Summary
A CLI (Command Line Interface) is a text-based user interface where users interact with a program by typing commands, as opposed to using a graphical user interface (GUI).
What is a CLI?
A CLI allows users to issue instructions to a computer program by typing text commands into a terminal or console. The program reads the input, executes the corresponding action, and typically returns text output. CLIs have been the primary interface for operating systems and development tools since the earliest computers.
In modern development and operations, CLIs are the standard way to interact with cloud platforms, container orchestration systems, version control, and CI/CD tools. Examples include kubectl for Kubernetes, git for version control, aws for AWS, and terraform for infrastructure provisioning.
CLIs are scriptable, composable, and automation-friendly, which makes them preferable over GUIs for repetitive tasks, pipeline steps, and remote server management.
Why is a CLI relevant?
- Automation: CLI commands can be scripted and integrated into pipelines, enabling repeatable and consistent operations
- Efficiency: Experienced users can perform complex tasks faster via keyboard commands than through a GUI
- Remote access: CLIs work over SSH connections and in headless environments where no graphical interface is available