[Rd] Ctrl-C with R.exe and Rterm.exe in R v1.9.0

[Prof Brian Ripley]

On Thu, 6 May 2004, Henrik Bengtsson wrote:

> > -----Original Message-----
> > From: r-devel-bounces at stat.math.ethz.ch 
> > [mailto:r-devel-bounces at stat.math.ethz.ch] On Behalf Of Duncan
> Murdoch
> > Sent: den 6 maj 2004 16:16
> > To: Henrik Bengtsson
> > Cc: r-devel at stat.math.ethz.ch
> > Subject: Re: [Rd] Ctrl-C with R.exe and Rterm.exe in R v1.9.0
> > 
> > 
> > On Wed, 5 May 2004 12:57:29 +0200, "Henrik Bengtsson" 
> > <hb at maths.lth.se> wrote :
> > 
> > 
> > >Ctrl-C works as expected. Exiting R and you're back at a "clean" 
> > >prompt. Now, try the same thing with R.exe (from a restarted
> prompt):
> > >
> > >C:\Program Files\R>rw1090\bin\R.exe --vanilla --quiet
> > >> ^C
> > >> ^C
> > >> 1+1
> > >[1] 2
> > >> Sys.sleep(100)
> > >^C
> > >C:\Program Files\R>
> > >>
> > >
> > >Strange things happen. R seems still to be running but has 
> > at the same 
> > >time returned(?) the control back to the Command prompt.
> > 
> > Yes, that is indeed strange behaviour.  
> > 
> > Ctrl-C definitely presents problems.  For instance, on my 
> > WinXP system running R from a Cygwin prompt, a Ctrl-C during 
> > the Sys.sleep kills Rterm, whereas under the Windows cmd.exe 
> > prompt it works properly as it did for you.
> 
> Cygwin is indeed where I noticed the problem first. For Cygwin, I know
> that Ctrl-C did not kill Rterm on R v1.7.1 and before, but from R
> v1.8.1 (don't know about R v1.8.0) it all of a sudden started to do
> it. Maybe there is a clue somewhere in the diff's between v1.7.1 and
> v1.8.x, which may also explain what is going on in R.exe and
> Rterm.exe.

No, as it was to do with a change in the MinGW runtime system and not in 
R.

Expecting to be able to use ^C as a Windows signal in a shell that is 
emulating Unix is I think unrealistic.  ^C in Rterm does work in tcsh.exe, 
cmd.exe and various clones.

It is becoming a mantra, but

  *** Cygwin is not Windows ***

and R is a Windows and not Cygwin executable.  People who want a Cygwin 
port of R perhaps should work on one ....

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595