#!/usr/bin/perl -w
use strict;
use Socket; # For constants like AF_INET and SOCK_STREAM
use IO::Select;
$| = 1;
my($proto, $port , $sock , $s , @ready , $so , $addrinfo , $client , $inp);
$proto = getprotobyname('tcp');    #get the tcp protocol
socket($sock, AF_INET, SOCK_STREAM, $proto) or die "could not create socket : $!";
$port = $ARGV[0];
bind($sock , sockaddr_in($port, INADDR_ANY)) or  die "bind failed : $!";
listen($sock , 10);
print "Server is now listening ...\n";
$s = IO::Select->new();
$s->add($sock);
while(1)
{
    @ready = $s->can_read(0);
    foreach $so(@ready)
    {
        if($so == $sock)
        {
            my($client);
            $addrinfo = accept($client , $sock);
            my($port, $iaddr) = sockaddr_in($addrinfo);
            my $name = gethostbyaddr($iaddr, AF_INET);
            print "Connection accepted from $name : $port \n";
            send($client , "Hello client how are you\n" , 0);
             
            $s->add($client);
        }
        else
        {
            chop($inp = <$so>);
            chop($inp);
            print "Received -- $inp \n";
            send($so , "OK : $inp\n" , 0);
        }
    }
}
close($sock);
exit(0);