Graphical Display Managers

[Constantinos Maltezos]

On Sunday 27 April 2008 8:45:48 D. Michael McIntyre wrote:
> > What is the difference
> > between typing KDM/GDM/XDM at the command prompt and typing startx at
> > the command prompt?
>
> If you type kdm or gdm or xdm at the command prompt, I don't think any of
> them will work.  You should use /etc/init.d/kdm | xdm | gdm to start these.

I can't get to a console terminal without video corruption on my Kubuntu 
machine, so of course I can't test it, but in the other distro I have and in 
every other flavor of Linux I've used, simply typing the name of the display 
manager at the console will start that selected display manager *as long as 
you are logged in as root* - which, of course, you can't in Kubuntu, so maybe 
I don't have a point there.  Except you can still probably still do it with 
sudo.

> The main practical difference between using one of these and just running
> startx is what kind of background you get behind your splash screen.  On a
> typical KDM-based setup logging into a KDE session, you get a nice
> wallpaper behind the "KDE is starting up" display.  If you use startx, you
> get a plain gray background instead. That's the biggest difference, really.
>  There might be some other, more subtle differences with respect to
> environment variables and so on.

This is true, but you left out the fact that "startx" will only start the 
graphical interface for the user you're logged in as in the console, while 
the display managers (kdm/gdm/xdm) act as login screens similarly to the 
console login prompt.  You choose what user you want from that point and it 
loads the selected environment.

Also... to the original poster, as you know, you can choose which window 
manager to log into via the menu.  If you use "startx", you have to add the 
wm binary and it's full path to launch a certain wm.  For instance, if I want 
to start X with icewm managing the windows, I type "startx /usr/bin/icewm".  
Typing it without an argument always gives you the default.