Many of these regexes should not be used on user input, at least not if your regex library backtracks (uses NFAs), because of the risk of ReDoS: http://en.wikip

Many of these regexes should not be used on user input, at least not if your regex library backtracks (uses NFAs), because of the risk of ReDoS: http://en.wikipedia.org/wiki/ReDoS http://en.wikipedia.org/wiki/ReDoS Trying to shoehorn NFAs into parsing stuff that isn't a regular expression is generally a bad idea. (See: Langsec.)