criffoh at gmail dot com is right. Before you check domain, you must convert to ascii with idn_to_ascii function:
http://us2.php.net/manual/en/function.idn-to-ascii.php .
var_dump(checkdnsrr('ñandu.cl', 'A')); // returns false
var_dump(checkdnsrr(idn_to_ascii('ñandu.cl'), 'A')); // return true
checkdnsrr
(PHP 4, PHP 5, PHP 7, PHP 8)
checkdnsrr — 指定したインターネットホスト名もしくは IP アドレスに対応する DNS レコードを検索する
パラメータ
-
hostname -
hostnameは、ドットで 4 つに分けられた形式の IP アドレスか、あるいはホスト名です。 -
type -
typeは、A, MX, NS, SOA, PTR, CNAME, AAAA, A6, SRV, NAPTR, ANY のどれか一つです。
戻り値
レコードが見つかった場合に true、
何も見つからないかエラーが発生した場合に false を返します。
参考
- dns_get_record() - ホスト名に関連する DNS リソースレコードを取得する
- getmxrr() - 指定したインターネットホスト名に対応する MX レコードを取得する
- gethostbyaddr() - 指定した IP アドレスに対応するインターネットホスト名を取得する
- gethostbyname() - インターネットホスト名に対応するIPv4アドレスを取得する
- gethostbynamel() - 指定したインターネットホスト名に対応するIPv4アドレスのリストを取得する
- the named(8) manual page
add a note
User Contributed Notes 6 notes
Krisztin Ferenczi ¶
11 years ago
Martin ¶
8 years ago
Important Warning:
You need to add a dot to the end of the host name to make a fully qualified domain name.
To see why, try executing the following pieces of code:
$d1="gmail.con";
$d2="gmail.con.";
$r1=checkdnsrr($d1, "MX");
$r2=checkdnsrr($d2, "MX");
var_dump($r1);
var_dump($r2);
You will see that without the dot it claims that the domain "gmail.con" is valid.
Note that if you time the "checkdnsrr()" calls you will also see it takes longer without the dot because it treats it as a relative domain and does several tries based on the host name it is running on.
NB: in case you're interested, being treated as a relative domain explains what is happening. If your host is "example.com" the relative domain will eventually resolve to "gmail.con.com." which can be looked up, hence it wrongly claims "gmail.con" exists
Patrick ¶
19 years ago
This is a little code example that will validate an email address in two ways:
- first the general syntax of the string is checked with a regular expression
- then the domain substring (after the '@') is checked using the 'checkdnsrr' function
<?php
function validate_email($email){
$exp = "^[a-z\'0-9]+([._-][a-z\'0-9]+)*@([a-z0-9]+([._-][a-z0-9]+))+$";
if(eregi($exp,$email)){
if(checkdnsrr(array_pop(explode("@",$email)),"MX")){
return true;
}else{
return false;
}
}else{
return false;
}
}
?>
n at zay dot uk ¶
3 years ago
I always think you should state the blindingly obvious.
A function that contains checkdnsrr will return false without an internet connection.
So in a production environment you need an active internet connection to return a true result with a valid email address.
criffoh at gmail dot com ¶
11 years ago
Is not possible validate domains with 'ñ' for my country.
In my country is possible to register domain using 'ñ' character. For example:
ñandu.cl
http://nic.cl/cgi-bin/dom-CL?q=%F1andu
If I use this function to check DNS record, it return false, but the domain already exists:
var_dump(checkdnsrr('ñandu.cl', 'A')); // returns false
dobs ¶
6 years ago
$this->_buf - for bulk check cache
function ValidateEmail($email)
{
list($user, $domain) = explode('@', $email);
if (!filter_var($email, FILTER_VALIDATE_EMAIL) !== FALSE)
return 0;
if (isset($this->_buf[$domain]))
return $this->_buf[$domain];
if (checkdnsrr($domain) === FALSE) {
$this->_buf[$domain] = 0;
return 0;
}
$this->_buf[$domain] = 1;
return 1;
}
