For those like me who are paranoid and want to remove information from their system in a way that is irrecoverable (or almost), here is a solution.
Let's install the package: secure-delete
Then it will be enough to use the command
srm and it will erase the directory or file that we want safely.
How does this work?
Simple. When we normally delete something from our system, in reality that information was not eliminated, but in the HDD it was «pointed out» that the sectors that occupy this data are 'empty', then when we copy something new to our HDD over time, little by Little is really being eliminated from the information that occupies those sectors previously indicated or marked.
Well, srm what it does is delete that information as we normally do, but not only this, but it writes and deletes several times in the same space that the deleted information occupied, that is, it deletes and writes, deletes and writes, in this way makes it almost impossibleunless they have specialized equipment like CIA, FBI, NSA, etc. haha) to be able to recover the deleted information.
For example, to delete a file it would be:
If I want to delete a folder with all its contents:
srm -r carpeta-personal/
This I clarify, it will take a long time, but much longer than normal. Remember that it is written and erased several times, obviously this will take up much more time than normal. But of course ... if something wants something it costs him, if we want to eliminate information as safely as possible, it will take us some time 😉
However, if you want it to take less time, you can use the parameter
-l What this does is that it will only be written and erased twice, it will speed up the erasure process but it will not be as secure as it is by default.
Anyway, I don't think there is much more to add.