#!/usr/bin/env perl

use warnings;
use strict;

#
# Scan all USB devices to find the Model 01's modem device number.
#
my @output = qx(/usr/sbin/usbconfig show_ifdrv);
my $serial_port_number;

foreach my $line (@output) {
  chomp $line;

  next unless $line =~ m/umodem(\d+):.*Keyboardio Model 01/;
  $serial_port_number = $1;
}

die "Can't find Model 01" unless defined($serial_port_number);

my $serial_port_name = "/dev/cuaU$serial_port_number";
die "Missing serial port at $serial_port_name" unless -e $serial_port_name;
print "$serial_port_name\n";
exit 0;