I'd like a tool similar to this but for sed or awk usage. Like to see interactively what would be the output for given input and command. Particularly for the toolchain distributed with Ubuntu. I believe demand for such tool would be greater than just me. Let me know if you know one!
Ultimate Plumber
https://github.com/akavel/up
HN discussion: https://news.ycombinator.com/item?id=26644110