There may be more than one way to do it, but there's also more than one way to think about (doing) it.

sub display_template
{
  my %opts = @_;

  my $output;
  my $files = $opts{file};
  my @files = ref $files ? @$files : ($files);

  unless ($opts{no_header} or $opts{bare})
  {
    my $header = $opts{header} || 'header.tmpl';
    my $tmpl = HTML::Template->new($header);
    $tmpl->param(...); # common params
    $tmpl->param(%{$opts{header_param}}) if $opts{header_param};
    $output .= $tmpl->output();
  }

  foreach my $file (@files)
  {
    my $tmpl = HTML::Template->new($file);
    $tmpl->param(...); # common params
    $tmpl->param(%{$opts{params}}) if $opts{params};
    $output .= $tmpl->output();
  }

  unless ($opts{no_footer} or $opts{bare})
  {
    my $footer = $opts{footer} || 'footer.tmpl';
    my $tmpl = HTML::Template->new($footer);
    $tmpl->param(...); # common params
    $tmpl->param(%{$opts{footer_param}}) if $opts{footer_param};
    $output .= $tmpl->output();
  }

  $output;
}
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That's pretty close to what I use for mine. As you can see, it takes named parameters - things like "file" which can take either a single file name, or an arrayref of filenames, or 'header' to name the header file (defaults to 'header.tmpl'), or 'no_header' to remove the header altogether, or 'bare' to remove both header and footer at the same time. Then there's 'header_param' which is a hashref of parameters to pass in to HTML::Template for the header, similarly for the main files and the footer. And then, it returns the whole thing - because I use CGI::Application, and that's the way C::A works.

Hope that helps.

Well as others have stated using some kind of SSI parser within CGI would probably get you where you're going, however I don't feel this is the best way.

In my opinion the best way is to turn your logic around. Instead of trying to include your CGIs in a layout, include your layout in your CGIs with a templating system such as HTML::Template. Tanktalus seems to be doing that in his example, though I would use the templating engine's logic rather than his method of including certain things.

If you need to keep your links the same (since in my method you would call a CGI script directly rather than an HTML file) I would simply use the URL rewritting features of Apache to get people to the correct link.

HTH

<!-- SCRIPT TEMPLATE BREAKS HERE -->
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I need everything above that line stored as $1, everything below as $2.

My best attempt would be

use LWP::Simple;
my $content = get("http://www.url.com/scripttemplate.shtml");

my $breakline = "<!-- SCRIPT TEMPLATE BREAKS HERE -->";

while ($content)
{
  $content =~ /(.*)$breakline(.*)/);
}
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