What is the scope of imports in PHP?

Question

I have three files at my server:

foo.php
assets/bar.php
assets/qux.php

foo.php includes bar.php, and bar.php includes qux.php. The code of foo.php is shown below:

<?php
    include_once("assets/bar.php");
?>

How should bar.php include qux.php? Should it use include("qux.php") or include("assets/qux.php")?

Asking is one way of getting the answer, but trying some experimenting (add some echo statements and what not) would likely be a better learning experience. — ernie, Jul 30 '13 at 15:46
@Gordon The "duplicate" doesn't talk about the paths at all. — JJJ, Jul 30 '13 at 15:51
It's pretty much explained in the PHP Manual: Files are included based on the file path given or, if none is given, the include_path specified. If the file isn't found in the include_path, include will finally check in the calling script's own directory and the current working directory before failing. If a path is defined — whether absolute (starting with a drive letter or \ on Windows, or / on Unix/Linux systems) or relative to the current directory (starting with . or ..) — the include_path will be ignored altogether. See http://php.net/manual/en/function.include.php — Gordon, Jul 30 '13 at 15:52
@Juhana I have tried both, but they both don't work. I wanted to be sure I was using the right one before I spend my time at (unnecessary) debugging. — FalconC, Jul 30 '13 at 15:54
@Juhana it's good enough for me since it references the PHP manual which the OP doesn't mention at all to have consulted prior to asking. But anyway, I'll reopen it. — Gordon, Jul 30 '13 at 15:56

score 2 · Answer 1 · answered Jul 30 '13 at 15:47

2

If they are in the same directory, then it is simply:

include("qux.php")

answered Jul 30 '13 at 15:47

Paddyd

score 2 · Answer 2 · answered Jul 30 '13 at 15:47

2

Assuming you haven't modified your includes path, include_once('qux.php') should work fine.

answered Jul 30 '13 at 15:47

ponysmith

score 0 · Accepted Answer · edited May 23 '17 at 10:31

It actually should use include("assets/qux.php"). The path to included files is dynamic; it depends in this case on foo.php.

If you are going to include bar.php from multiple directories, it is probably better to use absolute paths.

So, there are two ways to "chain-include" files in PHP:

Way #1 (Dynamic relative path)

include("assets/qux.php");

$ROOT = realpath($_SERVER["DOCUMENT_ROOT"]);
include("$ROOT/assets/qux.php");