How can I check the version of a package online before installing?
You can get information on each of the hits:
brew info octave
brew info --cask evernote

In both cases, these may require you to &quot;tap&quot; the containing levels, but it gives you the command to run for each as needed.
From the first package information, you should get an info URL of https://github.com/Homebrew/homebrew-science/blob/master/octave.rb and then could inspect the source of that octave installation. Repeat for the cask and then you can decide or not to install one or the other.