yii\console\controllers\MessageController::saveMessagesToPOT PHP Method

    protected function saveMessagesToPOT($messages, $dirName, $catalog)
    {
        $file = str_replace("\\", '/', "{$dirName}/{$catalog}.pot");
        FileHelper::createDirectory(dirname($file));
        $this->stdout("Saving messages to {$file}...\n");
        $poFile = new GettextPoFile();
        $merged = [];
        $hasSomethingToWrite = false;
        foreach ($messages as $category => $msgs) {
            $msgs = array_values(array_unique($msgs));
            sort($msgs);
            foreach ($msgs as $message) {
                $merged[$category . chr(4) . $message] = '';
            }
            $this->stdout("Category \"{$category}\" merged.\n");
            $hasSomethingToWrite = true;
        }
        if ($hasSomethingToWrite) {
            ksort($merged);
            $poFile->save($file, $merged);
            $this->stdout("Translation saved.\n", Console::FG_GREEN);
        } else {
            $this->stdout("Nothing to save.\n", Console::FG_GREEN);
        }
    }