xref: /freebsd/crypto/openssh/openbsd-compat/dirname.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
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 /* OPENBSD ORIGINAL: lib/libc/gen/dirname.c */
20 
21 #include "includes.h"
22 #ifndef HAVE_DIRNAME
23 
24 #include <errno.h>
25 #include <string.h>
26 #include <sys/param.h>
27 
28 char *
29 dirname(const char *path)
30 {
31 	static char dname[MAXPATHLEN];
32 	size_t len;
33 	const char *endp;
34 
35 	/* Empty or NULL string gets treated as "." */
36 	if (path == NULL || *path == '\0') {
37 		dname[0] = '.';
38 		dname[1] = '\0';
39 		return (dname);
40 	}
41 
42 	/* Strip any trailing slashes */
43 	endp = path + strlen(path) - 1;
44 	while (endp > path && *endp == '/')
45 		endp--;
46 
47 	/* Find the start of the dir */
48 	while (endp > path && *endp != '/')
49 		endp--;
50 
51 	/* Either the dir is "/" or there are no slashes */
52 	if (endp == path) {
53 		dname[0] = *endp == '/' ? '/' : '.';
54 		dname[1] = '\0';
55 		return (dname);
56 	} else {
57 		/* Move forward past the separating slashes */
58 		do {
59 			endp--;
60 		} while (endp > path && *endp == '/');
61 	}
62 
63 	len = endp - path + 1;
64 	if (len >= sizeof(dname)) {
65 		errno = ENAMETOOLONG;
66 		return (NULL);
67 	}
68 	memcpy(dname, path, len);
69 	dname[len] = '\0';
70 	return (dname);
71 }
72 #endif
73