Get file size from multipart form upload Content-Length header

Question

So, I\'m uploading a file, and then downloading it... but the Content-Length in the upload headers do not match the file size. I\'m guessing there is some other data involve

Answer 1

I think that each section of the multipart/form-data request counts toward the overall size of the main Content-Length header.

Found this as a reference: http://chxo.com/be2/20050724_93bf.html

So, perhaps after your headers, you might have:

----WebKitFormBoundaryeoFyqD4zr6smwYDG

Content-Disposition: form-data; name="file"; filename="testfile-downloaded.zip"; size=<file size could be here>
Content-Length: <file size could also be here>
<some other content headers>

<file data>

----WebKitFormBoundaryeoFyqD4zr6smwYDG

All of which would count toward the Content-Length size.

EDIT

Just realized I didn't answer your question. Not sure how to pull out the file size from the file section of the request. Sorry!

Answer 2

The data you received is always bigger than you file. Just scan the "boundary" value for the starting and ending of the file.

The reference: How does HTTP file upload work?