rm -P switch?

[michaelsanford]

I was curious about the wording of this in the rm manpage:

     -P    Overwrite regular files before deleting them.  Files are overwrit-
           ten three times, first with the byte pattern 0xff, then 0x00, and
           then 0xff again, before they are deleted.

Presumably this is to add security so that undelete apps can't read the byte pattern from the hard disk but: It's overwritten 3 times before it's deleted?

 

[DeltaMac]

A file can't be overwritten AFTER it's deleted, can it?

 

[michaelsanford]

I suppose you're right, I was just thinking that the file would be deleted, and the physical location of the file would be stored by rm and then overwritten; but I suppose that's crazy since rm probably doesn't have anything to do with the physical location of the file...

 

[ex2bot]

Mike,

Your message fits better in the Mac OSX Unix & X11 forum, so I moved it there.

Have fun.

Doug

 

[michaelsanford]

I just noticed that forum was unix (I only noticed the X11 in the title, not the "unix", and wondered where the Darwin forum went).

Sorry

 

[scruffy]

Yes, that's so as to erase a file thoroughly, i.e. unretrievably. This is similar to PGP's 'wipe' command.

Thanks for pointing out that option though