Building a CLI Command with Symfony Console

A Symfony Console Command encapsulates one operation with configured arguments and execute() logic.

What It Does and When to Use It

Inspect an individual command and its arguments. CLI commands consume arguments, communicate via STDOUT/STDERR, and return process exit codes; web handlers use HTTP status codes.

Requirements, Inputs and Expected Behavior

Confirm the runtime, extension, environment variables, and permissions before running the examples in production. Return Command::SUCCESS or FAILURE and validate destructive options before doing work.

Example 1: Basic Operation

Inspect an individual command and its arguments.

composer require symfony/console
php bin/console app:cleanup --help

Example 2: Behavior and Validation

Validate a command argument and return a stable exit code.

<?php
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
final class CleanupCommand extends Command {
    protected function configure(): void { $this->setName('app:cleanup')->addArgument('days',InputArgument::REQUIRED); }
    protected function execute(InputInterface $input,OutputInterface $output): int { $days=filter_var($input->getArgument('days'),FILTER_VALIDATE_INT); if ($days===false||$days<1) return Command::INVALID; $output->writeln('Cleaning older than '.$days.' days'); return Command::SUCCESS; }
}

Practical Example: Application Use

Register and execute the self-contained command with Symfony Console.

<?php
$application=new Symfony\Component\Console\Application('Maintenance');
$application->add(new CleanupCommand());
exit($application->run());

Important Behavior and Edge Cases

The second example highlights: Validate a command argument and return a stable exit code. The practical example adds: Register and execute the self-contained command with Symfony Console.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• A Symfony Console Command encapsulates one operation with configured arguments and execute() logic.
• Register and execute the self-contained command with Symfony Console.
• Avoid assuming $_SERVER has the same keys in both SAPIs.