Caution: This version of this document is no longer maintained. For the latest documentation, see http://www.qnx.com/developers/docs.

su

Switch user ID (UNIX)

Syntax:

su [-c] [[-] userid [arguments]]

Runs on:

Neutrino

Options:

-c
Pass the specified list of arguments to the shell.
userid
Switch to the specified user ID. If preceeded by the - argument, userid's login scripts will run, setting up the shell environment as if you had actually logged in as the specified user.

Description:

The su utility lets you temporarily become another user, then return to your regular userid.

The su utility requests the password of the given userid (root, by default) and changes to that userid, invoking its shell but modifying only essential elements of the environment. Only the HOME, PATH, and possibly SHELL environment variables are changed, but the new shell has the rights and privileges of the user specified. The new userid remains in effect until this shell exits.


Note: This utility needs to have the setuid ("set user ID") bit set in its permissions. If you use mkefs, mketfs, or mkifs on a Windows host to include this utility in an image, use the perms attribute to specify its permissions explicitly, and the uid and gid attributes to set the ownership correctly.

Files:

/bin/sh
Korn shell command interpreter.
/dev/null
The bit bucket.
/etc/.pwlock
This file is used to lock password files when modifications are taking place.
/etc/acclog
Logs system accounting information.
/etc/default/profile
The passwd utility copies this file as a user's initial .profile when it creates a new account.
/etc/group
Defines the known groups for the system.
/etc/passwd
Defines the valid user IDs on the system.
/etc/shadow
Contains encoded versions of the actual passwords for user accounts. The passwords themselves aren't stored in the /etc/passwd file.
/usr/adm/sulog
Records all su activity.

See also:

login, passwd

Logging In, Logging Out, and Shutting Down in the Neutrino User's Guide