Make the wpmembers upload directory a random hash value

/**
 * Use a random hash as the plugin's general upload directory name.
 * 
 * This example uses a random string length of 32 chars, but you
 * can change the value to whatever suits (longer or shorter).
 */
add_filter( 'wpmem_settings', function( $settings ) {
    
    // How long of a hash?
    $hash_len = 32;
    
    // Check if we already created a hash.
    $hash = get_option( 'wpmem_file_dir_hash' );
    if ( ! $hash ) {
        // If there is no existing hash, create with wp_generate_password().
        $hash = wp_generate_password( $hash_len, false, false );
        update_option( 'wpmem_file_dir_hash', $hash );
    }
    
    /*
     * What format of the main directory is desired?
     * This example makes it "userfiles_2NUMkyuWC08n09".
     * The directory does not need to include "wpmembers" in the name.
     * It can be whatever name is desired. Or, it can be just the
     * hash value as the name.  It's up to the site admin.
     */
    $settings['upload_base'] = "userfiles_" . $hash;
    
    return $settings;
});