fdupes is a great little tool that can be used to find duplicate files inside one or more directories. It does this by checking the file sizes, MD5 hashes and a byte for byte comparison of the files.
- To install the tool:
$ sudo apt install fdupes
- To ask the tool to find and list duplicate files inside a directory
$ fdupes -r foobar/
Tried with: fdupes 1.6.1 and Ubuntu 18.04