On a custom form I have a file field. Having chosen the file and clicked Submit, I'm trying to find how to access and read the uploaded file. I have no need to move or save it, I simply need to open it and use fgetcsv on it.
I've looked at the online examples I can find, but they seem to either deal with managed files or moving and saving unmanaged ones. The Examples module seems to only have a placeholder with regards to the file example.