1 /* $OpenBSD: dirname.c,v 1.4 1999/05/30 17:10:30 espie 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 #ifndef lint
31 static char rcsid[] = "$OpenBSD: dirname.c,v 1.4 1999/05/30 17:10:30 espie Exp $";
32 #endif /* not lint */
33
34 #include <sys/types.h>
35
36 #include "config.h"
37
38 #include <errno.h>
39 #include <string.h>
40 #include <sys/param.h>
41
42 char *
dirname(path)43 dirname(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 + 1 > 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