usr.bin/cmp/regular.c

   1 /*      $NetBSD: regular.c,v 1.21 2009/04/11 12:16:12 lukem 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 1.21 2009/04/11 12:16:12 lukem 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, const char *file1, off_t skip1, off_t len1,
  55     int fd2, const 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         size_t blk_sz, blk_cnt;
  61
  62         if (sflag && len1 != len2)
  63                 exit(1);
  64
  65         if (skip1 > len1)
  66                 eofmsg(file1, len1 + 1, 0);
  67         len1 -= skip1;
  68         if (skip2 > len2)
  69                 eofmsg(file2, len2 + 1, 0);
  70         len2 -= skip2;
  71
  72         byte = line = 1;
  73         dfound = 0;
  74         length = MIN(len1, len2);
  75         for (blk_sz = 1024 * 1024; length != 0; length -= blk_sz) {
  76                 if ((uintmax_t)blk_sz > (uintmax_t)length)
  77                         blk_sz = length;
  78                 p1 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED,
  79                     fd1, skip1);
  80                 if (p1 == MAP_FAILED)
  81                         goto mmap_failed;
  82
  83                 p2 = mmap(NULL, blk_sz, PROT_READ, MAP_FILE|MAP_SHARED,
  84                     fd2, skip2);
  85                 if (p2 == MAP_FAILED) {
  86                         munmap(p1, blk_sz);
  87                         goto mmap_failed;
  88                 }
  89
  90                 blk_cnt = blk_sz;
  91                 for (; blk_cnt--; ++p1, ++p2, ++byte) {
  92                         if ((ch = *p1) != *p2) {
  93                                 if (!lflag) {
  94                                         diffmsg(file1, file2, byte, line);
  95                                         /* NOTREACHED */
  96                                 }
  97                                 dfound = 1;
  98                                 (void)printf("%6lld %3o %3o\n",
  99                                     (long long)byte, ch, *p2);
 100                         }
 101                         if (ch == '\n')
 102                                 ++line;
 103                 }
 104                 munmap(p1 - blk_sz, blk_sz);
 105                 munmap(p2 - blk_sz, blk_sz);
 106                 skip1 += blk_sz;
 107                 skip2 += blk_sz;
 108         }
 109
 110         if (len1 != len2)
 111                 eofmsg(len1 > len2 ? file2 : file1, byte, line);
 112         if (dfound)
 113                 exit(DIFF_EXIT);
 114         return;
 115
 116 mmap_failed:
 117         c_special(fd1, file1, skip1, fd2, file2, skip2);
 118 }