Is it possible to compile ffprobe in linux as a library (ffprobe.so)? Couldn't find nothing on google about it. If yes, any references on how the library can be used?
ffprobe is a command-line tool, not a library; it's a relatively thin wrapper around libavformat/libavcodec. If you want a library, use those directly.
Here's the full source code to ffprobe. It's a bit long, as it can print a lot of information about some file formats, but it shouldn't be too hard for you to pick out the bits that you care about.