Functionality isn't covered by copyright; it needs a patent. You could even have identical files, if it's the simplest way to do something: https://en.wikipedi

Functionality isn't covered by copyright; it needs a patent. You could even have identical files, if it's the simplest way to do something: https://en.wikipedia.org/wiki/Google_LLC_v._Oracle_America,_Inc https://en.wikipedia.org/wiki/Google_LLC_v._Oracle_America,_....