HelloWorld

#!/usr/bin/env php
<?php
require __DIR__.'/vendor/autoload.php';

use Symfony\Component\Console\Application;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;

(new Application('Hello World', '1.0.0'))
      ->register('greet')

      ->addArgument('name', InputArgument::OPTIONAL, 'Name of the person')

      ->addOption('say', null, InputOption::VALUE_REQUIRED, 'Custom greeting')

      ->setCode(function (InputInterface $input, OutputInterface $output) {
              
        $name = $input->getArgument('name');
        $greeting = $input->getOption('say');

        if (!empty($name) && !empty($greeting)) {
            return $output->writeln("<info>$greeting $name!</info>");
        } else if (!empty($name)) {
            return $output->writeln("<info>Hello $name!</info>");
        } else if (!empty($greeting)) {
            return $output->writeln("<info>$greeting World!</info>");
        } else {
            return $output->writeln("<info>Hello World!</info>");
        }
      })
      ->getApplication()
      ->run();