xref: /freebsd/usr.bin/diff/diff.c (revision b5541f456d641d23e0c46874daff0b62552bf3cb)
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 bool	 lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag;
42 bool	 ignore_file_case, suppress_common;
43 int	 diff_format, diff_context, status;
44 int	 tabsize = 8, width = 130;
45 char	*start, *ifdefname, *diffargs, *label[2], *ignore_pats;
46 char	*group_format = NULL;
47 struct stat stb1, stb2;
48 struct excludes *excludes_list;
49 regex_t	 ignore_re;
50 
51 #define	OPTIONS	"0123456789aBbC:cdD:efHhI:iL:lnNPpqrS:sTtU:uwW:X:x:y"
52 enum {
53 	OPT_TSIZE = CHAR_MAX + 1,
54 	OPT_STRIPCR,
55 	OPT_IGN_FN_CASE,
56 	OPT_NO_IGN_FN_CASE,
57 	OPT_NORMAL,
58 	OPT_HORIZON_LINES,
59 	OPT_CHANGED_GROUP_FORMAT,
60 	OPT_SUPPRESS_COMMON,
61 };
62 
63 static struct option longopts[] = {
64 	{ "text",			no_argument,		0,	'a' },
65 	{ "ignore-space-change",	no_argument,		0,	'b' },
66 	{ "context",			optional_argument,	0,	'C' },
67 	{ "ifdef",			required_argument,	0,	'D' },
68 	{ "minimal",			no_argument,		0,	'd' },
69 	{ "ed",				no_argument,		0,	'e' },
70 	{ "forward-ed",			no_argument,		0,	'f' },
71 	{ "speed-large-files",		no_argument,		NULL,	'H' },
72 	{ "ignore-blank-lines",		no_argument,		0,	'B' },
73 	{ "ignore-matching-lines",	required_argument,	0,	'I' },
74 	{ "ignore-case",		no_argument,		0,	'i' },
75 	{ "paginate",			no_argument,		NULL,	'l' },
76 	{ "label",			required_argument,	0,	'L' },
77 	{ "new-file",			no_argument,		0,	'N' },
78 	{ "rcs",			no_argument,		0,	'n' },
79 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
80 	{ "show-c-function",		no_argument,		0,	'p' },
81 	{ "brief",			no_argument,		0,	'q' },
82 	{ "recursive",			no_argument,		0,	'r' },
83 	{ "report-identical-files",	no_argument,		0,	's' },
84 	{ "starting-file",		required_argument,	0,	'S' },
85 	{ "expand-tabs",		no_argument,		0,	't' },
86 	{ "initial-tab",		no_argument,		0,	'T' },
87 	{ "unified",			optional_argument,	0,	'U' },
88 	{ "ignore-all-space",		no_argument,		0,	'w' },
89 	{ "width",			required_argument,	0,	'W' },
90 	{ "exclude",			required_argument,	0,	'x' },
91 	{ "exclude-from",		required_argument,	0,	'X' },
92 	{ "side-by-side",		no_argument,		NULL,	'y' },
93 	{ "ignore-file-name-case",	no_argument,		NULL,	OPT_IGN_FN_CASE },
94 	{ "horizon-lines",		required_argument,	NULL,	OPT_HORIZON_LINES },
95 	{ "no-ignore-file-name-case",	no_argument,		NULL,	OPT_NO_IGN_FN_CASE },
96 	{ "normal",			no_argument,		NULL,	OPT_NORMAL },
97 	{ "strip-trailing-cr",		no_argument,		NULL,	OPT_STRIPCR },
98 	{ "tabsize",			required_argument,	NULL,	OPT_TSIZE },
99 	{ "changed-group-format",	required_argument,	NULL,	OPT_CHANGED_GROUP_FORMAT},
100 	{ "suppress-common-lines",	no_argument,		NULL,	OPT_SUPPRESS_COMMON },
101 	{ NULL,				0,			0,	'\0'}
102 };
103 
104 void usage(void) __dead2;
105 void conflicting_format(void) __dead2;
106 void push_excludes(char *);
107 void push_ignore_pats(char *);
108 void read_excludes_file(char *file);
