On Fri, 1 Jun 2007, mel wrote:
Prof Brian Ripley a écrit :
I use getConnection().
In the context in which I use it, the number of the connection is
known a priori.
I don't see how you can know it 'a priori': it is an implementation detail
(and since R itself uses connections, those details could easily change).
(disclaimer : I don't claim its the best way to proceed)
Before launching my app, the connections context is :
> showConnections(all=TRUE)
description class mode text isopen can read can write
0 "stdin" "terminal" "r" "text" "opened" "yes" "no"
1 "stdout" "terminal" "w" "text" "opened" "no" "yes"
2 "stderr" "terminal" "w" "text" "opened" "no" "yes"
So, the call to socketConnections() creates always (at least
for all my experiments) a connection with number 3.
Btw, if (socketConnections(...) != 3) the application simply
don't launch.
So, if the application runs, it's sure that this is with a
connection number==3.
That's why I say that "the number of the connection is known a priori".
You don't *know* that: it depends on how R internally numbers connections
and what the startup code does. That detail will almost certainly change.
Of course, the connection number could also be retrieved eg using
the description field.
For now, at least.
--
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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