su (Switch User): Su is a Linux command which allows you to switch the user you are logged in as. If invoked without a parameter, it attempts to switch to the root user account. It will prompt you for the password.

To switch back to your own user account (or any other account), you must specify your username (e.g., su user01), but under certain circumstances it will not ask you for the password. (For example, if you are in kde and use su to switch to root from a konsole, when you switch back you will not have to enter your password.)

Some people call this command, or the user invoked by this command, the "superuser" but I prefer not to use that terminology. The user invoked is "root" and it's just misleading to think there is something out there called the superuser. Also, note that you can su to any userid (as long as you specify it). Just my $.02

See also:

• Owner
• sudo
• suid
• suexec

Contributors

• RandyKramer - 31 Jan 2002
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