How to Use the Rails Command (with Examples)

Rails is a powerful server-side web application framework written in Ruby. Known for its “Convention over Configuration” philosophy, Rails simplifies the development of database-backed web applications. It operates as a Model-View-Controller (MVC) framework, promoting organized and efficient code. The Rails command-line interface provides a wide range of utilities for managing Rails projects, from creating new applications to launching servers and accessing the console.

Create a New Rails Project

Code:

rails new "project_name"

Motivation:

Creating a new Rails project is the first step in Rails development. This command sets up a fully configured Rails application with a standard file structure and ready-to-use components. It’s the foundation upon which you’ll build your application, enabling rapid development through preconfigured settings.

Explanation:

• rails new: The new subcommand instructs Rails to generate a new project, providing the necessary directories, files, and structures that conform to Rails conventions.
• "project_name": You replace this with your desired project name. This name will be used to create a directory where all the project files will be stored.

Example Output:

When you run this command, Rails creates a directory named project_name, containing subdirectories for app components like models, views, and controllers:

  create  
  create  README.md
  create  Rakefile
  create  .ruby-version
  create  config.ru
  create  .gitignore
  create  Gemfile
  ...
  create  app/views/layouts/application.html.erb
  create  app/assets/images/.keep

Start Local Server for Current Project on Port 3000

Code:

rails server

Motivation:

Once you have set up your Rails application, you need a way to test and view it locally. Starting a development server allows you to see your application live in your web browser, making testing and development more intuitive and interactive.

Explanation:

• rails server: The server subcommand starts the Rails server. By default, it listens on port 3000, making it easy to access locally via a web browser at http://localhost:3000.

Example Output:

With no errors in setup, the output should show:

=> Booting Puma
=> Rails 6.1.4 application starting in development 
=> Run `bin/rails server --help` for more startup options
Puma starting in single mode...

* Listening on http://127.0.0.1:3000

Start Local Server for Current Project on a Specified Port

Code:

rails server -p "port"

Motivation:

In situations where the default port 3000 is unavailable, or if you’re running multiple Rails applications simultaneously, you can specify a different port. This flexibility ensures you can customize your environment to your needs without port conflicts.

Explanation:

• rails server: Starts the Rails server.
• -p: This option allows you to specify the port number.
• "port": Replace "port" with your desired port number. For example, if you want to run it on port 4000, you would execute rails server -p 4000.

Example Output:

If successful, the terminal will indicate the server’s status:

=> Booting Puma
=> Rails 6.1.4 application starting in development 
=> Run `bin/rails server --help` for more startup options
Puma starting in single mode...

* Listening on http://127.0.0.1:4000

Open Console to Interact with Application from Command-Line

Code:

rails console

Motivation:

Sometimes you need to interact with the Rail application from the command line directly. The Rails console provides an interactive shell that allows you to query your database, test code snippets, or diagnose bugs in real-time.

Explanation:

• rails console: Starts an interactive Ruby session with your Rails environment loaded. This is useful for testing models, checking database records, and running Rails commands interactively.

Example Output:

Launching the console will show:

Loading development environment (Rails 6.1.4)
irb(main):001:0>

Check Current Version of Rails

Code:

rails --version

Motivation:

Knowing the version of Rails your application is based on is crucial for compatibility with gems, checking for updates, or seeking help as different versions may have different features or require specific configurations.

Explanation:

• rails: The main command to perform actions related to Rails.
• --version: This option queries the current version of Rails installed in your environment.

Example Output:

Your terminal displays the Rails version:

Rails 6.1.4

Conclusion:

The Rails command is an essential tool for any Ruby on Rails developer. It streamlines the process of starting new projects, testing applications locally, interacting with applications through the console, and managing dependencies. By mastering the Rails command, developers can leverage its power to enhance productivity and manage applications effectively.