xref: /freebsd/contrib/file/src/file.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*
2  * Copyright (c) Ian F. Darwin 1986-1995.
3  * Software written by Ian F. Darwin and others;
4  * maintained 1995-present by Christos Zoulas and others.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice immediately at the beginning of the file, without modification,
11  *    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 FOR
20  * 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  * file - find type of a file or files - main program.
30  */
31 
32 #include "file.h"
33 
34 #ifndef	lint
35 FILE_RCSID("@(#)$File: file.c,v 1.215 2023/05/21 17:08:34 christos Exp $")
36 #endif	/* lint */
37 
38 #include "magic.h"
39 
40 #include <stdlib.h>
41 #include <unistd.h>
42 #include <string.h>
43 #ifdef RESTORE_TIME
44 # if (__COHERENT__ >= 0x420)
45 #  include <sys/utime.h>
46 # else
47 #  ifdef USE_UTIMES
48 #   include <sys/time.h>
49 #  else
50 #   include <utime.h>
51 #  endif
52 # endif
53 #endif
54 #ifdef HAVE_UNISTD_H
55 #include <unistd.h>	/* for read() */
56 #endif
57 #ifdef HAVE_WCHAR_H
58 #include <wchar.h>
59 #endif
60 #ifdef HAVE_WCTYPE_H
61 #include <wctype.h>
62 #endif
63 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH) && \
64    defined(HAVE_WCTYPE_H)
65 #define FILE_WIDE_SUPPORT
66 #else
67 #include <ctype.h>
68 #endif
69 
70 #if defined(HAVE_GETOPT_H) && defined(HAVE_STRUCT_OPTION)
71 # include <getopt.h>
72 # ifndef HAVE_GETOPT_LONG
73 int getopt_long(int, char * const *, const char *,
74     const struct option *, int *);
75 # endif
76 # else
77 #  include "mygetopt.h"
78 #endif
79 
80 #ifdef S_IFLNK
81 # define IFLNK_h "h"
82 # define IFLNK_L "L"
83 #else
84 # define IFLNK_h ""
85 # define IFLNK_L ""
86 #endif
87 
88 #define FILE_FLAGS	"bcCdE" IFLNK_h "ik" IFLNK_L "lNnprsSvzZ0"
89 #define OPTSTRING	"bcCde:Ef:F:hiklLm:nNpP:rsSvzZ0"
90 
91 # define USAGE  \
92     "Usage: %s [-" FILE_FLAGS "] [--apple] [--extension] [--mime-encoding]\n" \
93     "            [--mime-type] [-e <testname>] [-F <separator>] " \
94     " [-f <namefile>]\n" \
95     "            [-m <magicfiles>] [-P <parameter=value>] [--exclude-quiet]\n" \
96     "            <file> ...\n" \
97     "       %s -C [-m <magicfiles>]\n" \
98     "       %s [--help]\n"
99 
100 file_private int 		/* Global command-line options 		*/
101 	bflag = 0,	/* brief output format	 		*/
102 	nopad = 0,	/* Don't pad output			*/
103 	nobuffer = 0,   /* Do not buffer stdout 		*/
104 	nulsep = 0;	/* Append '\0' to the separator		*/
105 
106 file_private const char *separator = ":";	/* Default field separator	*/
107 file_private const struct option long_options[] = {
108 #define OPT_HELP		1
109 #define OPT_APPLE		2
110 #define OPT_EXTENSIONS		3
111 #define OPT_MIME_TYPE		4
112 #define OPT_MIME_ENCODING	5
113 #define OPT_EXCLUDE_QUIET	6
114 #define OPT(shortname, longname, opt, def, doc)		\
115     {longname, opt, NULL, shortname},
116 #define OPT_LONGONLY(longname, opt, def, doc, id)	\
117     {longname, opt, NULL, id},
118 #include "file_opts.h"
119 #undef OPT
120 #undef OPT_LONGONLY
121     {0, 0, NULL, 0}
122     };
123 
124 file_private const struct {
125 	const char *name;
126 	int value;
