This is a cool idea! I'm not sure if my tactic is much better but I thought of using a source filter:
package CFGPL;
use warnings;
use strict;
our $Comment_Start = '#';
sub import
{
shift;
$Comment_Start = quotemeta shift if @_;
# Read in only our commented code...
open my $own_src_file, '<', $0;
my @perl_code = grep { /^$Comment_Start/ } <$own_src_file>;
close $own_src_file;
die "Config file has no code in comments\n" unless @perl_code;
# Write it back to config file and erase uncommented stuff!
open STDOUT, '>', $0;
print @perl_code;
}
# Filter out the leading comment and runs the code...
require Filter::Simple;
Filter::Simple::FILTER( sub { s/^$Comment_Start//gm; } );
1;
Easy to invoke like:
perl -MCFGPL config.file.