[TriLUG] running script as mail alias, script running as specific user

[Jeremy P]

On Mon, 14 Jan 2002, Jon Carnes wrote:

> I'm trying to setup an automated process using a email address.  The email
> alias is something like:
>   thetrees:  "|/usr/local/sbin/thetrees"
>
> The script thetrees in /usr/local/sbin needs to run as a specified user.
> The user should be "lorax".  How do I let the lorax speak for thetrees?

ISTR you use sendmail.  If so, you'll need to put the script in /etc/smrsh
(or at least put a symlink there).  Then, in the alias file call it
something like "|/etc/smrsh/thetrees".  By default, the script will run as
user "mail".

> I've tried using chmod u+s on the script, and setting the user to lorax, but
> that is not working.

The kernel disallows suid shell scripts.

You might be able to setup something with "sudo" (to allow uid mail to run
something as lorax).  But I don't know if there's a way of stopping sudo
from asking for the user's password.  You could always rewrite your script
in C, and then suid that C program.  You could also have it check to be
sure it was started as "mail" so no one else can invoke it.  But this gets
complicated!

--Jeremy