stream_code/2stream_code(-Stream, +CStream)
   
stream_code(+Stream, -CStream)
   
Converts between Prolog representation, Stream, and C representation, CStream, of a stream.
A valid Prolog stream.
     
Representing an SP_stream * pointer. 
At least one argument must be ground. 
stream_code/2 is used when there are input/output related operations
performed on the same stream in both Prolog code and foreign code. 
The CStream value can be used as the stream argument to
any of the SP_* functions taking a stream argument.
instantiation_errortype_errorexistence_error