127 } nv[] = {
128 	{ "apptype",	MAGIC_NO_CHECK_APPTYPE },
129 	{ "ascii",	MAGIC_NO_CHECK_ASCII },
130 	{ "cdf",	MAGIC_NO_CHECK_CDF },
131 	{ "compress",	MAGIC_NO_CHECK_COMPRESS },
132 	{ "csv",	MAGIC_NO_CHECK_CSV },
133 	{ "elf",	MAGIC_NO_CHECK_ELF },
134 	{ "encoding",	MAGIC_NO_CHECK_ENCODING },
135 	{ "soft",	MAGIC_NO_CHECK_SOFT },
136 	{ "tar",	MAGIC_NO_CHECK_TAR },
137 	{ "json",	MAGIC_NO_CHECK_JSON },
138 	{ "simh",	MAGIC_NO_CHECK_SIMH },
139 	{ "text",	MAGIC_NO_CHECK_TEXT },	/* synonym for ascii */
140 	{ "tokens",	MAGIC_NO_CHECK_TOKENS }, /* OBSOLETE: ignored for backwards compatibility */
141 };
142 
143 file_private struct {
144 	const char *name;
145 	size_t value;
146 	size_t def;
147 	const char *desc;
148 	int tag;
149 	int set;
150 } pm[] = {
151 	{ "bytes", 0, FILE_BYTES_MAX, "max bytes to look inside file",
152 	    MAGIC_PARAM_BYTES_MAX, 0 },
153 	{ "elf_notes", 0, FILE_ELF_NOTES_MAX, "max ELF notes processed",
154 	    MAGIC_PARAM_ELF_NOTES_MAX, 0 },
155 	{ "elf_phnum", 0, FILE_ELF_PHNUM_MAX, "max ELF prog sections processed",
156 	    MAGIC_PARAM_ELF_PHNUM_MAX, 0 },
157 	{ "elf_shnum", 0, FILE_ELF_SHNUM_MAX, "max ELF sections processed",
158 	    MAGIC_PARAM_ELF_SHNUM_MAX, 0 },
159 	{ "elf_shsize", 0, FILE_ELF_SHSIZE_MAX, "max ELF section size",
160 	    MAGIC_PARAM_ELF_SHSIZE_MAX, 0 },
161 	{ "encoding", 0, FILE_ENCODING_MAX, "max bytes to scan for encoding",
162 	    MAGIC_PARAM_ENCODING_MAX, 0 },
163 	{ "indir", 0, FILE_INDIR_MAX, "recursion limit for indirection",
164 	    MAGIC_PARAM_INDIR_MAX, 0 },
165 	{ "name", 0, FILE_NAME_MAX, "use limit for name/use magic",
166 	    MAGIC_PARAM_NAME_MAX, 0 },
167 	{ "regex", 0, FILE_REGEX_MAX, "length limit for REGEX searches",
168 	    MAGIC_PARAM_REGEX_MAX, 0 },
169 };
170 
171 file_private int posixly;
172 
173 #ifdef __dead
174 __dead
175 #endif
176 file_private void usage(void);
177 file_private void docprint(const char *, int);
178 #ifdef __dead
179 __dead
180 #endif
181 file_private void help(void);
182 
183 file_private int unwrap(struct magic_set *, const char *);
184 file_private int process(struct magic_set *ms, const char *, int);
185 file_private struct magic_set *load(const char *, int);
186 file_private void setparam(const char *);
187 file_private void applyparam(magic_t);
188 
189 
190 /*
191  * main - parse arguments and handle options
192  */
193 int
194 main(int argc, char *argv[])
195 {
196 	int c;
197 	size_t i, j, wid, nw;
198 	int action = 0, didsomefiles = 0, errflg = 0;
199 	int flags = 0, e = 0;
200 #ifdef HAVE_LIBSECCOMP
201 	int sandbox = 1;
202 #endif
203 	struct magic_set *magic = NULL;
204 	int longindex;
205 	const char *magicfile = NULL;		/* where the magic is	*/
206 	char *progname;
207 
208 	/* makes islower etc work for other langs */
209 	(void)setlocale(LC_CTYPE, "");
210 
211 #ifdef __EMX__
212 	/* sh-like wildcard expansion! Shouldn't hurt at least ... */
213 	_wildcard(&argc, &argv);
214 #endif
215 
216 	if ((progname = strrchr(argv[0], '/')) != NULL)
217 		progname++;
218 	else
219 		progname = argv[0];
220 
221 	file_setprogname(progname);
222 
223 
224 #ifdef S_IFLNK
225 	posixly = getenv("POSIXLY_CORRECT") != NULL;
226 	flags |=  posixly ? MAGIC_SYMLINK : 0;
