xref: /netbsd-src/usr.bin/cmp/regular.c (revision fd5cb0acea84d278e04e640d37ca2398f894991f)
1 /*	$NetBSD: regular.c,v 1.14 2005/02/06 21:19:46 dsl 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 1.14 2005/02/06 21:19:46 dsl 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 #include <string.h>
50 
51 #include "extern.h"
52 
53 void
54 c_regular(int fd1, char *file1, off_t skip1, off_t len1,
55 	int fd2, char *file2, off_t skip2, off_t len2)
56 {
57 	u_char ch, *p1, *p2;
58 	off_t byte, length, line;
59 	int dfound;
60 	size_t blk_sz, blk_cnt;
61 
62 	if (sflag && len1 != len2)
63 		exit(1);
64 
65 	if (skip1 > len1)
66 		eofmsg(file1);
67 	len1 -= skip1;
68 	if (skip2 > len2)
69 		eofmsg(file2);
70 	len2 -= skip2;
71 
72 	length = MIN(len1, len2);
73 	for (blk_sz = 1024 * 1024; length != 0; length -= blk_sz) {
74 		if (blk_sz > length)
75 			blk_sz = length;
76 		p1 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED, fd1, skip1);
77 		if (p1 == MAP_FAILED)
78 			goto mmap_failed;
79 
80 		p2 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED, fd2, skip2);
81 		if (p2 == MAP_FAILED) {
82 			munmap(p1, blk_sz);
83 			goto mmap_failed;
84 		}
85 
86 		dfound = 0;
87 		blk_cnt = blk_sz;
88 		for (byte = line = 1; blk_cnt--; ++p1, ++p2, ++byte) {
89 			if ((ch = *p1) != *p2) {
90 				if (!lflag) {
91 					diffmsg(file1, file2, byte, line);
92 					/* NOTREACHED */
93 				}
94 				dfound = 1;
95 				(void)printf("%6lld %3o %3o\n", (long long)byte,
96 					    ch, *p2);
97 			}
98 			if (ch == '\n')
99 				++line;
100 		}
101 		munmap(p1 - blk_sz, blk_sz);
102 		munmap(p2 - blk_sz, blk_sz);
103 		skip1 += blk_sz;
104 		skip2 += blk_sz;
105 	}
106 
107 	if (len1 != len2)
108 		eofmsg (len1 > len2 ? file2 : file1);
109 	if (dfound)
110 		exit(DIFF_EXIT);
111 	return;
112 
113 mmap_failed:
114 	c_special(fd1, file1, skip1, fd2, file2, skip2);
115 }
116