From jorismeys at gmail.com  Fri Apr  8 17:14:08 2011
From: jorismeys at gmail.com (Joris Meys)
Date: Fri, 8 Apr 2011 17:14:08 +0200
Subject: [Rd] Invalid connection after closing?
In-Reply-To: <4D9F252A.3020702@gmail.com>
References: <BANLkTin3MO-f_dLz4RnCRnj_EXP-Bd=c3Q@mail.gmail.com>
	<4D9F252A.3020702@gmail.com>
Message-ID: <BANLkTikazPA34K0BjONF5tBv_0DAkbMMfQ@mail.gmail.com>

Thx for the information. I read it, but I wasn't sure what was going
on inside. Is there a way to close a connection without destroying it?
Guess not, but you never know...

Cheers
Joris

On Fri, Apr 8, 2011 at 5:09 PM, Duncan Murdoch <murdoch.duncan at gmail.com> wrote:
> On 08/04/2011 10:56 AM, Joris Meys wrote:
>>
>> Dear all,
>>
>> I do not completely understand following behaviour :
>>
>> > ?con<- file("test.txt")
>> > ?isOpen(con)
>> [1] FALSE
>> > ?open(con)
>> > ?isOpen(con)
>> [1] TRUE
>> > ?close(con)
>> > ?isOpen(con)
>> Error in isOpen(con) : invalid connection
>> > ?str(con)
>> Classes 'file', 'connection' ?atomic [1:1] 3
>> ? ..- attr(*, "conn_id")=<externalptr>
>>
>> Why do I get an error, indicating an invalid connection, after I
>> closed a connection? Is this to be expected?
>
> Quoting ?close: " ?close? closes and destroys a connection. " In the current
> implementation, connections are a finite resource, and you need to be able
> to get rid of them when you are done. close(con) is the way to do that. If
> you want to re-open it, you need to remember the filename (or extract it
> before calling close()), and issue another call to file().
>
> Duncan Murdoch
>



-- 
Joris Meys
Statistical consultant

Ghent University
Faculty of Bioscience Engineering
Department of Applied mathematics, biometrics and process control

tel : +32 9 264 59 87
Joris.Meys at Ugent.be
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[Rd] Invalid connection after closing?
Joris Meys