Tomas Vortuba has continued his series looking at building command line tools with PHP and the Symfony Console component. In this latest post he shows how to create an application using dependency injection in just four files.

Series about PHP CLI Apps continues with 3rd part about writing Symfony Console Application with Dependency Injection in the first place. Not last, not second, but the first. Luckily, is easy to start using it.

He starts with a bit of information about how Symfony has evolved from the previous method of using controllers as services to create CLI tools. Now commands can be used as services and be pushed into/pulled from a dependency injection container. He then walks through the three steps to adding a command as a service:

1. updating the services.yml file to include linking for the console application class.
2. updating the Kernel to load the yml configuration.
3. creating the bin file to execute the application.

With this structure in place, he then shows how to share functionality between services using a CompilerPass.