1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Program that atomically exchanges two paths using
4  * the renameat2() system call RENAME_EXCHANGE flag.
5  *
6  * Copyright 2022 Red Hat Inc.
7  * Author: Javier Martinez Canillas <javierm@redhat.com>
8  */
9 
10 #define _GNU_SOURCE
11 #include <fcntl.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 
15 void print_usage(const char *program)
16 {
17 	printf("Usage: %s [oldpath] [newpath]\n", program);
18 	printf("Atomically exchange oldpath and newpath\n");
19 }
20 
21 int main(int argc, char *argv[])
22 {
23 	int ret;
24 
25 	if (argc != 3) {
26 		print_usage(argv[0]);
27 		exit(EXIT_FAILURE);
28 	}
29 
30 	ret = renameat2(AT_FDCWD, argv[1], AT_FDCWD, argv[2], RENAME_EXCHANGE);
31 	if (ret) {
32 		perror("rename exchange failed");
33 		exit(EXIT_FAILURE);
34 	}
35 
36 	exit(EXIT_SUCCESS);
37 }
38