Run Commands on File Change

#memo #tip

I use entr to run commands automatically when files change. Here’s how I use it to run tests.

Use:

ls lib/* spec/* | entr -c bin/test

Notes:

  • Install: brew install entr
  • -c clears the screen before running the command
  • find lib spec -name '*.rb' works the similarly to ls, but I can’t always remember the syntax
  • git ls-files is another option for watching tracked files in a repo
  • watchexec is an alternative to entr, known for being more feature-rich