xref: /freebsd/usr.bin/diff/diff.c (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*	$OpenBSD: diff.c,v 1.67 2019/06/28 13:35:00 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  *
18  * Sponsored in part by the Defense Advanced Research Projects
19  * Agency (DARPA) and Air Force Research Laboratory, Air Force
20  * Materiel Command, USAF, under agreement number F39502-99-1-0512.
21  */
22 
23 #include <sys/cdefs.h>
24 __FBSDID("$FreeBSD$");
25 
26 #include <sys/stat.h>
27 
28 #include <ctype.h>
29 #include <err.h>
30 #include <errno.h>
31 #include <getopt.h>
32 #include <stdlib.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <unistd.h>
36 #include <limits.h>
37 
38 #include "diff.h"
39 #include "xmalloc.h"
40 
41 int	 lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag, Wflag;
42 int	 diff_format, diff_context, status, ignore_file_case, suppress_common;
43 int	 tabsize = 8, width = 130;
44 char	*start, *ifdefname, *diffargs, *label[2], *ignore_pats;
45 char	*group_format = NULL;
46 struct stat stb1, stb2;
47 struct excludes *excludes_list;
48 regex_t	 ignore_re;
49 
50 #define	OPTIONS	"0123456789aBbC:cdD:efHhI:iL:lnNPpqrS:sTtU:uwW:X:x:y"
51 enum {
52 	OPT_TSIZE = CHAR_MAX + 1,
53 	OPT_STRIPCR,
54 	OPT_IGN_FN_CASE,
55 	OPT_NO_IGN_FN_CASE,
56 	OPT_NORMAL,
57 	OPT_HORIZON_LINES,
58 	OPT_CHANGED_GROUP_FORMAT,
59 	OPT_SUPPRESS_COMMON,
60 };
61 
62 static struct option longopts[] = {
63 	{ "text",			no_argument,		0,	'a' },
64 	{ "ignore-space-change",	no_argument,		0,	'b' },
65 	{ "context",			optional_argument,	0,	'C' },
66 	{ "ifdef",			required_argument,	0,	'D' },
67 	{ "minimal",			no_argument,		0,	'd' },
68 	{ "ed",				no_argument,		0,	'e' },
69 	{ "forward-ed",			no_argument,		0,	'f' },
70 	{ "speed-large-files",		no_argument,		NULL,	'H' },
71 	{ "ignore-blank-lines",		no_argument,		0,	'B' },
72 	{ "ignore-matching-lines",	required_argument,	0,	'I' },
73 	{ "ignore-case",		no_argument,		0,	'i' },
74 	{ "paginate",			no_argument,		NULL,	'l' },
75 	{ "label",			required_argument,	0,	'L' },
76 	{ "new-file",			no_argument,		0,	'N' },
77 	{ "rcs",			no_argument,		0,	'n' },
78 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
79 	{ "show-c-function",		no_argument,		0,	'p' },
80 	{ "brief",			no_argument,		0,	'q' },
81 	{ "recursive",			no_argument,		0,	'r' },
82 	{ "report-identical-files",	no_argument,		0,	's' },
83 	{ "starting-file",		required_argument,	0,	'S' },
84 	{ "expand-tabs",		no_argument,		0,	't' },
85 	{ "initial-tab",		no_argument,		0,	'T' },
86 	{ "unified",			optional_argument,	0,	'U' },
87 	{ "ignore-all-space",		no_argument,		0,	'w' },
88 	{ "width",			required_argument,	0,	'W' },
89 	{ "exclude",			required_argument,	0,	'x' },
90 	{ "exclude-from",		required_argument,	0,	'X' },
91 	{ "side-by-side",		no_argument,		NULL,	'y' },
92 	{ "ignore-file-name-case",	no_argument,		NULL,	OPT_IGN_FN_CASE },
93 	{ "horizon-lines",		required_argument,	NULL,	OPT_HORIZON_LINES },
94 	{ "no-ignore-file-name-case",	no_argument,		NULL,	OPT_NO_IGN_FN_CASE },
95 	{ "normal",			no_argument,		NULL,	OPT_NORMAL },
96 	{ "strip-trailing-cr",		no_argument,		NULL,	OPT_STRIPCR },
97 	{ "tabsize",			required_argument,	NULL,	OPT_TSIZE },
98 	{ "changed-group-format",	required_argument,	NULL,	OPT_CHANGED_GROUP_FORMAT},
99 	{ "suppress-common-lines",	no_argument,		NULL,	OPT_SUPPRESS_COMMON },
100 	{ NULL,				0,			0,	'\0'}
101 };
102 
103 void usage(void) __dead2;
104 void conflicting_format(void) __dead2;
105 void push_excludes(char *);
106 void push_ignore_pats(char *);
107 void read_excludes_file(char *file);
108 void set_argstr(char **, char **);
109 
110 int
111 main(int argc, char **argv)
112 {
113 	const char *errstr = NULL;
114 	char *ep, **oargv;
115 	long  l;
116 	int   ch, dflags, lastch, gotstdin, prevoptind, newarg;
117 
118 	oargv = argv;
119 	gotstdin = 0;
