PDF not downloading when file is called - php

Question

I have a database that is storing all my pdf files for a website. The table has columns for the library_item_id, filename(name of the file), mime_type, File size, file_item(the Blob) and I have a php file called download.php. This file is supposed to download the correct file from the database when they user clicks the link. But when the file is downloaded and clicked to open I get Adobe saying it cannot open the pdf. Saying its not decoded correctly. Here is my download.php file:
require_once("scripts/connection.php");
if(isset($_GET["id"])){
$fid = $_GET["id"];
}
else{
header("Location: literature.php");
}
$sql= "SELECT filename, mime_type, file_item FROM library_items WHERE library_item_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param('s', $fid);
$stmt->execute();
$stmt->bind_result($filename, $mime, $file_item);
while($stmt->fetch()){
$file_name = $filename;
$mime_type = $mime;
$file = $file_item;
}
header("Content-length: ".strlen($file));
header("Content-type: $mime_type");
header("Content-disposition: download; filename=$file_name");
echo $file;
mysqli_close($conn);
I have tried everything I could think of including add the obj_flush() commands and all that it still gives me the same error. What am I doing wrong on this?
Here is the edit for the code inserting the file into the database.
session_start();
$display = trim($_POST["file-display-name"]);
$company = trim($_POST["companies"]);
$lib_cat = trim($_POST["library-cats"]);
if(empty($display) || empty($company) || empty($lib_cat)){
$_SESSION["errormsg"] = "Required information is missing please fill out all required fields.";
header("Location: ../library.php");
}
else{
$file_name = $_FILES['library-file']['name'];
$tmp_name = $_FILES['library-file']['tmp_name'];
$file_size = $_FILES['library-file']['size'];
$file_type = $_FILES['library-file']['type'];
$fp = fopen($tmp_name, 'r');
$content = fread($fp, filesize($tmp_name));
$content = addslashes($content);
fclose($fp);
if(!get_magic_quotes_gpc()){
$file_name = addslashes($file_name);
}
if(empty($content)){
$_SESSION["errormsg"] = "Required information is missing please fill out all required fields.";
header("Location: ../library.php");
}
else{
require_once("connection.php");
// Insert the logo into the companies photo table
$sql = "INSERT INTO library_items(filename, mime_type, file_size, file_item, display_name, company_id, library_category_id) VALUES(?,?,?,?,?,?,?)";
$stmt = $conn->prepare($sql);
$stmt->bind_param('sssssss', $file_name, $file_type, $file_size, $content, $display, $company, $lib_cat);
if(!$stmt->execute()){
$_SESSION["errormsg"] = "Failed to add library item: ".mysqli_error();
header("Location: ../library.php");
}
}
unset($_SESSION["errormsg"]);
$_SESSION["successmsg"] = "Library Item successfully added into the database.";
header("Location: ../library.php");
}
UPDATE:
I now have the file downloading and attempting to display once the downloaded file is double clicked to open. It is telling me there is an invalid colorSpace. From what I can tell this is a problem when the file is uploaded into the database. From my upload file posted is there anything I am not doing correctly?

Answer 1

You need following changes. In the insert file
Instead of
$content = addslashes($content);
use
$content = base64_encode($content);
So while downloading, decode it.
$file = base64_decode($file_item);
Replace the following code
header("Content-type: '".$mime_type."'");
header("Content-Disposition: inline; filename='".$file_name."'");
header('Content-Transfer-Encoding: binary');
header('Accept-Ranges: bytes');
readfile($file);
with
header("Content-length: ".strlen($file));
header("Content-type: $mime_type");
header("Content-disposition: download; filename=$file_name");
echo $file;

Answer 2

check if size of downloaded file is correct (matches size of file in database). If it is, you should be debugging the part where the file is inserted into database. If not - check if anything gets printed out before sending file to browser - maybe scripts/connection.php prints something like empty line, error message or BOM?
If you can't find it, try turning output buffering on and call ob_clean() before sending file.
Sorry for my english, I hope it's understandable.