Network 函数
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gethostbynamel

(PHP 4, PHP 5)

gethostbynamel — Get a list of IPv4 addresses corresponding to a given Internet host name

说明

array gethostbynamel ( string $hostname )

Returns a list of IPv4 addresses to which the Internet host specified by hostname resolves.

参数

hostname

The host name.

返回值

Returns an array of IPv4 addresses or FALSE if hostname could not be resolved.

范例

Example #1 gethostbynamel() example

<?php
$hosts = gethostbynamel('www.example.com');
print_r($hosts);
?>

以上例程会输出：

Array
(
    [0] => 192.0.34.166
)

参见

Network 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: Get a list of IPv4 addresses corresponding to a given Internet host name

用户评论:

info at methfessel-computers.de (29-Sep-2006 11:27)

The solution is simpel. Just add a . (point) to the end of the URL for correct name resolving.

Without this point PHP thinks it's a subdomain of your local domain and so returns the "local-IP".

webdev at concraption dot com (19-Sep-2005 07:25)

In PHP 5.0.4, gethostbynamel returns an empty string instead of false if the lookup fails. A simple workaround for this error is to use is_array() in an IF block:

<?
$hosts = gethostbynamel($hostname);
if (is_array($hosts)) {
     echo "Host ".$hostname." resolves to:<br><br>";
     foreach ($hosts as $ip) {
          echo "IP: ".$ip."<br>";
     }
} else {
     echo "Host ".$hostname." is not tied to any IP.";
}
?>

Skyld at o2 dot co dot uk (25-Sep-2004 09:45)

Obviously, in some cases, not all IPs are likely to be useful while checking a hostname. Sometimes also, not all IPs will work. This code will check for the first WORKING IP from the list. Or at least it should - I haven't had time to test it yet.
Needs domain parameter, and port and max IPs to check are optional.
If port is not set, it will check HTTP port 80, and if max IPs to check is not set, it will only check the first 10 IPs from the list.
Hope it helps someone.

<?php
  function checkhostlist($domain, $port = 80, $maxipstocheck = 10) {
  $hosts = gethostbynamel($domain);
    for ($chk=0;$chk<$maxipstocheck;$chk++) {
      if (isset($hosts[$chk])) {
        $th = fsockopen($domain, $port);
        if ($th) {
          fclose($th);
          return $hosts[$chk];
          break;
        }
      }
    }
  }
?>