drushrc.php

<?php

// Load a drushrc.php file from the 'drush' folder at the root of the current
// git repository.
if ($repo_root = _drushrc_find_repo_root()) {
  drush_set_context('DRUSH_REPO_ROOT', $repo_root);
  if (is_dir($repo_root . '/drush')) {
    if (is_file($repo_root . '/drush/drushrc.php')) {
      $options['config'] = $repo_root . '/drush/drushrc.php';
    }
    if (is_dir($repo_root . '/drush/commands')) {
      $options['include'] = $repo_root . '/drush/commands';
    }
    if (is_dir($repo_root . '/drush/aliases')) {
      $options['alias-path'] = $repo_root . '/drush/aliases';
    }
  }
}

/**
 * Attempt to find the root directory of a Git clone.
 *
 * @param string $directory
 *   The directory that may be inside a Git checkout.
 *
 * @return string|bool
 *   The Git root directory if found, or FALSE otherwise.
 */
function _drushrc_find_repo_root($directory = NULL) {
  if (!isset($directory)) {
    $directory = _drushrc_find_drupal_root();
  }
  if (!is_dir($directory)) {
    return FALSE;
  }
  $success = drush_shell_cd_and_exec($directory, 'git rev-parse --show-toplevel 2> ' . drush_bit_bucket());
  if ($success) {
    $output = drush_shell_exec_output();
    return $output[0];
  }
  return FALSE;
}

/**
 * Attempt to find the current Drupal root directory.
 */
function _drushrc_find_drupal_root() {
  if ($root = drush_get_option('root')) {
    return $root;
  }
  
  // Fallback to the current directory.
  return drush_cwd();
}