xref: /openbsd-src/usr.bin/diff/diff.c (revision de41415836bb14cf4a42db4b24855c7542937ddb)
1 /*	$OpenBSD: diff.c,v 1.31 2003/07/21 22:57:16 millert 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 1.31 2003/07/21 22:57:16 millert 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, iflag, lflag, Nflag, Pflag, rflag, sflag, tflag, wflag;
43 int	 format, context, status;
44 char	*start, *ifdefname, *diffargs;
45 struct stat stb1, stb2;
46 struct excludes *excludes_list;
47 
48 #define	OPTIONS	"abC:cD:efhilnNPqrS:stU:uwX:x:"
49 static struct option longopts[] = {
50 	{ "text",			no_argument,		0,	'a' },
51 	{ "ignore-space-change",	no_argument,		0,	'b' },
52 	{ "context",			optional_argument,	0,	'C' },
53 	{ "ifdef",			required_argument,	0,	'D' },
54 	{ "ed",				no_argument,		0,	'e' },
55 	{ "forward-ed",			no_argument,		0,	'f' },
56 	{ "ignore-case",		no_argument,		0,	'i' },
57 	{ "paginate",			no_argument,		0,	'l' },
58 	{ "new-file",			no_argument,		0,	'N' },
59 	{ "rcs",			no_argument,		0,	'n' },
60 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
61 	{ "brief",			no_argument,		0,	'q' },
62 	{ "recursive",			no_argument,		0,	'r' },
63 	{ "report-identical-files",	no_argument,		0,	's' },
64 	{ "starting-file",		required_argument,	0,	'S' },
65 	{ "expand-tabs",		no_argument,		0,	't' },
66 	{ "unified",			optional_argument,	0,	'U' },
67 	{ "ignore-all-space",		no_argument,		0,	'w' },
68 	{ "exclude",			required_argument,	0,	'x' },
69 	{ "exclude-from",		required_argument,	0,	'X' },
70 };
71 
72 __dead void usage(void);
73 void push_excludes(char *);
74 void read_excludes_file(char *file);
75 void set_argstr(char **, char **);
76 
77 int
78 main(int argc, char **argv)
79 {
80 	char *ep, **oargv;
81 	long  l;
82 	int   ch, gotstdin;
83 
84 	oargv = argv;
85 	gotstdin = 0;
86 
87 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
88 		switch (ch) {
89 		case 'a':
90 			aflag = 1;
91 			break;
92 		case 'b':
93 			bflag = 1;
94 			break;
95 		case 'C':
96 		case 'c':
97 			format = D_CONTEXT;
98 			if (optarg != NULL) {
99 				l = strtol(optarg, &ep, 10);
100 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
101 					usage();
102 				context = (int)l;
103 			} else
104 				context = 3;
105 			break;
106 		case 'D':
107 			format = D_IFDEF;
108 			ifdefname = optarg;
109 			break;
110 		case 'e':
111 			format = D_EDIT;
112 			break;
113 		case 'f':
114 			format = D_REVERSE;
115 			break;
116 		case 'h':
117 			/* silently ignore for backwards compatibility */
118 			break;
119 		case 'i':
120 			iflag = 1;
121 			break;
122 		case 'l':
123 			lflag = 1;
124 			signal(SIGPIPE, SIG_IGN);
125 			break;
126 		case 'N':
127 			Nflag = 1;
128 			break;
129 		case 'n':
130 			format = D_NREVERSE;
131 			break;
132 		case 'P':
133 			Pflag = 1;
134 			break;
135 		case 'r':
136 			rflag = 1;
137 			break;
138 		case 'q':
139 			format = D_BRIEF;
140 			break;
141 		case 'S':
142 			start = optarg;
143 			break;
144 		case 's':
145 			sflag = 1;
146 			break;
147 		case 't':
148 			tflag = 1;
149 			break;
150 		case 'U':
151 		case 'u':
152 			format = D_UNIFIED;
153 			if (optarg != NULL) {
154 				l = strtol(optarg, &ep, 10);
155 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
156 					usage();
157 				context = (int)l;
158 			} else
159 				context = 3;
160 			break;
161 		case 'w':
162 			wflag = 1;
163 			break;
164 		case 'X':
165 			read_excludes_file(optarg);
166 			break;
167 		case 'x':
168 			push_excludes(optarg);
169 			break;
170 		default:
171 			usage();
172 			break;
173 		}
174 	}
175 	argc -= optind;
176 	argv += optind;
177 
178 	/*
179 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
180 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
181 	 */
182 	if (argc != 2)
183 		usage();
184 	if (strcmp(argv[0], "-") == 0) {
185 		fstat(STDIN_FILENO, &stb1);
186 		gotstdin = 1;
187 	} else if (stat(argv[0], &stb1) != 0)
188 		err(2, "%s", argv[0]);
189 	if (strcmp(argv[1], "-") == 0) {
190 		fstat(STDIN_FILENO, &stb2);
191 		gotstdin = 1;
192 	} else if (stat(argv[1], &stb2) != 0)
193 		err(2, "%s", argv[1]);
194 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
195 		errx(2, "can't compare - to a directory");
196 	set_argstr(oargv, argv);
197 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
198 		if (format == D_IFDEF)
199 			errx(2, "-D option not supported with directories");
200 		diffdir(argv[0], argv[1]);
201 	} else {
202 		if (S_ISDIR(stb1.st_mode)) {
203 			argv[0] = splice(argv[0], argv[1]);
204 			if (stat(argv[0], &stb1) < 0)
205 				err(2, "%s", argv[0]);
206 		}
207 		if (S_ISDIR(stb2.st_mode)) {
208 			argv[1] = splice(argv[1], argv[0]);
209 			if (stat(argv[1], &stb2) < 0)
210 				err(2, "%s", argv[1]);
211 		}
212 		print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1],
213 		    NULL);
214 	}
215 	exit(status);
216 }
217 
218 void *
219 emalloc(size_t n)
220 {
221 	void *p;
222 
223 	if ((p = malloc(n)) == NULL)
224 		err(2, NULL);
225 	return (p);
226 }
227 
228 void *
229 erealloc(void *p, size_t n)
230 {
231 	void *q;
232 
233 	if ((q = realloc(p, n)) == NULL)
234 		err(2, NULL);
235 	return (q);
236 }
237 
238 int
239 easprintf(char **ret, const char *fmt, ...)
