PHP Obfuscator shutdown57

<?php
/**
 coded by shutdown57
**/
error_reporting(0);
$input=$argv[1];
$output=$argv[2];
echo "shutdown57 Obfuscator\n";
echo PHP_EOL;
if(empty($input) && empty($output))
{
    echo "Usage :: php $argv[0] original-file.php output.php \n";
    exit;
}
function strToHex($string){
 $field=bin2hex($string);
$field=chunk_split($field,2,"\x");
$field= "\x" . substr($field,0,-2);
return $field;
}
function RandomString()
{
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $randstring = '';
    for ($i = 0; $i <=5; $i++) {
        @$randstring.= $characters[rand(0, strlen($characters))];
    }
    return $randstring;
}

function obfuscate($text)
{
    $var = RandomString();
    $var2 = RandomString();

    $res = str_rot13(base64_encode($text));

    $content='$'.$var.'="\x73\x74\x72\x5f\x72\x6f\x74\x31\x33";$'.$var2.'="\x62\x61\x73\x65\x36\x34\x5f\x64\x65\x63\x6f\x64\x65";@eval($'.$var2.'($'.$var.'("'.$res.'")));';
    $hex=strToHex($content);
    return $content;
}

function create_result($result,$output)
{
    $var = "shutdown57_".RandomString();
    $content ='<?php /* Obfuscate by shutdown57 < indonesianpeople.shutdown57@gmail.com > */ ';
    $result = strToHex($result);
    $content.= '$'.$var.'="'.$result.'";@eval($'.$var.'); ?>';
    return file_put_contents($output,$content);
}
function cleanInput($text)
{
    $x=str_replace(['<?php','?>'],"",$text);
    return $x;
}
$input = cleanInput(file_get_contents($input));
$obs = obfuscate($input);
if(create_result($obs,$output))
{
    echo "DONE => $output \n";
}else{
    echo "FAILED !!\n";
}