I just came up with this idea of abusing fzf --preview
flag to turn simple commands into live REPL with instant
feedback loop - GitHub repo
Examples
Live awk preview
$ echo '' | fzf --print-query --preview 'echo "a\nb\nc\nd" | awk {q}'
Peek into contents of a directory
$ echo '' | fzf --preview 'ls {q}'
Execute a Ruby script
$ echo '' | fzf --print-query --preview 'ruby -e {q}'
I have many more ideas for these. For now I only made 3 because I wanted to release this ASAP. If you like it, please check the repo which will be updated regularly here. Also, feel free to contribute your own ideas.