Relative path problems with PHP

In PHP require,include a file, mostly with a relative path, is a very headache problem.

For example:

<web> (website root directory)

├<a> folder

││

│└1.php

├<b> folder

││

│└2.php

└index.php

Issue: In 1.php through the include (".. /b/2.php ") to introduce 2.php files under the B directory;

Introduce the 1.php file under the A directory by include ("a/1.php") in index.php;

Run out of course there will be problems, not found. /b/2.php file.

Keep in mind a principle that all include statements are converted to include paths that contain file paths as a base, it is recommended to use a basic path as a reference for all paths, such as __file__ or $_server[' Document_root ']

__file__: (Suitable for all situations)

Configure the site root directory in the config file
Define ("Web_root", DirName (__file__));
Config file to the root of the Web site,
Other files contain configuration files,
When you include other files, you can locate them according to Web_root.
Require_once (Web_root. "/a.php");

$_server[' Document_root ', suitable for non-virtual host (Alias) situations

PHP code

<?php  if (!defined ("Wetsite_base_dir"))  define ("Wetsite_base_dir", $_server[' Document_root ']. ' /clare/');      Require_once (wetsite_base_dir. ' includes/global.inc.php ');  ? >

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