Not really. Your use of the /i switch is meaningless in this context. The point here is to pull words one by one from the text file, and see if there exists a hash element whos key matches that word. But hash keys themselves are case dependant. All that the regexp is doing is to grab one "word" at a time. That word still has to be found to be a hash key from the keyword hash. There is actually nothing in the regular expression I've used that would be affected by the /i switch in any way, other than to possibly slow down the regexp's execution speed.

As a matter of fact, my solution is the only one posted thus far in this thread that wouldn't match case insensitively when the /i switch is added. Your post is a good observation if applied to the other answers provided in this thread.