Resumable PHP Upload (3)

<?php
    set_time_limit(0);
    header('Content-Type: text/html; charset=utf-8');

    if ( $temp_file_handle = fopen($_FILES['upload_file']['tmp_name'], "r") )
    {
            $file_name   = 'D:\xampp\htdocs\_tests\resume\final-file.bin';
        $file_handle = fopen($file_name, "a");

        while ( $data_chunk = fread($temp_file_handle, 4096) )
        {
            $length_chunk = strlen($data_chunk);
            fwrite( $file_handle, $data_chunk, $length_chunk );
        }

        fclose($file_handle);
        fclose($temp_file_handle);
    }
?>