01.<?php
02.$Session_name = "default";
03.$host = "localhost";
04.$username = "root";
05.$password = "050432";
06.$database = "student";
07.$table = "useronline";
08.
09.
10.
11.if ($Session_name == "default") {
12.session_start();
13.}
14.else {
15.session_name("$Session_name");
16.session_start("$Session_name");
17.}
18.
19.$SID = session_id();
20.$time = time();
21.$dag = date("z");
22.$nu = time()-900;
23.
24.
25.mysql_connect ($host, $username, $password) OR DIE ("Could not connect to MySQL");
26.mysql_select_db($database) OR DIE ("Can't select database.");
27.
28.
29.$sidcheck = mysql_query("SELECT count(*) FROM $table WHERE user_id='$SID'");
30.$sid_check = mysql_result($sidcheck,0);
31.
32.if ($sid_check == "0") {
33.
34.mysql_query("INSERT INTO $table VALUES ('$SID','$time','$dag','".$_SESSION["m_user"]."')");
35.} else {
36.
37.mysql_query("UPDATE $table SET time='$time' WHERE user_id='$SID'");
38.}
39.
40.
41.$count_users = mysql_query("SELECT count(*) FROM $table WHERE time>$nu AND day=$dag");
42.$users_online = mysql_result($count_users,0);
43.echo $users_online;
44.
45.
46.mysql_query("DELETE FROM $table WHERE time<$nu");
47.mysql_query("DELETE FROM $table WHERE day != $dag");
48.
49.mysql_close();
50.
51.?>
