xref: /dragonfly/lib/libc/gen/basename.c (revision 984263bc)
1 /*	$OpenBSD: basename.c,v 1.4 1999/05/30 17:10:30 espie Exp $	*/
2 /*	$FreeBSD: src/lib/libc/gen/basename.c,v 1.1.2.2 2001/07/23 10:13:04 dd Exp $	*/
3 
4 /*
5  * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
20  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
22  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
25  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
28  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #ifndef lint
32 static char rcsid[] = "$OpenBSD: basename.c,v 1.4 1999/05/30 17:10:30 espie Exp $";
33 #endif /* not lint */
34 
35 #include <errno.h>
36 #include <libgen.h>
37 #include <string.h>
38 #include <sys/param.h>
39 
40 char *
41 basename(path)
42 	const char *path;
43 {
44 	static char bname[MAXPATHLEN];
45 	register const char *endp, *startp;
46 
47 	/* Empty or NULL string gets treated as "." */
48 	if (path == NULL || *path == '\0') {
49 		(void)strcpy(bname, ".");
50 		return(bname);
51 	}
52 
53 	/* Strip trailing slashes */
54 	endp = path + strlen(path) - 1;
55 	while (endp > path && *endp == '/')
56 		endp--;
57 
58 	/* All slashes becomes "/" */
59 	if (endp == path && *endp == '/') {
60 		(void)strcpy(bname, "/");
61 		return(bname);
62 	}
63 
64 	/* Find the start of the base */
65 	startp = endp;
66 	while (startp > path && *(startp - 1) != '/')
67 		startp--;
68 
69 	if (endp - startp + 2 > sizeof(bname)) {
70 		errno = ENAMETOOLONG;
71 		return(NULL);
72 	}
73 	(void)strncpy(bname, startp, endp - startp + 1);
74 	bname[endp - startp + 1] = '\0';
75 	return(bname);
76 }
77