Question

I need to detect if a user is accessing my site from a certain sub-domain. How can I detect the following example and flag it using PHP? I only want to detect if “abc” is the sub-domain and nothing more, but it has to work with various other domains after “abc”.

• http://abc.domain.com/
• http://abc.domain/
• http://abc.sub.domain.com/

Yes, they’re on the “abc” sub-domain.

• http://domain.com/
• http://xyz.domain.com/
• http://www.domain/
• http://sub.domain.com/
• http://xyz.sub.domain.com/

No, they’re not.

Answer 1

This will return the subdomain:

array_shift(explode(".",$_SERVER['HTTP_HOST']));