xref: /freebsd/contrib/bmake/dirname.c (revision b740c88bfb6453416926271c089262e7164dace3)
1 /*	$NetBSD: dirname.c,v 1.11 2009/11/24 13:34:20 tnozaki 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 #ifdef HAVE_CONFIG_H
33 # include <config.h>
34 #endif
35 #ifndef HAVE_DIRNAME
36 
37 #include <sys/cdefs.h>
38 
39 #ifdef HAVE_LIMITS_H
40 #include <limits.h>
41 #endif
42 #ifdef HAVE_STRING_H
43 #include <string.h>
44 #endif
45 #ifndef PATH_MAX
46 # define PATH_MAX 1024
47 #endif
48 
49 char *
50 dirname(char *path)
51 {
52 	static char result[PATH_MAX];
53 	const char *lastp;
54 	size_t len;
55 
56 	/*
57 	 * If `path' is a null pointer or points to an empty string,
58 	 * return a pointer to the string ".".
59 	 */
60 	if ((path == NULL) || (*path == '\0'))
61 		goto singledot;
62 
63 
64 	/* Strip trailing slashes, if any. */
65 	lastp = path + strlen(path) - 1;
66 	while (lastp != path && *lastp == '/')
67 		lastp--;
68 
69 	/* Terminate path at the last occurence of '/'. */
70 	do {
71 		if (*lastp == '/') {
72 			/* Strip trailing slashes, if any. */
73 			while (lastp != path && *lastp == '/')
74 				lastp--;
75 
76 			/* ...and copy the result into the result buffer. */
77 			len = (lastp - path) + 1 /* last char */;
78 			if (len > (PATH_MAX - 1))
79 				len = PATH_MAX - 1;
80 
81 			memcpy(result, path, len);
82 			result[len] = '\0';
83 
84 			return (result);
85 		}
86 	} while (--lastp >= path);
87 
88 	/* No /'s found, return a pointer to the string ".". */
89 singledot:
90 	result[0] = '.';
91 	result[1] = '\0';
92 
93 	return (result);
94 }
95 #endif
96