Custom CLI commands Magento 2

Magento 2 enables your component to add commands to the default CLI

Magento has one command-line interface that performs both installation and configuration tasks: /bin/magento.

I am explaining here a way to add custom commands for your module.

1) Create a Command class, I have created a custom class
at app/code/DW/Interface/Console/OrderCron.php.

<?php
/**
 * @author DW
 * @copyright Copyright (c) 2019 DecryptWeb (https://www.decryptweb.com/)
 */
namespace DW\Interface\Console;

use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Symfony\Component\Console\Input\InputOption;
use DW\Interface\Cron\OrderUpdate;

/**
 * Class for OrderCron
 */
class OrderCron extends Command
{
    /**
     * @var string
     */
    const ST = 'st';
    const ET = 'et';

    /**
     * @var orderupdate
     */
    protected $orderUpdate;

    /**
     * OrderCron constructor.
     *
     * @param OrderUpdate $orderUpdate OrderUpdate
     * @param string|null $name        string
     */
    public function __construct(
        OrderUpdate $orderUpdate,
        string $name = null
    ) {
        $this->orderUpdate = $orderUpdate;
        parent::__construct($name);
    }

    /**
     * OrderCron Configure
     */
    protected function configure()
    {
        $options = [
            new InputOption(
                self::ST,
                null,
                InputOption::VALUE_OPTIONAL,
                'StartDate'
            ),
            new InputOption(
                self::ET,
                null,
                InputOption::VALUE_OPTIONAL,
                'EndDate'
            ),
        ];

        $this->setName('order:post:send');
        $this->setDescription('Send order to ERP);
        $this->setDefinition($options);

        parent::configure();
    }

    /**
     * @param InputInterface  $input  InputInterface
     * @param OutputInterface $output OutputInterface
     * @return int|void|null
     */
    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $this->orderUpdate->execute($input->getOption(self::ST), $input->getOption(self::ET)); //call custom function along with arguments
    }
}

2) Declare your Command class in Magento\Framework\Console\CommandList and configure the command name using dependency injection (app/code/DW/Interface/etc/di.xml)

<!-- Custom command -->
<type name="Magento\Framework\Console\CommandList">
<arguments>
    <argument name="commands" xsi:type="array">
        <item name="orderUpdateCron" xsi:type="object">DW\Interface\Console\OrderCron</item>
    </argument>
</arguments>
</type>

3) Clean the cache:

bin/magento cache:clean

4) Regenerate the code:

bin/magento setup:di:compile

As a result, the new command order:post:send that accepts multiple parameters is ready to use.

bin/magento order:post:send --st='2019-01-01' --et='2019-02-01'

Hope this is helpful