120 	dflags = 0;
121 	lastch = '\0';
122 	prevoptind = 1;
123 	newarg = 1;
124 	diff_context = 3;
125 	diff_format = D_UNSET;
126 #define	FORMAT_MISMATCHED(type)	\
127 	(diff_format != D_UNSET && diff_format != (type))
128 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
129 		switch (ch) {
130 		case '0': case '1': case '2': case '3': case '4':
131 		case '5': case '6': case '7': case '8': case '9':
132 			if (newarg)
133 				usage();	/* disallow -[0-9]+ */
134 			else if (lastch == 'c' || lastch == 'u')
135 				diff_context = 0;
136 			else if (!isdigit(lastch) || diff_context > INT_MAX / 10)
137 				usage();
138 			diff_context = (diff_context * 10) + (ch - '0');
139 			break;
140 		case 'a':
141 			dflags |= D_FORCEASCII;
142 			break;
143 		case 'b':
144 			dflags |= D_FOLDBLANKS;
145 			break;
146 		case 'C':
147 		case 'c':
148 			if (FORMAT_MISMATCHED(D_CONTEXT))
149 				conflicting_format();
150 			cflag = 1;
151 			diff_format = D_CONTEXT;
152 			if (optarg != NULL) {
153 				l = strtol(optarg, &ep, 10);
154 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
155 					usage();
156 				diff_context = (int)l;
157 			}
158 			break;
159 		case 'd':
160 			dflags |= D_MINIMAL;
161 			break;
162 		case 'D':
163 			if (FORMAT_MISMATCHED(D_IFDEF))
164 				conflicting_format();
165 			diff_format = D_IFDEF;
166 			ifdefname = optarg;
167 			break;
168 		case 'e':
169 			if (FORMAT_MISMATCHED(D_EDIT))
170 				conflicting_format();
171 			diff_format = D_EDIT;
172 			break;
173 		case 'f':
174 			if (FORMAT_MISMATCHED(D_REVERSE))
175 				conflicting_format();
176 			diff_format = D_REVERSE;
177 			break;
178 		case 'H':
179 			/* ignore but needed for compatibility with GNU diff */
180 			break;
181 		case 'h':
182 			/* silently ignore for backwards compatibility */
183 			break;
184 		case 'B':
185 			dflags |= D_SKIPBLANKLINES;
186 			break;
187 		case 'I':
188 			push_ignore_pats(optarg);
189 			break;
190 		case 'i':
191 			dflags |= D_IGNORECASE;
192 			break;
193 		case 'L':
194 			if (label[0] == NULL)
195 				label[0] = optarg;
196 			else if (label[1] == NULL)
197 				label[1] = optarg;
198 			else
199 				usage();
200 			break;
201 		case 'l':
202 			lflag = 1;
203 			break;
204 		case 'N':
205 			Nflag = 1;
206 			break;
207 		case 'n':
208 			if (FORMAT_MISMATCHED(D_NREVERSE))
209 				conflicting_format();
210 			diff_format = D_NREVERSE;
211 			break;
212 		case 'p':
213 			dflags |= D_PROTOTYPE;
214 			break;
215 		case 'P':
216 			Pflag = 1;
217 			break;
218 		case 'r':
219 			rflag = 1;
220 			break;
221 		case 'q':
222 			if (FORMAT_MISMATCHED(D_BRIEF))
223 				conflicting_format();
224 			diff_format = D_BRIEF;
225 			break;
226 		case 'S':
227 			start = optarg;
228 			break;
229 		case 's':
230 			sflag = 1;
231 			break;
232 		case 'T':
233 			Tflag = 1;
234 			break;
235 		case 't':
236 			dflags |= D_EXPANDTABS;
237 			break;
238 		case 'U':
239 		case 'u':
240 			if (FORMAT_MISMATCHED(D_UNIFIED))
241 				conflicting_format();
242 			diff_format = D_UNIFIED;
243 			if (optarg != NULL) {
244 				l = strtol(optarg, &ep, 10);
245 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
246 					usage();
247 				diff_context = (int)l;
248 			}
249 			break;
250 		case 'w':
251 			dflags |= D_IGNOREBLANKS;
252 			break;
253 		case 'W':
254 			Wflag = 1;
255 			width = (int) strtonum(optarg, 1, INT_MAX, &errstr);
256 			if (errstr) {
257 				warnx("Invalid argument for width");
258 				usage();
259 			}
260 			break;
261 		case 'X':
262 			read_excludes_file(optarg);
263 			break;
264 		case 'x':
265 			push_excludes(optarg);
266 			break;
267 		case 'y':
268 			if (FORMAT_MISMATCHED(D_SIDEBYSIDE))
269 				conflicting_format();
270 			diff_format = D_SIDEBYSIDE;
271 			break;
272 		case OPT_CHANGED_GROUP_FORMAT:
273 			if (FORMAT_MISMATCHED(D_GFORMAT))
