Shows us all files and catalogues in directory except "." and "..".

<?php

foreach (new DirectoryIterator('../moodle') as $fileInfo) {
    if($fileInfo->isDot()) continue;
    echo $fileInfo->getFilename() . "<br>\n";
}

?>

DirectoryIterator::getBasename() has been also been available since 5.2.2, according to the changelog (not documented yet).  It takes a parameter $suffix, and is useful if, for instance, you use a naming convention for your files (e.g. ClassName.php).  

The following code uses this to add recursively All*Tests.php in any subdirectory off of tests/, basically, suites of suites.

<?php
// PHPUnit boilerplate code goes here

class AllTests {
    public static function main() {
        $parameters = array('verbose' => true);
        PHPUnit_TextUI_TestRunner::run(self::suite(), $parameters);
    }

    public static function suite() {
        $suite = new PHPUnit_Framework_TestSuite('AllMyTests'); // this must be something different than the class name, per PHPUnit
        $it = new AllTestsFilterIterator(
                  new RecursiveIteratorIterator(
                      new RecursiveDirectoryIterator(dirname(__FILE__) . '/tests')));

        for ($it->rewind(); $it->valid(); $it->next()) {
            require_once($it->current());
            $className = $it->current()->getBasename('.php');
            $suite->addTest($className::suite());
        }

        return $suite;
    }
}
?>

Also, the AllTestsFilterIterator above extends FilterIterator, and contains one method, accept():

<?php
class AllTestsFilterIterator extends FilterIterator {
    public function accept() {
        if (preg_match('/All.*Tests\.php/', $this->current())) {
            return true;
        } else {
            return false;
        }
    }
}
?>

Beware of the behavior when using FilesystemIterator::UNIX_PATHS, it's not applied as you might expect.

I guess this flag is added especially for use on windows.
However, the path you construct the RecursiveDirectoryIterator or FilesystemIterator with will not be available as a unix path.
I can't say this is a bug, since most methods are just purely inherited from DirectoryIterator.

In my test, I'd expected a complete unix path. Unfortunately... not quite as expected:

<?php
         // say $folder = C:\projects\lang

        $flags = FilesystemIterator::KEY_AS_PATHNAME | FilesystemIterator::CURRENT_AS_FILEINFO | FilesystemIterator::SKIP_DOTS | FilesystemIterator::UNIX_PATHS;
        $d_iterator = new RecursiveDirectoryIterator($folder, $flags);

        echo $d_iterator->getPath();

?>

expected result: /projects/lang (or C:/projects/lang)
actual result: C:\projects\lang

DirectoryIterator is just an lightweight SplFileInfo iterator and its methods operate on whatever item the internal cursor points to. In other words:

<?php
$iterator = new DirectoryIterator('C:\\');
echo $iterator->getPathname();
?>

... will NOT print "C:\" but the path of the first file or subdirectory retrieved, e.g. "C:\$Recycle.Bin".