If you could post a tiny snippet using Lirc::Client, showing how you get output, it would make it easier. Your problem is in finding a way to keep the Lirc read-loop going, without blocking the Tk GUI. It basically should be pretty easy, but you have 2 paths to take. One is let the Tk event-loop monitor the Lirc ( at fast time intervals ) and put the results into a text box. The other option, is to start the Tk gui, then let the Lirc read-loop run after the gui is up and running, and in your Lirc-read-loop print the output with $text->insert('end', $output\n"); When you do it that way, you will have to call $mw->update everytime thru the loop.

But if you could show a small code snippet, we could show you the best ways.