PHP Simple Stats v2

gistfile1.php

<?php

class SimpleStats {
	private $url		= 'http://localhost/';
	private $lock		= '.stats.lock';
	private $network	= 'lo';
	private $response	= '/Unable to locate domain/';
	private $procs		= array(
		'/usr/sbin/mysqld',
		'/usr/sbin/lighttpd',
		'/usr/sbin/php5-fpm'
	);

	public function __construct(){
		if(is_file($this->lock)) die('Stats are locked with ' . $this->lock);
	}

	private function Set($i, $v=false){
		$this->$i=$v;
	}

	private function Net($t, $s=1){
		$a = trim(file_get_contents('/sys/class/net/'.$this->network.'/statistics/'.$t.'_bytes'));
		sleep($s);
		$b = trim(file_get_contents('/sys/class/net/'.$this->network.'/statistics/'.$t.'_bytes'));
		return round((($b - $a) / $s) / 1024, 2) ;
	}

	private function Pidof($p){
		return trim(exec('pidof '.$p));
	}

	private function Procs(){
		foreach($this->procs as $proc){
			if(!$this->Pidof($proc)) return false;
		}
		return true;
	}

	private function Load(){
		return sys_getloadavg();
	}

	public function run(){
		return array(
			'memory'		=> round(exec("printf \$(free -m| grep  Mem | awk '{ print \$3/\$2*100 }')"),2),
			'disc'			=> (100-round(disk_free_space(getcwd())/disk_total_space (getcwd()) * 100,2)),
			'cpu'			=> round(exec("grep 'cpu ' /proc/stat | awk '{c=($2+$4)*100/($2+$4+$5)} END {print c}'"),2),
			'load'			=> $this->Load()[0],
			'net_out'		=> $this->Net('tx'),
			'net_in'		=> $this->Net('rx'),
			'connections'	=> exec("netstat -nt | awk '{ print $5}' | cut -d: -f1 | sed -e '/^$/d' | sort -n | uniq | wc -l"),
			'running'		=> $this->Procs(),
			'available'		=> (preg_match($this->response, file_get_contents($this->url)) ? true : false)
		);
	}

	public function __destroy(){
		if(is_file($this->lock)) unlink($this->lock);
	}
}

$SimpleStats=new SimpleStats();
die(json_encode($SimpleStats->run()));