Shell Programming and Scripting

<?php
ob_start();
$company =$_GET['company'];
if(isset($_GET['id']))
{
  $id = intval($_GET['id']);
  if($id <= 0)
  {
    die('The ID is invalid!');
  }
  else
  {
    $dbLink = new mysqli('localhost', 'sqldata', 'sqldata', 'balhaf');
    if(mysqli_connect_errno())
    {
      die("MySQL connection failed: ". mysqli_connect_error());
    }
    $query = "SELECT mime, name, size, data FROM $company WHERE id = $id";
    $result = $dbLink->query($query);
    if($result)
    {
      if($result->num_rows == 1) {
        $row = mysqli_fetch_assoc($result);
        $size = $row['size'];
        $filename = $row['name'];
        $data = $row['data'];
        $mime = $row['mime'];
        ini_get('zlib.output_compression');
        ini_set('zlib.output_compression', 'Off');
        header('Content-Type: application/pdf');
        while (@ob_end_clean());
        header('Content-Disposition: attachment; filename='.($filename));
        header('Content-Length:'.($size));
        echo $data;
        exit();
      }
      else
      {
        echo 'Error! No image exists with that ID.';
      }
      mysqli_free_result($result);
    }
    else
    {
      echo "Error! Query failed: <pre>{$dbLink->error}</pre>";
    }
    mysqli_close($dbLink);
  }
}
else
{
  echo 'Error! No ID was passed.';
}
?>