queryPMMPServer.php

<?php

const WRAPPER = "\xfe\xfd";
const SESSIONID = "\x01\x02\x03\x04";
const HANDSHAKE = "\x09";
const STATISTICS = "\x00";

function queryPMMPServer(string $ip, int $port = 19132): array {
	$socket = fsockopen("udp://" . gethostbyname($ip), $port, $errno, $errstr);

	$handshake = WRAPPER . HANDSHAKE . SESSIONID; //wrapper + handshake + sessionid
	fwrite($socket, $handshake, strlen($handshake));

	$handshake_reply = fread($socket, 4096); //handshake + sessionid + token + \x00
	$token = substr($handshake_reply, 5, -1);

	$statistics = WRAPPER . STATISTICS . SESSIONID . pack("N", $token) . str_repeat("\x00", 4); //wrapper + statistics + sessionid + token from handshake + 4 bytes for long query (if omitted the server will return short query)
	fwrite($socket, $statistics, strlen($statistics));

	$statistics_reply = fread($socket, 4096); //info (key + \x00 + value + \x00) + \x00\x01player_\x00\x00 + player list (player + \x00) + \x00

	$query = explode("\x00\x00\x01player_\x00\x00", substr($statistics_reply, 16, -1));

	$data = $query[0];
	$n = 0;
	$info = [];
	foreach (explode("\x00", $data) as $key_value) {
		if ($n % 2 == 0) {
			$key = $key_value;
		}else {
			$info[$key] = $key_value;
		}
		$n++;
	}

	$players = $query[1];
	if ($players == "") {
		$players = [];
	}else {
		$players = substr($players, 0, -1);
		$players = explode("\x00", $players);
	}

	fclose($socket);
	return ["info" => $info, "players" => $players];
}

/*      -------- TEST --------      */

$result = queryPMMPServer("play.moonforce.eu", 19132);
$info = $result["info"];
$players = $result["players"];
foreach ($info as $key => $value) {
	echo $key . ": " . $value . PHP_EOL;
}
echo "players: " . implode(", ", $players) . PHP_EOL;