xref: /openbsd-src/usr.bin/diff/diff.c (revision 1f9aa9e07695c5317d84ab6a2883b6664348f42c)
1 /*	$OpenBSD: diff.c,v 1.33 2003/07/22 01:16:01 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 1.33 2003/07/22 01:16:01 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, Tflag,
43 	 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:cD: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 	{ "ed",				no_argument,		0,	'e' },
56 	{ "forward-ed",			no_argument,		0,	'f' },
57 	{ "ignore-case",		no_argument,		0,	'i' },
58 	{ "paginate",			no_argument,		0,	'l' },
59 	{ "label",			required_argument,	0,	'L' },
60 	{ "new-file",			no_argument,		0,	'N' },
61 	{ "rcs",			no_argument,		0,	'n' },
62 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
63 	{ "brief",			no_argument,		0,	'q' },
64 	{ "recursive",			no_argument,		0,	'r' },
65 	{ "report-identical-files",	no_argument,		0,	's' },
66 	{ "starting-file",		required_argument,	0,	'S' },
67 	{ "expand-tabs",		no_argument,		0,	't' },
68 	{ "intial-tab",			no_argument,		0,	'T' },
69 	{ "unified",			optional_argument,	0,	'U' },
70 	{ "ignore-all-space",		no_argument,		0,	'w' },
71 	{ "exclude",			required_argument,	0,	'x' },
72 	{ "exclude-from",		required_argument,	0,	'X' },
73 };
74 
75 __dead void usage(void);
76 void push_excludes(char *);
77 void read_excludes_file(char *file);
78 void set_argstr(char **, char **);
79 
80 int
81 main(int argc, char **argv)
82 {
83 	char *ep, **oargv;
84 	long  l;
85 	int   ch, gotstdin;
86 
87 	oargv = argv;
88 	gotstdin = 0;
89 
90 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
91 		switch (ch) {
92 		case 'a':
93 			aflag = 1;
94 			break;
95 		case 'b':
96 			bflag = 1;
97 			break;
98 		case 'C':
99 		case 'c':
100 			format = D_CONTEXT;
101 			if (optarg != NULL) {
102 				l = strtol(optarg, &ep, 10);
103 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
104 					usage();
105 				context = (int)l;
106 			} else
107 				context = 3;
108 			break;
109 		case 'D':
110 			format = D_IFDEF;
111 			ifdefname = optarg;
112 			break;
113 		case 'e':
114 			format = D_EDIT;
115 			break;
116 		case 'f':
117 			format = D_REVERSE;
118 			break;
119 		case 'h':
120 			/* silently ignore for backwards compatibility */
121 			break;
122 		case 'i':
123 			iflag = 1;
124 			break;
125 		case 'L':
126 			label = optarg;
127 			break;
128 		case 'l':
129 			lflag = 1;
130 			signal(SIGPIPE, SIG_IGN);
131 			break;
132 		case 'N':
133 			Nflag = 1;
134 			break;
135 		case 'n':
136 			format = D_NREVERSE;
137 			break;
138 		case 'P':
139 			Pflag = 1;
140 			break;
141 		case 'r':
142 			rflag = 1;
143 			break;
144 		case 'q':
145 			format = D_BRIEF;
146 			break;
147 		case 'S':
148 			start = optarg;
149 			break;
150 		case 's':
151 			sflag = 1;
152 			break;
153 		case 'T':
154 			Tflag = 1;
155 			break;
156 		case 't':
157 			tflag = 1;
158 			break;
159 		case 'U':
160 		case 'u':
161 			format = D_UNIFIED;
162 			if (optarg != NULL) {
163 				l = strtol(optarg, &ep, 10);
164 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
165 					usage();
166 				context = (int)l;
167 			} else
168 				context = 3;
169 			break;
170 		case 'w':
171 			wflag = 1;
172 			break;
173 		case 'X':
174 			read_excludes_file(optarg);
175 			break;
176 		case 'x':
177 			push_excludes(optarg);
178 			break;
179 		default:
180 			usage();
181 			break;
182 		}
183 	}
184 	argc -= optind;
185 	argv += optind;
186 
187 	/*
188 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
189 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
190 	 */
191 	if (argc != 2)
192 		usage();
193 	if (strcmp(argv[0], "-") == 0) {
194 		fstat(STDIN_FILENO, &stb1);
195 		gotstdin = 1;
196 	} else if (stat(argv[0], &stb1) != 0)
197 		err(2, "%s", argv[0]);
198 	if (strcmp(argv[1], "-") == 0) {
199 		fstat(STDIN_FILENO, &stb2);
200 		gotstdin = 1;
201 	} else if (stat(argv[1], &stb2) != 0)
202 		err(2, "%s", argv[1]);
203 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
204 		errx(2, "can't compare - to a directory");
205 	set_argstr(oargv, argv);
206 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
207 		if (format == D_IFDEF)
208 			errx(2, "-D option not supported with directories");
209 		diffdir(argv[0], argv[1]);
210 	} else {
211 		if (S_ISDIR(stb1.st_mode)) {
212 			argv[0] = splice(argv[0], argv[1]);
213 			if (stat(argv[0], &stb1) < 0)
214 				err(2, "%s", argv[0]);
215 		}
216 		if (S_ISDIR(stb2.st_mode)) {
217 			argv[1] = splice(argv[1], argv[0]);
218 			if (stat(argv[1], &stb2) < 0)
219 				err(2, "%s", argv[1]);
220 		}
221 		print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1],
222 		    NULL);
223 	}
224 	exit(status);
225 }
226 
227 void *
228 emalloc(size_t n)
229 {
230 	void *p;
231 
232 	if ((p = malloc(n)) == NULL)
233 		err(2, NULL);
234 	return (p);
235 }
236 
237 void *
238 erealloc(void *p, size_t n)
239 {
240 	void *q;
241 
242 	if ((q = realloc(p, n)) == NULL)
243 		err(2, NULL);
244 	return (q);
245 }
246 
247 int
248 easprintf(char **ret, const char *fmt, ...)
