VMS Help TCPIP Services, Programming Interfaces, RPC Server Routines, svc_getreqset, Example  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  #define MAXSOCK 10
       int readfds[ MAXSOCK+1],    /* sockets to select from*/
           i, j;
       for(i = 0, j = 0; i << MAXSOCK; i++)
            if((svc_fdset[i].sockname != 0) && (svc_
 fdset[i].sockname != -1))
                 readfds[j++] = svc_fdset[i].sockname;
       readfds[j] = 0;                 /* list of sockets ends with a zero */
       switch(select(0, readfds, 0, 0, 0))
       {
         case -1:      /* an error happened */
         case 0:       /* time out */
              break;
         default:      /* 1 or more sockets ready for reading */
              errno = 0;
              svc_getreqset(readfds);
              if( errno == ENETDOWN || errno == ENOTCONN)
              sys$exit( SS$_THIRDPARTY);
       }