read, write,
append, update or insert. The
resulting
Stream must be closed using close/1.
When opened for
update or insert, the current location is
initialized at the start of the data and can be modified using seek/4
or
set_stream_position/2.
In update mode, existing content is replaced, while the
size is enlarged after hitting the end of the data. In insert
mode, the new data is inserted at the current point.