$str = \'test\';
$cm = md5($str);
$bm = md5($str, true);

$cstr = implode(unpack(\'H*\', $bm));
$bstr = pack(\'H*\', $cm);

echo \'str:\'. $str . \"<br >\\n\";
echo \'cm :\' . $cm . \"<br >\\n\";
echo \'cstr:\' . $cstr . \"<br >\\n\";
echo \'urlencode(bm)  :\' . urlencode($bm) . \"<br >\\n\";
echo \'urlencode(bstr):\' . urlencode($bstr) . \"<br >\\n\";