There are a number of forum websites which support displaying code blocks in comments, but use the annoying and impractical "indent by 4 spaces" convention, rather than the manifestly superior "surround by backticks" convention.
Most notably Hacker News and Reddit. On Reddit, backticks are possible, but 4 spaces ensures the blocks is also formatted correctly for users of old.reddit.com.
This tool simply indents whatever is in the clipboard by 4 spaces.
Tested on Linux, should work on Windows, won't work on Mac.
Note that if you're a linux user, it operates on the clipboard, not the primary
selection. If you're using xclip, you'll need to pass -selection clipboard.
$ stack install