From: "David A. Black" <dblack@...>
Date: 2008-07-03T19:48:27+09:00
Subject: Re: yet another regexp problem

Hi --

On Thu, 3 Jul 2008, shaman wrote:

> Hello-
>
> I need to match any string which contain:
>
> any 3 letters
> any 3 digits _but_not_123_
> any 3 letters
>
> so:
> xxx765xxx should match
> vvv123vvv should be omitted

Try this: /[[:alpha]]{3}(?!123)\d{3}[[:alpha:]]{3}/

It uses negative lookahead. The \d{3} part only matches if it occurs
at a point where the next thing in the string is not "123".

I'm also using the POSIX "alpha" character class, which should be
locale-sensitive. You can also use [A-Za-z] if that's sufficient.


David

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