 * this		5
435 	 * .his		4
436 	 * t.is		3
437 	 * th.s		2
438 	 * thi.		1
439 	 */
440 
441 	/* Adjust the shift based on location of the last dot ('.'). */
442 	shiftPatternLen = fg->patternLen - hasDot;
443 
444 	/* Preprocess pattern. */
445 	for (i = 0; i <= UCHAR_MAX; i++)
446 		fg->qsBc[i] = shiftPatternLen;
447 	for (i = hasDot + 1; i < fg->patternLen; i++) {
448 		fg->qsBc[fg->pattern[i]] = fg->patternLen - i;
449 		/*
450 		 * If case is ignored, make the jump apply to both upper and
451 		 * lower cased characters.  As the pattern is stored in upper
452 		 * case, apply the same to the lower case equivalents.
453 		 */
454 		if (iflag)
455 			fg->qsBc[tolower(fg->pattern[i])] = fg->patternLen - i;
456 	}
457 
458 	/*
459 	 * Put pattern back to normal after pre-processing to allow for easy
460 	 * comparisons later.
461 	 */
462 	if (fg->reversedSearch)
463 		grep_revstr(fg->pattern, fg->patternLen);
464 
465 	return (0);
466 #endif
467 }
468 
469 /*
470  * Word boundaries using regular expressions are defined as the point
471  * of transition from a non-word char to a word char, or vice versa.
472  * This means that grep -w +a and grep -w a+ never match anything,
473  * because they lack a starting or ending transition, but grep -w a+b
474  * does match a line containing a+b.
475  */
476 #define wmatch(d, l, s, e)	\
477 	((s == 0 || !isword(d[s-1])) && (e == l || !isword(d[e])) && \
478 	  e > s && isword(d[s]) && isword(d[e-1]))
479 
480 static int
481 grep_search(fastgrep_t *fg, char *data, size_t dataLen, regmatch_t *pmatch,
482     int flags)
483 {
484 #ifdef SMALL
485 	return 0;
486 #else
487 	regoff_t j;
488 	int rtrnVal = REG_NOMATCH;
489 
490 	pmatch->rm_so = -1;
491 	pmatch->rm_eo = -1;
492 
493 	/* No point in going farther if we do not have enough data. */
494 	if (dataLen < fg->patternLen)
495 		return (rtrnVal);
496 
497 	/* Only try once at the beginning or ending of the line. */
498 	if (fg->bol || fg->eol) {
499 		if (fg->bol && (flags & REG_NOTBOL))
500 			return 0;
501 		/* Simple text comparison. */
502 		/* Verify data is >= pattern length before searching on it. */
503 		if (dataLen >= fg->patternLen) {
504 			/* Determine where in data to start search at. */
505 			if (fg->eol)
506 				j = dataLen - fg->patternLen;
507 			else
508 				j = 0;
509 			if (!((fg->bol && fg->eol) && (dataLen != fg->patternLen)))
510 				if (grep_cmp(fg->pattern, data + j,
511 				    fg->patternLen)) {
512 					pmatch->rm_so = j;
513 					pmatch->rm_eo = j + fg->patternLen;
514 					if (!fg->wmatch || wmatch(data, dataLen,
515 					    pmatch->rm_so, pmatch->rm_eo))
516 						rtrnVal = 0;
517 				}
518 		}
519 	} else if (fg->reversedSearch) {
520 		/* Quick Search algorithm. */
521 		j = dataLen;
522 		do {
523 			if (grep_cmp(fg->pattern, data + j - fg->patternLen,
524 			    fg->patternLen)) {
525 				pmatch->rm_so = j - fg->patternLen;
526 				pmatch->rm_eo = j;
527 				if (!fg->wmatch || wmatch(data, dataLen,
