Hole thing is happening on the mac os x. Let's assume that I've opened an program by clicking on an .app icon. It's a python program with GUI which has a separate process that waits for a user input. But as I've opened it by clickin .app icon I dont have access to it's input as I would have if I opened it in Terminal. And the question is: How can I connect new Terminal window to this running program? I tried pipes but I'm not sure how to use them correctly. My guess was to find PID of the app that is running and then pipe to this program by giving a PID. But I have no idea how to do it. I hope you were able to understand what's the problem. Sorry for my weak english :)