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regular.c revision 1.13 
      1 /*	$NetBSD: regular.c,v 1.13 2005/02/06 20:50:34 dsl Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1991, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 #if 0
     35 static char sccsid[] = "@(#)regular.c	8.3 (Berkeley) 4/2/94";
     36 #else
     37 __RCSID("$NetBSD: regular.c,v 1.13 2005/02/06 20:50:34 dsl Exp $");
     38 #endif
     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 
     51 #include "extern.h"
     52 
     53 void
     54 c_regular(int fd1, char *file1, off_t skip1, off_t len1,
     55 	int fd2, char *file2, off_t skip2, off_t len2)
     56 {
     57 	u_char ch, *p1, *p2;
     58 	off_t byte, length, line;
     59 	int dfound;
     60 
     61 	if (sflag && len1 != len2)
     62 		exit(1);
     63 
     64 	if (skip1 > len1)
     65 		eofmsg(file1);
     66 	len1 -= skip1;
     67 	if (skip2 > len2)
     68 		eofmsg(file2);
     69 	len2 -= skip2;
     70 
     71 	length = MIN(len1, len2);
     72 	if (length > SIZE_T_MAX) {
     73 mmap_failed:
     74 		c_special(fd1, file1, skip1, fd2, file2, skip2);
     75 		return;
     76 	}
     77 
     78 	if ((p1 = (u_char *)mmap(NULL, (size_t)length,
     79 	    PROT_READ, MAP_FILE|MAP_SHARED, fd1, skip1)) == MAP_FAILED)
     80 		goto mmap_failed;
     81 	(void)madvise(p1, (size_t)length, MADV_SEQUENTIAL);
     82 
     83 	if ((p2 = (u_char *)mmap(NULL, (size_t)length,
     84 	    PROT_READ, MAP_FILE|MAP_SHARED, fd2, skip2)) == MAP_FAILED) {
     85 		munmap(p1, (size_t) length);
     86 		goto mmap_failed;
     87 	}
     88 	(void)madvise(p2, (size_t)length, MADV_SEQUENTIAL);
     89 
     90 	dfound = 0;
     91 	for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
     92 		if ((ch = *p1) != *p2) {
     93 			if (lflag) {
     94 				dfound = 1;
     95 				(void)printf("%6lld %3o %3o\n", (long long)byte,
     96 				    ch, *p2);
     97 			} else
     98 				diffmsg(file1, file2, byte, line);
     99 				/* NOTREACHED */
    100 		}
    101 		if (ch == '\n')
    102 			++line;
    103 	}
    104 
    105 	if (len1 != len2)
    106 		eofmsg (len1 > len2 ? file2 : file1);
    107 	if (dfound)
    108 		exit(DIFF_EXIT);
    109 }
    110