perl + com port (SerialPort)

#!/usr/bin/perl -w
use Device::SerialPort;
my $port = Device::SerialPort->new("/dev/ttyUSB0");

# 19200, 81N on the USB ftdi driver
$port->user_msg(ON);
$port->baudrate(19200);
$port->databits(8);
$port->parity("none");
$port->stopbits(1);
$port->write("1");
while (1) {
    # Poll to see if any data is coming in
    my $char = $port->lookfor();

    # If we get data, then print it
    # Send a number to the arduino
    if ($char) {
        print "Received character: $char \n";
    }
}

pi@raspberrypi ~/m $ ./1
Received character:
PuTTY