227 #endif
228 	while ((c = getopt_long(argc, argv, OPTSTRING, long_options,
229 	    &longindex)) != -1)
230 		switch (c) {
231 		case OPT_HELP:
232 			help();
233 			break;
234 		case OPT_APPLE:
235 			flags |= MAGIC_APPLE;
236 			break;
237 		case OPT_EXTENSIONS:
238 			flags |= MAGIC_EXTENSION;
239 			break;
240 		case OPT_MIME_TYPE:
241 			flags |= MAGIC_MIME_TYPE;
242 			break;
243 		case OPT_MIME_ENCODING:
244 			flags |= MAGIC_MIME_ENCODING;
245 			break;
246 		case '0':
247 			nulsep++;
248 			break;
249 		case 'b':
250 			bflag++;
251 			break;
252 		case 'c':
253 			action = FILE_CHECK;
254 			break;
255 		case 'C':
256 			action = FILE_COMPILE;
257 			break;
258 		case 'd':
259 			flags |= MAGIC_DEBUG|MAGIC_CHECK;
260 			break;
261 		case 'E':
262 			flags |= MAGIC_ERROR;
263 			break;
264 		case 'e':
265 		case OPT_EXCLUDE_QUIET:
266 			for (i = 0; i < __arraycount(nv); i++)
267 				if (strcmp(nv[i].name, optarg) == 0)
268 					break;
269 
270 			if (i == __arraycount(nv)) {
271 				if (c != OPT_EXCLUDE_QUIET)
272 					errflg++;
273 			} else
274 				flags |= nv[i].value;
275 			break;
276 
277 		case 'f':
278 			if(action)
279 				usage();
280 			if (magic == NULL)
281 				if ((magic = load(magicfile, flags)) == NULL)
282 					return 1;
283 			applyparam(magic);
284 			e |= unwrap(magic, optarg);
285 			++didsomefiles;
286 			break;
287 		case 'F':
288 			separator = optarg;
289 			break;
290 		case 'i':
291 			flags |= MAGIC_MIME;
292 			break;
293 		case 'k':
294 			flags |= MAGIC_CONTINUE;
295 			break;
296 		case 'l':
297 			action = FILE_LIST;
298 			break;
299 		case 'm':
300 			magicfile = optarg;
301 			break;
302 		case 'n':
303 			++nobuffer;
304 			break;
305 		case 'N':
306 			++nopad;
307 			break;
308 #if defined(HAVE_UTIME) || defined(HAVE_UTIMES)
309 		case 'p':
310 			flags |= MAGIC_PRESERVE_ATIME;
311 			break;
312 #endif
313 		case 'P':
314 			setparam(optarg);
315 			break;
316 		case 'r':
317 			flags |= MAGIC_RAW;
318 			break;
319 		case 's':
320 			flags |= MAGIC_DEVICES;
321 			break;
322 		case 'S':
323 #ifdef HAVE_LIBSECCOMP
324 			sandbox = 0;
325 #endif
326 			break;
327 		case 'v':
328 			if (magicfile == NULL)
329 				magicfile = magic_getpath(magicfile, action);
330 			(void)fprintf(stdout, "%s-%s\n", file_getprogname(),
331 			    VERSION);
332 			(void)fprintf(stdout, "magic file from %s\n",
333 			    magicfile);
334 #ifdef HAVE_LIBSECCOMP
335 			(void)fprintf(stdout, "seccomp support included\n");
336 #endif
337 			return 0;
338 		case 'z':
339 			flags |= MAGIC_COMPRESS;
340 			break;
341 
342 		case 'Z':
343 			flags |= MAGIC_COMPRESS|MAGIC_COMPRESS_TRANSP;
344 			break;
345 #ifdef S_IFLNK
346 		case 'L':
347 			flags |= MAGIC_SYMLINK;
348 			break;
349 		case 'h':
350 			flags &= ~MAGIC_SYMLINK;
351 			break;
352 #endif
353 		case '?':
354 		default:
355 			errflg++;
356 			break;
357 		}
358 
359 	if (errflg) {
360 		usage();
361 	}
362 	if (e)
363 		return e;
364 
365 #ifdef HAVE_LIBSECCOMP
366 #if 0
367 	if (sandbox && enable_sandbox_basic() == -1)
368 #else
369 	if (sandbox && enable_sandbox_full() == -1)
370 #endif
371 		file_err(EXIT_FAILURE, "SECCOMP initialisation failed");
372 	if (sandbox)
373 		flags |= MAGIC_NO_COMPRESS_FORK;
374 #endif /* HAVE_LIBSECCOMP */
375 
376 	if (MAGIC_VERSION != magic_version())
377 		file_warnx("Compiled magic version [%d] "
378 		    "does not match with shared library magic version [%d]\n",
379 		    MAGIC_VERSION, magic_version());
380 
381 	switch(action) {
382 	case FILE_CHECK:
383 	case FILE_COMPILE:
384 	case FILE_LIST:
385 		/*
386 		 * Don't try to check/compile ~/.magic unless we explicitly
387 		 * ask for it.
388 		 */
389 		magic = magic_open(flags|MAGIC_CHECK);
390 		if (magic == NULL) {
391 			file_warn("Can't create magic");
392 			return 1;
393 		}
394 
395 
396 		switch(action) {
397 		case FILE_CHECK:
398 			c = magic_check(magic, magicfile);
399 			break;
400 		case FILE_COMPILE:
401 			c = magic_compile(magic, magicfile);
402 			break;
403 		case FILE_LIST:
404 			c = magic_list(magic, magicfile);
405 			break;
406 		default:
407 			abort();
408 		}
409 		if (c == -1) {
410 			file_warnx("%s", magic_error(magic));
411 			e = 1;
412 			goto out;
413 		}
414 		goto out;
415 	default:
416 		if (magic == NULL)
417 			if ((magic = load(magicfile, flags)) == NULL)
418 				return 1;
419 		applyparam(magic);
420 	}
421 
422 	if (optind == argc) {
423 		if (!didsomefiles)
424 			usage();
425 		goto out;
426 	}
427 
428 	for (wid = 0, j = CAST(size_t, optind); j < CAST(size_t, argc);
429 	    j++) {
430 		nw = file_mbswidth(magic, argv[j]);
431 		if (nw > wid)
432 			wid = nw;
433 	}
434 
435 	/*
436 	 * If bflag is only set twice, set it depending on
437 	 * number of files [this is undocumented, and subject to change]
438 	 */
439 	if (bflag == 2) {
440 		bflag = optind >= argc - 1;
441 	}
442 	for (; optind < argc; optind++)
443 		e |= process(magic, argv[optind], wid);
444 
445 out:
446 	if (!nobuffer)
447 		e |= fflush(stdout) != 0;
448 
449 	if (magic)
450 		magic_close(magic);
451 	return e;
452 }
453 
454 file_private void
455 applyparam(magic_t magic)
456 {
457 	size_t i;
458 
459 	for (i = 0; i < __arraycount(pm); i++) {
460 		if (!pm[i].set)
461 			continue;
462 		if (magic_setparam(magic, pm[i].tag, &pm[i].value) == -1)
463 			file_err(EXIT_FAILURE, "Can't set %s", pm[i].name);
464 	}
465 }
466 
467 file_private void
468 setparam(const char *p)
469 {
470 	size_t i;
471 	char *s;
472 
473 	if ((s = CCAST(char *, strchr(p, '='))) == NULL)
474 		goto badparm;
475 
476 	for (i = 0; i < __arraycount(pm); i++) {
477 		if (strncmp(p, pm[i].name, s - p) != 0)
478 			continue;
479 		pm[i].value = atoi(s + 1);
480 		pm[i].set = 1;
481 		return;
482 	}
483 badparm:
484 	file_errx(EXIT_FAILURE, "Unknown param %s", p);
485 }
486 
487 file_private struct magic_set *
488 /*ARGSUSED*/
489 load(const char *magicfile, int flags)
490 {
491 	struct magic_set *magic = magic_open(flags);
492 	const char *e;
493 
494 	if (magic == NULL) {
495 		file_warn("Can't create magic");
496 		return NULL;
497 	}
498 	if (magic_load(magic, magicfile) == -1) {
499 		file_warn("%s", magic_error(magic));
500 		magic_close(magic);
501 		return NULL;
502 	}
503 	if ((e = magic_error(magic)) != NULL)
504 		file_warn("%s", e);
505 	return magic;
506 }
507 
508 /*
509  * unwrap -- read a file of filenames, do each one.
