fzf is a tool that you can use to select items from a list. I think it’s most popularly used to search your shell history (as a Ctrl+R replacement in bash).

I’ve honestly still never found a use for fzf myself (other than fzf.vim which is amazing) but I just learned that you can use it to review a git commit like this and I thought that was really cool. You can scroll up and down through the files on the left and it’ll display the diff on the right:

#!/bin/bash
commit=${1:-HEAD}
git show --stat=120 --format="" "$commit" | \
           grep '|' | \
           fzf --ansi \
               --disabled \
               --bind 'j:down,k:up,q:abort' \
               --preview="echo {} | sed 's/ *|.*//' | xargs -I% git show --color=always $commit -- %" \
               --preview-window=right:60%

You can also use fzf as a sort of “jq playground” like this:

#!/bin/bash

printf '' | fzf --print-query \
  --preview "jq -C {q} '$1' 2>&1" \
  --preview-window=up:80%

I think it’s really cool that you can use fzf (which is theoretically a search tool) to implement lots of UIs that aren’t doing search at all, like these two!