1/*-
2 * Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26#include <libgen.h>
27#include <string.h>
28
29char *
30(dirname)(char *path)
31{
32	char *end;
33
34	/*
35	 * If path is a null pointer or points to an empty string,
36	 * dirname() shall return a pointer to the string ".".
37	 */
38	if (path == NULL || *path == '\0')
39		return (__DECONST(char *, "."));
40
41	/* Find end of last pathname component. */
42	end = path + strlen(path);
43	while (end > path + 1 && *(end - 1) == '/')
44		--end;
45
46	/* Strip off the last pathname component. */
47	while (end > path && *(end - 1) != '/')
48		--end;
49
50	/*
51	 * If path does not contain a '/', then dirname() shall return a
52	 * pointer to the string ".".
53	 */
54	if (end == path) {
55		path[0] = '.';
56		path[1] = '\0';
57		return (path);
58	}
59
60	/*
61	 * Remove trailing slashes from the resulting directory name. Ensure
62	 * that at least one character remains.
63	 */
64	while (end > path + 1 && *(end - 1) == '/')
65		--end;
66
67	/* Null terminate directory name and return it. */
68	*end = '\0';
69	return (path);
70}
71