Autoload Example

autoload.php

<?php

define('CLASS_DIR', __DIR__ . DIRECTORY_SEPARATOR . 'src' . DIRECTORY_SEPARATOR);
set_include_path(get_include_path().PATH_SEPARATOR.CLASS_DIR);
spl_autoload_register();

autoload_linux.php

<?php

define('CLASS_DIR', __DIR__ . DIRECTORY_SEPARATOR . 'src' . DIRECTORY_SEPARATOR);
set_include_path(get_include_path().PATH_SEPARATOR.CLASS_DIR);
spl_autoload_register(function($className) {
    $path = str_replace('\\', DIRECTORY_SEPARATOR, $className);
    $file = CLASS_DIR . $path . '.php';
    if (is_file($file)) {
        require_once($file);
    } else {
        throw new \ErrorException("Could not load class {$className}. File not found: {$file}");
        die();
    }
});