local host and port number in Server variable

Question

I want to figure out getting the port number so the result might "turn" out correctly as expected.

$server_list = array(       
        "localhost:8282" => array("test" => FALSE, "site_id" => "flyToHeaven"),
);

$server_name = $_SERVER["SERVER_NAME"];
if (!isset($server_list[$server_name])) {
    $server_name = "unknown";
    print "unknown server name!!";
    exit();

I am getting "Unknown Server Name" in the output. Can someone please help me with this?