How to create a screen lock timer for Awesome WM?

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http://unix.stackexchange.com – I've got an Ubuntu 12.04 system with Awesome WM, and I'd like the screensaver to work like in Unity: GNOME Screensaver Ctrl-Alt-L to lock N minutes' timeout which respects applications which temporarily disable the screensaver The keyboard shortcut was relatively easy: -- Lock screen awful.key( { "Mod1", "Control" }, "l", function () awful.util.spawn("gnome-screensaver-command --lock") end) How do I solve point 3? (HowTos)