1/* $OpenBSD: cmp.c,v 1.19 2021/10/24 21:24:16 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 <errno.h> 38#include <fcntl.h> 39#include <limits.h> 40#include <stdio.h> 41#include <stdlib.h> 42#include <string.h> 43#include <unistd.h> 44 45#include "extern.h" 46 47int lflag, sflag; 48 49static off_t get_skip(const char *, const char *); 50static void __dead usage(void); 51 52int 53main(int argc, char *argv[]) 54{ 55 struct stat sb1, sb2; 56 off_t skip1, skip2; 57 int ch, fd1, fd2, special; 58 char *file1, *file2; 59 60 if (pledge("stdio rpath", NULL) == -1) 61 err(ERR_EXIT, "pledge"); 62 63 while ((ch = getopt(argc, argv, "ls")) != -1) 64 switch (ch) { 65 case 'l': /* print all differences */ 66 lflag = 1; 67 break; 68 case 's': /* silent run */ 69 sflag = 1; 70 break; 71 default: 72 usage(); 73 } 74 75 argv += optind; 76 argc -= optind; 77 78 if (lflag && sflag) 79 errx(ERR_EXIT, "only one of -l and -s may be specified"); 80 81 if (argc < 2 || argc > 4) 82 usage(); 83 84 /* Backward compatibility -- handle "-" meaning stdin. */ 85 special = 0; 86 if (strcmp(file1 = argv[0], "-") == 0) { 87 special = 1; 88 fd1 = 0; 89 file1 = "stdin"; 90 } else if ((fd1 = open(file1, O_RDONLY)) == -1) 91 fatal("%s", file1); 92 if (strcmp(file2 = argv[1], "-") == 0) { 93 if (special) 94 fatalx("standard input may only be specified once"); 95 special = 1; 96 fd2 = 0; 97 file2 = "stdin"; 98 } else if ((fd2 = open(file2, O_RDONLY)) == -1) 99 fatal("%s", file2); 100 101 if (pledge("stdio", NULL) == -1) 102 err(ERR_EXIT, "pledge"); 103 104 skip1 = (argc > 2) ? get_skip(argv[2], "skip1") : 0; 105 skip2 = (argc == 4) ? get_skip(argv[3], "skip2") : 0; 106 107 if (!special) { 108 if (fstat(fd1, &sb1) == -1) 109 fatal("%s", file1); 110 if (!S_ISREG(sb1.st_mode)) 111 special = 1; 112 else { 113 if (fstat(fd2, &sb2) == -1) 114 fatal("%s", file2); 115 if (!S_ISREG(sb2.st_mode)) 116 special = 1; 117 } 118 } 119 120 if (special) 121 c_special(fd1, file1, skip1, fd2, file2, skip2); 122 else 123 c_regular(fd1, file1, skip1, sb1.st_size, 124 fd2, file2, skip2, sb2.st_size); 125 return 0; 126} 127 128static off_t 129get_skip(const char *arg, const char *name) 130{ 131 off_t skip; 132 char *ep; 133 134 errno = 0; 135 skip = strtoll(arg, &ep, 0); 136 if (arg[0] == '\0' || *ep != '\0') 137 fatalx("%s is invalid: %s", name, arg); 138 if (skip < 0) 139 fatalx("%s is too small: %s", name, arg); 140 if (skip == LLONG_MAX && errno == ERANGE) 141 fatalx("%s is too large: %s", name, arg); 142 return skip; 143} 144 145static void __dead 146usage(void) 147{ 148 149 (void)fprintf(stderr, 150 "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n"); 151 exit(ERR_EXIT); 152} 153