PHP - File download through fread preserving last modification time

Question

The following script (just the relevant part) that let me download a file:

if ($file = fopen($file, 'r'))
{
    if(isset($_SERVER['HTTP_RANGE']))
    {
        fseek($file, $range);
    } 
    while(!feof($file) && 
        (!connection_aborted()) && 
        ($bytes_send<$new_length))
    {
        $buffer = fread($file, $chunksize);
        print($buffer); //echo($buffer); // is also possible
        flush();
        $bytes_send += strlen($buffer);
    }
    fclose($file);
}

Doing this, the downloaded file will show the actual time as its creation time.

I would like to know how to preserve the last modification file that it has on the server.

I know I can get the info with filemtime but I don't know how to use it in combination with the script above.

Answer 1

Before sending any output, do

header("Last-Modified: " . gmdate("D, d M Y H:i:s", filemtime($file)) . " GMT");

I don't think this will cause a web browser to save the file locally with that modification time. I think you need to use some type of archive format for that, like zip.