xref: /freebsd/usr.bin/grep/util.c (revision 56e53cb8ef000c3ef72337a4095987a932cdedef)
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  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
7  *
8  * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
9  * Copyright (C) 2008-2010 Gabor Kovesdan <gabor@FreeBSD.org>
10  * Copyright (C) 2017 Kyle Evans <kevans@FreeBSD.org>
11  * All rights reserved.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/stat.h>
39 #include <sys/types.h>
40 
41 #include <ctype.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <fnmatch.h>
45 #include <fts.h>
46 #include <libgen.h>
47 #include <stdbool.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <wchar.h>
53 #include <wctype.h>
54 
55 #ifndef WITHOUT_FASTMATCH
56 #include "fastmatch.h"
57 #endif
58 #include "grep.h"
59 
60 static bool	 first_match = true;
61 
62 /*
63  * Parsing context; used to hold things like matches made and
64  * other useful bits
65  */
66 struct parsec {
67 	regmatch_t	matches[MAX_MATCHES];		/* Matches made */
68 	struct str	ln;				/* Current line */
69 	size_t		lnstart;			/* Position in line */
70 	size_t		matchidx;			/* Latest match index */
71 	int		printed;			/* Metadata printed? */
72 	bool		binary;				/* Binary file? */
73 };
74 
75 #ifdef WITH_INTERNAL_NOSPEC
76 static int litexec(const struct pat *pat, const char *string,
77     size_t nmatch, regmatch_t pmatch[]);
78 #endif
79 static int procline(struct parsec *pc);
80 static void printline(struct parsec *pc, int sep);
81 static void printline_metadata(struct str *line, int sep);
82 
83 bool
84 file_matching(const char *fname)
85 {
86 	char *fname_base, *fname_buf;
87 	bool ret;
88 
89 	ret = finclude ? false : true;
90 	fname_buf = strdup(fname);
91 	if (fname_buf == NULL)
92 		err(2, "strdup");
93 	fname_base = basename(fname_buf);
94 
95 	for (unsigned int i = 0; i < fpatterns; ++i) {
96 		if (fnmatch(fpattern[i].pat, fname, 0) == 0 ||
97 		    fnmatch(fpattern[i].pat, fname_base, 0) == 0) {
98 			if (fpattern[i].mode == EXCL_PAT) {
99 				ret = false;
100 				break;
101 			} else
102 				ret = true;
103 		}
104 	}
105 	free(fname_buf);
106 	return (ret);
107 }
108 
109 static inline bool
110 dir_matching(const char *dname)
111 {
112 	bool ret;
113 
114 	ret = dinclude ? false : true;
115 
116 	for (unsigned int i = 0; i < dpatterns; ++i) {
117 		if (dname != NULL &&
118 		    fnmatch(dpattern[i].pat, dname, 0) == 0) {
119 			if (dpattern[i].mode == EXCL_PAT)
120 				return (false);
121 			else
122 				ret = true;
123 		}
124 	}
125 	return (ret);
126 }
127 
128 /*
129  * Processes a directory when a recursive search is performed with
130  * the -R option.  Each appropriate file is passed to procfile().
131  */
132 int
133 grep_tree(char **argv)
134 {
135 	FTS *fts;
136 	FTSENT *p;
137 	int c, fts_flags;
138 	bool ok;
139 	const char *wd[] = { ".", NULL };
140 
141 	c = fts_flags = 0;
142 
143 	switch(linkbehave) {
144 	case LINK_EXPLICIT:
145 		fts_flags = FTS_COMFOLLOW;
146 		break;
147 	case LINK_SKIP:
148 		fts_flags = FTS_PHYSICAL;
149 		break;
150 	default:
151 		fts_flags = FTS_LOGICAL;
152 
153 	}
154 
155 	fts_flags |= FTS_NOSTAT | FTS_NOCHDIR;
156 
157 	fts = fts_open((argv[0] == NULL) ?
