passwd

[Mindy Preston]

Gavin McDonald wrote:

>Ok, I'm a dummy for asking, I admit it.  Heck I even top-post!
>
>But "Why on Earth"(tm) would you want multiple user accounts
>to have the same UID, let alone the same UID of 0?!  UID is
>_user_ID_, right?  and UID 0 is Root, right?  
>
>  
>
UID in this case means the numerical user id, not the string associated 
with that UID.  It's counterintuitive that you would ever WANT to have 
two strings map to the same UID, but it does come in handy if you want 
to have more than one root password.  For example:

I install a machine called "gremlin".  I want to keep my root password 
secret, and I want to have it be the password for the user "root" on 
that machine.  The principal user, however, sometimes takes the machine 
out of the country, far beyond my reach.  She wants to be able to access 
the machine as super-user in case something goes wrong.  I create 
another account for her, say "jrandomgirl", and set the UID to be 0 in 
/etc/passwd.  She sets the password for jrandomgirl to be whatever she 
likes.  She can log in as jrandomgirl with the password of her choosing 
as the super-user.  I can log in as the user root with the password of 
MY choosing.

There are many more elegant ways to deal with this situation (sudo comes 
to mind), but this one is occasionally useful.

-Mindy Preston