Shouldn't you make the stream non-blocking? Try adding this after fsockopen:

stream_set_blocking($fp, false);

It still hangs:

$fp = fsockopen("udp://".$ip,$port, $errno, $errstr);
stream_set_blocking($fp, 0);

Well, can you give a script that has some possibility of working properly? In the give script you have at least one variable which is not set anywhere: $komut

i gave $tanim in function use:

function rcon_komut($komut, $rcon_pass, $ip, $port)
{
	$msg = "????challenge rcon";
    	$fp = fsockopen("udp://".$ip,$port, $errno, $errstr);
		
	stream_set_blocking($fp, 0);
		
    	fputs($fp, $msg, strlen($msg));
	$response = fgets($fp, 1024);    			
	$challenge = substr($response, 19, strlen($response) - 20);
		
	$msg="????rcon".$challenge."\"".$rcon_pass."\"".$komut.chr(0);
	fputs($fp, $msg, strlen($msg));
		
	while (!feof($fp))
		$response .= fgets($fp, 32);

    	fclose ($fp);
	$response = substr($response, 6, strlen($response)-6);
	return $response;
}

That's still just a piece of the script, a proper test script starts with <?php and ends in ?> and can be just copy'pasted and run..

Here is the full program:

<?php

echo rcon_komut("meta list", "123456", "62.68.207.16", 27015);

function rcon_komut($komut, $rcon_pass, $ip, $port)
{
	$response = "";
	$msg = "????challenge rcon";
    	$fp = fsockopen("udp://".$ip,$port, $errno, $errstr);
		
	stream_set_blocking($fp, 0);
		
    	fputs($fp, $msg, strlen($msg));
	$response = fgets($fp, 1024);    			
	$challenge = substr($response, 19, strlen($response) - 20);
		
	$msg="????rcon".$challenge."\"".$rcon_pass."\"".$komut.chr(0);
	fputs($fp, $msg, strlen($msg));
		
	while (!feof($fp))
		$response .= fgets($fp, 4096);

    	fclose ($fp);

	return $response;
}

?>

Your script doesn't work because you don't get anything in $response in the first place. So you're passing invalid data around long before feof() is used and the server just sits there propably waiting for more data to be input before it gives any back..

actually if i set stream_set_blocking for $fp to 1 it gives the result (which i posted the code below) if i change stream_set_blocking to 0, it does not give any result. in either ways if i use feof($fp) it hangs..

<?php

echo rcon_komut("meta list", "123456", "62.68.207.16", 27015);

function rcon_komut($komut, $rcon_pass, $ip, $port)
{
        $response = "";
        $msg = "????challenge rcon";
        $fp = fsockopen("udp://".$ip,$port, $errno, $errstr);

        stream_set_blocking($fp, 1);

        fputs($fp, $msg, strlen($msg));

        $response .= fgets($fp, 1024);

        fclose ($fp);

        return $response;
}

?>

Your script was buggy, this works:

<?php

echo rcon_komut("meta list", "123456", "62.68.207.16", 27015);

function rcon_komut($komut, $rcon_pass, $ip, $port)
{
  $fp = fsockopen("udp://".$ip,$port, $errno, $errstr);
  socket_set_timeout($fp, 3);

  $prefix = "\xff\xff\xff\xff";
  $msg = "{$prefix}challenge rcon\n";
  fputs($fp, $msg, strlen($msg));

  $response = fgets($fp, 1024);    
  $challenge = substr($response, 19, strlen($response) - 20);

  $msg = "\xff\xff\xff\xffrcon $challenge \"$rcon_pass\" $komut\n";
  fputs($fp, $msg, strlen($msg));

  $status = socket_get_status($fp);

  while($status['unread_bytes']) {
    $response .= fgets($fp, 2048);
    $status = socket_get_status($fp);
  }
  fclose ($fp);
  return $response;
}
?>

Using feof() makes no sense with udp streams..