Description
   PEAR::Net_DNSBL provides an easy way to check if a given Host or URL
   is listed on an DNS-based Blackhole List (DNSBL, Real-time Blackhole
   List or RBL) or Spam URI Realtime Blocklist (SURBL).
  
   Please not that this currently only works with IPv4 IPs.
  
Usage
    Let's start with a simple example to check if the remote host is
    listed in two blacklists:
    
<?php
require_once 'Net/DNSBL.php';
$dnsbl = new Net_DNSBL();
$remoteIP = $_SERVER['REMOTE_ADDR'];
$remoteIP = '81.70.69.193';
$dnsbl->setBlacklists(array('sbl-xbl.spamhaus.org', 'bl.spamcop.net'));
if ($dnsbl->isListed($remoteIP)) {
    // do something
}
?> | 
  
    This example shows how to check if an URL is listed in a SURBL:
    
<?php
require_once 'Net/DNSBL/SURBL.php';
$surbl = new Net_DNSBL_SURBL();
if ($surbl->isListed($addData['url'])) {
    // do something
}
?> | 
    An example how to extract URLS from a text can be found on
    http://www.phpfreaks.com/quickcode/Extract_All_URLs_on_a_Page/15.php
    and be used this way:
    
<?php
foreach ($extracted_urls as $surbl_check_url) {
    if ($surbl->isListed($surbl_check_url)) {
        // do something
        break;
    }
}
?> | 
  
    Let's get some details, if our host is listed:
    
<?php
require_once 'Net/DNSBL.php';
$dnsbl = new Net_DNSBL();
$dnsbl->setBlacklists(array('sbl-xbl.spamhaus.org', 'bl.spamcop.net'));
if ($dnsbl->isListed($_SERVER['REMOTE_ADDR'])) {
   var_dump($dnsbl->getDetails($_SERVER['REMOTE_ADDR']));
   var_dump($dnsbl->getListingBl($_SERVER['REMOTE_ADDR']));
   var_dump($dnsbl->getListingRecord($_SERVER['REMOTE_ADDR']);
}
?> |