CODEWITHSUNDEEP
phpsubdomainhostname
Zoolander
Zoolander

Reputation: 2363

How to detect "abc" in abc.domain.com or abc.sub.domain.com using PHP?

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".

Yes, they're on the "abc" sub-domain.

No, they're not.

Upvotes: 1

Views: 272

Answers (5)

Mohit Dhanjani
Mohit Dhanjani

Reputation: 19

You can configure your web server to redirect all your subdomains to a single PHP file where you can make up an error or redirect the user via the header() function with something like...

header('Location: http://domain.com');

Also, because you're sure that the particular PHP file is being accessed because of a subdomain, then you can do something like...

$url = $_SERVER['SERVER_NAME'];
list($subdomain) = explode('.', $url, 2);
$subdomain = trim(strtolower($subdomain));

And then use the $subdomain variable the way you like (eg. print it)...

echo $subdomain;

Just in case. For the Apache configuration, you need to modify the VirtualHost for redirecting your subdomains to a PHP file for processing.

<VirtualHost *:80>
ServerAlias *.domain.com
DocumentRoot /website/directory/page.php
</VirtualHost>

NOTE

1.) To restart Apache.
2.) Apache will give you warning that the directory does NOT exist. It's true, because you are providing a file path instead of a directory path. But this will work.

Upvotes: 0

JorgeeFG
JorgeeFG

Reputation: 5981

<?php

if( explode( '.', $_SERVER['SERVER_NAME'] )[0] === 'abc' ) {
    //do something
}
?>

That will explode server name in parts divided by ., so it will compare the first part of the domain name with the string abc.

The explode(x,x)[N] thing is only possible in PHP 5.4+ (or 5.3+, I don't remember correctly).

Upvotes: 1

Mike Brant
Mike Brant

Reputation: 71422

You can access the host name from within the $_SERVER superglobal like this:

$domain = $_SERVER['HTTP_HOST']

There are then any number of ways to determine if this value begins with abc. The easiest might simply be stripos

if(stripos('abc', $domain) === 0) {
    // you found it
}

Note that the use of === instead of == is VERY important here. If you used == and the substring was not found in $domain, stripos would return false, which with == 0 would evaluate as true in your conditional.

Upvotes: 1

JohnB
JohnB

Reputation: 1231

This will return the subdomain: 

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

Upvotes: 2

Ren&#233; H&#246;hle
Ren&#233; H&#246;hle

Reputation: 27325

You can check the HTTP_HOST or SERVER_NAME in your $_SERVER variable.

<?php
if(strpos($_SERVER['SERVER_NAME'], 'abc.domain.com') !== false) {
    //do something
}
?>

Upvotes: 2

Related Questions