Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

s, the term ''wheel'' refers to a

user account A user is a person who utilizes a computer or network service. A user often has a user account and is identified to the system by a username (or user name). Other terms for username include login name, screenname (or screen name), accoun ...

with a ''wheel bit'', a system setting that provides additional special system privileges that empower a user to execute restricted

command Command may refer to: Computing * Command (computing), a statement in a computer language * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on Apple Macintosh computer keyboards * ...

s that ordinary user accounts cannot access.

Origins

The term ''wheel'' was first applied to computer user privilege levels after the introduction of the TENEX

, later distributed under the name

TOPS-20 The TOPS-20 operating system by Digital Equipment Corporation (DEC) is a proprietary OS used on some of DEC's 36-bit mainframe computers. The Hardware Reference Manual was described as for "DECsystem-10/DECSYSTEM-20 Processor" (meaning the DEC PDP- ...

in the 1960s and early 1970s. The term was derived from the slang phrase '' big wheel'', referring to a person with great power or influence. In the 1980s, the term was imported into

culture due to the migration of operating system developers and users from TENEX/TOPS-20 to Unix.

Wheel group

Modern Unix systems generally use

user groups Ancient Egyptian roles * User (ancient Egyptian official), an ancient Egyptian nomarch (governor) of the Eighth Dynasty * Useramen, an ancient Egyptian vizier also called "User" Other uses * User (computing), a person (or software) using an ...

as a

security Security is protection from, or resilience against, potential harm (or other unwanted coercive change) caused by others, by restraining the freedom of others to act. Beneficiaries (technically referents) of security may be of persons and social ...

protocol to control access privileges. The ''wheel'' group is a special user group used on some Unix systems, mostly

BSD The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berk ...

systems, to control access to the su or

sudo sudo ( or ) is a program for Unix-like computer operating systems that enables users to run programs with the security privileges of another user, by default the superuser. It originally stood for "superuser do", as that was all it did, and it i ...

command, which allows a user to masquerade as another user (usually the

super user Stack Exchange is a network of question-and-answer (Q&A) websites on topics in diverse fields, each site covering a specific topic, where questions, answers, and users are subject to a reputation award process. The reputation system allows th ...

). Debian-like operating systems create a group called sudo with purpose similar to that of a ''wheel'' group.

Wheel war

The phrase wheel war, which originated at

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

, is a term used in

computer culture Internet culture is a culture based on the many way people have used computer networks and their use for communication, entertainment, business, and recreation. Some features of Internet culture include online communities, gaming, and social med ...

, first documented in the 1983 version of

The Jargon File The Jargon File is a glossary and usage dictionary of slang used by computer programmers. The original Jargon File was a collection of terms from technical cultures such as the MIT AI Lab, the Stanford AI Lab (SAIL) and others of the old ARPANET A ...

. A 'wheel war' was a user conflict in a

multi-user Multi-user software is computer software that allows access by multiple users of a computer. Time-sharing systems are multi-user systems. Most batch processing systems for mainframe computers may also be considered "multi-user", to avoid leaving t ...

(''see also: multiseat'') computer system, in which students with administrative privileges would attempt to lock each other out of a university's computer system, sometimes causing unintentional harm to other users.

References

{{Reflist Unix Computer jargon