How do I programatically take a screenshot of an application in Linux?

How do I programatically take a screenshot of an application in Linux? I'm using c++. Any idea? For windows there are a lot of resources but I can't find anything for linux

Any help? Thanks

Solution

If you just want a screen recorder, try using xvidcap. If you want to make your own, try looking at the sources. I'm not really sure how it works though. My guess is that it uses the XShm extension somehow.