Club Drupal

<?php

/**

* @file

* API functions for installing modules and themes.

*/

/**

 * Indicates that a module has not been installed yet.

 */

define('SCHEMA_UNINSTALLED', -1);

/**

 * Indicates that a module has been installed.

 */

define('SCHEMA_INSTALLED', 0);

/**

 * Requirement severity -- Informational message only.

 */

define('REQUIREMENT_INFO', -1);

/**

 * Requirement severity -- Requirement successfully met.

 */

define('REQUIREMENT_OK', 0);

/**

 * Requirement severity -- Warning condition; proceed but flag warning.

 */

define('REQUIREMENT_WARNING', 1);

/**

 * Requirement severity -- Error condition; abort installation.

 */

define('REQUIREMENT_ERROR', 2);

/**

 * File permission check -- File exists.

 */

define('FILE_EXIST', 1);

/**

 * File permission check -- File is readable.

 */

define('FILE_READABLE', 2);

/**

 * File permission check -- File is writable.

 */

define('FILE_WRITABLE', 4);

/**

 * File permission check -- File is executable.

 */

define('FILE_EXECUTABLE', 8);

/**

 * File permission check -- File does not exist.

 */

define('FILE_NOT_EXIST', 16);

/**

 * File permission check -- File is not readable.

 */

define('FILE_NOT_READABLE', 32);

/**

 * File permission check -- File is not writable.

 */

define('FILE_NOT_WRITABLE', 64);

/**

 * File permission check -- File is not executable.

 */

define('FILE_NOT_EXECUTABLE', 128);

/**

 * Loads .install files for installed modules to initialize the update system.

 */

function drupal_load_updates() {

  foreach (drupal_get_installed_schema_version(NULL, FALSE, TRUE) as $module => $schema_version) {

    if ($schema_version > -1) {

      module_load_install($module);

    }

  }

}

/**

 * Returns an array of available schema versions for a module.

 *

 * @param $module

 *   A module name.

 * @return

 *   If the module has updates, an array of available updates sorted by version.

 *   Otherwise, FALSE.

 */

function drupal_get_schema_versions($module) {

  $updates = &drupal_static(__FUNCTION__, NULL);

  if (!isset($updates[$module])) {

    $updates = array();

    foreach (module_list() as $loaded_module) {

      $updates[$loaded_module] = array();

    }

    // Prepare regular expression to match all possible defined hook_update_N().

    $regexp = '/^(?P<module>.+)_update_(?P<version>\d+)$/';

    $functions = get_defined_functions();

    // Narrow this down to functions ending with an integer, since all

    // hook_update_N() functions end this way, and there are other

    // possible functions which match '_update_'. We use preg_grep() here

    // instead of foreaching through all defined functions, since the loop

    // through all PHP functions can take significant page execution time

    // and this function is called on every administrative page via

    // system_requirements().

    foreach (preg_grep('/_\d+$/', $functions['user']) as $function) {

      // If this function is a module update function, add it to the list of

      // module updates.

      if (preg_match($regexp, $function, $matches)) {

        $updates[$matches['module']][] = $matches['version'];

      }

    }

    // Ensure that updates are applied in numerical order.

    foreach ($updates as &$module_updates) {

      sort($module_updates, SORT_NUMERIC);

    }

  }

  return empty($updates[$module]) ? FALSE : $updates[$module];

}

/**

 * Returns the currently installed schema version for a module.

 *

 * @param $module

 *   A module name.

 * @param $reset

 *   Set to TRUE after modifying the system table.

 * @param $array

 *   Set to TRUE if you want to get information about all modules in the

 *   system.

 * @return

 *   The currently installed schema version, or SCHEMA_UNINSTALLED if the

 *   module is not installed.

 */

function drupal_get_installed_schema_version($module, $reset = FALSE, $array = FALSE) {

  static $versions = array();

  if ($reset) {

    $versions = array();

  }

  if (!$versions) {

    $versions = array();

    $result = db_query("SELECT name, schema_version FROM {system} WHERE type = :type", array(':type' => 'module'));

    foreach ($result as $row) {

      $versions[$row->name] = $row->schema_version;

    }

  }

  if ($array) {

    return $versions;

  }

  else {

    return isset($versions[$module]) ? $versions[$module] : SCHEMA_UNINSTALLED;

  }

}

/**

 * Update the installed version information for a module.

 *

 * @param $module

 *   A module name.

