//粗略计算在线时间,bug:ip相同（局域网->外部网）者，只记录一人。不过几率很少
session_start();
//超时时间
$out_time=300;//60*5
$uesr_name=$_SESSION['uesr_name'];
$now=time();
$online="db_online";
$ip=$_SERVER["REMOTE_ADDR"];
mysql_connect("localhost","root","");
mysql_select_db("数据库");
//删除过时用户.
mysql_query("delete from `$online` where ($now-`time`)>$out_time or `name`='$uesr_name' or `ip`='$ip' ");
if($uesr_name){
mysql_query(" INSERT INTO `$online` (`ip`, `time`, `name`) VALUES ('$ip','$now','$uesr_name') ");
}else{
mysql_query(" INSERT INTO `$online` (`ip`, `time`, `name`) VALUES ('$ip','$now','游客') ");
}
?>
