/**
* Scan content of source url for a trackback url
*
* @return str - trackback url
*
* Adapted from Pligg.com and SocialWebCMS.com
*/
private function detectTrackback($h)
{
// Fetch the content of the original url...
$url = $h->post->origUrl;
$content = $url != 'http://' && $url != '' ? hotaru_http_request($url) : '';
$trackback = '';
if (preg_match('/trackback:ping="([^"]+)"/i', $content, $matches) || preg_match('/trackback:ping +rdf:resource="([^>]+)"/i', $content, $matches) || preg_match('/<trackback:ping>([^<>]+)/i', $content, $matches)) {
$trackback = trim($matches[1]);
} elseif (preg_match('/<a[^>]+rel="trackback"[^>]*>/i', $content, $matches)) {
if (preg_match('/href="([^"]+)"/i', $matches[0], $matches2)) {
$trackback = trim($matches2[1]);
}
} elseif (preg_match('/<a[^>]+href=[^>]+>trackback<\\/a>/i', $content, $matches)) {
if (preg_match('/href="([^"]+)"/i', $matches[0], $matches2)) {
$trackback = trim($matches2[1]);
}
} elseif (preg_match('/http:([^ ]+)trackback.php([^<|^ ]+)/i', $content, $matches)) {
$trackback = trim($matches[1]);
} elseif (preg_match('/trackback:ping="([^"]+)"/', $content, $matches)) {
$trackback = trim($matches[1]);
}
return $trackback;
}
function hotaru_http_request($url)
{
$response = "";
if (substr($url, 0, 4) != 'http') {
return 'The URL provided is missing the "http", can not continue with request';
}
$req = $url;
$pos = strpos($req, '://');
$protocol = strtolower(substr($req, 0, $pos));
$req = substr($req, $pos + 3);
$pos = strpos($req, '/');
if ($pos === false) {
$pos = strlen($req);
}
$host = substr($req, 0, $pos);
if (strpos($host, ':') !== false) {
list($host, $port) = explode(':', $host);
} else {
$port = $protocol == 'https' ? 443 : 80;
}
$uri = substr($req, $pos);
if (empty($uri)) {
$uri = '/';
}
$crlf = "\r\n";
// generate request
$req = 'GET ' . $uri . ' HTTP/1.0' . $crlf . 'Host: ' . $host . $crlf . $crlf;
error_reporting(E_ERROR);
// fetch
$fp = fsockopen(($protocol == 'https' ? 'tls://' : '') . $host, $port, $errno, $errstr, 20);
if (!$fp) {
return "BADURL";
}
fwrite($fp, $req);
while (is_resource($fp) && $fp && !feof($fp)) {
$response .= fread($fp, 1024);
}
fclose($fp);
// split header and body
$pos = strpos($response, $crlf . $crlf);
if ($pos === false) {
return $response;
}
$header = substr($response, 0, $pos);
$body = substr($response, $pos + 2 * strlen($crlf));
// parse headers
$headers = array();
$lines = explode($crlf, $header);
foreach ($lines as $line) {
if (($pos = strpos($line, ':')) !== false) {
$headers[strtolower(trim(substr($line, 0, $pos)))] = trim(substr($line, $pos + 1));
}
}
// redirection?
if (isset($headers['location'])) {
return hotaru_http_request($headers['location']);
}
return $body;
}
