forced commit to test new log_accum.pl script
[dragonfly.git] / usr.bin / cmp / regular.c
blobafcf35cae16f98ef6d9032dc46768f431cf92a93
1 /*-
2 * Copyright (c) 1991, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
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.
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.
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 $
36 * @(#)regular.c 8.3 (Berkeley) 4/2/94
39 #include <sys/param.h>
40 #include <sys/mman.h>
41 #include <sys/stat.h>
43 #include <err.h>
44 #include <limits.h>
45 #include <stdlib.h>
46 #include <stdio.h>
47 #include <string.h>
48 #include <unistd.h>
50 #include "extern.h"
52 static u_char *remmap(u_char *, int, off_t);
53 #define MMAP_CHUNK (8*1024*1024)
55 #define ROUNDPAGE(i) ((i) & ~pagemask)
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)
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;
67 if (skip1 > len1)
68 eofmsg(file1);
69 len1 -= skip1;
70 if (skip2 > len2)
71 eofmsg(file2);
72 len2 -= skip2;
74 if (sflag && len1 != len2)
75 exit(DIFF_EXIT);
77 pagesize = getpagesize();
78 pagemask = (off_t)pagesize - 1;
79 off1 = ROUNDPAGE(skip1);
80 off2 = ROUNDPAGE(skip2);
82 length = MIN(len1, len2);
84 if ((m1 = remmap(NULL, fd1, off1)) == NULL) {
85 c_special(fd1, file1, skip1, fd2, file2, skip2);
86 return;
89 if ((m2 = remmap(NULL, fd2, off2)) == NULL) {
90 munmap(m1, MMAP_CHUNK);
91 c_special(fd1, file1, skip1, fd2, file2, skip2);
92 return;
95 dfound = 0;
96 e1 = m1 + MMAP_CHUNK;
97 e2 = m2 + MMAP_CHUNK;
98 p1 = m1 + (skip1 - off1);
99 p2 = m2 + (skip2 - off2);
101 for (byte = line = 1; length--; ++byte) {
102 if ((ch = *p1) != *p2) {
103 if (xflag) {
104 dfound = 1;
105 (void)printf("%08qx %02x %02x\n", byte - 1, ch, *p2);
106 } else if (lflag) {
107 dfound = 1;
108 (void)printf("%6qd %3o %3o\n", byte, ch, *p2);
109 } else
110 diffmsg(file1, file2, byte, line);
111 /* NOTREACHED */
113 if (ch == '\n')
114 ++line;
115 if (++p1 == e1) {
116 off1 += MMAP_CHUNK;
117 if ((p1 = m1 = remmap(m1, fd1, off1)) == NULL) {
118 munmap(m2, MMAP_CHUNK);
119 err(ERR_EXIT, "remmap %s", file1);
121 e1 = m1 + MMAP_CHUNK;
123 if (++p2 == e2) {
124 off2 += MMAP_CHUNK;
125 if ((p2 = m2 = remmap(m2, fd2, off2)) == NULL) {
126 munmap(m1, MMAP_CHUNK);
127 err(ERR_EXIT, "remmap %s", file2);
129 e2 = m2 + MMAP_CHUNK;
132 munmap(m1, MMAP_CHUNK);
133 munmap(m2, MMAP_CHUNK);
135 if (len1 != len2)
136 eofmsg (len1 > len2 ? file2 : file1);
137 if (dfound)
138 exit(DIFF_EXIT);
141 static u_char *
142 remmap(u_char *mem, int fd, off_t offset)
144 if (mem != NULL)
145 munmap(mem, MMAP_CHUNK);
146 mem = mmap(NULL, MMAP_CHUNK, PROT_READ, MAP_SHARED, fd, offset);
147 if (mem == MAP_FAILED)
148 return (NULL);
149 madvise(mem, MMAP_CHUNK, MADV_SEQUENTIAL);
150 return (mem);