VMS Help System Services, $GETDVIW  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Returns information about an I/O device; this information
    consists of primary and secondary device characteristics.

    The $GETDVIW service completes synchronously; that is, it returns
    to the caller with the requested information. Compaq recommends
    that you use an IOSB with this service. An IOSB prevents the
    service from completing prematurely. In addition, the IOSB
    contains additional status information.

    For asynchronous completion, use the Get Device/Volume
    Information ($GETDVI) service; $GETDVI returns to the caller
    after queuing the information request, without waiting for the
    information to be returned. In all other respects, $GETDVIW
    is identical to $GETDVI. For all other information about the
    $GETDVIW service, refer to the description of $GETDVI.

    Format

      SYS$GETDVIW  [efn] ,[chan] ,[devnam] ,itmlst [,iosb] [,astadr]

                   [,astprm] [,nullarg]

    C Prototype

      int sys$getdviw  (unsigned int efn, unsigned short int chan,

                       void *devnam, void *itmlst, struct _iosb

                       *iosb, void (*astadr)(__unknown_params), int

                       astprm, unsigned __int64 *nullarg);