#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11107384
use warnings;
use IO::Socket;
use IO::Select;
$| = 1; # auto-flush on socket

@ARGV == 2 or die "IP and Portnumber needed";
my ($server_ip,$server_port)=@ARGV;

# create a connecting socket
my $socket = new IO::Socket::INET (
    PeerHost => $server_ip,
    PeerPort => $server_port,
    Proto => 'tcp',
);
die "cannot connect to the server $!\n" unless $socket;

my $read_handler = IO::Select->new();
$read_handler->add($socket, *STDIN);
my $send_buffer;

while(1)
  {
  my @sockets_ready =$read_handler->can_read();
  foreach my $read (@sockets_ready)
    {
    my $buffer;
    if( sysread $read, $buffer, 1024 )
      {
      if( $read eq $socket )
        {
        print $buffer;
        }
      else
        {
        print $socket $buffer;
        }
      }
    else
      {
      die "socket closed";
      }
    }
  }