domain_exists( string $domain, string $path, int $network_id = 1 ): int|null

1552function domain_exists( $domain, $path, $network_id = 1 ) {1553	$path   = trailingslashit( $path );1554	$args   = array(1555		'network_id'             => $network_id,1556		'domain'                 => $domain,1557		'path'                   => $path,1558		'fields'                 => 'ids',1559		'number'                 => 1,1560		'update_site_meta_cache' => false,1561	);1562	$result = get_sites( $args );1563	$result = array_shift( $result );1564 1565	/**1566	 * Filters whether a site name is taken.1567	 *1568	 * The name is the site's subdomain or the site's subdirectory1569	 * path depending on the network settings.1570	 *1571	 * @since 3.5.01572	 *1573	 * @param int|null $result     The site ID if the site name exists, null otherwise.1574	 * @param string   $domain     Domain to be checked.1575	 * @param string   $path       Path to be checked.1576	 * @param int      $network_id Network ID. Only relevant on multi-network installations.1577	 */1578	return apply_filters( 'domain_exists', $result, $domain, $path, $network_id );1579}