R help - Sep 2010 - limit on read.socket?

Hi,

I have the following piece of code,

repeat{

ss<-read.socket(sockfd);
if(ss=="") break
output<-paste(output,ss)
}

but somehow, output is not receiving all the data that is coming through the
socket.My suspicion is on the if statement. what happens if a white space occurs
in between the string arriving over the socket?
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On Sat, 4 Sep 2010, rajeshj at cse.iitm.ac.in wrote:
>
> Hi,
>
> I have the following piece of code,
>
> repeat{
>
> ss<-read.socket(sockfd);
> if(ss=="") break
> output<-paste(output,ss)
> }
>
> but somehow, output is not receiving all the data that is coming through
the socket.My suspicion is on the if statement. what happens if a white space
occurs in between the string arriving over the socket?
That's not the problem.  The problem occurs when R reads faster than the
data are provided -- R will read and there will not be any new data available,
so ss will be the empty string and the program will end.

In general you can't rely on the sender transmitting data fast enough to
keep ahead of R.  The example in make.socket() is reading a very small amount of
data, so it worked reasonably well back in the days when the finger daemon was
more widely active.   You need some more precise way of knowing when the data
stream is over.  This could be some sort of 'end of transmission' marker
or a count of the number of bytes or lines to be expected.

    -thomas

Thomas Lumley
Professor of Biostatistics
University of Washington, Seattle