What Is Terminal In Linux? | Components, Types​​ & Standard Commands

A terminal, also known as a shell, is a program that allows users to interact with their operating system through a command-line interface. It provides a way for users to execute commands, navigate files, install software packages, and perform various tasks on their system without the need for a graphical user interface (GUI). In Linux, the default terminal emulator is called "Bash," which stands for Bourne-again shell.

A terminal window typically consists of a command prompt, which is where you enter commands, and a text area where the output of those commands is displayed. You can use the terminal to run commands, execute scripts, navigate the file system, manage processes, and perform other system administration tasks. It provides direct access to the underlying operating system and can be used to perform a wide range of tasks.

Additionally, the terminal in Linux provides a way for users to automate repetitive tasks by creating scripts and running them from the command line. This can be useful for system administrators and power users who need to perform complex tasks on a regular basis. Overall, the terminal in Linux is an essential tool for any user who wants to fully control and manage their system using text commands. In this article, we are going to discuss the various components, types of Linux terminals, and some commonly used commands.

Components of a Linux Terminal

The following are the components of a terminal in Linux:

1. Shell: The shell is a command-line interpreter that processes the commands entered by the user and executes them.

2. Terminal Emulator: It is a program that emulates a physical terminal in the system along with providing a GUI to interact with the shell and run commands. It offers several advantages over physical terminals, including the ability to customize the font and color scheme, check for an error message, and other settings like reproducing a video terminal. They also provide users with the ability to copy and paste text in the executable files, scroll through the binary program, background transparency and resize the window terminal application.

3. Prompt: The prompt is a symbol or text string that indicates the readiness of the shell to accept a command. It usually includes the current working directory, username, and hostname.

4. Command Line: The command line is the area where the user types command to interact with the shell.

5. Standard Input/Output/Error: The standard input/output/error (stdin, stdout, stderr) are the streams through which the shell communicates with the user and the system. The standard input (stdin) accepts input from the user, the standard output (stdout) displays output to the user, and the standard error (stderr) displays error messages.

6. History: The history feature allows the user to view and recall previously executed commands.

7. Environment Variables: Environment variables are variables that contain information about the system and the user's environment. They can be used to customize the behavior of the shell and the programs that run within it.

8. Text Editor: A text editor is a program that allows the user to edit different text files. It can be used to create and modify configuration files, scripts, and other text-based documents.

Methods to open a terminal

To open the command line terminal in Linux, there are a few methods depending on the distribution and the desktop environment being used. In most cases, you can use one of the following methods:

1. Using the shortcut key: The most common way to open the terminal is by pressing the "Ctrl + Alt + T" keys simultaneously.

2. From the applications menu: Some Linux distributions have a terminal icon in the applications menu that you can click to open.

3. From the file manager: Some file managers in Linux, such as Nautilus have the option to open the terminal from the right-click menu.

Steps to check for an active user in the terminal

To check for an active user (normal user) in the Linux terminal, you can use the who command. The who command displays information about users who are currently logged in to the windows terminal.

Here's how to use the who command in the terminal session:

1. Open a terminal window

2. Type the following command: who

3. Press Enter

The who command will display a list of all current users on the system, along with some additional informational messages such as their login name, the terminal they are using, and the time they logged in to the input device.

Types of terminals in Linux

In Linux, there are several different types of special terminals available, each with its own features, capabilities, and configuration options. Here are some of the most commonly used types of terminals in Linux:

1. Virtual Terminal: A virtual terminal is a built-in feature of the Linux operating system that allows users to access multiple windows terminal sessions from a single physical console. Virtual terminals are accessed by pressing the Ctrl+Alt+F1 through Ctrl+Alt+F6 key combinations, opening a new virtual terminal on the console.

2. SSH Terminal: An SSH terminal is a type of terminal that allows users to access a remote server over a secure network connection. SSH terminals are commonly used by system administrators and developers to manage remote servers and run remote commands. Some popular SSH terminals in Linux include PuTTY, OpenSSH, and MobaXterm.

3. TTY Terminal: A TTY terminal is a type of windows terminal that is used to interface with the Linux kernel. TTY terminals are used to manage system resources and perform administrative tasks. TTY terminals are typically accessed by pressing Ctrl+Alt+F1 through Ctrl+Alt+F6 key combinations.

4. Serial Terminal: A serial terminal is a type of windows terminal used to communicate with devices over a serial port. Serial terminals are commonly used to manage embedded systems and other devices that do not have a graphical user interface.

5. GNOME Terminal: GNOME Terminal is a terminal emulator that is part of the GNOME desktop environment. The emulator for GNOME Terminal provides a graphical interface that allows you to run command-line utilities and graphical applications. It supports multiple tabs, profiles, configuration files, script files, and customization options, making it a popular choice among Linux users.

6. Konsole Terminal: Konsole is a terminal emulator that is part of the KDE desktop environment. Konsole provides a graphical interface that allows you to run command-line utilities in a graphical environment. It supports multiple tabs, profiles, and customization options, similar to GNOME Terminal.

In summary, the type of terminal the current user chooses to use in Linux depends on their preferences and requirements. TTYs and consoles are lightweight and fast but have limited functionality. X terminals (famous graphics terminals), SSH terminals, and desktop environment terminals like GNOME Terminal and Konsole provide a graphical interface and more features.

Standard commands used in the Linux terminal

Linux terminal provides powerful command-line user interaction to perform a wide range of tasks using different command options. Here are some basic options of commands used in Linux terminals:

Suggested reads:

1. Process Management In Linux | Stages, Types & Commands
2. What Is Linux Shell? Definition, Features, Types & More!
3. Linux File Permissions Simplified In This Complete Guide!
4. What Is Bash? Features, Major Concepts, Commands, & More!
5. Understanding Linux Zip Command With Examples