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.