1# make sure every subprocess has it's exit and that the main one
2# hasn't
3sub fun {
4    unless ($pid = fork) {
5        unless (fork) {
6            use Tk;
7            $MW = MainWindow->new;
8            $hello = $MW->Button(
9                -text    => 'Hello, world',
10                -command => sub {exit;},
11            );
12            $hello->pack;
13            MainLoop;
14        }
15        exit 0;
16    }
17    waitpid($pid, 0);
18}
19
201;
21