/*      $NetBSD: special.c,v 1.14 2011/11/28 10:10:10 wiz Exp $ */

/*-
* 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. 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.
*/

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)special.c   8.3 (Berkeley) 4/2/94";
#else
__RCSID("$NetBSD: special.c,v 1.14 2011/11/28 10:10:10 wiz Exp $");
#endif
#endif /* not lint */

#include <sys/types.h>

#include <err.h>
#include <stdlib.h>
#include <stdio.h>

#include "extern.h"

void
c_special(int fd1, const char *file1, off_t skip1, int fd2, const char *file2, off_t skip2)
{
       int ch1, ch2;
       off_t byte, line;
       FILE *fp1, *fp2;
       int dfound;

       dfound = 0;
       if ((fp1 = fdopen(fd1, "r")) == NULL)
               err(ERR_EXIT, "%s", file1);
       if ((fp2 = fdopen(fd2, "r")) == NULL)
               err(ERR_EXIT, "%s", file2);

       for (byte = line = 1; skip1--; byte++) {
               ch1 = getc(fp1);
               if (ch1 == EOF)
                       goto eof;
               if (ch1 == '\n')
                       line++;
       }
       for (byte = line = 1; skip2--; byte++) {
               ch2 = getc(fp2);
               if (ch2 == EOF)
                       goto eof;
               if (ch2 == '\n')
                       line++;
       }
       dfound = 0;
       for (byte = line = 1;; ++byte) {
               ch1 = getc(fp1);
               ch2 = getc(fp2);
               if (ch1 == EOF || ch2 == EOF)
                       break;
               if (ch1 != ch2) {
                       if (lflag) {
                               dfound = 1;
                               (void)printf("%6lld %3o %3o\n", (long long)byte,
                                   ch1, ch2);
                       } else
                               diffmsg(file1, file2, byte, line);
                               /* NOTREACHED */
               }
               if (ch1 == '\n')
                       ++line;
       }

eof:
       if (ferror(fp1))
               errmsg(file1, byte, line);
       if (ferror(fp2))
               errmsg(file2, byte, line);
       if (feof(fp1)) {
               if (!feof(fp2))
                       eofmsg(file1, byte, line);
       } else
               if (feof(fp2))
                       eofmsg(file2, byte, line);
       (void)fclose(fp1);
       (void)fclose(fp2);
       if (dfound)
               exit(DIFF_EXIT);
}