use Tk;
use IO::Socket;

my $status = '';

my $mw = MainWindow->new;
$mw->geometry("200x200");
my $buttonFrame = $mw->Frame()->pack(-side => 'bottom');
$buttonFrame->Button(-text => 'Start',
                   -command => sub { init_server(\$mw, \$status) }
    )->pack(-side => 'left');

my $displayFrame = $mw->Frame()->pack(-side => 'top');
$displayFrame->Label(-text => 'Status:')->pack(-side => 'left');
$displayFrame->Label(-textvariable => \$status)->pack(-side => 'left');

MainLoop;

sub init_server {
    my ($mw_ref, $status_ref) = @_;

    my $server = IO::Socket::INET::->new(
        Proto     => 'tcp',
        LocalPort => 55555,
        Listen    => 1,
        Reuse     => 1
    ) or die "Server can't start: $!";
    my $client = $server->accept();
    $client->autoflush;

    $$mw_ref->fileevent($client, 'readable', sub {
        if (defined(my $read = <$client>)) {
            chomp $read;
            $$status_ref = $read;
        }
    });
}