====== regex tips ======

Awesome online tester: [[http://gskinner.com/RegExr|RegExr]]

Positive and Negative Lookahead and Positive and Negative Lookbehind

[[http://www.regular-expressions.info/lookaround.html|Lookaround at regular-expressions.info]]

Some other handy tips: [[http://www.perlmonks.org/?node_id=518444|using Look-ahead and Look-behind]].

Keywords: grep