PHP: require doesn't work as it should

Question

I have a directory root:

index.php
includes/
    template.php
    testfile.php
    phpFiles/
        processInput.php
        testfile.php

index.php:

require_once("includes/template.php");

template.php:

require_once("includes/phpFiles/processInput.php")

processInput.php:

require_once("testfile.php")
require_once("../testfile.php")

This code will work when you run index.php, of course it will not work when you run template.php.

As you can see, index.php includes template.php like normal. But in template.php, you have to include like if you are in the directory that index.php is in. But then, in processInput.php, you include as if you are in the directory that processInput.php is in.

Why is this happening, and how can I fix it so that the include path is always the directory of the file that the require is done in? The second included file have the same include path as the requested file, but the next one does not.

Thanks for your help!

EDIT: The strange thing is that I've included classes in a class folder. And it included other files as it is supposed to, even though the paths are relative. WHY does this happen, and how can I fix it?

VERY IMPORTANT EDIT: I just realized that all this is because in my example, the inclusion in includes/phpFiles/processInput.php includes a file in the same directory: require_once("file in same dir.php"); This is the reason. If you are including a file with out specifying anything more than the filename, the include_path is actually the dir where the file the require is written in is in. Can anyone confirm this?

Answer 1

Use an absolute path.

require_once($_SERVER['DOCUMENT_ROOT']."/includes/phpFiles/processInput.php");

Use a similar form for all your required files and they will work no matter where you are.

Answer 2

You can do this in a few ways, amongst others:

1. Use set_include_path to control the directories from where to perform require() calls.

2. Define a common absolute base path in a constant that you define in index.php and use that in every require() statement (e.g. require(BASEPATH . '/includes/template.php')).

3. Use relative paths everywhere and leverage dirname(__FILE__) or __DIR__ to turn them into absolute paths. For instance: require(__DIR__ . '/phpFiles/processInput.php');

By default, the current working directory is used in the include path; you can verify this by inspecting the output of get_include_path(). However, this is not relative to where the include() is made from; it's relative to the main executing script.