获取当前的url地址

/**
 * 获取当前的url 地址
 * @return type
 */
function get_url_openid()
{
    $sys_protocal = isset($_SERVER['SERVER_PORT']) && $_SERVER['SERVER_PORT'] == '443' ? 'https://' : 'http://';
    $php_self = $_SERVER['PHP_SELF'] ? $_SERVER['PHP_SELF'] : $_SERVER['SCRIPT_NAME'];
    $path_info = isset($_SERVER['PATH_INFO']) ? $_SERVER['PATH_INFO'] : '';
    $relate_url = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : $php_self . (isset($_SERVER['QUERY_STRING']) ? '?' . $_SERVER['QUERY_STRING'] : $path_info);
    return $sys_protocal . (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST'] : '') . $relate_url;
}