PHP动态获取根目录绝对路径

Question

I'm a newbie of php.

I would like to create a php config file where to set the absolute path of my project directory structure. My config file is located in 'private/class' directory and it will be included in 'root' and private directory files.

Project directory structure is

class
img
photo
etc
private/class
private/photo
private/photo/thumb
private/etc

To get the absolute path where the file is located, I use magic php costants DIR ,

define('MAINPATH', __DIR__ );

this show

/var/www/projectname/private/class

and this variable remains the same if I include the config file in the index.php or private/index.php , etc.

Now I have the problem of finding the other path starting from the main one. Usually I use realpath, but in this case I do not think will go well. I tried in this way

define('PHOTOPATH', __DIR__ . '../photo');

define('PHOTOPATH', realpath ( __DIR__ . '../photo'));

these show

1 - /var/www/projectname/private/class../photo
2 - nothing

How could I do this? Thank you

Answer 1

You just need to append the PATH SEPARATOR ( / ) before appending the rest of the path.

define('PHOTOPATH', realpath ( __DIR__ . '/../photo'));
                                         ^
                                         |
                                         +- notice here the '/' is added

Answer 2

您可以使用$ _SERVER ['DOCUMENT_ROOT']。