mac - Preventing closed Macbook from sleeping at startup

I have an old Macbook that I'm going to be tucking in a cabinet for use as a media server. It's currently running InsomniaX to keep it from sleeping when the lid is shut.

This works great when I start the Macbook with the lid open, wait for it to boot to the desktop (automatic login is enabled), then shut the lid. It stays running. This is good.

The problem is that when I start the laptop with the lid already closed, it boots to the desktop, but the lid detection puts the machine to sleep before InsomniaX has a chance to load. (Even though it's one of the Login Items for the account.)

Is there any way, be it hackish, technical, etc. to prevent the laptop from sleeping immediately? Even if it were to spin at the desktop for 30 seconds, it would give InsomniaX time to load.

Answer

Create a login hook that calls a script. Let's call this script noidle and put it somewhere, maybe ~/noidle.sh.

#!/bin/sh
pmset -a disablesleep 1

This script should run once and prevent sleep. To add this as a login hook, run:

chmod +x /Users/your-username/noidle.sh
sudo defaults write com.apple.loginwindow LoginHook /Users/your-username/noidle.sh