 * @param $version

 *   The new schema version.

 */

function drupal_set_installed_schema_version($module, $version) {

  db_update('system')

    ->fields(array('schema_version' => $version))

    ->condition('name', $module)

    ->execute();

  // Reset the static cache of module schema versions.

  drupal_get_installed_schema_version(NULL, TRUE);

}

/**

 * Loads the installation profile, extracting its defined distribution name.

 *

 * @return

 *   The distribution name defined in the profile's .info file. Defaults to

 *   "Drupal" if none is explicitly provided by the installation profile.

 *

 * @see install_profile_info()

 */

function drupal_install_profile_distribution_name() {

  // During installation, the profile information is stored in the global

  // installation state (it might not be saved anywhere yet).

  if (drupal_installation_attempted()) {

    global $install_state;

    return $install_state['profile_info']['distribution_name'];

  }

  // At all other times, we load the profile via standard methods.

  else {

    $profile = drupal_get_profile();

    $info = system_get_info('module', $profile);

    return $info['distribution_name'];

  }

}

/**

 * Detects the base URL using the PHP $_SERVER variables.

 *

 * @param $file

 *   The name of the file calling this function so we can strip it out of

 *   the URI when generating the base_url.

 *

 * @return

 *   The auto-detected $base_url that should be configured in settings.php

 */

function drupal_detect_baseurl($file = 'install.php') {

  $proto = $_SERVER['HTTPS'] ? 'https://' : 'http://';

  $host = $_SERVER['SERVER_NAME'];

  $port = ($_SERVER['SERVER_PORT'] == 80 ? '' : ':' . $_SERVER['SERVER_PORT']);

  $uri = preg_replace("/\?.*/", '', $_SERVER['REQUEST_URI']);

  $dir = str_replace("/$file", '', $uri);

  return "$proto$host$port$dir";

}

/**

 * Detects all supported databases that are compiled into PHP.

 *

 * @return

 *  An array of database types compiled into PHP.

 */

function drupal_detect_database_types() {

  $databases = drupal_get_database_types();

  foreach ($databases as $driver => $installer) {

    $databases[$driver] = $installer->name();

  }

  return $databases;

}

/**

 * Returns all supported database installer objects that are compiled into PHP.

 *

 * @return

 *  An array of database installer objects compiled into PHP.

 */

function drupal_get_database_types() {

  $databases = array();

  // We define a driver as a directory in /includes/database that in turn

  // contains a database.inc file. That allows us to drop in additional drivers

  // without modifying the installer.

  // Because we have no registry yet, we need to also include the install.inc

  // file for the driver explicitly.

  require_once DRUPAL_ROOT . '/includes/database/database.inc';

  foreach (file_scan_directory(DRUPAL_ROOT . '/includes/database', '/^[a-z]*$/i', array('recurse' => FALSE)) as $file) {

    if (file_exists($file->uri . '/database.inc') && file_exists($file->uri . '/install.inc')) {

      $drivers[$file->filename] = $file->uri;

    }

  }

  foreach ($drivers as $driver => $file) {

    $installer = db_installer_object($driver);

    if ($installer->installable()) {

      $databases[$driver] = $installer;

    }

  }

  // Usability: unconditionally put the MySQL driver on top.

  if (isset($databases['mysql'])) {

    $mysql_database = $databases['mysql'];

    unset($databases['mysql']);

    $databases = array('mysql' => $mysql_database) + $databases;

  }

  return $databases;

}

/**

 * Database installer structure.

 *

 * Defines basic Drupal requirements for databases.

 */

abstract class DatabaseTasks {

  /**

   * Structure that describes each task to run.

   *

   * @var array

   *

   * Each value of the tasks array is an associative array defining the function

   * to call (optional) and any arguments to be passed to the function.

