1 /* $NetBSD: dirname.c,v 1.13 2014/07/16 10:52:26 christos Exp $ */
2
3 /*-
4 * Copyright (c) 1997, 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Klaus Klein and Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 __RCSID("$NetBSD: dirname.c,v 1.13 2014/07/16 10:52:26 christos Exp $");
35 #endif /* !LIBC_SCCS && !lint */
36
37 #include "namespace.h"
38 #include <sys/param.h>
39 #include <libgen.h>
40 #include <limits.h>
41 #include <string.h>
42
43 #ifdef __weak_alias
__weak_alias(dirname,_dirname)44 __weak_alias(dirname,_dirname)
45 #endif
46
47 static size_t
48 xdirname_r(const char *path, char *buf, size_t buflen)
49 {
50 const char *endp;
51 size_t len;
52
53 /*
54 * If `path' is a null pointer or points to an empty string,
55 * return a pointer to the string ".".
56 */
57 if (path == NULL || *path == '\0') {
58 path = ".";
59 len = 1;
60 goto out;
61 }
62
63 /* Strip trailing slashes, if any. */
64 endp = path + strlen(path) - 1;
65 while (endp != path && *endp == '/')
66 endp--;
67
68 /* Find the start of the dir */
69 while (endp > path && *endp != '/')
70 endp--;
71
72 if (endp == path) {
73 path = *endp == '/' ? "/" : ".";
74 len = 1;
75 goto out;
76 }
77
78 do
79 endp--;
80 while (endp > path && *endp == '/');
81
82 len = endp - path + 1;
83 out:
84 if (buf != NULL && buflen != 0) {
85 buflen = MIN(len, buflen - 1);
86 memcpy(buf, path, buflen);
87 buf[buflen] = '\0';
88 }
89 return len;
90 }
91
92 #if !HAVE_DIRNAME
93 char *
dirname(char * path)94 dirname(char *path)
95 {
96 static char result[PATH_MAX];
97 (void)xdirname_r(path, result, sizeof(result));
98 return result;
99 }
100 #endif
101