How to prevent sessions from being saved in files?

Use a custom session handler implementing the SessionHandlerInterface.

1. Create a class that implements the methods: open, close, read, write, destroy, gc, and create_sid.
2. Inside these methods, implement logic to save and read session data using another database (e.g., MySQL, PostgreSQL, Redis, Memcached) or another storage mechanism.
3. Register this handler using the session_set_save_handler() function.

Example class for saving in Redis:

<?php

class RedisSessionHandler implements SessionHandlerInterface
{
    private $redis;
    private $ttl;

    public function __construct(Redis $redis, int $ttl = 1800)
    {
        $this->redis = $redis;
        $this->ttl = $ttl;
    }

    public function open(string $path, string $name): bool
    {
        // Can be used for initialization if needed
        return true;
    }

    public function close(): bool
    {
        // Can be used for cleanup if needed
        return true;
    }

    public function read(string $id): string|false
    {
        $data = $this->redis->get("session:$id");
        return $data === false ? '' : $data; // Return empty string if no data
    }

    public function write(string $id, string $data): bool
    {
        return $this->redis->setex("session:$id", $this->ttl, $data);
    }

    public function destroy(string $id): bool
    {
        return $this->redis->del("session:$id") > 0;
    }

    public function gc(int $max_lifetime): int|false
    {
        // Garbage collection in Redis happens automatically via TTL
        return 0;
    }

    public function create_sid(): string
    {
        // You can use the standard implementation or generate your own
        return bin2hex(random_bytes(16));
    }
}

Registering the handler:

<?php

// Assuming the Redis object is already created and connected
$redis = new Redis();
$redis->connect('127.0.0.1', 6379);

$handler = new RedisSessionHandler($redis);
session_set_save_handler($handler, true); // true for automatic closing

session_start(); // Start the session

Other options:

• Use a ready-made session handler implementation from a framework or third-party library.
• Change the session.save_handler directive value in php.ini to the desired handler (e.g., redis or memcached) if the corresponding PHP extension is installed and configured.