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 __FBSDID("$FreeBSD$"); 46 47 #include <sys/types.h> 48 #include <sys/stat.h> 49 50 #include <capsicum_helpers.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <getopt.h> 55 #include <nl_types.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 #include "extern.h" 62 63 int lflag, sflag, xflag, zflag; 64 65 static const struct option long_opts[] = 66 { 67 {"verbose", no_argument, NULL, 'l'}, 68 {"silent", no_argument, NULL, 's'}, 69 {"quiet", no_argument, NULL, 's'}, 70 {NULL, no_argument, NULL, 0} 71 }; 72 73 static void usage(void); 74 75 int 76 main(int argc, char *argv[]) 77 { 78 struct stat sb1, sb2; 79 off_t skip1, skip2; 80 int ch, fd1, fd2, oflag, special; 81 const char *file1, *file2; 82 83 oflag = O_RDONLY; 84 while ((ch = getopt_long(argc, argv, "+hlsxz", long_opts, NULL)) != -1) 85 switch (ch) { 86 case 'h': /* Don't follow symlinks */ 87 oflag |= O_NOFOLLOW; 88 break; 89 case 'l': /* print all differences */ 90 lflag = 1; 91 break; 92 case 's': /* silent run */ 93 sflag = 1; 94 zflag = 1; 95 break; 96 case 'x': /* hex output */ 97 lflag = 1; 98 xflag = 1; 99 break; 100 case 'z': /* compare size first */ 101 zflag = 1; 102 break; 103 case '?': 104 default: 105 usage(); 106 } 107 argv += optind; 108 argc -= optind; 109 110 if (lflag && sflag) 111 errx(ERR_EXIT, "specifying -s with -l or -x is not permitted"); 112 113 if (argc < 2 || argc > 4) 114 usage(); 115 116 /* Don't limit rights on stdin since it may be one of the inputs. */ 117 if (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF)) 118 err(ERR_EXIT, "unable to limit rights on stdout"); 119 if (caph_limit_stream(STDERR_FILENO, CAPH_WRITE | CAPH_IGNORE_EBADF)) 120 err(ERR_EXIT, "unable to limit rights on stderr"); 121 122 /* Backward compatibility -- handle "-" meaning stdin. */ 123 special = 0; 124 if (strcmp(file1 = argv[0], "-") == 0) { 125 special = 1; 126 fd1 = STDIN_FILENO; 127 file1 = "stdin"; 128 } else if ((fd1 = open(file1, oflag, 0)) < 0 && errno != EMLINK) { 129 if (!sflag) 130 err(ERR_EXIT, "%s", file1); 131 else 132 exit(ERR_EXIT); 133 } 134 if (strcmp(file2 = argv[1], "-") == 0) { 135 if (special) 136 errx(ERR_EXIT, 137 "standard input may only be specified once"); 138 special = 1; 139 fd2 = STDIN_FILENO; 140 file2 = "stdin"; 141 } else if ((fd2 = open(file2, oflag, 0)) < 0 && errno != EMLINK) { 142 if (!sflag) 143 err(ERR_EXIT, "%s", file2); 144 else 145 exit(ERR_EXIT); 146 } 147 148 skip1 = argc > 2 ? strtol(argv[2], NULL, 0) : 0; 149 skip2 = argc == 4 ? strtol(argv[3], NULL, 0) : 0; 150 151 if (fd1 == -1) { 152 if (fd2 == -1) { 153 c_link(file1, skip1, file2, skip2); 154 exit(0); 155 } else if (!sflag) 156 errx(ERR_EXIT, "%s: Not a symbolic link", file2); 157 else 158 exit(ERR_EXIT); 159 } else if (fd2 == -1) { 160 if (!sflag) 161 errx(ERR_EXIT, "%s: Not a symbolic link", file1); 162 else 163 exit(ERR_EXIT); 164 } 165 166 /* FD rights are limited in c_special() and c_regular(). */ 167 caph_cache_catpages(); 168 169 if (!special) { 170 if (fstat(fd1, &sb1)) { 171 if (!sflag) 172 err(ERR_EXIT, "%s", file1); 173 else 174 exit(ERR_EXIT); 175 } 176 if (!S_ISREG(sb1.st_mode)) 177 special = 1; 178 else { 179 if (fstat(fd2, &sb2)) { 180 if (!sflag) 181 err(ERR_EXIT, "%s", file2); 182 else 183 exit(ERR_EXIT); 184 } 185 if (!S_ISREG(sb2.st_mode)) 186 special = 1; 187 } 188 } 189 190 if (special) 191 c_special(fd1, file1, skip1, fd2, file2, skip2); 192 else { 193 if (zflag && sb1.st_size != sb2.st_size) { 194 if (!sflag) 195 (void) printf("%s %s differ: size\n", 196 file1, file2); 197 exit(DIFF_EXIT); 198 } 199 c_regular(fd1, file1, skip1, sb1.st_size, 200 fd2, file2, skip2, sb2.st_size); 201 } 202 exit(0); 203 } 204 205 static void 206 usage(void) 207 { 208 209 (void)fprintf(stderr, 210 "usage: cmp [-l | -s | -x] [-hz] file1 file2 [skip1 [skip2]]\n"); 211 exit(ERR_EXIT); 212 } 213