First, on an R console, stdout() is normally neither a `normal file' nor a
`user terminal'. Let alone under an embedded R ... or use under ESS
(where for you, Martin, it is neither).
On vanilla R under Unix-alikes (and Rterm but not otherwise) what stdout
is is a function of the C runtime system. It's up to the C system if it
tells you what stdout has been redirected to, and if it can tell you
whether it is a terminal, or a pty (as used under some versions of Emacs)
or a file or a socket .... The information is at best unreliable.
interactive() is as good a test as we have, and I think if a better test
is required in the interactive case, the user should be asked.
On Wed, 12 May 2004, Martin Maechler wrote:
> >>>>> "MartinS" == Martin Schlather <[EMAIL PROTECTED]>
> >>>>> on Wed, 12 May 2004 09:15:17 +0100 writes:
>
> MartinS> Dear Ben,
>
> MartinS> I do not know how to solve the general problem that
> MartinS> backspaces cause within Sweave, but which are
> MartinS> needed to implement running counters.
>
> aha! now I understand more what you are talking about.
>
> This is a more interesting problem, in general: It's not quite a
> matter of if(interactive()) that Ben tried, but really you want
> to find out if the stdout() connection you are using is a normal file
> (where you don't need or want a running counter) or a
> user terminal where Martin Schlather applied the 1^H2^H... ('1' Backspace
> '2' Backspace ..) trick.
>
> Any ideas what can be done here, using our current connection
> tools -- or is there the need for something new?
> Interesting topic!
>
> Martin Mächler
>
> PS. I know that strictly speaking the subject question is
> non-sense, since, at least on Unix-alikes, a console is a
> special file as well, and stdout is always a file.
--
Brian D. Ripley, [EMAIL PROTECTED]
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
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