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How to detect pending system shutdown on Linux?

Asked 2010-05-14T07:00:49.253
28

I am working on an application where I need to detect a system shutdown. However, I have not found any reliable way get a notification on this event.

I know that on shutdown, my app will receive a SIGTERM signal followed by a SIGKILL. I want to know if there is any way to query if a SIGTERM is part of a shutdown sequence?

Does any one know if there is a way to query that programmatically (C API)?

As far as I know, the system does not provide any other method to query for an impending shutdown. If it does, that would solve my problem as well. I have been trying out runlevels as well, but change in runlevels seem to be instantaneous and without any prior warnings.

c linux sigterm system-shutdown
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There is no way to determine if a SIGTERM is a part of a shutdown sequence. To detect a shutdown sequence you can either use use rc.d scripts like ereOn and Eric Sepanson suggested or use mechanisms like DBus.

However, from a design point of view it makes no sense to ignore SIGTERM even if it is not part of a shutdown. SIGTERM's primary purpose is to politely ask apps to exit cleanly and it is not likely that someone with enough privileges will issue a SIGTERM if he/she does not want the app to exit.

answered 2010-05-20T05:14:43.117

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