xref: /freebsd/usr.bin/grep/util.c (revision aa24f48b361effe51163877d84f1b70d32b77e04)
1 /*	$NetBSD: util.c,v 1.9 2011/02/27 17:33:37 joerg Exp $	*/
2 /*	$FreeBSD$	*/
3 /*	$OpenBSD: util.c,v 1.39 2010/07/02 22:18:03 tedu Exp $	*/
4 
5 /*-
6  * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
7  * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org>
8  * Copyright (C) 2017 Kyle Evans <kevans@FreeBSD.org>
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/stat.h>
37 #include <sys/types.h>
38 
39 #include <ctype.h>
40 #include <err.h>
41 #include <errno.h>
42 #include <fnmatch.h>
43 #include <fts.h>
44 #include <libgen.h>
45 #include <stdbool.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <wchar.h>
51 #include <wctype.h>
52 
53 #ifndef WITHOUT_FASTMATCH
54 #include "fastmatch.h"
55 #endif
56 #include "grep.h"
57 
58 static bool	 first_match = true;
59 
60 /*
61  * Parsing context; used to hold things like matches made and
62  * other useful bits
63  */
64 struct parsec {
65 	regmatch_t	matches[MAX_MATCHES];		/* Matches made */
66 	struct str	ln;				/* Current line */
67 	size_t		lnstart;			/* Position in line */
68 	size_t		matchidx;			/* Latest match index */
69 	int		printed;			/* Metadata printed? */
70 	bool		binary;				/* Binary file? */
71 };
72 
73 
74 static int procline(struct parsec *pc);
75 static void printline(struct parsec *pc, int sep);
76 static void printline_metadata(struct str *line, int sep);
77 
78 bool
79 file_matching(const char *fname)
80 {
81 	char *fname_base, *fname_buf;
82 	bool ret;
83 
84 	ret = finclude ? false : true;
85 	fname_buf = strdup(fname);
86 	if (fname_buf == NULL)
87 		err(2, "strdup");
88 	fname_base = basename(fname_buf);
89 
90 	for (unsigned int i = 0; i < fpatterns; ++i) {
91 		if (fnmatch(fpattern[i].pat, fname, 0) == 0 ||
92 		    fnmatch(fpattern[i].pat, fname_base, 0) == 0) {
93 			if (fpattern[i].mode == EXCL_PAT) {
94 				ret = false;
95 				break;
96 			} else
97 				ret = true;
98 		}
99 	}
100 	free(fname_buf);
101 	return (ret);
102 }
103 
104 static inline bool
105 dir_matching(const char *dname)
106 {
107 	bool ret;
108 
109 	ret = dinclude ? false : true;
110 
111 	for (unsigned int i = 0; i < dpatterns; ++i) {
112 		if (dname != NULL &&
113 		    fnmatch(dpattern[i].pat, dname, 0) == 0) {
114 			if (dpattern[i].mode == EXCL_PAT)
115 				return (false);
116 			else
117 				ret = true;
118 		}
119 	}
120 	return (ret);
121 }
122 
123 /*
124  * Processes a directory when a recursive search is performed with
125  * the -R option.  Each appropriate file is passed to procfile().
126  */
127 int
128 grep_tree(char **argv)
129 {
130 	FTS *fts;
131 	FTSENT *p;
132 	int c, fts_flags;
133 	bool ok;
134 	const char *wd[] = { ".", NULL };
135 
136 	c = fts_flags = 0;
137 
138 	switch(linkbehave) {
139 	case LINK_EXPLICIT:
140 		fts_flags = FTS_COMFOLLOW;
141 		break;
142 	case LINK_SKIP:
143 		fts_flags = FTS_PHYSICAL;
144 		break;
145 	default:
146 		fts_flags = FTS_LOGICAL;
147 
148 	}
149 
150 	fts_flags |= FTS_NOSTAT | FTS_NOCHDIR;
151 
152 	fts = fts_open((argv[0] == NULL) ?