   */

  protected $tasks = array(

    array(

      'function'    => 'checkEngineVersion',

      'arguments'   => array(),

    ),

    array(

      'arguments'   => array(

        'CREATE TABLE {drupal_install_test} (id int NULL)',

        'Drupal can use CREATE TABLE database commands.',

        'Failed to <strong>CREATE</strong> a test table on your database server with the command %query. The server reports the following message: %error.<p>Are you sure the configured username has the necessary permissions to create tables in the database?</p>',

        TRUE,

      ),

    ),

    array(

      'arguments'   => array(

        'INSERT INTO {drupal_install_test} (id) VALUES (1)',

        'Drupal can use INSERT database commands.',

        'Failed to <strong>INSERT</strong> a value into a test table on your database server. We tried inserting a value with the command %query and the server reported the following error: %error.',

      ),

    ),

    array(

      'arguments'   => array(

        'UPDATE {drupal_install_test} SET id = 2',

        'Drupal can use UPDATE database commands.',

        'Failed to <strong>UPDATE</strong> a value in a test table on your database server. We tried updating a value with the command %query and the server reported the following error: %error.',

      ),

    ),

    array(

      'arguments'   => array(

        'DELETE FROM {drupal_install_test}',

        'Drupal can use DELETE database commands.',

        'Failed to <strong>DELETE</strong> a value from a test table on your database server. We tried deleting a value with the command %query and the server reported the following error: %error.',

      ),

    ),

    array(

      'arguments'   => array(

        'DROP TABLE {drupal_install_test}',

        'Drupal can use DROP TABLE database commands.',

        'Failed to <strong>DROP</strong> a test table from your database server. We tried dropping a table with the command %query and the server reported the following error %error.',

      ),

    ),

  );

  /**

   * Results from tasks.

   *

   * @var array

   */

  protected $results = array();

  /**

   * Ensure the PDO driver is supported by the version of PHP in use.

   */

  protected function hasPdoDriver() {

    return in_array($this->pdoDriver, PDO::getAvailableDrivers());

  }

  /**

   * Assert test as failed.

   */

  protected function fail($message) {

    $this->results[$message] = FALSE;

  }

  /**

   * Assert test as a pass.

   */

  protected function pass($message) {

    $this->results[$message] = TRUE;

  }

  /**

   * Check whether Drupal is installable on the database.

   */

  public function installable() {

    return $this->hasPdoDriver() && empty($this->error);

  }

  /**

   * Return the human-readable name of the driver.

   */

  abstract public function name();

  /**

   * Return the minimum required version of the engine.

   *

   * @return

   *   A version string. If not NULL, it will be checked against the version

   *   reported by the Database engine using version_compare().

   */

  public function minimumVersion() {

    return NULL;

  }

  /**

   * Run database tasks and tests to see if Drupal can run on the database.

   */

  public function runTasks() {

    // We need to establish a connection before we can run tests.

    if ($this->connect()) {

      foreach ($this->tasks as $task) {

        if (!isset($task['function'])) {

          $task['function'] = 'runTestQuery';

        }

        if (method_exists($this, $task['function'])) {

          // Returning false is fatal. No other tasks can run.

          if (FALSE === call_user_func_array(array($this, $task['function']), $task['arguments'])) {

            break;

          }

        }

        else {

          throw new DatabaseTaskException(st("Failed to run all tasks against the database server. The task %task wasn't found.", array('%task' => $task['function'])));

        }

      }

    }

    // Check for failed results and compile message

    $message = '';

    foreach ($this->results as $result => $success) {

      if (!$success) {

        $message .= '<p class="error">' . $result  . '</p>';

      }

    }

    if (!empty($message)) {

      $message = 'Resolve all issues below to continue the installation. For help configuring your database server, see the <a href="http://drupal.org/getting-started/install">installation handbook</a>, or contact your hosting provider.' . $message;

      throw new DatabaseTaskException($message);

    }

  }

  /**

   * Check if we can connect to the database.

   */

  protected function connect() {

    try {

      // This doesn't actually test the connection.

      db_set_active();

      // Now actually do a check.

      Database::getConnection();

      $this->pass('Drupal can CONNECT to the database ok.');

    }

    catch (Exception $e) {

      $this->fail(st('Failed to connect to your database server. The server reports the following message: %error.<ul><li>Is the database server running?</li><li>Does the database exist, and have you entered the correct database name?</li><li>Have you entered the correct username and password?</li><li>Have you entered the correct database hostname?</li></ul>', array('%error' => $e->getMessage())));

      return FALSE;

    }

    return TRUE;

  }

  /**

   * Run SQL tests to ensure the database can execute commands with the current user.

   */

  protected function runTestQuery($query, $pass, $fail, $fatal = FALSE) {

    try {

      db_query($query);

      $this->pass(st($pass));

    }

    catch (Exception $e) {

      $this->fail(st($fail, array('%query' => $query, '%error' => $e->getMessage(), '%name' => $this->name())));

      return !$fatal;

    }

  }

  /**

   * Check the engine version.

