php实现的在线人员函数库

　　
//增加用户
functionAddUser($username){
global$db;
$Ip=getenv(REMOTE_ADDR);
$Ip1=getenv(HTTP_X_FORWARDED_FOR);
if(($Ip1!=)&&($Ip1!=unknown))$Ip=$Ip1;
$current_time=date(Y-m-dH:i:s);
$SQL=selectuserfromclass_onlinewhereuser=$username;
$res=mysql_query($SQL,$db);
$row=@mysql_num_rows($res);
if($row==0){
$SQL=insertintoclass_online(user,ip,lasttime)values($username,$Ip,$current_time);
mysql_query($SQL,$db);
}
}
//更新在线用户名单
functionUpdateMember(){
global$db;
$SQL=deletefromclass_onlinewhereUNIX_TIMESTAMP()-UNIX_TIMESTAMP(lasttime)>180;//3分钟不活动则退出
//echo$SQL;
mysql_query($SQL,$db);
}
//更新在线状态
functionUpdateOnline($username){
global$db;
$current_time=date(Y-m-dH:i:s);;
$SQL=updateclass_onlinesetlasttime=$current_timewhereuser=$username;
$res=mysql_query($SQL,$db);
}
//删除用户
functionOutOneUser($user){
global$db;
$SQL=deletefromclass_onlinewhereuser=$user;
mysql_query($SQL,$db);
returntrue;
}
//检查是否在线
functionCheckUser($user){
global$db;
$SQL=selectuserfromclass_onlinewhereuser=$user;
$res=mysql_query($SQL,$db);
$row=mysql_num_rows($res);
if($row>0)returntrue;
elsereturnfalse;
}
//取在线名单
functionReadOnlineName(){
global$db;
$SQL=select*fromclass_online;
$res=mysql_query($SQL,$db);
while($row=mysql_fetch_array($res)){
$result[]=$row[user];
}
return$result;
}
//********************在线人员函数库***************end