158 	    __DECONST(char * const *, wd) : argv, fts_flags, NULL);
159 	if (fts == NULL)
160 		err(2, "fts_open");
161 	while ((p = fts_read(fts)) != NULL) {
162 		switch (p->fts_info) {
163 		case FTS_DNR:
164 			/* FALLTHROUGH */
165 		case FTS_ERR:
166 			file_err = true;
167 			if(!sflag)
168 				warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
169 			break;
170 		case FTS_D:
171 			/* FALLTHROUGH */
172 		case FTS_DP:
173 			if (dexclude || dinclude)
174 				if (!dir_matching(p->fts_name) ||
175 				    !dir_matching(p->fts_path))
176 					fts_set(fts, p, FTS_SKIP);
177 			break;
178 		case FTS_DC:
179 			/* Print a warning for recursive directory loop */
180 			warnx("warning: %s: recursive directory loop",
181 				p->fts_path);
182 			break;
183 		default:
184 			/* Check for file exclusion/inclusion */
185 			ok = true;
186 			if (fexclude || finclude)
187 				ok &= file_matching(p->fts_path);
188 
189 			if (ok)
190 				c += procfile(p->fts_path);
191 			break;
192 		}
193 	}
194 
195 	fts_close(fts);
196 	return (c);
197 }
198 
199 /*
200  * Opens a file and processes it.  Each file is processed line-by-line
201  * passing the lines to procline().
202  */
203 int
204 procfile(const char *fn)
205 {
206 	struct parsec pc;
207 	long long tail;
208 	struct file *f;
209 	struct stat sb;
210 	struct str *ln;
211 	mode_t s;
212 	int c, last_outed, t;
213 	bool doctx, printmatch, same_file;
214 
215 	if (strcmp(fn, "-") == 0) {
216 		fn = label != NULL ? label : getstr(1);
217 		f = grep_open(NULL);
218 	} else {
219 		if (!stat(fn, &sb)) {
220 			/* Check if we need to process the file */
221 			s = sb.st_mode & S_IFMT;
222 			if (s == S_IFDIR && dirbehave == DIR_SKIP)
223 				return (0);
224 			if ((s == S_IFIFO || s == S_IFCHR || s == S_IFBLK
225 				|| s == S_IFSOCK) && devbehave == DEV_SKIP)
226 					return (0);
227 		}
228 		f = grep_open(fn);
229 	}
230 	if (f == NULL) {
231 		file_err = true;
232 		if (!sflag)
233 			warn("%s", fn);
234 		return (0);
235 	}
236 
237 	/* Convenience */
238 	ln = &pc.ln;
239 	pc.ln.file = grep_malloc(strlen(fn) + 1);
240 	strcpy(pc.ln.file, fn);
241 	pc.ln.line_no = 0;
242 	pc.ln.len = 0;
243 	pc.ln.boff = 0;
244 	pc.ln.off = -1;
245 	pc.binary = f->binary;
246 	pc.printed = 0;
247 	tail = 0;
248 	last_outed = 0;
249 	same_file = false;
250 	doctx = false;
251 	printmatch = true;
252 	if ((pc.binary && binbehave == BINFILE_BIN) || cflag || qflag ||
253 	    lflag || Lflag)
254 		printmatch = false;
255 	if (printmatch && (Aflag != 0 || Bflag != 0))
256 		doctx = true;
257 	mcount = mlimit;
258 
259 	for (c = 0;  c == 0 || !(lflag || qflag); ) {
260 		/* Reset per-line statistics */
261 		pc.printed = 0;
262 		pc.matchidx = 0;
263 		pc.lnstart = 0;
264 		pc.ln.boff = 0;
265 		pc.ln.off += pc.ln.len + 1;
266 		if ((pc.ln.dat = grep_fgetln(f, &pc.ln.len)) == NULL ||
267 		    pc.ln.len == 0)
268 			break;
269 
270 		if (pc.ln.len > 0 && pc.ln.dat[pc.ln.len - 1] == fileeol)
271 			--pc.ln.len;
272 		pc.ln.line_no++;
273 
274 		/* Return if we need to skip a binary file */
275 		if (pc.binary && binbehave == BINFILE_SKIP) {
276 			grep_close(f);
277 			free(pc.ln.file);
278 			free(f);
279 			return (0);
280 		}
281 
282 		if ((t = procline(&pc)) == 0)
283 			++c;
284 
