Turning a html input value into a $variable for a download function

Question

This site has been immenselly helpful to me so far, but it seems I've finally come up against a problem. The question how to put a variable in a html input has been asked and awnsered before, but there's an issue I just can't seem to get to work.

<?php
if(isset($_POST['file_name'])){
    $file = $_POST['file_name'];
    header('Content-Disposition: attachment; filename="'.$file.'"');
    readfile('uploads/'.$file);
    exit();
}
?>
<form action="force_download.php" method="post" name="downloadform">
  <input name= "file_name" type="hidden" value="test.txt" />
  <input type="submit" value="Download">
</form>

The above code is being used to download the the text file "test.txt" One of many text files in my upload folder. My issue? How do I turn the value test.txt into a variable? A previous awnser I've read would be this:

<input type="hidden" name="file_name" value="<?php echo htmlspecialchars($file); ?>" />

The problem is that when I do that, it downloads force_download.php instead of any of my files.

I only started coding a few days ago, so yeah... sorry for the newbie question.

Answer 1

Here is one suggestion, you might need to do some ajustments.

In the file calling this one you posted the code to:
(if I understood good: intranet.php)

<form action="force_download.php" method="post" name="downloadform">
<?php
$path = "./filesfolder/"; // this you need to change to your files folder

function createDir($path)
{   
    if ($handle = opendir($path)) 
    {
        while (false !== ($file = readdir($handle))) 
        {
            if (is_dir($path.$file) && $file != '.' && $file !='..')
                printSubDir($file, $path, $queue);
            else if ($file != '.' && $file !='..')
                $queue[] = $file;
        }
        printQueue($queue, $path);
    }
}
function printQueue($queue, $path)
{
    foreach ($queue as $file) 
    {
        printFile($file, $path);
    } 
}
function printFile($file, $path)
{
    if ($file=="thumbs.db") {echo "";}
    else 
    {
    echo "
<input name= \"".$file."\" type=\"hidden\" value=\"".$file."\" />";
    }
}
createDir($path);
?>
<input type="submit" value="Download">
</form>

This will generate the html for all files it finds, with the clickable link to each file. In this case you don't need the in the file you posted (which I think is force_download.php)

Answer 2

Here a function I wrote and use for a while, please consider adding the a routine for the correct contect-type as well:

function downloadFile($fullPathToFile, $renameFile=''){
        if(is_file($fullPathToFile)){
            $path_parts = pathinfo($fullPathToFile);
            $dirname =  $path_parts['dirname'];
            $basename = $path_parts['basename'];
            $extension = $path_parts['extension'];
            $filename = $path_parts['filename'];
            $filesize = filesize($fullPathToFile);

            if(!empty($renameFile)){
                $extension = preg_match("/\.([^\.]+)$/", $renameFile, $matches);
                $extension = preg_replace('/\./', '', $matches[0]) ;
            } 
                    /*Change the following one line to type of files or comment out*/
            header("Content-Type: text/plain"); 
            header ("Content-Length: " . $filesize );
            header("Pragma: ");
            header("Cache-Control: ");
            if($renameFile){
                header("Content-Disposition: attachment; filename=\"$renameFile\"");
            }else{
                header("Content-Disposition: attachment; filename=\"$basename\"");
            }
            ob_clean();
            flush();
            readfile($dirname.'/'.$basename);
            die();
        }
        else {
            echo 'no such file or directory';
        }
}