xref: /freebsd/usr.bin/grep/grep.c (revision fc12c191c087b63e1204fee210ba76082ea40b96)
1 /*	$NetBSD: grep.c,v 1.6 2011/04/18 03:48:23 joerg Exp $	*/
2 /*	$OpenBSD: grep.c,v 1.42 2010/07/02 22:18:03 tedu Exp $	*/
3 
4 /*-
5  * SPDX-License-Identifier: BSD-2-Clause
6  *
7  * Copyright (c) 1999 James Howard and Dag-Erling Smørgrav
8  * Copyright (C) 2008-2009 Gabor Kovesdan <gabor@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 #include <sys/stat.h>
35 #include <sys/types.h>
36 
37 #include <ctype.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <getopt.h>
42 #include <limits.h>
43 #include <libgen.h>
44 #include <locale.h>
45 #include <stdbool.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include "grep.h"
52 
53 const char	*errstr[] = {
54 	"",
55 /* 1*/	"(standard input)",
56 /* 2*/	"unknown %s option",
57 /* 3*/	"usage: %s [-abcDEFGHhIiLlmnOopqRSsUVvwxz] [-A num] [-B num] [-C num]\n",
58 /* 4*/	"\t[-e pattern] [-f file] [--binary-files=value] [--color=when]\n",
59 /* 5*/	"\t[--context=num] [--directories=action] [--label] [--line-buffered]\n",
60 /* 6*/	"\t[--null] [pattern] [file ...]\n",
61 /* 7*/	"Binary file %s matches\n",
62 /* 8*/	"%s (BSD grep, GNU compatible) %s\n",
63 };
64 
65 /* Flags passed to regcomp() and regexec() */
66 int		 cflags = REG_NOSUB | REG_NEWLINE;
67 int		 eflags = REG_STARTEND;
68 
69 bool		 matchall;
70 
71 /* Searching patterns */
72 unsigned int	 patterns;
73 static unsigned int pattern_sz;
74 struct pat	*pattern;
75 regex_t		*r_pattern;
76 
77 /* Filename exclusion/inclusion patterns */
78 unsigned int	fpatterns, dpatterns;
79 static unsigned int fpattern_sz, dpattern_sz;
80 struct epat	*dpattern, *fpattern;
81 
82 /* For regex errors  */
83 char	 re_error[RE_ERROR_BUF + 1];
84 
85 /* Command-line flags */
86 long long Aflag;	/* -A x: print x lines trailing each match */
87 long long Bflag;	/* -B x: print x lines leading each match */
88 bool	 Hflag;		/* -H: always print file name */
89 bool	 Lflag;		/* -L: only show names of files with no matches */
90 bool	 bflag;		/* -b: show block numbers for each match */
91 bool	 cflag;		/* -c: only show a count of matching lines */
92 bool	 hflag;		/* -h: don't print filename headers */
93 bool	 iflag;		/* -i: ignore case */
94 bool	 lflag;		/* -l: only show names of files with matches */
95 bool	 mflag;		/* -m x: stop reading the files after x matches */
96 long long mcount;	/* count for -m */
97 long long mlimit;	/* requested value for -m */
98 char	 fileeol;	/* indicator for eol */
99 bool	 nflag;		/* -n: show line numbers in front of matching lines */
100 bool	 oflag;		/* -o: print only matching part */
101 bool	 qflag;		/* -q: quiet mode (don't output anything) */
102 bool	 sflag;		/* -s: silent mode (ignore errors) */
103 bool	 vflag;		/* -v: only show non-matching lines */
104 bool	 wflag;		/* -w: pattern must start and end on word boundaries */
105 bool	 xflag;		/* -x: pattern must match entire line */
106 bool	 lbflag;	/* --line-buffered */
107 bool	 nullflag;	/* --null */
108 char	*label;		/* --label */
109 const char *color;	/* --color */
110 int	 grepbehave = GREP_BASIC;	/* -EFG: type of the regex */
111 int	 binbehave = BINFILE_BIN;	/* -aIU: handling of binary files */
112 int	 filebehave = FILE_STDIO;
113 int	 devbehave = DEV_READ;		/* -D: handling of devices */
114 int	 dirbehave = DIR_READ;		/* -dRr: handling of directories */
115 int	 linkbehave = LINK_SKIP;	/* -OpS: handling of symlinks */
116 
117 bool	 dexclude, dinclude;	/* --exclude-dir and --include-dir */
118 bool	 fexclude, finclude;	/* --exclude and --include */
119 
120 enum {
121 	BIN_OPT = CHAR_MAX + 1,
122 	COLOR_OPT,
123 	HELP_OPT,
124 	MMAP_OPT,
125 	LINEBUF_OPT,
126 	LABEL_OPT,
127 	NULL_OPT,
128 	R_EXCLUDE_OPT,
129 	R_INCLUDE_OPT,
130 	R_DEXCLUDE_OPT,
131 	R_DINCLUDE_OPT
132 };
133 
134 static inline const char	*init_color(const char *);
135 
136 /* Housekeeping */
137 bool	 file_err;	/* file reading error */
138 
139 /*
140  * Prints usage information and returns 2.
