Erik: Copy from old

2009-06-06T23:31:33Z

Copy from old

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Sudo is a program that lets a certain user run a program as root or another user. For instance say you want to let a user run 
/usr/sbin/alsactl with root privilege , but not give them your root password? In sudo you can do
this! First su into root and type:

visudo

You will now see a few example lines, Now first lets make the user "sandman1" be able to run alsactl as root:

sandman1 ALL = /usr/sbin/alsactl

Now of course you change the values of the following above. The first value "sandman1" is of course the username.
the ALL is the hostname, now you can actually put the real host name there , or you can allow a user to be on any host by adding ALL. Now log into the user and type the following:

sudo /usr/sbin/alsactl

This command will ask you for a password, type YOURS in and not root
and boom, you now can run /usr/sbin/alsactl as root. With sudo you can
also run programs as a different username besides root:

sandman1 192.168.0.2 = (test) /usr/sbin/alsactl

Now you noticed that I used an actual IP address in this
example. (That is my local IP anyways) Now you noticed the (test) that
is the username that it will run as if i type the following command:

sudo -u test /usr/sbin/alsactl

Now the following example makes it so you do not have to type any
password in:

%wheel ALL = NOPASSWD: /usr/sbin/alsactl

The % symbolizes that wheel is not a user, but a group. Now if you are
in the group wheel and type "sudo /usr/sbin/alsactl", you will notice
that it did not ask you for the password! Now all of this is great,
but what happens when you have more than 1 user that is not in the
same group, but want to run the same command as root?

User_Alias GROUPOFUSERS = sandman1, sandy
GROUPOFUSERS ALL = NOPASSWD: /usr/sbin/alsactl

Now the 2 users sandman1, and sandy can run /usr/sbin/alsactl as
root! Now see how easy it is to add multiple users? You can also add
multiple Hosts as well:

Host_Alias SWEETHOST = 192.168.0.2, 192.168.0.3
sandman1 SWEETHOST = NOPASSWD: /usr/sbin/alsactl

Now you see how easy it is to setup multiple hosts? Now to find out
what commands you can run using sudo just type the following command:

sudo -l

That will list all the commands you are aloud to run! Now sudo is an
easy tool and I hope you have a great time using it.

[[Category:Tutorials]]

Sudo - Revision history

Erik: Copy from old