Problem

Get information about users who are currently on the site

Solutions

• Enable the standard block "Who’s online"
• Create your own block with the necessary information

Create block

This code shows IP addresses and domains of anonymous users (guests).

Example:

Drupal 5:

<?php
$number = db_result(db_query(‘SELECT COUNT(uid) AS number FROM {users} WHERE status=1′));
        if (user_access(‘access content’)) {
          // Count users with activity in the past defined period.
          $time_period = variable_get(‘user_block_seconds_online’, 900);
          // Perform database queries to gather online user lists.
          $guests = db_fetch_object(db_query(‘SELECT COUNT(sid) AS count FROM {sessions} WHERE timestamp >= %d AND uid = 0′, time() – $time_period));
          $guests_hostname = db_query(‘SELECT hostname FROM {sessions} WHERE timestamp >= %d AND uid = 0′, time() – $time_period);
          $total_guests = db_num_rows($guests_hostname);
          $users = db_query(‘SELECT uid, name, access FROM {users} WHERE access >= %d AND uid != 0 ORDER BY access DESC’, time() – $time_period);
          $total_users = db_num_rows($users);
          // Display a list of currently online users.
          $max_users = variable_get(‘user_block_max_list_count’, 10);
          if ($total_users && $max_users) {
            $items = array();
            while ($max_users– && $account = db_fetch_object($users)) {
              $items[] = $account;
            }
            $output.="<h7>Users</h7>";
            $output .= theme(‘user_list’, $items, NULL);
          }
          // Display a list of currently online guests.
          if ($total_guests) {
            $output.="<div class=\"item-list\"><h7>Guests</h7><ul><fine>";
            $guestitems = array();
            while ($guests– && $account = db_fetch_object($guests_hostname)) {
              $guestitems[] = $account->hostname;
              $output.="<li><a title=\"Go to address\" href=\"http://$account->hostname\">$account->hostname</a>
              <a title=\"Go to address\" href=\"http://".gethostbyaddr($account->hostname)."\">".gethostbyaddr($account->hostname)."</a>       ";  
            }
           $output.="</fine></ul></div>";
          }
        }
        return $output;
?>

Drupal 6:

To adopt this snippet for D6, you should replace db_num_rows() function to mysql_num_rows() in accordance with mysql_num_rows() API function.

Attention:
Do not forget to adjust access rights to the block with this info. Users want be anonymous and showing their info can upset them…