xref: /freebsd/usr.bin/diff/diff.c (revision 1bb4b6a76af6d04fe9d64ddad72fab84c0c84687)
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 <getopt.h>
31 #include <stdlib.h>
32 #include <stdio.h>
33 #include <string.h>
34 #include <unistd.h>
35 #include <limits.h>
36 
37 #include "diff.h"
38 #include "xmalloc.h"
39 
40 int	 lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag, Wflag;
41 int	 diff_format, diff_context, status, ignore_file_case, suppress_common;
42 int	 tabsize = 8, width = 130;
43 char	*start, *ifdefname, *diffargs, *label[2], *ignore_pats;
44 char	*group_format = NULL;
45 struct stat stb1, stb2;
46 struct excludes *excludes_list;
47 regex_t	 ignore_re;
48 
49 #define	OPTIONS	"0123456789aBbC:cdD:efHhI:iL:lnNPpqrS:sTtU:uwW:X:x:y"
50 enum {
51 	OPT_TSIZE = CHAR_MAX + 1,
52 	OPT_STRIPCR,
53 	OPT_IGN_FN_CASE,
54 	OPT_NO_IGN_FN_CASE,
55 	OPT_NORMAL,
56 	OPT_HORIZON_LINES,
57 	OPT_CHANGED_GROUP_FORMAT,
58 	OPT_SUPPRESS_COMMON,
59 };
60 
61 static struct option longopts[] = {
62 	{ "text",			no_argument,		0,	'a' },
63 	{ "ignore-space-change",	no_argument,		0,	'b' },
64 	{ "context",			optional_argument,	0,	'C' },
65 	{ "ifdef",			required_argument,	0,	'D' },
66 	{ "minimal",			no_argument,		0,	'd' },
67 	{ "ed",				no_argument,		0,	'e' },
68 	{ "forward-ed",			no_argument,		0,	'f' },
69 	{ "speed-large-files",		no_argument,		NULL,	'H' },
70 	{ "ignore-blank-lines",		no_argument,		0,	'B' },
71 	{ "ignore-matching-lines",	required_argument,	0,	'I' },
72 	{ "ignore-case",		no_argument,		0,	'i' },
73 	{ "paginate",			no_argument,		NULL,	'l' },
74 	{ "label",			required_argument,	0,	'L' },
75 	{ "new-file",			no_argument,		0,	'N' },
76 	{ "rcs",			no_argument,		0,	'n' },
77 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
78 	{ "show-c-function",		no_argument,		0,	'p' },
79 	{ "brief",			no_argument,		0,	'q' },
80 	{ "recursive",			no_argument,		0,	'r' },
81 	{ "report-identical-files",	no_argument,		0,	's' },
82 	{ "starting-file",		required_argument,	0,	'S' },
83 	{ "expand-tabs",		no_argument,		0,	't' },
84 	{ "initial-tab",		no_argument,		0,	'T' },
85 	{ "unified",			optional_argument,	0,	'U' },
86 	{ "ignore-all-space",		no_argument,		0,	'w' },
87 	{ "width",			required_argument,	0,	'W' },
88 	{ "exclude",			required_argument,	0,	'x' },
89 	{ "exclude-from",		required_argument,	0,	'X' },
90 	{ "side-by-side",		no_argument,		NULL,	'y' },
91 	{ "ignore-file-name-case",	no_argument,		NULL,	OPT_IGN_FN_CASE },
92 	{ "horizon-lines",		required_argument,	NULL,	OPT_HORIZON_LINES },
93 	{ "no-ignore-file-name-case",	no_argument,		NULL,	OPT_NO_IGN_FN_CASE },
94 	{ "normal",			no_argument,		NULL,	OPT_NORMAL },
95 	{ "strip-trailing-cr",		no_argument,		NULL,	OPT_STRIPCR },
96 	{ "tabsize",			required_argument,	NULL,	OPT_TSIZE },
97 	{ "changed-group-format",	required_argument,	NULL,	OPT_CHANGED_GROUP_FORMAT},
98 	{ "suppress-common-lines",	no_argument,		NULL,	OPT_SUPPRESS_COMMON },
99 	{ NULL,				0,			0,	'\0'}
100 };
101 
102 void usage(void) __dead2;
