Wheel (Unix term)

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For this concept applied to Wikipedia, see Wikipedia:Wheel warring.

In computing, the term wheel refers to a user account with a wheel bit, a system setting that provides additional special system privileges that empower a user to execute restricted commands that ordinary user accounts cannot access.[1][2] The term is derived from the slang phrase big wheel, referring to a person with great power or influence.[1] It was first used in this context with regard to the TENEX operating system, later distributed under the name TOPS-20 in the 1960s and early 1970s.[2][3]

The term was adopted by Unix users in the 1980s, due to the movement of operating system developers and users from TENEX/TOPS-20 to Unix.[2] Modern Unix implementations generally include a security protocol that requires a user to be a member of the wheel user privileges group in order to gain superuser access to a machine by using the su command.[1][2][4]

Wheel group[edit]

Modern Unix systems use user groups to control access privileges. The wheel group is a special user group used on some Unix systems to control access to the su command, which allows a user to masquerade as another user (usually the super user).


  1. ^ a b c "Wheel". Jargon File 4.2.0. Dictionary.com. Retrieved 2008-09-12. 
  2. ^ a b c d "Wheel bit". Jargon File 4.2.0. Dictionary.com. Retrieved 2008-09-12. 
  3. ^ "TWENEX". Jargon File 4.4.7. Eric Raymond. Retrieved 2008-09-12. 
  4. ^ Levi, Bozidar (2002). UNIX Administration: A Comprehensive Sourcebook for Effective Systems and Network Management. CRC Press. p. 207. ISBN 0-8493-1351-1.