#!perl
use strict;
use GD::Graph::bars;

my @data1 = (['Windows', 'Linux', 'Solaris'], [150,250,350],[100,200,300]); 
my @data2 = (['Windows', 'Linux', 'Solaris'], [100,200,300],[150,250,350]); 

create_graph('file1.gif',\@data1);
create_graph('file2.gif',\@data2);

sub create_graph {

  my ($file,$data) = @_;
  my $graph = new GD::Graph::bars(900,600); 
  $graph->set(
  x_label => 'x_Label', 
  x_label_position => 1/4, 
  x_label_vertical => 1, 
  y_label => 'Minutes', 
  y_max_value => 700, 
  y_tick_number => 14, 
  title => 'Graph_Title '.$file, 
  bar_width => 35, 
  cumulate => 1, 
  dclrs => ['yellow', 'cyan'], 
  bgclr => 'white', 
  fgclr => 'lred', 
  values_vertical => 0, 
  valuesclr => 'black', 
  accentclr => 'red', 
  shadowclr => '#F7E7CE', 
  shadow_depth => 0, 
  legendclr => 'lblue', 
  show_values => 1); 

  # graph
  my $gd = $graph->plot($data) 
    or die $graph->error;  
  open IMG, '>',$file or die $!;
  binmode IMG;
  print IMG $gd->gif;
  close IMG;
}