.sh & ip address

George Davidovich freebsd at optimis.net
Wed Jun 23 02:47:42 UTC 2010


On Wed, Jun 23, 2010 at 10:31:51AM +0800, Aiza wrote:
> I looking to take the last group number in a ip address and bump the
> number by 1.  BY the way is there some name for each group of numbers in
> the ip address?

Octet.
 
> Something like.
> 
> org_ip="10.0.10.2"
> short_ip=need command to strip off the 2 so short_ip contains 10.0.10.
> and ip_suffix= ends up holding the 2, then add 1 to the ip_suffix.
> ip_suffix=$(( ${ip_suffix + 1 ))
> org_ip="${short_ip}${ip_suffix}"
> 
> Thinking there must be some common way of manipulating ip addresses that
> I just don't know about.

man sh | less -p"Parameter Expansion"

org_ip=10.0.10.2 
${org_ip##*.}       # yields 2
${org_ip%.*}        # yields 10.0.10

Do read the manpage.

-- 
George


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