# server.pl
use strict;
use IO::Socket;
use IO::Select;

my $main_sock = new IO::Socket::INET(
  LocalAddr => '127.0.0.1',
  LocalPort => 1200,
  Proto     => 'tcp',
  Listen    => 1,
  ReuseAddr => 1,
);

die "Could not initialize server: $!\n"
  unless $main_sock;

print "Server has successfully initialized.\n\n";

my $r_handles = new IO::Select();
$r_handles->add( $main_sock );

while (1) {
  my ($new_r) = IO::Select->select(
    $r_handles, undef, undef, 0
  );

  foreach my $sock (@$new_r) {
    if ($sock == $main_sock) {
      my $new_sock = $sock->accept();
      $r_handles->add($new_sock);
    } else {
      my $buf = <$sock>;
      if ($buf) {
        print "$buf\n";
      } else {
        $r_handles->remove($sock);
        close $sock;
      }
    }
  }

}



# client.pl
use strict;
use IO::Socket;

my $client_id = $ARGV[0];

my $sock = new IO::Socket::INET(
  PeerAddr => '127.0.0.1',
  PeerPort => 1200,
  Proto    => 'tcp',
);

die "Could not connect to server: $!\n"
  unless $sock;

for (1 .. 5) {
  print $sock "From $client_id: Msg $_\n";
  sleep 1;
}

close $sock;