141  */
142 static void
usage(void)143 usage(void)
144 {
145 	fprintf(stderr, errstr[3], getprogname());
146 	fprintf(stderr, "%s", errstr[4]);
147 	fprintf(stderr, "%s", errstr[5]);
148 	fprintf(stderr, "%s", errstr[6]);
149 	exit(2);
150 }
151 
152 static const char	*optstr = "0123456789A:B:C:D:EFGHILOSRUVabcd:e:f:hilm:nopqrsuvwxyz";
153 
154 static const struct option long_options[] =
155 {
156 	{"binary-files",	required_argument,	NULL, BIN_OPT},
157 	{"help",		no_argument,		NULL, HELP_OPT},
158 	{"mmap",		no_argument,		NULL, MMAP_OPT},
159 	{"line-buffered",	no_argument,		NULL, LINEBUF_OPT},
160 	{"label",		required_argument,	NULL, LABEL_OPT},
161 	{"null",		no_argument,		NULL, NULL_OPT},
162 	{"color",		optional_argument,	NULL, COLOR_OPT},
163 	{"colour",		optional_argument,	NULL, COLOR_OPT},
164 	{"exclude",		required_argument,	NULL, R_EXCLUDE_OPT},
165 	{"include",		required_argument,	NULL, R_INCLUDE_OPT},
166 	{"exclude-dir",		required_argument,	NULL, R_DEXCLUDE_OPT},
167 	{"include-dir",		required_argument,	NULL, R_DINCLUDE_OPT},
168 	{"after-context",	required_argument,	NULL, 'A'},
169 	{"text",		no_argument,		NULL, 'a'},
170 	{"before-context",	required_argument,	NULL, 'B'},
171 	{"byte-offset",		no_argument,		NULL, 'b'},
172 	{"context",		optional_argument,	NULL, 'C'},
173 	{"count",		no_argument,		NULL, 'c'},
174 	{"devices",		required_argument,	NULL, 'D'},
175         {"directories",		required_argument,	NULL, 'd'},
176 	{"extended-regexp",	no_argument,		NULL, 'E'},
177 	{"regexp",		required_argument,	NULL, 'e'},
178 	{"fixed-strings",	no_argument,		NULL, 'F'},
179 	{"file",		required_argument,	NULL, 'f'},
180 	{"basic-regexp",	no_argument,		NULL, 'G'},
181 	{"no-filename",		no_argument,		NULL, 'h'},
182 	{"with-filename",	no_argument,		NULL, 'H'},
183 	{"ignore-case",		no_argument,		NULL, 'i'},
184 	{"files-with-matches",	no_argument,		NULL, 'l'},
185 	{"files-without-match", no_argument,            NULL, 'L'},
186 	{"max-count",		required_argument,	NULL, 'm'},
187 	{"line-number",		no_argument,		NULL, 'n'},
188 	{"only-matching",	no_argument,		NULL, 'o'},
189 	{"quiet",		no_argument,		NULL, 'q'},
190 	{"silent",		no_argument,		NULL, 'q'},
191 	{"recursive",		no_argument,		NULL, 'r'},
192 	{"no-messages",		no_argument,		NULL, 's'},
193 	{"binary",		no_argument,		NULL, 'U'},
194 	{"unix-byte-offsets",	no_argument,		NULL, 'u'},
195 	{"invert-match",	no_argument,		NULL, 'v'},
196 	{"version",		no_argument,		NULL, 'V'},
197 	{"word-regexp",		no_argument,		NULL, 'w'},
198 	{"line-regexp",		no_argument,		NULL, 'x'},
199 	{"null-data",		no_argument,		NULL, 'z'},
200 	{NULL,			no_argument,		NULL, 0}
201 };
202 
203 /*
204  * Adds a searching pattern to the internal array.
