sub remove_cruft
{
  my @lines;
  if (@_ > 1)
  {
    # lines were passed in.
    @lines = @_;
  }
  # we either got a filename or a filehandle.
  elsif (ref $_[0]) # assume object is a filehandle.
  {
    @lines = <$_[0]>;
  }
  else # must be a filename.
  {
    my $fh = IO::File->new(shift, 'r');
    @lines = <$fh>;
  }
  # do stuff to @lines;
  @lines;
}