PHP simple method to count the number of people online_php skills

<?php
//首先你要有读写文件的权限
//本程序可以直接运行,第一次报错,以缶涂梢?
$online_log = "count.dat"; //保存人数的文件,
$timeout = 30;//30秒内没动作者,认为掉线
$entries = file($online_log);
$temp = array();
for ($i=0;$i<count($entries);$i++) {
 $entry = explode(",",trim($entries[$i]));
 if (($entry[0] != getenv('remote_addr')) && ($entry[1] > time())) {
  array_push($temp,$entry[0].",".$entry[1]."\n"); //取出其他浏览者的信息,并去掉超时者,保存进$temp
 }
}
array_push($temp,getenv('remote_addr').",".(time() + ($timeout))."\n"); //更新浏览者的时间
$users_online = count($temp); //计算在线人数
$entries = implode("",$temp);
//写入文件
$fp = fopen($online_log,"w");
flock($fp,lock_ex); //flock() 不能在nfs以及其他的一些网络文件系统中正常工作
fputs($fp,$entries);
flock($fp,lock_un);
fclose($fp);
echo "当前有".$users_online."人在线";
?>

include("count.php");