use Tk;

sub tick;

$MYBUILDDIR="c:\\build"; #Dont forget to backslash the backslashes

$total_objects = 303; #Number of object files a full build would create
$progressbar_width = 2*$total_objects;
$progressbar_height = 50;
$timer_interval=10; #in seconds

$MW = MainWindow->new;
$MW->bind('<Control-c>' => \&exit);
$MW->bind('<Control-q>' => \&exit);

$canvas1 = $MW->Canvas(
  '-width' => $progressbar_width,
  -height => $progressbar_height,
  -background => 'black'
) -> pack;
$newval = 10;

$start = $MW->Button(
    -text         => 'Start', 
    -command      => sub {tick},
);

$start->pack(-side => 'left', -fill => 'both', -expand => 'yes');

sub tick {
    # Update the counter every 5 seconds
    $MW->after($timer_interval * 1000, \&tick);
    $num_objs = @objects = glob($MYBUILDIR . "*.o");
    print "\n$num_objs out of $total_objects built so far...";
    $newval = ($num_objs / $total_objects)*$progressbar_width;
    $canvas1->create ('rectangle','0','0',$newval,$progressbar_height,-fill=>'red');
} 

MainLoop;