usr.bin/cmp/special.c

   1 /*-
   2  * Copyright (c) 1991, 1993, 1994
   3  *      The Regents of the University of California.  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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * $FreeBSD: src/usr.bin/cmp/special.c,v 1.4.2.1 2001/11/21 10:47:54 dwmalone Exp $
  34  * $DragonFly: src/usr.bin/cmp/special.c,v 1.3 2003/10/02 17:42:27 hmp Exp $
  35  *
  36  * @(#)special.c        8.3 (Berkeley) 4/2/94
  37  */
  38
  39 #include <sys/types.h>
  40
  41 #include <err.h>
  42 #include <stdlib.h>
  43 #include <stdio.h>
  44 #include <string.h>
  45
  46 #include "extern.h"
  47
  48 void
  49 c_special(int fd1, const char *file1, off_t skip1, int fd2, const char *file2,
  50           off_t skip2)
  51 {
  52         int ch1, ch2;
  53         off_t byte, line;
  54         FILE *fp1, *fp2;
  55         int dfound;
  56
  57         if ((fp1 = fdopen(fd1, "r")) == NULL)
  58                 err(ERR_EXIT, "%s", file1);
  59         if ((fp2 = fdopen(fd2, "r")) == NULL)
  60                 err(ERR_EXIT, "%s", file2);
  61
  62         dfound = 0;
  63         while (skip1--)
  64                 if (getc(fp1) == EOF)
  65                         goto eof;
  66         while (skip2--)
  67                 if (getc(fp2) == EOF)
  68                         goto eof;
  69
  70         for (byte = line = 1;; ++byte) {
  71                 ch1 = getc(fp1);
  72                 ch2 = getc(fp2);
  73                 if (ch1 == EOF || ch2 == EOF)
  74                         break;
  75                 if (ch1 != ch2) {
  76                         if (lflag) {
  77                                 dfound = 1;
  78                                 (void)printf("%6qd %3o %3o\n", byte, ch1, ch2);
  79                         } else {
  80                                 diffmsg(file1, file2, byte, line);
  81                                 /* NOTREACHED */
  82                         }
  83                 }
  84                 if (ch1 == '\n')
  85                         ++line;
  86         }
  87
  88 eof:    if (ferror(fp1))
  89                 err(ERR_EXIT, "%s", file1);
  90         if (ferror(fp2))
  91                 err(ERR_EXIT, "%s", file2);
  92         if (feof(fp1)) {
  93                 if (!feof(fp2))
  94                         eofmsg(file1);
  95         } else
  96                 if (feof(fp2))
  97                         eofmsg(file2);
  98         if (dfound)
  99                 exit(DIFF_EXIT);
 100 }