Return_Values

   0                  Successful completion.
   -1                 Indicates an error. The function sets errno to
                      one of the following values:

                      o  E2BIG - The value of nsops is greater than
                         the system-imposed maximum.

                      o  EACCES - Operation permission is denied to
                         the calling process.

                      o  EAGAIN - The operation would result in
                         suspension of the calling process but (sem_
                         flg &IPC_NOWAIT) is nonzero.

                      o  EFAULT - The arguments passed to the
                         function are not accessible.

                      o  EFBIG - The value of sem_num is less than
                         0 or greater than or equal to the number
                         of semaphores in the set associated with
                         semid.

                      o  EIDRM - The semaphore identifier semid is
                         removed from the system.

                      o  EINVAL - The value of semid is not a valid
                         semaphore identifier, or the number of
                         individual semaphores for which the calling
                         process requests a SEM_UNDO would exceed
                         the system-imposed limit.

                      o  EVMSERR - OpenVMS specific nontranslatable
                         error code.