   */

  protected function checkEngineVersion() {

    if ($this->minimumVersion() && version_compare(Database::getConnection()->version(), $this->minimumVersion(), '<')) {

      $this->fail(st("The database version %version is less than the minimum required version %minimum_version.", array('%version' => Database::getConnection()->version(), '%minimum_version' => $this->minimumVersion())));

    }

  }

  /**

   * Return driver specific configuration options.

   *

   * @param $database

   *  An array of driver specific configuration options.

   *

   * @return

   *   The options form array.

   */

  public function getFormOptions($database) {

    $form['database'] = array(

      '#type' => 'textfield',

      '#title' => st('Database name'),

      '#default_value' => empty($database['database']) ? '' : $database['database'],

      '#size' => 45,

      '#required' => TRUE,

      '#description' => st('The name of the database your @drupal data will be stored in. It must exist on your server before @drupal can be installed.', array('@drupal' => drupal_install_profile_distribution_name())),

    );

    $form['username'] = array(

      '#type' => 'textfield',

      '#title' => st('Database username'),

      '#default_value' => empty($database['username']) ? '' : $database['username'],

      '#required' => TRUE,

      '#size' => 45,

    );

    $form['password'] = array(

      '#type' => 'password',

      '#title' => st('Database password'),

      '#default_value' => empty($database['password']) ? '' : $database['password'],

      '#required' => FALSE,

      '#size' => 45,

    );

    $form['advanced_options'] = array(

      '#type' => 'fieldset',

      '#title' => st('Advanced options'),

      '#collapsible' => TRUE,

      '#collapsed' => TRUE,

      '#description' => st("These options are only necessary for some sites. If you're not sure what you should enter here, leave the default settings or check with your hosting provider."),

      '#weight' => 10,

    );

    $profile = drupal_get_profile();

    $db_prefix = ($profile == 'standard') ? 'drupal_' : $profile . '_';

    $form['advanced_options']['db_prefix'] = array(

      '#type' => 'textfield',

      '#title' => st('Table prefix'),

      '#default_value' => '',

      '#size' => 45,

      '#description' => st('If more than one application will be sharing this database, enter a table prefix such as %prefix for your @drupal site here.', array('@drupal' => drupal_install_profile_distribution_name(), '%prefix' => $db_prefix)),

      '#weight' => 10,

    );

    $form['advanced_options']['host'] = array(

      '#type' => 'textfield',

      '#title' => st('Database host'),

      '#default_value' => empty($database['host']) ? 'localhost' : $database['host'],

      '#size' => 45,

      // Hostnames can be 255 characters long.

      '#maxlength' => 255,

      '#required' => TRUE,

      '#description' => st('If your database is located on a different server, change this.'),

    );

    $form['advanced_options']['port'] = array(

      '#type' => 'textfield',

      '#title' => st('Database port'),

      '#default_value' => empty($database['port']) ? '' : $database['port'],

      '#size' => 45,

      // The maximum port number is 65536, 5 digits.

      '#maxlength' => 5,

      '#description' => st('If your database server is listening to a non-standard port, enter its number.'),

    );

    return $form;

  }

  /**

   * Validates driver specific configuration settings.

   *

   * Checks to ensure correct basic database settings and that a proper

   * connection to the database can be established.

   *

   * @param $database

   *   An array of driver specific configuration options.

   *

   * @return

   *   An array of driver configuration errors, keyed by form element name.

   */

  public function validateDatabaseSettings($database) {

    $errors = array();

    // Verify the table prefix.

    if (!empty($database['prefix']) && is_string($database['prefix']) && !preg_match('/^[A-Za-z0-9_.]+$/', $database['prefix'])) {

      $errors[$database['driver'] . '][advanced_options][db_prefix'] = st('The database table prefix you have entered, %prefix, is invalid. The table prefix can only contain alphanumeric characters, periods, or underscores.', array('%prefix' => $database['prefix']));

    }

    // Verify the database port.

    if (!empty($database['port']) && !is_numeric($database['port'])) {

      $errors[$database['driver'] . '][advanced_options][port'] =  st('Database port must be a number.');

    }

    return $errors;

  }

}

/**

 * Exception thrown if the database installer fails.

 */

class DatabaseTaskException extends Exception {

}

/**

 * Replaces values in settings.php with values in the submitted array.

 *

 * @param $settings

 *   An array of settings that need to be updated.

