If you have files in different directories that include a php file which also includes other file, a problem can be the patch that can changes when the file is included from different level of directories.
For example, in this files and folders structure:
/
- dir1/
  - dir1_2/
      level_2.php

  level_1.php

config.php
index.php
- "level_1.php" (which is in "dir1/") include "config.php".
- "level_2.php" (which is in "dir1_2/") include "level_1.php".
- "index.php" (in root "/") include "level_1.php".

As you can notice, "level_1.php" is included from root (in "index") and from "dir1_2/" (in "level_2").
If in 'level_1.php' we include "config.php" using:
include('../config.php');
This code will not work when "level_1.php" is included in the other files.

The problem is, how to include "config.php" in "level_1.php" so this file can be accessed from anywhere?
I tried with absolute /full server path, using:   dirname(__FILE__) (or: __DIR__ ), but didn't work in Windows.
After searching on the net to find a proper solution to this problem, I found the following code, that gets the relative path to Web Site Root directory ("www/", "public_html/", "httpdocs/"):
$current_path = pathinfo($_SERVER['SCRIPT_NAME'], PATHINFO_DIRNAME);
$current_host = pathinfo($_SERVER['REMOTE_ADDR'], PATHINFO_BASENAME);
$the_depth = substr_count( $current_path , '/');

// Set path to root for includes to access from anywhere
if($current_host == '127.0.0.1') $pathtoroot = str_repeat('../' , $the_depth-1);
else $pathtoroot = str_repeat ('../' , $the_depth);

echo $pathtoroot;

I put this code into a function that returns the relative path to Web Site Root directory from any current folder, and the problem was solved using this function to include "config.php" in "level_1.php", that can be accessed from anywhere.
// returns the relative path from current folder to Web Site Root directory
function getRootPath() {
  $current_path = pathinfo($_SERVER['SCRIPT_NAME'], PATHINFO_DIRNAME);
  $current_host = pathinfo($_SERVER['REMOTE_ADDR'], PATHINFO_BASENAME);
  $the_depth = substr_count( $current_path , '/');

  // Set path to root for includes to access from anywhere
  if($current_host == '127.0.0.1') $pathtoroot = str_repeat('../' , $the_depth-1);
  else $pathtoroot = str_repeat ('../' , $the_depth);

  return $pathtoroot;
}

// include file located in root
include(getRootPath(). 'config.php');

Daily Test with Code Example

HTML
CSS
JavaScript
PHP-MySQL
Which tag defines the clickable areas inside the image map?
<map> <img> <area>
<img src="image.jpg" usemap="#map1">
<map name="map1">
  <area shape="rect" coords="9, 120, 56, 149" href="#">
  <area shape="rect" coords="100, 200, 156, 249" href="#">
</map>
Which CSS property defines what is done if the content in a box is too big for its defined space?
display overflow position
#id {
  overflow: auto;
}
Click on the event which is triggered when the mouse is positioned over an object.
onclick onmouseover onmouseout
document.getElementById("id").onmouseover = function(){
  document.write("Have Good Life");
}
Indicate the PHP variable that contains data added in URL address after the "?" character.
$_SESSION $_GET $_POST
if(isset($_GET["id"])) {
  echo $_GET["id"];
}
Get Relative Path to Website Root for Includes to Access from Anywhere

Last accessed pages

  1. Get visitor IP in PHP (842)
  2. PHP PDO - exec (INSERT, UPDATE, DELETE) MySQL (43359)
  3. Common PHP Errors and Solutions (6866)
  4. SSEP - Site Search Engine PHP-Ajax (7095)
  5. PHP Method Chaining (1706)

Popular pages this month

  1. Insert, Select and Update NULL value in MySQL (697)
  2. Read Excel file data in PHP - PhpExcelReader (625)
  3. PhpSpreadsheet - Read, Write Excel and LibreOffice Calc files (394)
  4. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (347)
  5. PHP getElementById and getElementsByTagName (311)