In a continuation of my desire to write really lightweight software that doesn’t add to the undesirable background bloat running on computers, I set about in June-ish to write something to improve upon a VBScript-Scheduled-Task-and-shutdown.exe gaffer tape of a solution to forcing a full shutdown when a computer is idle that I had previously cobbled together.

Power management in Windows is mature and capable, for sure, but what is less obvious is how to, on shared fixed desktop computers, actually trigger a proper shutdown and not just put idle machines to sleep. Hibernation is an option, of course, but the relentless increase in complexity of Windows brings to mind the other, stability-related, benefits of regular proper restarts.

So, then, we want something that:

• identifies when no-one is interactively signed in
• waits a configurable amount of time
• if still no-one has signed in in that time, shut down properly

Additionally, because this unavoidably must run with high permissions and regularly assess signed in users in the background, it should be a Windows service that is as lightweight and simple as possible. Reduced resource usage (RAM, CPU time in background) so we can shut down and have reduced resource usage (of electrical power). I can see the beauty of it already!

So I wrote ShutdownBuddy.

It is configurable through the registry:

HKLM\SOFTWARE\upfold.org.uk\ShutdownBuddy

EvaluationIntervalSeconds — DWORD. How frequently, in seconds, to evaluate for interactive sessions.

ShutdownAfterIdleForSeconds — DWORD. How many seconds of idle computer (i.e. no interactive sessions) before issuing a shutdown. This is periodically evaluated as above.

Like all my lightweight, C(++) Win32 projects, it is officially experimental as I am using these projects to learn how to write this kind of code properly. Any suggestions and improvements are gratefully received.