A function to get a list of files from the current directory and all subdirectories, returned in an array.

getFileList.php

function getFilesList ($scanDirectory) {
    /** Create empty arrays for the files to scan and directories to evaluate */
    $_filesToBeScanned = array();
    $_directoriesLeftToEvaluate = array();

    /** Add the first directoy on to the evaluation queue */
    array_push($_directoriesLeftToEvaluate, $scanDirectory);

    while (count($_directoriesLeftToEvaluate) !== 0) {
        /** Grab the last directory */
        $thisIterationsDirectory = array_pop($_directoriesLeftToEvaluate);

        /** Operate on every entity in the directory */
        foreach (glob($thisIterationsDirectory . "/*") as $entity) {
            if (is_dir($entity)) {
                /** If the entity is a directory then add it to the evaluation list */
                array_push($_directoriesLeftToEvaluate, $entity);
            } else if (is_file($entity)) {
                /** If the entity is a file then add it to the list of files to be scanned */
                array_push($_filesToBeScanned, $entity);
            }
        }
    }

    return $_filesToBeScanned;
}