510  */
511 file_private int
512 unwrap(struct magic_set *ms, const char *fn)
513 {
514 	FILE *f;
515 	ssize_t len;
516 	char *line = NULL;
517 	size_t llen = 0;
518 	int wid = 0, cwid;
519 	int e = 0;
520 	size_t fi = 0, fimax = 0;
521 	char **flist = NULL;
522 
523 	if (strcmp("-", fn) == 0)
524 		f = stdin;
525 	else {
526 		if ((f = fopen(fn, "r")) == NULL) {
527 			file_warn("Cannot open `%s'", fn);
528 			return 1;
529 		}
530 	}
531 
532 	while ((len = getline(&line, &llen, f)) > 0) {
533 		if (line[len - 1] == '\n')
534 			line[len - 1] = '\0';
535 		cwid = file_mbswidth(ms, line);
536 		if (nobuffer) {
537 			e |= process(ms, line, cwid);
538 			free(line);
539 			line = NULL;
540 			llen = 0;
541 			continue;
542 		}
543 		if (cwid > wid)
544 			wid = cwid;
545 		if (fi >= fimax) {
546 			fimax += 100;
547 			char **nf = CAST(char **,
548 			    realloc(flist, fimax * sizeof(*flist)));
549 			if (nf == NULL) {
550 				file_err(EXIT_FAILURE,
551 				    "Cannot allocate memory for file list");
552 			}
553 			flist = nf;
554 		}
555 		flist[fi++] = line;
556 		line = NULL;
557 		llen = 0;
558 	}
559 
560 	if (!nobuffer) {
561 		fimax = fi;
562 		for (fi = 0; fi < fimax; fi++) {
563 			e |= process(ms, flist[fi], wid);
564 			free(flist[fi]);
565 		}
566 	}
567 	free(flist);
568 
569 	if (f != stdin)
570 		(void)fclose(f);
571 	return e;
572 }
573 
574 file_private void
575 file_octal(unsigned char c)
576 {
577 	(void)putc('\\', stdout);
578 	(void)putc(((c >> 6) & 7) + '0', stdout);
579 	(void)putc(((c >> 3) & 7) + '0', stdout);
580 	(void)putc(((c >> 0) & 7) + '0', stdout);
581 }
582 
583 file_private void
584 fname_print(const char *inname)
585 {
586 	size_t n = strlen(inname);
587 #ifdef FILE_WIDE_SUPPORT
588 	mbstate_t state;
589 	wchar_t nextchar;
590 	size_t bytesconsumed;
591 
592 
593 	(void)memset(&state, 0, sizeof(state));
594 	while (n > 0) {
595 		bytesconsumed = mbrtowc(&nextchar, inname, n, &state);
596 		if (bytesconsumed == CAST(size_t, -1) ||
597 		    bytesconsumed == CAST(size_t, -2))  {
598 			nextchar = *inname++;
599 			n--;
600 			(void)memset(&state, 0, sizeof(state));
601 			file_octal(CAST(unsigned char, nextchar));
602 			continue;
603 		}
604 		inname += bytesconsumed;
605 		n -= bytesconsumed;
606 		if (iswprint(nextchar)) {
607 			printf("%lc", (wint_t)nextchar);
608 			continue;
609 		}
610 		/* XXX: What if it is > 255? */
611 		file_octal(CAST(unsigned char, nextchar));
612 	}
613 #else
614 	size_t i;
615 	for (i = 0; i < n; i++) {
616 		unsigned char c = CAST(unsigned char, inname[i]);
617 		if (isprint(c)) {
618 			(void)putc(c, stdout);
619 			continue;
620 		}
621 		file_octal(c);
622 	}
623 #endif
624 }
625 
626 /*
627  * Called for each input file on the command line (or in a list of files)
628  */
629 file_private int
