special.c revision 314425 
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 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if 0
31#ifndef lint
32static char sccsid[] = "@(#)special.c	8.3 (Berkeley) 4/2/94";
33#endif
34#endif
35
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD: stable/10/usr.bin/cmp/special.c 314425 2017-02-28 22:18:05Z asomers $");
38
39#include <sys/types.h>
40
41#include <err.h>
42#include <stdlib.h>
43#include <stdio.h>
44
45#include "extern.h"
46
47void
48c_special(int fd1, const char *file1, off_t skip1,
49    int fd2, const char *file2, off_t skip2)
50{
51	int ch1, ch2;
52	off_t byte, line;
53	FILE *fp1, *fp2;
54	int dfound;
55
56	if ((fp1 = fdopen(fd1, "r")) == NULL)
57		err(ERR_EXIT, "%s", file1);
58	if ((fp2 = fdopen(fd2, "r")) == NULL)
59		err(ERR_EXIT, "%s", file2);
60
61	dfound = 0;
62	while (skip1--)
63		if (getc(fp1) == EOF)
64			goto eof;
65	while (skip2--)
66		if (getc(fp2) == EOF)
67			goto eof;
68
69	for (byte = line = 1;; ++byte) {
70		ch1 = getc(fp1);
71		ch2 = getc(fp2);
72		if (ch1 == EOF || ch2 == EOF)
73			break;
74		if (ch1 != ch2) {
75			if (xflag) {
76				dfound = 1;
77				(void)printf("%08llx %02x %02x\n",
78				    (long long)byte - 1, ch1, ch2);
79			} else if (lflag) {
80				dfound = 1;
81				(void)printf("%6lld %3o %3o\n",
82				    (long long)byte, ch1, ch2);
83			} else {
84				diffmsg(file1, file2, byte, line);
85				/* NOTREACHED */
86			}
87		}
88		if (ch1 == '\n')
89			++line;
90	}
91
92eof:	if (ferror(fp1))
93		err(ERR_EXIT, "%s", file1);
94	if (ferror(fp2))
95		err(ERR_EXIT, "%s", file2);
96	if (feof(fp1)) {
97		if (!feof(fp2))
98			eofmsg(file1);
99	} else
100		if (feof(fp2))
101			eofmsg(file2);
102	fclose(fp2);
103	fclose(fp1);
104	if (dfound)
105		exit(DIFF_EXIT);
106}
107