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 81 siginfo(int signo) 82 { 83 info = signo; 84 } 85 #endif 86 87 static void usage(void) __dead2; 88 89 static bool 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 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 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