1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1987, 1990, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1987, 1990, 1993, 1994\n\
35 The Regents of the University of California. All rights reserved.\n";
36 #endif
37
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)cmp.c 8.3 (Berkeley) 4/2/94";
41 #endif
42 #endif
43
44 #include <sys/cdefs.h>
45 #include <sys/types.h>
46 #include <sys/stat.h>
47
48 #include <capsicum_helpers.h>
49 #include <err.h>
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <getopt.h>
53 #include <nl_types.h>
54 #include <stdbool.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59
60 #include <libutil.h>
61
62 #include "extern.h"
63
64 bool bflag, lflag, sflag, xflag, zflag;
65
66 static const struct option long_opts[] =
67 {
68 {"print-bytes", no_argument, NULL, 'b'},
69 {"ignore-initial", required_argument, NULL, 'i'},
70 {"verbose", no_argument, NULL, 'l'},
71 {"bytes", required_argument, NULL, 'n'},
72 {"silent", no_argument, NULL, 's'},
73 {"quiet", no_argument, NULL, 's'},
74 {NULL, no_argument, NULL, 0}
75 };
76
77 #ifdef SIGINFO
78 volatile sig_atomic_t info;
79
80 static void
siginfo(int signo)81 siginfo(int signo)
82 {
83 info = signo;
84 }
85 #endif
86
87 static void usage(void) __dead2;
88
89 static bool
parse_iskipspec(char * spec,off_t * skip1,off_t * skip2)90 parse_iskipspec(char *spec, off_t *skip1, off_t *skip2)
91 {
92 char *colon;
93
94 colon = strchr(spec, ':');
95 if (colon != NULL)
96 *colon++ = '\0';
97
98 if (expand_number(spec, skip1) < 0)
99 return (false);
100
101 if (colon != NULL)
102 return (expand_number(colon, skip2) == 0);
103
104 *skip2 = *skip1;
105 return (true);
106 }
107
108 int
main(int argc,char * argv[])109 main(int argc, char *argv[])
110 {
111 struct stat sb1, sb2;
112 off_t skip1, skip2, limit;
113 int ch, fd1, fd2, oflag;
114 bool special;
115 const char *file1, *file2;
116 int ret;
117
118 limit = skip1 = skip2 = ret = 0;
119 oflag = O_RDONLY;
120 while ((ch = getopt_long(argc, argv, "+bhi:ln:sxz", long_opts, NULL)) != -1)
121 switch (ch) {
122 case 'b': /* Print bytes */
123 bflag = true;
124 break;
125 case 'h': /* Don't follow symlinks */
126 oflag |= O_NOFOLLOW;
127 break;
128 case 'i':
129 if (!parse_iskipspec(optarg, &skip1, &skip2)) {
130 fprintf(stderr,
131 "Invalid --ignore-initial: %s\n",
132 optarg);
133 usage();
134 }
135 break;
136 case 'l': /* print all differences */
137 lflag = true;
138 break;
139 case 'n': /* Limit */
140 if (expand_number(optarg, &limit) < 0 || limit < 0) {
141 fprintf(stderr, "Invalid --bytes: %s\n",
142 optarg);
143 usage();
144 }
145 break;
146 case 's': /* silent run */
147 sflag = true;
148 break;
149 case 'x': /* hex output */
150 lflag = true;
151 xflag = true;
152 break;
153 case 'z': /* compare size first */
154 zflag = true;
155 break;
156 case '?':
157 default:
158 usage();
159 }
160 argv += optind;
161 argc -= optind;
162
163 if (lflag && sflag)
164 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted");
165
166 if (argc < 2 || argc > 4)
167 usage();
168
169 /* Don't limit rights on stdin since it may be one of the inputs. */
170 if (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF))
171 err(ERR_EXIT, "unable to limit rights on stdout");
172 if (caph_limit_stream(STDERR_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF))
173 err(ERR_EXIT, "unable to limit rights on stderr");
174
175 /* Backward compatibility -- handle "-" meaning stdin. */
176 special = false;
177 if (strcmp(file1 = argv[0], "-") == 0) {
178 special = true;
179 fd1 = STDIN_FILENO;
180 file1 = "stdin";
181 } else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) {
182 if (!sflag)
183 err(ERR_EXIT, "%s", file1);
184 else
185 exit(ERR_EXIT);
186 }
187 if (strcmp(file2 = argv[1], "-") == 0) {
188 if (special)
189 errx(ERR_EXIT,
190 "standard input may only be specified once");
191 special = true;
192 fd2 = STDIN_FILENO;
193 file2 = "stdin";
194 } else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) {
195 if (!sflag)
196 err(ERR_EXIT, "%s", file2);
197 else
198 exit(ERR_EXIT);
199 }
200
201 if (argc > 2 && expand_number(argv[2], &skip1) < 0) {
202 fprintf(stderr, "Invalid skip1: %s\n", argv[2]);
203 usage();
204 }
205
206 if (argc == 4 && expand_number(argv[3], &skip2) < 0) {
207 fprintf(stderr, "Invalid skip2: %s\n", argv[3]);
208 usage();
209 }
210
211 if (sflag && skip1 == 0 && skip2 == 0)
212 zflag = true;
213
214 if (fd1 == -1) {
215 if (fd2 == -1) {
216 ret = c_link(file1, skip1, file2, skip2, limit);
217 goto end;
218 } else if (!sflag)
219 errx(ERR_EXIT, "%s: Not a symbolic link", file2);
220 else
221 exit(ERR_EXIT);
222 } else if (fd2 == -1) {
223 if (!sflag)
224 errx(ERR_EXIT, "%s: Not a symbolic link", file1);
225 else
226 exit(ERR_EXIT);
227 }
228
229 /* FD rights are limited in c_special() and c_regular(). */
230 caph_cache_catpages();
231
232 if (!special) {
233 if (fstat(fd1, &sb1)) {
234 if (!sflag)
235 err(ERR_EXIT, "%s", file1);
236 else
237 exit(ERR_EXIT);
238 }
239 if (!S_ISREG(sb1.st_mode))
240 special = true;
241 else {
242 if (fstat(fd2, &sb2)) {
243 if (!sflag)
244 err(ERR_EXIT, "%s", file2);
245 else
246 exit(ERR_EXIT);
247 }
248 if (!S_ISREG(sb2.st_mode))
249 special = true;
250 }
251 }
252
253 #ifdef SIGINFO
254 (void)signal(SIGINFO, siginfo);
255 #endif
256 if (special) {
257 ret = c_special(fd1, file1, skip1, fd2, file2, skip2, limit);
258 } else {
259 if (zflag && sb1.st_size != sb2.st_size) {
260 if (!sflag)
261 (void)printf("%s %s differ: size\n",
262 file1, file2);
263 ret = DIFF_EXIT;
264 } else {
265 ret = c_regular(fd1, file1, skip1, sb1.st_size,
266 fd2, file2, skip2, sb2.st_size, limit);
267 }
268 }
269 end:
270 if (!sflag && fflush(stdout) != 0)
271 err(ERR_EXIT, "stdout");
272 exit(ret);
273 }
274
275 static void
usage(void)276 usage(void)
277 {
278
279 (void)fprintf(stderr,
280 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n");
281 exit(ERR_EXIT);
282 }
283