Method doExecute

/**
 * Internal function to execute the command.
 *
 * @param   InputInterface   $input   The input to inject into the command.
 * @param   OutputInterface  $output  The output to inject into the command.
 *
 * @return  integer  The command exit code
 *
 * @since   4.0.0
 * @throws \Exception
 */
public function doExecute(InputInterface $input, OutputInterface $output) : int
{
    $this->configureIO($input, $output);
    $this->progressBar->setMessage("Starting up ...");
    $this->progressBar->start();
    $model = $this->getUpdateModel();
    $this->setUpdateInfo($model->getUpdateInformation());
    $this->progressBar->advance();
    $this->progressBar->setMessage('Running checks ...');
    if (!$this->updateInfo['hasUpdate']) {
        $this->progressBar->finish();
        $this->ioStyle->note('You already have the latest Joomla! version. ' . $this->updateInfo['latest']);
        return self::ERR_CHECKS_FAILED;
    }
    $this->progressBar->advance();
    $this->progressBar->setMessage('Starting Joomla! update ...');
    if ($this->updateJoomlaCore($model)) {
        $this->progressBar->finish();
        $this->ioStyle->success('Joomla core updated successfully!');
        return self::UPDATE_SUCCESSFUL;
    }
    $this->progressBar->finish();
    $this->ioStyle->error('Update cannot be performed.');
    return self::ERR_UPDATE_FAILED;
}