[taxcontrol]

Look into the Linux command - dd

https://www.marksanborn.net/security/securely-wipe-a-file-with-dd/

[zeugma]

Look into the Linux command - dd

LOL. You have to be very careful when using the dd command. It is extraordinarily powerful and you can easily wipe out stuff that you don't intend. The difference between 'dd if=/dev/zero of=/dev/sde1' and 'dd if=/dev/zero of=/dev/sdd1' can be kinda catastrophic.