$AF_INET = 2;
$SOCK_STREAM = 1;
$sockaddr = 'S n a4 x8';
$this = pack($sockaddr, $AF_INET, 0, $thisaddr);
$that = pack($sockaddr, $AF_INET, $port, $thataddr);
($name,$aliases,$proto) = getprotobyname('tcp');
socket(S, $AF_INET, $SOCK_STREAM, $proto) || die "socket: $!";
bind(S, $this) || die "bind: $!";
if (connect(S, $that)) {
 print connetced
}
select(S); $| = 1; select(STDOUT);
 print S "$USER_VALUE CHECK $host\n";