Turn screen on/off if one of the specified machines is online.

screen.sh

#!/usr/bin/php
<?php

$hosts = array(
	"192.168.10.11",
	"192.168.10.12",
	"192.168.10.13",
	"192.168.10.14",
	"192.168.10.15",
	"192.168.10.16",
	"192.168.10.17",
	"192.168.10.18",
	"192.168.10.19",
);

$online = false;
foreach($hosts as $host)
{
	$result = shell_exec("ping -c 1 -W 1 " . $host);
	if(strstr($result, "1 received"))
	{
		$online = true;
		break;
	}
}

if($online)
{
	exec("xset dpms force on; xset s reset");
}
else
{
	exec("xset dpms force off");
}