问题
is this pointing to the directory where the current file is executed?
回答1:
No, it points to the root of your webserver - the topmost folder of your website.
If you want the directory of the current file, use:
dirname(__FILE__);
回答2:
From http://php.net/manual/en/reserved.variables.server.php
'DOCUMENT_ROOT' The document root directory under which the current script is executing, as defined in the server's configuration file.
回答3:
Maybe, depending on how the server is set up. A much better method is:
echo dirname(__FILE__); // return the absolute file-path to where the current PHP file is
回答4:
No, it's not,
DOCUMENT_ROOT points to the root directory of your webserver, while PATH_INFO points to the directory where the current file is executed.
回答5:
The document root directory under which the current script is executing, as defined in the server's configuration file.
as the name implies it's a root directory.
回答6:
Yes it is. It's a path relative to the root of your server (not your document root) that describes the directory of the current script. It does not have a trailing slash.
回答7:
'DOCUMENT_ROOT'
The document root directory under which the current script is executing, as defined in the server's configuration file.
http://www.php.net/manual/en/reserved.variables.server.php
来源：https://stackoverflow.com/questions/2072126/serverdocument-root