require_once path/to/file.php vs file.php

Question

I'm having the following issue when including a file that includes another file:

// path: /ajax/request.php
require_once("../classes/obj/Car.php");


// path: /classes/obj/Car.php;
require_once("Vehicle.php"); // superclass,  this works
require_once("../exception/NoWheelException");  // this doesn't work when Car.php is require_once()'d from /ajax/request.php

the problem seems to be that if a file A requires a file B that requires files C and D, it only works if C and D are used without "../", or "./" previous to the file name, when using require_once().

Is there any workaround or any ideas to fix this?

Ah yes, this is one of those times that PHP can really waste your time. http://www.php.net/manual/en/function.include.php The first comment is a good one, recommending the manipulation of working directory: But Izkata's answer is the more commonly used way to handle this, and its nice. — BrianH, Nov 07 '13 at 17:14
thank you, I had already given up and wrote a non-beautiful path like require_once($_SERVER['DOCUMENT_ROOT'] . "path/to/file/file.php"); — Christopher Francisco, Nov 07 '13 at 23:08

score 3 · Accepted Answer · edited May 23 '17 at 12:29

3

Use __FILE__ so you know where it's being included from:

require_once(dirname(__FILE__) . '/../exception/NoWheelException');

Where:

__FILE__ == "/classes/obj/Car.php";
dirname(__FILE__) == "/classes/obj";

Also, a note I didn't know - if your version of PHP is new enough, __DIR__ appears to be equivalent to dirname(__FILE__)

More info on __FILE__ and other magic constants here

edited May 23 '17 at 12:29

Community

1
1

answered Nov 07 '13 at 17:09

Izkata

8,961
2
40
50

require_once path/to/file.php vs file.php

1 Answers1