sed - How to extract IP address using sed?

Question

This is for an assignment so I have no choice but to use sed.

Given a file messages, how can I extract all the IP addresses and print them?

I first

Answer 1

You can do that too:

Windows:

ipconfig | perl -nle'/(\d+\.\d+\.\d+\.\d+)/ && print $1' | sed '2 d' | head -n1;

OSX:

ifconfig | perl -nle'/(\d+\.\d+\.\d+\.\d+)/ && print $1' | sed '1 d' | head -n1;