PHP: Anatomy of a file upload
All details are on the PHP site (but just the highlights because I seem to need it a lot):
$_FILES['userfile']['name']
The original name of the file on the client machine.
$_FILES['userfile']['type']
The mime type of the file, if the browser provided this information. An example would be “image/gif”.
$_FILES['userfile']['size']
The size, in bytes, of the uploaded file.
$_FILES['userfile']['tmp_name']
The temporary filename of the file in which the uploaded file was stored on the server.
$_FILES['userfile']['error']
The error code associated with this file upload. ['error'] was added in PHP 4.2.0