fdupes

fdupes is a command line tool that is used to find and delete duplicate files within a specified directory or set of directories. It works by comparing file sizes and then performing a byte-by-byte check to determine if the files are identical.

fdupes provides various options to customize the search criteria, such as matching based on file name, file size, or both. It can also recursively search through subdirectories and prioritize which files to keep or delete.

One of the key features of fdupes is its ability to support hard links. Instead of simply deleting duplicate files, it can replace them with hard links, which saves disk space by allowing multiple files to reference the same physical data. This ensures that even if a file is deleted, the hard link will point to the original data and prevent data loss.

Overall, fdupes is a powerful and efficient tool for managing disk space by identifying and removing or replacing duplicate files. It is available for Unix-like operating systems, including Linux and macOS.