xref: /freebsd/usr.bin/diff/diff.c (revision 732a02b4e77866604a120a275c082bb6221bd2ff)
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 push_excludes(char *);
104 void push_ignore_pats(char *);
105 void read_excludes_file(char *file);
106 void set_argstr(char **, char **);
107 
108 int
109 main(int argc, char **argv)
110 {
111 	const char *errstr = NULL;
112 	char *ep, **oargv;
113 	long  l;
114 	int   ch, dflags, lastch, gotstdin, prevoptind, newarg;
115 
116 	oargv = argv;
117 	gotstdin = 0;
118 	dflags = 0;
119 	lastch = '\0';
120 	prevoptind = 1;
121 	newarg = 1;
122 	diff_context = 3;
123 	diff_format = 0;
124 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
125 		switch (ch) {
126 		case '0': case '1': case '2': case '3': case '4':
127 		case '5': case '6': case '7': case '8': case '9':
128 			if (newarg)
129 				usage();	/* disallow -[0-9]+ */
130 			else if (lastch == 'c' || lastch == 'u')
131 				diff_context = 0;
132 			else if (!isdigit(lastch) || diff_context > INT_MAX / 10)
133 				usage();
134 			diff_context = (diff_context * 10) + (ch - '0');
135 			break;
136 		case 'a':
137 			dflags |= D_FORCEASCII;
138 			break;
139 		case 'b':
140 			dflags |= D_FOLDBLANKS;
141 			break;
142 		case 'C':
143 		case 'c':
144 			cflag = 1;
145 			diff_format = D_CONTEXT;
146 			if (optarg != NULL) {
147 				l = strtol(optarg, &ep, 10);
148 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
149 					usage();
150 				diff_context = (int)l;
151 			}
152 			break;
153 		case 'd':
154 			dflags |= D_MINIMAL;
155 			break;
156 		case 'D':
157 			diff_format = D_IFDEF;
158 			ifdefname = optarg;
159 			break;
160 		case 'e':
161 			diff_format = D_EDIT;
162 			break;
163 		case 'f':
164 			diff_format = D_REVERSE;
165 			break;
166 		case 'H':
167 			/* ignore but needed for compatibility with GNU diff */
168 			break;
169 		case 'h':
170 			/* silently ignore for backwards compatibility */
171 			break;
172 		case 'B':
173 			dflags |= D_SKIPBLANKLINES;
174 			break;
175 		case 'I':
176 			push_ignore_pats(optarg);
177 			break;
178 		case 'i':
179 			dflags |= D_IGNORECASE;
180 			break;
181 		case 'L':
182 			if (label[0] == NULL)
183 				label[0] = optarg;
184 			else if (label[1] == NULL)
185 				label[1] = optarg;
186 			else
187 				usage();
188 			break;
189 		case 'l':
190 			lflag = 1;
191 			break;
192 		case 'N':
193 			Nflag = 1;
194 			break;
195 		case 'n':
196 			diff_format = D_NREVERSE;
197 			break;
198 		case 'p':
199 			if (diff_format == 0)
200 				diff_format = D_CONTEXT;
201 			dflags |= D_PROTOTYPE;
202 			break;
203 		case 'P':
204 			Pflag = 1;
205 			break;
206 		case 'r':
207 			rflag = 1;
208 			break;
209 		case 'q':
210 			diff_format = D_BRIEF;
211 			break;
212 		case 'S':
213 			start = optarg;
214 			break;
215 		case 's':
216 			sflag = 1;
217 			break;
218 		case 'T':
219 			Tflag = 1;
220 			break;
221 		case 't':
222 			dflags |= D_EXPANDTABS;
223 			break;
224 		case 'U':
225 		case 'u':
226 			diff_format = D_UNIFIED;
227 			if (optarg != NULL) {
228 				l = strtol(optarg, &ep, 10);
229 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
230 					usage();
231 				diff_context = (int)l;
232 			}
233 			break;
234 		case 'w':
235 			dflags |= D_IGNOREBLANKS;
236 			break;
237 		case 'W':
238 			Wflag = 1;
239 			width = (int) strtonum(optarg, 1, INT_MAX, &errstr);
240 			if (errstr) {
