I'm looking for tools that provide similarity checking of submitted program code.
Apart from the basic requirement of the tool being able to check for code similarity between submitted solutions there is one additional requirement that I am looking for: the tool should also check for code similarity between submitted code and code on internet (like on open websites such as SO or others).
I looked around and found that MOSS from Stanford is the most popular and widely used tool for code checking, but I couldn't find whether it checks for code on internet or not (all the examples of implementations only mention code similarity between two or more submitted solutions).
If there is any other tool that does this?