Re^4: how to find what's not there with a regex?

hmmm.... (?! xyz ) { what-bang? :) }

New one on me, but that's an excellent idea.

Stop when you see xyz...

Perl++ never ceases to amaze me.

Comment on Re^4: how to find what's not there with a regex?

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Re^5: how to find what's not there with a regex? by ikegami (Patriarch) on Aug 24, 2005 at 15:15 UTC
It's the zero-width negative lookahead operator. In English, it means "not immediately followed by", and it doesn't move `pos`, so the next item in the regexp will start matching as if the `(?!...)` wasn't there. It's almost always used as `(?: (?! ...regexp... ) .)*` or `(?: (?! ...regexp... ) .)+` Anything else is should be very carefully inspected.	[reply] [d/l] [select]