netmask in a script

[Eric Shubert]

On 10/26/2011 09:49 PM, Dazed_75 wrote:
> I would like to apply a netmask to an arbitrary IP in a bash/dash script
> (e.g. apply 255.255.255.0 to 173.10.3.155 to get 173.10.3.0).  Is there
> any easy way to do that without taking the IP apart, doing 4 operations
> and reassembling the results?
>
> --
> Dazed_75 a.k.a. Larry
>
> The spirit of resistance to government is so valuable on certain
> occasions, that I wish it always to be kept alive.
>    - Thomas Jefferson
>

http://tldp.org/LDP/abs/html/ops.html
See "bitwise operators" about half way down the page. I think that's 
what you're looking for.

-- 
-Eric 'shubes'