"finds and performs actions upon duplicate files" - man jdupes

jdupes is based on fdupes and is not written in java as the name may lead you to assume.


Recursively find all duplicates in a dir

jdupes -r /path/to/dir
jdupes -r -L /path/

Delete all but one duplicate

Although the flags do not indicate this, the following command keeps the first file (see man page for details), and prints a summary of what was kept and what was deleted.

jdupes -r --delete --noprompt /path/