153 	    __DECONST(char * const *, wd) : argv, fts_flags, NULL);
154 	if (fts == NULL)
155 		err(2, "fts_open");
156 	while ((p = fts_read(fts)) != NULL) {
157 		switch (p->fts_info) {
158 		case FTS_DNR:
159 			/* FALLTHROUGH */
160 		case FTS_ERR:
161 			file_err = true;
162 			if(!sflag)
163 				warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
164 			break;
165 		case FTS_D:
166 			/* FALLTHROUGH */
167 		case FTS_DP:
168 			if (dexclude || dinclude)
169 				if (!dir_matching(p->fts_name) ||
170 				    !dir_matching(p->fts_path))
171 					fts_set(fts, p, FTS_SKIP);
172 			break;
173 		case FTS_DC:
174 			/* Print a warning for recursive directory loop */
175 			warnx("warning: %s: recursive directory loop",
176 				p->fts_path);
177 			break;
178 		default:
179 			/* Check for file exclusion/inclusion */
180 			ok = true;
181 			if (fexclude || finclude)
182 				ok &= file_matching(p->fts_path);
183 
184 			if (ok)
185 				c += procfile(p->fts_path);
186 			break;
187 		}
188 	}
189 
190 	fts_close(fts);
191 	return (c);
192 }
193 
194 /*
195  * Opens a file and processes it.  Each file is processed line-by-line
196  * passing the lines to procline().
197  */
198 int
199 procfile(const char *fn)
200 {
201 	struct parsec pc;
202 	long long tail;
203 	struct file *f;
204 	struct stat sb;
205 	struct str *ln;
206 	mode_t s;
207 	int c, last_outed, t;
208 	bool doctx, printmatch, same_file;
209 
210 	if (strcmp(fn, "-") == 0) {
211 		fn = label != NULL ? label : getstr(1);
212 		f = grep_open(NULL);
213 	} else {
214 		if (!stat(fn, &sb)) {
215 			/* Check if we need to process the file */
216 			s = sb.st_mode & S_IFMT;
217 			if (s == S_IFDIR && dirbehave == DIR_SKIP)
218 				return (0);
219 			if ((s == S_IFIFO || s == S_IFCHR || s == S_IFBLK
220 				|| s == S_IFSOCK) && devbehave == DEV_SKIP)
221 					return (0);
222 		}
223 		f = grep_open(fn);
224 	}
225 	if (f == NULL) {
226 		file_err = true;
227 		if (!sflag)
228 			warn("%s", fn);
229 		return (0);
230 	}
231 
232 	/* Convenience */
233 	ln = &pc.ln;
234 	pc.ln.file = grep_malloc(strlen(fn) + 1);
235 	strcpy(pc.ln.file, fn);
236 	pc.ln.line_no = 0;
237 	pc.ln.len = 0;
238 	pc.ln.boff = 0;
239 	pc.ln.off = -1;
240 	pc.binary = f->binary;
241 	pc.printed = 0;
242 	tail = 0;
243 	last_outed = 0;
244 	same_file = false;
245 	doctx = false;
246 	printmatch = true;
247 	if ((pc.binary && binbehave == BINFILE_BIN) || cflag || qflag ||
248 	    lflag || Lflag)
249 		printmatch = false;
250 	if (printmatch && (Aflag != 0 || Bflag != 0))
251 		doctx = true;
252 	mcount = mlimit;
253 
254 	for (c = 0;  c == 0 || !(lflag || qflag); ) {
255 		/* Reset per-line statistics */
256 		pc.printed = 0;
257 		pc.matchidx = 0;
258 		pc.lnstart = 0;
259 		pc.ln.boff = 0;
260 		pc.ln.off += pc.ln.len + 1;
261 		if ((pc.ln.dat = grep_fgetln(f, &pc.ln.len)) == NULL ||
262 		    pc.ln.len == 0) {
263 			if (pc.ln.line_no == 0 && matchall)
264 				/*
265 				 * An empty file with an empty pattern and the
266 				 * -w flag does not match
267 				 */
268 				exit(matchall && wflag ? 1 : 0);
269 			else
270 				break;
271 		}
272 
273 		if (pc.ln.len > 0 && pc.ln.dat[pc.ln.len - 1] == fileeol)
274 			--pc.ln.len;
275 		pc.ln.line_no++;
276 
277 		/* Return if we need to skip a binary file */
278 		if (pc.binary && binbehave == BINFILE_SKIP) {
279 			grep_close(f);
280 			free(pc.ln.file);
281 			free(f);
282 			return (0);
283 		}
284 
285 		if ((t = procline(&pc)) == 0)
286 			++c;
287 
288 		/* Deal with any -B context or context separators */
289 		if (t == 0 && doctx) {
290 			if (!first_match && (!same_file || last_outed > 0))
291 				printf("--\n");
292 			if (Bflag > 0)
293 				printqueue();
294 			tail = Aflag;
295 		}
296 		/* Print the matching line, but only if not quiet/binary */
297 		if (t == 0 && printmatch) {
298 			printline(&pc, ':');
299 			while (pc.matchidx >= MAX_MATCHES) {
300 				/* Reset matchidx and try again */
301 				pc.matchidx = 0;
302 				if (procline(&pc) == 0)
303 					printline(&pc, ':');
304 				else
305 					break;
306 			}
307 			first_match = false;
308 			same_file = true;
309 			last_outed = 0;
310 		}
311 		if (t != 0 && doctx) {
312 			/* Deal with any -A context */
313 			if (tail > 0) {
314 				grep_printline(&pc.ln, '-');
315 				tail--;
316 				if (Bflag > 0)
317 					clearqueue();
318 			} else {
319 				/*
320 				 * Enqueue non-matching lines for -B context.
