rencon is a simple, safe tool able to rename files based on their content. Example usage: rencon -m 'r_${hash}.${ext}' *.jpg It will rename all .jpg files with a hash based on their content, and add "r_" to distinguish them. The default mask is ${hash}.${ext}. The hash used is SHA1. For more information, run rencon -h. It does not erase existing files. While it can be used in that way it does not aim to do file deduplication.