X11 Window System¶
Looking around on Ubuntu
/etc/X11 is a good place to start
Xsession is invoked by the display manager.
See ‘man 5 Xsession’
Xsession redirects stdout & stderr to $HOME/.xsession-errors almost first thing
Xsession.d/* has a bunch of scripts that are sourced in order by Xsession:
20x11-common_process-args: sets STARTUP if arg passed to Xsession
40x11-common_xsessionrc: will source $HOME/.xsessionrc if it is readable
50x11-common_determine-startup: will set STARTUP to ~/.xsession or ~/.Xsession but ONLY if the display manager has not already set a startup command by passing it to Xsession - or so the comments say…
Also look at /etc/kde4/kdm:
kdmrc: LOTS of useful config stuff - read the comments
Which directories kdm looks in for different desktop sessions - It might just use the first of these where it finds anything??????
/var/lib/menu-xdg/xsessions (no such dir)
/usr/share/kde4/apps/kdm/sessions (a zillion files, I suspect it doesn’t look here since others come first)