Guide to Getting Started with Ruby

Are you developing on a Windows or Linux computer?

Then this guide will not work for you. These things might:

• Official list of ways to install Ruby, as given by the documentation.
• Windows users: try this RubyInstaller, or this TeamTreeHouse Rails installation guide.
• Linux users: check out the official list of ways to install Ruby on your dystro.

Okay, you’re a Mac user. Have you ever used your Terminal before?

Yes? Okay, you’re good to go.

No? Don’t go any further before learning about your Terminal. Here’s resources to get you started:

• Our Command line interfaces introduction
• TeamTreeHouse’s introduction to the Mac Terminal
• Ashley Noland’s great guide to getting started with Terminal
• Take the Command Line Crash Course, a really excellent and concise tutorial getting you up and running with navigating the shell and writing bash commands.

Note: the terms command line, command-line, command line interface (CLI), terminal, shell, and bash all mean the same thing: a text-based interface to your computer where you can run bash code.

Part 0: What we’ll be doing

You’ve decided to get started with Ruby on your local computer. Awesome! Ruby is a great back-end language with a lot to recommend it, not the least of which is a mature ecosystem of tools and communities.

Here’s the process this guide will take:

• Install a package manager, Homebrew. This is like the Mac App Store, but for the command line, and free. It will make it easy to download everything else you’re going to be installing.
• Install rbenv, a Ruby version manager. Macs already come with a version of Ruby installed, but this is a protected version and is only open to the operating system to use. You’ll need rbenv because it will allow you to download multiple versions of Ruby and specify which one is going to be used, without affecting the protected version of Ruby that your operating system uses.
• Install Ruby. Using rbenv, we’ll install a recent version of Ruby to your computer.
• Manage some required configurations for installing gems (Ruby’s external libraries), and to ensure you’re working with the right version of Ruby when you need it.
• Install Pry, a very useful gem, to test that we’ve done everything correctly.

READ YOUR TERMINAL OUTPUT. If there are any errors, they will be obvious, and you need to respond correctly to them.

Part 1: Installing a package manager

Open your terminal. Install Homebrew, a package manager, by pasting the following code into your prompt:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

This might prompt you for your password. Type in your password–it won’t show anything as you type, but it will be listening nevertheless. Press enter to continue.

It’ll take some time to finish installing, don’t continue until your prompt returns.

Review the output to make sure there were no errors and the process of installing didn’t stop or break/error out.

Part 2: Installing rbenv, a Ruby version manager

Check if you already have rbenv installed by inputting the following command in your terminal:

rbenv -v

The -v flag usually stands for version or verbose, which means, “show me information about this program”. If you get output like rbenv 1.1.0, you already have it installed, so move on to the next part.

If you don’t have rbenv installed, input the following command:

brew install rbenv

Check the output to make sure everything installs as expected.

Part 3: Installing Ruby with rbenv

In the terminal, type the following:

rbenv install 2.6.0

This command tells rbenv to install Ruby, specifically Ruby version 2.6.0. There are other versions, but this is a good, current version (as of Jan 18, 2017).

This will also take some time.

Part 4: Configurations

When your rbenv is done installing Ruby, run the following code:

echo 'eval "$(rbenv init -)"' >> ~/.bash_profile

There won’t be any output when you run this command.

Now, let’s set the correct Ruby version to be used whenever you want to write some Ruby code and run it:

rbenv global 2.6.0

This means, “Set the global version of Ruby in this computer to be 2.6.0”.

Finally, run the following code:

gem update --system

This will update where your gems will download, making sure they will always download to a subfolder within the Ruby 2.6.0 version, which will allow you access. This will also ensure you have the most recent version of rubygems installed on your computer, to allow you to download gems from here on.

Part 5: Download a gem to test that everything works

Quit and reopen your terminal.

Run the following code to download pry, a great gem used to pause programs in the middle in order to inspect values:

gem install pry

If nothing errors out, and you get some output like 4 gems installed, you’re all set! You now have Ruby installed and can be on your merry way.

You’re done!

You can write Ruby files on your computer now. Here’s a list of things to try out:

• Take the official “Ruby in 20 minutes” tutorial.

• Create and run a Ruby file.

  • In your terminal, navigate to a folder where you’ll be storing your programming files.
  • Run touch test_file.rb to create a blank file with an .rb extension, for Ruby files.
  • If you don’t have one already, download a text-editor like Atom (a text editor built by Github) or Sublime (probably the most popular text editor).
  • Open your new file in your text editor and write some code, such as puts 'Hello world!'.
  • Save your file.
  • In your terminal, run the file using the command ruby test_file.rb and see whatever output be printed on the screen.

• Continue your learning by checking out our resources on Ruby.