Simple subdomains handler for CI3

If that works for you, then fine. But your initial post was about how to detect a subdomain and route it accordingly not how to detect a subdomain AND validate it with your app.

You have clearly thought out the problem I presented and fixed how you handle it within YOUR app. But by posting the initial snippet for others to copy without having your application logic to validate is bad practice and will leave other websites up for vulnerability.

Codeigniter is simply one of the tools you need to learn to be a successful developer. Always add more tools to your coding arsenal!