xref: /openbsd-src/usr.bin/diff/diff.c (revision f5537e3884b66f3b1961a70b768f77fb8896863f)
1 /*	$OpenBSD: diff.c,v 1.41 2003/09/07 18:50:58 jmc 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 1.41 2003/09/07 18:50:58 jmc 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	"0123456789abC: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 	{ "initial-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, lastch, gotstdin;
88 
89 	oargv = argv;
90 	gotstdin = 0;
91 
92 	lastch = 0;
93 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
94 		switch (ch) {
95 		case '0': case '1': case '2': case '3': case '4':
96 		case '5': case '6': case '7': case '8': case '9':
97 			if (!(lastch == 'c' || lastch == 'u' ||
98 			    (lastch >= '0' && lastch <= '9')))
99 				usage();
100 			if (lastch == 'c' || lastch == 'u')
101 				context = 0;
102 			context = context * 10 + ch - '0';
103 			break;
104 		case 'a':
105 			aflag = 1;
106 			break;
107 		case 'b':
108 			bflag = 1;
109 			break;
110 		case 'C':
111 		case 'c':
112 			format = D_CONTEXT;
113 			if (optarg != NULL) {
114 				l = strtol(optarg, &ep, 10);
115 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
116 					usage();
117 				context = (int)l;
118 			} else
119 				context = 3;
120 			break;
121 		case 'd':
122 			dflag = 1;
123 			break;
124 		case 'D':
125 			format = D_IFDEF;
126 			ifdefname = optarg;
127 			break;
128 		case 'e':
129 			format = D_EDIT;
130 			break;
131 		case 'f':
132 			format = D_REVERSE;
133 			break;
134 		case 'h':
135 			/* silently ignore for backwards compatibility */
136 			break;
137 		case 'i':
138 			iflag = 1;
139 			break;
140 		case 'L':
141 			label = optarg;
142 			break;
143 		case 'l':
144 			lflag = 1;
145 			signal(SIGPIPE, SIG_IGN);
146 			break;
147 		case 'N':
148 			Nflag = 1;
149 			break;
150 		case 'n':
151 			format = D_NREVERSE;
152 			break;
153 		case 'P':
154 			Pflag = 1;
155 			break;
156 		case 'r':
157 			rflag = 1;
158 			break;
159 		case 'q':
160 			format = D_BRIEF;
161 			break;
162 		case 'S':
163 			start = optarg;
164 			break;
165 		case 's':
166 			sflag = 1;
167 			break;
168 		case 'T':
169 			Tflag = 1;
170 			break;
171 		case 't':
172 			tflag = 1;
173 			break;
174 		case 'U':
175 		case 'u':
176 			format = D_UNIFIED;
177 			if (optarg != NULL) {
178 				l = strtol(optarg, &ep, 10);
179 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
180 					usage();
181 				context = (int)l;
182 			} else
183 				context = 3;
184 			break;
185 		case 'w':
186 			wflag = 1;
187 			break;
188 		case 'X':
189 			read_excludes_file(optarg);
190 			break;
191 		case 'x':
192 			push_excludes(optarg);
193 			break;
194 		default:
195 			usage();
196 			break;
197 		}
198 		lastch = ch;
199 	}
200 	argc -= optind;
201 	argv += optind;
202 
203 	/*
204 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
205 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
206 	 */
207 	if (argc != 2)
208 		usage();
209 	if (strcmp(argv[0], "-") == 0) {
210 		fstat(STDIN_FILENO, &stb1);
211 		gotstdin = 1;
212 	} else if (stat(argv[0], &stb1) != 0)
213 		err(2, "%s", argv[0]);
214 	if (strcmp(argv[1], "-") == 0) {
215 		fstat(STDIN_FILENO, &stb2);
216 		gotstdin = 1;
217 	} else if (stat(argv[1], &stb2) != 0)
218 		err(2, "%s", argv[1]);
219 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
220 		errx(2, "can't compare - to a directory");
221 	set_argstr(oargv + 1, argv);
222 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
223 		if (format == D_IFDEF)
224 			errx(2, "-D option not supported with directories");
225 		diffdir(argv[0], argv[1]);
226 	} else {
227 		if (S_ISDIR(stb1.st_mode)) {
228 			argv[0] = splice(argv[0], argv[1]);
229 			if (stat(argv[0], &stb1) < 0)
230 				err(2, "%s", argv[0]);
231 		}
232 		if (S_ISDIR(stb2.st_mode)) {
233 			argv[1] = splice(argv[1], argv[0]);
234 			if (stat(argv[1], &stb2) < 0)
235 				err(2, "%s", argv[1]);
236 		}
237 		print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1],
238 		    NULL);
239 	}
240 	exit(status);
241 }
242 
243 void *
244 emalloc(size_t n)
245 {
246 	void *p;
247 
248 	if ((p = malloc(n)) == NULL)
249 		err(2, NULL);
250 	return (p);
251 }
252 
253 void *
254 erealloc(void *p, size_t n)
255 {
256 	void *q;
257 
258 	if ((q = realloc(p, n)) == NULL)
259 		err(2, NULL);
260 	return (q);
261 }
262 
263 int
264 easprintf(char **ret, const char *fmt, ...)
