Parameter values returned to the application

BUF

On input, a buffer to be filled by completion of the call. The length of BUF must be at least as long as the value of NBYTE.

ERRNO

A fullword binary field. If RETCODE is negative, the field contains an error number. See Return codes for information about ERRNO return codes.

RETCODE

A fullword binary field that returns one of the following values:

Value: Description
0: A 0 return code indicates that the connection is closed and no data is available.
>0: A positive value indicates the number of bytes copied into the buffer.
-1: Check ERRNO for an error code.