Calling a Function in Functions.php from an external PHP script

Question

Preamble

I tried to make sure this question was not asked before. I'm new to using StackExchange so I may have failed in doing so. I don't mind rebukes; thick skin and I learn fast :)

THE PROBLEM

I wrote a function and placed in my theme's functions.php

function serverConnect() {

$serverAccess = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);

if (!$serverAccess) {
    die("Access Denied");
}

return $serverAccess; 
}

The idea was to be able to have the ability to log into the DB abstracted to a function so whenever my unconventional theme needed it I could log in and do what needed to be done.

As I built more functions, I felt it would be advantageous to break off some functionality into external php files. This script is called when a form is posted in the admin cp.

In theme-root/scripts/hypothetical-theme-function.php:

$switch = mysql_select_db( 'differentDB', serverConnent());

The problem here is that hypothetical-theme-function.php has no access to functions.php to be able to call serverConnect();

I've tried include(/path/to/functions.php), include_once(/path/to/functions.php), require(/path/to/functions.php) and require_once(/path/to/functions.php). The errors I get with the once commands is:

Fatal error: Call to undefined function serverConnent() ...

The problem I get with include or require is:

Fatal error: Cannot redeclare serverConnect() ...

THE QUESTION

How do I call any function in Functions.php from an external php script?

Answer 1

You're much better off with using a (mu-)plugin. Just add a folder named mu-plugins in your wp-content directory and place your files there. Then add a plugin header comment to it:

<?php
/**
 * Plugin Name: Some Name
 * Plugin URI: http://example.com
 * Description: Loads something
 * Version: 0.1
 * Author: Akamaozu
 * Author URI: http://example.com
 * License: GNU GPL 2 <https://gist.github.com/1365159>
 */
// deny direct file access if WP not loaded
! defined( 'ABSPATH' ) AND exit;

// define your functions here
function foo()
{
    print '<h1>'.__FILE__.' loaded successfully!</h1>';
}
add_action( 'shutdown', 'foo' );

Answer 2

From within your external script try calling wp-load.php - example;

require( '../your-path-to-your-wp-base-directory/wp-load.php' );

See how you fair then...