A little script to generate Google site maps for an ElkArte forum.

googlefeed.php

<?php

// Put the path to your forum install, with a trailing slash.
// This is the on-disk directory where index.php for your board 
// lives.
$forum_path = "/var/www/html/forum/";

// Number of posts to show in a given syndication run
$num_posts = 300;

// We need our configuration!
require $forum_path."Settings.php";

$dsns = $db_type . ':dbname=' . $db_name . ';host=' . $db_server . (!empty($db_port) ? ';port=' . $db_port : '');

$db = new PDO($dsns, $db_user, $db_passwd);

$db->exec('SET NAMES utf8');

$tblprefix = $db_prefix;
$whereclause = "id_board <> 0";

$query = 'SELECT * FROM '.$tblprefix.'topics WHERE '.$whereclause.' ORDER BY id_last_msg DESC LIMIT 1';

$result = $db->query($query);
$row = $result->fetch(PDO::FETCH_ASSOC);

$query = 'SELECT poster_time FROM '.$tblprefix.'messages WHERE id_msg = '.$row['id_last_msg'];

$result = $db->query($query);
$row = $result->fetch(PDO::FETCH_ASSOC);

// ...and get a timestamp for it, to use as our
// RSS 2.0 lastBuildDate
$latestpoststamp = $row['poster_time'];
$latestpost = gmdate('D, d M Y H:i:s \G\M\T', $latestpoststamp);

// Build some headers
$xmlheader = "<?xml version='1.0' encoding='UTF-8'?>";
$channelheader = '
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">';

// Now we grab a list of the forums, in order to get
// names and permissions from them.
$query = 'SELECT * FROM '.$tblprefix.'boards ORDER BY id_board';

$result = $db->query($query);

$forums = array();
$forumperms = array();

while ($row = $result->fetch(PDO::FETCH_ASSOC)) {
   $perms = explode(',', $row['member_groups']);
   $forums[$row['id_board']] = $row['name'];
   $forumperms[$row['id_board']] = $perms;
}

$read_group = "Guests";

// And then we go find user 0, namely the Guest user,
// and get their group permissions for later use.
$query = 'SELECT * FROM '.$tblprefix.'membergroups WHERE group_name=\''.$read_group.'\''; 
$result = $db->query($query);

$anongroup = -1;

if ($row = $result->fetch(PDO::FETCH_ASSOC))
{
	$anongroup = $row['id_group'];
}

$whereclause = "";

// Now we query for posts!  Yay!
$query = 'SELECT t.id_topic, t.id_board, t.id_last_msg, t.num_replies, mf.subject, ml.poster_time FROM '.$tblprefix.'topics AS t INNER JOIN '.$tblprefix.'messages AS mf ON mf.id_msg = id_first_msg INNER JOIN '.$tblprefix.'messages AS ml ON ml.id_msg = id_last_msg '.$whereclause.' ORDER BY id_last_msg DESC LIMIT '.$num_posts;

$result = $db->query($query);

$itembodies = '';

// ...with our posts, we iterate across them.
while ($row = $result->fetch(PDO::FETCH_ASSOC)) {

   // We build a little array of permissions for the forum this
   // post is in...
   $forum_id = 0;
   $forum_id = $row['id_board'];
   $title = htmlentities($row['subject'], ENT_QUOTES, "UTF-8");

   $readgroups = $forumperms[$forum_id];

   // ...and check whether the Guest can read in this forum.
   if (in_array($anongroup,$readgroups)) {

      $lastpage = (intval(($row['num_replies'] + 1) / 25)) * 25;
      $postdate = date(DATE_W3C, $row['poster_time']);

      if ($lastpage == 0) {
      	$posturl = $boardurl.
                   '/index.php/topic,'.$row['id_topic'].'.0.html';
      } else {
      	$posturl = $boardurl.
                   '/index.php/topic,'.$row['id_topic'].'.'.$lastpage.'.html';
      }

      $posturl = htmlentities($posturl, ENT_QUOTES, "UTF-8"); 

      // Build the actual RSS text for the item...
      $thisitem = "
         <url>
            <loc>{$posturl}</loc>
            <lastmod>{$postdate}</lastmod>
         </url>";

      
      // ..and concatenate it onto the item bodies.
      $itembodies .= $thisitem;
   }
}


$channelclose = '
</urlset>
';

// Now we build an actual RSS feed out of all the pieces we've
// collected.
$rssbody = 	$xmlheader.
		$channelheader.
		$itembodies.
		$channelclose;

// Look, ma, honoring HTTP headers!
$rsslength = strlen($rssbody);

header("Content-Type: text/xml; charset=utf-8");
header("Content-Length: ".$rsslength);
header("Cache-Control: no-cache");
header("Last-Modified: ".$latestpost);
echo $rssbody;

?>