usr.bin/cmp/link.c

   1 /*-
   2  * Copyright (c) 2005 Brian Somers <brian@FreeBSD.org>
   3  * 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  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: head/usr.bin/cmp/link.c 149388 2005-08-23 13:13:13Z brian $
  27  */
  28
  29 #include <sys/types.h>
  30 #include <err.h>
  31 #include <limits.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <unistd.h>
  35
  36 #include "extern.h"
  37
  38 void
  39 c_link(const char *file1, off_t skip1, const char *file2, off_t skip2)
  40 {
  41         char buf1[PATH_MAX], *p1;
  42         char buf2[PATH_MAX], *p2;
  43         int dfound, len1, len2;
  44         off_t byte;
  45         u_char ch;
  46
  47         if ((len1 = readlink(file1, buf1, sizeof(buf1) - 1)) < 0) {
  48                 if (!sflag)
  49                         err(ERR_EXIT, "%s", file1);
  50                 else
  51                         exit(ERR_EXIT);
  52         }
  53
  54         if ((len2 = readlink(file2, buf2, sizeof(buf2) - 1)) < 0) {
  55                 if (!sflag)
  56                         err(ERR_EXIT, "%s", file2);
  57                 else
  58                         exit(ERR_EXIT);
  59         }
  60
  61         if (skip1 > len1)
  62                 skip1 = len1;
  63         buf1[len1] = '\0';
  64
  65         if (skip2 > len2)
  66                 skip2 = len2;
  67         buf2[len2] = '\0';
  68
  69         dfound = 0;
  70         byte = 1;
  71         for (p1 = buf1 + skip1, p2 = buf2 + skip2; *p1 && *p2; p1++, p2++) {
  72                 if ((ch = *p1) != *p2) {
  73                         if (xflag) {
  74                                 dfound = 1;
  75                                 (void)printf("%08llx %02x %02x\n",
  76                                     (long long)byte - 1, ch, *p2);
  77                         } else if (lflag) {
  78                                 dfound = 1;
  79                                 (void)printf("%6lld %3o %3o\n",
  80                                     (long long)byte, ch, *p2);
  81                         } else
  82                                 diffmsg(file1, file2, byte, 1);
  83                                 /* NOTREACHED */
  84                 }
  85                 byte++;
  86         }
  87
  88         if (*p1 || *p2)
  89                 eofmsg (*p1 ? file2 : file1);
  90         if (dfound)
  91                 exit(DIFF_EXIT);
  92 }