#!/usr/bin/perl
use warnings;
use strict; 

use Tk;

my $mw = tkinit; 
my $t = $mw->Text->pack; 
my $b = $mw->Button( 
-text => 'Press Me', 
-command => \&foo,  
)->pack;                                                                                                          

$mw->bind('<Control-a>', [$b => 'invoke']); 
MainLoop; 
 
sub foo {  
    $t->insert('end', "Thank you\n");  
    $t->see('end');   
}