php gets the complete URL address of the current page

<?php
/**
 * 获取当前页面完整URL地址
 */
function get_url() {
    $sys_protocal = isset($_SERVER[&#39;SERVER_PORT&#39;]) && $_SERVER[&#39;SERVER_PORT&#39;] == &#39;443&#39; ? &#39;https://&#39; : &#39;http://&#39;;
    $php_self = $_SERVER[&#39;PHP_SELF&#39;] ? $_SERVER[&#39;PHP_SELF&#39;] : $_SERVER[&#39;SCRIPT_NAME&#39;];
    $path_info = isset($_SERVER[&#39;PATH_INFO&#39;]) ? $_SERVER[&#39;PATH_INFO&#39;] : &#39;&#39;;
    $relate_url = isset($_SERVER[&#39;REQUEST_URI&#39;]) ? $_SERVER[&#39;REQUEST_URI&#39;] : $php_self.(isset($_SERVER[&#39;QUERY_STRING&#39;]) ? &#39;?&#39;.$_SERVER[&#39;QUERY_STRING&#39;] : $path_info);
    return $sys_protocal.(isset($_SERVER[&#39;HTTP_HOST&#39;]) ? $_SERVER[&#39;HTTP_HOST&#39;] : &#39;&#39;).$relate_url;
}
 
echo get_url();
?>