We have a large code base that has grown over many years with many different developers. By accident, we found a code snippet that has obviously been taken from an open source project, but without the corresponding license and reference to the origin.
What options are there, to find snippets like these?
I don't want to upload all of our code base to some service on the web and don't want to check manually.
Uploading smaller snippets to some search engine would be acceptable. What search engines are there?
What are best practices?