PHP - Number of times downloaded

问题:

How can I display a counter that counts the number of times a file is downloaded? I've seen it before. "Downloaded 450 times". Thanks.

回答1:

Don't let the user download a file directly, but trough a script like the following ...

<?php

   $file = $_REQUEST['file'];
   $dldir = "downloads/";

   if (
       (file_exists($dldir.$file) &&               // file exists
       (strpos($file, "../") === false) &&  // prevent an attacker from switching to a parent directory
      ) {

       header('Content-type: '.mime_content_type($dldir.file));
       header("Content-Transfer-Encoding: binary");
       header("Content-Length: " . filesize($dldir.$file) ."; "); 
       header('Content-Disposition: attachment; filename="'.$file.'"');

       echo file_get_contents($dldir.$file);

       /** Update the counter here, e.g. by using mysql **/
   } else {
       die("File not found");
   }

?>

回答2:

If you want to do it with PHP, you need to control the download in a PHP script. Basically it comes down to the following two lines of pseudo-code:

set_number_of_downloads(get_number_of_downloads() + 1);
readfile($file_being_downloaded);

回答3:

There you go. Also, if you prefer using MySQL for persistence, there's this solution.

回答4:

On Apache you could have mod_rewrite update a database when the file is requested. This has the advantage of speed in sending (sendfile can be used), and you don't have to change your URLs or directory structure.

#!/usr/bin/perl
$| = 1;
$dbh = DBI->connect("dbi:mysql:database=; host=localhost; user=; password=")
or die "Connecting from PHP to MySQL database failed: $DBI::errstr";
while (<STDIN>) {
    $dbh->query(... update database ...);
    print $_;
}

http://httpd.apache.org/docs/2.2/mod/mod_rewrite.html#rewriteengine