285 		/* Deal with any -B context or context separators */
286 		if (t == 0 && doctx) {
287 			if (!first_match && (!same_file || last_outed > 0))
288 				printf("--\n");
289 			if (Bflag > 0)
290 				printqueue();
291 			tail = Aflag;
292 		}
293 		/* Print the matching line, but only if not quiet/binary */
294 		if (t == 0 && printmatch) {
295 			printline(&pc, ':');
296 			while (pc.matchidx >= MAX_MATCHES) {
297 				/* Reset matchidx and try again */
298 				pc.matchidx = 0;
299 				if (procline(&pc) == 0)
300 					printline(&pc, ':');
301 				else
302 					break;
303 			}
304 			first_match = false;
305 			same_file = true;
306 			last_outed = 0;
307 		}
308 		if (t != 0 && doctx) {
309 			/* Deal with any -A context */
310 			if (tail > 0) {
311 				grep_printline(&pc.ln, '-');
312 				tail--;
313 				if (Bflag > 0)
314 					clearqueue();
315 			} else {
316 				/*
317 				 * Enqueue non-matching lines for -B context.
318 				 * If we're not actually doing -B context or if
319 				 * the enqueue resulted in a line being rotated
320 				 * out, then go ahead and increment last_outed
321 				 * to signify a gap between context/match.
322 				 */
323 				if (Bflag == 0 || (Bflag > 0 && enqueue(ln)))
324 					++last_outed;
325 			}
326 		}
327 
328 		/* Count the matches if we have a match limit */
329 		if (t == 0 && mflag) {
330 			--mcount;
331 			if (mflag && mcount <= 0)
332 				break;
333 		}
334 
335 	}
336 	if (Bflag > 0)
337 		clearqueue();
338 	grep_close(f);
339 
340 	if (cflag) {
341 		if (!hflag)
342 			printf("%s:", pc.ln.file);
343 		printf("%u\n", c);
344 	}
345 	if (lflag && !qflag && c != 0)
346 		printf("%s%c", fn, nullflag ? 0 : '\n');
347 	if (Lflag && !qflag && c == 0)
348 		printf("%s%c", fn, nullflag ? 0 : '\n');
349 	if (c && !cflag && !lflag && !Lflag &&
350 	    binbehave == BINFILE_BIN && f->binary && !qflag)
351 		printf(getstr(8), fn);
352 
353 	free(pc.ln.file);
354 	free(f);
355 	return (c);
356 }
357 
358 #ifdef WITH_INTERNAL_NOSPEC
359 /*
360  * Internal implementation of literal string search within a string, modeled
361  * after regexec(3), for use when the regex(3) implementation doesn't offer
362  * either REG_NOSPEC or REG_LITERAL. This does not apply in the default FreeBSD
363  * config, but in other scenarios such as building against libgnuregex or on
364  * some non-FreeBSD OSes.
365  */
366 static int
367 litexec(const struct pat *pat, const char *string, size_t nmatch,
368     regmatch_t pmatch[])
369 {
370 	char *(*strstr_fn)(const char *, const char *);
371 	char *sub, *subject;
372 	const char *search;
373 	size_t idx, n, ofs, stringlen;
374 
375 	if (cflags & REG_ICASE)
376 		strstr_fn = strcasestr;
377 	else
378 		strstr_fn = strstr;
379 	idx = 0;
380 	ofs = pmatch[0].rm_so;
381 	stringlen = pmatch[0].rm_eo;
382 	if (ofs >= stringlen)
383 		return (REG_NOMATCH);
384 	subject = strndup(string, stringlen);
385 	if (subject == NULL)
386 		return (REG_ESPACE);
387 	for (n = 0; ofs < stringlen;) {
388 		search = (subject + ofs);
389 		if ((unsigned long)pat->len > strlen(search))
390 			break;
391 		sub = strstr_fn(search, pat->pat);
392 		/*
393 		 * Ignoring the empty string possibility due to context: grep optimizes
394 		 * for empty patterns and will never reach this point.