321 				 * If we're not actually doing -B context or if
322 				 * the enqueue resulted in a line being rotated
323 				 * out, then go ahead and increment last_outed
324 				 * to signify a gap between context/match.
325 				 */
326 				if (Bflag == 0 || (Bflag > 0 && enqueue(ln)))
327 					++last_outed;
328 			}
329 		}
330 
331 		/* Count the matches if we have a match limit */
332 		if (t == 0 && mflag) {
333 			--mcount;
334 			if (mflag && mcount <= 0)
335 				break;
336 		}
337 
338 	}
339 	if (Bflag > 0)
340 		clearqueue();
341 	grep_close(f);
342 
343 	if (cflag) {
344 		if (!hflag)
345 			printf("%s:", pc.ln.file);
346 		printf("%u\n", c);
347 	}
348 	if (lflag && !qflag && c != 0)
349 		printf("%s%c", fn, nullflag ? 0 : '\n');
350 	if (Lflag && !qflag && c == 0)
351 		printf("%s%c", fn, nullflag ? 0 : '\n');
352 	if (c && !cflag && !lflag && !Lflag &&
353 	    binbehave == BINFILE_BIN && f->binary && !qflag)
354 		printf(getstr(8), fn);
355 
356 	free(pc.ln.file);
357 	free(f);
358 	return (c);
359 }
360 
361 #define iswword(x)	(iswalnum((x)) || (x) == L'_')
362 
363 /*
364  * Processes a line comparing it with the specified patterns.  Each pattern
365  * is looped to be compared along with the full string, saving each and every
366  * match, which is necessary to colorize the output and to count the
367  * matches.  The matching lines are passed to printline() to display the
368  * appropriate output.
369  */
370 static int
371 procline(struct parsec *pc)
372 {
373 	regmatch_t pmatch, lastmatch, chkmatch;
374 	wchar_t wbegin, wend;
375 	size_t st, nst;
376 	unsigned int i;
377 	int c = 0, r = 0, lastmatches = 0, leflags = eflags;
378 	size_t startm = 0, matchidx;
379 	unsigned int retry;
380 
381 	matchidx = pc->matchidx;
382 
383 	/* Special case: empty pattern with -w flag, check first character */
384 	if (matchall && wflag) {
385 		if (pc->ln.len == 0)
386 			return (0);
387 		wend = L' ';
388 		if (sscanf(&pc->ln.dat[0], "%lc", &wend) != 1 || iswword(wend))
389 			return (1);
390 		else
391 			return (0);
392 	} else if (matchall)
393 		return (0);
394 
395 	st = pc->lnstart;
396 	nst = 0;
397 	/* Initialize to avoid a false positive warning from GCC. */
398 	lastmatch.rm_so = lastmatch.rm_eo = 0;
399 
400 	/* Loop to process the whole line */
401 	while (st <= pc->ln.len) {
402 		lastmatches = 0;
403 		startm = matchidx;
404 		retry = 0;
405 		if (st > 0 && pc->ln.dat[st - 1] != fileeol)
406 			leflags |= REG_NOTBOL;
407 		/* Loop to compare with all the patterns */
408 		for (i = 0; i < patterns; i++) {
409 			pmatch.rm_so = st;
410 			pmatch.rm_eo = pc->ln.len;
411 #ifndef WITHOUT_FASTMATCH
412 			if (fg_pattern[i].pattern)
413 				r = fastexec(&fg_pattern[i],
414 				    pc->ln.dat, 1, &pmatch, leflags);
415 			else
416 #endif
417 				r = regexec(&r_pattern[i], pc->ln.dat, 1,
418 				    &pmatch, leflags);
419 			if (r != 0)
420 				continue;
421 			/* Check for full match */
422 			if (xflag && (pmatch.rm_so != 0 ||
423 			    (size_t)pmatch.rm_eo != pc->ln.len))
424 				continue;
425 			/* Check for whole word match */
426 #ifndef WITHOUT_FASTMATCH
427 			if (wflag || fg_pattern[i].word) {
