freebsd-dev/usr.bin/cmp/regular.c
1999-07-29 23:26:22 +00:00

115 lines
3.6 KiB
C

/*-
* Copyright (c) 1991, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char sccsid[] = "@(#)regular.c 8.3 (Berkeley) 4/2/94";
#endif /* not lint */
#include <sys/param.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <err.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "extern.h"
#define ROUNDPAGE(i) ((i) & ~pagemask)
void
c_regular(fd1, file1, skip1, len1, fd2, file2, skip2, len2)
int fd1, fd2;
char *file1, *file2;
off_t skip1, len1, skip2, len2;
{
u_char ch, *p1, *p2;
off_t byte, length, line;
int dfound;
off_t pagemask, off1, off2;
size_t pagesize;
if (sflag && len1 != len2)
exit(1);
if (skip1 > len1)
eofmsg(file1);
len1 -= skip1;
if (skip2 > len2)
eofmsg(file2);
len2 -= skip2;
pagesize = getpagesize();
pagemask = (off_t)pagesize - 1;
off1 = ROUNDPAGE(skip1);
off2 = ROUNDPAGE(skip2);
length = MIN(len1, len2);
if (length > SIZE_T_MAX)
return (c_special(fd1, file1, skip1, fd2, file2, skip2));
if ((p1 = (u_char *)mmap(NULL, (size_t)len1 + skip1 % pagesize,
PROT_READ, MAP_SHARED, fd1, off1)) == (u_char *)MAP_FAILED)
err(ERR_EXIT, "%s", file1);
madvise(p1, len1 + skip1 % pagesize, MADV_SEQUENTIAL);
if ((p2 = (u_char *)mmap(NULL, (size_t)len2 + skip2 % pagesize,
PROT_READ, MAP_SHARED, fd2, off2)) == (u_char *)MAP_FAILED)
err(ERR_EXIT, "%s", file2);
madvise(p2, len2 + skip2 % pagesize, MADV_SEQUENTIAL);
dfound = 0;
p1 += skip1 - off1;
p2 += skip2 - off2;
for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
if ((ch = *p1) != *p2) {
if (lflag) {
dfound = 1;
(void)printf("%6qd %3o %3o\n", byte, ch, *p2);
} else
diffmsg(file1, file2, byte, line);
/* NOTREACHED */
}
if (ch == '\n')
++line;
}
if (len1 != len2)
eofmsg (len1 > len2 ? file2 : file1);
if (dfound)
exit(DIFF_EXIT);
}