PHP如何获取子域的根URL

Question

I used to have my website into a domain like : www.mydomain.com
But now i've created a subdomain 'test' : www.test.mydomain.com and i moved the whole project files there.

So far so good, the problem is that on my php libraries where i call db connection etc, i use the $_SERVER['DOCUMENT_ROOT'] which gives me the URL without the subdomain , ex

$file = $_SERVER['DOCUMENT_ROOT'];//gives me www.mydomain.com 

But i need to get the root with the subdomain, like : www.test.mydomain.com

I dont want to make a trick like to split the url and add the subdomain thing.

Any help would be appreciated.

Answer 1

You can try both:

$_SERVER["SERVER_NAME"]

$_SERVER['HTTP_HOST']

Both will return the domain with the subdomain.

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$_SERVER["SERVER_NAME"]

The name of the server host under which the current script is executing. If the script is running on a virtual host, this will be the value defined for that virtual host.

$_SERVER['HTTP_HOST']

Contents of the Host: header from the current request, if there is one.

You can read up on the difference between $_SERVER["SERVER_NAME"] and $_SERVER['HTTP_HOST'] at HTTP_HOST vs. SERVER_NAME .

$_SERVER['DOCUMENT_ROOT'] will not work as stated in documentation

The document root directory under which the current script is executing, as defined in the server's configuration file.

More information on $_SERVER at http://php.net/manual/en/reserved.variables.server.php .

Answer 2

$_SERVER['DOCUMENT_ROOT'] does not contain the server name! It contains - as the name says - the DOCUMENT_ROOT . This is the directory where the filesystem starts that your webserver serves.

You should try $_SERVER['SERVER_NAME'] instead. This should work if your virtual server setup is correct.

Answer 3

Finally, after two hours searching , I spoke to the system admin and he cleared that he actually created an alias domain which it actually reacts as : www.test.mydomain.com .

I guess that is why i get the www.mydomain.com without the subdomain when i call $_SERVER['DOCUMENT_ROOT'] .

Thanks, case closed.