sub merge_file {
  my $template_file = shift;
  open(TEMPLATE, $template_file) or print "Error opening template file ($templat
e_file): $!";
  # temporarily disable "uninitialized value" warnings
  $^W = 0;
  while (<TEMPLATE>) {s/<<(.*?)>>/$1/eeg; print;}
  $^W = 1;
  close(TEMPLATE);
}