causes PL_release_stream() to print a message (SIO_WARN) or raise an exception (SIO_FERR).

int Sset_exception(IOSTREAM *s, term_t ex)

Associate a Prolog exception term with the stream or clear the associated exception if ex is 0 and set/clear the SIO_FERR condition on the stream. If an exception is assocated PL_release_stream() raises this exception.

12.9.5 Foreign stream encoding

IOSTREAM has a field encoding that is managed at initialization from SIO_TEXT. The available encodings are defined as a C enum as below.

typedef enum
{ ENC_UNKNOWN = 0,                      /* invalid/unknown */
  ENC_OCTET,                            /* raw 8 bit input */
  ENC_ASCII,                            /* US-ASCII (0..127) */
  ENC_ISO_LATIN_1,