xref: /openbsd/usr.bin/diff/diff.c (revision db3296cf)
1 /*	$OpenBSD: diff.c,v 1.37 2003/07/29 18:38:47 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 #ifndef lint
24 static const char rcsid[] = "$OpenBSD: diff.c,v 1.37 2003/07/29 18:38:47 deraadt Exp $";
25 #endif /* not lint */
26 
27 #include <sys/param.h>
28 #include <sys/stat.h>
29 
30 #include <err.h>
31 #include <errno.h>
32 #include <getopt.h>
33 #include <signal.h>
34 #include <stdlib.h>
35 #include <stdio.h>
36 #include <stdarg.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 #include "diff.h"
41 
42 int	 aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, rflag;
43 int	 sflag, tflag, Tflag, wflag;
44 int	 format, context, status;
45 char	*start, *ifdefname, *diffargs, *label;
46 struct stat stb1, stb2;
47 struct excludes *excludes_list;
48 
49 #define	OPTIONS	"abC:cdD:efhiL:lnNPqrS:sTtU:uwX:x:"
50 static struct option longopts[] = {
51 	{ "text",			no_argument,		0,	'a' },
52 	{ "ignore-space-change",	no_argument,		0,	'b' },
53 	{ "context",			optional_argument,	0,	'C' },
54 	{ "ifdef",			required_argument,	0,	'D' },
55 	{ "minimal",			no_argument,		0,	'd' },
56 	{ "ed",				no_argument,		0,	'e' },
57 	{ "forward-ed",			no_argument,		0,	'f' },
58 	{ "ignore-case",		no_argument,		0,	'i' },
59 	{ "paginate",			no_argument,		0,	'l' },
60 	{ "label",			required_argument,	0,	'L' },
61 	{ "new-file",			no_argument,		0,	'N' },
62 	{ "rcs",			no_argument,		0,	'n' },
63 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
64 	{ "brief",			no_argument,		0,	'q' },
65 	{ "recursive",			no_argument,		0,	'r' },
66 	{ "report-identical-files",	no_argument,		0,	's' },
67 	{ "starting-file",		required_argument,	0,	'S' },
68 	{ "expand-tabs",		no_argument,		0,	't' },
69 	{ "intial-tab",			no_argument,		0,	'T' },
70 	{ "unified",			optional_argument,	0,	'U' },
71 	{ "ignore-all-space",		no_argument,		0,	'w' },
72 	{ "exclude",			required_argument,	0,	'x' },
73 	{ "exclude-from",		required_argument,	0,	'X' },
74 	{ NULL,				0,			0,	'\0'}
75 };
76 
77 __dead void usage(void);
78 void push_excludes(char *);
79 void read_excludes_file(char *file);
80 void set_argstr(char **, char **);
81 
82 int
83 main(int argc, char **argv)
84 {
85 	char *ep, **oargv;
86 	long  l;
87 	int   ch, gotstdin;
88 
89 	oargv = argv;
90 	gotstdin = 0;
91 
92 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
93 		switch (ch) {
94 		case 'a':
95 			aflag = 1;
96 			break;
97 		case 'b':
98 			bflag = 1;
99 			break;
100 		case 'C':
101 		case 'c':
102 			format = D_CONTEXT;
103 			if (optarg != NULL) {
104 				l = strtol(optarg, &ep, 10);
105 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
106 					usage();
107 				context = (int)l;
108 			} else
109 				context = 3;
110 			break;
111 		case 'd':
112 			dflag = 1;
113 			break;
114 		case 'D':
115 			format = D_IFDEF;
116 			ifdefname = optarg;
117 			break;
118 		case 'e':
119 			format = D_EDIT;
120 			break;
121 		case 'f':
122 			format = D_REVERSE;
123 			break;
124 		case 'h':
125 			/* silently ignore for backwards compatibility */
126 			break;
127 		case 'i':
128 			iflag = 1;
129 			break;
130 		case 'L':
131 			label = optarg;
132 			break;
133 		case 'l':
134 			lflag = 1;
135 			signal(SIGPIPE, SIG_IGN);
136 			break;
137 		case 'N':
138 			Nflag = 1;
139 			break;
140 		case 'n':
141 			format = D_NREVERSE;
142 			break;
143 		case 'P':
144 			Pflag = 1;
145 			break;
146 		case 'r':
147 			rflag = 1;
148 			break;
149 		case 'q':
150 			format = D_BRIEF;
151 			break;
152 		case 'S':
153 			start = optarg;
154 			break;
155 		case 's':
156 			sflag = 1;
157 			break;
158 		case 'T':
159 			Tflag = 1;
160 			break;
161 		case 't':
162 			tflag = 1;
163 			break;
164 		case 'U':
165 		case 'u':
166 			format = D_UNIFIED;
167 			if (optarg != NULL) {
168 				l = strtol(optarg, &ep, 10);
169 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
170 					usage();
171 				context = (int)l;
172 			} else
173 				context = 3;
174 			break;
175 		case 'w':
176 			wflag = 1;
177 			break;
178 		case 'X':
179 			read_excludes_file(optarg);
180 			break;
181 		case 'x':
182 			push_excludes(optarg);
183 			break;
184 		default:
185 			usage();
186 			break;
187 		}
188 	}
189 	argc -= optind;
190 	argv += optind;
191 
192 	/*
193 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
194 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
195 	 */
196 	if (argc != 2)
197 		usage();
198 	if (strcmp(argv[0], "-") == 0) {
199 		fstat(STDIN_FILENO, &stb1);
200 		gotstdin = 1;
201 	} else if (stat(argv[0], &stb1) != 0)
202 		err(2, "%s", argv[0]);
203 	if (strcmp(argv[1], "-") == 0) {
204 		fstat(STDIN_FILENO, &stb2);
205 		gotstdin = 1;
206 	} else if (stat(argv[1], &stb2) != 0)
207 		err(2, "%s", argv[1]);
208 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
209 		errx(2, "can't compare - to a directory");
210 	set_argstr(oargv + 1, argv);
211 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
212 		if (format == D_IFDEF)
213 			errx(2, "-D option not supported with directories");
214 		diffdir(argv[0], argv[1]);
215 	} else {
216 		if (S_ISDIR(stb1.st_mode)) {
217 			argv[0] = splice(argv[0], argv[1]);
218 			if (stat(argv[0], &stb1) < 0)
219 				err(2, "%s", argv[0]);
220 		}
221 		if (S_ISDIR(stb2.st_mode)) {
222 			argv[1] = splice(argv[1], argv[0]);
223 			if (stat(argv[1], &stb2) < 0)
224 				err(2, "%s", argv[1]);
225 		}
226 		print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1],
227 		    NULL);
228 	}
229 	exit(status);
230 }
231 
232 void *
233 emalloc(size_t n)
234 {
235 	void *p;
236 
237 	if ((p = malloc(n)) == NULL)
238 		err(2, NULL);
239 	return (p);
240 }
241 
242 void *
243 erealloc(void *p, size_t n)
244 {
245 	void *q;
246 
247 	if ((q = realloc(p, n)) == NULL)
248 		err(2, NULL);
249 	return (q);
250 }
251 
252 int
253 easprintf(char **ret, const char *fmt, ...)
