UUID Generator

function struuid($entropy)
{
    $s=uniqid("",$entropy);
    $num= hexdec(str_replace(".","",(string)$s));
    $index = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
    $base= strlen($index);
    $out = '';
        for($t = floor(log10($num) / log10($base)); $t >= 0; $t--) {
            $a = floor($num / pow($base,$t));
            $out = $out.substr($index,$a,1);
            $num = $num-($a*pow($base,$t));
        }
    return $out;
}

echo struuid(false); //Return sample: P3YCAU6EY2
echo struuid(true);  //Return sample: N5YQLFG922EFW7JDE