You may be looking for seek and tell or even File::ReadBackwards - but given the actual contents here, you may be better off looking at the Cvs modules.

That said, it's not entirely clear to me what your definition of "last" is - are you looking for 1.1 or 1.3 in your example? 1.1 is the last one in the file, but 1.3 is the last (latest) one put into the file.