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