xdr_create(3N)                                               xdr_create(3N)


   NAME
         xdr_create:   xdr_destroy, xdrmem_create, xdrrec_create,
         xdrstdio_create - library routines for external data representation
         stream creation

   DESCRIPTION
         XDR library routines allow C programmers to describe arbitrary data
         structures in a machine-independent fashion.  Protocols such as
         remote procedure calls (RPC) use these routines to describe the
         format of the data.

         These routines deal with the creation of XDR streams.  XDR streams
         have to be created before any data can be translated into XDR format.

      Routines
         See rpc(3N) for the definition of the XDR, CLIENT, and SVCXPRT data
         structures.

         #include <rpc/xdr.h>

         void
         xdr_destroy(XDR *xdrs);

               A macro that invokes the destroy routine associated with the
               XDR stream, xdrs.  Destruction usually involves freeing private
               data structures associated with the stream.  Using xdrs after
               invoking xdr_destroy is undefined.

         void
         xdrmem_create(XDR *xdrs, const caddr_t addr,
               const u_int size, const enum xdr_op op);

               This routine initializes the XDR stream object pointed to by
               xdrs.  The stream's data is written to, or read from, a chunk
               of memory at location addr whose length is no more than size
               bytes long.  The op determines the direction of the XDR stream
               (either XDR_ENCODE, XDR_DECODE, or XDR_FREE).

         void
         xdrrec_create(XDR *xdrs, const u_int sendsz,
               const u_int recvsz, const caddr_t handle,
               const int (*readit)(const void *, char *, const int),
               const int (*writeit)(const void *, const char *, const int));

               This routine initializes the XDR stream object pointed to by
               xdrs.  The stream's data is written to a buffer of size sendsz;
               a value of 0 indicates the system should use a suitable
               default.  The stream's data is read from a buffer of size
               recvsz; it too can be set to a suitable default by passing a 0
               value.  When a stream's output buffer is full, writeit is
               called.  Similarly, when a stream's input buffer is empty,


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   xdr_create(3N)                                               xdr_create(3N)


               readit is called.  The behavior of these two routines is
               similar to the system calls read and write [see read(2) and
               write(2), respectively], except that handle (CLIENT, or
               SVCXPRT) is passed to the former routines as the first
               parameter instead of a file descriptor.  Note:  the XDR
               stream's op field must be set by the caller.

               Warning:  this XDR stream implements an intermediate record
               stream.  Therefore there are additional bytes in the stream to
               provide record boundary information.

         void
         xdrstdio_create(XDR *xdrs, FILE *file, const enum xdr_op op);

               This routine initializes the XDR stream object pointed to by
               xdrs.  The XDR stream data is written to, or read from, the
               standard I/O stream file.  The parameter op determines the
               direction of the XDR stream (either XDR_ENCODE, XDR_DECODE, or
               XDR_FREE).

               Warning:  the destroy routine associated with such XDR streams
               calls fflush on the file stream, but never fclose [see
               fclose(3S)].

   SEE ALSO
         fclose(3S), read(2), rpc(3N), write(2), xdr_admin(3N),
         xdr_complex(3N), xdr_simple(3N).


























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