109 void set_argstr(char **, char **);
110 
111 int
112 main(int argc, char **argv)
113 {
114 	const char *errstr = NULL;
115 	char *ep, **oargv;
116 	long  l;
117 	int   ch, dflags, lastch, gotstdin, prevoptind, newarg;
118 
119 	oargv = argv;
120 	gotstdin = 0;
121 	dflags = 0;
122 	lastch = '\0';
123 	prevoptind = 1;
124 	newarg = 1;
125 	diff_context = 3;
126 	diff_format = D_UNSET;
127 #define	FORMAT_MISMATCHED(type)	\
128 	(diff_format != D_UNSET && diff_format != (type))
129 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
130 		switch (ch) {
131 		case '0': case '1': case '2': case '3': case '4':
132 		case '5': case '6': case '7': case '8': case '9':
133 			if (newarg)
134 				usage();	/* disallow -[0-9]+ */
135 			else if (lastch == 'c' || lastch == 'u')
136 				diff_context = 0;
137 			else if (!isdigit(lastch) || diff_context > INT_MAX / 10)
138 				usage();
139 			diff_context = (diff_context * 10) + (ch - '0');
140 			break;
141 		case 'a':
142 			dflags |= D_FORCEASCII;
143 			break;
144 		case 'b':
145 			dflags |= D_FOLDBLANKS;
146 			break;
147 		case 'C':
148 		case 'c':
149 			if (FORMAT_MISMATCHED(D_CONTEXT))
150 				conflicting_format();
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 = true;
203 			break;
204 		case 'N':
205 			Nflag = true;
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 = true;
217 			break;
218 		case 'r':
219 			rflag = true;
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 = true;
231 			break;
232 		case 'T':
233 			Tflag = true;
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 			width = (int) strtonum(optarg, 1, INT_MAX, &errstr);
255 			if (errstr) {
256 				warnx("Invalid argument for width");
257 				usage();
258 			}
259 			break;
260 		case 'X':
261 			read_excludes_file(optarg);
262 			break;
263 		case 'x':
264 			push_excludes(optarg);
265 			break;
266 		case 'y':
267 			if (FORMAT_MISMATCHED(D_SIDEBYSIDE))
268 				conflicting_format();
269 			diff_format = D_SIDEBYSIDE;
270 			break;
271 		case OPT_CHANGED_GROUP_FORMAT:
272 			if (FORMAT_MISMATCHED(D_GFORMAT))
273 				conflicting_format();
274 			diff_format = D_GFORMAT;
275 			group_format = optarg;
276 			break;
277 		case OPT_HORIZON_LINES:
278 			break; /* XXX TODO for compatibility with GNU diff3 */
279 		case OPT_IGN_FN_CASE:
280 			ignore_file_case = true;
281 			break;
282 		case OPT_NO_IGN_FN_CASE:
283 			ignore_file_case = false;
284 			break;
285 		case OPT_NORMAL:
286 			if (FORMAT_MISMATCHED(D_NORMAL))
287 				conflicting_format();
288 			diff_format = D_NORMAL;
289 			break;
290 		case OPT_TSIZE:
291 			tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr);
292 			if (errstr) {
293 				warnx("Invalid argument for tabsize");
294 				usage();
295 			}
296 			break;
297 		case OPT_STRIPCR:
298 			dflags |= D_STRIPCR;
299 			break;
300 		case OPT_SUPPRESS_COMMON:
301 			suppress_common = 1;
302 			break;
303 		default:
304 			usage();
305 			break;
306 		}