103 void conflicting_format(void) __dead2;
104 void push_excludes(char *);
105 void push_ignore_pats(char *);
106 void read_excludes_file(char *file);
107 void set_argstr(char **, char **);
108 
109 int
110 main(int argc, char **argv)
111 {
112 	const char *errstr = NULL;
113 	char *ep, **oargv;
114 	long  l;
115 	int   ch, dflags, lastch, gotstdin, prevoptind, newarg;
116 
117 	oargv = argv;
118 	gotstdin = 0;
119 	dflags = 0;
120 	lastch = '\0';
121 	prevoptind = 1;
122 	newarg = 1;
123 	diff_context = 3;
124 	diff_format = D_UNSET;
125 #define	FORMAT_MISMATCHED(type)	\
126 	(diff_format != D_UNSET && diff_format != (type))
127 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
128 		switch (ch) {
129 		case '0': case '1': case '2': case '3': case '4':
130 		case '5': case '6': case '7': case '8': case '9':
131 			if (newarg)
132 				usage();	/* disallow -[0-9]+ */
133 			else if (lastch == 'c' || lastch == 'u')
134 				diff_context = 0;
135 			else if (!isdigit(lastch) || diff_context > INT_MAX / 10)
136 				usage();
137 			diff_context = (diff_context * 10) + (ch - '0');
138 			break;
139 		case 'a':
140 			dflags |= D_FORCEASCII;
141 			break;
142 		case 'b':
143 			dflags |= D_FOLDBLANKS;
144 			break;
145 		case 'C':
146 		case 'c':
147 			if (FORMAT_MISMATCHED(D_CONTEXT))
148 				conflicting_format();
149 			cflag = 1;
150 			diff_format = D_CONTEXT;
151 			if (optarg != NULL) {
152 				l = strtol(optarg, &ep, 10);
153 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
154 					usage();
155 				diff_context = (int)l;
156 			}
157 			break;
158 		case 'd':
159 			dflags |= D_MINIMAL;
160 			break;
161 		case 'D':
162 			if (FORMAT_MISMATCHED(D_IFDEF))
163 				conflicting_format();
164 			diff_format = D_IFDEF;
165 			ifdefname = optarg;
166 			break;
167 		case 'e':
168 			if (FORMAT_MISMATCHED(D_EDIT))
169 				conflicting_format();
170 			diff_format = D_EDIT;
171 			break;
172 		case 'f':
173 			if (FORMAT_MISMATCHED(D_REVERSE))
174 				conflicting_format();
175 			diff_format = D_REVERSE;
176 			break;
177 		case 'H':
178 			/* ignore but needed for compatibility with GNU diff */
179 			break;
180 		case 'h':
181 			/* silently ignore for backwards compatibility */
182 			break;
183 		case 'B':
184 			dflags |= D_SKIPBLANKLINES;
185 			break;
186 		case 'I':
187 			push_ignore_pats(optarg);
188 			break;
189 		case 'i':
190 			dflags |= D_IGNORECASE;
191 			break;
192 		case 'L':
193 			if (label[0] == NULL)
194 				label[0] = optarg;
195 			else if (label[1] == NULL)
196 				label[1] = optarg;
197 			else
198 				usage();
199 			break;
200 		case 'l':
201 			lflag = 1;
202 			break;
203 		case 'N':
204 			Nflag = 1;
205 			break;
206 		case 'n':
207 			if (FORMAT_MISMATCHED(D_NREVERSE))
208 				conflicting_format();
209 			diff_format = D_NREVERSE;
210 			break;
211 		case 'p':
212 			/*
213 			 * If it's not unset and it's not set to context or
214 			 * unified, we'll error out here as a conflicting
215 			 * format.  If it's unset, we'll go ahead and set it to
216 			 * context.