249 {
250 	int len;
251 	va_list ap;
252 
253 	va_start(ap, fmt);
254 	len = vasprintf(ret, fmt, ap);
255 	va_end(ap);
256 
257 	if (len == -1)
258 		err(2, NULL);
259 	return (len);
260 }
261 
262 void
263 set_argstr(char **av, char **ave)
264 {
265 	size_t argsize;
266 	char **ap;
267 
268 	argsize = 4 + (char *)ave - (char *)av + 1;
269 	diffargs = emalloc(argsize);
270 	strlcpy(diffargs, "diff", argsize);
271 	for (ap = av + 1; ap < ave; ap++) {
272 		if (strcmp(*ap, "--") != 0) {
273 			strlcat(diffargs, " ", argsize);
274 			strlcat(diffargs, *ap, argsize);
275 		}
276 	}
277 }
278 
279 /*
280  * Read in an excludes file and push each line.
281  */
282 void
283 read_excludes_file(char *file)
284 {
285 	FILE *fp;
286 	char *buf, *pattern;
287 	size_t len;
288 
289 	if (strcmp(file, "-") == 0)
290 		fp = stdin;
291 	else if ((fp = fopen(file, "r")) == NULL)
292 		err(2, "%s", file);
293 	while ((buf = fgetln(fp, &len)) != NULL) {
294 		if (buf[len - 1] == '\n')
295 			len--;
296 		pattern = emalloc(len + 1);
297 		memcpy(pattern, buf, len);
298 		pattern[len] = '\0';
299 		push_excludes(pattern);
300 	}
301 	if (strcmp(file, "-") != 0)
302 		fclose(fp);
303 }
304 
305 /*
306  * Push a pattern onto the excludes list.
307  */
308 void
309 push_excludes(char *pattern)
310 {
311 	struct excludes *entry;
312 
313 	entry = emalloc(sizeof(*entry));
314 	entry->pattern = pattern;
315 	entry->next = excludes_list;
316 	excludes_list = entry;
317 }
318 
319 void
320 print_status(int val, char *path1, char *path2, char *entry)
321 {
322 	switch (val) {
323 	case D_ONLY:
324 		/* must strip off the trailing '/' */
325 		printf("Only in %.*s: %s\n", (int)(strlen(path1) - 1),
326 		    path1, entry);
327 		break;
328 	case D_COMMON:
329 		printf("Common subdirectories: %s%s and %s%s\n",
330 		    path1, entry ? entry : "", path2, entry ? entry : "");
331 		break;
332 	case D_BINARY:
333 		printf("Binary files %s%s and %s%s differ\n",
334 		    path1, entry ? entry : "", path2, entry ? entry : "");
335 		break;
336 	case D_DIFFER:
337 		if (format == D_BRIEF)
338 			printf("Files %s%s and %s%s differ\n",
339 			    path1, entry ? entry : "",
340 			    path2, entry ? entry : "");
341 		break;
342 	case D_SAME:
343 		if (sflag)
344 			printf("Files %s%s and %s%s are identical\n",
345 			    path1, entry ? entry : "",
346 			    path2, entry ? entry : "");
347 		break;
348 	case D_MISMATCH1:
349 		printf("File %s%s is a directory while file %s%s is a regular file\n",
350 		    path1, entry ? entry : "", path2, entry ? entry : "");
351 		break;
352 	case D_MISMATCH2:
353 		printf("File %s%s is a regular file while file %s%s is a directory\n",
354 		    path1, entry ? entry : "", path2, entry ? entry : "");
355 		break;
356 	}
357 }
358 
359 __dead void
360 usage(void)
361 {
362 	(void)fprintf(stderr,
363 	    "usage: diff [-bilqtTw] [-c | -e | -f | -n | -u] [-L label] file1 file2\n"
364 	    "       diff [-bilqtTw] [-L label] -C number file1 file2\n"
365 	    "       diff [-bilqtw] -D string file1 file2\n"
366 	    "       diff [-bilqtTw] [-L label] -U number file1 file2\n"
367 	    "       diff [-bilNPqwtT] [-c | -e | -f | -n | -u ] [-L label] [-r] [-s] [-S name]\n"
368 	    "            [-X file] [-x pattern] dir1 dir2\n");
369 
370 	exit(2);
371 }
372