395 		 */
396 		if (sub == NULL)
397 			break;
398 		++n;
399 		/* Fill in pmatch if necessary */
400 		if (nmatch > 0) {
401 			pmatch[idx].rm_so = ofs + (sub - search);
402 			pmatch[idx].rm_eo = pmatch[idx].rm_so + pat->len;
403 			if (++idx == nmatch)
404 				break;
405 			ofs = pmatch[idx].rm_so + 1;
406 		} else
407 			/* We only needed to know if we match or not */
408 			break;
409 	}
410 	free(subject);
411 	if (n > 0 && nmatch > 0)
412 		for (n = idx; n < nmatch; ++n)
413 			pmatch[n].rm_so = pmatch[n].rm_eo = -1;
414 
415 	return (n > 0 ? 0 : REG_NOMATCH);
416 }
417 #endif /* WITH_INTERNAL_NOSPEC */
418 
419 #define iswword(x)	(iswalnum((x)) || (x) == L'_')
420 
421 /*
422  * Processes a line comparing it with the specified patterns.  Each pattern
423  * is looped to be compared along with the full string, saving each and every
424  * match, which is necessary to colorize the output and to count the
425  * matches.  The matching lines are passed to printline() to display the
426  * appropriate output.
427  */
428 static int
429 procline(struct parsec *pc)
430 {
431 	regmatch_t pmatch, lastmatch, chkmatch;
432 	wchar_t wbegin, wend;
433 	size_t st, nst;
434 	unsigned int i;
435 	int c = 0, r = 0, lastmatches = 0, leflags = eflags;
436 	size_t startm = 0, matchidx;
437 	unsigned int retry;
438 
439 	matchidx = pc->matchidx;
440 
441 	/* Special case: empty pattern with -w flag, check first character */
442 	if (matchall && wflag) {
443 		if (pc->ln.len == 0)
444 			return (0);
445 		wend = L' ';
446 		if (sscanf(&pc->ln.dat[0], "%lc", &wend) != 1 || iswword(wend))
447 			return (1);
448 		else
449 			return (0);
450 	} else if (matchall)
451 		return (0);
452 
453 	st = pc->lnstart;
454 	nst = 0;
455 	/* Initialize to avoid a false positive warning from GCC. */
456 	lastmatch.rm_so = lastmatch.rm_eo = 0;
457 
458 	/* Loop to process the whole line */
459 	while (st <= pc->ln.len) {
460 		lastmatches = 0;
461 		startm = matchidx;
462 		retry = 0;
463 		if (st > 0 && pc->ln.dat[st - 1] != fileeol)
464 			leflags |= REG_NOTBOL;
465 		/* Loop to compare with all the patterns */
466 		for (i = 0; i < patterns; i++) {
467 			pmatch.rm_so = st;
468 			pmatch.rm_eo = pc->ln.len;
469 #ifdef WITH_INTERNAL_NOSPEC
470 			if (grepbehave == GREP_FIXED)
471 				r = litexec(&pattern[i], pc->ln.dat, 1, &pmatch);
472 			else
473 #endif
474 #ifndef WITHOUT_FASTMATCH
475 			if (fg_pattern[i].pattern)
476 				r = fastexec(&fg_pattern[i],
477 				    pc->ln.dat, 1, &pmatch, leflags);
478 			else
479 #endif
480 				r = regexec(&r_pattern[i], pc->ln.dat, 1,
481 				    &pmatch, leflags);
482 			if (r != 0)
483 				continue;
484 			/* Check for full match */
485 			if (xflag && (pmatch.rm_so != 0 ||
486 			    (size_t)pmatch.rm_eo != pc->ln.len))
487 				continue;
488 			/* Check for whole word match */
489 #ifndef WITHOUT_FASTMATCH
490 			if (wflag || fg_pattern[i].word) {
491 #else
492 			if (wflag) {
493 #endif
494 				wbegin = wend = L' ';
495 				if (pmatch.rm_so != 0 &&
496 				    sscanf(&pc->ln.dat[pmatch.rm_so - 1],
497 				    "%lc", &wbegin) != 1)
498 					r = REG_NOMATCH;
499 				else if ((size_t)pmatch.rm_eo !=
500 				    pc->ln.len &&
501 				    sscanf(&pc->ln.dat[pmatch.rm_eo],
502 				    "%lc", &wend) != 1)
503 					r = REG_NOMATCH;
504 				else if (iswword(wbegin) ||
505 				    iswword(wend))
506 					r = REG_NOMATCH;
507 				/*
508 				 * If we're doing whole word matching and we
509 				 * matched once, then we should try the pattern
510 				 * again after advancing just past the start of
511 				 * the earliest match. This allows the pattern
512 				 * to  match later on in the line and possibly
513 				 * still match a whole word.
