How to wake from sleep programmatically if lid closed?
Solution 1:
You can schedule wake up events with IOPMSchedulePowerEvent through the power manager. You may be able to schedule an immediate wake up. pmset is a command line wrapper for the power manager. You can also prevent sleep with IOCancelPowerChange in certain cases.
You may be able to prevent sleep or wake up by generating a mouse or key event. One way to generate events is with CGPostKeyboardEvent.
Edit:
Normal sleep is different from clamshell closed sleep. To affect the latter you must write a kernel extension like Insomnia.