[R] console from tcltk

[Prof Brian Ripley]

On Wed, 14 May 2008, Gabor Grothendieck wrote:

> Thanks.  I've updated to the latest R on the mirror I used and
> puts stdout 12
> from tcl does indeed produce output from Rterm on Windows but gives an
> error message from Rgui on Windows (both on Windows Vista SP1).

Not if you launch Rgui from a terminal, as the quote I gave described.

>
> ----------------- this works
>
> C:\tmp2>Rterm
>
> R version 2.7.0 Patched (2008-05-11 r45672)
> [...deleted...]
>> library(tcltk)
> Loading Tcl/Tk interface ... done
>> .Tcl("puts stdout 12")
> 12
> <Tcl>
>> xx <- .Tcl("puts stdout 12")
> 12
>
> -------------- this gives an error message
>
> C:\tmp2>Rgui
>
> R version 2.7.0 Patched (2008-05-11 r45672)
> [...deleted...]
>> library(tcltk)
> Loading Tcl/Tk interface ... done
>> xx <- .Tcl("puts stdout 12")
> Error in structure(.External("dotTcl", ..., PACKAGE = "tcltk"), class
> = "tclObj") :
>  [tcl] can not find channel named "stdout".
>
>
> On Wed, May 14, 2008 at 11:09 AM, Prof Brian Ripley
> <ripley at stats.ox.ac.uk> wrote:
>> I assume by 'console' you mean the Rgui window.  That is not where stdout is
>> connected -- it is not a file.  As the CHANGES file for 2.7.0 says
>>
>>    o   When Rgui is launched from a terminal, C output from ill-formed
>>        packages that write to stdout or stderr rather than use
>>        Rprintf will appear in the terminal rather than being lost.
>>        (Only on XP or later.)  This can be very handy for debugging C
>>        code in packages: just write debugging messages to stdout.
>>
>> And indeed that is what your example does.  It also writes to the terminal
>> from Rterm.
>>
>> Tcl is no different from any other C-based add-on in this respect.
>>
>> Note though that system() does provide a way to capture stdout to the Rgui
>> window, so you can probably run tcl scripts via the tcl shell and capture
>> their output.
>>
>> On Tue, 13 May 2008, Gabor Grothendieck wrote:
>>
>>> Is it possible to use the console from within tcltk?
>>>
>>>> library(tcltk)
>>>> tcl("puts", "stdout", "Hello, World")
>>>
>>> Error in structure(.External("dotTclObjv", objv, PACKAGE = "tcltk"),
>>> class = "tclObj") :
>>>  [tcl] can not find channel named "stdout".
>>>>
>>>> .Tcl('puts stdout "Hello, World"')
>>>
>>> Error in structure(.External("dotTcl", ..., PACKAGE = "tcltk"), class
>>> = "tclObj") :
>>>  [tcl] can not find channel named "stdout".
>>>>
>>>> R.version.string  # Windows Vista
>>>
>>> [1] "R version 2.7.0 RC (2008-04-17 r45367)"
>>
>> Oh dear, not even the released version!  Please update as the posting guide
>> asked you to do before posting.
>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>> --
>> 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
>>
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
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