 */

function drupal_rewrite_settings($settings = array(), $prefix = '') {

  $default_settings = 'sites/default/default.settings.php';

  drupal_static_reset('conf_path');

  $settings_file = conf_path(FALSE) . '/' . $prefix . 'settings.php';

  // Build list of setting names and insert the values into the global namespace.

  $keys = array();

  foreach ($settings as $setting => $data) {

    $GLOBALS[$setting] = $data['value'];

    $keys[] = $setting;

  }

  $buffer = NULL;

  $first = TRUE;

  if ($fp = fopen(DRUPAL_ROOT . '/' . $default_settings, 'r')) {

    // Step line by line through settings.php.

    while (!feof($fp)) {

      $line = fgets($fp);

      if ($first && substr($line, 0, 5) != '<?php') {

        $buffer = "<?php\n\n";

      }

      $first = FALSE;

      // Check for constants.

      if (substr($line, 0, 7) == 'define(') {

        preg_match('/define\(\s*[\'"]([A-Z_-]+)[\'"]\s*,(.*?)\);/', $line, $variable);

        if (in_array($variable[1], $keys)) {

          $setting = $settings[$variable[1]];

          $buffer .= str_replace($variable[2], " '" . $setting['value'] . "'", $line);

          unset($settings[$variable[1]]);

          unset($settings[$variable[2]]);

        }

        else {

          $buffer .= $line;

        }

      }

      // Check for variables.

      elseif (substr($line, 0, 1) == '$') {

        preg_match('/\$([^ ]*) /', $line, $variable);

        if (in_array($variable[1], $keys)) {

          // Write new value to settings.php in the following format:

          //    $'setting' = 'value'; // 'comment'

          $setting = $settings[$variable[1]];

          $buffer .= '$' . $variable[1] . " = " . var_export($setting['value'], TRUE) . ";" . (!empty($setting['comment']) ? ' // ' . $setting['comment'] . "\n" : "\n");

          unset($settings[$variable[1]]);

        }

        else {

          $buffer .= $line;

        }

      }

      else {

        $buffer .= $line;

      }

    }

    fclose($fp);

    // Add required settings that were missing from settings.php.

    foreach ($settings as $setting => $data) {

      if ($data['required']) {

        $buffer .= "\$$setting = " . var_export($data['value'], TRUE) . ";\n";

      }

    }

    $fp = fopen(DRUPAL_ROOT . '/' . $settings_file, 'w');

    if ($fp && fwrite($fp, $buffer) === FALSE) {

      throw new Exception(st('Failed to modify %settings. Verify the file permissions.', array('%settings' => $settings_file)));

    }

  }

  else {

    throw new Exception(st('Failed to open %settings. Verify the file permissions.', array('%settings' => $default_settings)));

  }

}

/**

 * Verifies an installation profile for installation.

 *

 * @param $install_state

 *   An array of information about the current installation state.

 *

 * @return

 *   The list of modules to install.

 */

function drupal_verify_profile($install_state) {

  $profile = $install_state['parameters']['profile'];

  $locale = $install_state['parameters']['locale'];

  include_once DRUPAL_ROOT . '/includes/file.inc';

  include_once DRUPAL_ROOT . '/includes/common.inc';

  $profile_file = DRUPAL_ROOT . "/profiles/$profile/$profile.profile";

  if (!isset($profile) || !file_exists($profile_file)) {

    throw new Exception(install_no_profile_error());

  }

  $info = $install_state['profile_info'];

  // Get a list of modules that exist in Drupal's assorted subdirectories.

  $present_modules = array();

  foreach (drupal_system_listing('/^' . DRUPAL_PHP_FUNCTION_PATTERN . '\.module$/', 'modules', 'name', 0) as $present_module) {

    $present_modules[] = $present_module->name;

  }

  // The installation profile is also a module, which needs to be installed

  // after all the other dependencies have been installed.

  $present_modules[] = drupal_get_profile();

  // Verify that all of the profile's required modules are present.

  $missing_modules = array_diff($info['dependencies'], $present_modules);

  $requirements = array();

  if (count($missing_modules)) {

    $modules = array();

    foreach ($missing_modules as $module) {

      $modules[] = '<span class="admin-missing">' . drupal_ucfirst($module) . '</span>';

    }

    $requirements['required_modules'] = array(

      'title'       => st('Required modules'),

      'value'       => st('Required modules not found.'),

      'severity'    => REQUIREMENT_ERROR,

      'description' => st('The following modules are required but were not found. Move them into the appropriate modules subdirectory, such as <em>sites/all/modules</em>. Missing modules: !modules', array('!modules' => implode(', ', $modules))),

    );

  }

  return $requirements;

}

/**

 * Installs the system module.

