1 /* $NetBSD: regular.c,v 1.26 2025/01/12 06:38:21 simonb Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 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/cdefs.h> 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)regular.c 8.3 (Berkeley) 4/2/94"; 36 #else 37 __RCSID("$NetBSD: regular.c,v 1.26 2025/01/12 06:38:21 simonb Exp $"); 38 #endif 39 #endif /* not lint */ 40 41 #include <sys/param.h> 42 #include <sys/mman.h> 43 #include <sys/stat.h> 44 45 #include <err.h> 46 #include <limits.h> 47 #include <stdlib.h> 48 #include <stdint.h> 49 #include <stdio.h> 50 #include <string.h> 51 52 #include "extern.h" 53 54 void 55 c_regular(int fd1, const char *file1, off_t skip1, off_t len1, 56 int fd2, const char *file2, off_t skip2, off_t len2) 57 { 58 u_char ch, *p1, *p2; 59 off_t byte, length, line; 60 int dfound; 61 size_t blk_sz, blk_cnt; 62 63 if (skip1 > len1) 64 eofmsg(file1, len1 + 1, 0); 65 len1 -= skip1; 66 if (skip2 > len2) 67 eofmsg(file2, len2 + 1, 0); 68 len2 -= skip2; 69 70 if (sflag && len1 != len2) 71 exit(DIFF_EXIT); 72 73 byte = line = 1; 74 dfound = 0; 75 length = MIN(len1, len2); 76 for (blk_sz = 1024 * 1024; length != 0; length -= blk_sz) { 77 if ((uintmax_t)blk_sz > (uintmax_t)length) 78 blk_sz = length; 79 p1 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED, 80 fd1, skip1); 81 if (p1 == MAP_FAILED) 82 goto mmap_failed; 83 84 p2 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED, 85 fd2, skip2); 86 if (p2 == MAP_FAILED) { 87 munmap(p1, blk_sz); 88 goto mmap_failed; 89 } 90 91 blk_cnt = blk_sz; 92 if ((lflag || sflag) && (memcmp(p1, p2, blk_sz) == 0)) { 93 /* 94 * If the two blocks are the same and we are 95 * using the -l or -s flags, we don't need to 96 * count lines. There is nothing else to do 97 * except advance the pointers for munmap() 98 * below. 99 */ 100 p1 += blk_sz; 101 p2 += blk_sz; 102 } else { 103 for (; blk_cnt--; ++p1, ++p2, ++byte) { 104 if ((ch = *p1) != *p2) { 105 if (!lflag) { 106 diffmsg(file1, file2, byte, line); 107 /* NOTREACHED */ 108 } 109 dfound = 1; 110 (void)printf("%6lld %3o %3o\n", 111 (long long)byte, ch, *p2); 112 } 113 if (ch == '\n') 114 ++line; 115 } 116 } 117 munmap(p1 - blk_sz, blk_sz); 118 munmap(p2 - blk_sz, blk_sz); 119 skip1 += blk_sz; 120 skip2 += blk_sz; 121 } 122 123 if (len1 != len2) 124 eofmsg(len1 > len2 ? file2 : file1, byte, line); 125 if (dfound) 126 exit(DIFF_EXIT); 127 return; 128 129 mmap_failed: 130 c_special(fd1, file1, skip1, fd2, file2, skip2); 131 } 132