get_id_from_blogname( string $slug ): int|null

86function get_id_from_blogname( $slug ) {87	$current_network = get_network();88	$slug            = trim( $slug, '/' );89 90	if ( is_subdomain_install() ) {91		$domain = $slug . '.' . preg_replace( '|^www\.|', '', $current_network->domain );92		$path   = $current_network->path;93	} else {94		$domain = $current_network->domain;95		$path   = $current_network->path . $slug . '/';96	}97 98	$site_ids = get_sites(99		array(100			'number'                 => 1,101			'fields'                 => 'ids',102			'domain'                 => $domain,103			'path'                   => $path,104			'update_site_meta_cache' => false,105		)106	);107 108	if ( empty( $site_ids ) ) {109		return null;110	}111 112	return array_shift( $site_ids );113}