Member Avatar for Awah Mohamed

hey people. i am asking if it is posible to check for the user status using php. i mean to know if the user if online or offline.
i am trying to build a chatting system that alow me to know who is online and who is offline.

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  • Latest Post Latest Post by 84hd0ns

Dani AI

Generated

asked how to tell who is online. correctly pointed at WebSockets, showed a simple file approach, and urged a database + timeout. Two practical paths are common:

  1. Heartbeat (simplest for PHP): have a last_activity column and update it from the browser every N seconds. Treat any row with last_activity newer than your threshold (for example, 60–120s) as "online". This is reliable, works behind normal web servers, and is easy to secure.

Example schema:

CREATE TABLE users (
  id INT AUTO_INCREMENT PRIMARY KEY,
  username VARCHAR(100) NOT NULL,
  last_activity DATETIME DEFAULT NULL
);

Heartbeat endpoint (PHP, using PDO):

<?php
session_start();
if (empty($_SESSION['user_id'])) { http_response_code(401); exit; }
$pdo = new PDO(...);
$stmt = $pdo->prepare('UPDATE users SET last_activity = NOW() WHERE id = ?');
$stmt->execute([(int)$_SESSION['user_id']]);
?>

Client ping (simple JS):

setInterval(function(){
  fetch('/heartbeat.php', { method: 'POST', credentials: 'include' }).catch(()=>{});
}, 30000); // every 30s

List online users:

$stmt = $pdo->prepare(
  "SELECT id, username FROM users WHERE last_activity > DATE_SUB(NOW(), INTERVAL 90 SECOND)"
);
$stmt->execute();
$online = $stmt->fetchAll(PDO::FETCH_ASSOC);
  1. WebSockets (recommended for full real-time chat): avoids polling and gives instant two-way updates, but requires a socket-capable server (persistent connections), more setup, and careful scaling. If a WebSocket demo (echo page) fails as @Member#120589 saw, common causes are: server not running, mixed-content (ws vs wss on HTTPS), proxy/firewall blocking, or incorrect endpoint.

Notes and cautions: always authenticate the heartbeat endpoint (session_start()), use prepared statements, pick heartbeat interval and threshold sensibly (threshold ~2x interval), and consider Redis/TTL for high scale to avoid constant DB writes.

Recommended Answers

All 6 Replies

Member Avatar for Awah Mohamed

i guess this is one of the things i want to know. but now i got another question which is how do i use this technology?
and i am asking how to know who is online like facebook.
you can see a list of the people who are online and chat with them. so this is what i am asking about

Member Avatar for Member #120589

websocket.org echo example does nothing for me. Says my browser supports it (chrome10 Win), but nothing happens on connect.

Member Avatar for 84hd0ns

Hi

maybe you could try...

when the user logs in:

$user = "logged-in/$username";
$user = fopen($user, 'w') or die('ERROR');
fclose($page);

on logout:

unlink($username);

to list users:

$users = sort(glob('logged-in/*'));
foreach ($users as $user) {
  print $user; 
  print '<br />';
}

good luck :)

Calum

Member Avatar for chrishea

In order to track users, you'll need some sort of logon process. The previous post provides a low-end approach to doing this. This may satisfy your needs, otherwise you'll want to look at using a database to keep the user information, including their login status. You need a process to force a logoff for anyone who is inactive for a set period of time. Otherwise, everyone will eventually show as logged on / active.

Edited by chrishea because: n/a
Member Avatar for 84hd0ns

good point chrishea; i'm not very familiar with mysql... lol, thats why my cms is flat file!

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