Pre-Requisites:
* Homebrew

Install rbenv using:
brew install rbenv

Add the following to your terminal profile (.bash_profile or .zshrc etc):

# rbenv
export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init -)"

Relaunch the Terminal or enter the following comand for the profile changes to take effect
source path_to_your_terminal_profile

Ensure that Terminal launches with no errors.
If any, please check your syntax in terminal profile.

Verify that rbenv is installed using:
rbenv -v

Install desired version of Ruby. As of this writing current stable version is 2.5.0
rbenv install 2.5.0

Verify ruby versions installed using:
rbenv versions

Change permissions on rbenv ruby versions directories
- chmod ug+wx ~/.rbenv/versions

The last command gives the Users and Groups Read and Write permissions to the versions directory where all the gems shall be stored.
If any of the commands throw errors of PERMISSION, prepend sudo to the command and run it again.
e.g sudo chmod ug+wx ~/.rbenv/versions

Lastly, Install Rails:
gem install rails or sudo gem install rails

Confirm rails is installed using:
rails -v

And you're ready and set to start building Ruby on Rails applications.

Create your projects using:
rails new project_name

This will create a folder project_name and install all the necessary gems and dependencies.

Run your rails app:
- cd project_name && rails server

This spins up a server and runs your app on 0.0.0.0:3000
which is locally: localhost:3000

More detailed Reads:
- http://guides.rubyonrails.org/getting_started.html
- https://www.ruby-lang.org/en/documentation/

Happy Railing!

Photo by Matthew Mendez on Unsplash