307 		lastch = ch;
308 		newarg = optind != prevoptind;
309 		prevoptind = optind;
310 	}
311 	if (diff_format == D_UNSET && (dflags & D_PROTOTYPE) != 0)
312 		diff_format = D_CONTEXT;
313 	if (diff_format == D_UNSET)
314 		diff_format = D_NORMAL;
315 	argc -= optind;
316 	argv += optind;
317 
318 #ifdef __OpenBSD__
319 	if (pledge("stdio rpath tmppath", NULL) == -1)
320 		err(2, "pledge");
321 #endif
322 
323 	/*
324 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
325 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
326 	 */
327 	if (argc != 2)
328 		usage();
329 	if (ignore_pats != NULL) {
330 		char buf[BUFSIZ];
331 		int error;
332 
333 		if ((error = regcomp(&ignore_re, ignore_pats,
334 				     REG_NEWLINE | REG_EXTENDED)) != 0) {
335 			regerror(error, &ignore_re, buf, sizeof(buf));
336 			if (*ignore_pats != '\0')
337 				errx(2, "%s: %s", ignore_pats, buf);
338 			else
339 				errx(2, "%s", buf);
340 		}
341 	}
342 	if (strcmp(argv[0], "-") == 0) {
343 		fstat(STDIN_FILENO, &stb1);
344 		gotstdin = 1;
345 	} else if (stat(argv[0], &stb1) != 0) {
346 		if (!Nflag || errno != ENOENT)
347 			err(2, "%s", argv[0]);
348 		dflags |= D_EMPTY1;
349 		memset(&stb1, 0, sizeof(struct stat));
350 	}
351 
352 	if (strcmp(argv[1], "-") == 0) {
353 		fstat(STDIN_FILENO, &stb2);
354 		gotstdin = 1;
355 	} else if (stat(argv[1], &stb2) != 0) {
356 		if (!Nflag || errno != ENOENT)
357 			err(2, "%s", argv[1]);
358 		dflags |= D_EMPTY2;
359 		memset(&stb2, 0, sizeof(stb2));
360 		stb2.st_mode = stb1.st_mode;
361 	}
362 
363 	if (dflags & D_EMPTY1 && dflags & D_EMPTY2){
364 		warn("%s", argv[0]);
365 		warn("%s", argv[1]);
366 		exit(2);
367 	}
368 
369 	if (stb1.st_mode == 0)
370 		stb1.st_mode = stb2.st_mode;
371 
372 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
373 		errx(2, "can't compare - to a directory");
374 	set_argstr(oargv, argv);
375 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
376 		if (diff_format == D_IFDEF)
377 			errx(2, "-D option not supported with directories");
378 		diffdir(argv[0], argv[1], dflags);
379 	} else {
380 		if (S_ISDIR(stb1.st_mode)) {
381 			argv[0] = splice(argv[0], argv[1]);
382 			if (stat(argv[0], &stb1) == -1)
383 				err(2, "%s", argv[0]);
384 		}
385 		if (S_ISDIR(stb2.st_mode)) {
386 			argv[1] = splice(argv[1], argv[0]);
387 			if (stat(argv[1], &stb2) == -1)
388 				err(2, "%s", argv[1]);
389 		}
390 		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
391 		    argv[1], "");
392 	}
393 	exit(status);
394 }
395 
396 void
397 set_argstr(char **av, char **ave)
398 {
399 	size_t argsize;
400 	char **ap;
401 
402 	argsize = 4 + *ave - *av + 1;
403 	diffargs = xmalloc(argsize);
404 	strlcpy(diffargs, "diff", argsize);
405 	for (ap = av + 1; ap < ave; ap++) {
406 		if (strcmp(*ap, "--") != 0) {
407 			strlcat(diffargs, " ", argsize);
408 			strlcat(diffargs, *ap, argsize);
409 		}
410 	}
411 }
412 
413 /*
414  * Read in an excludes file and push each line.
