Overwrite free space and inodes of a disk with 6 writes (fast but less secure) and show status

Securely overwrite the free space and inodes of the partition where the specified directory resides.
More information: <https://manned.org/sfill>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

sfill -l -v {{/path/to/mounted_disk_directory}}

click the source code to copy install sfill on any operating system with command-not-found.com