A simple script for getting and displaying server stats in StatusBoard

statusboard-serverstats.php

<?php

//add your server aliases here
$servers = array(
	"185.14.184.234" => "mcfly.bensmann.no",
	"185.14.184.xxx" => "another.server.com",
);

//this script is triggered by this command from the terminal or cron:
//echo "time=`uptime`&df=`df -h`" | curl -s -d @- http://domain.com/path/to/script.php

//record data
if(isset( $_POST['time'], $_POST['df'] )){
	//getting the server load
	preg_match('/\d+\.\d{2}/', $_POST['time'],$load);
	
	//get available disk space
	preg_match('/\d+%/', $_POST['df'],$df);
	
	if(!count($load) || !count($df))
		return false;
	
	$stats = array(
		"df" => $df[0],
		"load" => $load[0],
		"ip" => $_SERVER["REMOTE_ADDR"]
	);
	
	save_to_stats($stats);
}else{
	output_stats_table();
}

function save_to_stats($stats){
	$data = json_decode( file_get_contents("stats.json"), true );
	$data[  $stats['ip'] ] = $stats;
	file_put_contents("stats.json", json_encode($data), LOCK_EX);
}

function output_stats_table(){
	global $servers;
	//display data
	$data = json_decode( file_get_contents("stats.json"), true );

	?>
	<table id="projects">
		<?php foreach($data as $server => $stats): ?> 
			<tr>
				<td class="server-name" style="width:400px; text-transform:lowercase;"><?php echo $servers[$stats['ip']] ; ?></td>
				<td class="server-disk-space"><?php echo $stats['load']; ?></td>
				<td class="projectsBars">
				
					<?php for( $i = 1, $j = number_of_bars($stats['df']); $i <= $j; $i++ ): ?>
						<div class="barSegment value<?php echo $i; ?>"></div>
					<?php endfor; ?>
				
				</td>
			</tr>
		<?php endforeach; ?> 
	</table>

	<?php
};

function number_of_bars($df){
	$value = (int) str_replace('%', '', $df) / 10;
	return round( ($value > 8 ? 8 : $value) * .8 );
}

I'm also struggling with this script. I can't seem to get my stats.json file populated. I don't experience any errors when I run the command from terminal to echo the server status...but when I land on the script page all I see is a blank white screen. Any suggestions? I'm super excited to get this up and running! Thank you!

Not working here either, Debian squeeze. Even chmod 777 dir+files. Can only see the load.
stats.json gives me this:

{"98.22.33.11":{"df":"0%","load":"0.05","ip":"98.22.33.11"}