Wrong path using require_once

问题:

I have a problem tring to use require_once. I am specifying a wrong path and I can't find a solution.

I have a file named header.php that includes two files by using require_once: functions.php and navigation.php. This part is working fine. The problem appears when I try to include header.php in a file named view.php located in a different directory.

here is the arborescence:

C:\wamp\www\1.1\plugins\docreader\php\view.php
C:\wamp\www\1.1\theme\dark-blue\templates\files\header.inc.php
C:\wamp\www\1.1\theme\dark-blue\templates\files\functions.inc.php
C:\wamp\www\1.1\theme\dark-blue\templates\files\navigation.inc.php

I tried a lot of different paths but without any success.

Do someone have a clue please ?

回答1:

Read about (and use) the magic constant __DIR__ and function dirname() to generate the path of the included file starting from the path of the includer.

For example, if in plugins\docreader\php\view.php you want to include theme\dark-blue\templates\files\functions.inc.php then use something like this:

// Use this in 'plugins\docreader\php\view.php'
include dirname(dirname(dirname(__DIR__))).
        '/theme/dark-blue/templates/files/functions.inc.php';

__DIR__ is a magic constant that evaluates to the directory that contains the file where it is used. In C:\wamp\www\1.1\plugins\docreader\php\view.php, the value of __DIR__ is 'C:\wamp\www\1.1\plugins\docreader\php'.

The function dirname() returns the parent directory of the provided path. Kind of .., only better. Using it three times reduces the value passed as argument (the value of __DIR__ explained above) to 'C:\wamp\www\1.1'. Everything is straight forward from there: add the relative path to the desired file ('/theme/dark-blue/templates/files/functions.inc.php') and forget about inclusion problems.

回答2:

You need to make your file paths absolute rather than relative. A useful super global for achieving this is $_SERVER['DOCUMENT_ROOT'] which will evaluate to your web server file root.