my $DONT = pack 'ss', 1, 0;
setsockopt( $svr, SOL_SOCKET, SO_LINGER, $DONT ) or warn $^E;

## verify setting
my $QUERY = getsockopt( $svr, SOL_SOCKET, SO_LINGER ) or warn $^E;
printf "\n\n%u %u\n\n", unpack 's2', $QUERY;