PHP crypt command line

crypt

#!/usr/bin/php
< ?php
require "crypt.php";

$type = $argv['1'];
$string = $argv['2'];
$key = $argv['3'];
if($type !='' &&  $string != '' && $key != ''){
        if($type=="e"){
                echo encrypt($string,$key);
                echo "\n";
        }
        elseif($type=="d")
        {
                echo decrypt($string,$key);
                echo "\n";
        }
        else
        {
                die('WRONG TYPE');
        }
}
else
{
        echo 'crypt TYPE STRING KEY';
        echo "\n\n";
        echo "TYPE:\n";
        echo "e encrypt\n";
        echo "d decrypt\n";
        echo "\n\n";
        echo "STRING Your string\n";
        echo "KEY Crypt key\n\n";
}
?>

crypt.php

< ?php
/**
 * encrypt()
 *
 * @param mixed $string
 * @param mixed $key
 * @return mixed $retrun
 */
function encrypt($string, $key){

        $result = '';
        $lentgh = strlen($string);
        for($i = 0; $i < $lentgh; $i++) {
                $char = substr($string, $i, 1);
                $keychar = substr($key, ($i % strlen($key))-1, 1);
                $char = chr(ord($char) + ord($keychar));
                $result .= $char;
        }

        return base64_encode($result);
}

/**
 * decrypt()
 *
 * @param mixed $string
 * @param mixed $key
 * @return mixed $return
 */
function decrypt($string, $key){

        $result = '';
        $string = base64_decode($string);
        $lentgh = strlen($string);

        for($i = 0; $i < $lentgh; $i++) {
                $char = substr($string, $i, 1);
                $keychar = substr($key, ($i % strlen($key))-1, 1);
                $char = chr(ord($char) - ord($keychar));
                $result .= $char;
        }

        return $result;
}
?>