How to create custom Drush command in Drupal

In this tutorial se are going learn how to create custom Drush command in drupal. For that we need to create a custom module. The file structure will be like below

drush_command_example
   Commands
      CustomCommands.php
   drush_command_example.info
  drush.services.yml

1. drush_command_example.info file

name: Drush Command Example
description: This is our custom drush command.
core: 8.x
core_version_requirement: ^8 || ^9
type: module
package: ttn

2. drush.services.yml file.

services:
  drush_command_example.commands:
    class: \Drupal\drush_command_example\Commands\CustomCommands
    tags:
      - { name: drush.command }

3. CustomCommands.php file.

<?php
namespace Drupal\drush_command_example\Commands;
use Drush\Commands\DrushCommands;


/**
 * Drush command file.
 */
class CustomCommands extends DrushCommands {

  /**
   * A custom Drush command to displays the given text.
   * 
   * @command drush-command-example:print-me
   * @param $text Argument with text to be printed
   * @option uppercase Uppercase the text
   * @aliases ttndrush,tthndrush-print-me
   */
  public function printMe($text = 'Hello world!', $options = ['uppercase' => FALSE]) {
    if ($options['uppercase']) {
      $text = strtoupper($text);
    }
    $this->output()->writeln($text);
  }
} Enable module or if you created drush command in existing module than please clear cache. you can see custom drush command in list using

drush list

We can use our newly created drush command as below.

drush ttndrush --help 
drush ttndrush "hello from to the new" 
drush ttndrush "hello from to the new" --uppercase 
drush ttndrush-print-me "hello from to the new" 
drush ttndrush-print-me "hello from to the new" --uppercase