630 process(struct magic_set *ms, const char *inname, int wid)
631 {
632 	const char *type, c = nulsep > 1 ? '\0' : '\n';
633 	int std_in = strcmp(inname, "-") == 0;
634 	int haderror = 0;
635 
636 	if (wid > 0 && !bflag) {
637 		const char *pname = std_in ? "/dev/stdin" : inname;
638 		if ((ms->flags & MAGIC_RAW) == 0)
639 			fname_print(pname);
640 		else
641 			(void)printf("%s", pname);
642 		if (nulsep)
643 			(void)putc('\0', stdout);
644 		if (nulsep < 2) {
645 			(void)printf("%s", separator);
646 			(void)printf("%*s ", CAST(int, nopad ? 0
647 			    : (wid - file_mbswidth(ms, inname))), "");
648 		}
649 	}
650 
651 	type = magic_file(ms, std_in ? NULL : inname);
652 
653 	if (type == NULL) {
654 		haderror |= printf("ERROR: %s%c", magic_error(ms), c);
655 	} else {
656 		haderror |= printf("%s%c", type, c) < 0;
657 	}
658 	if (nobuffer)
659 		haderror |= fflush(stdout) != 0;
660 	return haderror || type == NULL;
661 }
662 
663 file_protected size_t
664 file_mbswidth(struct magic_set *ms, const char *s)
665 {
666 	size_t width = 0;
667 #ifdef FILE_WIDE_SUPPORT
668 	size_t bytesconsumed, n;
669 	mbstate_t state;
670 	wchar_t nextchar;
671 
672 	(void)memset(&state, 0, sizeof(state));
673 	n = strlen(s);
674 
675 	while (n > 0) {
676 		bytesconsumed = mbrtowc(&nextchar, s, n, &state);
677 		if (bytesconsumed == CAST(size_t, -1) ||
678 		    bytesconsumed == CAST(size_t, -2)) {
679 			nextchar = *s;
680 			bytesconsumed = 1;
681 			(void)memset(&state, 0, sizeof(state));
682 			width += 4;
683 		} else {
684 			int w = wcwidth(nextchar);
685 			width += ((ms->flags & MAGIC_RAW) != 0
686 			    || iswprint(nextchar)) ? (w > 0 ? w : 1) : 4;
687 		}
688 
689 		s += bytesconsumed, n -= bytesconsumed;
690 	}
691 #else
692 	for (; *s; s++) {
693 		width += (ms->flags & MAGIC_RAW) != 0
694 		    || isprint(CAST(unsigned char, *s)) ? 1 : 4;
695 	}
696 #endif
697 	return width;
698 }
699 
700 file_private void
701 usage(void)
702 {
703 	const char *pn = file_getprogname();
704 	(void)fprintf(stderr, USAGE, pn, pn, pn);
705 	exit(EXIT_FAILURE);
706 }
707 
708 file_private void
709 defprint(int def)
710 {
711 	if (!def)
712 		return;
713 	if (((def & 1) && posixly) || ((def & 2) && !posixly))
714 		(void)fprintf(stdout, " (default)");
715 	(void)putc('\n', stdout);
716 }
717 
718 file_private void
719 docprint(const char *opts, int def)
720 {
721 	size_t i;
722 	int comma, pad;
723 	char *sp, *p;
724 
725 	p = CCAST(char *, strchr(opts, '%'));
726 	if (p == NULL) {
727 		(void)fprintf(stdout, "%s", opts);
728 		defprint(def);
729 		return;
730 	}
731 
732 	for (sp = p - 1; sp > opts && *sp == ' '; sp--)
733 		continue;
734 
735 	(void)printf("%.*s", CAST(int, p - opts), opts);
736 	pad = (int)CAST(int, p - sp - 1);
737 
738 	switch (*++p) {
739 	case 'e':
740 		comma = 0;
741 		for (i = 0; i < __arraycount(nv); i++) {
