Using Post-Build feature in Eclipse is a great way to augment a build with all kind of actions. What if the build takes a long time and you want to get notified? One way is to play a sound at the end of the build process.

Using Post-Build feature in Eclipse is a great way to augment a build with all kind of actions. What if the build takes a long time and you want to get notified? One way is to play a sound at the end of the build process.
The Eclipse CDT build system automatically scans the files in my project folders and adds them to the list of files to be built. That works great if files are added through Eclipse and its plugins: That way Eclipse is notified and aware, and has the files added. But what if I have added files externally (outside of Eclipse)? how can I make Eclipse aware of it?