PHP read sub-directories and loop through files how to?

Question

I need to create a loop through all files in subdirectories. Can you please help me struct my code like this:

$main = "MainDirectory";
loop through sub-directories {
    loop through filels in each sub-directory {
        do something with each file
    }
};

Answer 1

Use RecursiveDirectoryIterator in conjunction with RecursiveIteratorIterator.

$di = new RecursiveDirectoryIterator('path/to/directory');
foreach (new RecursiveIteratorIterator($di) as $filename => $file) {
    echo $filename . ' - ' . $file->getSize() . ' bytes <br/>';
}