Regex (download)
Early in my career watching other engineers pattern match across a codebase or some logs using regex felt like some kind of inaccessible, dark magic - they could find (and replace) what they were looking ten times faster than I could. If you’ve not spent time learning the ins and outs of regular expressions and committing them to memory then this is an easy way of boosting your productivity - they pop up everywhere you need a string operation and in every context. The deck is built from the guide given in The Linux Command Line plus a bit of experience from watching others. I’ve kept it short so a couple of minutes a day for 2-3 weeks (plus of course changing your workflow to apply the skill consistently) will get you to mastery.