Editing Su (Unix) (section)

{{Short description|Standard UNIX utility}}
{{lowercase title}}
{{Infobox software 
| name                   = su
| logo                   = 
| screenshot             = Su on Linux screenshot.png
| screenshot size        = 
| caption                = 
| author                 = {{Plainlist|
* [[Dennis Ritchie]]
* [[Ken Thompson]]
}}
| developer              = [[AT&T Bell Laboratories]]
| released               = {{Start date and age|1971|11|3}}
| latest release version = 
| latest release date    = 
| operating system       = [[Unix]] and [[Unix-like]]
| genre                  = [[Command (computing)|Command]]
| license                = 
| website                = 
}}
The [[Unix]] command '''{{mono|su}}''', which stands for "substitute user"<ref>{{Cite web
 | url         = https://man7.org/linux/man-pages/man1/su.1.html
 | title       = su(1) - Linux manual page
 | date        = April 2, 2021
 | quote       = {{Mono|su - run a command with substitute user and group ID}}
}}</ref><ref>{{Cite web
 | url         = https://s3.amazonaws.com/plan9-bell-labs/7thEdMan/v7vol1.pdf
 | title       = Unix Programmer's Manual, Seventh Edition, Volume 1
 | page        = 174
 | date        = January 1, 1979
 | url-status  = live
 | archive-url = https://web.archive.org/web/20220120180645/https://s3.amazonaws.com/plan9-bell-labs/7thEdMan/v7vol1.pdf
 | archive-date= Jan 20, 2022
 | quote       = {{mono|su - substitute user id temporarily}}
}}</ref> (or historically "superuser"<ref>{{cite web
 | url         = https://www.bell-labs.com/usr/dmr/www/man13.pdf
 | title       = Unix Programmer's Manual
 | date        = November 3, 1971
 | page        = 17
 | url-status  = live
 | archive-url = https://web.archive.org/web/20220317213155/https://www.bell-labs.com/usr/dmr/www/man13.pdf
 | archive-date= March 17, 2022
 | quote       = {{mono|su -- become privileged user... su allows one to become the super-user.}}
}}</ref><ref>{{cite web
 | url         = https://www.bell-labs.com/usr/dmr/www/pdfs/manindex.pdf
 | title       = Unix Programmer's Manual - Table of Contents
 | date        = November 3, 1971
 | url-status  = live
 | archive-url = https://web.archive.org/web/20220317213356/https://www.bell-labs.com/usr/dmr/www/pdfs/manindex.pdf
 | archive-date=March 17, 2022
 | quote       = {{mono|su: become super-user}}
}}</ref>), is used by a computer user to execute commands with the privileges of another user account. When executed it invokes a [[shell (Unix)|shell]] without changing the current working directory or the user environment.

When the command is used without specifying the new user id as a [[Command line#Arguments|command line argument]], it defaults to using the [[superuser]] account (user id 0) of the system.