Administrative Access

In a systems administrator role, it is often necessary gain administrative privledges as the root user. There a couple way to achieve this.


The su command can be used to become the root user.


run a shell with substitute user and group IDs


su [-] [USER]

-, -l, --login

make the shell a login shell

If the USER name is left off, attempt to become root. Unix system administrators seldom login as root. Rather, they usually login to the system as themselves and then use su - or sudo to gain superuser (root) privileges.

The root user may su to other user accounts without typing a password. Other users must always enter the correct password when using su.



sudo allows a permitted user to execute a command as the superuser or another user, as specified by the security policy.

See also

Sudo Main Page