PHP include relative path

I have file /root/update/test.php. There's also a file, /root/connect.php; This file has a line

include "../config.php";

In /root/update/test.php. There's the code

set_include_path(".:/root");
include "connect.php";

When I run /root/update/test.php, it finds connect.php, but fails to find config.php, giving me

PHP Warning:  include(../config.php): failed to open stream: No such file or directory in /root/connect.php on line 2
PHP Warning:  include(): Failed opening '../config.php' for inclusion (include_path='.:/root')

This is confusing to me because the warnings make it seem like I'm doing everything correctly - the include path is /root, and it's looking for file ../config.php (/config.php), which exists. Can someone clear this up for me? Note that using absolute paths is not an option for me, due to deploying to a production server that I have no access to.

Ubuntu/Apache


Solution 1:

You could always include it using __DIR__:

include(dirname(__DIR__).'/config.php');

__DIR__ is a 'magical constant' and returns the directory of the current file without the trailing slash. It's actually an absolute path, you just have to concatenate the file name to __DIR__. In this case, as we need to ascend a directory we use PHP's dirname which ascends the file tree, and from here we can access config.php.

You could set the root path in this method too:

define('ROOT_PATH', dirname(__DIR__) . '/');

in test.php would set your root to be at the /root/ level.

include(ROOT_PATH.'config.php');

Should then work to include the config file from where you want.

Solution 2:

While I appreciate you believe absolute paths is not an option, it is a better option than relative paths and updating the PHP include path.

Use absolute paths with an constant you can set based on environment.

if (is_production()) {
    define('ROOT_PATH', '/some/production/path');
}
else {
    define('ROOT_PATH', '/root');
}

include ROOT_PATH . '/connect.php';

As commented, ROOT_PATH could also be derived from the current path, $_SERVER['DOCUMENT_ROOT'], etc.

Solution 3:

function relativepath($to){
    $a=explode("/",$_SERVER["PHP_SELF"] );
    $index= array_search("$to",$a);
    $str=""; 
    for ($i = 0; $i < count($a)-$index-2; $i++) {
        $str.= "../";
    }
    return $str;
    }

Here is the best solution i made about that, you just need to specify at which level you want to stop, but the problem is that you have to use this folder name one time.