1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005 Brian Somers <brian@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: head/usr.bin/cmp/link.c 149388 2005-08-23 13:13:13Z brian $
29 */
30
31 #include <sys/types.h>
32 #include <err.h>
33 #include <limits.h>
34 #include <stdbool.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38
39 #include "extern.h"
40
41 void
c_link(const char * file1,off_t skip1,const char * file2,off_t skip2)42 c_link(const char *file1, off_t skip1, const char *file2, off_t skip2)
43 {
44 char buf1[PATH_MAX], *p1;
45 char buf2[PATH_MAX], *p2;
46 int dfound, len1, len2;
47 off_t byte;
48 u_char ch;
49
50 if ((len1 = readlink(file1, buf1, sizeof(buf1) - 1)) < 0) {
51 if (!sflag)
52 err(ERR_EXIT, "%s", file1);
53 else
54 exit(ERR_EXIT);
55 }
56
57 if ((len2 = readlink(file2, buf2, sizeof(buf2) - 1)) < 0) {
58 if (!sflag)
59 err(ERR_EXIT, "%s", file2);
60 else
61 exit(ERR_EXIT);
62 }
63
64 if (skip1 > len1)
65 skip1 = len1;
66 buf1[len1] = '\0';
67
68 if (skip2 > len2)
69 skip2 = len2;
70 buf2[len2] = '\0';
71
72 dfound = 0;
73 byte = 1;
74 for (p1 = buf1 + skip1, p2 = buf2 + skip2; *p1 && *p2; p1++, p2++) {
75 if ((ch = *p1) != *p2) {
76 if (xflag) {
77 dfound = 1;
78 (void)printf("%08llx %02x %02x\n",
79 (long long)byte - 1, ch, *p2);
80 } else if (lflag) {
81 dfound = 1;
82 (void)printf("%6lld %3o %3o\n",
83 (long long)byte, ch, *p2);
84 } else
85 diffmsg(file1, file2, byte, 1);
86 /* NOTREACHED */
87 }
88 byte++;
89 }
90
91 if (*p1 || *p2)
92 eofmsg (*p1 ? file2 : file1);
93 if (dfound)
94 exit(DIFF_EXIT);
95 }
96