Why might a file only be partially uploaded?

Question

Why might a file only be partially uploaded?

I am improving error-handling in my PHP file upload script and am trying to figure out how to handle UPLOAD_ERR_PARTIAL properly.

Should I prompt the user to try uploading the file again, or should I inform them that there is a more severe problem which is preventing them from uploading a possibly legitimate file?

Thanks!

Answer 1

Why might a file only be partially uploaded?

This is usually caused by the user canceling the upload.

Should I prompt the user to try uploading the file again, or should I inform them that there is a more severe problem which is preventing them from uploading a possibly legitimate file?

You should prompt them to try again and if problems continue to contact the site owners, including as much detail as possible.

Answer 2

UPLOAD_ERR_PARTIAL is given when the mime boundary is not found after the file data. A possibly cause for this is that the upload was cancelled by the user (pressed ESC, etc).

I think it's enough to inform the user that the file is only partially uploaded and a retry will fix the problem.

Answer 3

Well, the file upload could be interrupted by:

Out of space in destination

Connection interruption

Damage file

Wrong name

Wrong extension

etc...

The best you can do is to verify and protect the upload process with does verifications before actually send the file to the server...

The first time I've made a file upload script, I used 1 line of code, now, the same script seems like a web page ;)

EDITED (example for controlling extension and file size):

if ((

($file_up["type"] == "image/gif") ||

($file_up["type"] == "image/jpeg") ||

($file_up["type"] == "image/jpg") ||

($file_up["type"] == "image/pjpeg") ||

($file_up["type"] == "image/bmp") ||

($file_up["type"] == "image/tiff") ||

($file_up["type"] == "image/png")) &&

($file_up["size"] < 1050000))

{

    code if all ok...


}