xref: /freebsd/crypto/openssh/openbsd-compat/dirname.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
1 /* OPENBSD ORIGINAL: lib/libc/gen/dirname.c */
2 
3 /*      $OpenBSD: dirname.c,v 1.10 2003/06/17 21:56:23 millert Exp $    */
4 
5 /*
6  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
7  *
8  * Permission to use, copy, modify, and distribute this software for any
9  * purpose with or without fee is hereby granted, provided that the above
10  * copyright notice and this permission notice appear in all copies.
11  *
12  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19  */
20 
21 #include "includes.h"
22 #ifndef HAVE_DIRNAME
23 
24 #ifndef lint
25 static char rcsid[] = "$OpenBSD: dirname.c,v 1.10 2003/06/17 21:56:23 millert Exp $";
26 #endif /* not lint */
27 
28 #include <errno.h>
29 #include <string.h>
30 #include <sys/param.h>
31 
32 char *
33 dirname(const char *path)
34 {
35 	static char bname[MAXPATHLEN];
36 	register const char *endp;
37 
38 	/* Empty or NULL string gets treated as "." */
39 	if (path == NULL || *path == '\0') {
40 		(void)strlcpy(bname, ".", sizeof bname);
41 		return(bname);
42 	}
43 
44 	/* Strip trailing slashes */
45 	endp = path + strlen(path) - 1;
46 	while (endp > path && *endp == '/')
47 		endp--;
48 
49 	/* Find the start of the dir */
50 	while (endp > path && *endp != '/')
51 		endp--;
52 
53 	/* Either the dir is "/" or there are no slashes */
54 	if (endp == path) {
55 		(void)strlcpy(bname, *endp == '/' ? "/" : ".", sizeof bname);
56 		return(bname);
57 	} else {
58 		do {
59 			endp--;
60 		} while (endp > path && *endp == '/');
61 	}
62 
63 	if (endp - path + 2 > sizeof(bname)) {
64 		errno = ENAMETOOLONG;
65 		return(NULL);
66 	}
67 	strlcpy(bname, path, endp - path + 2);
68 	return(bname);
69 }
70 #endif
71