function _send($data)
{
switch ($this->mode) {
case self::MODE_SSH2:
$this->ssh->_send_channel_packet(SSH2::CHANNEL_EXEC, $data);
break;
case self::MODE_SSH1:
$data = pack('CNa*', NET_SSH1_CMSG_STDIN_DATA, strlen($data), $data);
$this->ssh->_send_binary_packet($data);
}
}