WordPress/wp-admin/update-links.php

<?php
/**
 * Send blog links to pingomatic.com to update.
 *
 * You can disable this feature by deleting the option 'use_linksupdate' or
 * setting the option to false. If no links exist, then no links are sent.
 *
 * Snoopy is included, but is not used. Fsockopen() is used instead to send link
 * URLs.
 *
 * @package WordPress
 * @subpackage Administration
 */

/** Load WordPress Bootstrap */
require_once('../wp-load.php');

/** Load Snoopy HTTP Client class */
require_once( ABSPATH . 'wp-includes/class-snoopy.php');

if ( !get_option('use_linksupdate') )
	wp_die(__('Feature disabled.'));

$link_uris = $wpdb->get_col("SELECT link_url FROM $wpdb->links");

if ( !$link_uris )
	wp_die(__('No links'));

$link_uris = urlencode( join( $link_uris, "\n" ) );

$query_string = "uris=$link_uris";

$http_request  = "POST /updated-batch/ HTTP/1.0\r\n";
$http_request .= "Host: api.pingomatic.com\r\n";
$http_request .= 'Content-Type: application/x-www-form-urlencoded; charset='.get_option('blog_charset')."\r\n";
$http_request .= 'Content-Length: ' . strlen($query_string) . "\r\n";
$http_request .= 'User-Agent: WordPress/' . $wp_version . "\r\n";
$http_request .= "\r\n";
$http_request .= $query_string;

$response = '';
if ( false !== ( $fs = @fsockopen('api.pingomatic.com', 80, $errno, $errstr, 5) ) ) {
	fwrite($fs, $http_request);
	while ( !feof($fs) )
		$response .= fgets($fs, 1160); // One TCP-IP packet
	fclose($fs);

	$response = explode("\r\n\r\n", $response, 2);
	$body = trim( $response[1] );
	$body = str_replace(array("\r\n", "\r"), "\n", $body);

	$returns = explode("\n", $body);

	foreach ($returns as $return) :
		$time = substr($return, 0, 19);
		$uri = preg_replace('/(.*?) | (.*?)/', '$2', $return);
		$wpdb->query( $wpdb->prepare("UPDATE $wpdb->links SET link_updated = %s WHERE link_url = %s", $time, $uri) );
	endforeach;
}
?>