local $TODO = "-alpha and -fullscreen not yet implemented";

Getting fullscreen attribute is not yet implemented for X11

{setting/unsetting fullscreen does not change the focus}

{change -fullscreen after map});
# Query above should not clear fullscreen state

and many more such hits

##</code><code>##

#!/usr/bin/perl
use Tk;
my $mw = new MainWindow;

$mw->after(10,sub {
   $mw->FullScreen(1);
   $mw->bind('all'=> '<Key-Escape>' => sub {exit;});
   $mw->focusForce;
   $mw->update;

});

MainLoop;

##</code><code>##

#!/usr/bin/perl
use Tk;

my $mw = new MainWindow;

$mw->bind('all' => '<Key-Escape>' => sub {exit;});

$mw->FullScreen(1);
$mw->grabGlobal;
$mw->focusForce;

MainLoop;

##</code><code>##

#!/usr/bin/perl
use Tk;

my $mw = new MainWindow;
$mw->geometry($mw->screenwidth . 'x' . $mw->screenheight . '+0+0');

$mw->bind('all' => '<Key-Escape>' => sub {exit;});

MainLoop;