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From: mouse@larry.mcrcim.mcgill.EDU
Newsgroups: comp.windows.x
Subject: Re:  xdm root window
Message-ID: <9101270342.AA27635@Larry.McRCIM.McGill.EDU>
Date: 27 Jan 91 03:42:38 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 41

> This should probably be a RTFM question, but I don't know which of
> TM's to FR.  So, I would appreciate hints as how to change the root
> window xdm displays.

(More text makes it clear he means the background to the login window.)

There is nothing that is obviously intended for this.  However, UTSLing
reveals that xdm uses xrdb to load resources just before creating the
login window and at no other time.  So, if you change your xdm-config
to run something else, that something else can set up the root
background.  For example, in xdm-config on one machine here I have

DisplayManager*xrdb:		/local/lib/X11/xdm/xrdb

where /local/lib/X11/xdm/xrdb is a shell script:

#! /bin/sh
# always called as $0 -display <disp> -load <file>
# we should parse the arglist, but not yet....
/local/bin/X11/xsetroot -solid black -display $2
/local/bin/X11/xrdb "$@"

This gives a solid black background for the login window (as one would
hope from the xsetroot arguments).

As the comments in the shell script imply, my example is very fragile:
it depends on xdm always running it with the arguments as commented
(determined by UTSLing).  I did this as an experiment to make sure it
works; if you are going to use this hack regularly I would definitely
urge you to have your replacement xrdb do a proper parse of its
argument list to figure out the display to use for the xsetroot (or
substitute).

X people, it might be nice to document this (or, preferably, provide a
somewhat less "magic" way of putting hooks before the login window is
popped up)....

					der Mouse

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