514 				 */
515 				if (r == REG_NOMATCH &&
516 				    (retry == pc->lnstart ||
517 				    (unsigned int)pmatch.rm_so + 1 < retry))
518 					retry = pmatch.rm_so + 1;
519 				if (r == REG_NOMATCH)
520 					continue;
521 			}
522 			lastmatches++;
523 			lastmatch = pmatch;
524 
525 			if (matchidx == 0)
526 				c++;
527 
528 			/*
529 			 * Replace previous match if the new one is earlier
530 			 * and/or longer. This will lead to some amount of
531 			 * extra work if -o/--color are specified, but it's
532 			 * worth it from a correctness point of view.
533 			 */
534 			if (matchidx > startm) {
535 				chkmatch = pc->matches[matchidx - 1];
536 				if (pmatch.rm_so < chkmatch.rm_so ||
537 				    (pmatch.rm_so == chkmatch.rm_so &&
538 				    (pmatch.rm_eo - pmatch.rm_so) >
539 				    (chkmatch.rm_eo - chkmatch.rm_so))) {
540 					pc->matches[matchidx - 1] = pmatch;
541 					nst = pmatch.rm_eo;
542 				}
543 			} else {
544 				/* Advance as normal if not */
545 				pc->matches[matchidx++] = pmatch;
546 				nst = pmatch.rm_eo;
547 			}
548 			/* avoid excessive matching - skip further patterns */
549 			if ((color == NULL && !oflag) || qflag || lflag ||
550 			    matchidx >= MAX_MATCHES) {
551 				pc->lnstart = nst;
552 				lastmatches = 0;
553 				break;
554 			}
555 		}
556 
557 		/*
558 		 * Advance to just past the start of the earliest match, try
559 		 * again just in case we still have a chance to match later in
560 		 * the string.
561 		 */
562 		if (lastmatches == 0 && retry > pc->lnstart) {
563 			st = retry;
564 			continue;
565 		}
566 
567 		/* One pass if we are not recording matches */
568 		if (!wflag && ((color == NULL && !oflag) || qflag || lflag || Lflag))
569 			break;
570 
571 		/* If we didn't have any matches or REG_NOSUB set */
572 		if (lastmatches == 0 || (cflags & REG_NOSUB))
573 			nst = pc->ln.len;
574 
575 		if (lastmatches == 0)
576 			/* No matches */
577 			break;
578 		else if (st == nst && lastmatch.rm_so == lastmatch.rm_eo)
579 			/* Zero-length match -- advance one more so we don't get stuck */
580 			nst++;
581 
582 		/* Advance st based on previous matches */
583 		st = nst;
584 		pc->lnstart = st;
585 	}
586 
587 	/* Reflect the new matchidx in the context */
588 	pc->matchidx = matchidx;
589 	if (vflag)
590 		c = !c;
591 	return (c ? 0 : 1);
592 }
593 
594 /*
595  * Safe malloc() for internal use.
596  */
597 void *
598 grep_malloc(size_t size)
599 {
600 	void *ptr;
601 
602 	if ((ptr = malloc(size)) == NULL)
603 		err(2, "malloc");
604 	return (ptr);
605 }
606 
607 /*
608  * Safe calloc() for internal use.
