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I'd like my Mac laptops to shut down completely when I close the lid. This is partly for convenience and partly for security reasons.

I couldn't find a way to do this in the System Preferences (OS 10.8.1). Is there a way to control it by changing hidden preferences in the terminal, or some other method?

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Is it not enough to have it sleep and lock on sleep? – segiddins Sep 14 '12 at 22:26
If you want to save energy, you could also change the hibernatemode to 25. – user495470 Sep 14 '12 at 22:31
@SamuelE.Giddins No. "Hot" machines are more vulnerable to break-in attempts than cold ones that have been properly shut down. See this page for more info, particularly the section on power management. – Nick Sep 15 '12 at 10:23
How much security do you really need? I would only be concerned about an attack like that if you work with the Army or something. Paranoia is not healthy. – segiddins Sep 15 '12 at 15:57
@SamuelE.Giddins It's something that came up as part of a security audit for a client who handles medical records. I was hoping this was a good place to get help. Agree that paranoia can be unhealthy, but some data is worth being paranoid about. – Nick Sep 15 '12 at 16:02
up vote 2 down vote accepted

Though it's less and less true thanks to auto save, a shutdown in general may require user action (e.g., from an application that doesn't use the auto save model, or from an application that is frozen or becomes frozen when the OS tries to quit it). Therefore, any solution would not always work, because if the shutdown requires user interaction to complete, it will not finish (unless you want to do a forced-shutdown, which is a bad idea).

Also I should point out that this will do the exact opposite of saving energy, since booting the computer takes up a bit of CPU. The boot time will also make this the exact opposite of convenient. And due to what I said above, it won't be secure.

If you care about security, just enable a password when the computer is put to sleep. You can set the computer to shut down automatically at a set time every day in the energy saver preferences, and logout automatically after a given time of inactivity in the security presences (but the screensaver/sleep password is more secure, since logging out won't always work without user interaction either).

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I'm less concerned about saving energy and more concerned about saving time and the security of my company's machines. Sleeping a machine does not secure it as well as you might think. See this page for more. – Nick Sep 15 '12 at 10:27
@Nick, fair enough, but my other comment still applies. You would have to force a shutdown for this to truly be effective, which is very non ideal. – asmeurer Sep 15 '12 at 17:24

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