rm -rf file/folder
This is the easy way and quick way. But if you want to delete something that is hard to recover, then you need other tools.
shred, used to securely delete files and devices so that they can be recovered only with great difficulty with specialised hardware.
shred -f file
There is no option to delete folder ‘r’.
secure-delete, srm is a secure file removal utility.
sudo aptitude install secure-delete
srm -r pathname
Shred’s default is twenty five but secure-delete uses thirty eight.