Fwd: [xubuntu-users] Replacing LightDM with XDM

George F. Nemeyer tigerwolf at tigerden.com
Wed Nov 27 07:41:10 UTC 2013

On Tue, 26 Nov 2013, Stephen Michael Kellat wrote:

> The last time anything happened in Ubuntu's archives with XDM was a
> merge done by Micah Gersten in December 2011.  The screenshots in the
> packages.ubuntu.com listing show the Debian graphic very prominently so
> we'll need to see if that is hard-coded or not.

The graphic isn't hardcoded.  At least isn't now or in older XDM
setups I've done on other distros in the past.  In 13.04, it's specified
in /etc/X11/xdm/Xresources with parameter
   xlogin*logoFileName: <path to the.graphic.xpm file>)

Likewise, the text portions of the login screen can be set with
   xlogin*greeting: CLIENTHOST -- Login as guest.  No Password.  (<--ours)
   xlogin*namePrompt: \040\...\040Login:      (<--default)
   xlogin*fail: Login incorrect or forbidden by policy    (<--default)

Apparently the "Password:" prompt text comes from PAM, and in 13.04 the
prompt and entry box only appear after a username is entered.  (In a much
older Vector Linux (slackware-based) I used, the Password: line was always

In 13.04, an .Xsession file containing "exec xfce4-session" is required in
the user's home directory, otherwise it tries (and fails) to launch a
gnome session.

> From the discussion on LP Bug #585853 it looks like Steve Langasek said
> XDM does not play nice with Upstart ten months prior to Micah's merge.
> Debian Bug #615020 talks about a lack of ConsoleKit support which is
> going to be crippling nowadays.  More details can be found through the
> portal here: http://packages.qa.debian.org/x/xdm.html

I'm not a developer, or a programmer.  I'm a hardware type, but I've poked
at linux since 0.93 as an admin...and the bulk of my experience goes back
to days when things were lots less convoluted with PAM, policykit,
consolekit, hal, upstart, dbus...most of which I know nothing at all about
and a lot of which tends to make my head hurt!  I see there was some
comment on the bug you mentioned there were some patches for KDM in
Mandriva but they didn't get upstream.  Plus the discussion is pretty old,
so don't know if any of that would even be relevant to the current

> I might suggest considering a different option than XDM if possible.  I
> might think of some Wednesday once I get a good night's sleep after a
> day On The Run in Cleveland handling business downton.

I'm open to an alternative provided:

 --  It's simple to configure (so I don't have to re-invent the wheel
 --  It has documentation that a clueless old guy like me can decipher
 --  It doesn't drag in a lot of extra baggage needed to make it work
 --  It will allow XFCE to function and not force a window manager
     change (users are familiar with XFCE, and I've made the new machines
     look and feel like our old ones as much as possible, and a kiosk
     mode is *essential* to restrict what random users can
     do/change/screw up)
 --  It will (preferably) allow a remote X login like VNC from the
     system admin.
 --  It will allow a custom background and logo graphic(s) for the
     greeter login screen as well as enough text to inform someone
     who has never seen it before to be able to do a guest login.
 --  It is or can be 'dumbed down' to not allow the public users to
     do *anything* other than log in to the guest account.  And, of
     course, it should also allow proper users with greater privileges
     to log into their individual accounts as well.
     i.e. The login screen should allow
          No shutdown/sleep/reboots
          No network or any other system configuration/changes.
          No language, or session selection/changes.

I do appreciate folks looking at this, and I'm happy to be a guinea pig
for suggestions or testing, though I may need some hand-holding for
anything very complex.

Thanks again!

=^_^=  Tigerwolf

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