[mythtv-users] Shutdown / Restart Frontend

[Nicolas Krzywinski]

Am 14.12.2014, 05:31 Uhr, schrieb <mythtv-users-request at mythtv.org>:

> Message: 21
> Date: Sun, 14 Dec 2014 05:30:44 +0100
> From: Hika van den Hoven <hikavdh at gmail.com>
> To: Discussion about MythTV <mythtv-users at mythtv.org>
> Subject: Re: [mythtv-users] Shutdown / Restart Frontend
> Message-ID: <10710665481.20141214053044 at gmail.com>
> Content-Type: text/plain; charset=us-ascii
> [..]
> My big question already for some time is: 'how do WM's then manage to
> stop/reboot on user accounts? Without any sudo settings?
> I guess that in this procedure used by WM's something is going wrong.
> Tot mails,
>   Hika
 From my experience:
The window manager checks if other users are logged in to the system. If  
any (including shell logins!), it denies to shut down or restart for any  
such a request from within the wm gui elements - it automatically logs out  
the current user, instead.

 From my theory:
To be able to execute root restricted tasks like e. g. shutdown and  
restart, the window manager either does have to execute them as root, or  
being allowed to do this by an exceptional rule via sudoers. Due to the  
fact, that sudoers rules seem to only scope on users or groups (and not e.  
g. processes) and one can see window manager processes running by root, I  
assume that those processes actually execute a reboot/shutdown, while  
being triggered by the user specific wm processes.
For sure, the above theory was not described technically correct, but may  
give an idea of how it could work in a logical manner. When referenced to  
window manager, I simply did not distinguished between the real wm and the  
greeter/login manager (or how this guy is called... :D) for example -  
which may be the combination of lightdm and gnome or many others...

-- 
Erstellt mit Operas E-Mail-Modul: http://www.opera.com/mail/