[Rd] Unix-like touch to update modification timestamp of file?

[Gabor Grothendieck]

On Wed, Feb 27, 2008 at 1:27 PM, Henrik Bengtsson <hb at stat.berkeley.edu> wrote:
> On Wed, Feb 27, 2008 at 8:24 AM, Gabor Grothendieck
> <ggrothendieck at gmail.com> wrote:
> > If you only need Windows then this will do it even without RTools:
> >
> >  shell("copy /b /v myfile +,,>nul")
>
> Interesting.  Show I figured out that '+' is for "append", but how to
> interpret the two commas?
>

Commas generally have various undocumented effects in Windows batch
and sometimes Microsoft mentions one:
http://support.microsoft.com/kb/69581