1 /* $OpenBSD: cmp.c,v 1.16 2016/10/28 07:22:59 schwarze 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 43 #include "extern.h" 44 45 int lflag, sflag; 46 47 static void __dead usage(void); 48 49 int 50 main(int argc, char *argv[]) 51 { 52 struct stat sb1, sb2; 53 off_t skip1, skip2; 54 int ch, fd1, fd2, special; 55 char *file1, *file2; 56 57 if (pledge("stdio rpath", NULL) == -1) 58 err(ERR_EXIT, "pledge"); 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 default: 69 usage(); 70 } 71 72 argv += optind; 73 argc -= optind; 74 75 if (lflag && sflag) 76 errx(ERR_EXIT, "only one of -l and -s may be specified"); 77 78 if (argc < 2 || argc > 4) 79 usage(); 80 81 /* Backward compatibility -- handle "-" meaning stdin. */ 82 special = 0; 83 if (strcmp(file1 = argv[0], "-") == 0) { 84 special = 1; 85 fd1 = 0; 86 file1 = "stdin"; 87 } else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) { 88 if (sflag) 89 return ERR_EXIT; 90 else 91 err(ERR_EXIT, "%s", file1); 92 } 93 if (strcmp(file2 = argv[1], "-") == 0) { 94 if (special) { 95 if (sflag) 96 return ERR_EXIT; 97 else 98 errx(ERR_EXIT, 99 "standard input may only be specified once"); 100 } 101 special = 1; 102 fd2 = 0; 103 file2 = "stdin"; 104 } else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) { 105 if (sflag) 106 return ERR_EXIT; 107 else 108 err(ERR_EXIT, "%s", file2); 109 } 110 111 if (pledge("stdio", NULL) == -1) 112 err(ERR_EXIT, "pledge"); 113 114 skip1 = argc > 2 ? strtoll(argv[2], NULL, 0) : 0; 115 skip2 = argc == 4 ? strtoll(argv[3], NULL, 0) : 0; 116 117 if (!special) { 118 if (fstat(fd1, &sb1)) { 119 if (sflag) 120 return ERR_EXIT; 121 else 122 err(ERR_EXIT, "%s", file1); 123 } 124 if (!S_ISREG(sb1.st_mode)) 125 special = 1; 126 else { 127 if (fstat(fd2, &sb2)) { 128 if (sflag) 129 return ERR_EXIT; 130 else 131 err(ERR_EXIT, "%s", file2); 132 } 133 if (!S_ISREG(sb2.st_mode)) 134 special = 1; 135 } 136 } 137 138 if (special) 139 c_special(fd1, file1, skip1, fd2, file2, skip2); 140 else 141 c_regular(fd1, file1, skip1, sb1.st_size, 142 fd2, file2, skip2, sb2.st_size); 143 return 0; 144 } 145 146 static void __dead 147 usage(void) 148 { 149 150 (void)fprintf(stderr, 151 "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n"); 152 exit(ERR_EXIT); 153 } 154