Hi Devs,

I have a requirement in application. It needs to be notified when the system is about to sleep, so that I can prevent the system to sleep as my application is downloading some data. I want to enable sleep after the downloading is done. So, I need the following to be specific

1. AbouttoSleep signal
2. preventSleep(bool)

Thank you
Sanjoy

I've never need to do this, so I'm just guessing. If I'm right, you'll need to add a sleep action to /etc/acpi/events/ and a corresponding action script to /etc/acpi/actions.

Look at man acpid and man acpi_listen and the Wiki article on ACPI

Note: Some BIOS settings can put devices in sleep mode without communicating (much) with the OS, so you should check your BIOS settings. (A modern BIOS would, I think, first raise one of the S3 flags, but, as I said, my knowledge is all theoretical.)

P.S.: I only replied here because your query has languished for some time with no replies, and it seemed like an interesting question.