Re: [APPL:DarwinDev] Re: cp -f option
Re: [APPL:DarwinDev] Re: cp -f option
- Subject: Re: [APPL:DarwinDev] Re: cp -f option
- From: "Jay A. Kreibich" <email@hidden>
- Date: Wed, 11 Oct 2006 15:29:18 -0500
On Wed, Oct 11, 2006 at 01:12:37PM -0700, Jeffrey Ellis scratched on the wall:
>
> on 10/11/06 6:32 AM, email@hidden at
> email@hidden wrote:
>
> >> Sorry for being dense. Not sure I understand exactly what this does. Can
> >> someone explain this...?
> >>
> >> -f For each existing destination pathname, remove it and create a new
> >> file, without prompting for confirmation regardless of its
> >> permissions.
> >>
> >> Doesn't cp do this by default unless you use -i or -n ...which this
> >> overrides?
> >
> > No.
> >
> > $ cd /tmp
> > $ cp /dev/null t
> > $ chmod 600 t
> > $ cp /dev/null t
> > $ chmod 0 t
> > $ cp /dev/null t
> > cp: t: Permission denied
> > $ cp -f /dev/null t
> > $
> >
> > -s
>
> Hi, Peter--
>
> Sorry, but could you please explain this output step by step? I'm not sure I
> really get what's happening...
The whole point of "-f" is expressed in the last four words of the
description: "....regardless of its permissions." "Its", in this
case, is the file that is about to be overwritten.
That's the difference between the default "no option" behavior of cp
and "-f". cp, by default, will not overwrite a file if the user
lacks write permission. "-f" will overwrite such a file, assuming
the user has permission to grant themselves write permission.
-j
--
Jay A. Kreibich | CommTech, Emrg Net Tech Svcs
email@hidden | Campus IT & Edu Svcs
<http://www.uiuc.edu/~jak> | University of Illinois at U/C
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Darwin-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden