Helloworld.script

<?php

//
// This example demonstrates how to write a drush
// script.  These scripts are run with the php-script command.
//
use Drush\Drush;

$this->output()->writeln("Hello world!");
$this->output()->writeln("The extra options/arguments to this command were:");
$this->output()->writeln(print_r($extra, true));



//
// We can check which site was bootstrapped via
// the '@self' alias, which is defined only if
// there is a bootstrapped site.
//
$self = Drush::aliasManager()->getSelf();;
if (!$self->hasRoot()) {
  $this->output()->writeln('No bootstrapped site.');
}
else {
  $this->output()->writeln('The following site is bootstrapped:');
  $this->output()->writeln(print_r($self->legacyRecord(), true));
}