Hello, Alan.

On Fri, Feb 13, 2015 at 08:20:13PM +0200, Alan McKinnon wrote:
> On 13/02/2015 16:31, Alan Mackenzie wrote:
> > Hi, Gentoo.

> > I'm clearing out dross from my home directory, as me (not as root) and
> > I've just deleted this file:

> >     -rw-r--r--  1 root    root           0 Apr 11  2011 grep

> > , simply by typing $ rm grep.  I was prompted with:

> >     rm: remove write-protected regular empty file ■grep■?

> > , to which I responded 'y'.  The file is now gone.

> > So, as a non root user, I've managed to delete a file belonging to root,
> > to which I have no write access.  This is crazy!  I'm not happy about
> > this.  What's going on?



> Nothing is going on, the system is working as designed and is doing it
> correctly. It's not the permissions of a file that apply to deletion,
> it's the permissions of the directory it's in. Because that's all a
> delete is - remove one linee from the directory index and the file goes
> away.

Ah.  OK.  That seems fairly straighforward to grasp.

> It's also the exact opposite of creating the file, how does that work?
> Well you can't have write permissions yet on a file that has not been
> created, the permissions must be the directory. Same with delete.

> Trust me, there is no arguing with this - Unix has always worked this
> way and likely always will.

:-)  I ask myself, how come I've got this far without learning this
pretty basic fact?

Thanks for the explanation.

> -- 
> Alan McKinnon
> alan.mckin...@gmail.com

-- 
Alan Mackenzie (Nuremberg, Germany).

Reply via email to