The way you talk about skrub simply amazing, as if you are the first one who came up with the idea. You’re just reinventing the wheel, and doing it wrong:
- I don’t care whether the file content stays on disk or not, as long as I can utilize the free space.
- If I do care, then I probably want to make sure that no one can recover it, which is not simply possible with flooding the file with zero-filled (?) bytes. There are proper ways to do it.
A simple Google search would reveal better results.