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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $FreeBSD: src/usr.bin/cmp/regular.c,v 1.7.2.3 2001/11/21 10:47:54 dwmalone Exp $ 34 * $DragonFly: src/usr.bin/cmp/regular.c,v 1.4 2003/11/03 19:31:28 eirikn Exp $ 35 * 36 * @(#)regular.c 8.3 (Berkeley) 4/2/94 37 */ 38 39 #include <sys/param.h> 40 #include <sys/mman.h> 41 #include <sys/stat.h> 42 43 #include <err.h> 44 #include <limits.h> 45 #include <stdlib.h> 46 #include <stdio.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 #include "extern.h" 51 52 static u_char *remmap(u_char *, int, off_t); 53 #define MMAP_CHUNK (8*1024*1024) 54 55 #define ROUNDPAGE(i) ((i) & ~pagemask) 56 57 void 58 c_regular(int fd1, const char *file1, off_t skip1, off_t len1, int fd2, 59 const char *file2, off_t skip2, off_t len2) 60 { 61 u_char ch, *p1, *p2, *m1, *m2, *e1, *e2; 62 off_t byte, length, line; 63 int dfound; 64 off_t pagemask, off1, off2; 65 size_t pagesize; 66 67 if (skip1 > len1) 68 eofmsg(file1); 69 len1 -= skip1; 70 if (skip2 > len2) 71 eofmsg(file2); 72 len2 -= skip2; 73 74 if (sflag && len1 != len2) 75 exit(DIFF_EXIT); 76 77 pagesize = getpagesize(); 78 pagemask = (off_t)pagesize - 1; 79 off1 = ROUNDPAGE(skip1); 80 off2 = ROUNDPAGE(skip2); 81 82 length = MIN(len1, len2); 83 84 if ((m1 = remmap(NULL, fd1, off1)) == NULL) { 85 c_special(fd1, file1, skip1, fd2, file2, skip2); 86 return; 87 } 88 89 if ((m2 = remmap(NULL, fd2, off2)) == NULL) { 90 munmap(m1, MMAP_CHUNK); 91 c_special(fd1, file1, skip1, fd2, file2, skip2); 92 return; 93 } 94 95 dfound = 0; 96 e1 = m1 + MMAP_CHUNK; 97 e2 = m2 + MMAP_CHUNK; 98 p1 = m1 + (skip1 - off1); 99 p2 = m2 + (skip2 - off2); 100 101 for (byte = line = 1; length--; ++byte) { 102 if ((ch = *p1) != *p2) { 103 if (xflag) { 104 dfound = 1; 105 printf("%08jx %02x %02x\n", 106 (intmax_t)byte - 1, ch, *p2); 107 } else if (lflag) { 108 dfound = 1; 109 printf("%6jd %3o %3o\n", 110 (intmax_t)byte, ch, *p2); 111 } else { 112 diffmsg(file1, file2, byte, line); 113 /* NOTREACHED */ 114 } 115 } 116 if (ch == '\n') 117 ++line; 118 if (++p1 == e1) { 119 off1 += MMAP_CHUNK; 120 if ((p1 = m1 = remmap(m1, fd1, off1)) == NULL) { 121 munmap(m2, MMAP_CHUNK); 122 err(ERR_EXIT, "remmap %s", file1); 123 } 124 e1 = m1 + MMAP_CHUNK; 125 } 126 if (++p2 == e2) { 127 off2 += MMAP_CHUNK; 128 if ((p2 = m2 = remmap(m2, fd2, off2)) == NULL) { 129 munmap(m1, MMAP_CHUNK); 130 err(ERR_EXIT, "remmap %s", file2); 131 } 132 e2 = m2 + MMAP_CHUNK; 133 } 134 } 135 munmap(m1, MMAP_CHUNK); 136 munmap(m2, MMAP_CHUNK); 137 138 if (len1 != len2) 139 eofmsg (len1 > len2 ? file2 : file1); 140 if (dfound) 141 exit(DIFF_EXIT); 142 } 143 144 static u_char * 145 remmap(u_char *mem, int fd, off_t offset) 146 { 147 if (mem != NULL) 148 munmap(mem, MMAP_CHUNK); 149 mem = mmap(NULL, MMAP_CHUNK, PROT_READ, MAP_SHARED, fd, offset); 150 if (mem == MAP_FAILED) 151 return (NULL); 152 madvise(mem, MMAP_CHUNK, MADV_SEQUENTIAL); 153 return (mem); 154 } 155