1 /*-
2  * Copyright (c) 2012 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Pawel Jakub Dawidek under sponsorship from
6  * the FreeBSD Foundation.
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  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef	_RENAMEAT_H_
31 #define	_RENAMEAT_H_
32 
33 #include <stdio.h>
34 #include <unistd.h>
35 
36 static int
37 renameat(int fromfd, const char *from, int tofd, const char *to)
38 {
39 	int cfd, error, ret;
40 
41 	if (fromfd != tofd) {
42 		errno = EINVAL;
43 		return (-1);
44 	}
45 
46 	cfd = open(".", O_RDONLY | O_DIRECTORY);
47 	if (cfd == -1)
48 		return (-1);
49 
50 	if (fchdir(fromfd) == -1) {
51 		error = errno;
52 		(void)close(cfd);
53 		errno = error;
54 		return (-1);
55 	}
56 
57 	ret = rename(from, to);
58 
59 	error = errno;
60 	(void)fchdir(cfd);
61 	(void)close(cfd);
62 	errno = error;
63 	return (ret);
64 }
65 
66 #endif	/* !_RENAMEAT_H_ */
67