[RESOLVED] Need help understaning $ SERVER['document_root']

[Paul_help_]

Hi guys.

I need help understanding what this returns:

$SERVER['document_root']

Am I correct in thinking that it returns the top level path of the folder where a website it kept?

And if so, lets say I had a folder inside a folder, inside another folder, and my php file was inside the bottommost (child) folder. And my php file made use of:

SERVER['document_root']

... Would this return a path to the top level folder?

If so, this sounds really god dam handy!

Paul.

[NogDog]

Somewhere in your web server configuration, there is a setting that says what file system directory is the root directory for the (sub-)domain in question. So if, for example, "example.com" is pointed to "/var/www/domains/example" on your web server, then that's what $SERVER['DOCUMENT_ROOT'] (case-sensitive!) will point to. If you want to reference a file that is in a sub-directory, you could reference something like this:

require_once $_SERVER['DOCUMENT_ROOT'].'/sub_dir/file_name.php';

This would, in this example, then be trying to read the following file:

/var/www/domains/example/sub_dir/file_name.php

[Paul_help_]

Thanks.

But what I need to know is - can SERVER['document_root'] .... be used to reference the root folder instead of having to use double periods (..) and a literal path, when referencing the root folder which could be several levels above the one you are currently in?

[NogDog]

If you wanted to access files outside of the web root, then you would have to use the ".." method to work your way up the file system path.

require_once $_SERVER['DOCUMENT_ROOT'].'/../includes/some_file.php';

And then that means you need to be consistent about where you install those include files (or whatever) in your different environments.

[dalecosp]

And you may also have to deal with filesystem permissions issues, and the fact that the server software absolutely cannot access file above a certain directory (In Apache this is "ServerRoot") without some serious hackish stuff being implemented (setting ServerRoot too high is an absolute no-no ... as an example, maybe some things outside ServerRoot could be symbolically linked, and there is mod_userdir to allow access to $HOME if I understand what it's supposed to do correctly ...)