[PHP-TEST] HEX2BIN

function convertHexToSym($str) // Converter from HEX to Symbols
// Ex.: 48656C6C6F2C20776F726C6421 -> Hello, world!
{
    $len_str = strlen($str);
    $array = array();
    $edit = substr($str, 0);
    for ($i = 2; $i <= $len_str ; $i += 2) {
        $n = sscanf($edit, "%02X", $val);
        if ($n > 0) {
            $buf = sprintf("%c", $val);
            $array[$i] = $buf;
            $edit = substr($str, $i);
        }
    }
    $out = implode("", $array);
    return $out;
}