public function confCharacterLength($int)
    {
        if ($this->_dState !== SERIAL_DEVICE_SET) {
            trigger_error("Unable to set length of a character : the device " .
                          "is either not set or opened", E_USER_WARNING);

            return false;
        }

        $int = (int) $int;
        if ($int < 5) {
            $int = 5;
        } elseif ($int > 8) {
            $int = 8;
        }

        if ($this->_os === "linux") {
            $ret = $this->_exec(
                "stty -F " . $this->_device . " cs" . $int,
                $out
            );
        } elseif ($this->_os === "osx") {
            $ret = $this->_exec(
                "stty -f " . $this->_device . " cs" . $int,
                $out
            );
        } else {
            $ret = $this->_exec(
                "mode " . $this->_winDevice . " DATA=" . $int,
                $out
            );
        }

        if ($ret === 0) {
            return true;
        }

        trigger_error(
            "Unable to set character length : " .$out[1],
            E_USER_WARNING
        );

        return false;
    }