See package svSocket in the SciViews bundle. It uses a socket server
written in tcltk and it is not blocking the command line.
Philippe Grosjean
pau carre wrote:
Hello, I tried to code a R socket server but I did not succeed.
The problem is that once the R socket server is created,
I call the readLines function and then R gets blocked.
The client seems to work fine since I tested it with a PERL server.
I tried many combination of params in the socketConnection but
none of them worked.
I have seen some examples where the server sends something to a
client but I need the opposite example.
Thanks,
Pau.
The R server
FSsocket() <- function(){
print("Creating server on localhost")
conn <- socketConnection(server = TRUE, port = 7890, open = "r+")
print("Reading data")
aa <- readLines(conn)
print("end reading lines")
close(conn)
pirnt("Connection closed")
}
Note: I receive a "Creating server on localhost" and a "Reading data"
in the R console, but nothing else.
The PERL client
#! /usr/bin/perl
use strict;
use Socket;
# initialize host and port
my $host = shift || 'localhost';
my $port = shift || 7890;
my $proto = getprotobyname('tcp');
my $iaddr = inet_aton($host);
my $paddr = sockaddr_in($port, $iaddr);
socket(SOCKET, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
connect(SOCKET, $paddr) or die "connect: $!";
print SOCKET "Hello \n";
close SOCKET or die "close: $!";
The PERL server
#! /usr/bin/perl -w
use strict;
use Socket;
my $port = shift || 7890;
my $proto = getprotobyname('tcp');
socket(SERVER, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
setsockopt(SERVER, SOL_SOCKET, SO_REUSEADDR, 1) or die "setsock: $!";
my $paddr = sockaddr_in($port, INADDR_ANY);
bind(SERVER, $paddr) or die "bind: $!";
listen(SERVER, SOMAXCONN) or die "listen: $!";
print "SERVER started on port $port ";
my $client_addr;
while ($client_addr = accept(CLIENT, SERVER))
{
my ($client_port, $client_ip) = sockaddr_in($client_addr);
my $client_ipnum = inet_ntoa($client_ip);
my $client_host = gethostbyaddr($client_ip, AF_INET);
print "Connection from: $client_host","[$client_ipnum] ";
while(<CLIENT>){
print "$_";
}
close CLIENT;
}