Passing arguments to display function

Good evening,
I’m quite new to openGL :o I’m using glut library. I hope it’s not very stupid question, but

how can I pass arguments to display function (except id)? I have the same problem with glui library, where I’m not able to pass arguments needed for my calculations to callback functions.
For example I need to pass a string to callback function of a button, that should appear when the button is pressed.

I don’t like using global variables :sick:

You can’t with glut. Use global variables