217 			 */
218 			if (FORMAT_MISMATCHED(D_CONTEXT) &&
219 			    FORMAT_MISMATCHED(D_UNIFIED))
220 				conflicting_format();
221 			if (diff_format == D_UNSET)
222 				diff_format = D_CONTEXT;
223 			dflags |= D_PROTOTYPE;
224 			break;
225 		case 'P':
226 			Pflag = 1;
227 			break;
228 		case 'r':
229 			rflag = 1;
230 			break;
231 		case 'q':
232 			if (FORMAT_MISMATCHED(D_BRIEF))
233 				conflicting_format();
234 			diff_format = D_BRIEF;
235 			break;
236 		case 'S':
237 			start = optarg;
238 			break;
239 		case 's':
240 			sflag = 1;
241 			break;
242 		case 'T':
243 			Tflag = 1;
244 			break;
245 		case 't':
246 			dflags |= D_EXPANDTABS;
247 			break;
248 		case 'U':
249 		case 'u':
250 			if (FORMAT_MISMATCHED(D_UNIFIED))
251 				conflicting_format();
252 			diff_format = D_UNIFIED;
253 			if (optarg != NULL) {
254 				l = strtol(optarg, &ep, 10);
255 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
256 					usage();
257 				diff_context = (int)l;
258 			}
259 			break;
260 		case 'w':
261 			dflags |= D_IGNOREBLANKS;
262 			break;
263 		case 'W':
264 			Wflag = 1;
265 			width = (int) strtonum(optarg, 1, INT_MAX, &errstr);
266 			if (errstr) {
267 				warnx("Invalid argument for width");
268 				usage();
269 			}
270 			break;
271 		case 'X':
272 			read_excludes_file(optarg);
273 			break;
274 		case 'x':
275 			push_excludes(optarg);
276 			break;
277 		case 'y':
278 			if (FORMAT_MISMATCHED(D_SIDEBYSIDE))
279 				conflicting_format();
280 			diff_format = D_SIDEBYSIDE;
281 			break;
282 		case OPT_CHANGED_GROUP_FORMAT:
283 			if (FORMAT_MISMATCHED(D_GFORMAT))
284 				conflicting_format();
285 			diff_format = D_GFORMAT;
286 			group_format = optarg;
287 			break;
288 		case OPT_HORIZON_LINES:
289 			break; /* XXX TODO for compatibility with GNU diff3 */
290 		case OPT_IGN_FN_CASE:
291 			ignore_file_case = 1;
292 			break;
293 		case OPT_NO_IGN_FN_CASE:
294 			ignore_file_case = 0;
295 			break;
296 		case OPT_NORMAL:
297 			if (FORMAT_MISMATCHED(D_NORMAL))
298 				conflicting_format();
299 			diff_format = D_NORMAL;
300 			break;
301 		case OPT_TSIZE:
302 			tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr);
303 			if (errstr) {
304 				warnx("Invalid argument for tabsize");
305 				usage();
306 			}
307 			break;
308 		case OPT_STRIPCR:
309 			dflags |= D_STRIPCR;
310 			break;
311 		case OPT_SUPPRESS_COMMON:
312 			suppress_common = 1;
313 			break;
314 		default:
315 			usage();
316 			break;
317 		}
318 		lastch = ch;
319 		newarg = optind != prevoptind;
320 		prevoptind = optind;
321 	}
322 	if (diff_format == D_UNSET)
323 		diff_format = D_NORMAL;
324 	argc -= optind;
325 	argv += optind;
326 
327 #ifdef __OpenBSD__
328 	if (pledge("stdio rpath tmppath", NULL) == -1)
329 		err(2, "pledge");
330 #endif
331 
332 	/*
333 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
334 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
335 	 */
336 	if (argc != 2)
337 		usage();
338 	if (ignore_pats != NULL) {
339 		char buf[BUFSIZ];
340 		int error;
341 
342 		if ((error = regcomp(&ignore_re, ignore_pats,
343 				     REG_NEWLINE | REG_EXTENDED)) != 0) {
344 			regerror(error, &ignore_re, buf, sizeof(buf));
345 			if (*ignore_pats != '\0')
346 				errx(2, "%s: %s", ignore_pats, buf);
347 			else
348 				errx(2, "%s", buf);
349 		}
350 	}
351 	if (strcmp(argv[0], "-") == 0) {
352 		fstat(STDIN_FILENO, &stb1);
353 		gotstdin = 1;
354 	} else if (stat(argv[0], &stb1) != 0)
355 		err(2, "%s", argv[0]);
356 	if (strcmp(argv[1], "-") == 0) {
357 		fstat(STDIN_FILENO, &stb2);
358 		gotstdin = 1;
359 	} else if (stat(argv[1], &stb2) != 0)
360 		err(2, "%s", argv[1]);
361 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
362 		errx(2, "can't compare - to a directory");
363 	set_argstr(oargv, argv);
364 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
365 		if (diff_format == D_IFDEF)
366 			errx(2, "-D option not supported with directories");
367 		diffdir(argv[0], argv[1], dflags);
368 	} else {
369 		if (S_ISDIR(stb1.st_mode)) {
370 			argv[0] = splice(argv[0], argv[1]);
371 			if (stat(argv[0], &stb1) == -1)
372 				err(2, "%s", argv[0]);
373 		}
374 		if (S_ISDIR(stb2.st_mode)) {
375 			argv[1] = splice(argv[1], argv[0]);
376 			if (stat(argv[1], &stb2) == -1)
377 				err(2, "%s", argv[1]);
378 		}
379 		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
380 		    argv[1], "");
381 	}
382 	exit(status);
383 }
384 
385 void
386 set_argstr(char **av, char **ave)
387 {
388 	size_t argsize;
389 	char **ap;
390 
391 	argsize = 4 + *ave - *av + 1;
392 	diffargs = xmalloc(argsize);
393 	strlcpy(diffargs, "diff", argsize);
394 	for (ap = av + 1; ap < ave; ap++) {
395 		if (strcmp(*ap, "--") != 0) {
396 			strlcat(diffargs, " ", argsize);
397 			strlcat(diffargs, *ap, argsize);
398 		}
399 	}
400 }
401 
402 /*
403  * Read in an excludes file and push each line.
