#!/usr/bin/perl

use strict;
use warnings;

use Graph;
use Graph::Writer::Dot;

my $graph = Graph->new();
$graph->add_edge('a' => 'b');
$graph->set_attribute('color', 'a', 'red');

my $writer = Graph::Writer::Dot->new();
$writer->write_graph($graph, 'mygraph.dot');

system("dot -Tpng mygraph.dot -o mygraph.png");