Последняя PHP функция

<?php // (c) by SPunk 31.12.2010 =)
function convers_size($size = 0) {
  $convers_size = array("Bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB");
  return $size ? round($size/pow(1024, ($i = floor(log($size, 1024)))), 2) . ' ' . $convers_size[$i] : ' 0 ' . $convers_size[0];
}?>

<?php
function _gen() {

$salt = str_split('aAbBcCdDeEfFgGhHijJkKLmMnNopPqQrRsStTuUvVwWxXyYzZ123456789');
$makepass = '';

for ($i = 0; $i < 6; ++$i) {

$rand = rand(0, count($salt) - 1);
$symbol = $salt[$rand];

if (!is_int($symbol)) {
unset($salt[$rand]);
$salt = array_values($salt);
}

$makepass .= $symbol;
}

if (!preg_match('/[a-z]{1,}/', $makepass) || !preg_match('/[A-Z]{1,}/', $makepass) || !preg_match('/[0-9]{1,}/', $makepass)) return _gen();

return $makepass;

}
?>

<?
function _gen()
{
 Return substr(str_shuffle('qwertyuiopasdfghjklzxcvbnmQXCVBNM123456789'), 0, 6);
}
?>