404  */
405 void
406 read_excludes_file(char *file)
407 {
408 	FILE *fp;
409 	char *buf, *pattern;
410 	size_t len;
411 
412 	if (strcmp(file, "-") == 0)
413 		fp = stdin;
414 	else if ((fp = fopen(file, "r")) == NULL)
415 		err(2, "%s", file);
416 	while ((buf = fgetln(fp, &len)) != NULL) {
417 		if (buf[len - 1] == '\n')
418 			len--;
419 		if ((pattern = strndup(buf, len)) == NULL)
420 			err(2, "xstrndup");
421 		push_excludes(pattern);
422 	}
423 	if (strcmp(file, "-") != 0)
424 		fclose(fp);
425 }
426 
427 /*
428  * Push a pattern onto the excludes list.
429  */
430 void
431 push_excludes(char *pattern)
432 {
433 	struct excludes *entry;
434 
435 	entry = xmalloc(sizeof(*entry));
436 	entry->pattern = pattern;
437 	entry->next = excludes_list;
438 	excludes_list = entry;
439 }
440 
441 void
442 push_ignore_pats(char *pattern)
443 {
444 	size_t len;
445 
446 	if (ignore_pats == NULL)
447 		ignore_pats = xstrdup(pattern);
448 	else {
449 		/* old + "|" + new + NUL */
450 		len = strlen(ignore_pats) + strlen(pattern) + 2;
451 		ignore_pats = xreallocarray(ignore_pats, 1, len);
452 		strlcat(ignore_pats, "|", len);
453 		strlcat(ignore_pats, pattern, len);
454 	}
455 }
456 
457 void
458 print_only(const char *path, size_t dirlen, const char *entry)
459 {
460 	if (dirlen > 1)
461 		dirlen--;
462 	printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
463 }
464 
465 void
466 print_status(int val, char *path1, char *path2, const char *entry)
467 {
468 	switch (val) {
469 	case D_BINARY:
470 		printf("Binary files %s%s and %s%s differ\n",
471 		    path1, entry, path2, entry);
472 		break;
473 	case D_DIFFER:
474 		if (diff_format == D_BRIEF)
475 			printf("Files %s%s and %s%s differ\n",
476 			    path1, entry, path2, entry);
477 		break;
478 	case D_SAME:
479 		if (sflag)
480 			printf("Files %s%s and %s%s are identical\n",
481 			    path1, entry, path2, entry);
482 		break;
483 	case D_MISMATCH1:
484 		printf("File %s%s is a directory while file %s%s is a regular file\n",
485 		    path1, entry, path2, entry);
486 		break;
487 	case D_MISMATCH2:
488 		printf("File %s%s is a regular file while file %s%s is a directory\n",
489 		    path1, entry, path2, entry);
490 		break;
491 	case D_SKIPPED1:
492 		printf("File %s%s is not a regular file or directory and was skipped\n",
493 		    path1, entry);
494 		break;
495 	case D_SKIPPED2:
496 		printf("File %s%s is not a regular file or directory and was skipped\n",
497 		    path2, entry);
498 		break;
499 	}
500 }
501 
502 void
503 usage(void)
504 {
505 	(void)fprintf(stderr,
506 	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
507 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
508 	    "            [-I pattern] [-L label] file1 file2\n"
509 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
510 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
511 	    "            -C number file1 file2\n"
512 	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
513 	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
514 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
515 	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
516 	    "            -U number file1 file2\n"
517 	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
518 	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
519 	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n"
520 	    "       diff [-aBbditwW] [--expand-tabs] [--ignore-all-blanks]\n"
521             "            [--ignore-blank-lines] [--ignore-case] [--minimal]\n"
522             "            [--no-ignore-file-name-case] [--strip-trailing-cr]\n"
523             "            [--suppress-common-lines] [--tabsize] [--text] [--width]\n"
524             "            -y | --side-by-side file1 file2\n");
525 
526 	exit(2);
527 }
528 
529 void
530 conflicting_format(void)
531 {
532 
533 	fprintf(stderr, "error: conflicting output format options.\n");
534 	usage();
535 }
536