how to check connection to php page
I might have written the title wrong. Sorry for that.
I just wonder if there is a way to check users connection to a php page.
For example, i have a php page called "download.php" and this page lets user to download sth and insert this action to mysql, like that
$query = "INSERT INTO bla bla ";
$result = mysql_query($query);
header('Content-type: application/zip');
header('Content-Length: ' . filesize($file));
header("Content-Disposition: attachment; filename="file.zip");
readfile($file);
But sometimes, download manager softwares like "orbit" etc... connect this pag开发者_开发知识库e hundreds of time, and blow up the database.
is there a way to prevent this ?
Thanks
You can specify the number of allowed connections in your sql configuration or apache. Set max connections to something you know your database can handle
Edit the file /etc/my.cnf max_connections=1000
The best thing to do is drop the MySQL connection before the download starts, as it remains open during the whole download. Reconnect at the end if necessary - the problem should go away.
That is, after the last use of MySQL, but before the headers, put
mysql_close();
If I understand correctly, you want to filter out requests from download managers or bots and only record the actual user in your database. There are a few methods I can think of to accomplish this:
Filter the User Agent: every request should send a user-agent header, which identifies the browser or software making the request. You could use this method to filter out bots and download managers (if in fact they are using a separate user-agent). Here is an example script that does this.
Use a Cookie: something like this at the top of the page, assuming the download manager shares cookie state with the browser:
if (!isset($_COOKIE['download_check'])) {
setcookie('download_check', '1', 0, '/');
} else {
exit();
}
The script will not do anything after the first time. To allow the user to come back and re-download, just destroy the cookie on any other page.
Redirect with JavaScript or meta-tags: Assuming that the downloader or a bot will not execute JavaScript, check for the existence of some parameter in the query string. If it does not exist, then output a short page with a JavaScript or meta-tag redirect to the same page with the parameter and exit, like this:
if (!isset($_GET['download_check'])) {
echo "<html><script>window.location = 'this_page.php?download_check=1'</script></html>";
exit();
}
I hope that one or more of these methods helps you filter out incorrect requests to your application.
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