1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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
29 #include <sys/types.h>
30
31 #include <err.h>
32 #include <limits.h>
33 #include <stdbool.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37
38 #include "extern.h"
39
40 int
c_link(const char * file1,off_t skip1,const char * file2,off_t skip2,off_t limit)41 c_link(const char *file1, off_t skip1, const char *file2, off_t skip2,
42 off_t limit)
43 {
44 char buf1[PATH_MAX], *p1;
45 char buf2[PATH_MAX], *p2;
46 ssize_t len1, len2;
47 int dfound;
48 off_t byte;
49 u_char ch;
50
51 if ((len1 = readlink(file1, buf1, sizeof(buf1) - 1)) < 0) {
52 if (!sflag)
53 err(ERR_EXIT, "%s", file1);
54 else
55 exit(ERR_EXIT);
56 }
57
58 if ((len2 = readlink(file2, buf2, sizeof(buf2) - 1)) < 0) {
59 if (!sflag)
60 err(ERR_EXIT, "%s", file2);
61 else
62 exit(ERR_EXIT);
63 }
64
65 if (skip1 > len1)
66 skip1 = len1;
67 buf1[len1] = '\0';
68
69 if (skip2 > len2)
70 skip2 = len2;
71 buf2[len2] = '\0';
72
73 dfound = 0;
74 byte = 1;
75 for (p1 = buf1 + skip1, p2 = buf2 + skip2;
76 *p1 && *p2 && (limit == 0 || byte <= limit); p1++, p2++) {
77 if ((ch = *p1) != *p2) {
78 if (xflag) {
79 dfound = 1;
80 (void)printf("%08llx %02x %02x\n",
81 (long long)byte - 1, ch, *p2);
82 } else if (lflag) {
83 dfound = 1;
84 if (bflag)
85 (void)printf("%6lld %3o %c %3o %c\n",
86 (long long)byte, ch, ch, *p2, *p2);
87 else
88 (void)printf("%6lld %3o %3o\n",
89 (long long)byte, ch, *p2);
90 } else {
91 diffmsg(file1, file2, byte, 1, ch, *p2);
92 return (DIFF_EXIT);
93 }
94 }
95 byte++;
96 }
97
98 if (*p1 || *p2) {
99 eofmsg (*p1 ? file2 : file1);
100 return (DIFF_EXIT);
101 }
102 return (dfound ? DIFF_EXIT : 0);
103 }
104