265 {
266 	int len;
267 	va_list ap;
268 
269 	va_start(ap, fmt);
270 	len = vasprintf(ret, fmt, ap);
271 	va_end(ap);
272 
273 	if (len == -1)
274 		err(2, NULL);
275 	return (len);
276 }
277 
278 void
279 set_argstr(char **av, char **ave)
280 {
281 	size_t argsize;
282 	char **ap;
283 
284 	argsize = 4 + *ave - *av + 1;
285 	diffargs = emalloc(argsize);
286 	strlcpy(diffargs, "diff", argsize);
287 	for (ap = av + 1; ap < ave; ap++) {
288 		if (strcmp(*ap, "--") != 0) {
289 			strlcat(diffargs, " ", argsize);
290 			strlcat(diffargs, *ap, argsize);
291 		}
292 	}
293 }
294 
295 /*
296  * Read in an excludes file and push each line.
297  */
298 void
299 read_excludes_file(char *file)
300 {
301 	FILE *fp;
302 	char *buf, *pattern;
303 	size_t len;
304 
305 	if (strcmp(file, "-") == 0)
306 		fp = stdin;
307 	else if ((fp = fopen(file, "r")) == NULL)
308 		err(2, "%s", file);
309 	while ((buf = fgetln(fp, &len)) != NULL) {
310 		if (buf[len - 1] == '\n')
311 			len--;
312 		pattern = emalloc(len + 1);
313 		memcpy(pattern, buf, len);
314 		pattern[len] = '\0';
315 		push_excludes(pattern);
316 	}
317 	if (strcmp(file, "-") != 0)
318 		fclose(fp);
319 }
320 
321 /*
322  * Push a pattern onto the excludes list.
323  */
324 void
325 push_excludes(char *pattern)
326 {
327 	struct excludes *entry;
328 
329 	entry = emalloc(sizeof(*entry));
330 	entry->pattern = pattern;
331 	entry->next = excludes_list;
332 	excludes_list = entry;
333 }
334 
335 void
336 print_status(int val, char *path1, char *path2, char *entry)
337 {
338 	switch (val) {
339 	case D_ONLY:
340 		/* must strip off the trailing '/' */
341 		printf("Only in %.*s: %s\n", (int)(strlen(path1) - 1),
342 		    path1, entry);
343 		break;
344 	case D_COMMON:
345 		printf("Common subdirectories: %s%s and %s%s\n",
346 		    path1, entry ? entry : "", path2, entry ? entry : "");
347 		break;
348 	case D_BINARY:
349 		printf("Binary files %s%s and %s%s differ\n",
350 		    path1, entry ? entry : "", path2, entry ? entry : "");
351 		break;
352 	case D_DIFFER:
353 		if (format == D_BRIEF)
354 			printf("Files %s%s and %s%s differ\n",
355 			    path1, entry ? entry : "",
356 			    path2, entry ? entry : "");
357 		break;
358 	case D_SAME:
359 		if (sflag)
360 			printf("Files %s%s and %s%s are identical\n",
361 			    path1, entry ? entry : "",
362 			    path2, entry ? entry : "");
363 		break;
364 	case D_MISMATCH1:
365 		printf("File %s%s is a directory while file %s%s is a regular file\n",
366 		    path1, entry ? entry : "", path2, entry ? entry : "");
367 		break;
368 	case D_MISMATCH2:
369 		printf("File %s%s is a regular file while file %s%s is a directory\n",
370 		    path1, entry ? entry : "", path2, entry ? entry : "");
371 		break;
372 	}
373 }
374 
375 __dead void
376 usage(void)
377 {
378 	(void)fprintf(stderr,
379 	    "usage: diff [-abdilqtTw] [-c | -e | -f | -n | -u] [-L label] file1 file2\n"
380 	    "       diff [-abdilqtTw] [-L label] -C number file1 file2\n"
381 	    "       diff [-abdilqtw] -D string file1 file2\n"
382 	    "       diff [-abdilqtTw] [-L label] -U number file1 file2\n"
383 	    "       diff [-abdilNPqtTw] [-c | -e | -f | -n | -u ] [-L label] [-r] [-s]\n"
384 	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n");
385 
386 	exit(2);
387 }
388