bin/cmp/regular.c

   1 /*      $OpenBSD: regular.c,v 1.12 2015/02/06 23:21:59 millert Exp $      */
   2 /*      $NetBSD: regular.c,v 1.2 1995/09/08 03:22:59 tls Exp $      */
   3
   4 /*-
   5  * Copyright (c) 1991, 1993, 1994
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <sys/mman.h>
  34 #include <sys/stat.h>
  35
  36 #include <err.h>
  37 #include <stdint.h>
  38 #include <stdlib.h>
  39 #include <stdio.h>
  40 #include <string.h>
  41
  42 #include "extern.h"
  43
  44 #define MINIMUM(a, b)   (((a) < (b)) ? (a) : (b))
  45
  46 void
  47 c_regular(int fd1, char *file1, off_t skip1, off_t len1,
  48     int fd2, char *file2, off_t skip2, off_t len2)
  49 {
  50         char ch, *p1, *p2;
  51         off_t byte, length, line;
  52         int dfound;
  53
  54         if (sflag && len1 != len2)
  55                 exit(1);
  56
  57         if (skip1 > len1)
  58                 eofmsg(file1);
  59         len1 -= skip1;
  60         if (skip2 > len2)
  61                 eofmsg(file2);
  62         len2 -= skip2;
  63
  64         length = MINIMUM(len1, len2);
  65         if (length > SIZE_MAX) {
  66         mmap_failed:
  67                 c_special(fd1, file1, skip1, fd2, file2, skip2);
  68                 return;
  69         }
  70
  71         if ((p1 = mmap(NULL, (size_t)length, PROT_READ,
  72             MAP_PRIVATE, fd1, skip1)) == MAP_FAILED)
  73                 goto mmap_failed;
  74         if ((p2 = mmap(NULL, (size_t)length, PROT_READ,
  75             MAP_PRIVATE, fd2, skip2)) == MAP_FAILED) {
  76                 munmap(p1, (size_t)length);
  77                 goto mmap_failed;
  78         }
  79         if (length) {
  80                 madvise(p1, length, MADV_SEQUENTIAL);
  81                 madvise(p2, length, MADV_SEQUENTIAL);
  82         }
  83
  84         dfound = 0;
  85         for (byte = line = 1; length--; ++p1, ++p2, ++byte) {
  86                 if ((ch = *p1) != *p2) {
  87                         if (lflag) {
  88                                 dfound = 1;
  89                                 (void)printf("%6lld %3o %3o\n", (long long)byte,
  90                                     ch, *p2);
  91                         } else
  92                                 diffmsg(file1, file2, byte, line);
  93                                 /* NOTREACHED */
  94                 }
  95                 if (ch == '\n')
  96                         ++line;
  97         }
  98
  99         if (len1 != len2)
 100                 eofmsg (len1 > len2 ? file2 : file1);
 101         if (dfound)
 102                 exit(DIFF_EXIT);
 103 }