Oh thank god! This fixed it perfectly. Thank you SO much! I was bashing my head against this. I had been pouring through the documentation on POE::Filter::Line figuring it must be something to do with the terminating character on the output from udevadm. Never occurred to me to look right up at Wheel::Run. I stared at this trying various things for hours last night. I figured it had to be something to do with the particular output of udevadm. I'm glad I wasn't insane. I shall be naming my firstborn after you now.