CLI

The term CLI, which stands for Command Line Interface, refers to a way of interacting with a computer via the entering written commands. Although we are now more accustomed to using graphical interfaces, the CLI remains essential for advanced programming, system administration and automation.

When a user works in a command-line interface, they enter text-based commands so that the the operating system carries out specific actions. From copying files to installing programmes or configuring networks, almost any task can be carried out via a CLI.

This environment, although less visually appealing than a graphical interface, offers more precise, faster and more direct control about the system. That is why it is a commonly used tool amongst developers, system administrators and advanced users.

What exactly is a CLI in computing?

A CLI is an environment in which users enter commands via a console or terminal. The system interprets those commands and executes them the tasks listed.

For example, instead of double-clicking to open a folder, in a CLI you would type something like ‘cd Documents’ to access it. This way of using the system requires knowledge of certain commands and their syntax, but it is extremely powerful once you’ve got the hang of it.

Unlike graphical user interfaces, which guide the user step by step, the CLI is text-based, and its use depends entirely on the user’s knowledge.

How does a CLI work?

The CLI follows a pattern It is quite clear and is based on the following steps:

1. Input (input): The user enters a written command.
2. Processing: The system analyses that command, checks that it is valid and carries out the corresponding action.
3. Output (output): The system displays a result on screen, which may be a message, an error, a list, a confirmation or a specific action.

For example, if a user types `mkdir new_folder`, the system will process that command and create a folder named «new_folder» in the current directory. If everything goes well, no message will be displayed; if there is an error, the system will indicate this.

The advantage of this environment is that enables tasks to be automated using scripts, working more quickly by chaining commands together, and accessing features that are sometimes not available via graphical interfaces.

Why is it useful to learn the CLI?

Although it isn’t essential for basic day-to-day tasks, understanding how a CLI works can open many doors in the world of computing.

• System administration: Many advanced configurations on Linux or servers are carried out exclusively via the command line.
• Automation: Creating scripts in Bash or PowerShell allows you to automate repetitive tasks such as backups, organising files or installing software.
• Efficiency: Running tasks from the CLI is usually quicker than navigating through menus and windows.
• Total control: The CLI provides detailed control over the system and its processes, making it ideal for professional environments.

In the world of servers, for example, much of the management is carried out without a graphical interface, so knowing how to use the command line is essential.