Caffeine is a small tool designed to prevent your PC from locking or going to sleep.
It prevents PC sleeping/locking by simulating that you've released the F15 key once every 59 seconds by default. You can easily enable/disable Caffeine as well as setting time periods for activity or inactivity. Double-clicking the systray icon empties the coffee pot (that's what the icon is) and temporarily disables the program.
Caffeine is a useful tool when the need to keep your PC awake or unlocked arises, and using it via the systray in the perfect manner for those that may be a little less experienced. Still, it can be utilized via the command line, which advanced users will appreciate.
Since Caffeine operates by default at 59-second intervals, you will be able to alter this behavior via command-line switches:
xx - where xx is a number that sets the number of seconds between simulated keypresses. This must be the first text on the command line
startoff - application starts disabled.
exitafter: xx - application will terminate after xx minutes
activefor: xx - application will become inactive after xx minutes
inactivefor: xx - application will become active after xx minutes
appexit - terminates current running instance of an application
appon - makes the currently running instance of the application active
appoff - makes the currently running instance of the application inactive
apptoggle - toggles the running state of the currently running instance of the application
apptoggleshowdlg - toggles the running state and shows the dialog
replace - closes the currently running instance, replacing it
noicon - does not show a task tray icon
useshift - simulate the shift key instead of F15
showdlg - shows a dialog indicating whether caffeine is active
ontaskbar - show a taskbar button (use with -showdlg)
allowss - prevent sleep, but allow the screensaver to start
keypress - simulate a full keypress, not just a key up event