Getty (Unix)
Encyclopedia
getty, short for "get teletype", is a Unix
program running on a host computer that manages physical or virtual terminals
(tty
). When it detects a connection, it prompts for a username and runs the 'login
' program to authenticate the user.
Originally, on traditional Unix systems, getty handled connections to serial terminals (often teletype machines) connected to a host computer. The 'tty
' part of the name stands for teletype, but has come to mean any type of text terminal. One getty process serves one terminal. In some systems, for example Solaris, getty was replaced by ttymon.
Personal computer
s running Unix-like operating system
s, even if they do not provide any remote login services, may still use getty as a means of logging in on a local virtual console.
Instead of the 'login' program getty may also be set up by the system administrator
to run any other program, for example a PPP
daemon
to provide dial-up Internet access.
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
program running on a host computer that manages physical or virtual terminals
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...
(tty
TTY
TTY may stand for:* Teleprinter or Teletypewriter or Teletype Printer, a typewriter paired with an electronic communication channel, used for telecommunications or as a computer terminal....
). When it detects a connection, it prompts for a username and runs the 'login
Logging (computer security)
In computer security, a login or logon is the process by which individual access to a computer system is controlled by identifying and authentifying the user referring to credentials presented by the user.A user can log in to a system to obtain access and can then log out or log off In computer...
' program to authenticate the user.
Originally, on traditional Unix systems, getty handled connections to serial terminals (often teletype machines) connected to a host computer. The 'tty
TTY
TTY may stand for:* Teleprinter or Teletypewriter or Teletype Printer, a typewriter paired with an electronic communication channel, used for telecommunications or as a computer terminal....
' part of the name stands for teletype, but has come to mean any type of text terminal. One getty process serves one terminal. In some systems, for example Solaris, getty was replaced by ttymon.
Personal computer
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
s running Unix-like operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
s, even if they do not provide any remote login services, may still use getty as a means of logging in on a local virtual console.
Instead of the 'login' program getty may also be set up by the system administrator
System administrator
A system administrator, IT systems administrator, systems administrator, or sysadmin is a person employed to maintain and operate a computer system and/or network...
to run any other program, for example a PPP
Point-to-Point Protocol
In networking, the Point-to-Point Protocol is a data link protocol commonly used in establishing a direct connection between two networking nodes...
daemon
Daemon (computer software)
In Unix and other multitasking computer operating systems, a daemon is a computer program that runs as a background process, rather than being under the direct control of an interactive user...
to provide dial-up Internet access.
See also
- setterm
- sttySttyThe Unix stty command is used for changing the settings of a Unix computer terminal. This command is used to change keystrokes, irregular character handling, and more. Stty gives a full set of features that are also available in ncurses for programmers but simplifies it by building it in to a...
- tset
- ttyTty (Unix)tty is a Unix command that prints to standard output the name of the terminal connected to standard input. The name of the program comes from teletypewriter, abbreviated "TTY".When the program runs, it will output something like this:$ tty/dev/pts/4...
External links
- getty - BSD Unix man page
- ttymon - Solaris man page
- agetty(8) - alternative LinuxLinuxLinux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
agetty - mgetty(8) - mgetty (modem aware getty)
- mingetty(8) - mingetty (minimal getty)
- ngetty - minimal getty (one process controls all ttys)
- Qingy - Qingy Is Not GettY
- vgetty an extension to mgetty