regular.c revision 61883 
1/*-
2 * Copyright (c) 1991, 1993, 1994
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: head/usr.bin/cmp/regular.c 61883 2000-06-20 20:28:40Z green $
34 *
35 */
36
37#ifndef lint
38static const char sccsid[] = "@(#)regular.c	8.3 (Berkeley) 4/2/94";
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#include <unistd.h>
51
52#include "extern.h"
53
54#define ROUNDPAGE(i) ((i) & ~pagemask)
55
56void
57c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
58	int fd1, fd2;
59	char *file1, *file2;
60	off_t skip1, len1, skip2, len2;
61{
62	u_char ch, *p1, *p2;
63	off_t byte, length, line;
64	int dfound;
65	off_t pagemask, off1, off2;
66	size_t pagesize;
67
68	if (skip1 > len1)
69		eofmsg(file1);
70	len1 -= skip1;
71	if (skip2 > len2)
72		eofmsg(file2);
73	len2 -= skip2;
74
75	if (sflag && len1 != len2)
76		exit(DIFF_EXIT);
77
78	pagesize = getpagesize();
79	pagemask = (off_t)pagesize - 1;
80	off1 = ROUNDPAGE(skip1);
81	off2 = ROUNDPAGE(skip2);
82
83	length = MIN(len1, len2);
84	if (length > SIZE_T_MAX)
85		return (c_special(fd1, file1, skip1, fd2, file2, skip2));
86
87	if ((p1 = (u_char *)mmap(NULL, (size_t)len1 + skip1 % pagesize,
88	    PROT_READ, MAP_SHARED, fd1, off1)) == (u_char *)MAP_FAILED)
89		err(ERR_EXIT, "%s", file1);
90
91	madvise(p1, len1 + skip1 % pagesize, MADV_SEQUENTIAL);
92	if ((p2 = (u_char *)mmap(NULL, (size_t)len2 + skip2 % pagesize,
93	    PROT_READ, MAP_SHARED, fd2, off2)) == (u_char *)MAP_FAILED)
94		err(ERR_EXIT, "%s", file2);
95	madvise(p2, len2 + skip2 % pagesize, MADV_SEQUENTIAL);
96
97	dfound = 0;
98	p1 += skip1 - off1;
99	p2 += skip2 - off2;
100	for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
101		if ((ch = *p1) != *p2) {
102			if (xflag) {
103				dfound = 1;
104				(void)printf("%08qx %02x %02x\n", byte - 1, ch, *p2);
105			} else if (lflag) {
106				dfound = 1;
107				(void)printf("%6qd %3o %3o\n", byte, ch, *p2);
108			} else
109				diffmsg(file1, file2, byte, line);
110				/* NOTREACHED */
111		}
112		if (ch == '\n')
113			++line;
114	}
115
116	if (len1 != len2)
117		eofmsg (len1 > len2 ? file2 : file1);
118	if (dfound)
119		exit(DIFF_EXIT);
120}
121