The samefile program helps you find identical files on your file systems.
Identical files don't have to have the same name to be found by samefile.
The input is a list of filenames, e.g. from ls(1) or find(1). The output
is a list of file name pairs along with some other useful information.
Samefile comes in handy when you
- are notoriously low on disk space. It will probably find megabytes of
redundant files that you can then hardlink, symlink or remove.
- want to know what files in two subdirectory trees have (not) changed.
The program is reasonably fast to even check any file against any other.