205  */
206 static void
add_pattern(char * pat,size_t len)207 add_pattern(char *pat, size_t len)
208 {
209 
210 	/* Check if we can do a shortcut */
211 	if (len == 0) {
212 		matchall = true;
213 		return;
214 	}
215 	/* Increase size if necessary */
216 	if (patterns == pattern_sz) {
217 		pattern_sz *= 2;
218 		pattern = grep_realloc(pattern, ++pattern_sz *
219 		    sizeof(struct pat));
220 	}
221 	if (len > 0 && pat[len - 1] == '\n')
222 		--len;
223 	/* pat may not be NUL-terminated */
224 	pattern[patterns].pat = grep_malloc(len + 1);
225 	memcpy(pattern[patterns].pat, pat, len);
226 	pattern[patterns].len = len;
227 	pattern[patterns].pat[len] = '\0';
228 	++patterns;
229 }
230 
231 /*
232  * Adds a file include/exclude pattern to the internal array.
233  */
234 static void
add_fpattern(const char * pat,int mode)235 add_fpattern(const char *pat, int mode)
236 {
237 
238 	/* Increase size if necessary */
239 	if (fpatterns == fpattern_sz) {
240 		fpattern_sz *= 2;
241 		fpattern = grep_realloc(fpattern, ++fpattern_sz *
242 		    sizeof(struct epat));
243 	}
244 	fpattern[fpatterns].pat = grep_strdup(pat);
245 	fpattern[fpatterns].mode = mode;
246 	++fpatterns;
247 }
248 
249 /*
250  * Adds a directory include/exclude pattern to the internal array.
251  */
252 static void
add_dpattern(const char * pat,int mode)253 add_dpattern(const char *pat, int mode)
254 {
255 
256 	/* Increase size if necessary */
257 	if (dpatterns == dpattern_sz) {
258 		dpattern_sz *= 2;
259 		dpattern = grep_realloc(dpattern, ++dpattern_sz *
260 		    sizeof(struct epat));
261 	}
262 	dpattern[dpatterns].pat = grep_strdup(pat);
263 	dpattern[dpatterns].mode = mode;
264 	++dpatterns;
265 }
266 
267 /*
268  * Reads searching patterns from a file and adds them with add_pattern().
269  */
270 static void
read_patterns(const char * fn)271 read_patterns(const char *fn)
272 {
273 	struct stat st;
274 	FILE *f;
275 	char *line;
276 	size_t len;
277 	ssize_t rlen;
278 
279 	if (strcmp(fn, "-") == 0)
280 		f = stdin;
281 	else if ((f = fopen(fn, "r")) == NULL)
282 		err(2, "%s", fn);
283 	if ((fstat(fileno(f), &st) == -1) || (S_ISDIR(st.st_mode))) {
284 		fclose(f);
285 		return;
286 	}
287 	len = 0;
288 	line = NULL;
289 	while ((rlen = getline(&line, &len, f)) != -1) {
290 		if (line[0] == '\0')
291 			continue;
292 		add_pattern(line, line[0] == '\n' ? 0 : (size_t)rlen);
293 	}
294 
295 	free(line);
296 	if (ferror(f))
297 		err(2, "%s", fn);
298 	if (strcmp(fn, "-") != 0)
299 		fclose(f);
300 }
301 
302 static inline const char *
init_color(const char * d)303 init_color(const char *d)
304 {
305 	char *c;
306 
307 	c = getenv("GREP_COLOR");
308 	return (c != NULL && c[0] != '\0' ? c : d);
309 }
310 
311 int
main(int argc,char * argv[])312 main(int argc, char *argv[])
313 {
314 	char **aargv, **eargv, *eopts;
315 	char *ep;
316 	const char *pn;
317 	long long l;
318 	unsigned int aargc, eargc, i;
319 	int c, lastc, needpattern, newarg, prevoptind;
320 	bool matched;
321 
322 	setlocale(LC_ALL, "");
323 
324 	/*
325 	 * Check how we've bene invoked to determine the behavior we should
326 	 * exhibit. In this way we can have all the functionalities in one
327 	 * binary without the need of scripting and using ugly hacks.
