drush.php

<?php

use Drush\Drush;
use Drush\Config\Environment;
use Drush\Preflight\Preflight;
use Drush\Runtime\Runtime;
use Webmozart\PathUtil\Path;

/**
 * This script runs Drush.
 *
 * Responsibilities of this script:
 *   - Locate and include the Composer autoload file for Drush.
 *   - Set up the environment (record user home directory, cwd, etc.).
 *   - Call the Preflight object to do all necessary setup and execution.
 *   - Exit with status code returned
 *
 * It is our goal to put all $_SERVER access and other constructs that are
 * difficult to test in this script to reduce the burden on the unit tests.
 * This script will only be tested via the functional tests.
 *
 * The Drush bootstrap goes through the following steps:
 *   - (ArgsPreprocessor) Preprocess the commandline arguments, considering only:
 *     - The named alias `@sitealias` (removed from arguments if present)
 *     - The --root option (read and retained)
 *     - The --config option (read and retained)
 *     - The --alias-path option (read and retained)
 *   - Load the Drush configuration and alias files from the standard
 *     global locations (including --config and --alias-path)
 *   - Determine the local Drupal site targeted, if any
 *   - Include the Composer autoload for Drupal (if different)
 *   - Extend configuration and alias files to include files in target Drupal site.
 *   - Create the Robo DI container and Symfony Application et. al.
 *   - Run the Symfony Application
 *     - Predispatch: call a remote Drush command if applicable
 *     - Bootstrap Drupal via @bootstrap command hook
 *     - Run commands and command hooks via annotated commands library
 *     - Catch 'command not found' exception, bootstrap Drupal and run again
 *   - Return status code
 */

// We use PWD if available because getcwd() resolves symlinks, which
// could take us outside of the Drupal root, making it impossible to find.
$cwd = empty($_SERVER['PWD']) ? getcwd() : $_SERVER['PWD'];

// Set up autoloader
$loader = false;
if (file_exists($autoloadFile = __DIR__ . '/vendor/autoload.php')
    || file_exists($autoloadFile = __DIR__ . '/../autoload.php')
    || file_exists($autoloadFile = __DIR__ . '/../../autoload.php')
) {
    $loader = include_once($autoloadFile);
} else {
    throw new \Exception("Could not locate autoload.php. cwd is $cwd; __DIR__ is " . __DIR__);
}

// Set up environment
$environment = new Environment(Path::getHomeDirectory(), $cwd, $autoloadFile);
$environment->setConfigFileVariant(Drush::getMajorVersion());
$environment->setLoader($loader);
$environment->applyEnvironment();

// Preflight and run
$preflight = new Preflight($environment);
$runtime = new Runtime($preflight);
$status_code = $runtime->run($_SERVER['argv']);

exit($status_code);