Regex Puzzle
Regex is one of those tools that I use a couple times a year - usually for cleaning up lousy input data.<p>I always end up spending a fair amount of time using tools like:<p><a href="http://regex.inginf.units.it/" rel="nofollow">http://regex.inginf.units.it/</a><p><a href="https://regex101.com/" rel="nofollow">https://regex101.com/</a><p><a href="http://www.regexr.com/" rel="nofollow">http://www.regexr.com/</a><p>And of course stackoverflow.