DNS Lookup

<form action="dns.php" method="POST">
Hostname: <input type="text" name="host" />
Type: <select name="type">
<option value="a">A</option>
<option value="mx">MX</option>
<option value="ns">NS</option>
<option value="txt">TXT</option> </select>
<input type="submit" name="submit" value="Submit" />
</form>

<?

if(!empty($_POST['host']) && !empty($_POST['type'])){

    // Grab variable from form and define valid types

    $host = $_POST['host'];
    $type = strtoupper($_POST['type']);
    $validtypes=array("A","MX","NS","TXT");

    // Check that dns type is defined or allowed

    if(!defined("DNS_" . $type) or !in_array($type,$validtypes)){
       echo "Invalid DNS Type!";
    }else{

       $type = constant("DNS_" . $type);
       $rec = dns_get_record($host, $type);

       // Set result types - can be modified by using available elements from $rec array

       switch($type){
             case DNS_A:
                    $recvals=array("Hostname" => "host","Type" => "type", "IP" => "ip");
                    break;
             case DNS_MX:
                    $recvals=array("Hostname" => "host","Type" => "type", "Target" => "target", "Priority" => "pri");
                    break;
             case DNS_NS:
                    $recvals=array("Hostname" => "host","Type" => "type", "Target" => "target");
                    break;
             case DNS_TXT:
                    $recvals=array("Hostname" => "host","Type" => "type", "Record" => "txt");
                    break;
        }

      // Output results

      foreach ($rec as $arr => $num){
             foreach ($recvals as $title => $value){
                    echo $title . " : " . $num[$value] . "\n";
             }
      }

    }
} else {

     echo "Either hostname or record type is missing";
}