 *

 * Separated from the installation of other modules so core system

 * functions can be made available while other modules are installed.

 */

function drupal_install_system() {

  $system_path = drupal_get_path('module', 'system');

  require_once DRUPAL_ROOT . '/' . $system_path . '/system.install';

  module_invoke('system', 'install');

  $system_versions = drupal_get_schema_versions('system');

  $system_version = $system_versions ? max($system_versions) : SCHEMA_INSTALLED;

  db_insert('system')

    ->fields(array('filename', 'name', 'type', 'owner', 'status', 'schema_version', 'bootstrap'))

    ->values(array(

        'filename' => $system_path . '/system.module',

        'name' => 'system',

        'type' => 'module',

        'owner' => '',

        'status' => 1,

        'schema_version' => $system_version,

        'bootstrap' => 0,

      ))

    ->execute();

  system_rebuild_module_data();

}

/**

 * Uninstalls a given list of disabled modules.

 *

 * @param array $module_list

 *   The modules to uninstall. It is the caller's responsibility to ensure that

 *   all modules in this list have already been disabled before this function

 *   is called.

 * @param bool $uninstall_dependents

 *   (optional) If TRUE, the function will check that all modules which depend

 *   on the passed-in module list either are already uninstalled or contained in

 *   the list, and it will ensure that the modules are uninstalled in the

 *   correct order. This incurs a significant performance cost, so use FALSE if

 *   you know $module_list is already complete and in the correct order.

 *   Defaults to TRUE.

 *

 * @return bool

 *   Returns TRUE if the operation succeeds or FALSE if it aborts due to an

 *   unsafe condition, namely, $uninstall_dependents is TRUE and a module in

 *   $module_list has dependents which are not already uninstalled and not also

 *   included in $module_list).

 *

 * @see module_disable()

 */

function drupal_uninstall_modules($module_list = array(), $uninstall_dependents = TRUE) {

  if ($uninstall_dependents) {

    // Get all module data so we can find dependents and sort.

    $module_data = system_rebuild_module_data();

    // Create an associative array with weights as values.

    $module_list = array_flip(array_values($module_list));

    $profile = drupal_get_profile();

    while (list($module) = each($module_list)) {

      if (!isset($module_data[$module]) || drupal_get_installed_schema_version($module) == SCHEMA_UNINSTALLED) {

        // This module doesn't exist or is already uninstalled. Skip it.

        unset($module_list[$module]);

        continue;

      }

      $module_list[$module] = $module_data[$module]->sort;

      // If the module has any dependents which are not already uninstalled and

      // not included in the passed-in list, abort. It is not safe to uninstall

      // them automatically because uninstalling a module is a destructive

      // operation.

      foreach (array_keys($module_data[$module]->required_by) as $dependent) {

        if (!isset($module_list[$dependent]) && drupal_get_installed_schema_version($dependent) != SCHEMA_UNINSTALLED && $dependent != $profile) {

          return FALSE;

        }

      }

    }

    // Sort the module list by pre-calculated weights.

    asort($module_list);

    $module_list = array_keys($module_list);

  }

  foreach ($module_list as $module) {

    // Uninstall the module.

    module_load_install($module);

    module_invoke($module, 'uninstall');

    drupal_uninstall_schema($module);

    watchdog('system', '%module module uninstalled.', array('%module' => $module), WATCHDOG_INFO);

    drupal_set_installed_schema_version($module, SCHEMA_UNINSTALLED);

  }

  if (!empty($module_list)) {

    // Let other modules react.

    module_invoke_all('modules_uninstalled', $module_list);

  }

  return TRUE;

}

/**

 * Verifies the state of the specified file.

 *

 * @param $file

 *   The file to check for.

 * @param $mask

 *   An optional bitmask created from various FILE_* constants.

 * @param $type

 *   The type of file. Can be file (default), dir, or link.

 *

 * @return

 *   TRUE on success or FALSE on failure. A message is set for the latter.

