From: "toulax@..." <toulax@...>
Date: 2007-06-29T03:55:02+09:00
Subject: Help with regular expression

How can I make a regular expression that will match everything, unless
it contains a certain string then it will match nothing.

For instance, let's say it should not match "bar", then:

"foo" => "foo"
"bar " => nil
"foobar" => nil

Thanks in advance