function install_check_requirements

Checks installation requirements and reports any errors.

File

includes/install.core.inc, line 1639

Code

function install_check_requirements($install_state) {
    $profile = $install_state['parameters']['profile'];
    // Check the profile requirements.
    $requirements = drupal_check_profile($profile);
    // If Drupal is not set up already, we need to create a settings file.
    if (!$install_state['settings_verified']) {
        $writable = FALSE;
        $conf_path = './' . conf_path(FALSE, TRUE);
        $settings_file = $conf_path . '/settings.php';
        $default_settings_file = './sites/default/default.settings.php';
        $file = $conf_path;
        $exists = FALSE;
        // Verify that the directory exists.
        if (drupal_verify_install_file($conf_path, FILE_EXIST, 'dir')) {
            // Check if a settings.php file already exists.
            $file = $settings_file;
            if (drupal_verify_install_file($settings_file, FILE_EXIST)) {
                // If it does, make sure it is writable.
                $writable = drupal_verify_install_file($settings_file, FILE_READABLE | FILE_WRITABLE);
                $exists = TRUE;
            }
        }
        // If default.settings.php does not exist, or is not readable, throw an
        // error.
        if (!drupal_verify_install_file($default_settings_file, FILE_EXIST | FILE_READABLE)) {
            $requirements['default settings file exists'] = array(
                'title' => st('Default settings file'),
                'value' => st('The default settings file does not exist.'),
                'severity' => REQUIREMENT_ERROR,
                'description' => st('The @drupal installer requires that the %default-file file not be modified in any way from the original download.', array(
                    '@drupal' => drupal_install_profile_distribution_name(),
                    '%default-file' => $default_settings_file,
                )),
            );
        }
        elseif (!$exists) {
            $copied = drupal_verify_install_file($conf_path, FILE_EXIST | FILE_WRITABLE, 'dir') && @copy($default_settings_file, $settings_file);
            if ($copied) {
                // If the new settings file has the same owner as default.settings.php,
                // this means default.settings.php is owned by the webserver user.
                // This is an inherent security weakness because it allows a malicious
                // webserver process to append arbitrary PHP code and then execute it.
                // However, it is also a common configuration on shared hosting, and
                // there is nothing Drupal can do to prevent it. In this situation,
                // having settings.php also owned by the webserver does not introduce
                // any additional security risk, so we keep the file in place.
                if (fileowner($default_settings_file) === fileowner($settings_file)) {
                    $writable = drupal_verify_install_file($settings_file, FILE_READABLE | FILE_WRITABLE);
                    $exists = TRUE;
                }
                else {
                    $deleted = @drupal_unlink($settings_file);
                    // We expect deleting the file to be successful (since we just
                    // created it ourselves above), but if it fails somehow, we set a
                    // variable so we can display a one-time error message to the
                    // administrator at the bottom of the requirements list. We also try
                    // to make the file writable, to eliminate any conflicting error
                    // messages in the requirements list.
                    $exists = !$deleted;
                    if ($exists) {
                        $settings_file_ownership_error = TRUE;
                        $writable = drupal_verify_install_file($settings_file, FILE_READABLE | FILE_WRITABLE);
                    }
                }
            }
        }
        // If settings.php does not exist, throw an error.
        if (!$exists) {
            $requirements['settings file exists'] = array(
                'title' => st('Settings file'),
                'value' => st('The settings file does not exist.'),
                'severity' => REQUIREMENT_ERROR,
                'description' => st('The @drupal installer requires that you create a settings file as part of the installation process. Copy the %default_file file to %file. More details about installing Drupal are available in <a href="@install_txt">INSTALL.txt</a>.', array(
                    '@drupal' => drupal_install_profile_distribution_name(),
                    '%file' => $file,
                    '%default_file' => $default_settings_file,
                    '@install_txt' => base_path() . 'INSTALL.txt',
                )),
            );
        }
        else {
            $requirements['settings file exists'] = array(
                'title' => st('Settings file'),
                'value' => st('The %file file exists.', array(
                    '%file' => $file,
                )),
            );
            // If settings.php is not writable, throw an error.
            if (!$writable) {
                $requirements['settings file writable'] = array(
                    'title' => st('Settings file'),
                    'value' => st('The settings file is not writable.'),
                    'severity' => REQUIREMENT_ERROR,
                    'description' => st('The @drupal installer requires write permissions to %file during the installation process. If you are unsure how to grant file permissions, consult the <a href="@handbook_url">online handbook</a>.', array(
                        '@drupal' => drupal_install_profile_distribution_name(),
                        '%file' => $file,
                        '@handbook_url' => 'http://drupal.org/server-permissions',
                    )),
                );
            }
            else {
                $requirements['settings file'] = array(
                    'title' => st('Settings file'),
                    'value' => st('The settings file is writable.'),
                );
            }
            if (!empty($settings_file_ownership_error)) {
                $requirements['settings file ownership'] = array(
                    'title' => st('Settings file'),
                    'value' => st('The settings file is owned by the web server.'),
                    'severity' => REQUIREMENT_ERROR,
                    'description' => st('The @drupal installer failed to create a settings file with proper file ownership. Log on to your web server, remove the existing %file file, and create a new one by copying the %default_file file to %file. More details about installing Drupal are available in <a href="@install_txt">INSTALL.txt</a>. If you have problems with the file permissions on your server, consult the <a href="@handbook_url">online handbook</a>.', array(
                        '@drupal' => drupal_install_profile_distribution_name(),
                        '%file' => $file,
                        '%default_file' => $default_settings_file,
                        '@install_txt' => base_path() . 'INSTALL.txt',
                        '@handbook_url' => 'http://drupal.org/server-permissions',
                    )),
                );
            }
        }
    }
    return $requirements;
}