This directory of Linux commands is from Linux in a Nutshell, 5th Edition.
Click on any of the 687 commands below to get a description and list of available options. All links in the command summaries point to the online version of the book on Safari Bookshelf.
su [option] [user] [shell_args]
Create a shell with the effective user ID user. If no user is specified, create a shell for a privileged user (i.e., become a superuser). Enter EOF to terminate. You can run the shell with particular options by passing them as shell_args (e.g., if the shell runs bash, you can specify -c command to execute command via bash, or -r to create a restricted shell).
Become root and obtain all of root's user environment:
$ su -
Become root long enough to restart the Apache httpd web server, then revert to the current user:
$ su -c /etc/rc.d/init.d/httpd restart