274 				conflicting_format();
275 			diff_format = D_GFORMAT;
276 			group_format = optarg;
277 			break;
278 		case OPT_HORIZON_LINES:
279 			break; /* XXX TODO for compatibility with GNU diff3 */
280 		case OPT_IGN_FN_CASE:
281 			ignore_file_case = 1;
282 			break;
283 		case OPT_NO_IGN_FN_CASE:
284 			ignore_file_case = 0;
285 			break;
286 		case OPT_NORMAL:
287 			if (FORMAT_MISMATCHED(D_NORMAL))
288 				conflicting_format();
289 			diff_format = D_NORMAL;
290 			break;
291 		case OPT_TSIZE:
292 			tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr);
293 			if (errstr) {
294 				warnx("Invalid argument for tabsize");
295 				usage();
296 			}
297 			break;
298 		case OPT_STRIPCR:
299 			dflags |= D_STRIPCR;
300 			break;
301 		case OPT_SUPPRESS_COMMON:
302 			suppress_common = 1;
303 			break;
304 		default:
305 			usage();
306 			break;
307 		}
308 		lastch = ch;
309 		newarg = optind != prevoptind;
310 		prevoptind = optind;
311 	}
312 	if (diff_format == D_UNSET && (dflags & D_PROTOTYPE) != 0)
313 		diff_format = D_CONTEXT;
314 	if (diff_format == D_UNSET)
315 		diff_format = D_NORMAL;
316 	argc -= optind;
317 	argv += optind;
318 
319 #ifdef __OpenBSD__
320 	if (pledge("stdio rpath tmppath", NULL) == -1)
321 		err(2, "pledge");
322 #endif
323 
324 	/*
325 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
326 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
327 	 */
328 	if (argc != 2)
329 		usage();
330 	if (ignore_pats != NULL) {
331 		char buf[BUFSIZ];
332 		int error;
333 
334 		if ((error = regcomp(&ignore_re, ignore_pats,
335 				     REG_NEWLINE | REG_EXTENDED)) != 0) {
336 			regerror(error, &ignore_re, buf, sizeof(buf));
337 			if (*ignore_pats != '\0')
338 				errx(2, "%s: %s", ignore_pats, buf);
339 			else
340 				errx(2, "%s", buf);
341 		}
342 	}
343 	if (strcmp(argv[0], "-") == 0) {
344 		fstat(STDIN_FILENO, &stb1);
345 		gotstdin = 1;
346 	} else if (stat(argv[0], &stb1) != 0) {
347 		if (!Nflag || errno != ENOENT)
348 			err(2, "%s", argv[0]);
349 		dflags |= D_EMPTY1;
350 		memset(&stb1, 0, sizeof(struct stat));
351 	}
352 
353 	if (strcmp(argv[1], "-") == 0) {
354 		fstat(STDIN_FILENO, &stb2);
355 		gotstdin = 1;
356 	} else if (stat(argv[1], &stb2) != 0) {
357 		if (!Nflag || errno != ENOENT)
358 			err(2, "%s", argv[1]);
359 		dflags |= D_EMPTY2;
360 		memset(&stb2, 0, sizeof(stb2));
361 		stb2.st_mode = stb1.st_mode;
362 	}
363 
364 	if (dflags & D_EMPTY1 && dflags & D_EMPTY2){
365 		warn("%s", argv[0]);
366 		warn("%s", argv[1]);
367 		exit(2);
368 	}
369 
370 	if (stb1.st_mode == 0)
371 		stb1.st_mode = stb2.st_mode;
372 
373 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
374 		errx(2, "can't compare - to a directory");
375 	set_argstr(oargv, argv);
376 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
377 		if (diff_format == D_IFDEF)
378 			errx(2, "-D option not supported with directories");
379 		diffdir(argv[0], argv[1], dflags);
380 	} else {
381 		if (S_ISDIR(stb1.st_mode)) {
382 			argv[0] = splice(argv[0], argv[1]);
383 			if (stat(argv[0], &stb1) == -1)
384 				err(2, "%s", argv[0]);
385 		}
386 		if (S_ISDIR(stb2.st_mode)) {
387 			argv[1] = splice(argv[1], argv[0]);
388 			if (stat(argv[1], &stb2) == -1)
389 				err(2, "%s", argv[1]);
390 		}
391 		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
392 		    argv[1], "");
393 	}
394 	exit(status);
395 }
396 
397 void
398 set_argstr(char **av, char **ave)
399 {
400 	size_t argsize;
401 	char **ap;
402 
403 	argsize = 4 + *ave - *av + 1;
404 	diffargs = xmalloc(argsize);
405 	strlcpy(diffargs, "diff", argsize);
406 	for (ap = av + 1; ap < ave; ap++) {
407 		if (strcmp(*ap, "--") != 0) {
408 			strlcat(diffargs, " ", argsize);
409 			strlcat(diffargs, *ap, argsize);
410 		}
411 	}
412 }
413 
414 /*
415  * Read in an excludes file and push each line.
