php获取服务器地址

if ( isset( $_SERVER['HTTP_X_FORWARDED_HOST'] ) ) { // Support ProxyPass
        $t_hosts = explode( ',', $_SERVER['HTTP_X_FORWARDED_HOST'] );
        $t_host = $t_hosts[0];
    } else if ( isset( $_SERVER['HTTP_HOST'] ) ) {
        $t_host = $_SERVER['HTTP_HOST'];
    } else if ( isset( $_SERVER['SERVER_NAME'] ) ) {
        $t_host = $_SERVER['SERVER_NAME'] . $t_port;
    } else if ( isset( $_SERVER['SERVER_ADDR'] ) ) {
        $t_host = $_SERVER['SERVER_ADDR'] . $t_port;
    }