nfephp-org / posprint

            }

            sleep(1);

        }

        if ($this->handle === false) {

            $this->handle = null;

            $this->state = self::SERIAL_DEVICE_NOTSET;

            throw new RuntimeException('Fail to open device. Check permissions.');

        }

        stream_set_blocking($this->handle, false);

        $this->state = self::SERIAL_DEVICE_OPENED;

        return true;

        if ($this->state !== self::SERIAL_DEVICE_OPENED || ! is_resource($this->handle)) {

            return true;

        }

        if (fclose($this->handle)) {

            $this->handle = null;

            $this->state = self::SERIAL_DEVICE_SET;

            return true;

        }

        return false;

    }