xref: /openbsd-src/usr.bin/cmp/regular.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*      $OpenBSD: regular.c,v 1.10 2011/01/19 13:01:25 okan 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(int fd1, char *file1, off_t skip1, off_t len1,
47     int fd2, char *file2, off_t skip2, off_t len2)
48 {
49 	u_char ch, *p1, *p2;
50 	off_t byte, length, line;
51 	int dfound;
52 
53 	if (sflag && len1 != len2)
54 		exit(1);
55 
56 	if (skip1 > len1)
57 		eofmsg(file1);
58 	len1 -= skip1;
59 	if (skip2 > len2)
60 		eofmsg(file2);
61 	len2 -= skip2;
62 
63 	length = MIN(len1, len2);
64 	if (length > SIZE_T_MAX) {
65 	mmap_failed:
66 		c_special(fd1, file1, skip1, fd2, file2, skip2);
67 		return;
68 	}
69 
70 	if ((p1 = mmap(NULL, (size_t)length, PROT_READ,
71 	    MAP_PRIVATE, fd1, skip1)) == MAP_FAILED)
72 		goto mmap_failed;
73 	if ((p2 = mmap(NULL, (size_t)length, PROT_READ,
74 	    MAP_PRIVATE, fd2, skip2)) == MAP_FAILED) {
75 		munmap(p1, (size_t)length);
76 		goto mmap_failed;
77 	}
78 	if (length) {
79 		madvise(p1, length, MADV_SEQUENTIAL);
80 		madvise(p2, length, MADV_SEQUENTIAL);
81 	}
82 
83 	dfound = 0;
84 	for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
85 		if ((ch = *p1) != *p2) {
86 			if (lflag) {
87 				dfound = 1;
88 				(void)printf("%6lld %3o %3o\n", (long long)byte,
89 				    ch, *p2);
90 			} else
91 				diffmsg(file1, file2, byte, line);
92 				/* NOTREACHED */
93 		}
94 		if (ch == '\n')
95 			++line;
96 	}
97 
98 	if (len1 != len2)
99 		eofmsg (len1 > len2 ? file2 : file1);
100 	if (dfound)
101 		exit(DIFF_EXIT);
102 }
103