addArgument('env', InputArgument::OPTIONAL, 'The environment variable to show, if not set, all will be shown'); } public function initialize(InputInterface $input, OutputInterface $output): void { $this->no_motd = true; parent::initialize($input, $output); } public function handle(): int { $env = $this->getArgument('env'); if (($val = getenv($env)) === false) { $this->output->writeln("Environment variable '{$env}' is not set."); return static::FAILURE; } if (is_array($val)) { foreach ($val as $k => $v) { $this->output->writeln("{$k}={$v}"); } return static::SUCCESS; } $this->output->writeln("{$val}"); return static::SUCCESS; } }