显示实时页面查看器的数量[重复]

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how to count the site current visitors using java script or php

I have an embedded stream on my website, but I want to pull the number of live viewers on the page. Is there a way to do this with PHP / AJAX, show the number of people currently viewing one of my webpages?

DISCLAIMER: I did something like this a LONG time ago, so here is the ugly old code (That I'm not going to put effort into making look nicer / not when I first started programming as this is just to give you an idea of how it can be done, and not to spoon feed any specific code).

$timeout = time() - (20);

$sessid_exist = mysql_query("SELECT sessid FROM bw_sessions WHERE sessid='" . session_id() . "'") or die (mysql_error());
$sessid_check = mysql_num_rows($sessid_exist);

if ($_SESSION['bw_username']) {
                $sql = mysql_query("UPDATE bw_sessions SET timestamp='" . time() . "', username='" . $_SESSION['bw_username'] . "' WHERE sessid='" . session_id() . "'");
} else {
  if($sessid_check > 0){
                $sql = mysql_query("UPDATE bw_sessions SET timestamp='" . time() . "' WHERE sessid='" . session_id() . "'");
              } else {
              $sql = mysql_query("INSERT INTO bw_sessions (id, username, sessid, timestamp, ip)
        VALUES(null, '', '" . session_id() . "', '" . time() . "', '" . $_SERVER['REMOTE_ADDR'] . "')") or die (mysql_error());
          }
}


$sql = mysql_query("SELECT distinct sessid FROM bw_sessions WHERE username='' AND timestamp >= '$timeout' ORDER BY timestamp DESC") or die (mysql_error());
$sql2 = mysql_query("SELECT distinct sessid,username FROM bw_sessions WHERE username!='' AND timestamp >= '$timeout' ORDER BY username DESC") or die (mysql_error());
$num_guests = mysql_num_rows($sql);
$num_reg = mysql_num_rows($sql2);
?>

<font size='1'>Currently Online: <br>
                        <?=$num_guests;?> Guests<br>
                        <?=$num_reg;?> Registered users

You just need to make a table and hold session_id's.. then query that table for any "recent" activity. If you want real time updates, put code above (modified to your table design) in "online.php" and call it via jquery every x seconds, or however you decide to do it.

Something like Clicky should work for you.

If you've seen it somewhere, it probably IS possible, and this sort of thing is built into most forum sofware, and it's used on a lot of websites, so it's probably not that hard.

The usual way of doing this gets the IP of a connected visitor from $_SERVER['REMOTE_ADDR'] and then writes that to a file, and adding up all the unique IP's to find out how many people are connected. This will need some sort of cleaning function to remove any IP's that are no longer connected.

The script runs on pageload, and counts visitors in a file, so if using ajax you run a PHP script polling that file every so often to update the count dynamically, or you could do it on pageload, but then ajax is'nt necessary as you could just do it with PHP.

If you don't already know how, figuring out how to run a PHP script in $.ajax is the first thing to do, then writing a function that counts visitors is probably the next.

I got 244 million hits on a search for such a script, and there's one here and here.