xref: /netbsd-src/usr.bin/cmp/regular.c (revision 5bbd2a12505d72a8177929a37b5cee489d0a1cfd)
1 /*	$NetBSD: regular.c,v 1.23 2011/11/28 10:10:10 wiz 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 1.23 2011/11/28 10:10:10 wiz 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 <stdio.h>
49 
50 #include "extern.h"
51 
52 void
53 c_regular(int fd1, const char *file1, off_t skip1, off_t len1,
54     int fd2, const char *file2, off_t skip2, off_t len2)
55 {
56 	u_char ch, *p1, *p2;
57 	off_t byte, length, line;
58 	int dfound;
59 	size_t blk_sz, blk_cnt;
60 
61 	if (sflag && len1 != len2)
62 		exit(1);
63 
64 	if (skip1 > len1)
65 		eofmsg(file1, len1 + 1, 0);
66 	len1 -= skip1;
67 	if (skip2 > len2)
68 		eofmsg(file2, len2 + 1, 0);
69 	len2 -= skip2;
70 
71 	byte = line = 1;
72 	dfound = 0;
73 	length = MIN(len1, len2);
74 	for (blk_sz = 1024 * 1024; length != 0; length -= blk_sz) {
75 		if ((uintmax_t)blk_sz > (uintmax_t)length)
76 			blk_sz = length;
77 		p1 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED,
78 		    fd1, skip1);
79 		if (p1 == MAP_FAILED)
80 			goto mmap_failed;
81 
82 		p2 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED,
83 		    fd2, skip2);
84 		if (p2 == MAP_FAILED) {
85 			munmap(p1, blk_sz);
86 			goto mmap_failed;
87 		}
88 
89 		blk_cnt = blk_sz;
90 		for (; blk_cnt--; ++p1, ++p2, ++byte) {
91 			if ((ch = *p1) != *p2) {
92 				if (!lflag) {
93 					diffmsg(file1, file2, byte, line);
94 					/* NOTREACHED */
95 				}
96 				dfound = 1;
97 				(void)printf("%6lld %3o %3o\n",
98 				    (long long)byte, ch, *p2);
99 			}
100 			if (ch == '\n')
101 				++line;
102 		}
103 		munmap(p1 - blk_sz, blk_sz);
104 		munmap(p2 - blk_sz, blk_sz);
105 		skip1 += blk_sz;
106 		skip2 += blk_sz;
107 	}
108 
109 	if (len1 != len2)
110 		eofmsg(len1 > len2 ? file2 : file1, byte, line);
111 	if (dfound)
112 		exit(DIFF_EXIT);
113 	return;
114 
115 mmap_failed:
116 	c_special(fd1, file1, skip1, fd2, file2, skip2);
117 }
118