dirname.c revision 98937 
1/*	$OpenBSD: dirname.c,v 1.6 2001/06/28 04:27:19 pjanzen Exp $	*/
2
3/*
4 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include "includes.h"
31#ifndef HAVE_DIRNAME
32
33#if defined(LIBC_SCCS) && !defined(lint)
34static char rcsid[] = "$OpenBSD: dirname.c,v 1.6 2001/06/28 04:27:19 pjanzen Exp $";
35#endif /* LIBC_SCCS and not lint */
36
37#include <errno.h>
38#include <string.h>
39#include <sys/param.h>
40
41char *
42dirname(path)
43	const char *path;
44{
45	static char bname[MAXPATHLEN];
46	register const char *endp;
47
48	/* Empty or NULL string gets treated as "." */
49	if (path == NULL || *path == '\0') {
50		(void)strcpy(bname, ".");
51		return(bname);
52	}
53
54	/* Strip trailing slashes */
55	endp = path + strlen(path) - 1;
56	while (endp > path && *endp == '/')
57		endp--;
58
59	/* Find the start of the dir */
60	while (endp > path && *endp != '/')
61		endp--;
62
63	/* Either the dir is "/" or there are no slashes */
64	if (endp == path) {
65		(void)strcpy(bname, *endp == '/' ? "/" : ".");
66		return(bname);
67	} else {
68		do {
69			endp--;
70		} while (endp > path && *endp == '/');
71	}
72
73	if (endp - path + 2 > sizeof(bname)) {
74		errno = ENAMETOOLONG;
75		return(NULL);
76	}
77	strlcpy(bname, path, endp - path + 2);
78	return(bname);
79}
80#endif
81