#!/usr/bin/perl

use strict;
use warnings;

use Tk;

use Data::Dumper;


my $mw = new MainWindow;
$mw->title ("Perl/Tk - Entry Valdiation");

my $entry1 = $mw->Entry ( '-width'           => 30,
                          '-validate'        => 'key',
                          '-validatecommand' =>
                          sub
                          {
                              print Dumper( \@_ );                              
                                                           
                              return 0 unless( $_[0] =~ m/^[0-9a-fA-F]+/ )
                          } );

$entry1->pack();

MainLoop;