xref: /openbsd-src/usr.bin/diff/diff.c (revision 96e45528389e5f614e52e3b7183c18cde06a9a2e)
1 /*	$OpenBSD: diff.c,v 1.44 2004/01/07 17:18:32 otto 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 1.44 2004/01/07 17:18:32 otto Exp $";
25 #endif /* not lint */
26 
27 #include <sys/param.h>
28 #include <sys/stat.h>
29 
30 #include <ctype.h>
31 #include <err.h>
32 #include <errno.h>
33 #include <getopt.h>
34 #include <signal.h>
35 #include <stdlib.h>
36 #include <stdio.h>
37 #include <stdarg.h>
38 #include <string.h>
39 #include <unistd.h>
40 
41 #include "diff.h"
42 
43 int	 aflag, bflag, dflag, iflag, lflag, Nflag, Pflag, pflag, rflag;
44 int	 sflag, tflag, Tflag, wflag;
45 int	 format, context, status;
46 char	*start, *ifdefname, *diffargs, *label;
47 struct stat stb1, stb2;
48 struct excludes *excludes_list;
49 
50 #define	OPTIONS	"0123456789abC:cdD:efhiL:lnNPpqrS:sTtU:uwX:x:"
51 static struct option longopts[] = {
52 	{ "text",			no_argument,		0,	'a' },
53 	{ "ignore-space-change",	no_argument,		0,	'b' },
54 	{ "context",			optional_argument,	0,	'C' },
55 	{ "ifdef",			required_argument,	0,	'D' },
56 	{ "minimal",			no_argument,		0,	'd' },
57 	{ "ed",				no_argument,		0,	'e' },
58 	{ "forward-ed",			no_argument,		0,	'f' },
59 	{ "ignore-case",		no_argument,		0,	'i' },
60 	{ "paginate",			no_argument,		0,	'l' },
61 	{ "label",			required_argument,	0,	'L' },
62 	{ "new-file",			no_argument,		0,	'N' },
63 	{ "rcs",			no_argument,		0,	'n' },
64 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
65 	{ "show-c-function",		no_argument,		0,	'p' },
66 	{ "brief",			no_argument,		0,	'q' },
67 	{ "recursive",			no_argument,		0,	'r' },
68 	{ "report-identical-files",	no_argument,		0,	's' },
69 	{ "starting-file",		required_argument,	0,	'S' },
70 	{ "expand-tabs",		no_argument,		0,	't' },
71 	{ "initial-tab",		no_argument,		0,	'T' },
72 	{ "unified",			optional_argument,	0,	'U' },
73 	{ "ignore-all-space",		no_argument,		0,	'w' },
74 	{ "exclude",			required_argument,	0,	'x' },
75 	{ "exclude-from",		required_argument,	0,	'X' },
76 	{ NULL,				0,			0,	'\0'}
77 };
78 
79 __dead void usage(void);
80 void push_excludes(char *);
81 void read_excludes_file(char *file);
82 void set_argstr(char **, char **);
83 
84 int
85 main(int argc, char **argv)
86 {
87 	char *ep, **oargv;
88 	long  l;
89 	int   ch, lastch, gotstdin, prevoptind, newarg;
90 
91 	oargv = argv;
92 	gotstdin = 0;
93 
94 	lastch = '\0';
95 	prevoptind = 1;
96 	newarg = 1;
97 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
98 		switch (ch) {
99 		case '0': case '1': case '2': case '3': case '4':
100 		case '5': case '6': case '7': case '8': case '9':
101 			if (newarg)
102 				usage();	/* disallow -[0-9]+ */
103 			else if (lastch == 'c' || lastch == 'u')
104 				context = 0;
105 			else if (!isdigit(lastch) || context > INT_MAX / 10)
106 				usage();
107 			context = (context * 10) + (ch - '0');
108 			break;
109 		case 'a':
110 			aflag = 1;
111 			break;
112 		case 'b':
113 			bflag = 1;
114 			break;
115 		case 'C':
116 		case 'c':
117 			format = D_CONTEXT;
118 			if (optarg != NULL) {
119 				l = strtol(optarg, &ep, 10);
120 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
121 					usage();
122 				context = (int)l;
123 			} else
124 				context = 3;
