1 /* $OpenBSD: cmp.c,v 1.12 2009/10/27 23:59:36 deraadt Exp $ */ 2 /* $NetBSD: cmp.c,v 1.7 1995/09/08 03:22:56 tls Exp $ */ 3 4 /* 5 * Copyright (c) 1987, 1990, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/types.h> 34 #include <sys/stat.h> 35 36 #include <err.h> 37 #include <fcntl.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 #include <locale.h> 43 44 #include "extern.h" 45 46 int lflag, sflag; 47 48 static void usage(void); 49 50 int 51 main(int argc, char *argv[]) 52 { 53 struct stat sb1, sb2; 54 off_t skip1, skip2; 55 int ch, fd1, fd2, special; 56 char *file1, *file2; 57 58 setlocale(LC_ALL, ""); 59 60 while ((ch = getopt(argc, argv, "ls")) != -1) 61 switch (ch) { 62 case 'l': /* print all differences */ 63 lflag = 1; 64 break; 65 case 's': /* silent run */ 66 sflag = 1; 67 break; 68 case '?': 69 default: 70 usage(); 71 } 72 73 argv += optind; 74 argc -= optind; 75 76 if (lflag && sflag) 77 errx(ERR_EXIT, "only one of -l and -s may be specified"); 78 79 if (argc < 2 || argc > 4) 80 usage(); 81 82 /* Backward compatibility -- handle "-" meaning stdin. */ 83 special = 0; 84 if (strcmp(file1 = argv[0], "-") == 0) { 85 special = 1; 86 fd1 = 0; 87 file1 = "stdin"; 88 } else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) { 89 if (sflag) 90 exit(ERR_EXIT); 91 else 92 err(ERR_EXIT, "%s", file1); 93 } 94 if (strcmp(file2 = argv[1], "-") == 0) { 95 if (special) { 96 if (sflag) 97 exit(ERR_EXIT); 98 else 99 errx(ERR_EXIT, 100 "standard input may only be specified once"); 101 } 102 special = 1; 103 fd2 = 0; 104 file2 = "stdin"; 105 } else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) { 106 if (sflag) 107 exit(ERR_EXIT); 108 else 109 err(ERR_EXIT, "%s", file2); 110 } 111 112 skip1 = argc > 2 ? strtoq(argv[2], NULL, 0) : 0; 113 skip2 = argc == 4 ? strtoq(argv[3], NULL, 0) : 0; 114 115 if (!special) { 116 if (fstat(fd1, &sb1)) { 117 if (sflag) 118 exit(ERR_EXIT); 119 else 120 err(ERR_EXIT, "%s", file1); 121 } 122 if (!S_ISREG(sb1.st_mode)) 123 special = 1; 124 else { 125 if (fstat(fd2, &sb2)) { 126 if (sflag) 127 exit(ERR_EXIT); 128 else 129 err(ERR_EXIT, "%s", file2); 130 } 131 if (!S_ISREG(sb2.st_mode)) 132 special = 1; 133 } 134 } 135 136 if (special) 137 c_special(fd1, file1, skip1, fd2, file2, skip2); 138 else 139 c_regular(fd1, file1, skip1, sb1.st_size, 140 fd2, file2, skip2, sb2.st_size); 141 return 0; 142 } 143 144 static void 145 usage(void) 146 { 147 148 (void)fprintf(stderr, 149 "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n"); 150 exit(ERR_EXIT); 151 } 152