[kh99]

I was going to use this for something I was working on: create a plugin with hook location global_complete and this code:

if ($vbulletin->userinfo['userid'] AND $vbulletin->session->created)
{
    $fp = @fopen('memberips.log', 'a');    // <--- add path to writable directory
    if (!empty($fp))
    {
        fwrite($fp, IPADDRESS . ',' . $vbulletin->userinfo['userid'] . ',' . $vbulletin->db->escape_string($vbulletin->userinfo['username']) . "\n");
        fclose($fp);
    }
}

Note that you probably have to add a path to the front of the file name in fopen() to put the log file in a writable directory.

In any case, this logs the user name, id, and ip whenever a session is created. You would probably want to add the data/time to this.

Note: I think this will be OK but I didn't try it on a busy site. I also don't know if the info might somehow already be available from the web server logs.

ETA: of course you could also add a check for the userid if you only want to log that one user.