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

use Tk;
use Tk::ProgressBar;

my $w = MainWindow->new();
my $p = $w->ProgressBar(
  -blocks => 1,
  -width  => 20,
  -length => 200,
  -from   => 0,
  -to     => 100,
  -variable  => \(my $foo),
)->pack();

$foo = 0;
$w->repeat(10, sub { $foo = ($foo + 1) % 100 });
MainLoop;