Packet struckt in php?

Hello,
I am trying to do a bit of testing with php sockets, but the program that is supposed to recive the packets expects them to come in as structures. Is there any way to create them under php? An example of the structure is:

Code:

struct InSimInit
{
	char	Id	[4];	
	word	Port;		
	byte	Flags;		
	byte	NodeSecs;	
	char	Admin	[16];
};

Another question i have is that there is an example of a udp connection on the php.net site:

The example below shows how to retrieve the day and time from the UDP service "daytime" (port 13) in your own machine. Example 2. Using UDP connection.

PHP:

<?php
$fp = fsockopen("udp://127.0.0.1", 13, $errno, $errstr);
if (!$fp) {
   echo "ERROR: $errno - $errstr<br />\n";
} else {
   fwrite($fp, "\n");
   echo fread($fp, 26);
   fclose($fp);
}
?> 


But it doesn't seem to do anything?