Update ruby version with rbenv

update-ruby.sh

#!/bin/bash

#This command lists all the ruby versions available for install. Make sure the ruby version you want to install is shown on the list
#In this case we will be looking to install 2.3.1
rbenv install --list

#In case the ruby version (2.3.1) you want to install is not on the list, you will have to update both the rbenv 
#and the ruby_build/plugin repositories

#Run the following two commands to update the corresponding git repositories (assuming both are installed inside your home folder)
cd ~/.rbenv; git pull;
cd  plugins/ruby_build; git pull;

#List all the ruby versions to install, and make sure 2.3.1 is listed toward the beginning, above the jruby versions
rbenv install --list

#Install ruby 2.3.1 (this command will build ruby from scratch, so don't worry if it takes about five mins or longer)
rbenv install 2.3.1

#When the above command is finished running, update the ruby version on your system to 2.3.1 and rehash.
rbenv global 2.3.1; rbenv rehash;

#Install bundler, which will be useful to update the gems in your Gemfile.
gem install bundle

####Only for RoR users####

#Now you can go to the folder of your RoR project, and run bundle update. This will install all the dependencies with the new version of ruby.
#Note: There are some gems that you may have to install manually (with the gem install command).
bundle update

#Fire up your rails server and make sure everything is working as it should.
rails s

#If you are satisfied with the installation process, you can remove older versions of ruby using rbenv. In this case we will be 
#uninstalling version 2.2.2.
rbenv uninstall 2.2.2; rbenv rehash;