Add WP CLI Command

if (class_exists('WP_CLI')) {
    WP_CLI::add_command('wpm_pipm_import', 'wpm_pipm_import', $args = array());
}

/**
 * @param $message
 */
function wpm_log($message)
{
    if (class_exists('WP_CLI')) {
        WP_CLI::log(date('H:i:s') . ' ' . $message);
    } else {
        echo date('H:i:s') . ' ' . $message . PHP_EOL;
    }
}

wpm_log('Getting catalog');
// ...
wpm_log('Catalog grabbed');

$progress = WP_CLI\Utils\make_progress_bar('Creating top categories', $categories_count);
foreach (...) {
    $progress->tick();
}