regular.c revision 21786 
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
34#ifndef lint
35static char sccsid[] = "@(#)regular.c	8.3 (Berkeley) 4/2/94";
36#endif /* not lint */
37
38#include <sys/param.h>
39#include <sys/mman.h>
40#include <sys/stat.h>
41
42#include <err.h>
43#include <limits.h>
44#include <stdlib.h>
45#include <stdio.h>
46#include <string.h>
47#include <unistd.h>
48
49#include "extern.h"
50
51#define ROUNDPAGE(i) ((i) & ~pagemask)
52
53void
54c_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	off_t pagemask, off1, off2;
63
64	if (sflag && len1 != len2)
65		exit(1);
66
67	if (skip1 > len1)
68		eofmsg(file1);
69	len1 -= skip1;
70	if (skip2 > len2)
71		eofmsg(file2);
72	len2 -= skip2;
73
74	pagemask = (off_t)getpagesize() - 1;
75	off1 = ROUNDPAGE(skip1);
76	off2 = ROUNDPAGE(skip2);
77
78	length = MIN(len1, len2);
79	if (length > SIZE_T_MAX)
80		return (c_special(fd1, file1, skip1, fd2, file2, skip2));
81
82	if ((p1 = (u_char *)mmap(NULL,
83	    (size_t)length, PROT_READ, MAP_SHARED, fd1, off1)) == (u_char *)MAP_FAILED)
84		err(ERR_EXIT, "%s", file1);
85
86	madvise(p1, length, MADV_SEQUENTIAL);
87	if ((p2 = (u_char *)mmap(NULL,
88	    (size_t)length, PROT_READ, MAP_SHARED, fd2, off2)) == (u_char *)MAP_FAILED)
89		err(ERR_EXIT, "%s", file2);
90	madvise(p2, length, MADV_SEQUENTIAL);
91
92	dfound = 0;
93	p1 += skip1 - off1;
94	p2 += skip2 - off2;
95	for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
96		if ((ch = *p1) != *p2)
97			if (lflag) {
98				dfound = 1;
99				(void)printf("%6qd %3o %3o\n", byte, ch, *p2);
100			} else
101				diffmsg(file1, file2, byte, line);
102				/* NOTREACHED */
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