428 #else
429 			if (wflag) {
430 #endif
431 				wbegin = wend = L' ';
432 				if (pmatch.rm_so != 0 &&
433 				    sscanf(&pc->ln.dat[pmatch.rm_so - 1],
434 				    "%lc", &wbegin) != 1)
435 					r = REG_NOMATCH;
436 				else if ((size_t)pmatch.rm_eo !=
437 				    pc->ln.len &&
438 				    sscanf(&pc->ln.dat[pmatch.rm_eo],
439 				    "%lc", &wend) != 1)
440 					r = REG_NOMATCH;
441 				else if (iswword(wbegin) ||
442 				    iswword(wend))
443 					r = REG_NOMATCH;
444 				/*
445 				 * If we're doing whole word matching and we
446 				 * matched once, then we should try the pattern
447 				 * again after advancing just past the start of
448 				 * the earliest match. This allows the pattern
449 				 * to  match later on in the line and possibly
450 				 * still match a whole word.
451 				 */
452 				if (r == REG_NOMATCH &&
453 				    (retry == pc->lnstart ||
454 				    pmatch.rm_so + 1 < retry))
455 					retry = pmatch.rm_so + 1;
456 				if (r == REG_NOMATCH)
457 					continue;
458 			}
459 			lastmatches++;
460 			lastmatch = pmatch;
461 
462 			if (matchidx == 0)
463 				c++;
464 
465 			/*
466 			 * Replace previous match if the new one is earlier
467 			 * and/or longer. This will lead to some amount of
468 			 * extra work if -o/--color are specified, but it's
469 			 * worth it from a correctness point of view.
470 			 */
471 			if (matchidx > startm) {
472 				chkmatch = pc->matches[matchidx - 1];
473 				if (pmatch.rm_so < chkmatch.rm_so ||
474 				    (pmatch.rm_so == chkmatch.rm_so &&
475 				    (pmatch.rm_eo - pmatch.rm_so) >
476 				    (chkmatch.rm_eo - chkmatch.rm_so))) {
477 					pc->matches[matchidx - 1] = pmatch;
478 					nst = pmatch.rm_eo;
479 				}
480 			} else {
481 				/* Advance as normal if not */
482 				pc->matches[matchidx++] = pmatch;
483 				nst = pmatch.rm_eo;
484 			}
485 			/* avoid excessive matching - skip further patterns */
486 			if ((color == NULL && !oflag) || qflag || lflag ||
487 			    matchidx >= MAX_MATCHES) {
488 				pc->lnstart = nst;
489 				lastmatches = 0;
490 				break;
491 			}
492 		}
493 
494 		/*
495 		 * Advance to just past the start of the earliest match, try
496 		 * again just in case we still have a chance to match later in
497 		 * the string.
498 		 */
499 		if (lastmatches == 0 && retry > pc->lnstart) {
500 			st = retry;
501 			continue;
502 		}
503 
504 		/* One pass if we are not recording matches */
505 		if (!wflag && ((color == NULL && !oflag) || qflag || lflag || Lflag))
506 			break;
507 
508 		/* If we didn't have any matches or REG_NOSUB set */
509 		if (lastmatches == 0 || (cflags & REG_NOSUB))
510 			nst = pc->ln.len;
511 
512 		if (lastmatches == 0)
513 			/* No matches */
514 			break;
515 		else if (st == nst && lastmatch.rm_so == lastmatch.rm_eo)
516 			/* Zero-length match -- advance one more so we don't get stuck */
517 			nst++;
518 
519 		/* Advance st based on previous matches */
520 		st = nst;
521 		pc->lnstart = st;
522 	}
523 
524 	/* Reflect the new matchidx in the context */
525 	pc->matchidx = matchidx;
526 	if (vflag)
527 		c = !c;
528 	return (c ? 0 : 1);
529 }
530 
531 /*
532  * Safe malloc() for internal use.
