操作有误
NULL
array(1) {
  ["host"] => string(14) "igrua.afvz.com"
}
array(1) {
  [0] => array(3) {
    [0] => string(5) "igrua"
    [1] => string(4) "afvz"
    [2] => string(3) "com"
  }
}