Obtains the total number of bytes either input from or output to the open binary stream Stream and unifies it with Count.
A valid open binary stream.
The resulting byte count of the stream.
A freshly opened stream has a byte count of 0. When a byte is input from or output to a Prolog stream, the byte count of the Prolog stream is increased by one.
The count is reset by
Stream errors (see ref-iou-sfh-est).