What awk and send are to files of lines, jq is to json. I find it indispensable on the command line. Jq is a functional language. It took me a bit to get used to it, but now it is one of the first tools I install in a new machine. The linked article is a curated list of jq related resources. After the manual, I found the cookbook helpful.

Did you mean sed by chance?

I started using jq recently for parsing JSON, and it's a wonderful tool. I usually do my data processing, especially JSON, in node but wanted to move more to the command line, and this does the trick. I recommend everyone take the time to learn it.

Thanks for this great list.