ACPI questions about press power button

David DEMELIER demelier.david at
Tue Sep 7 05:07:34 UTC 2010

2010/9/5 dave jones <s.dave.jones at>:
> Hello,
> I'm running FreeBSD 8 on my desktop. I want to write a file or do something
> when I or someone presses power button. In devd.conf, I added the
> following lines
> for testing:
>  notify 10 {
>            match "system"          "ACPI";
>            match "subsystem"      "Button";
>            matcho "notify"            "0x00"
>            action "echo hello world";
>    };
> But it doesn't work. Would anyone tell me how to do? Thanks.
> Regards,
> Dave.
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I think, you must first disable this setting because S5 is the default
behavior when pressing the power button, it calls /etc/rc.shutdown.

hw.acpi.power_button_state: S5

Disable it with sysctl hw.acpi.power_button_state=NONE and add this
line to /etc/sysctl.conf. And then maybe the power button will be
released for an other purpose?

Kind regards.

Demelier David

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