I wrote a similar (but simpler) script which would replace a file by a hardlink if it has the same content.

My main motivation was for the packages of Python virtual envs, where I often have similar packages installed, and even if versions are different, many files would still match. Some of the packages are quite huge, e.g. Numpy, PyTorch, TensorFlow, etc. I got quite some disk space savings from this.

https://github.com/albertz/system-tools/blob/master/bin/merg...