Reputation: 1190

Best way to get hostname with php

I have a php application that is installed on several servers and all of our developers laptops. I need a fast and reliable way to get the server's hostname or some other unique and reliable system identifier. Here's what we have thought of so far:

<? $hostname = (!empty($_ENV["HOSTNAME"])) ? $_ENV["HOSTNAME"] : env('HOSTNAME'); ?>

<? $hostname = gethostbyaddr($_SERVER['SERVER_ADDR']); ?>

<? $hostname = exec('hostname'); ?>

What do you think?

Upvotes: 59

Answers (7)

TheTechGuy

Reputation: 17354

The accepted answer of gethostname() may, in fact, give you an inaccurate value as it does in my case:

gethostname()         = my-macbook-pro     (which is my machine name)
$_SERVER['host_name'] = mysite.git         (which is my website name)

The value from gethostname() is obviously wrong. Be careful with it.

Upvotes: 2

That Realty Programmer Guy

Reputation: 1599

Whether your webserver is Apache, NGINX or otherwise; you can set the headers which are forwarded to your PHP application. While slightly safer on its own, due to browser behavior, the Origin header is useful for this scenario.

For example, with NGINX: Add an explicit set to fastcgi_param HTTP_ORIGIN either as a hard-coded string, based on $server_name or $ssl_server_name. This is done in an NGINX server block context which will ensure host strings matched with the header, but you don't pass the header directly to your app. Apache configs have the same information available in the virtual host configs.

This way, the string going to your app is predefined by your project. The main point is that user submitted headers will be checked against accepted values -- but never passed along. The existing accepted value will be passed along instead.

Upvotes: 0

Mike Grace

Reputation: 16924

I am running PHP version 5.4 on shared hosting and both of these both successfully return the same results:

php_uname('n');

gethostname();

Upvotes: 2

Pedro

Reputation: 898

You could also use...

$hostname = getenv('HTTP_HOST');

Upvotes: 3

ghbarratt

Reputation: 11711

For PHP >= 5.3.0 use this:

$hostname = gethostname();

For PHP < 5.3.0 but >= 4.2.0 use this:

$hostname = php_uname('n');

For PHP < 4.2.0 use this:

$hostname = getenv('HOSTNAME'); 
if(!$hostname) $hostname = trim(`hostname`); 
if(!$hostname) $hostname = exec('echo $HOSTNAME');
if(!$hostname) $hostname = preg_replace('#^\w+\s+(\w+).*$#', '$1', exec('uname -a'));

Upvotes: 44