sub ReadFile {
  my ($filename) = @_;
  local $/; # undef $/ for slurping in whole file

  open (FILE, $filename) or 
    die "Error in reading from $filename: $!\n";
  
  my $content = <FILE>;
  close (FILE);

  $content =~ s/^(?!--|\n).*\n//mg; # => see japhy's answer
  return ($content);
} # ReadFile