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