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 #include <sys/types.h> 33 #include <sys/stat.h> 34 35 #include <capsicum_helpers.h> 36 #include <err.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <getopt.h> 40 #include <nl_types.h> 41 #include <stdbool.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <unistd.h> 46 47 #include <libutil.h> 48 49 #include "extern.h" 50 51 bool bflag, lflag, sflag, xflag, zflag; 52 53 static const struct option long_opts[] = 54 { 55 {"print-bytes", no_argument, NULL, 'b'}, 56 {"ignore-initial", required_argument, NULL, 'i'}, 57 {"verbose", no_argument, NULL, 'l'}, 58 {"bytes", required_argument, NULL, 'n'}, 59 {"silent", no_argument, NULL, 's'}, 60 {"quiet", no_argument, NULL, 's'}, 61 {NULL, no_argument, NULL, 0} 62 }; 63 64 #ifdef SIGINFO 65 volatile sig_atomic_t info; 66 67 static void 68 siginfo(int signo) 69 { 70 info = signo; 71 } 72 #endif 73 74 static void usage(void) __dead2; 75 76 static bool 77 parse_iskipspec(char *spec, off_t *skip1, off_t *skip2) 78 { 79 char *colon; 80 81 colon = strchr(spec, ':'); 82 if (colon != NULL) 83 *colon++ = '\0'; 84 85 if (expand_number(spec, skip1) < 0) 86 return (false); 87 88 if (colon != NULL) 89 return (expand_number(colon, skip2) == 0); 90 91 *skip2 = *skip1; 92 return (true); 93 } 94 95 int 96 main(int argc, char *argv[]) 97 { 98 struct stat sb1, sb2; 99 off_t skip1, skip2, limit; 100 int ch, fd1, fd2, oflag; 101 bool special; 102 const char *file1, *file2; 103 int ret; 104 105 limit = skip1 = skip2 = ret = 0; 106 oflag = O_RDONLY; 107 while ((ch = getopt_long(argc, argv, "+bhi:ln:sxz", long_opts, NULL)) != -1) 108 switch (ch) { 109 case 'b': /* Print bytes */ 110 bflag = true; 111 break; 112 case 'h': /* Don't follow symlinks */ 113 oflag |= O_NOFOLLOW; 114 break; 115 case 'i': 116 if (!parse_iskipspec(optarg, &skip1, &skip2)) { 117 fprintf(stderr, 118 "Invalid --ignore-initial: %s\n", 119 optarg); 120 usage(); 121 } 122 break; 123 case 'l': /* print all differences */ 124 lflag = true; 125 break; 126 case 'n': /* Limit */ 127 if (expand_number(optarg, &limit) < 0 || limit < 0) { 128 fprintf(stderr, "Invalid --bytes: %s\n", 129 optarg); 130 usage(); 131 } 132 break; 133 case 's': /* silent run */ 134 sflag = true; 135 break; 136 case 'x': /* hex output */ 137 lflag = true; 138 xflag = true; 139 break; 140 case 'z': /* compare size first */ 141 zflag = true; 142 break; 143 case '?': 144 default: 145 usage(); 146 } 147 argv += optind; 148 argc -= optind; 149 150 if (lflag && sflag) 151 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted"); 152 153 if (argc < 2 || argc > 4) 154 usage(); 155 156 /* Don't limit rights on stdin since it may be one of the inputs. */ 157 if (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF)) 158 err(ERR_EXIT, "unable to limit rights on stdout"); 159 if (caph_limit_stream(STDERR_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF)) 160 err(ERR_EXIT, "unable to limit rights on stderr"); 161 162 /* Backward compatibility -- handle "-" meaning stdin. */ 163 special = false; 164 if (strcmp(file1 = argv[0], "-") == 0) { 165 special = true; 166 fd1 = STDIN_FILENO; 167 file1 = "stdin"; 168 } else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) { 169 if (!sflag) 170 err(ERR_EXIT, "%s", file1); 171 else 172 exit(ERR_EXIT); 173 } 174 if (strcmp(file2 = argv[1], "-") == 0) { 175 if (special) 176 errx(ERR_EXIT, 177 "standard input may only be specified once"); 178 special = true; 179 fd2 = STDIN_FILENO; 180 file2 = "stdin"; 181 } else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) { 182 if (!sflag) 183 err(ERR_EXIT, "%s", file2); 184 else 185 exit(ERR_EXIT); 186 } 187 188 if (argc > 2 && expand_number(argv[2], &skip1) < 0) { 189 fprintf(stderr, "Invalid skip1: %s\n", argv[2]); 190 usage(); 191 } 192 193 if (argc == 4 && expand_number(argv[3], &skip2) < 0) { 194 fprintf(stderr, "Invalid skip2: %s\n", argv[3]); 195 usage(); 196 } 197 198 if (sflag && skip1 == 0 && skip2 == 0) 199 zflag = true; 200 201 if (fd1 == -1) { 202 if (fd2 == -1) { 203 ret = c_link(file1, skip1, file2, skip2, limit); 204 goto end; 205 } else if (!sflag) 206 errx(ERR_EXIT, "%s: Not a symbolic link", file2); 207 else 208 exit(ERR_EXIT); 209 } else if (fd2 == -1) { 210 if (!sflag) 211 errx(ERR_EXIT, "%s: Not a symbolic link", file1); 212 else 213 exit(ERR_EXIT); 214 } 215 216 /* FD rights are limited in c_special() and c_regular(). */ 217 caph_cache_catpages(); 218 219 if (!special) { 220 if (fstat(fd1, &sb1)) { 221 if (!sflag) 222 err(ERR_EXIT, "%s", file1); 223 else 224 exit(ERR_EXIT); 225 } 226 if (!S_ISREG(sb1.st_mode)) 227 special = true; 228 else { 229 if (fstat(fd2, &sb2)) { 230 if (!sflag) 231 err(ERR_EXIT, "%s", file2); 232 else 233 exit(ERR_EXIT); 234 } 235 if (!S_ISREG(sb2.st_mode)) 236 special = true; 237 } 238 } 239 240 #ifdef SIGINFO 241 (void)signal(SIGINFO, siginfo); 242 #endif 243 if (special) { 244 ret = c_special(fd1, file1, skip1, fd2, file2, skip2, limit); 245 } else { 246 if (zflag && sb1.st_size != sb2.st_size) { 247 if (!sflag) 248 (void)printf("%s %s differ: size\n", 249 file1, file2); 250 ret = DIFF_EXIT; 251 } else { 252 ret = c_regular(fd1, file1, skip1, sb1.st_size, 253 fd2, file2, skip2, sb2.st_size, limit); 254 } 255 } 256 end: 257 if (!sflag && fflush(stdout) != 0) 258 err(ERR_EXIT, "stdout"); 259 exit(ret); 260 } 261 262 static void 263 usage(void) 264 { 265 266 (void)fprintf(stderr, 267 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n"); 268 exit(ERR_EXIT); 269 } 270