BEGIN {
  my %oper = (
    0 => 'NON_OPERATIONAL',
    1 => 'UNREACHABLE',
    2 => 'DISCONNECTED',
    3 => 'CONNECTING',
    4 => 'AND_SO_ON',
  );

  sub if_oper_status {
    my $status = shift;
    $oper{$status} || "UNKNOWN($status)";
  }
}