On 6/20/07, jmk@plan9.bell-labs.com <jmk@plan9.bell-labs.com> wrote:
> current problem is, given an ip address, say 135.104.9.7
> and an ip mask, say 255.255.255.0,how do i get the result
> of addr & mask using only sed and echo?
>

sitting idly at usenix, not listening to the boring talks. it can be
done, but it's not pretty. hope you don't mind the 36 seconds it takes
to compute:

parr% date; andip 123.124.125.126 255.255.0.127; date
Fri Jun 22 13:43:48 EDT 2007
123.124.0.126
Fri Jun 22 13:44:24 EDT 2007
parr%

now i think i'll go to the beach.