At times we might want to give files for users to download. Also you wouldn't want to have the file storage location in a public access folder. To achieve these, you can store the file in an internal folder which is not accesible to public via a URL, and force the file to be downloaded using php header.

 The following code illustrates this method. Save this as download.php and pass the file as a parameter to it. 

<?
        //Get the file name passed to the script
        $filename = $_GET['dl'];
        
        //Absolute path the the file to be downloaded
        $dlfile = "/var/www/files/".$filename;
        
        // open the file and read it to a string
        $file_from   = fopen($dlfile,"r");
    $i           = 0;
    $data        = "";
    while ( $row = fread($file_from,filesize($dlfile)) ) {
      ++$i;
      $data .= $row;
    }
    fclose($file_from);
    
    /*
    By using the header option we tell the browser that the file format is not
    something which it can open. In the second line we are specifying the default file name.
    */
    header("Content-type: application/octet-stream");
    header("Content-Disposition: attachment; filename="".$filename."";");
    header("Content-Transfer-Encoding: binary");
    header("Cache-Control: cache, must-revalidate");
    header("Pragma: public");
    header("Expires: 0");
    
    /* We are storing the data and sending it to the client machine through the file download.*/
    echo $data;
    exit();
?>