Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: sunloop!oconnor!porsche!miker@central.sun.com (Mike Raffety)
Newsgroups: comp.sys.sun
Subject: Re: How does screenblank(1) calculate idle time
Keywords: Software
Message-ID: <8903311618.AA13384@porsche>
Date: 22 Apr 89 08:08:23 GMT
Sender: usenet@rice.edu
Organization: Sun-Spots
Lines: 4
Approved: Sun-Spots@rice.edu
Original-Date: Fri, 31 Mar 89 10:18:47 CST
X-Sun-Spots-Digest: Volume 7, Issue 239, message 4 of 21

screenblank checks BOTH the access and modify time on the devices (usually
/dev/kbd and /dev/mouse).  When an event occurs on either, a read(2) is
done to get the data, and the access time (ls -lu) is updated.
screenblank simply watches to see when those times get "old".