254 {
255 	int len;
256 	va_list ap;
257 
258 	va_start(ap, fmt);
259 	len = vasprintf(ret, fmt, ap);
260 	va_end(ap);
261 
262 	if (len == -1)
263 		err(2, NULL);
264 	return (len);
265 }
266 
267 void
268 set_argstr(char **av, char **ave)
269 {
270 	size_t argsize;
271 	char **ap;
272 
273 	argsize = 4 + *ave - *av + 1;
274 	diffargs = emalloc(argsize);
275 	strlcpy(diffargs, "diff", argsize);
276 	for (ap = av + 1; ap < ave; ap++) {
277 		if (strcmp(*ap, "--") != 0) {
278 			strlcat(diffargs, " ", argsize);
279 			strlcat(diffargs, *ap, argsize);
280 		}
281 	}
282 }
283 
284 /*
285  * Read in an excludes file and push each line.
286  */
287 void
288 read_excludes_file(char *file)
289 {
290 	FILE *fp;
291 	char *buf, *pattern;
292 	size_t len;
293 
294 	if (strcmp(file, "-") == 0)
295 		fp = stdin;
296 	else if ((fp = fopen(file, "r")) == NULL)
297 		err(2, "%s", file);
298 	while ((buf = fgetln(fp, &len)) != NULL) {
299 		if (buf[len - 1] == '\n')
300 			len--;
301 		pattern = emalloc(len + 1);
302 		memcpy(pattern, buf, len);
303 		pattern[len] = '\0';
304 		push_excludes(pattern);
305 	}
306 	if (strcmp(file, "-") != 0)
307 		fclose(fp);
308 }
309 
310 /*
311  * Push a pattern onto the excludes list.
312  */
313 void
314 push_excludes(char *pattern)
315 {
316 	struct excludes *entry;
317 
318 	entry = emalloc(sizeof(*entry));
319 	entry->pattern = pattern;
320 	entry->next = excludes_list;
321 	excludes_list = entry;
322 }
323 
324 void
325 print_status(int val, char *path1, char *path2, char *entry)
326 {
327 	switch (val) {
328 	case D_ONLY:
329 		/* must strip off the trailing '/' */
330 		printf("Only in %.*s: %s\n", (int)(strlen(path1) - 1),
331 		    path1, entry);
332 		break;
333 	case D_COMMON:
334 		printf("Common subdirectories: %s%s and %s%s\n",
335 		    path1, entry ? entry : "", path2, entry ? entry : "");
336 		break;
337 	case D_BINARY:
338 		printf("Binary files %s%s and %s%s differ\n",
339 		    path1, entry ? entry : "", path2, entry ? entry : "");
340 		break;
341 	case D_DIFFER:
342 		if (format == D_BRIEF)
343 			printf("Files %s%s and %s%s differ\n",
344 			    path1, entry ? entry : "",
345 			    path2, entry ? entry : "");
346 		break;
347 	case D_SAME:
348 		if (sflag)
349 			printf("Files %s%s and %s%s are identical\n",
350 			    path1, entry ? entry : "",
351 			    path2, entry ? entry : "");
352 		break;
353 	case D_MISMATCH1:
354 		printf("File %s%s is a directory while file %s%s is a regular file\n",
355 		    path1, entry ? entry : "", path2, entry ? entry : "");
356 		break;
357 	case D_MISMATCH2:
358 		printf("File %s%s is a regular file while file %s%s is a directory\n",
359 		    path1, entry ? entry : "", path2, entry ? entry : "");
360 		break;
361 	}
362 }
363 
364 __dead void
365 usage(void)
366 {
367 	(void)fprintf(stderr,
368 	    "usage: diff [-bdilqtTw] [-c | -e | -f | -n | -u] [-L label] file1 file2\n"
369 	    "       diff [-bdilqtTw] [-L label] -C number file1 file2\n"
370 	    "       diff [-bdilqtw] -D string file1 file2\n"
371 	    "       diff [-bdilqtTw] [-L label] -U number file1 file2\n"
372 	    "       diff [-bdilNPqwtT] [-c | -e | -f | -n | -u ] [-L label] [-r] [-s] [-S name]\n"
373 	    "            [-X file] [-x pattern] dir1 dir2\n");
374 
375 	exit(2);
376 }
377