PHP anti-attack code upgraded version_PHP tutorial

/*
*Anti-IP attack code website)2010-11-20,Ver2.0
*Mydalle.com Anti-refresh mechanism
*design by www.mydalle .com
*/
//Query banned IP
$ip =$_SERVER['REMOTE_ADDR'];
$fileht=".htaccess2";
if(!file_exists($fileht))file_put_contents($fileht,"");
$filehtarr=@file($fileht);
if(in_array($ip."rn",$filehtarr))die ("Warning:"."
"."Your IP address are forbided by Mydalle.com Anti-refresh mechanism, IF you have any question Pls emill to shop@mydalle.com!
(Mydalle.com Anti-refresh mechanism is to enable users to have a good shipping services, but there maybe some inevitable network problems in your IP address, so that you can mail to us to solve.)");


//Add banned IP
$time=time();
$fileforbid="log/forbidchk.dat";

if(file_exists($fileforbid))
{ if($ time-filemtime($fileforbid)>30)unlink($fileforbid);
else{
$fileforbidarr=@file($fileforbid);
if($ip==substr($fileforbidarr[0 ],0,strlen($ip)))
{
if($time-substr($fileforbidarr[1],0,strlen($time))>120)unlink($fileforbid);
elseif($fileforbidarr[2]>120){file_put_contents($fileht,$ip."rn",FILE_APPEND);unlink($fileforbid);}
else{$fileforbidarr[2]++;file_put_contents ($fileforbid,$fileforbidarr);}
}
}
}

//Anti-refresh
$str="";
$file="log/ipdate .dat";
if(!file_exists("log")&&!is_dir("log"))mkdir("log",0777);
if(!file_exists($file))file_put_contents($file ,"");
$allowTime = 60;//Anti-refresh time
$allowNum=5;//Number of anti-refresh times
$uri=$_SERVER['REQUEST_URI'];
$checkip =md5($ip);
$checkuri=md5($uri);
$yesno=true;
$ipdate=@file($file);
foreach($ipdate as $k =>$v)
{ $iptem=substr($v,0,32);
$uritem=substr($v,32,32);
$timetem=substr($v, 64,10);
$numtem=substr($v,74);
if($time-$timetem<$allowTime){
if($iptem!=$checkip)$str.= $v;
else{
$yesno=false;
if($uritem!=$checkuri)$str.=$iptem.$checkuri.$time."1rn";
elseif( $numtem<$allowNum)$str.=$iptem.$uritem.$timetem.($numtem+1)."rn";
else
{
if(!file_exists($fileforbid)) {$addforbidarr=array($ip."rn",time()."rn",1);file_put_contents($fileforbid,$addforbidarr);}
file_put_contents("log/forbided_ip.log",$ip. "--".date("Y-m-d H:i:s",time())."--".$uri."rn",FILE_APPEND);
$timepass=$timetem+$allowTime-$time;
die("Warning:"."
"."Pls don't refresh too frequently, and wait for ".$timepass." seconds to continue, IF not your IP address will be forbided automatically by Mydalle .com Anti-refresh mechanism!
(Mydalle.com Anti-refresh mechanism is to enable users to have a good shipping services, but there maybe some inevitable network problems in your IP address, so that you can mail to us to solve.)");
}
}
}
}
if($yesno) $str.=$checkip.$checkuri.$time."1rn";
file_put_contents($file,$str);
?>