[PHP]How do I count users online and users logged in, what method?

Question

I've made a log in script for my site, the session stuff basically look like this.

if($_SESSION['loggedin']=="Yes"){
//user online stuff
}

For all other users the session is set

$_SESSION['loggedin']=="No";

How can i display active session that are set to yes or no? should i work anything with mysql tables and use crontabs? or should i count files in tmp(session directory) on apache?

What are the best methods and how can I do it?

Answer 1

You can store the users in a database, along with their login information, and check that every time you want to authenticate a user. This is far safer than using just session variables to authenticate.

You can count the number of users that are logged in by setting a bit for the user's record when they log in and turning the bit off when they log out / session expires, and counting the number of these bits that are on to see how many people are logged in.

Answer 2

Crontab is not necessary here. You can store last activity date and time somewhere (mysql database?), and use simple select, which would show amount of users, who were active within some timeout.

This table can be used for server-side tracking of logged in users. Table may also contain some additional information, like IP address, X-Forwarded-For IP etc.

Answer 3

If you need to display the actual users currently logged in, you're better off using a column in your users mysql table to track the current login state, and doing a periodical request via a cronjob, and store that info in a .txt file so that you can do the query just once for all logged in users and share the result by including it in your rendered html. The other method (reading inside the session folder storage) is possible but more complex and probably less effective, although i haven't done any benchmarks. It just feels very hacky.