125 			break;
126 		case 'd':
127 			dflag = 1;
128 			break;
129 		case 'D':
130 			format = D_IFDEF;
131 			ifdefname = optarg;
132 			break;
133 		case 'e':
134 			format = D_EDIT;
135 			break;
136 		case 'f':
137 			format = D_REVERSE;
138 			break;
139 		case 'h':
140 			/* silently ignore for backwards compatibility */
141 			break;
142 		case 'i':
143 			iflag = 1;
144 			break;
145 		case 'L':
146 			label = optarg;
147 			break;
148 		case 'l':
149 			lflag = 1;
150 			signal(SIGPIPE, SIG_IGN);
151 			break;
152 		case 'N':
153 			Nflag = 1;
154 			break;
155 		case 'n':
156 			format = D_NREVERSE;
157 			break;
158 		case 'p':
159 			pflag = 1;
160 			break;
161 		case 'P':
162 			Pflag = 1;
163 			break;
164 		case 'r':
165 			rflag = 1;
166 			break;
167 		case 'q':
168 			format = D_BRIEF;
169 			break;
170 		case 'S':
171 			start = optarg;
172 			break;
173 		case 's':
174 			sflag = 1;
175 			break;
176 		case 'T':
177 			Tflag = 1;
178 			break;
179 		case 't':
180 			tflag = 1;
181 			break;
182 		case 'U':
183 		case 'u':
184 			format = D_UNIFIED;
185 			if (optarg != NULL) {
186 				l = strtol(optarg, &ep, 10);
187 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
188 					usage();
189 				context = (int)l;
190 			} else
191 				context = 3;
192 			break;
193 		case 'w':
194 			wflag = 1;
195 			break;
196 		case 'X':
197 			read_excludes_file(optarg);
198 			break;
199 		case 'x':
200 			push_excludes(optarg);
201 			break;
202 		default:
203 			usage();
204 			break;
205 		}
206 		lastch = ch;
207 		newarg = optind != prevoptind;
208 		prevoptind = optind;
209 	}
210 	argc -= optind;
211 	argv += optind;
212 
213 	/*
214 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
215 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
216 	 */
217 	if (argc != 2)
218 		usage();
219 	if (strcmp(argv[0], "-") == 0) {
220 		fstat(STDIN_FILENO, &stb1);
221 		gotstdin = 1;
222 	} else if (stat(argv[0], &stb1) != 0)
223 		err(2, "%s", argv[0]);
224 	if (strcmp(argv[1], "-") == 0) {
225 		fstat(STDIN_FILENO, &stb2);
226 		gotstdin = 1;
227 	} else if (stat(argv[1], &stb2) != 0)
228 		err(2, "%s", argv[1]);
229 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
230 		errx(2, "can't compare - to a directory");
231 	set_argstr(oargv + 1, argv);
232 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
233 		if (format == D_IFDEF)
234 			errx(2, "-D option not supported with directories");
235 		diffdir(argv[0], argv[1]);
236 	} else {
237 		if (S_ISDIR(stb1.st_mode)) {
238 			argv[0] = splice(argv[0], argv[1]);
239 			if (stat(argv[0], &stb1) < 0)
240 				err(2, "%s", argv[0]);
241 		}
242 		if (S_ISDIR(stb2.st_mode)) {
243 			argv[1] = splice(argv[1], argv[0]);
244 			if (stat(argv[1], &stb2) < 0)
245 				err(2, "%s", argv[1]);
246 		}
247 		print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1],
248 		    NULL);
249 	}
250 	exit(status);
251 }
252 
253 void *
254 emalloc(size_t n)
255 {
256 	void *p;
257 
258 	if ((p = malloc(n)) == NULL)
259 		err(2, NULL);
260 	return (p);
261 }
262 
263 void *
264 erealloc(void *p, size_t n)
265 {
266 	void *q;
267 
268 	if ((q = realloc(p, n)) == NULL)
269 		err(2, NULL);
270 	return (q);
271 }
272 
273 int
274 easprintf(char **ret, const char *fmt, ...)
