0

I have the following simple webpage that works for uploading any file:

<html>
<head>
</head>
<body>
  <form action="upload_file.php" method="post" enctype="multipart/form-data">
    <input type="file" name="filefield" id="filefield"><br>
    <button type="submit">submit</button>
  </form>
</body>
</html>

And the following Ajax version which works with only very small files:

<html>
<head>
</head>
<body>
  <script>
    function postForm() {
      var xhttp = new XMLHttpRequest();
      var formData = new FormData();
      formData.append("filefield", document.getElementById("filefield").files[0]);
      xhttp.open("POST", "upload_file.php", true);
      xhttp.send(formData);
    }
  </script>
  <form>
    <input type="file" name="filefield" id="filefield"><br>
    <button onclick="postForm()">submit</button>
  </form>
</body>
</html>

I hven't checked exactly how big a file is too big, but a 100 KB file uploads successfully, while a 2 MB file fails. Wireshark shows that the browser just stops sending the file packets part way through, and sends a FIN flag. The server replies with HTTP status code 200 and PHP error 3 indicating that the file was only partially uploaded. Results are the same on recent versions of IE and Chrome.

Can someone explain why this is happening and what the solution is? Thanks.

D P
  • 41
  • 1
  • 4
  • This only occurs when you're at work? Maybe a proxy in between doesn't like large requests? – Halcyon Jun 06 '17 at 16:21
  • Check [PHP change the maximum upload file size](https://stackoverflow.com/questions/2184513/php-change-the-maximum-upload-file-size) – Joe Black Jun 06 '17 at 16:25
  • @Halcyon no it is happening on my home network too which is unrestricted, and also that would not explain why the HTML form post works, which is the same kind of large request. – D P Jun 06 '17 at 18:06
  • @Joe Black thanks, I already did that to avoid PHP error 1. But the error 3 and browser truncating the post is a separate issue. – D P Jun 06 '17 at 18:10
  • Try this solution: [php upload file error code 3](https://stackoverflow.com/questions/35006344/php-upload-file-error-code-3) – Joe Black Jun 06 '17 at 18:46
  • @Joe Black thanks for the suggestion, but I checked my PHP, and this is not the same as my case. It seems to be a client-side issue, because it happens even wih a totally different web server running on an embedded device. – D P Jun 06 '17 at 20:49

0 Answers0