xref: /freebsd/crypto/openssh/openbsd-compat/dirname.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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 
27 char *
28 dirname(const char *path)
29 {
30 	static char dname[MAXPATHLEN];
31 	size_t len;
32 	const char *endp;
33 
34 	/* Empty or NULL string gets treated as "." */
35 	if (path == NULL || *path == '\0') {
36 		dname[0] = '.';
37 		dname[1] = '\0';
38 		return (dname);
39 	}
40 
41 	/* Strip any trailing slashes */
42 	endp = path + strlen(path) - 1;
43 	while (endp > path && *endp == '/')
44 		endp--;
45 
46 	/* Find the start of the dir */
47 	while (endp > path && *endp != '/')
48 		endp--;
49 
50 	/* Either the dir is "/" or there are no slashes */
51 	if (endp == path) {
52 		dname[0] = *endp == '/' ? '/' : '.';
53 		dname[1] = '\0';
54 		return (dname);
55 	} else {
56 		/* Move forward past the separating slashes */
57 		do {
58 			endp--;
59 		} while (endp > path && *endp == '/');
60 	}
61 
62 	len = endp - path + 1;
63 	if (len >= sizeof(dname)) {
64 		errno = ENAMETOOLONG;
65 		return (NULL);
66 	}
67 	memcpy(dname, path, len);
68 	dname[len] = '\0';
69 	return (dname);
70 }
71 #endif
72