528 				    pmatch->rm_so, pmatch->rm_eo)) {
529 					rtrnVal = 0;
530 					break;
531 				}
532 			}
533 			/* Shift if within bounds, otherwise, we are done. */
534 			if (j == fg->patternLen)
535 				break;
536 			j -= fg->qsBc[(unsigned char)data[j - fg->patternLen - 1]];
537 		} while (j >= fg->patternLen);
538 	} else {
539 		/* Quick Search algorithm. */
540 		j = 0;
541 		do {
542 			if (grep_cmp(fg->pattern, data + j, fg->patternLen)) {
543 				pmatch->rm_so = j;
544 				pmatch->rm_eo = j + fg->patternLen;
545 				if (fg->patternLen == 0 || !fg->wmatch ||
546 				    wmatch(data, dataLen, pmatch->rm_so,
547 				    pmatch->rm_eo)) {
548 					rtrnVal = 0;
549 					break;
550 				}
551 			}
552 
553 			/* Shift if within bounds, otherwise, we are done. */
554 			if (j + fg->patternLen == dataLen)
555 				break;
556 			else
557 				j += fg->qsBc[(unsigned char)data[j + fg->patternLen]];
558 		} while (j <= (dataLen - fg->patternLen));
559 	}
560 
561 	return (rtrnVal);
562 #endif
563 }
564 
565 
566 void *
567 grep_malloc(size_t size)
568 {
569 	void	*ptr;
570 
571 	if ((ptr = malloc(size)) == NULL)
572 		err(2, "malloc");
573 	return ptr;
574 }
575 
576 void *
577 grep_calloc(size_t nmemb, size_t size)
578 {
579 	void	*ptr;
580 
581 	if ((ptr = calloc(nmemb, size)) == NULL)
582 		err(2, "calloc");
583 	return ptr;
584 }
585 
586 void *
587 grep_realloc(void *ptr, size_t size)
588 {
589 	if ((ptr = realloc(ptr, size)) == NULL)
590 		err(2, "realloc");
591 	return ptr;
592 }
593 
594 void *
595 grep_reallocarray(void *ptr, size_t nmemb, size_t size)
596 {
597 	if ((ptr = reallocarray(ptr, nmemb, size)) == NULL)
598 		err(2, "reallocarray");
599 	return ptr;
600 }
601 
602 #ifndef SMALL
603 /*
604  * Returns:	true on success, false on failure
605  */
606 static bool
607 grep_cmp(const char *pattern, const char *data, size_t len)
608 {
609 	size_t i;
610 
611 	for (i = 0; i < len; i++) {
612 		if (((pattern[i] == data[i]) || (!Fflag && pattern[i] == '.'))
613 		    || (iflag && pattern[i] == toupper((unsigned char)data[i])))
614 			continue;
615 		return false;
616 	}
617 
618 	return true;
619 }
620 
621 static void
622 grep_revstr(unsigned char *str, int len)
623 {
624 	int i;
625 	char c;
626 
627 	for (i = 0; i < len / 2; i++) {
628 		c = str[i];
629 		str[i] = str[len - i - 1];
630 		str[len - i - 1] = c;
631 	}
632 }
633 #endif
634 
635 void
636 printline(str_t *line, int sep, regmatch_t *pmatch)
637 {
638 	int n;
639 
640 	n = 0;
641 	if (!hflag) {
642 		fputs(line->file, stdout);
643 		++n;
644 	}
645 	if (nflag) {
646 		if (n)
647 			putchar(sep);
648 		printf("%lld", line->line_no);
649 		++n;
650 	}
651 	if (bflag) {
652 		if (n)
653 			putchar(sep);
654 		printf("%lld", (long long)line->off);
655 		++n;
656 	}
657 	if (n)
658 		putchar(sep);
659 	if (pmatch)
660 		fwrite(line->dat + pmatch->rm_so,
661 		    pmatch->rm_eo - pmatch->rm_so, 1, stdout);
662 	else
663 		fwrite(line->dat, line->len, 1, stdout);
664 	putchar('\n');
665 }
666