How to Check if Macbook Lid is closed via Terminal? [closed]

Question

I'm running OS X 10.8 (Mountain Lion). I was wondering if there was a terminal command to check if the macbook pro's lid is currently closed. If I used grep, what would I be looking for exactly, and where?

The reason I ask is because I have cron jobs scheduled to run every 30 minutes. However, crontab doesn't run when the computer is sleeping/hibernating. My solution was to use pmset to schedule wakes every 30 minutes. However, I need a way to put my computer back to sleep on the condition that the lid is currently closed. I don't want my computer to be awake for too long with the lid closed i.e. awake all night when I'm sleeping because that could damage the screen.

Answer 1

ioreg -r -k AppleClamshellState -d 4 | grep AppleClamshellState  | head -1

Tested and works on 10.7.*, found here.

Update 2019-02-26:

Still works on macOS 10.14.3 Mojave