328 	 */
329 	pn = getprogname();
330 	switch (pn[0]) {
331 	case 'e':
332 		grepbehave = GREP_EXTENDED;
333 		break;
334 	case 'f':
335 		grepbehave = GREP_FIXED;
336 		break;
337 	case 'r':
338 		dirbehave = DIR_RECURSE;
339 		Hflag = true;
340 		break;
341 	}
342 
343 	lastc = '\0';
344 	newarg = 1;
345 	prevoptind = 1;
346 	needpattern = 1;
347 	fileeol = '\n';
348 
349 	eopts = getenv("GREP_OPTIONS");
350 
351 	/* support for extra arguments in GREP_OPTIONS */
352 	eargc = 0;
353 	if (eopts != NULL && eopts[0] != '\0') {
354 		char *str;
355 
356 		/* make an estimation of how many extra arguments we have */
357 		for (unsigned int j = 0; j < strlen(eopts); j++)
358 			if (eopts[j] == ' ')
359 				eargc++;
360 
361 		eargv = (char **)grep_malloc(sizeof(char *) * (eargc + 1));
362 
363 		eargc = 0;
364 		/* parse extra arguments */
365 		while ((str = strsep(&eopts, " ")) != NULL)
366 			if (str[0] != '\0')
367 				eargv[eargc++] = grep_strdup(str);
368 
369 		aargv = (char **)grep_calloc(eargc + argc + 1,
370 		    sizeof(char *));
371 
372 		aargv[0] = argv[0];
373 		for (i = 0; i < eargc; i++)
374 			aargv[i + 1] = eargv[i];
375 		for (int j = 1; j < argc; j++, i++)
376 			aargv[i + 1] = argv[j];
377 
378 		aargc = eargc + argc;
379 	} else {
380 		aargv = argv;
381 		aargc = argc;
382 	}
383 
384 	while (((c = getopt_long(aargc, aargv, optstr, long_options, NULL)) !=
385 	    -1)) {
386 		switch (c) {
387 		case '0': case '1': case '2': case '3': case '4':
388 		case '5': case '6': case '7': case '8': case '9':
389 			if (newarg || !isdigit(lastc))
390 				Aflag = 0;
391 			else if (Aflag > LLONG_MAX / 10 - 1) {
392 				errno = ERANGE;
393 				err(2, NULL);
394 			}
395 
396 			Aflag = Bflag = (Aflag * 10) + (c - '0');
397 			break;
398 		case 'C':
399 			if (optarg == NULL) {
400 				Aflag = Bflag = 2;
401 				break;
402 			}
403 			/* FALLTHROUGH */
404 		case 'A':
405 			/* FALLTHROUGH */
406 		case 'B':
407 			errno = 0;
408 			l = strtoll(optarg, &ep, 10);
409 			if (errno == ERANGE || errno == EINVAL)
410 				err(2, NULL);
411 			else if (ep[0] != '\0') {
412 				errno = EINVAL;
413 				err(2, NULL);
414 			} else if (l < 0) {
415 				errno = EINVAL;
416 				err(2, "context argument must be non-negative");
417 			}
418 
419 			if (c == 'A')
420 				Aflag = l;
421 			else if (c == 'B')
422 				Bflag = l;
423 			else
424 				Aflag = Bflag = l;
425 			break;
426 		case 'a':
427 			binbehave = BINFILE_TEXT;
428 			break;
429 		case 'b':
430 			bflag = true;
431 			break;
432 		case 'c':
433 			cflag = true;
434 			break;
435 		case 'D':
436 			if (strcasecmp(optarg, "skip") == 0)
437 				devbehave = DEV_SKIP;
438 			else if (strcasecmp(optarg, "read") == 0)
439 				devbehave = DEV_READ;
440 			else
441 				errx(2, errstr[2], "--devices");
442 			break;
443 		case 'd':
444 			if (strcasecmp("recurse", optarg) == 0) {
445 				Hflag = true;
446 				dirbehave = DIR_RECURSE;
447 			} else if (strcasecmp("skip", optarg) == 0)
448 				dirbehave = DIR_SKIP;
449 			else if (strcasecmp("read", optarg) == 0)
450 				dirbehave = DIR_READ;
451 			else
452 				errx(2, errstr[2], "--directories");
453 			break;
454 		case 'E':
455 			grepbehave = GREP_EXTENDED;
456 			break;
457 		case 'e':
458 			{
459 				char *token;
460 				char *string = optarg;
461 
