how to express the following regular expression?

[Carl Howells]

"Stephen" <fungho at sinaman.com> wrote...
> I want to search the following formats:
>
> ([1234567890]*)R
> or
> P([1234567890]*)
>
> this means there must be a 'P' before the number or a 'R' after the
> number. However, I think I can't use this:
> P?([1234567890]*)R?
> because the number without P and R is also matched!
>
> How can I express it?

Exactly you you'd expect...  One or the other:

(P\d*)|(\d*R)

You could also use [0-9] in place of \d, if you were really set on using the
[] notation.  But there's no reason to use [1234567890].