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html - PHP making a download counter without leaving the current page

I tried to create a download counter with PHP. The script, I have created, works, but when I click the download link, the script sends me to a blank page. Is it possible to stay on the page while downloading and counting?

Here's my code of my download.php file:

<?php
$Down=$_GET['Down'];
?>

<html>
<head>

<meta http-equiv="refresh" content="0;url=<?php echo $Down; ?>">

</head>

<body>

<?php

$fp = fopen("counter.txt", "r");
$count = fread($fp, 1024);
fclose($fp);
$count = $count + 1;

$fp = fopen("counter.txt", "w");
fwrite($fp, $count);
fclose($fp);


?>

</body>
</html>

That's how the link in my index.php looks like:

<a href="download.php?Down=download.zip">download</a>

Many thanks in advance!

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1 Answer

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by (71.8m points)

Ok as you have most of the code missing here is an example, basically your need to call the counter code inside the download.php file, and pass through the file contents after doing the counter code and setting download headers. also be wary or allowing malicious people to download any file from your server by just passing the file name to the download function. download.php?file=index.php ect

<?php 
function get_download_count($file=null){
    $counters = './counters/';
    if($file == null) return 0;
    $count = 0;
    if(file_exists($counters.md5($file).'_counter.txt')){
        $fp = fopen($counters.md5($file).'_counter.txt', "r");
        $count = fread($fp, 1024);
        fclose($fp);
    }else{
        $fp = fopen($counters.md5($file).'_counter.txt', "w+");
        fwrite($fp, $count);
        fclose($fp);
    }
    return $count;
}
?>
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title></title>
</head>

<body>

<a href="./download.php?file=exampleA.zip">exampleA.zip</a> (Downloaded <?php echo get_download_count('exampleA.zip');?> times)<br>
<a href="./download.php?file=exampleB.zip">exampleB.zip</a> (Downloaded <?php echo get_download_count('exampleB.zip');?> times)<br>

</body>
</html>

download.php as you can see it outputs no HTML as this would corrupt the file.

<?php 
//where the files are
$downloads_folder = './files/';
$counters_folder = './counters/';

//has a file name been passed?
if(!empty($_GET['file'])){
    //protect from people getting other files
    $file = basename($_GET['file']);

    //does the file exist?
    if(file_exists($downloads_folder.$file)){

        //update counter - add if dont exist
        if(file_exists($counters_folder.md5($file).'_counter.txt')){
            $fp = fopen($counters_folder.md5($file).'_counter.txt', "r");
            $count = fread($fp, 1024);
            fclose($fp);
            $fp = fopen($counters_folder.md5($file).'_counter.txt', "w");
            fwrite($fp, $count + 1);
            fclose($fp);
        }else{
            $fp = fopen($counters_folder.md5($file).'_counter.txt', "w+");
            fwrite($fp, 1);
            fclose($fp);
        }

        //set force download headers
        header('Content-Description: File Transfer');
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename="'.$file.'"');
        header('Content-Transfer-Encoding: binary');
        header('Connection: Keep-Alive');
        header('Expires: 0');
        header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
        header('Pragma: public');
        header('Content-Length: ' . sprintf("%u", filesize($downloads_folder.$file)));

        //open and output file contents
        $fh = fopen($downloads_folder.$file, "rb");
        while (!feof($fh)) {
            echo fgets($fh);
            flush();
        }
        fclose($fh);
        exit;
    }else{
        header("HTTP/1.0 404 Not Found");
        exit('File not found!');
    }
}else{
    exit(header("Location: ./index.php"));
}
?>

Make sure you check the $downloads_folder variable is correct. Hope it helps.

Download Full example code.


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