xref: /freebsd/lib/libc/gen/basename.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 /*	$OpenBSD: basename.c,v 1.14 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 #include <sys/cdefs.h>
20 __FBSDID("$FreeBSD$");
21 
22 #include <errno.h>
23 #include <libgen.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/param.h>
27 
28 char *
29 basename_r(const char *path, char *bname)
30 {
31 	const char *endp, *startp;
32 	size_t len;
33 
34 	/* Empty or NULL string gets treated as "." */
35 	if (path == NULL || *path == '\0') {
36 		bname[0] = '.';
37 		bname[1] = '\0';
38 		return (bname);
39 	}
40 
41 	/* Strip any trailing slashes */
42 	endp = path + strlen(path) - 1;
43 	while (endp > path && *endp == '/')
44 		endp--;
45 
46 	/* All slashes becomes "/" */
47 	if (endp == path && *endp == '/') {
48 		bname[0] = '/';
49 		bname[1] = '\0';
50 		return (bname);
51 	}
52 
53 	/* Find the start of the base */
54 	startp = endp;
55 	while (startp > path && *(startp - 1) != '/')
56 		startp--;
57 
58 	len = endp - startp + 1;
59 	if (len >= MAXPATHLEN) {
60 		errno = ENAMETOOLONG;
61 		return (NULL);
62 	}
63 	memcpy(bname, startp, len);
64 	bname[len] = '\0';
65 	return (bname);
66 }
67 
68 char *
69 basename(const char *path)
70 {
71 	static char *bname = NULL;
72 
73 	if (bname == NULL) {
74 		bname = (char *)malloc(MAXPATHLEN);
75 		if (bname == NULL)
76 			return (NULL);
77 	}
78 	return (basename_r(path, bname));
79 }
80