SP_flush_output()     #include <sicstus/sicstus.h>
     
     spio_t_error_code
     SP_flush_output(
       SP_stream *stream,
       spio_t_bits flush_options);
   Ensure that all buffered data reaches its destination.
SP_FLUSH_OUTPUT_OPTION_NONBLOCKINGSPIO_E_WOULD_BLOCK code.
          Can return SPIO_E_NOT_SUPPORTED if the stream cannot support
non-blocking flush.
          
SP_FLUSH_OUTPUT_OPTION_AUTOFLUSHOn success, all buffered data should have been written and
SPIO_S_NOERR or some other success code returned.
   
On failure, returns a SPIO error code. Error codes with special meaning
for SP_flush_output():
     
SPIO_E_END_OF_FILESPIO_E_WOULD_BLOCKSP_FLUSH_OUTPUT_OPTION_NONBLOCKING was set but the operation
would block.
     SPIO_E_NOT_SUPPORTEDSP_FLUSH_OUTPUT_OPTION_NONBLOCKING,  was passed. 
Other error codes may also be returned.