415  */
416 void
417 read_excludes_file(char *file)
418 {
419 	FILE *fp;
420 	char *buf, *pattern;
421 	size_t len;
422 
423 	if (strcmp(file, "-") == 0)
424 		fp = stdin;
425 	else if ((fp = fopen(file, "r")) == NULL)
426 		err(2, "%s", file);
427 	while ((buf = fgetln(fp, &len)) != NULL) {
428 		if (buf[len - 1] == '\n')
429 			len--;
430 		if ((pattern = strndup(buf, len)) == NULL)
431 			err(2, "xstrndup");
432 		push_excludes(pattern);
433 	}
434 	if (strcmp(file, "-") != 0)
435 		fclose(fp);
436 }
437 
438 /*
439  * Push a pattern onto the excludes list.
440  */
441 void
442 push_excludes(char *pattern)
443 {
444 	struct excludes *entry;
445 
446 	entry = xmalloc(sizeof(*entry));
447 	entry->pattern = pattern;
448 	entry->next = excludes_list;
449 	excludes_list = entry;
450 }
451 
452 void
453 push_ignore_pats(char *pattern)
454 {
455 	size_t len;
456 
457 	if (ignore_pats == NULL)
458 		ignore_pats = xstrdup(pattern);
459 	else {
460 		/* old + "|" + new + NUL */
461 		len = strlen(ignore_pats) + strlen(pattern) + 2;
462 		ignore_pats = xreallocarray(ignore_pats, 1, len);
463 		strlcat(ignore_pats, "|", len);
464 		strlcat(ignore_pats, pattern, len);
465 	}
466 }
467 
468 void
469 print_only(const char *path, size_t dirlen, const char *entry)
470 {
471 	if (dirlen > 1)
472 		dirlen--;
473 	printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
474 }
475 
476 void
477 print_status(int val, char *path1, char *path2, const char *entry)
478 {
479 	if (label[0] != NULL)
480 		path1 = label[0];
481 	if (label[1] != NULL)
482 		path2 = label[1];
483 
484 	switch (val) {
485 	case D_BINARY:
486 		printf("Binary files %s%s and %s%s differ\n",
487 		    path1, entry, path2, entry);
488 		break;
489 	case D_DIFFER:
490 		if (diff_format == D_BRIEF)
491 			printf("Files %s%s and %s%s differ\n",
492 			    path1, entry, path2, entry);
493 		break;
494 	case D_SAME:
495 		if (sflag)
496 			printf("Files %s%s and %s%s are identical\n",
497 			    path1, entry, path2, entry);
498 		break;
499 	case D_MISMATCH1:
500 		printf("File %s%s is a directory while file %s%s is a regular file\n",
501 		    path1, entry, path2, entry);
502 		break;
503 	case D_MISMATCH2:
504 		printf("File %s%s is a regular file while file %s%s is a directory\n",
505 		    path1, entry, path2, entry);
506 		break;
507 	case D_SKIPPED1:
508 		printf("File %s%s is not a regular file or directory and was skipped\n",
509 		    path1, entry);
510 		break;
511 	case D_SKIPPED2:
512 		printf("File %s%s is not a regular file or directory and was skipped\n",
513 		    path2, entry);
514 		break;
515 	case D_ERROR:
516 		break;
517 	}
518 }
519 
520 void
521 usage(void)
522 {
523 	(void)fprintf(stderr,
524 	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
525 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
526 	    "            [-I pattern] [-L label] file1 file2\n"
527 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
528 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
529 	    "            -C number file1 file2\n"
530 	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
531 	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
532 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
533 	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
534 	    "            -U number file1 file2\n"
535 	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
536 	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
537 	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n"
538 	    "       diff [-aBbditwW] [--expand-tabs] [--ignore-all-blanks]\n"
539 	    "            [--ignore-blank-lines] [--ignore-case] [--minimal]\n"
540 	    "            [--no-ignore-file-name-case] [--strip-trailing-cr]\n"
541 	    "            [--suppress-common-lines] [--tabsize] [--text] [--width]\n"
542 	    "            -y | --side-by-side file1 file2\n");
543 
544 	exit(2);
545 }
546 
547 void
548 conflicting_format(void)
549 {
550 
551 	fprintf(stderr, "error: conflicting output format options.\n");
552 	usage();
553 }
554