Document Root PHP

Question

Just to confirm, is using:

$_SERVER[\"DOCUMENT_ROOT\"]

the same as using: /

in HTML.

Eg. If current document is:

Answer 1

<a href="<?php echo $_SERVER['DOCUMENT_ROOT'].'/hello.html'; ?>">go with php</a>
    <br />
<a href="/hello.html">go to with html</a>

Try this yourself and find that they are not exactly the same.

$_SERVER['DOCUMENT_ROOT'] renders an actual file path (on my computer running as it's own server, C:/wamp/www/

HTML's / renders the root of the server url, in my case, localhost/

But C:/wamp/www/hello.html and localhost/hello.html are in fact the same file

Answer 2

Just / refers to the root of your website from the public html folder. DOCUMENT_ROOT refers to the local path to the folder on the server that contains your website.

For example, I have EasyPHP setup on a machine...

$_SERVER["DOCUMENT_ROOT"] gives me file:///C:/Program%20Files%20(x86)/EasyPHP-5.3.9/www but any file I link to with just / will be relative to my www folder.

If you want to give the absolute path to a file on your server (from the server's root) you can use DOCUMENT_ROOT. if you want to give the absolute path to a file from your website's root, use just /.

Answer 3

The Easiest way to do it is to have good site structure and write it as a constant.

DEFINE("BACK_ROOT","/var/www/");

Answer 4

Yes, on the server side $_SERVER['DOCUMENT_ROOT'] is equivalent to / on the client side.

For example: the value of "{$_SERVER['DOCUMENT_ROOT']}/images/thumbnail.png" will be the string /var/www/html/images/thumbnail.png on a server where it's local file at that path can be reached from the client side at the url http://example.com/images/thumbnail.png

No, in other words the value of $_SERVER['DOCUMENT_ROOT'] is not / rather it is the server's local path to what the server shows the client at example.com/

note: $_SERVER['DOCUMENT_ROOT'] does not include a trailing /