Remove everything except regex match in Vim

Question

My specific case is a text document that contains lots of text and IPv4 addresses. I want to remove everything except for the IP addresses.

I can use :vglobal<

Answer 1

Assuming is your regex to match an IP address, I presume you could do something like :

:%s/.\{-}\(\).*/\1/g

where \1 is the first matched group (the address alone), and .\{-} used for non-greedy matching.