1 /*- 2 * Copyright (c) 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: src/usr.bin/cmp/regular.c,v 1.7.2.3 2001/11/21 10:47:54 dwmalone Exp $ 30 * $DragonFly: src/usr.bin/cmp/regular.c,v 1.4 2003/11/03 19:31:28 eirikn Exp $ 31 * 32 * @(#)regular.c 8.3 (Berkeley) 4/2/94 33 */ 34 35 #include <sys/param.h> 36 #include <sys/mman.h> 37 #include <sys/stat.h> 38 39 #include <err.h> 40 #include <limits.h> 41 #include <stdlib.h> 42 #include <stdio.h> 43 #include <string.h> 44 #include <unistd.h> 45 46 #include "extern.h" 47 48 static u_char *remmap(u_char *, int, off_t); 49 #define MMAP_CHUNK (8*1024*1024) 50 51 #define ROUNDPAGE(i) ((i) & ~pagemask) 52 53 void 54 c_regular(int fd1, const char *file1, off_t skip1, off_t len1, int fd2, 55 const char *file2, off_t skip2, off_t len2) 56 { 57 u_char ch, *p1, *p2, *m1, *m2, *e1, *e2; 58 off_t byte, length, line; 59 int dfound; 60 off_t pagemask, off1, off2; 61 size_t pagesize; 62 63 if (skip1 > len1) 64 eofmsg(file1); 65 len1 -= skip1; 66 if (skip2 > len2) 67 eofmsg(file2); 68 len2 -= skip2; 69 70 if (sflag && len1 != len2) 71 exit(DIFF_EXIT); 72 73 pagesize = getpagesize(); 74 pagemask = (off_t)pagesize - 1; 75 off1 = ROUNDPAGE(skip1); 76 off2 = ROUNDPAGE(skip2); 77 78 length = MIN(len1, len2); 79 80 if ((m1 = remmap(NULL, fd1, off1)) == NULL) { 81 c_special(fd1, file1, skip1, fd2, file2, skip2); 82 return; 83 } 84 85 if ((m2 = remmap(NULL, fd2, off2)) == NULL) { 86 munmap(m1, MMAP_CHUNK); 87 c_special(fd1, file1, skip1, fd2, file2, skip2); 88 return; 89 } 90 91 dfound = 0; 92 e1 = m1 + MMAP_CHUNK; 93 e2 = m2 + MMAP_CHUNK; 94 p1 = m1 + (skip1 - off1); 95 p2 = m2 + (skip2 - off2); 96 97 for (byte = line = 1; length--; ++byte) { 98 if ((ch = *p1) != *p2) { 99 if (xflag) { 100 dfound = 1; 101 printf("%08jx %02x %02x\n", 102 (intmax_t)byte - 1, ch, *p2); 103 } else if (lflag) { 104 dfound = 1; 105 printf("%6jd %3o %3o\n", 106 (intmax_t)byte, ch, *p2); 107 } else { 108 diffmsg(file1, file2, byte, line); 109 /* NOTREACHED */ 110 } 111 } 112 if (ch == '\n') 113 ++line; 114 if (++p1 == e1) { 115 off1 += MMAP_CHUNK; 116 if ((p1 = m1 = remmap(m1, fd1, off1)) == NULL) { 117 munmap(m2, MMAP_CHUNK); 118 err(ERR_EXIT, "remmap %s", file1); 119 } 120 e1 = m1 + MMAP_CHUNK; 121 } 122 if (++p2 == e2) { 123 off2 += MMAP_CHUNK; 124 if ((p2 = m2 = remmap(m2, fd2, off2)) == NULL) { 125 munmap(m1, MMAP_CHUNK); 126 err(ERR_EXIT, "remmap %s", file2); 127 } 128 e2 = m2 + MMAP_CHUNK; 129 } 130 } 131 munmap(m1, MMAP_CHUNK); 132 munmap(m2, MMAP_CHUNK); 133 134 if (len1 != len2) 135 eofmsg (len1 > len2 ? file2 : file1); 136 if (dfound) 137 exit(DIFF_EXIT); 138 } 139 140 static u_char * 141 remmap(u_char *mem, int fd, off_t offset) 142 { 143 if (mem != NULL) 144 munmap(mem, MMAP_CHUNK); 145 mem = mmap(NULL, MMAP_CHUNK, PROT_READ, MAP_SHARED, fd, offset); 146 if (mem == MAP_FAILED) 147 return (NULL); 148 madvise(mem, MMAP_CHUNK, MADV_SEQUENTIAL); 149 return (mem); 150 } 151