1/*      $OpenBSD: special.c,v 1.8 2018/03/05 16:53:39 cheloha Exp $      */
2/*      $NetBSD: special.c,v 1.2 1995/09/08 03:23:00 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/types.h>
34
35#include <err.h>
36#include <stdlib.h>
37#include <stdio.h>
38#include <string.h>
39
40#include "extern.h"
41
42void
43c_special(int fd1, char *file1, off_t skip1, int fd2, char *file2, off_t skip2)
44{
45	int ch1, ch2;
46	off_t byte, line;
47	FILE *fp1, *fp2;
48	int dfound;
49
50	if ((fp1 = fdopen(fd1, "r")) == NULL)
51		fatal("%s", file1);
52	if ((fp2 = fdopen(fd2, "r")) == NULL)
53		fatal("%s", file2);
54
55	dfound = 0;
56	while (skip1--)
57		if (getc(fp1) == EOF)
58			goto eof;
59	while (skip2--)
60		if (getc(fp2) == EOF)
61			goto eof;
62
63	for (byte = line = 1;; ++byte) {
64		ch1 = getc(fp1);
65		ch2 = getc(fp2);
66		if (ch1 == EOF || ch2 == EOF)
67			break;
68		if (ch1 != ch2) {
69			if (lflag) {
70				dfound = 1;
71				(void)printf("%6lld %3o %3o\n", (long long)byte,
72				    ch1, ch2);
73			} else
74				diffmsg(file1, file2, byte, line);
75				/* NOTREACHED */
76		}
77		if (ch1 == '\n')
78			++line;
79	}
80
81eof:	if (ferror(fp1))
82		fatal("%s", file1);
83	if (ferror(fp2))
84		fatal("%s", file2);
85	if (feof(fp1)) {
86		if (!feof(fp2))
87			eofmsg(file1);
88	} else
89		if (feof(fp2))
90			eofmsg(file2);
91	if (dfound)
92		exit(DIFF_EXIT);
93}
94