Howto Turn your old webcam into a motion-detecting security camera in Linux

If you have an old cam that you are not using, you can use it as a security cam. Control Motion is a program that monitors the video signal from one or more cameras and is able to detect if a significant part of the picture has changed; in other words, it can detect motion. The program is written in C and is made for the Linux operating system (using the video4linux interface). Motion is a command line based tool whose output can be either jpeg, ppm fies or mpeg video sequences. Motion is strictly command line driven and can run as a daemon with a rather small footprint.