241 				warnx("Invalid argument for width");
242 				usage();
243 			}
244 			break;
245 		case 'X':
246 			read_excludes_file(optarg);
247 			break;
248 		case 'x':
249 			push_excludes(optarg);
250 			break;
251 		case 'y':
252 			diff_format = D_SIDEBYSIDE;
253 			break;
254 		case OPT_CHANGED_GROUP_FORMAT:
255 			diff_format = D_GFORMAT;
256 			group_format = optarg;
257 			break;
258 		case OPT_HORIZON_LINES:
259 			break; /* XXX TODO for compatibility with GNU diff3 */
260 		case OPT_IGN_FN_CASE:
261 			ignore_file_case = 1;
262 			break;
263 		case OPT_NO_IGN_FN_CASE:
264 			ignore_file_case = 0;
265 			break;
266 		case OPT_NORMAL:
267 			diff_format = D_NORMAL;
268 			break;
269 		case OPT_TSIZE:
270 			tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr);
271 			if (errstr) {
272 				warnx("Invalid argument for tabsize");
273 				usage();
274 			}
275 			break;
276 		case OPT_STRIPCR:
277 			dflags |= D_STRIPCR;
278 			break;
279 		case OPT_SUPPRESS_COMMON:
280 			suppress_common = 1;
281 			break;
282 		default:
283 			usage();
284 			break;
285 		}
286 		lastch = ch;
287 		newarg = optind != prevoptind;
288 		prevoptind = optind;
289 	}
290 	argc -= optind;
291 	argv += optind;
292 
293 #ifdef __OpenBSD__
294 	if (pledge("stdio rpath tmppath", NULL) == -1)
295 		err(2, "pledge");
296 #endif
297 
298 	/*
299 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
300 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
301 	 */
302 	if (argc != 2)
303 		usage();
304 	if (ignore_pats != NULL) {
305 		char buf[BUFSIZ];
306 		int error;
307 
308 		if ((error = regcomp(&ignore_re, ignore_pats,
309 				     REG_NEWLINE | REG_EXTENDED)) != 0) {
310 			regerror(error, &ignore_re, buf, sizeof(buf));
311 			if (*ignore_pats != '\0')
312 				errx(2, "%s: %s", ignore_pats, buf);
313 			else
314 				errx(2, "%s", buf);
315 		}
316 	}
317 	if (strcmp(argv[0], "-") == 0) {
318 		fstat(STDIN_FILENO, &stb1);
319 		gotstdin = 1;
320 	} else if (stat(argv[0], &stb1) != 0)
321 		err(2, "%s", argv[0]);
322 	if (strcmp(argv[1], "-") == 0) {
323 		fstat(STDIN_FILENO, &stb2);
324 		gotstdin = 1;
325 	} else if (stat(argv[1], &stb2) != 0)
326 		err(2, "%s", argv[1]);
327 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
328 		errx(2, "can't compare - to a directory");
329 	set_argstr(oargv, argv);
330 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
331 		if (diff_format == D_IFDEF)
332 			errx(2, "-D option not supported with directories");
333 		diffdir(argv[0], argv[1], dflags);
334 	} else {
335 		if (S_ISDIR(stb1.st_mode)) {
336 			argv[0] = splice(argv[0], argv[1]);
337 			if (stat(argv[0], &stb1) == -1)
338 				err(2, "%s", argv[0]);
339 		}
340 		if (S_ISDIR(stb2.st_mode)) {
341 			argv[1] = splice(argv[1], argv[0]);
342 			if (stat(argv[1], &stb2) == -1)
343 				err(2, "%s", argv[1]);
344 		}
345 		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
346 		    argv[1], "");
347 	}
348 	exit(status);
349 }
350 
351 void
352 set_argstr(char **av, char **ave)
353 {
354 	size_t argsize;
355 	char **ap;
356 
357 	argsize = 4 + *ave - *av + 1;
358 	diffargs = xmalloc(argsize);
359 	strlcpy(diffargs, "diff", argsize);
360 	for (ap = av + 1; ap < ave; ap++) {
361 		if (strcmp(*ap, "--") != 0) {
362 			strlcat(diffargs, " ", argsize);
363 			strlcat(diffargs, *ap, argsize);
364 		}
365 	}
366 }
367 
368 /*
369  * Read in an excludes file and push each line.
