A 'Hello World' for WP CLI

twc_cli.php

<?php
/*
Plugin Name: 10web Hello World
Plugin URI: https://10web.io/
Description: Teaching the basics of WP-CLI
Author: Vanush 10web
Version: 1.0.0
Author URI: https://10web.io/
*/

/**
* My custom command to print greeting.
*/
class TWC_CLI {

	/**
	 * Returns 'Hello World'
	 *
	 * @since  0.0.1
	 * @author Vanush 10web
	 */
	public function hello_world() {
		WP_CLI::line( 'Hello World!' );
	}

}

/**
 * Registers our command when cli get's initialized.
 *
 * @since  1.0.0
 * @author Vanush 10web
 */
function twc_cli_register_commands() {
	WP_CLI::add_command( 'twc', 'TWC_CLI' );
}

add_action( 'cli_init', 'twc_cli_register_commands' );