dirname.c revision 90016 
1/*
2 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
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 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
17 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
18 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
19 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#if 0
29#ifndef lint
30static char rcsid[] = "$OpenBSD: dirname.c,v 1.4 1999/05/30 17:10:30 espie Exp $";
31#endif /* not lint */
32#endif
33
34#include <sys/cdefs.h>
35__FBSDID("$FreeBSD: head/lib/libc/gen/dirname.c 90016 2002-01-31 12:58:36Z bde $");
36
37#include <errno.h>
38#include <libgen.h>
39#include <string.h>
40#include <sys/param.h>
41
42char *
43dirname(path)
44	const char *path;
45{
46	static char bname[MAXPATHLEN];
47	register const char *endp;
48
49	/* Empty or NULL string gets treated as "." */
50	if (path == NULL || *path == '\0') {
51		(void)strcpy(bname, ".");
52		return(bname);
53	}
54
55	/* Strip trailing slashes */
56	endp = path + strlen(path) - 1;
57	while (endp > path && *endp == '/')
58		endp--;
59
60	/* Find the start of the dir */
61	while (endp > path && *endp != '/')
62		endp--;
63
64	/* Either the dir is "/" or there are no slashes */
65	if (endp == path) {
66		(void)strcpy(bname, *endp == '/' ? "/" : ".");
67		return(bname);
68	} else {
69		do {
70			endp--;
71		} while (endp > path && *endp == '/');
72	}
73
74	if (endp - path + 2 > sizeof(bname)) {
75		errno = ENAMETOOLONG;
76		return(NULL);
77	}
78	(void)strncpy(bname, path, endp - path + 1);
79	bname[endp - path + 1] = '\0';
80	return(bname);
81}
82