1/*
2 * Copyright (C) 2008 The Android Open Source Project
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 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28#include <libgen.h>
29#include <errno.h>
30#include <string.h>
31#include <sys/param.h>
32
33int
34dirname_r(const char*  path, char*  buffer, size_t  bufflen)
35{
36    const char *endp;
37    int         result, len;
38
39    /* Empty or NULL string gets treated as "." */
40    if (path == NULL || *path == '\0') {
41        path = ".";
42        len  = 1;
43        goto Exit;
44    }
45
46    /* Strip trailing slashes */
47    endp = path + strlen(path) - 1;
48    while (endp > path && *endp == '/')
49        endp--;
50
51    /* Find the start of the dir */
52    while (endp > path && *endp != '/')
53        endp--;
54
55    /* Either the dir is "/" or there are no slashes */
56    if (endp == path) {
57        path = (*endp == '/') ? "/" : ".";
58        len  = 1;
59        goto Exit;
60    }
61
62    do {
63        endp--;
64    } while (endp > path && *endp == '/');
65
66    len = endp - path +1;
67
68Exit:
69    result = len;
70    if (len+1 > MAXPATHLEN) {
71        errno = ENAMETOOLONG;
72        return -1;
73    }
74    if (buffer == NULL)
75        return result;
76
77    if (len > (int)bufflen-1) {
78        len    = (int)bufflen-1;
79        result = -1;
80        errno  = ERANGE;
81    }
82
83    if (len >= 0) {
84        memcpy( buffer, path, len );
85        buffer[len] = 0;
86    }
87    return result;
88}
89