When is a file actually deleted?

[dmedici]

First, I'd like to say 'thanks' to Jethro and sOnic and the others who were giving me a lot of good answers in the live chat on this topic.
I thought this might be interesting as it is all over the news relating to security, terrorism, and hacking/cracking.
That kid a few days ago from Austria (I believe), who hacked into the Pentagon. If I were him, and I wanted to clean the evidence from my hard drive, what would I do? Because the 'delete' button (at least as far as I understand in Windows) doesn't really delete a file, it just deletes the pointer, correct? What about other systems, i.e. RedHat, BSD, etc.?
I think a tutorial may be in order here. Anyone want to volunteer?
So to summarize...

When is a file actually deleted from your hard drive?

[jethro]

In about half an hour, expect a lovely program that will deal with this, for you. I'm just working out the finer points of it on IRC at the moment....

[valhallen]

your correct when you say that a file isn't deleted it just removes the pointer - this means that windows then sees that space as free again and writes over the top of it....this is when most people consider a file to be completely erased as it has been written over.
But I think I remember reading an article claiming that the NSA could recover files from HD's that had been written over up to 24 times!
So I would say a file is truely deleted when you

• Smash your HD with a sledgehammer
• turn the bits into dust with a chainsaw
• burn the dust
• throw the ash out to sea

maybe just maybe if you do all of that they won't be able to recover the files
hehe

v_Ln

[jethro]

Maybe something like this might work

/* File Massacre
   Email Jethro @
   jethrojones@gmx.net */

#include <fstream.h>
#include <io.h>

#define PROG_NAME "File Massacre by Jethro"

void main()

{

cout  << PROG_NAME << endl;

int i;

for (i=1; i<=1000; i++) {

      ofstream File;

      File.open("killme.txt");

      File.close();

      _unlink("killme.txt");

      }

}

[str34m3r]

Sorry jethro, but I don't follow... what is that code supposed to do?

[cwk9]

dmedici you can find programs that will write data over the file so they can't be recovered with any undelete programs. That should be good enough but if you’re truly paranoid you can write over the data as 30 times just to be sure. But now you might be thinking what if the FBI comes, breaks through the door and tries to steal my hotmail password, I wouldn’t have time to write over the data 30 times. Well in that case you use a removable hard drive and when the FBI comes you can just take it out and dump it in a vat of battery acid that you keep beside your desk.

[komal]

Yup its true, the file isn't deleted, it just get erased from your mind. Files are enver actually deleted, just written over, so the you won't have much luck with the delete keys. But there are a few solutions, for one thing, you can get a hard drive killer, get an extra comp, hack, do whatever, and run a hard drive killer, they are probably pretty effective. Option number 2 is getting one of those proggies that make sure the data you delete is unrecoverable.

[shkuey]

Maybe something like this might work

Overwriting the same file name over and over is not the same thing as writing over the sector of the hard drive that contains the file.

[komal]

Sorry about my spelling mistakes, I use quick reply, and don't check over any errors.
it just get erased = it just getg erased
Files are enver = Files are never

[komal]

Oops, another one
getg = gets
sorry about these annoying posts, but they do after all keep the thread on top.