Hi Perl Monks

I want to have a doughnut chart for Hard Disk. It should display Used space, Free Space and Total etc.. Now, I wrote a code for it. It's a pie chart.. How can I get a doughnut for it. I want to display with CGI.

Here's my code

#!/usr/bin/perl 
use CGI ':standard';
use strict;
use warnings;
use GD::Graph::pie;

my $cmd_1 = "sudo df -h |grep /var |awk '{print \$2}' | sed -e 's/.\$/
+/'";   
my $cmd_2 = "sudo df -h |grep /var |awk '{print \$3}' | sed -e 's/.\$/
+/'";   

my $result_used = qx/ $cmd_1 /; #$result_used shows 1.4
my $result_free = qx/ $cmd_2 /; #$result_free shows 85

# Both the arrays should same number of entries.
my @data = (['Used', 'Free'],
            [$result_used, $result_free]);

my $mygraph = GD::Graph::pie->new(300, 300);
$mygraph->set(
    title       => '/var Partition, Size in GB',
    '3d'          => 0,
    #'3d'          => 1,
) or warn $mygraph->error;

$mygraph->set_value_font(GD::gdMediumBoldFont);

my $myimage = $mygraph->plot(\@data) or die $mygraph->error;

print "Content-type: image/png\n\n";
print $myimage->png;
[download]

I think Doughnut chart is NICER. But, I can't find many docs for them.

Can U guys help me? Better methods are also welcome...