Circadian is a background daemon/service for triggering suspend/sleep/hibernate automatically when a computer is idle.
Circadian uses a suite of 'idle heuristics' to determine when a system is idle. These include: * User activity in X11 (keyboard, mouse, full-screen playback) * User activity in terminals (typing in PTY/SSH session) * Open SSH connections * Open SMB/Samba connections * Active audio playback * CPU usage below specified threshold * Blacklisted processes
When all of its heuristics determine that your system has been idle for long enough, Circadian will execute a command. This is typically a simple power suspend, but it can be configured to any desired action.
Circadian exists because modern Linux distros already support suspend-on-idle, but it is apparently a very buggy and unreliable domain. After you've followed your distro's advice of poking a handful of conf files, tweaking a few XML hierarchies, writing a few scripts, wafting the smoke of burning sage across your keyboard, suspending gem stones from your machine, and whatever else may be recommended... perhaps try Circadian.
Completely unfinished. Perhaps don't try it now.