get_search_link( string $query = '' )

function get_search_link( $query = '' ) {
	global $wp_rewrite;

	if ( empty($query) )
		$search = get_search_query( false );
	else
		$search = stripslashes($query);

	$permastruct = $wp_rewrite->get_search_permastruct();

	if ( empty( $permastruct ) ) {
		$link = home_url('?s=' . urlencode($search) );
	} else {
		$search = urlencode($search);
		$search = str_replace('%2F', '/', $search); // %2F(/) is not valid within a URL, send it un-encoded.
		$link = str_replace( '%search%', $search, $permastruct );
		$link = home_url( user_trailingslashit( $link, 'search' ) );
	}

	/**
	 * Filters the search permalink.
	 *
	 * @since WP-3.0.0
	 *
	 * @param string $link   Search permalink.
	 * @param string $search The URL-encoded search term.
	 */
	return apply_filters( 'search_link', $link, $search );
}