// list serial devicesSerialIO.list() @=> string list[];// no serial devices availableif( list.size() == 0 ){    cherr <= "no serial devices available\n";    me.exit(); }// print list of serial deviceschout <= "available devices\n";for( int i; i < list.size(); i++ ){    chout <= i <= ": " <= list[i] <= IO.newline();} // parse first argument as device number0 => int device;if( me.args() ) me.arg(0) => Std.atoi => device; if( device >= list.size() ){    cherr <= "serial device #" <= device <= "not available\n";    me.exit(); } // open serial deviceSerialIO cereal;if( !cereal.open(device, SerialIO.B9600, SerialIO.ASCII) ){    chout <= "unable to open serial device '" <= list[device] <= "'\n";    me.exit();} // pause to let serial device finish opening2::second => now; // infinite time-loopwhile( true ){    // write to serial device    cereal <= "hi!\n";    chout <= "<= hi!\n";        // read one line    cereal.onLine() => now;    chout <= "=> " <= cereal.getLine() <= IO.nl();        // advance time    1::second => now;}