609  */
610 void *
611 grep_calloc(size_t nmemb, size_t size)
612 {
613 	void *ptr;
614 
615 	if ((ptr = calloc(nmemb, size)) == NULL)
616 		err(2, "calloc");
617 	return (ptr);
618 }
619 
620 /*
621  * Safe realloc() for internal use.
622  */
623 void *
624 grep_realloc(void *ptr, size_t size)
625 {
626 
627 	if ((ptr = realloc(ptr, size)) == NULL)
628 		err(2, "realloc");
629 	return (ptr);
630 }
631 
632 /*
633  * Safe strdup() for internal use.
634  */
635 char *
636 grep_strdup(const char *str)
637 {
638 	char *ret;
639 
640 	if ((ret = strdup(str)) == NULL)
641 		err(2, "strdup");
642 	return (ret);
643 }
644 
645 /*
646  * Print an entire line as-is, there are no inline matches to consider. This is
647  * used for printing context.
648  */
649 void grep_printline(struct str *line, int sep) {
650 	printline_metadata(line, sep);
651 	fwrite(line->dat, line->len, 1, stdout);
652 	putchar(fileeol);
653 }
654 
655 static void
656 printline_metadata(struct str *line, int sep)
657 {
658 	bool printsep;
659 
660 	printsep = false;
661 	if (!hflag) {
662 		if (!nullflag) {
663 			fputs(line->file, stdout);
664 			printsep = true;
665 		} else {
666 			printf("%s", line->file);
667 			putchar(0);
668 		}
669 	}
670 	if (nflag) {
671 		if (printsep)
672 			putchar(sep);
673 		printf("%d", line->line_no);
674 		printsep = true;
675 	}
676 	if (bflag) {
677 		if (printsep)
678 			putchar(sep);
679 		printf("%lld", (long long)(line->off + line->boff));
680 		printsep = true;
681 	}
682 	if (printsep)
683 		putchar(sep);
684 }
685 
686 /*
687  * Prints a matching line according to the command line options.
688  */
689 static void
690 printline(struct parsec *pc, int sep)
691 {
692 	size_t a = 0;
693 	size_t i, matchidx;
694 	regmatch_t match;
695 
696 	/* If matchall, everything matches but don't actually print for -o */
697 	if (oflag && matchall)
698 		return;
699 
700 	matchidx = pc->matchidx;
701 
702 	/* --color and -o */
703 	if ((oflag || color) && matchidx > 0) {
704 		/* Only print metadata once per line if --color */
705 		if (!oflag && pc->printed == 0)
706 			printline_metadata(&pc->ln, sep);
707 		for (i = 0; i < matchidx; i++) {
708 			match = pc->matches[i];
709 			/* Don't output zero length matches */
710 			if (match.rm_so == match.rm_eo)
711 				continue;
712 			/*
713 			 * Metadata is printed on a per-line basis, so every
714 			 * match gets file metadata with the -o flag.
715 			 */
716 			if (oflag) {
717 				pc->ln.boff = match.rm_so;
718 				printline_metadata(&pc->ln, sep);
719 			} else
720 				fwrite(pc->ln.dat + a, match.rm_so - a, 1,
721 				    stdout);
722 			if (color)
723 				fprintf(stdout, "\33[%sm\33[K", color);
724 			fwrite(pc->ln.dat + match.rm_so,
725 			    match.rm_eo - match.rm_so, 1, stdout);
726 			if (color)
727 				fprintf(stdout, "\33[m\33[K");
728 			a = match.rm_eo;
729 			if (oflag)
730 				putchar('\n');
731 		}
732 		if (!oflag) {
733 			if (pc->ln.len - a > 0)
734 				fwrite(pc->ln.dat + a, pc->ln.len - a, 1,
735 				    stdout);
736 			putchar('\n');
737 		}
738 	} else
739 		grep_printline(&pc->ln, sep);
740 	pc->printed++;
741 }
742