 */

function drupal_verify_install_file($file, $mask = NULL, $type = 'file') {

  $return = TRUE;

  // Check for files that shouldn't be there.

  if (isset($mask) && ($mask & FILE_NOT_EXIST) && file_exists($file)) {

    return FALSE;

  }

  // Verify that the file is the type of file it is supposed to be.

  if (isset($type) && file_exists($file)) {

    $check = 'is_' . $type;

    if (!function_exists($check) || !$check($file)) {

      $return = FALSE;

    }

  }

  // Verify file permissions.

  if (isset($mask)) {

    $masks = array(FILE_EXIST, FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);

    foreach ($masks as $current_mask) {

      if ($mask & $current_mask) {

        switch ($current_mask) {

          case FILE_EXIST:

            if (!file_exists($file)) {

              if ($type == 'dir') {

                drupal_install_mkdir($file, $mask);

              }

              if (!file_exists($file)) {

                $return = FALSE;

              }

            }

            break;

          case FILE_READABLE:

            if (!is_readable($file) && !drupal_install_fix_file($file, $mask)) {

              $return = FALSE;

            }

            break;

          case FILE_WRITABLE:

            if (!is_writable($file) && !drupal_install_fix_file($file, $mask)) {

              $return = FALSE;

            }

            break;

          case FILE_EXECUTABLE:

            if (!is_executable($file) && !drupal_install_fix_file($file, $mask)) {

              $return = FALSE;

            }

            break;

          case FILE_NOT_READABLE:

            if (is_readable($file) && !drupal_install_fix_file($file, $mask)) {

              $return = FALSE;

            }

            break;

          case FILE_NOT_WRITABLE:

            if (is_writable($file) && !drupal_install_fix_file($file, $mask)) {

              $return = FALSE;

            }

            break;

          case FILE_NOT_EXECUTABLE:

            if (is_executable($file) && !drupal_install_fix_file($file, $mask)) {

              $return = FALSE;

            }

            break;

        }

      }

    }

  }

  return $return;

}

/**

 * Creates a directory with the specified permissions.

 *

 * @param $file

 *  The name of the directory to create;

 * @param $mask

 *  The permissions of the directory to create.

 * @param $message

 *  (optional) Whether to output messages. Defaults to TRUE.

 *

 * @return

 *  TRUE/FALSE whether or not the directory was successfully created.

 */

function drupal_install_mkdir($file, $mask, $message = TRUE) {

  $mod = 0;

  $masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);

  foreach ($masks as $m) {

    if ($mask & $m) {

      switch ($m) {

        case FILE_READABLE:

          $mod |= 0444;

          break;

        case FILE_WRITABLE:

          $mod |= 0222;

          break;

        case FILE_EXECUTABLE:

          $mod |= 0111;

          break;

      }

    }

  }

  if (@drupal_mkdir($file, $mod)) {

    return TRUE;

  }

  else {

    return FALSE;

  }

}

/**

 * Attempts to fix file permissions.

 *

 * The general approach here is that, because we do not know the security

 * setup of the webserver, we apply our permission changes to all three

 * digits of the file permission (i.e. user, group and all).

 *

 * To ensure that the values behave as expected (and numbers don't carry

 * from one digit to the next) we do the calculation on the octal value

 * using bitwise operations. This lets us remove, for example, 0222 from

 * 0700 and get the correct value of 0500.

 *

 * @param $file

 *  The name of the file with permissions to fix.

 * @param $mask

 *  The desired permissions for the file.

 * @param $message

 *  (optional) Whether to output messages. Defaults to TRUE.

 *

 * @return

 *  TRUE/FALSE whether or not we were able to fix the file's permissions.

 */

function drupal_install_fix_file($file, $mask, $message = TRUE) {

  // If $file does not exist, fileperms() issues a PHP warning.

  if (!file_exists($file)) {

    return FALSE;

  }

  $mod = fileperms($file) & 0777;

  $masks = array(FILE_READABLE, FILE_WRITABLE, FILE_EXECUTABLE, FILE_NOT_READABLE, FILE_NOT_WRITABLE, FILE_NOT_EXECUTABLE);

  // FILE_READABLE, FILE_WRITABLE, and FILE_EXECUTABLE permission strings

  // can theoretically be 0400, 0200, and 0100 respectively, but to be safe

  // we set all three access types in case the administrator intends to

  // change the owner of settings.php after installation.

  foreach ($masks as $m) {

    if ($mask & $m) {

      switch ($m) {

        case FILE_READABLE:

          if (!is_readable($file)) {

            $mod |= 0444;

