Question

我需要从一个域中获取MX记录，但只有一个优先级最高（最低）的记录。

我玩了相当多的游戏，但无法弄清楚如何只返回一个结果。

   $results = dns_get_record($domain, DNS_MX);

   foreach ($results as $result)
   {
    $A = dns_get_record($result['target'], DNS_A);
    foreach ($A as $ip)
    { 
             echo $ip['ip'];
    }
   }

这给了我最终的收获，但是对于域拥有的每条MX记录来说。

如果有人能指出我正确的方向，那就太好了！

干杯！

Answer 1

使用array_column()函数收集所有优先级，然后使用array_filter提取最小的优先级：

// get all the results
$results = dns_get_record($domain, DNS_MX);
// find the lowest value in the "pri" column
$target_pri = min(array_column($results, "pri"));
$highest_pri = array_filter(
    $results,
    // keep anything that matches the lowest (could be more than one)
    function($item) use($target_pri) {return $item["pri"] === $target_pri;}
);
// now loop through each of them, finding all their IP addresses
foreach ($highest_pri as $mx) {
    echo "$mx[target]: ";
    $results = dns_get_record($mx["target"], DNS_A);
    foreach ($results as $a) {
        echo "$a[ip] ";
    }
    echo "\n";
}

从PHP检索优先级最低的MX记录

1 个答案: