1/*	$NetBSD: basename.c,v 1.12 2023/01/18 08:07:22 simonb Exp $	*/
2
3/*-
4 * Copyright (c) 1997, 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Klaus Klein and Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34__RCSID("$NetBSD: basename.c,v 1.12 2023/01/18 08:07:22 simonb Exp $");
35#endif /* !LIBC_SCCS && !lint */
36
37#include "namespace.h"
38#include <sys/param.h>
39#include <libgen.h>
40#include <string.h>
41#include <limits.h>
42#include <string.h>
43
44#ifdef __weak_alias
45__weak_alias(basename,_basename)
46#endif
47
48static size_t
49xbasename_r(const char *path, char *buf, size_t buflen)
50{
51	const char *startp, *endp;
52	size_t len;
53
54	/*
55	 * If `path' is a null pointer or points to an empty string,
56	 * return a pointer to the string ".".
57	 */
58	if (path == NULL || *path == '\0') {
59		startp = ".";
60		len = 1;
61		goto out;
62	}
63
64	/* Strip trailing slashes, if any. */
65	endp = path + strlen(path) - 1;
66	while (endp != path && *endp == '/')
67		endp--;
68
69	/* Only slashes -> "/" */
70	if (endp == path && *endp == '/') {
71		startp = "/";
72		len = 1;
73		goto out;
74	}
75
76	/* Now find the beginning of this (final) component. */
77	for (startp = endp; startp > path && *(startp - 1) != '/'; startp--)
78		continue;
79
80	/* ...and copy the result into the result buffer. */
81	len = (endp - startp) + 1 /* last char */;
82out:
83	if (buf != NULL && buflen != 0) {
84		buflen = MIN(len, buflen - 1);
85		memcpy(buf, startp, buflen);
86		buf[buflen] = '\0';
87	}
88	return len;
89}
90
91#if !HAVE_BASENAME
92
93char *
94basename(char *path)
95{
96	static char result[PATH_MAX];
97
98	(void)xbasename_r(path, result, sizeof(result));
99	return result;
100}
101
102#endif
103