240 {
241 	int len;
242 	va_list ap;
243 
244 	va_start(ap, fmt);
245 	len = vasprintf(ret, fmt, ap);
246 	va_end(ap);
247 
248 	if (len == -1)
249 		err(2, NULL);
250 	return (len);
251 }
252 
253 void
254 set_argstr(char **av, char **ave)
255 {
256 	size_t argsize;
257 	char **ap;
258 
259 	argsize = 4 + (char *)ave - (char *)av + 1;
260 	diffargs = emalloc(argsize);
261 	strlcpy(diffargs, "diff", argsize);
262 	for (ap = av + 1; ap < ave; ap++) {
263 		if (strcmp(*ap, "--") != 0) {
264 			strlcat(diffargs, " ", argsize);
265 			strlcat(diffargs, *ap, argsize);
266 		}
267 	}
268 }
269 
270 /*
271  * Read in an excludes file and push each line.
272  */
273 void
274 read_excludes_file(char *file)
275 {
276 	FILE *fp;
277 	char *buf, *pattern;
278 	size_t len;
279 
280 	if (strcmp(file, "-") == 0)
281 		fp = stdin;
282 	else if ((fp = fopen(file, "r")) == NULL)
283 		err(2, "%s", file);
284 	while ((buf = fgetln(fp, &len)) != NULL) {
285 		if (buf[len - 1] == '\n')
286 			len--;
287 		pattern = emalloc(len + 1);
288 		memcpy(pattern, buf, len);
289 		pattern[len] = '\0';
290 		push_excludes(pattern);
291 	}
292 	if (strcmp(file, "-") != 0)
293 		fclose(fp);
294 }
295 
296 /*
297  * Push a pattern onto the excludes list.
298  */
299 void
300 push_excludes(char *pattern)
301 {
302 	struct excludes *entry;
303 
304 	entry = emalloc(sizeof(*entry));
305 	entry->pattern = pattern;
306 	entry->next = excludes_list;
307 	excludes_list = entry;
308 }
309 
310 void
311 print_status(int val, char *path1, char *path2, char *entry)
312 {
313 	switch (val) {
314 	case D_ONLY:
315 		printf("Only in %s: %s\n", path1, entry);
316 		break;
317 	case D_COMMON:
318 		printf("Common subdirectories: %s%s and %s%s\n",
319 		    path1, entry ? entry : "", path2, entry ? entry : "");
320 		break;
321 	case D_BINARY:
322 		printf("Binary files %s%s and %s%s differ\n",
323 		    path1, entry ? entry : "", path2, entry ? entry : "");
324 		break;
325 	case D_DIFFER:
326 		if (format == D_BRIEF)
327 			printf("Files %s%s and %s%s differ\n",
328 			    path1, entry ? entry : "",
329 			    path2, entry ? entry : "");
330 		break;
331 	case D_SAME:
332 		if (sflag)
333 			printf("Files %s%s and %s%s are identical\n",
334 			    path1, entry ? entry : "",
335 			    path2, entry ? entry : "");
336 		break;
337 	case D_MISMATCH1:
338 		printf("File %s%s is a directory while file %s%s is a regular file\n",
339 		    path1, entry ? entry : "", path2, entry ? entry : "");
340 		break;
341 	case D_MISMATCH2:
342 		printf("File %s%s is a regular file while file %s%s is a directory\n",
343 		    path1, entry ? entry : "", path2, entry ? entry : "");
344 		break;
345 	}
346 }
347 
348 __dead void
349 usage(void)
350 {
351 	(void)fprintf(stderr,
352 	    "usage: diff [-biqtw] [-c | -e | -f | -n | -u ] file1 file2\n"
353 	    "       diff [-biqtw] -C number file1 file2\n"
354 	    "       diff [-biqtw] -D string file1 file2\n"
355 	    "       diff [-biqtw] -U number file1 file2\n"
356 	    "       diff [-biNPqwt] [-c | -e | -f | -n | -u ] [-r] [-s] [-S name]"
357 	    " [-X file]\n            [-x pattern] dir1 dir2\n");
358 
359 	exit(2);
360 }
361