use strict;
use warnings;

use IO::Socket::INET;
use Socket qw(:DEFAULT :crlf);

$|++;

my $hostname = 'localhost';
my $port = 2001;

my $sock = IO::Socket::INET->new(PeerAddr => $hostname,
                   PeerPort => $port,
                   Proto    => 'tcp')
        or die "Can't connect: $!";

$sock->autoflush(1);

print $sock "Hello, World!$CRLF";  # Using $CRLF is more portable

close $sock;