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This article will explain in detail what the linux console refers to. The editor thinks it is very practical, so I share it with you as a reference. I hope you can get something after reading this article.

The linux console is an end device or software that displays linux system messages. Linux defaults that all virtual terminals are consoles, which can display system messages, and can also be called consoles for programs that are specially used to simulate terminal devices, such as "gnome-terminal", "mlterm" and so on.

The operating environment of this tutorial: linux5.9.8 system, Dell G3 computer.

Terminal Terminal

Definition of terminal

(1) what is terminal?

A terminal is a set of equipment that processes the input and output of the host computer, which is used to display the output of the host operation and accept the input required by the host. Typical terminals include display keyboard kit, printer typewriter kit and so on.

(2) the essence of the terminal.

In fact, it is basically a word, can accept input, can display output, this is enough, no matter what era, the terminal always plays the role of man-machine interface, the so-called Terminal, that is, the edge of the machine!

As long as it can provide input and output functions to the computer, it is a terminal, regardless of its location.

Classification of terminals

Local terminal

A display / keyboard combination that connects the host to the monitor with VGA and the host to the keyboard with PS/2 or USB is a local terminal.

Remote terminal connected by serial port

Connect the host to another host with a monitor and keyboard via a serial cable, and lend that host's monitor and keyboard to the serial counterpart by running a terminal emulation program, such as Windows HyperTerminal.

Remote terminal carried by TCP/IP

Something like Telnet,SSH.

The first two categories are also called "physical terminals", and the latter are called "pseudo terminals".

Roughly speaking, let's start with these categories. It can be seen that of the above three categories, the first two are directly related to physical devices locally, such as VGA port, PS/ port 2, serial port, and so on. This kind of terminal is called physical terminal, while the third type is not associated with any physical equipment locally. Be careful, do not regard the physical network card as the physical device associated with the terminal, it is only the physical equipment associated with the tunnel, and the physical network card here can be changed into a truck. They are not directly related to terminals, so these terminals that are not directly related to physical devices are called pseudo-terminals.

Console Console

What is a console?

The terminal that displays the system message is called the console, and Linux defaults that all virtual terminals are the console, which can display the system message.

In addition, for those programs specially used to simulate terminal devices, we can also call them console Console, and software such as gnome-terminal,urxvt,mlterm,xterm can be called console.

Summary: the console is a special case of the terminal and a true subset of the terminal. It is a virtual terminal.

The distinction between the terminal and the console

Physical terminal: a monitor, keyboard and mouse directly connected to the host computer. In the actual rack server deployment, it is generally multiple servers to share a set of terminals, referred to as KVM (Keyboard keyboard, video monitor, mouse mouse)

Virtual terminal (tty): it is attached to the physical terminal and implemented in a software way. CentOS enables 6 virtual terminals by default, which can be switched by shortcut keys. The switching mode is: Ctrl-Alt-F [1Mel 6], the corresponding file is / dev/tty#.

You can view the current virtual terminal number with the tty command. Tty is the abbreviation of teletype writer.

Pseudo terminal (pty): two application scenarios

(1) the first command line interface opened under the graphical interface, the one we often open with Ctrl+Alt+T is actually a pseudo terminal.

(2) the command line interface opened remotely based on ssh protocol or telnet protocol is the most commonly used way for operation and maintenance engineers to connect to the server. Pts (pseudo-terminal slave) is the implementation method of pty.

Summarize three viewpoints:

(1) the console is a true subset of the terminal

(2) tty2-tty6, these five black interfaces are virtual terminals, and they are real consoles. At this time, the five virtual terminals are called consoles.

(3) what is opened under the desktop through Ctrl+Alt+T is a pseudo terminal, and a pseudo terminal that is remotely connected through Telnet or ssh is also created.

Description: the difference between console and terminal has been completely watered down in linux

This is the end of the article on "what the linux console refers to". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

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