now -F supports 'filename=blabla' for parts that upload a file, to set the

filename field of that part. A typical example line could look like:

-F 'name=@filename;filename=/dev/null'

This can be combined with type= too, in a manner similar to:

-F "file=@log/test39.txt;filename=fakerfile;type=moo/foobar"

Enjoy.