370  */
371 void
372 read_excludes_file(char *file)
373 {
374 	FILE *fp;
375 	char *buf, *pattern;
376 	size_t len;
377 
378 	if (strcmp(file, "-") == 0)
379 		fp = stdin;
380 	else if ((fp = fopen(file, "r")) == NULL)
381 		err(2, "%s", file);
382 	while ((buf = fgetln(fp, &len)) != NULL) {
383 		if (buf[len - 1] == '\n')
384 			len--;
385 		if ((pattern = strndup(buf, len)) == NULL)
386 			err(2, "xstrndup");
387 		push_excludes(pattern);
388 	}
389 	if (strcmp(file, "-") != 0)
390 		fclose(fp);
391 }
392 
393 /*
394  * Push a pattern onto the excludes list.
395  */
396 void
397 push_excludes(char *pattern)
398 {
399 	struct excludes *entry;
400 
401 	entry = xmalloc(sizeof(*entry));
402 	entry->pattern = pattern;
403 	entry->next = excludes_list;
404 	excludes_list = entry;
405 }
406 
407 void
408 push_ignore_pats(char *pattern)
409 {
410 	size_t len;
411 
412 	if (ignore_pats == NULL)
413 		ignore_pats = xstrdup(pattern);
414 	else {
415 		/* old + "|" + new + NUL */
416 		len = strlen(ignore_pats) + strlen(pattern) + 2;
417 		ignore_pats = xreallocarray(ignore_pats, 1, len);
418 		strlcat(ignore_pats, "|", len);
419 		strlcat(ignore_pats, pattern, len);
420 	}
421 }
422 
423 void
424 print_only(const char *path, size_t dirlen, const char *entry)
425 {
426 	if (dirlen > 1)
427 		dirlen--;
428 	printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
429 }
430 
431 void
432 print_status(int val, char *path1, char *path2, const char *entry)
433 {
434 	switch (val) {
435 	case D_BINARY:
436 		printf("Binary files %s%s and %s%s differ\n",
437 		    path1, entry, path2, entry);
438 		break;
439 	case D_DIFFER:
440 		if (diff_format == D_BRIEF)
441 			printf("Files %s%s and %s%s differ\n",
442 			    path1, entry, path2, entry);
443 		break;
444 	case D_SAME:
445 		if (sflag)
446 			printf("Files %s%s and %s%s are identical\n",
447 			    path1, entry, path2, entry);
448 		break;
449 	case D_MISMATCH1:
450 		printf("File %s%s is a directory while file %s%s is a regular file\n",
451 		    path1, entry, path2, entry);
452 		break;
453 	case D_MISMATCH2:
454 		printf("File %s%s is a regular file while file %s%s is a directory\n",
455 		    path1, entry, path2, entry);
456 		break;
457 	case D_SKIPPED1:
458 		printf("File %s%s is not a regular file or directory and was skipped\n",
459 		    path1, entry);
460 		break;
461 	case D_SKIPPED2:
462 		printf("File %s%s is not a regular file or directory and was skipped\n",
463 		    path2, entry);
464 		break;
465 	}
466 }
467 
468 void
469 usage(void)
470 {
471 	(void)fprintf(stderr,
472 	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
473 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
474 	    "            [-I pattern] [-L label] file1 file2\n"
475 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
476 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
477 	    "            -C number file1 file2\n"
478 	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
479 	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
480 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
481 	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
482 	    "            -U number file1 file2\n"
483 	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
484 	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
485 	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n"
486 	    "       diff [-aBbditwW] [--expand-tabs] [--ignore-all-blanks]\n"
487             "            [--ignore-blank-lines] [--ignore-case] [--minimal]\n"
488             "            [--no-ignore-file-name-case] [--strip-trailing-cr]\n"
489             "            [--suppress-common-lines] [--tabsize] [--text] [--width]\n"
490             "            -y | --side-by-side file1 file2\n");
491 
492 	exit(2);
493 }
494