Another directory listing function that uses a regular expression as a filter.

get_dlist.php

/**
 * Returns a list of all file nodes for a given path.
 *
 * @param path    The path for which to build a list of file node entries.
 * @param pattern Optional filter pattern to test each node name against.
 *                The default pattern prevents returning hidden node entries.
 * @return        A list of node entries in the given path.
 */
function get_dlist( $path, $pattern = '/^[^.]/' ) {
    $nodes = [];
    $dh = opendir( $path );
    if( $dh ) {
        while( ( $node = readdir( $dh ) ) !== false ) {
            if( preg_match( $pattern, $node ) ) {
                $nodes[] = $node;
            }
        }
        closedir( $dh );
        sort( $nodes );
    }
    return $nodes;
}