move_dir

move_dir()： 这个函数将一个目录及其内容移动到服务器上的一个新位置。

将一个目录从一个位置移动到另一个位置。

成功时，递归地使OPcache失效。

如果重命名失败，则返回到copy_dir()。

假设WP_Filesystem()已经被调用和设置。

这个函数不是用来合并目录的，应该使用copy_dir()来代替。

function move_dir( $from, $to, $overwrite = false ) {
	global $wp_filesystem;

	if ( trailingslashit( strtolower( $from ) ) === trailingslashit( strtolower( $to ) ) ) {
		return new WP_Error( 'source_destination_same_move_dir', __( 'The source and destination are the same.' ) );
	}

	if ( $wp_filesystem->exists( $to ) ) {
		if ( ! $overwrite ) {
			return new WP_Error( 'destination_already_exists_move_dir', __( 'The destination folder already exists.' ), $to );
		} elseif ( ! $wp_filesystem->delete( $to, true ) ) {
			// Can't overwrite if the destination couldn't be deleted.
			return new WP_Error( 'destination_not_deleted_move_dir', __( 'The destination directory already exists and could not be removed.' ) );
		}
	}

	if ( $wp_filesystem->move( $from, $to ) ) {
		/*
		 * When using an environment with shared folders,
		 * there is a delay in updating the filesystem's cache.
		 *
		 * This is a known issue in environments with a VirtualBox provider.
		 *
		 * A 200ms delay gives time for the filesystem to update its cache,
		 * prevents "Operation not permitted", and "No such file or directory" warnings.
		 *
		 * This delay is used in other projects, including Composer.
		 * @link https://github.com/composer/composer/blob/2.5.1/src/Composer/Util/Platform.php#L228-L233
		 */
		usleep( 200000 );
		wp_opcache_invalidate_directory( $to );

		return true;
	}

	// Fall back to a recursive copy.
	if ( ! $wp_filesystem->is_dir( $to ) ) {
		if ( ! $wp_filesystem->mkdir( $to, FS_CHMOD_DIR ) ) {
			return new WP_Error( 'mkdir_failed_move_dir', __( 'Could not create directory.' ), $to );
		}
	}

	$result = copy_dir( $from, $to, array( basename( $to ) ) );

	// Clear the source directory.
	if ( true === $result ) {
		$wp_filesystem->delete( $from, true );
	}

	return $result;
}