462 				while ((token = strsep(&string, "\n")) != NULL)
463 					add_pattern(token, strlen(token));
464 			}
465 			needpattern = 0;
466 			break;
467 		case 'F':
468 			grepbehave = GREP_FIXED;
469 			break;
470 		case 'f':
471 			read_patterns(optarg);
472 			needpattern = 0;
473 			break;
474 		case 'G':
475 			grepbehave = GREP_BASIC;
476 			break;
477 		case 'H':
478 			Hflag = true;
479 			break;
480 		case 'h':
481 			Hflag = false;
482 			hflag = true;
483 			break;
484 		case 'I':
485 			binbehave = BINFILE_SKIP;
486 			break;
487 		case 'i':
488 		case 'y':
489 			iflag =  true;
490 			cflags |= REG_ICASE;
491 			break;
492 		case 'L':
493 			lflag = false;
494 			Lflag = true;
495 			break;
496 		case 'l':
497 			Lflag = false;
498 			lflag = true;
499 			break;
500 		case 'm':
501 			mflag = true;
502 			errno = 0;
503 			mlimit = mcount = strtoll(optarg, &ep, 10);
504 			if (((errno == ERANGE) && (mcount == LLONG_MAX)) ||
505 			    ((errno == EINVAL) && (mcount == 0)))
506 				err(2, NULL);
507 			else if (ep[0] != '\0') {
508 				errno = EINVAL;
509 				err(2, NULL);
510 			}
511 			break;
512 		case 'n':
513 			nflag = true;
514 			break;
515 		case 'O':
516 			linkbehave = LINK_EXPLICIT;
517 			break;
518 		case 'o':
519 			oflag = true;
520 			cflags &= ~REG_NOSUB;
521 			break;
522 		case 'p':
523 			linkbehave = LINK_SKIP;
524 			break;
525 		case 'q':
526 			qflag = true;
527 			break;
528 		case 'S':
529 			linkbehave = LINK_READ;
530 			break;
531 		case 'R':
532 		case 'r':
533 			dirbehave = DIR_RECURSE;
534 			Hflag = true;
535 			break;
536 		case 's':
537 			sflag = true;
538 			break;
539 		case 'U':
540 			binbehave = BINFILE_BIN;
541 			break;
542 		case 'u':
543 		case MMAP_OPT:
544 			filebehave = FILE_MMAP;
545 			break;
546 		case 'V':
547 			printf(errstr[8], getprogname(), VERSION);
548 			exit(0);
549 		case 'v':
550 			vflag = true;
551 			break;
552 		case 'w':
553 			wflag = true;
554 			cflags &= ~REG_NOSUB;
555 			break;
556 		case 'x':
557 			xflag = true;
558 			cflags &= ~REG_NOSUB;
559 			break;
560 		case 'z':
561 			fileeol = '\0';
562 			cflags &= ~REG_NEWLINE;
563 			break;
564 		case BIN_OPT:
565 			if (strcasecmp("binary", optarg) == 0)
566 				binbehave = BINFILE_BIN;
567 			else if (strcasecmp("without-match", optarg) == 0)
568 				binbehave = BINFILE_SKIP;
569 			else if (strcasecmp("text", optarg) == 0)
570 				binbehave = BINFILE_TEXT;
571 			else
572 				errx(2, errstr[2], "--binary-files");
573 			break;
574 		case COLOR_OPT:
575 			color = NULL;
576 			if (optarg == NULL || strcasecmp("auto", optarg) == 0 ||
577 			    strcasecmp("tty", optarg) == 0 ||
578 			    strcasecmp("if-tty", optarg) == 0) {
579 				char *term;
580 
581 				term = getenv("TERM");
582 				if (isatty(STDOUT_FILENO) && term != NULL &&
583 				    strcasecmp(term, "dumb") != 0)
584 					color = init_color("01;31");
585 			} else if (strcasecmp("always", optarg) == 0 ||
586 			    strcasecmp("yes", optarg) == 0 ||
587 			    strcasecmp("force", optarg) == 0) {
588 				color = init_color("01;31");
589 			} else if (strcasecmp("never", optarg) != 0 &&
590 			    strcasecmp("none", optarg) != 0 &&
591 			    strcasecmp("no", optarg) != 0)
592 				errx(2, errstr[2], "--color");
593 			cflags &= ~REG_NOSUB;
594 			break;
595 		case LABEL_OPT:
596 			label = optarg;
597 			break;
