Ruby on Rails Command Line (Rails) (with examples)
Ruby on Rails is a powerful web application framework written in Ruby that follows the Model-View-Controller (MVC) design pattern. It provides developers with a set of tools and conventions to build robust and scalable web applications.
The Rails command line tool, rails, is a central part of the Rails ecosystem. It allows developers to perform various tasks such as creating new Rails projects, running the local development server, generating code scaffolding, and interacting with the application’s console.
In this article, we will explore different use cases of the rails command by providing code examples and explaining their motivations, arguments, and example outputs.
1: Creating a new Rails project
rails new "project_name"
Motivation:
This command is used to create a new Rails project with the specified project name. It generates the basic directory structure and configuration files needed for a Rails application.
Explanation:
new: This is the subcommand used to create a new Rails project."project_name": Replace this with the desired name for your project. It should be a unique and descriptive name, usually written in lowercase and separated by underscores.
Example Output:
When executing the command rails new "my_project", the output will be a new Rails project named “my_project” in a directory called “my_project”. It will contain the necessary files and folders to start developing a Rails application.
2: Starting the local server for the current project on the default port
rails server
Motivation:
This command is used to start the development server for the current Rails project. The server allows you to locally test and preview your application in a web browser.
Explanation:
server: This subcommand is used to start the local development server.
Example Output:
When executing the command rails server, the output will indicate that the development server is running on the default port (typically 3000). It will display logs of incoming requests and responses, allowing you to test and interact with your application through a web browser.
3: Starting the local server for the current project on a specified port
rails server -p "port"
Motivation:
This command is used to start the development server for the current Rails project on a specific port. It can be useful when the default port (typically 3000) is already in use by another application or when you want to test your application on a different port.
Explanation:
server: This subcommand is used to start the local development server.-p "port": This argument is used to specify the port number on which the server should listen. Replace"port"with the desired port number.
Example Output:
When executing the command rails server -p 4000, the output will indicate that the development server is running on port 4000. You can then access your application by navigating to http://localhost:4000 in a web browser.
4: Opening the console to interact with the application from the command-line
rails console
Motivation:
This command opens an interactive console session with the Rails application, allowing you to execute Ruby code and interact with the application’s models, controllers, and other components.
Explanation:
console: This subcommand is used to open the Rails console.
Example Output:
When executing the command rails console, the output will display the Rails console prompt. From here, you can interactively run Ruby code and execute commands specific to your Rails application. For example, you can query the database, create records, and test out various code snippets.
5: Checking the current version of Rails
rails --version
Motivation:
This command is used to check the current version of Rails installed on your system. It can be helpful when troubleshooting issues or ensuring you have the correct version for your project.
Explanation:
--version: This option is used to display the current version of Rails.
Example Output:
When executing the command rails --version, the output will display the version number of the installed Rails framework. For example, it might display Rails 6.1.3.2 indicating that Rails version 6.1.3.2 is currently installed on the system.
Conclusion
In this article, we explored different use cases of the rails command line tool. We covered creating a new Rails project, starting the local server, opening the console, and checking the current Rails version. These examples demonstrate the versatility of the rails command and how it can streamline the development and management of Rails applications.
