PHP get the full URL address

/**
 * 获取当前完整URL
 * @return string
 */
function get_url()
{
    $sys_protocal = isset($_SERVER['SERVER_PORT']) && $_SERVER['SERVER_PORT'] == '443' ? 'https://' : 'http://'; //根据当前端口，判断是http还是https
    $php_self = $_SERVER['PHP_SELF'] ? $_SERVER['PHP_SELF'] : $_SERVER['SCRIPT_NAME']; //获取当前网页地址
    $path_info = isset($_SERVER['PATH_INFO']) ? $_SERVER['PATH_INFO'] : ''; //获取path_info信息
    $relate_url = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : $php_self . (isset($_SERVER['QUERY_STRING']) ? '?' . $_SERVER['QUERY_STRING'] : $path_info); //获取除域名外的完整URL,获取不到php文件（如启用了pathinfo)，就获取文件实际地址和参数
    $url = $sys_protocal . (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : '') . $relate_url;
    
    return  $url;
    // 打印到日志
    $msg = PHP_EOL . date("Y-m-d H:i:s") . " " . $url;
    file_put_contents('./log.txt', $msg, FILE_APPEND | LOCK_EX);
}

$this->get_url();