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Dear all,

I wrote a program in C language which has to
display a message box on the screen (in X windows).

I used the following code
Code:

system("kdialog --mesgbox \" Some Message text\"");

I works well When I run it in the background manually on the console
but It doesn't work When I put it in /etc/rc.local file.

/etc/rc.local contains the following line:

Code:

/usr/local/bin/myprogram &

The above program gets executed but the dialog doesn't appear.


Please give me some idea...

Thanks

Whats the error output say? It could be that kdialog is unable to run due to lack of a running X server, or is unable to find the server, or possibly other conditions of its starting.

SciYro is correct. When rc.local runs at boot time, there is no locally running X server upon which to display the output. You could set up a remote X server that will accept connections over the net, and then set $DISPLAY in rc.local to point to the X server. Or, if you don't actually need to see the output dialog, you could run a virtual X server like Xvfb, which will allow the application to run, albeit invisibly. Dialog boxes usually require user interaction in order to carry on, which usually makes them unsuitable for use in the boot process.
--- rod.

Dear members,

Thanks for your valuable replies..

The program is started while booting but will run continuously for
every five minutes in the background.

The particular code snippet will be executed while the
user is working with some applications on the desktop...


thanks

I have managed a similar situation, where I want a perpetually running application that also has an interactive console to be launched at boot time, on a headless machine. I accomplished this by running Xvfb, which can then host an xterm that hosts a Gnu screen session, running in multi-user mode. In rc.local, I use screen's 'stuff' command to start my application, which then runs. All of this is done in rc.local.
Later, from anywhere, I can attach to the screen session to monitor and interact with the application. Multiple users can do this, concurrently. Its a monumental hack, but it works.
--- rod.