$ brew update
$ brew install rbenv ruby-build
# Add rbenv to bash so that it loads every time you open a terminal
echo 'if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi' >> ~/.bash_profile
source ~/.bash_profile
sudo gem update --system
Password:
Updating rubygems-update
Fetching: rubygems-update-2.6.8.gem (100%)
Successfully installed rubygems-update-2.6.8
Parsing documentation for rubygems-update-2.6.8
Installing ri documentation for rubygems-update-2.6.8
Installing darkfish documentation for rubygems-update-2.6.8
Installing RubyGems 2.6.8
RubyGems 2.6.8 installed
Parsing documentation for rubygems-2.6.8
Installing ri documentation for rubygems-2.6.8
------------------------------------------------------------------------------
RubyGems installed the following executables:
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/gem
Ruby Interactive (ri) documentation was installed. ri is kind of like man
pages for ruby libraries. You may access it like this:
ri Classname
ri Classname.class_method
ri Classname#instance_method