Require all files in a folder

Probably only by doing something like this:

$files = glob($dir . '/*.php');

foreach ($files as $file) {
    require($file);   
}

It might be more efficient to use opendir() and readdir() than glob().

No short way of doing it, you'll need to implement it in PHP. Something like this should suffice:

foreach (scandir(dirname(__FILE__)) as $filename) {
    $path = dirname(__FILE__) . '/' . $filename;
    if (is_file($path)) {
        require $path;
    }
}

There is no easy way, as in Apache, where you can just Include /path/to/dir, and all the files get included.

A possible way is to use the RecursiveDirectoryIterator from the SPL:

function includeDir($path) {
    $dir      = new RecursiveDirectoryIterator($path);
    $iterator = new RecursiveIteratorIterator($dir);
    foreach ($iterator as $file) {
        $fname = $file->getFilename();
        if (preg_match('%\.php$%', $fname)) {
            include($file->getPathname());
        }
    }
}

This will pull all the .php ending files from $path, no matter how deep they are in the structure.