Re: New feature in mv

[Pádraig Brady]

On 12/05/2012 01:25 AM, Raphael S Carvalho wrote:
> On Tue, Dec 4, 2012 at 11:05 PM, Pádraig Brady <address@hidden> wrote:
> > On 12/05/2012 12:45 AM, Raphael S Carvalho wrote:
> > > On Tue, Dec 4, 2012 at 10:22 PM, Pádraig Brady <address@hidden> wrote:
> > > > On 12/04/2012 05:04 PM, Paweł Lampe wrote:
> > > > > Hi there !
> > > > >
> > > > > Few minutes ago, my mate asked me 'is there any way to swap two
> > > > > files ?'. I have realized, that the mv has option -S but it's all about
> > > > > suffix. I think, there should be also -s for swapping. It should work
> > > > > like:
> > > > > mv -s a b
> > > > > Effect should be like:
> > > > > a -> tmp
> > > > > b -> a
> > > > > tmp -> b
> > > > >
> > > > > Think about it
> > > >
> > > >
> > > >
> > > > A fairly useful feature, but something as noted here
> > > > that might be more suited to a separate script,
> > > > that could be maintained within coreutils under the
> > > > recently mentioned contrib/ directory
> > > >
> > > > http://lists.gnu.org/archive/html/bug-coreutils/2009-02/msg00014.html
> > > >
> > > > thanks,
> > > > Pádraig.
> > >
> > > I read this page:
> > > http://lists.gnu.org/archive/html/bug-coreutils/2009-02/msg00014.html
> > > So I would really like to create that program. Is it still even needed?
> >
> >
> > Cool, thanks!
> >
> > I would prototype a script in shell,
> > with possibly some of the same considerations as in this "rewrite" script,
> > http://lists.gnu.org/archive/html/bug-coreutils/2010-03/txtNTX6owUFov.txt
> >
> > thanks,
> > Pádraig.
>
> I was thinking about writing such a program using C language, though
> I'm not sure if it would be the best choice. I could search for the
> best data exchange algorithm, so making the program fast and useful.
> I'm not sure if they(maintainers) would accept a new program in the
> core-utils. As I'm seeing, the program would provide a way to exchange
> data between two files, besides changing filenames. Should another
> one(feature) be implemented?
> I also thought about using Python.

The idea here is that swapping files would be just a thin
wrapper around the mv or cp or ln utilities which
already do the heavy lifting in C for copying data
around (often using complicated techniques), or
in fact just renaming as appropriate.

thanks,
Pádraig.