how do i create personal sub domain programmatically with php

Question

if I like to create per user sub domain , how technically do I do this ?
for example if user XXX is registered to my site and I what to associated him the sub domain h

Answer 1

You need to setup a wildcard DNS record to catch all subdomains and send them to you web server.

Then you need to setup Apache to catch all named virtual hosts and send it to a directory.

In the directory you would set htaccess to send all requests to one script which would read the sub domain from the server variables and handle it accordingly.

Answer 2

How would you create the subdomain manually?

Good. Now automate it.

Answer 3

If you want mydomain.com/xxx, then that's just a folder. Some hosts will also take mydomain.com/xxx and automatically make xxx.mydomain.com point to it without needing any configuration on your part. Might want to check that this isn't already the case for you.