Brew Concepts
Internal
Formula
A formula is a package definition written in Ruby. Homebrew comes with a good amount of existing formulae, and they are stored as /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/<package-name>.rb.
New formulae can be can be created. Instructions are available here: https://docs.brew.sh/Formula-Cookbook. The sequence is:
brew create <URL>
where <URL> is a zip or tar file, installed with
brew install <formula>
and debugged with:
brew install --debug --verbose <formula>
Formula API: http://www.rubydoc.info/github/Homebrew/brew/master/Formula
Common Formulate
bash
/usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/bash.rb
Bottle
Tap
Cask
User Space vs. System Space
Commands
update
Fetches the latest version of Homebrew and all formulae and upgrades.
doctor
Checks the Homebrew installation for potential problems and exit with a non-zero status if potential problems are found.
cleanup
Remove old version from cellar for all installed (or specified) formulae. Old downloads from the Homebrew download-cache are deleted.