I have Knoppix installed on my hard disc (distro 7.0.2, kernel release 3.3.7).

How do I use my own custom startup file that will run when X Window starts?

I've put an executable shell script in the directory /etc/X11/Xsession.d/ but
the command inside it doesn't run.

Please could you tell me what's wrong, and what I need to do? Thanks.

Full Desccription

When X Window starts, I'd like to use an X11 startup file to run the Kate
editor so that a Kate window appears, containing the file I want to view. I've
put a startup file in the directory /etc/X11/Xsession.d/ called "a90-custom"
(named so that it runs last). It's a bash script (made executable) containing

#! /bin/bash
kate --new /home/knoppix/text-file.txt &
But after bootup, and after X Window starts, the Desktop appears but with
no Kate window showing.