use Tk;
use Mac::Pasteboard;
$mw = MainWindow->new();

my $t = $mw->Scrolled('Text', -width => 40, -height => 10, -wrap => 'char', -bd => '1', -scrollbars => 'e')->pack(-expand => 1, -fill => 'both', -pady => 2, -padx => [2,0]);

$t -> bind("<<Paste>>", sub{

my $CLIP = Mac::Pasteboard->new();

	#reading what is in the pasteboard
	my ($data, $flags) = $CLIP->paste ();
	#modifying value
	$data .= '_ADDED';
	#setting new value
	$CLIP->clear ();
	$CLIP->copy($data);	

});

MainLoop;