598 		case LINEBUF_OPT:
599 			lbflag = true;
600 			break;
601 		case NULL_OPT:
602 			nullflag = true;
603 			break;
604 		case R_INCLUDE_OPT:
605 			finclude = true;
606 			add_fpattern(optarg, INCL_PAT);
607 			break;
608 		case R_EXCLUDE_OPT:
609 			fexclude = true;
610 			add_fpattern(optarg, EXCL_PAT);
611 			break;
612 		case R_DINCLUDE_OPT:
613 			dinclude = true;
614 			add_dpattern(optarg, INCL_PAT);
615 			break;
616 		case R_DEXCLUDE_OPT:
617 			dexclude = true;
618 			add_dpattern(optarg, EXCL_PAT);
619 			break;
620 		case HELP_OPT:
621 		default:
622 			usage();
623 		}
624 		lastc = c;
625 		newarg = optind != prevoptind;
626 		prevoptind = optind;
627 	}
628 	aargc -= optind;
629 	aargv += optind;
630 
631 	/* xflag takes precedence, don't confuse the matching bits. */
632 	if (wflag && xflag)
633 		wflag = false;
634 
635 	/* Fail if we don't have any pattern */
636 	if (aargc == 0 && needpattern)
637 		usage();
638 
639 	/* Process patterns from command line */
640 	if (aargc != 0 && needpattern) {
641 		char *token;
642 		char *string = *aargv;
643 
644 		while ((token = strsep(&string, "\n")) != NULL)
645 			add_pattern(token, strlen(token));
646 		--aargc;
647 		++aargv;
648 	}
649 
650 	switch (grepbehave) {
651 	case GREP_BASIC:
652 		break;
653 	case GREP_FIXED:
654 		/*
655 		 * regex(3) implementations that support fixed-string searches generally
656 		 * define either REG_NOSPEC or REG_LITERAL. Set the appropriate flag
657 		 * here. If neither are defined, GREP_FIXED later implies that the
658 		 * internal literal matcher should be used. Other cflags that have
659 		 * the same interpretation as REG_NOSPEC and REG_LITERAL should be
660 		 * similarly added here, and grep.h should be amended to take this into
661 		 * consideration when defining WITH_INTERNAL_NOSPEC.
662 		 */
663 #if defined(REG_NOSPEC)
664 		cflags |= REG_NOSPEC;
665 #elif defined(REG_LITERAL)
666 		cflags |= REG_LITERAL;
667 #endif
668 		break;
669 	case GREP_EXTENDED:
670 		cflags |= REG_EXTENDED;
671 		break;
672 	default:
673 		/* NOTREACHED */
674 		usage();
675 	}
676 
677 	r_pattern = grep_calloc(patterns, sizeof(*r_pattern));
678 
679 #ifdef WITH_INTERNAL_NOSPEC
680 	if (grepbehave != GREP_FIXED) {
681 #else
682 	{
683 #endif
684 		/* Check if cheating is allowed (always is for fgrep). */
685 		for (i = 0; i < patterns; ++i) {
686 			c = regcomp(&r_pattern[i], pattern[i].pat, cflags);
687 			if (c != 0) {
688 				regerror(c, &r_pattern[i], re_error,
689 				    RE_ERROR_BUF);
690 				errx(2, "%s", re_error);
691 			}
692 		}
693 	}
694 
695 	if (lbflag)
696 		setlinebuf(stdout);
697 
698 	if ((aargc == 0 || aargc == 1) && !Hflag)
699 		hflag = true;
700 
701 	initqueue();
702 
703 	if (aargc == 0 && dirbehave != DIR_RECURSE)
704 		exit(!procfile("-"));
705 
706 	if (dirbehave == DIR_RECURSE)
707 		matched = grep_tree(aargv);
708 	else
709 		for (matched = false; aargc--; ++aargv) {
710 			if ((finclude || fexclude) && !file_matching(*aargv))
711 				continue;
712 			if (procfile(*aargv))
713 				matched = true;
714 		}
715 
716 	if (Lflag)
717 		matched = !matched;
718 
719 	/*
720 	 * Calculate the correct return value according to the
721 	 * results and the command line option.
722 	 */
723 	exit(matched ? (file_err ? (qflag ? 0 : 2) : 0) : (file_err ? 2 : 1));
724 }
725