xref: /openbsd-src/usr.bin/cmp/regular.c (revision 5054e3e78af0749a9bb00ba9a024b3ee2d90290f)
1 /*      $OpenBSD: regular.c,v 1.9 2009/10/27 23:59:36 deraadt Exp $      */
2 /*      $NetBSD: regular.c,v 1.2 1995/09/08 03:22:59 tls Exp $      */
3 
4 /*-
5  * Copyright (c) 1991, 1993, 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/param.h>
34 #include <sys/mman.h>
35 #include <sys/stat.h>
36 
37 #include <err.h>
38 #include <limits.h>
39 #include <stdlib.h>
40 #include <stdio.h>
41 #include <string.h>
42 
43 #include "extern.h"
44 
45 void
46 c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
47 	int fd1, fd2;
48 	char *file1, *file2;
49 	off_t skip1, len1, skip2, len2;
50 {
51 	u_char ch, *p1, *p2;
52 	off_t byte, length, line;
53 	int dfound;
54 
55 	if (sflag && len1 != len2)
56 		exit(1);
57 
58 	if (skip1 > len1)
59 		eofmsg(file1);
60 	len1 -= skip1;
61 	if (skip2 > len2)
62 		eofmsg(file2);
63 	len2 -= skip2;
64 
65 	length = MIN(len1, len2);
66 	if (length > SIZE_T_MAX) {
67 	mmap_failed:
68 		c_special(fd1, file1, skip1, fd2, file2, skip2);
69 		return;
70 	}
71 
72 	if ((p1 = mmap(NULL, (size_t)length, PROT_READ,
73 	    MAP_PRIVATE, fd1, skip1)) == MAP_FAILED)
74 		goto mmap_failed;
75 	if ((p2 = mmap(NULL, (size_t)length, PROT_READ,
76 	    MAP_PRIVATE, fd2, skip2)) == MAP_FAILED) {
77 		munmap(p1, (size_t)length);
78 		goto mmap_failed;
79 	}
80 	if (length) {
81 		madvise(p1, length, MADV_SEQUENTIAL);
82 		madvise(p2, length, MADV_SEQUENTIAL);
83 	}
84 
85 	dfound = 0;
86 	for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
87 		if ((ch = *p1) != *p2) {
88 			if (lflag) {
89 				dfound = 1;
90 				(void)printf("%6lld %3o %3o\n", (long long)byte,
91 				    ch, *p2);
92 			} else
93 				diffmsg(file1, file2, byte, line);
94 				/* NOTREACHED */
95 		}
96 		if (ch == '\n')
97 			++line;
98 	}
99 
100 	if (len1 != len2)
101 		eofmsg (len1 > len2 ? file2 : file1);
102 	if (dfound)
103 		exit(DIFF_EXIT);
104 }
105