use strict;
use warnings;
use Perl::Tidy;
use CGI qw(:standard);

open FH, '<', '/path/to/perlfile.pl' or die $!;
my $content = do {local $/;<FH>};
my $html;

perltidy(
   source      => \$content,
   destination => \$html,
   argv        => '-html -npod -css=/path/to/perltidy.css',
   errorfile   => '/dev/null',
);

print header,
   start_html(
      -title => 'Colorized Perl',
      -style => { src => '/URL/to/perltidy.css' },
   ),
   $html,
   end_html,
;