server/core/command/config/app/getconfig.php

<?php
/**
 * @author Joas Schilling <nickvergessen@owncloud.com>
 *
 * @copyright Copyright (c) 2015, ownCloud, Inc.
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\Core\Command\Config\App;

use OC\Core\Command\Base;
use OCP\IConfig;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;

class GetConfig extends Base {
	/** * @var IConfig */
	protected $config;

	/**
	 * @param IConfig $config
	 */
	public function __construct(IConfig $config) {
		parent::__construct();
		$this->config = $config;
	}

	protected function configure() {
		parent::configure();

		$this
			->setName('config:app:get')
			->setDescription('Get an app config value')
			->addArgument(
				'app',
				InputArgument::REQUIRED,
				'Name of the app'
			)
			->addArgument(
				'name',
				InputArgument::REQUIRED,
				'Name of the config to get'
			)
			->addOption(
				'default-value',
				null,
				InputOption::VALUE_OPTIONAL,
				'If no default value is set and the config does not exist, the command will exit with 1'
			)
		;
	}

	/**
	 * Executes the current command.
	 *
	 * @param InputInterface  $input  An InputInterface instance
	 * @param OutputInterface $output An OutputInterface instance
	 * @return null|int null or 0 if everything went fine, or an error code
	 */
	protected function execute(InputInterface $input, OutputInterface $output) {
		$appName = $input->getArgument('app');
		$configName = $input->getArgument('name');
		$defaultValue = $input->getOption('default-value');

		if (!in_array($configName, $this->config->getAppKeys($appName)) && !$input->hasParameterOption('--default-value')) {
			return 1;
		}

		if (!in_array($configName, $this->config->getAppKeys($appName))) {
			$configValue = $defaultValue;
		} else {
			$configValue = $this->config->getAppValue($appName, $configName);
		}

		$this->writeMixedInOutputFormat($input, $output, $configValue);
		return 0;
	}
}