get_byte/[1,2]
ISOget_byte(-Byte)
get_byte(+Stream, -Byte)
Unifies Byte with the next byte from Stream or with -1 if there are no more bytes.
stream_object, must be ground
valid input binary stream, defaults to the current input stream.
byte or -1
Stream errors (see ref-iou-sfh-est), plus:
type_error
Byte is an invalid byte.
permission_error
Trying to read beyond end of Stream