Introduction

In this section you will find documentation on how to use the Unix command-line interface Bash.

The command-line interface (CLI) is an alternative to the graphical user interface (GUI) that you probably know better. Both let you work with your computer, but in different ways:

• In a GUI, you click on buttons, open folders and use menus.
• In the CLI, you type text to give commands (instructions to the computer), and you see the result as text.

When people talk about the CLI, you will hear the words terminal, shell and prompt. They are related, but they are not the same:

• The terminal is the window in which you type commands. It is sometimes also called a console.
• The shell is the program that reads the commands you type in the terminal and tells the operating system what to do. There are several shells, for example bash (short for Bourne Again Shell) and zsh. They use slightly different rules, but the basic commands are the same. These pages use bash.
• The prompt is the text that the shell shows when it is ready for your next command. It often shows your user name, the name of your computer and the folder you are in. It usually ends with a $ sign, for example user@laptop:~$.

These pages are a reference: they list the key commands, including more complex ones, with short examples. If you have never used the command line before, start with the Getting started with bash and an HPC tutorial, which explains each step in more detail.