How to Install Ruby on Ubuntu 20.04 LTS

Ruby is popular, dynamic and flexible open source programming language. It has an elegant syntax that is natural to read and easy to write. We’ll show how to install Ruby using the Rbenv and RVM scripts on your Ubuntu 20.04 system. Choose the installation method that is most appropriate for your setup and environment.

Install Ruby with Rbenv#

Rbenv is a Ruby version management tool that allows you to switch Ruby versions easily. By default Rbenv doesn’t handle installing Ruby versions so we also need to install ruby-build that will help you to install specific version of Ruby. Follow the below instruction as root or sudo user to install Ruby with Rbenv:

Update the package index list by typing:

sudo apt update

Now, install dependencies for installation of rbenv and ruby-build:

sudo apt install git curl libssl-dev libreadline-dev zlib1g-dev autoconf bison build-essential libyaml-dev libreadline-dev libncurses5-dev libffi-dev libgdbm-dev

After that, simply clone rbenv GitHub repository into the ~/.rbenv folder:

git clone https://github.com/rbenv/rbenv.git ~/.rbenv

Next, run the following commands to set up rbenv:

echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc

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

exec $SHELL

Now download the ruby-build plugin into the plugins folder of rbenv as follows:

git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build

echo 'export PATH="$HOME/.rbenv/plugins/ruby-build/bin:$PATH"' >> ~/.bashrc

exec $SHELL

The ruby-build plugin adds the install command to rbenv.

To get a list of all Ruby versions that can be installed with rbenv enter:

rbenv install -l

To install Ruby version 2.7.1 and set it as default version, type:

rbenv install 2.7.1

rbenv global 2.7.1

Verify installation by issuing below command:

ruby -v

Install Ruby using RVM#

RVM is a command-line tool which allows you to easily install, manage, and work with multiple ruby environments from interpreters to sets of gems.

Install the dependencies required to build Ruby from source:

sudo apt update

sudo apt-get install libgdbm-dev libncurses5-dev automake libtool bison libffi-dev

Run the following commands to add the GPG key and install RVM:

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB

curl -sSL https://get.rvm.io | bash -s stable

To start using RVM, type:

source ~/.rvm/scripts/rvm

Install the latest stable version 2.7.1 of Ruby with RVM and set it as the default version:

rvm install 2.7.1

rvm use 2.7.1 --default

Verify that Ruby installed properly by checking it’s version:

ruby -v

Ruby Program Example#

We are going to create a simple ruby program. So create a demo.rb file using your favorite editor:

sudo nano demo.rb

Paste below lines in to that file:

puts "Ruby Simple Demo"

Save file and exit from editor using Ctrl+x.

To run demo.rb file issue below command:

ruby demo.rb

It will print simple output as below:

Ruby Simple Demo

Conclusion#

We shown you two methods to install Ruby on Ubuntu 20.04 system. The method depends on your requirements and preferences, while most people prefer using rbenv these days.

If you have any problem or suggestion please leave a comment below.