Microsoft Excel. Manipulating tens or hundreds of thousands of rows, including cross-referencing across tables, is just so satisfying and much faster than doing it with a DB or code. Alternative spreadsheet software do some things better, but they don't come close as a complete package, I don't regret paying for it myself for the first time in my life. It such a life saver in a pinch.
Obligatory Spolsky intro to Excel: https://www.youtube.com/watch?v=0nbkaYsR94c
Yeah, just yesterday. Hacky output from `nslookup`, not ideal but it’s all we had. Tens of thousands of rows. No IDE with regex capabilities available.
Excel to the rescue! Took me about five minutes to extract exactly what I needed.
If you can use dig output, the next time you need to do something like this you might find 'jc' helpful: https://github.com/kellyjonbrazil/jc