source: trunk/install/srtm_download.php @ 244

<?php
/*
 * WiND - Wireless Nodes Database
 *
 * Copyright (C) 2011 K. Paliouras <squarious _at gmail [dot] com>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 dated June, 1991.
 *
 * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

ini_set('max_execution_time', 300);
header('Content-Type: application/json');

require_once dirname(__FILE__) . '/../globals/classes/srtm.php';

if (!isset($_GET['lat']) || !isset($_GET['lng']))
        return;
        
$base_url = 'http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/';
$srtm_directory = dirname(__FILE__) . '/../files/srtm/';
$fname = srtm::get_filename((int)$_GET['lat'], (int)$_GET['lng']);
$zip_fname = $fname . '.zip';
$regions = array(
        'Africa',
        'Australia',
        'Eurasia',
        'Islands',
        'North_America',
        'South_America'
);

/*
 * Search file in all regions
 */
foreach($regions as $region) {

        if (!($srtm_data = @file_get_contents($base_url . '/' . $region .'/' . $zip_fname)))
                continue;
        
        file_put_contents($srtm_directory . $zip_fname, $srtm_data);
        if (!($zip = zip_open($srtm_directory . $zip_fname))){
                echo json_encode(array('result' => '500', 'error' => 'cannot unzip'));
                return;
        }
        while($e = zip_read($zip)) {
                if (zip_entry_name($e) !== $fname)
                        continue;
                        
                zip_entry_open($zip, $e, "r");
                
                $uncompressed = zip_entry_read($e, zip_entry_filesize($e));
                file_put_contents($srtm_directory . $fname, $uncompressed);
                zip_close($zip);
                unlink($srtm_directory . $zip_fname);
                echo json_encode(array('result' => 'ok'));
                return;
        }
}

echo json_encode(array('result' => '404'));
return;