Have you tried using fileevent? Something along these lines works for me (though with Attempt to free unreferenced scalar at the end): 
open $STDIN,'-';

$top->fileevent($STDIN,readable => sub {
                  my $line = <$STDIN>;
                  $listboxb->insert('end',$line);
                });

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In reply to Re: Perl - TK - Listbox insertion problem by choroba
in thread Perl - TK - Listbox insertion problem by k0rn

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