To use sudo on the command line, preface the command with sudo, as below: Example #1
sudo chown bob:bob /home/bob/*
sudo /etc/init.d/networking restart
To repeat the last command entered, except with sudo prepended to it, run:
Allowing other users to run sudo
sudo adduser <username> sudo
where you replace <username> with the name of the user (without the <>).
In previous version of Ubuntu
sudo adduser <username> admin
would have been appropriate, but the admin group has been deprecated and no longer exists in Ubuntu 12.04.
Logging in as another user
Please don't use this to become root, see further down in the page for more information about that.
sudo -i -u <username>
For example to become the user amanda for tape management purposes.
sudo -i -u amanda
The password being asked for is your own, not amanda's.
Enabling the root account
Enabling the root account is rarely necessary. Almost everything you need to do as administrator of an Ubuntu system can be done via sudo or gksudo. If you really need a persistent root login, the best alternative is to simulate a root login shell using the following command...
To enable the root account (i.e. set a password) use:
sudo passwd root
Use at your own risk!
Logging in to X as root may cause very serious trouble. If you believe you need a root account to perform a certain action,please consult the official support channels first, to make sure there is not a better alternative.
Re-disabling your root account
If for some reason you have enabled your root account and wish to disable it again, use the following command in terminal...
sudo passwd -dl root
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