275 {
276 	int len;
277 	va_list ap;
278 
279 	va_start(ap, fmt);
280 	len = vasprintf(ret, fmt, ap);
281 	va_end(ap);
282 
283 	if (len == -1)
284 		err(2, NULL);
285 	return (len);
286 }
287 
288 void
289 set_argstr(char **av, char **ave)
290 {
291 	size_t argsize;
292 	char **ap;
293 
294 	argsize = 4 + *ave - *av + 1;
295 	diffargs = emalloc(argsize);
296 	strlcpy(diffargs, "diff", argsize);
297 	for (ap = av + 1; ap < ave; ap++) {
298 		if (strcmp(*ap, "--") != 0) {
299 			strlcat(diffargs, " ", argsize);
300 			strlcat(diffargs, *ap, argsize);
301 		}
302 	}
303 }
304 
305 /*
306  * Read in an excludes file and push each line.
307  */
308 void
309 read_excludes_file(char *file)
310 {
311 	FILE *fp;
312 	char *buf, *pattern;
313 	size_t len;
314 
315 	if (strcmp(file, "-") == 0)
316 		fp = stdin;
317 	else if ((fp = fopen(file, "r")) == NULL)
318 		err(2, "%s", file);
319 	while ((buf = fgetln(fp, &len)) != NULL) {
320 		if (buf[len - 1] == '\n')
321 			len--;
322 		pattern = emalloc(len + 1);
323 		memcpy(pattern, buf, len);
324 		pattern[len] = '\0';
325 		push_excludes(pattern);
326 	}
327 	if (strcmp(file, "-") != 0)
328 		fclose(fp);
329 }
330 
331 /*
332  * Push a pattern onto the excludes list.
333  */
334 void
335 push_excludes(char *pattern)
336 {
337 	struct excludes *entry;
338 
339 	entry = emalloc(sizeof(*entry));
340 	entry->pattern = pattern;
341 	entry->next = excludes_list;
342 	excludes_list = entry;
343 }
344 
345 void
346 print_only(const char *path, size_t dirlen, const char *entry)
347 {
348 	if (dirlen > 1)
349 		dirlen--;
350 	printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
351 }
352 
353 void
354 print_status(int val, char *path1, char *path2, char *entry)
355 {
356 	switch (val) {
357 	case D_ONLY:
358 		print_only(path1, strlen(path1), entry);
359 		break;
360 	case D_COMMON:
361 		printf("Common subdirectories: %s%s and %s%s\n",
362 		    path1, entry ? entry : "", path2, entry ? entry : "");
363 		break;
364 	case D_BINARY:
365 		printf("Binary files %s%s and %s%s differ\n",
366 		    path1, entry ? entry : "", path2, entry ? entry : "");
367 		break;
368 	case D_DIFFER:
369 		if (format == D_BRIEF)
370 			printf("Files %s%s and %s%s differ\n",
371 			    path1, entry ? entry : "",
372 			    path2, entry ? entry : "");
373 		break;
374 	case D_SAME:
375 		if (sflag)
376 			printf("Files %s%s and %s%s are identical\n",
377 			    path1, entry ? entry : "",
378 			    path2, entry ? entry : "");
379 		break;
380 	case D_MISMATCH1:
381 		printf("File %s%s is a directory while file %s%s is a regular file\n",
382 		    path1, entry ? entry : "", path2, entry ? entry : "");
383 		break;
384 	case D_MISMATCH2:
385 		printf("File %s%s is a regular file while file %s%s is a directory\n",
386 		    path1, entry ? entry : "", path2, entry ? entry : "");
387 		break;
388 	}
389 }
390 
391 __dead void
392 usage(void)
393 {
394 	(void)fprintf(stderr,
395 	    "usage: diff [-abdilpqtTw] [-c | -e | -f | -n | -u] [-L label] file1 file2\n"
396 	    "       diff [-abdilpqtTw] [-L label] -C number file1 file2\n"
397 	    "       diff [-abdilqtw] -D string file1 file2\n"
398 	    "       diff [-abdilpqtTw] [-L label] -U number file1 file2\n"
399 	    "       diff [-abdilNPpqtTw] [-c | -e | -f | -n | -u ] [-L label] [-r] [-s]\n"
400 	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n");
401 
402 	exit(2);
403 }
404