533  */
534 void *
535 grep_malloc(size_t size)
536 {
537 	void *ptr;
538 
539 	if ((ptr = malloc(size)) == NULL)
540 		err(2, "malloc");
541 	return (ptr);
542 }
543 
544 /*
545  * Safe calloc() for internal use.
546  */
547 void *
548 grep_calloc(size_t nmemb, size_t size)
549 {
550 	void *ptr;
551 
552 	if ((ptr = calloc(nmemb, size)) == NULL)
553 		err(2, "calloc");
554 	return (ptr);
555 }
556 
557 /*
558  * Safe realloc() for internal use.
559  */
560 void *
561 grep_realloc(void *ptr, size_t size)
562 {
563 
564 	if ((ptr = realloc(ptr, size)) == NULL)
565 		err(2, "realloc");
566 	return (ptr);
567 }
568 
569 /*
570  * Safe strdup() for internal use.
571  */
572 char *
573 grep_strdup(const char *str)
574 {
575 	char *ret;
576 
577 	if ((ret = strdup(str)) == NULL)
578 		err(2, "strdup");
579 	return (ret);
580 }
581 
582 /*
583  * Print an entire line as-is, there are no inline matches to consider. This is
584  * used for printing context.
585  */
586 void grep_printline(struct str *line, int sep) {
587 	printline_metadata(line, sep);
588 	fwrite(line->dat, line->len, 1, stdout);
589 	putchar(fileeol);
590 }
591 
592 static void
593 printline_metadata(struct str *line, int sep)
594 {
595 	bool printsep;
596 
597 	printsep = false;
598 	if (!hflag) {
599 		if (!nullflag) {
600 			fputs(line->file, stdout);
601 			printsep = true;
602 		} else {
603 			printf("%s", line->file);
604 			putchar(0);
605 		}
606 	}
607 	if (nflag) {
608 		if (printsep)
609 			putchar(sep);
610 		printf("%d", line->line_no);
611 		printsep = true;
612 	}
613 	if (bflag) {
614 		if (printsep)
615 			putchar(sep);
616 		printf("%lld", (long long)(line->off + line->boff));
617 		printsep = true;
618 	}
619 	if (printsep)
620 		putchar(sep);
621 }
622 
623 /*
624  * Prints a matching line according to the command line options.
625  */
626 static void
627 printline(struct parsec *pc, int sep)
628 {
629 	size_t a = 0;
630 	size_t i, matchidx;
631 	regmatch_t match;
632 
633 	/* If matchall, everything matches but don't actually print for -o */
634 	if (oflag && matchall)
635 		return;
636 
637 	matchidx = pc->matchidx;
638 
639 	/* --color and -o */
640 	if ((oflag || color) && matchidx > 0) {
641 		/* Only print metadata once per line if --color */
642 		if (!oflag && pc->printed == 0)
643 			printline_metadata(&pc->ln, sep);
644 		for (i = 0; i < matchidx; i++) {
645 			match = pc->matches[i];
646 			/* Don't output zero length matches */
647 			if (match.rm_so == match.rm_eo)
648 				continue;
649 			/*
650 			 * Metadata is printed on a per-line basis, so every
651 			 * match gets file metadata with the -o flag.
652 			 */
653 			if (oflag) {
654 				pc->ln.boff = match.rm_so;
655 				printline_metadata(&pc->ln, sep);
656 			} else
657 				fwrite(pc->ln.dat + a, match.rm_so - a, 1,
658 				    stdout);
659 			if (color)
660 				fprintf(stdout, "\33[%sm\33[K", color);
661 			fwrite(pc->ln.dat + match.rm_so,
662 			    match.rm_eo - match.rm_so, 1, stdout);
663 			if (color)
664 				fprintf(stdout, "\33[m\33[K");
665 			a = match.rm_eo;
666 			if (oflag)
667 				putchar('\n');
668 		}
669 		if (!oflag) {
670 			if (pc->ln.len - a > 0)
671 				fwrite(pc->ln.dat + a, pc->ln.len - a, 1,
672 				    stdout);
673 			putchar('\n');
674 		}
675 	} else
676 		grep_printline(&pc->ln, sep);
677 	pc->printed++;
678 }
679