Serv-u web account application program written in PHP_PHP tutorial

//Sign.php
//The system is suitable for win2000
$path="e:\serv-u\ServUDaemon.ini";//The path of the user file
$fabu ="e:\web\";//Total web path
if($add)
{
$fp1=fopen($path,"r+");
$str=fread( $fp1, filesize($path));
$fp=fopen($path,"a");
flock($fp,3);
$us="=".$userid;
$start=strpos($str,$us);
if($start)
{
echo "Sorry, the user already exists";
}else{
$ start1=strpos($str,"User1");
if($start1){
$start=$start1+6;
$end=strpos($str,"|",$start) ;
$firstusername=substr($str,$start,$end-$start);
$start2=strpos($str,"[USER=".$firstusername."|1]");
$usernum=count(split("rn",substr($str,$start1,$start2-$start1)));
             }else
                                    }
$userinfo="User".$usernum."=".$userid."|1|0"."rn";
$userpath=$fabu.$userid;
@mkdir( $userpath,0700);
$maxsize=$size*1024;
$userp="[USER=".$userid."|1]"."rn";
$userp.=" Password=".$password."rn";
$userp.="HomeDir=".$userpath."rn";
$userp.="RelPaths=1"."rn";
$userp.="DiskQuota=1|".$maxsize."|0"."rn";
$userp.="MaxUsersLoginPerIP=2"."rn";
$userp.="TimeOut= 600"."rn";
$userp.="Access1=".$userpath."|RWAMLCDP"."rn";

if($start2){
$content=substr ($str,$start2,strlen($str)-$start2);
$content.=$userp;
$userinfo.=$content;
fseek($fp1,$start2,SEEK_SET) ;
fputs($fp1,$userinfo);
}else
                                           
//echo $firstusername;
//echo $start;
//echo "
";
//echo $end;


   }
fclose($fp);
fclose($fp1);
}
?>