Is there an easy way to list CLI tools installed on macOS? So I have various command line tools like node, stats, etc which help me with day to day tasks, however I've noticed they don't show up in storage manager under applications and am unsure if there's a way to list all of those tools and completely remove all the files of the ones I don't use any more. It'll show as extra system memory use. It's not a big deal however I don't want to waste space. Is there a tool to manage all of this?
Basically every directory listed in PATH besides the standard ones (/usr/bin:/bin:/usr/sbin:/sbin) contains user-installed, so running ls on these directories gives you the list for them and you can use the usual Unix tools like du to calculate sizes. 

To make managing user-installed tools easier you can rely on a package manager. Homebrew is the package manager of choice for many users.