Hi, I'm doing some custom Linux development for a consumer device. I've decided to use Slackware because A: its fast, B: its stable.

There is a catch to all of this though.

Background info:

Once the linux box boots up it will only run one program.
The program is a java based program which does some analysis and communicates through a serial port using the RXTX drivers. The only input device which will be connected to this box is a mouse. There will be no keyboard.

Question 1)

How do I autologin as a specified user in X? For example, I need the system to automatically boot into KDE and start this one application, lets call it APPX, when the system is turned on. I've got the inital boot level set at 4 right now. Thats fine when i have a keyboard, but not when i only have a mouse to login to the system with.

Question 2)

I've been trying to access the serial port using the RXTX driver for sometime now. I can do it when I'm logged in as root with no problems. I can't do it logged in as a normal user. Whenver i try, i get this error which states that my current use must be a member of group "uucp". I've tried editig the /etc/group file but that didn't seem to do it. I've even tried adding my current user to the root group and that didn't work. (It also didn't give me root privilages). How do I alter my user settings to allow me to be a member of group "uucp"?

Thanks!

Have a look at
</your prefix>/kde/share/config/kdm/kdmrc
You can set autologins there ...
May I suggest NOT to fire up kde if you just need one application?
Rather give that user a personalised .xsession file that starts that
one application...

What does the uucp entry in /etc/group look like, and what's
the related users numeric ID?


Cheers,
Tink

For autologin read carefully the docs for kdm, try the control center from kde and see session options for autologin.

For your other question, look at /etc/group if group uucp exist if not do as root
/usr/sbin/groupadd -g 14 uucp
and add your user to the group by edit /etc/group and type his name in the uucp line.

[edit]

Sorry for redundant answer I didn't see that Tinkster already did a reply

how would i go about starting a personalized x session?

here is the entry in the /etc/group file:

uucp::14:uucp,user

user is the user i want to add (named, you guessed it, user)

Well now, that looks correct. Membership changes like
that however only get picked up on a new login. Does
it still not work after having logged out and back in?



Cheers,
Tink

yes, i've restarted the computer twice and it doesnt work. Could it be that the JVM has its own user/group?

I've got it working now. Though i do have one question. How do create a custom .xsession that only boots one program?

Heres a thought for you on doing it
here i have kmail and my program of choice

1) as root navigate to

/etc/X11/xinit

2) Create a text file and name it xinitrc.kmail

3) past this in as follows to have something to play around with

this is taken straight from the xinitrc.twm minus all the xterms it starts. At the bottom you'll notice it starts twm. Just a window manager that uses a hell of a lot less resources than kde. As someone said above if all you want to start is one program to initialize kde unless its a must for some bizarre reason.

Next you'll notice it starts kmail with the geometry set as 1024x768+0+0. The first two numbers are obviously the the size of the box and should be set to whatever the screen resolution is. The +0+0 are the x and y coordinates of the top left corner of the program. Thus if the x and y are set to 0 and 0 and the size of the box is set to the screen resolution, the program will start taking up the entire screen.

The exec xterm... is necessary for twm to start, work, and get kmail going. Plus it will provide you with a terminal to 'su' with and fix things if you need to and then you can exit 'su' and issue the kmail -geo... or have a script to do it and have the program back up.

Now save the file

4) from /etc/X11/xinit

rm xinitrc
ln -s xinitrc.kmail xinitrc

Remove the current link which is whatever you chose as your default X session such as kde, gnome, etc and create a new link to what you just created.

5) issue startx et voila

Now im not exactly in a position to try this out at the moment but see if you follow me.

in /etc/X11/xinit
rename xinitrc.kde to xinitrc.other
then rename your xinitrc.kmail to xinitrc.kde
and then link xinitrc to xinitrc.kde

google and find out the command line to start the kde control panel and then go in and setup the autologin stuff and it should try and start the xinitrc.kde maybe

Of course now im just plain hacking around ( like i wasn't before )
This would enable you to boot the computer up straight to your program and if you need to, close your program and get to the xterm, launch kde control panel and make changes to what user is booting up.

The only thing left from that would be securing things up to keep people from messing around with it.

Just some thoughts

thanks alot, your answer really helped!