Unfortunately, the steam client now reserves the space that is needed at the start of a download, so that the size of the /SteamApps/ folder does not change during the download, which limits the functionality of the SteamStalker. I will update it when I've found a new method.
SteamStalker is a program that automatically shuts down your computer after Steam has finished its downloads. This is very useful if you want to download a game/program on steam during the night.
Automatically shut down your PC after Steam has finished its downloads