Thanks for all the replies, helped a lot.

@choroba - the test code as given didn't help me much... guessing I need to read up on Test::More. Using qr// - I have now picked that up, cheers.

@AnomalousMonk - had to read it twice but now I know the result was what it was not because 'the computer doesn't like me' ;) Thanks.

@Athanasius - I added the first ? quatifier so the expression matches 10-99, didn't indeed realise it introduces an unexpected match as well ...

@Crackers - spotted and fixed the above, cheers :)

@graff - all the spotting and fixing of errors above makes your case indeed... my take on it would be that regexp are good as long as you don't get in deeper than you can easily troubleshoot yourself out of, and that (getting in too deep) is very easily done.

@Discipulus - yes I am reinventing ipv4 address matching, partially as an excercise. Thanks for the links, heading over there now.