rrm
This program takes filenames as arguments. It overwrites the contents of these files with zeros, replaces the filename with a random one and then unlinks the files.
It requires a C development environment and the make program.
The source code is available from the github repo.
Warning
It will not work on e.g. log-structured file systems or copy-on-write file systems. On such file systems there is no guarantee that writing to the beginning of a file actually overwrites the same physical area that the content originally was in. This probably includes SSD and flash drives.
For comments, please send me an e-mail.