xref: /netbsd-src/usr.bin/cmp/regular.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: regular.c,v 1.12 2003/08/07 11:13:23 agc 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 1.12 2003/08/07 11:13:23 agc 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(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
55 	int fd1, fd2;
56 	char *file1, *file2;
57 	off_t skip1, len1, skip2, len2;
58 {
59 	u_char ch, *p1, *p2;
60 	off_t byte, length, line;
61 	int dfound;
62 
63 	if (sflag && len1 != len2)
64 		exit(1);
65 
66 	if (skip1 > len1)
67 		eofmsg(file1);
68 	len1 -= skip1;
69 	if (skip2 > len2)
70 		eofmsg(file2);
71 	len2 -= skip2;
72 
73 	length = MIN(len1, len2);
74 	if (length > SIZE_T_MAX) {
75 mmap_failed:
76 		c_special(fd1, file1, skip1, fd2, file2, skip2);
77 		return;
78 	}
79 
80 	if ((p1 = (u_char *)mmap(NULL, (size_t)length,
81 	    PROT_READ, MAP_FILE|MAP_SHARED, fd1, skip1)) == MAP_FAILED)
82 		goto mmap_failed;
83 	(void)madvise(p1, (size_t)length, MADV_SEQUENTIAL);
84 
85 	if ((p2 = (u_char *)mmap(NULL, (size_t)length,
86 	    PROT_READ, MAP_FILE|MAP_SHARED, fd2, skip2)) == MAP_FAILED) {
87 		munmap(p1, (size_t) length);
88 		goto mmap_failed;
89 	}
90 	(void)madvise(p2, (size_t)length, MADV_SEQUENTIAL);
91 
92 	dfound = 0;
93 	for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
94 		if ((ch = *p1) != *p2) {
95 			if (lflag) {
96 				dfound = 1;
97 				(void)printf("%6lld %3o %3o\n", (long long)byte,
98 				    ch, *p2);
99 			} else
100 				diffmsg(file1, file2, byte, line);
101 				/* NOTREACHED */
102 		}
103 		if (ch == '\n')
104 			++line;
105 	}
106 
107 	if (len1 != len2)
108 		eofmsg (len1 > len2 ? file2 : file1);
109 	if (dfound)
110 		exit(DIFF_EXIT);
111 }
112