742 			(void)printf("%s%s", comma++ ? ", " : "", nv[i].name);
743 			if (i && i % 5 == 0 && i != __arraycount(nv) - 1) {
744 				(void)printf(",\n%*s", pad, "");
745 				comma = 0;
746 			}
747 		}
748 		break;
749 	case 'P':
750 		for (i = 0; i < __arraycount(pm); i++) {
751 			(void)printf("%9s %7zu %s", pm[i].name, pm[i].def,
752 			    pm[i].desc);
753 			if (i != __arraycount(pm) - 1)
754 				(void)printf("\n%*s", pad, "");
755 		}
756 		break;
757 	default:
758 		file_errx(EXIT_FAILURE, "Unknown escape `%c' in long options",
759 		   *p);
760 		break;
761 	}
762 	(void)printf("%s", opts + (p - opts) + 1);
763 
764 }
765 
766 file_private void
767 help(void)
768 {
769 	(void)fputs(
770 "Usage: file [OPTION...] [FILE...]\n"
771 "Determine type of FILEs.\n"
772 "\n", stdout);
773 #define OPT(shortname, longname, opt, def, doc)      \
774 	(void)printf("  -%c, --" longname, shortname), \
775 	docprint(doc, def);
776 #define OPT_LONGONLY(longname, opt, def, doc, id)    	\
777 	(void)printf("      --" longname),	\
778 	docprint(doc, def);
779 #include "file_opts.h"
780 #undef OPT
781 #undef OPT_LONGONLY
782 	(void)printf("\nReport bugs to https://bugs.astron.com/\n");
783 	exit(EXIT_SUCCESS);
784 }
785 
786 file_private const char *file_progname;
787 
788 file_protected void
789 file_setprogname(const char *progname)
790 {
791 	file_progname = progname;
792 }
793 
794 file_protected const char *
795 file_getprogname(void)
796 {
797 	return file_progname;
798 }
799 
800 file_protected void
801 file_err(int e, const char *fmt, ...)
802 {
803 	va_list ap;
804 	int se = errno;
805 
806 	va_start(ap, fmt);
807 	(void)fprintf(stderr, "%s: ", file_progname);
808 	(void)vfprintf(stderr, fmt, ap);
809 	va_end(ap);
810 	if (se)
811 		(void)fprintf(stderr, " (%s)\n", strerror(se));
812 	else
813 		fputc('\n', stderr);
814 	exit(e);
815 }
816 
817 file_protected void
818 file_errx(int e, const char *fmt, ...)
819 {
820 	va_list ap;
821 
822 	va_start(ap, fmt);
823 	(void)fprintf(stderr, "%s: ", file_progname);
824 	(void)vfprintf(stderr, fmt, ap);
825 	va_end(ap);
826 	(void)fprintf(stderr, "\n");
827 	exit(e);
828 }
829 
830 file_protected void
831 file_warn(const char *fmt, ...)
832 {
833 	va_list ap;
834 	int se = errno;
835 
836 	va_start(ap, fmt);
837 	(void)fprintf(stderr, "%s: ", file_progname);
838 	(void)vfprintf(stderr, fmt, ap);
839 	va_end(ap);
840 	if (se)
841 		(void)fprintf(stderr, " (%s)\n", strerror(se));
842 	else
843 		fputc('\n', stderr);
844 	errno = se;
845 }
846 
847 file_protected void
848 file_warnx(const char *fmt, ...)
849 {
850 	va_list ap;
851 	int se = errno;
852 
853 	va_start(ap, fmt);
854 	(void)fprintf(stderr, "%s: ", file_progname);
855 	(void)vfprintf(stderr, fmt, ap);
856 	va_end(ap);
857 	(void)fprintf(stderr, "\n");
858 	errno = se;
859 }
860