Is there a way to reuse a script when the UPS shuts down my Mac

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Level 1

5 points

Is there a way to reuse a script when the UPS shuts down my Mac

I have a Mac Studio running macOS Tahoe. I have a NAS connected and would like to send a command to the NAS to shut down when the UPS shuts down the Mac Studio. I don't see any way to configure the UPS to run a script when it shuts down. I don't want to shut down the NAS every time I shut down or restart the computer I only want it to shut down the NAS on a power failure when the UPS Battery level drops below a certain level.

Is this something that I can do with or without a third party package. The UPS is an APC and there is no software from the vendor that works with a MAC.

Thanks

Dan

Mac Studio (2022)

Posted on Oct 11, 2025 1:37 PM

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Answer 1

John Galt

Level 10

154,102 points

Oct 11, 2025 6:59 PM in response to DanDalio

I don't have a complete answer for you but I might be able to point you in the right direction. The solution would be to add a property list to /Library/LaunchDaemons/ that executes that command to the NAS upon system shutdown. You will have to determine or write that command; it's probably a shell script but all I can do is guess.

This assumes Energy Saver has been properly configured to shut down the Mac at a specified time and / or UPS battery charge state and that it actually initiates a system shutdown in the same manner as you would manually.

For an example read https://github.com/freedev/macosx-script-boot-shutdown/tree/master

Caveats:

it's old, and
I have no way to verify it will work.

However, it seems reasonable and should work.

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