serial read

Hello guys!
I have successfully written and tested a programm for arduino, which is sending two numbers to the computer over usb via serial. Everything works perfekt with the arduino pc suite, but i want it to start a programm when it casts a specific value. i don't know how and where to start please could anyone help me out. PS: i am using ubuntu 10.10 and i have thought, to make a c programm, but i don't get results.
Thank you and i hope i posted in the right section of the forum(soory i am new here).

Every one needs to start somewhere. Perhaps you could tell us more about what you want to start off with. Do you want the arduino to send something specific to the PC or is it the other way around? Have you looked at some of the tutorials out there that do something similar? Perhaps you need to start off with one of the beginner arduino books so you can do something similar to get you started?

thank you for the fast reply!
i have two arduino beginner books, but it has nothing to do with the arduino itself. The software and the hardware works perfectly. i have written a small programm that sends an ascii 1 if a button is pressed and a 2 if the 2nd button is pressed over the usb/serial port to the computer. I search a c code, that can handle inputs from the arduino, so i can start a shell script with it.

Correct me if I misunderstand. Now you want to look at the value returned from the arduino on the PC and do something based on which value you received, right?

yeah right, but this is what i ment from the beginning on

OK, at this point I have to let someone else help you. I haven't done a single thing with the USB port input to the PC from the arduino.

good luck.

Check out this post:

it has some sample code in VB.Net on performing serial communication.