gistfile1.txt

sub _relayer {
  my ($fh, $layers) = @_;
  _debug("# requested layers (@{$layers}) to $fh\n");
  my %seen;
  my @unique = grep { $_ ne 'unix' and $_ ne 'perlio' and !$seen{$_}++ } @$layers;
  _debug("# applying unique layers (@unique) to $fh\n");
  binmode($fh, join(":", "", "raw", @unique));
}