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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/types.h>
31#include <err.h>
32#include <limits.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <unistd.h>
36
37#include "extern.h"
38
39void
40c_link(const char *file1, off_t skip1, const char *file2, off_t skip2)
41{
42	char buf1[PATH_MAX], *p1;
43	char buf2[PATH_MAX], *p2;
44	int dfound, len1, len2;
45	off_t byte;
46	u_char ch;
47
48	if ((len1 = readlink(file1, buf1, sizeof(buf1) - 1)) < 0) {
49		if (!sflag)
50			err(ERR_EXIT, "%s", file1);
51		else
52			exit(ERR_EXIT);
53	}
54
55	if ((len2 = readlink(file2, buf2, sizeof(buf2) - 1)) < 0) {
56		if (!sflag)
57			err(ERR_EXIT, "%s", file2);
58		else
59			exit(ERR_EXIT);
60	}
61
62	if (skip1 > len1)
63		skip1 = len1;
64	buf1[len1] = '\0';
65
66	if (skip2 > len2)
67		skip2 = len2;
68	buf2[len2] = '\0';
69
70	dfound = 0;
71	byte = 1;
72	for (p1 = buf1 + skip1, p2 = buf2 + skip2; *p1 && *p2; p1++, p2++) {
73		if ((ch = *p1) != *p2) {
74			if (xflag) {
75				dfound = 1;
76				(void)printf("%08llx %02x %02x\n",
77				    (long long)byte - 1, ch, *p2);
78			} else if (lflag) {
79				dfound = 1;
80				(void)printf("%6lld %3o %3o\n",
81				    (long long)byte, ch, *p2);
82			} else
83				diffmsg(file1, file2, byte, 1);
84				/* NOTREACHED */
85		}
86		byte++;
87	}
88
89	if (*p1 || *p2)
90		eofmsg (*p1 ? file2 : file1);
91	if (dfound)
92		exit(DIFF_EXIT);
93}
94