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
15void print_usage(const char *program)
16{
17	printf("Usage: %s [oldpath] [newpath]\n", program);
18	printf("Atomically exchange oldpath and newpath\n");
19}
20
21int 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}