<?
$OnlineFile='online.txt';
$TimeoutOnlineMinutes = 10;

$fdOn = @fopen( $OnlineFile, 'a+' );
$fdip = $_SERVER['REMOTE_ADDR'];
$onlinenow[$fdip]=1;
while( !@feof($fdOn) ){
$cbr = explode('^',@fgets( $fdOn, 4096 ));
if($cbr[0] == $fdip){$noinput=1; $onlinenow[$fdip]++; }
if($cbr[1] > time()-($TimeoutOnlineMinutes*60))$onlinenow[$cbr[0]]++;
}
if(!$noinput)@fputs($fdOn,"$ip^".time()."^\n");
@fclose($fdOn);
$Online_Guests = count($onlinenow);
echo $Online_Guests;
?>