How to Check Ruby Version?

Introduction

Ruby is a dynamic, object-oriented programming language known for its clean syntax and flexibility. It was created in the mid-1990s by Yukihiro Matsumoto, commonly known as Matz. Since its inception, Ruby has undergone several updates and releases, resulting in different versions of the language. These versions introduce new features, improvements, bug fixes, and sometimes even changes in behavior.

To ensure the smooth execution of Ruby programs and to utilize the latest language features, it's crucial to know the version of Ruby installed on your system. Let's dive into various methods to check the Ruby version effectively.

How to Check Ruby Version?

There are several ways to check the Ruby version, depending on your development environment and personal preferences. We will explore the most common methods in the following sections.

In IRB

IRB (Interactive Ruby) is a powerful tool that allows you to interactively execute Ruby code and get immediate feedback. IRB is a great way to learn Ruby and experiment with Ruby code.

Starting an IRB session:

IRB can also be used to check the Ruby version. To begin the IRB session, open your terminal or command line and type irb. You will be welcomed with a prompt that appears as follows:

Output:

You can then type Ruby code at the prompt and press Enter. The code will be executed, and the result will be printed to the console. For example, to check the version of Ruby, execute the following command:

Command:

This command will display the installed Ruby version. For example, if your Ruby version is 3.2.2, it will be displayed as:

Output:

From Command Line

Another straightforward method to check the Ruby version is by using the command line. Type the following command at the command prompt or in the terminal window:

Command:

Executing this command will display the Ruby version installed on your system. For instance, if your Ruby version is 3.2.2, the output will be:

Output:

When you want to check the Ruby version without going into the Ruby console, this approach is quite helpful.

In RVM

RVM (Ruby Version Manager) is a popular tool for managing multiple Ruby versions on a single system.

Some of the benefits of using RVM:

• You can easily install and manage multiple versions of Ruby.
• You can easily switch between different Ruby versions.
• RVM comes with several tools that make it easy to manage your Ruby environment.
• RVM is a popular tool that is used by many Ruby developers.

If you have RVM installed, you can use it to check the Ruby version. Open your terminal and execute the following command:

Command:

This command displays a list of installed Ruby versions, indicating the currently active version with an arrow (=>). The active version is the one that will be used when running Ruby commands. The version number will be displayed next to the arrow. For example:

Output:

The output will include the following information:

• The name of the Ruby version
• The platform that Ruby is running on
• Whether the Ruby version is the default version

In this case, the active Ruby version is 3.2.2.

If you have not installed RVM on your system, the output of the rvm list command will be:

Output:

In rbenv

Similar to RVM, rbenv is another popular Ruby version management tool. If you're using rbenv, you can check the Ruby version by executing the following command in your terminal:

Command:

This command will display the currently active Ruby version, like this:

Output:

The output will include the following information:

• The current Ruby version that is being used
• The path to the file that specifies the current Ruby version

If rbenv is not installed on your system, the rbenv version command will give the following output:

Output:

To list all the installed Ruby versions, you can use the rbenv versions command. For example, on the current machine, the output is:

Output:

This shows that there are two installed Ruby versions: the system Ruby and Ruby 3.2.2.

To use a specific Ruby version for a project, you can use the rbenv local command. For example, to use Ruby 3.2.2 for the current project, you can run the following command:

Command:

This will set the RBENV_VERSION environment variable to 3.2.2 for the current shell session. If you run the ruby --version command, the output will show that you are using Ruby 3.2.2.

To switch back to the system Ruby, you can run the following command:

Command:

This will set the RBENV_VERSION environment variable to the system for the current shell session. When you run the ruby --version command, the output will now show that you are using system Ruby.

Using which

The which command-line utility is frequently used to determine the path to a command. It accepts a command name as an argument, and if the command is present in the environment variable $PATH, it returns the command's path. If the command is not found, which returns nil.

For example, the following code will print the path to the ruby command:

Command:

The output will display the path to the Ruby executable along with the version information, like this:

Output:

By default, this method may not display the specific version number. However, it confirms the presence of Ruby on your system and indicates that it is accessible via the given path. If the output is not nil, you can use the ruby -v command to find the exact version.

Using gem env

The gem command in Ruby is primarily used for managing RubyGems, the package manager for Ruby. However, it can also provide information about the Ruby version. Open your terminal and execute the following command:

This command will display detailed information about the Ruby environment, including the version. The output will contain a section dedicated to Ruby, showing the version number, patch level, and platform, like this:

Checking Ruby Version in IDEs or Text Editors

Many integrated development environments (IDEs) and text editors provide features and plugins that facilitate Ruby development. These tools often include functionality to check the Ruby version used in your projects.

For example, in Visual Studio Code (VS Code), you can utilize extensions such as "Ruby" or "Ruby Solargraph" that provide language support for Ruby. These extensions typically display the active Ruby version in the status bar or give a command to check the Ruby version within the IDE.

In RubyMine, a specialized IDE for Ruby development, you can navigate to the project settings or preferences to find the Ruby SDK configuration. This section usually displays the active Ruby version and allows you to switch between different Ruby installations.

Similarly, other popular text editors like Atom and Sublime Text have plugins or settings that allow you to determine the Ruby version being used. Most of these plugins provide the following:

• A command palette option.
• Menu item.
• A specific configuration file where we can access the Ruby version information.

Checking Ruby Version in Frameworks or Applications

When working with frameworks or applications built on Ruby, it's essential to understand how to check the Ruby version within the context of that specific framework or application.

For instance, in Ruby on Rails, a widely-used web application framework, you can open a terminal and navigate to your Rails project directory. Then, execute the following command:

Command:

This command will display the version of Rails being used in your project, which indirectly indicates the Ruby version it relies on.

In Sinatra, a lightweight web application framework, you can include a Ruby file called app.rb in your project. Within this file, you can add the following code snippet:

Code:

Running the Sinatra application and observing the output will reveal the Ruby version being utilized.

Checking Ruby Version in Docker or Virtual Environments

When working with Docker containers or virtual environments, it is important to know how to determine the Ruby version within those environments.

In the case of Docker, you can access a running container's shell by executing:

Command:

Once inside the container's shell, you can execute the relevant Ruby version command, such as ruby --version, to retrieve the installed Ruby version.

Virtual environments, such as those created using tools like Vagrant or VirtualBox, typically mimic a separate development environment. Inside these environments, you can open a terminal or command prompt and execute the appropriate Ruby version command, such as ruby --version, to check the Ruby version specific to that virtual environment.

Online Tools for Ruby Version Detection

There are online tools available that can analyze codebases or projects written in Ruby and provide information about the Ruby version requirements. When working with codebases that might not have clear documentation indicating the required Ruby version, these tools are especially helpful.

One example of such a tool is "Ruby Version Manager" (RVM) Online. It allows you to upload your Ruby project or provide a repository URL. The tool then analyzes the code and provides insights into the required Ruby version based on the project's configuration files, such as the .ruby-version file or the Gemfile.

Another popular tool is "Reek's Ruby Version Finder." It scans your Ruby project and identifies the Ruby version requirements by examining the project's source files and the Gemfile.lock. The tool then generates a report indicating the Ruby versions that would be compatible with the project.

Checking Ruby Version in Package Managers (Using Bundler)

Ruby package managers like Bundler, Rake, or RubyGems can also provide ways to check the Ruby version.

When using Bundler, which is commonly used for dependency management in Ruby projects, you can run the following command in your project's directory:

Command

This command will display the Ruby version specified in your project's Gemfile.lock, which represents the required Ruby version for the project.