Shutdown your Mac Without the Warning Dialog
If you want to quickly shut off your Mac without seeing the warning dialog and without any sort of confirmation from the familiar power dialog box or otherwise, you can do that with a little known key modifier trick. Be aware that this approach is fairly abrupt, so you’ll want to use this sparingly for most purposes.
To shut down a Mac without seeing the warning dialog box, try holding down the ‘Option’ key while selecting “Shut Down” from the Apple Menu.
Holding the Option key while choosing to turn off the Mac will cause the system to shutdown without the two minute dialog box coming up to verify your shutdown or restart plans.
Do be careful with trying this one out casually, because there’s no warning, and the power controls box does not appear at all. Instead, all of your open apps will immediately begin to quit as the OS X shut down process begins and completes itself without any further user intervention (some apps with certain background processes may intervene unintentionally, such as Terminal with an active system specific task, but don’t rely on that since it certainly doesn’t apply to most users).
This is the power confirmation dialog box that gets skipped during this shut down process:
Even if the Auto-Save and Window & System Restore features of Mac OS X will save you sometimes from losing data, some apps don’t support those features, and with an abrupt system shut down, the Mac may not have enough time to generate adequate cache for the active applications to be able to gracefully restore. So again, use this sparingly, since most users like to keep their data.