TTY Pty PTS II

[-] Historical TTY Terminal virual console Terminal emulator Pseudo Terminal Linux terminal equipment List A table reference to organize, the content will not be very accurate, not too rigorous.

Tty	Teletypewriter (Telex typewriter)	Terminal Equipment (Terminal)
Pty	Pseudo TTY	Pseudo Terminal
Pts	pseudo-terminal slave
Ptmx	Pseudo-terminal Master Multiplexer

history.

TTY ==> refers to all terminals (Terminal) TTY

It is the abbreviation of teletype (or teletypewriter), Chinese translation: Telex typewriter.

A typewriter usually consists of a keyboard, a transceiver, and a printing mechanism. Telex printer is a relatively early appearance of the product, for the fax machine in general use of the previous communication equipment, the principle of using a bit approximate telegraph. It can be installed in the office, so there is no need to go to the Telegraph offices to generate electricity. Terminal

A terminal, an electronic or electromechanical hardware device that is used to input data to a large host and display data from the host.

In order to fully use the computing resources provided by the computer, many of the early computers connected to a number of terminal consoles, these terminals from the hardware structure is very simple, do not perform the task of computing, simply send the user's input to the main computer to deal with, and then return the calculation results to the user.

The front telex was the first computer terminal. Replaced by the monitor and keyboard. They are connected to the host via a serial port (usually RS232). Sub-mute terminals (dumb terminal) and intelligent terminals (start terminal). or a thin client (thin client), or FAT clients.

Into the PC era, the monitor no longer contains character-generated hardware, and all video signals are generated by the graphics card located inside the PC. At this time the monitor is no longer a terminal, when the PC linked to a large host, you can simulate the terminal (such as through Telnet) virual console

Virtual Console (VC), or virtual terminal. It is a conceptual combination of the computer user interface keyboard and display (is a conceptual combination of the keyboard and display for a computer user interface.).

It is a feature of Unix-like systems. For example, under Linux, through

Ctrl+alt+f1~6

You can switch between six virtual consoles. terminal emulator

With the wide use of the X Windows system, the use of virtual consoles is becoming less and fewer, and the console program can be run in the Terminal Simulator (terminal emulator).

These are called Pseudo terminals (Pseudo Terminal) Pseudo Terminal

Pseudo terminal is a pseudo device pair. There are two kinds of naming styles

BSD Ptys (OBSOLETE)	Slave	/DEV/TTY[P-ZA-E][O-9A-F]
Master	/DEV/PTY[P-ZA-E][0-9A-F]
Unix98 Ptys	Slave	/dev/pts/n
Master	/dev/ptmx

Linux TerminalVirtual Console (dummy console)

Under Linux, switch to the Virtual Console via Ctrl+alt+f1~6, and run TTY and Stty to see

debao@ubuntu:~$ TTY
/dev/tty1
debao@ubuntu:~$ stty
speed 38400 baud; line = 0; 

Console devices

Select Single user mode when system is started

debao@ubuntu:~$ TTY
/dev/console

Serial

This thing is so complicated.

Normal serial port	/dev/ttys[0~191]
Serial Mux Device	/dev/ttyb[0~]
Chase serial Card (OBSOLETE	/dev/ttyh[0~]
Cyclades serial card	/DEV/TTYC[0~31]
Digiboadr serial card	/dev/ttyd[0~] td>
Stallion serial card	/dev/ttye[0~63,64~127,...]
Specialix serial card	/dev/ttyx[0~]
Isdn4linux Virtual Modem	/dev/ttyi[0~63]