          }

          break;

        case FILE_WRITABLE:

          if (!is_writable($file)) {

            $mod |= 0222;

          }

          break;

        case FILE_EXECUTABLE:

          if (!is_executable($file)) {

            $mod |= 0111;

          }

          break;

        case FILE_NOT_READABLE:

          if (is_readable($file)) {

            $mod &= ~0444;

          }

          break;

        case FILE_NOT_WRITABLE:

          if (is_writable($file)) {

            $mod &= ~0222;

          }

          break;

        case FILE_NOT_EXECUTABLE:

          if (is_executable($file)) {

            $mod &= ~0111;

          }

          break;

      }

    }

  }

  // chmod() will work if the web server is running as owner of the file.

  // If PHP safe_mode is enabled the currently executing script must also

  // have the same owner.

  if (@chmod($file, $mod)) {

    return TRUE;

  }

  else {

    return FALSE;

  }

}

/**

 * Sends the user to a different installer page.

 *

 * This issues an on-site HTTP redirect. Messages (and errors) are erased.

 *

 * @param $path

 *   An installer path.

 */

function install_goto($path) {

  global $base_url;

  include_once DRUPAL_ROOT . '/includes/common.inc';

  header('Location: ' . $base_url . '/' . $path);

  header('Cache-Control: no-cache'); // Not a permanent redirect.

  drupal_exit();

}

/**

 * Returns the URL of the current script, with modified query parameters.

 *

 * This function can be called by low-level scripts (such as install.php and

 * update.php) and returns the URL of the current script. Existing query

 * parameters are preserved by default, but new ones can optionally be merged

 * in.

 *

 * This function is used when the script must maintain certain query parameters

 * over multiple page requests in order to work correctly. In such cases (for

 * example, update.php, which requires the 'continue=1' parameter to remain in

 * the URL throughout the update process if there are any requirement warnings

 * that need to be bypassed), using this function to generate the URL for links

 * to the next steps of the script ensures that the links will work correctly.

 *

 * @param $query

 *   (optional) An array of query parameters to merge in to the existing ones.

 *

 * @return

 *   The URL of the current script, with query parameters modified by the

 *   passed-in $query. The URL is not sanitized, so it still needs to be run

 *   through check_url() if it will be used as an HTML attribute value.

 *

 * @see drupal_requirements_url()

 */

function drupal_current_script_url($query = array()) {

  $uri = $_SERVER['SCRIPT_NAME'];

  $query = array_merge(drupal_get_query_parameters(), $query);

  if (!empty($query)) {

    $uri .= '?' . drupal_http_build_query($query);

  }

  return $uri;

}

/**

 * Returns a URL for proceeding to the next page after a requirements problem.

 *

 * This function can be called by low-level scripts (such as install.php and

 * update.php) and returns a URL that can be used to attempt to proceed to the

 * next step of the script.

 *

 * @param $severity

 *   The severity of the requirements problem, as returned by

 *   drupal_requirements_severity().

 *

 * @return

 *   A URL for attempting to proceed to the next step of the script. The URL is

 *   not sanitized, so it still needs to be run through check_url() if it will

 *   be used as an HTML attribute value.

 *

 * @see drupal_current_script_url()

 */

function drupal_requirements_url($severity) {

  $query = array();

  // If there are no errors, only warnings, append 'continue=1' to the URL so

  // the user can bypass this screen on the next page load.

  if ($severity == REQUIREMENT_WARNING) {

    $query['continue'] = 1;

  }

  return drupal_current_script_url($query);

}

/**

 * Translates a string when some systems are not available.

 *

 * Used during the install process, when database, theme, and localization

 * system is possibly not yet available.

 *

 * Use t() if your code will never run during the Drupal installation phase.

 * Use st() if your code will only run during installation and never any other

 * time. Use get_t() if your code could run in either circumstance.

 *

 * @see t()

 * @see get_t()

 * @ingroup sanitization

 */

function st($string, array $args = array(), array $options = array()) {

  static $locale_strings = NULL;

  global $install_state;

  if (empty($options['context'])) {

    $options['context'] = '';

  }

  if (!isset($locale_strings)) {

    $locale_strings = array();

    if (isset($install_state['parameters']['profile']) && isset($install_state['parameters']['locale'])) {

      // If the given locale was selected, there should be at least one .po file

      // with its name ending in {$install_state['parameters']['locale']}.po

      // This might or might not be the entire filename. It is also possible