416  */
417 void
418 read_excludes_file(char *file)
419 {
420 	FILE *fp;
421 	char *buf, *pattern;
422 	size_t len;
423 
424 	if (strcmp(file, "-") == 0)
425 		fp = stdin;
426 	else if ((fp = fopen(file, "r")) == NULL)
427 		err(2, "%s", file);
428 	while ((buf = fgetln(fp, &len)) != NULL) {
429 		if (buf[len - 1] == '\n')
430 			len--;
431 		if ((pattern = strndup(buf, len)) == NULL)
432 			err(2, "xstrndup");
433 		push_excludes(pattern);
434 	}
435 	if (strcmp(file, "-") != 0)
436 		fclose(fp);
437 }
438 
439 /*
440  * Push a pattern onto the excludes list.
441  */
442 void
443 push_excludes(char *pattern)
444 {
445 	struct excludes *entry;
446 
447 	entry = xmalloc(sizeof(*entry));
448 	entry->pattern = pattern;
449 	entry->next = excludes_list;
450 	excludes_list = entry;
451 }
452 
453 void
454 push_ignore_pats(char *pattern)
455 {
456 	size_t len;
457 
458 	if (ignore_pats == NULL)
459 		ignore_pats = xstrdup(pattern);
460 	else {
461 		/* old + "|" + new + NUL */
462 		len = strlen(ignore_pats) + strlen(pattern) + 2;
463 		ignore_pats = xreallocarray(ignore_pats, 1, len);
464 		strlcat(ignore_pats, "|", len);
465 		strlcat(ignore_pats, pattern, len);
466 	}
467 }
468 
469 void
470 print_only(const char *path, size_t dirlen, const char *entry)
471 {
472 	if (dirlen > 1)
473 		dirlen--;
474 	printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
475 }
476 
477 void
478 print_status(int val, char *path1, char *path2, const char *entry)
479 {
480 	if (label[0] != NULL) path1 = label[0];
481 	if (label[1] != NULL) path2 = label[1];
482 
483 	switch (val) {
484 	case D_BINARY:
485 		printf("Binary files %s%s and %s%s differ\n",
486 		    path1, entry, path2, entry);
487 		break;
488 	case D_DIFFER:
489 		if (diff_format == D_BRIEF)
490 			printf("Files %s%s and %s%s differ\n",
491 			    path1, entry, path2, entry);
492 		break;
493 	case D_SAME:
494 		if (sflag)
495 			printf("Files %s%s and %s%s are identical\n",
496 			    path1, entry, path2, entry);
497 		break;
498 	case D_MISMATCH1:
499 		printf("File %s%s is a directory while file %s%s is a regular file\n",
500 		    path1, entry, path2, entry);
501 		break;
502 	case D_MISMATCH2:
503 		printf("File %s%s is a regular file while file %s%s is a directory\n",
504 		    path1, entry, path2, entry);
505 		break;
506 	case D_SKIPPED1:
507 		printf("File %s%s is not a regular file or directory and was skipped\n",
508 		    path1, entry);
509 		break;
510 	case D_SKIPPED2:
511 		printf("File %s%s is not a regular file or directory and was skipped\n",
512 		    path2, entry);
513 		break;
514 	case D_ERROR:
515 		break;
516 	}
517 }
518 
519 void
520 usage(void)
521 {
522 	(void)fprintf(stderr,
523 	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
524 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
525 	    "            [-I pattern] [-L label] file1 file2\n"
526 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
527 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
528 	    "            -C number file1 file2\n"
529 	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
530 	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
531 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
532 	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
533 	    "            -U number file1 file2\n"
534 	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
535 	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
536 	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n"
537 	    "       diff [-aBbditwW] [--expand-tabs] [--ignore-all-blanks]\n"
538             "            [--ignore-blank-lines] [--ignore-case] [--minimal]\n"
539             "            [--no-ignore-file-name-case] [--strip-trailing-cr]\n"
540             "            [--suppress-common-lines] [--tabsize] [--text] [--width]\n"
541             "            -y | --side-by-side file1 file2\n");
542 
543 	exit(2);
544 }
545 
546 void
547 conflicting_format(void)
548 {
549 
550 	fprintf(stderr, "error: conflicting output format options.\n");
551 	usage();
552 }
553