These files are supplied as part of an Instructable that describes how to build a photobooth using a Raspberry Pi as the "brains" of a camera, printer, and user interface controller.
Addition Pentax version: Getting pslr-shoot from the PK-Remote project by just compile the command line tool:
sudo make cli
sudo make installPentax version uses button with long press (> 2seconds) for shutting down the Raspberry Pi.