source: extensions/database_migration/include/tab_restore.inc.php

<?php
// +-----------------------------------------------------------------------+
// | database_migration - a plugin for Piwigo                              |
// +-----------------------------------------------------------------------+
// | Copyright(C) 2010 Nicolas Roudaire             http://www.nikrou.net  |
// +-----------------------------------------------------------------------+
// | This program is free software; you can redistribute it and/or modify  |
// | it under the terms of the GNU General Public License version 2 as     |
// | published by the Free Software Foundation                             |
// |                                                                       |
// | This program is distributed in the hope that it will be useful, but   |
// | WITHOUT ANY WARRANTY; without even the implied warranty of            |
// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      |
// | General Public License for more details.                              |
// |                                                                       |
// | You should have received a copy of the GNU General Public License     |
// | along with this program; if not, write to the Free Software           |
// | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,            |
// | MA 02110-1301 USA                                                     |
// +-----------------------------------------------------------------------+

if (!empty($_GET['dl']) && file_exists($conf['local_data_dir'].'/dm_'.$_GET['dl']))
{
  $filename = $conf['local_data_dir'].'/dm_'.$_GET['dl'];
  header('Cache-Control: no-cache, must-revalidate');
  header('Pragma: no-cache');
  header('Content-Disposition: attachment; filename="database.inc.php"');
  header('Content-Transfer-Encoding: binary');
  header('Content-Length: '.filesize($filename));
  echo file_get_contents($filename);
  unlink($filename);
  exit();
} 

include_once DM_PLUGIN_ROOT . '/include/functions.inc.php';

load_language('install.lang', PHPWG_ROOT_PATH);

$connection = $me->getConnection('mysql');
$file_content = get_config_file_content('mysql', $connection);
$config_file = PHPWG_ROOT_PATH . 'local/config/database.inc.php';

if ( !($fp=@fopen( $config_file, 'w' ))) {
  $tmp_filename = md5(uniqid('', true));
  $fh = @fopen( $conf['local_data_dir'] . '/dm_' . $tmp_filename, 'w' );
  @fputs($fh, $file_content, strlen($file_content));
  @fclose($fh);
  
  $template->assign(array('config_creation_failed' => true,
                          'config_url' => $dm_base_url.'&amp;tab=migration&amp;dl='.$tmp_filename,
                          'config_file_content' => $file_content,
                          )
                    );
}
@fputs($fp, $file_content, strlen($file_content));
@fclose($fp);
?>