1/*	$OpenBSD: dirname.c,v 1.13 2005/08/08 08:05:33 espie Exp $	*/
2
3/*
4 * Copyright (c) 1997, 2004 Todd C. Miller <Todd.Miller@courtesan.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/cdefs.h>
20__FBSDID("$FreeBSD: src/lib/libc/gen/dirname.c,v 1.8 2008/11/03 05:19:45 delphij Exp $");
21
22#include <errno.h>
23#include <libgen.h>
24#include <stdlib.h>
25#include <string.h>
26#include <sys/param.h>
27
28#if __DARWIN_UNIX03
29#define const /**/
30#endif
31
32char *
33dirname(const char *path)
34{
35	static char *dname = NULL;
36	size_t len;
37	const char *endp;
38
39	if (dname == NULL) {
40		dname = (char *)malloc(MAXPATHLEN);
41		if (dname == NULL)
42			return(NULL);
43	}
44
45	/* Empty or NULL string gets treated as "." */
46	if (path == NULL || *path == '\0') {
47		dname[0] = '.';
48		dname[1] = '\0';
49		return (dname);
50	}
51
52	/* Strip any trailing slashes */
53	endp = path + strlen(path) - 1;
54	while (endp > path && *endp == '/')
55		endp--;
56
57	/* Find the start of the dir */
58	while (endp > path && *endp != '/')
59		endp--;
60
61	/* Either the dir is "/" or there are no slashes */
62	if (endp == path) {
63		dname[0] = *endp == '/' ? '/' : '.';
64		dname[1] = '\0';
65		return (dname);
66	} else {
67		/* Move forward past the separating slashes */
68		do {
69			endp--;
70		} while (endp > path && *endp == '/');
71	}
72
73	len = endp - path + 1;
74	if (len >= MAXPATHLEN) {
75		errno = ENAMETOOLONG;
76		return (NULL);
77	}
78	memcpy(dname, path, len);
79	dname[len] = '\0';
80	return (dname);
81}
82