xdr_complex(3N)                  UNIX System V                  xdr_complex(3N)


NAME
      xdrcomplex:   xdrarray, xdrbytes, xdropaque, xdrpointer,
      xdrreference, xdrstring, xdrunion, xdrvector, xdrwrapstring -
      library routines for external data representation

DESCRIPTION
      XDR library routines allow C programmers to describe complex 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 are the XDR library routines for complex data
      structures.  They require the creation of XDR stream [see
      xdrcreate(3N)].

   Routines
      See rpc(3N) for the definition of the XDR data structure.

      #include <rpc/xdr.h>

      boolt
      xdrarray(XDR *xdrs, caddrt *arrp, uint *sizep,
            const uint maxsize, const uint elsize,
            const xdrproct elproc);

            xdrarray translates between variable-length arrays and their
            corresponding external representations.  The parameter arrp is the
            address of the pointer to the array, while sizep is the address of
            the element count of the array; this element count cannot exceed
            maxsize.  The parameter elsize is the sizeof each of the array's
            elements, and elproc is an XDR routine that translates between the
            array elements' C form and their external representation.  This
            routine returns 1 if it succeeds, 0 otherwise.

      boolt
      xdrbytes(XDR *xdrs, char **sp, uint *sizep,
            const uint maxsize);

            xdrbytes translates between counted byte strings and their
            external representations.  The parameter sp is the address of the
            string pointer.  The length of the string is located at address
            sizep; strings cannot be longer than maxsize.  This routine returns
            1 if it succeeds, 0 otherwise.

      boolt
      xdropaque(XDR *xdrs, caddrt cp, const uint cnt);

            xdropaque translates between fixed size opaque data and its
            external representation.  The parameter cp is the address of the
            opaque object, and cnt is its size in bytes.  This routine returns
            1 if it succeeds, 0 otherwise.





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xdr_complex(3N)                  UNIX System V                  xdr_complex(3N)


      boolt
      xdrpointer(XDR *xdrs, char **objpp, uint objsize,
            const xdrproct xdrobj);

            Like xdrreference except that it serializes NULL pointers, whereas
            xdrreference does not.  Thus, xdrpointer can represent recursive
            data structures, such as binary trees or linked lists.

      boolt
      xdrreference(XDR *xdrs, caddrt *pp, uint size,
            const xdrproct proc);

            xdrreference provides pointer chasing within structures.  The
            parameter pp is the address of the pointer; size is the sizeof the
            structure that *pp points to; and proc is an XDR procedure that
            translates the structure between its C form and its external
            representation.  This routine returns 1 if it succeeds, 0
            otherwise.

            Note:  this routine does not understand NULL pointers.  Use
            xdrpointer instead.

      boolt
      xdrstring(XDR *xdrs, char **sp, const uint maxsize);

            xdrstring translates between C strings and their corresponding
            external representations.  Strings cannot be longer than maxsize.
            Note:  sp is the address of the string's pointer.  This routine
            returns 1 if it succeeds, 0 otherwise.

      boolt
      xdrunion(XDR *xdrs, enumt *dscmp, char *unp,
            const struct xdrdiscrim *choices,
            const boolt (*defaultarm)(const XDR *, const char *,
                  const int));

            xdrunion translates between a discriminated C union and its
            corresponding external representation.  It first translates the
            discriminant of the union located at dscmp.  This discriminant is
            always an enumt.  Next the union located at unp is translated.
            The parameter choices is a pointer to an array of xdrdiscrim
            structures.  Each structure contains an ordered pair of [value,
            proc].  If the union's discriminant is equal to the associated
            value, then the proc is called to translate the union.  The end of
            the xdrdiscrim structure array is denoted by a routine of value
            NULL.  If the discriminant is not found in the choices array, then
            the defaultarm procedure is called (if it is not NULL).  Returns 1
            if it succeeds, 0 otherwise.

      boolt
      xdrvector(XDR *xdrs, char *arrp, const uint size,
            const uint elsize, const xdrproct elproc);


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xdr_complex(3N)                  UNIX System V                  xdr_complex(3N)


            xdrvector translates between fixed-length arrays and their
            corresponding external representations.  The parameter arrp is the
            address of the pointer to the array, while size is is the element
            count of the array.  The parameter elsize is the sizeof each of the
            array's elements, and elproc is an XDR routine that translates
            between the array elements' C form and their external
            representation.  This routine returns 1 if it succeeds, 0
            otherwise.

      boolt
      xdrwrapstring(XDR *xdrs, char **sp);

            A routine that calls xdrstring(xdrs, sp, maxuint); where maxuint
            is the maximum value of an unsigned integer.

            Many routines, such as xdrarray, xdrpointer and xdrvector take a
            function pointer of type xdrproct, which takes two arguments.
            xdrstring, one of the most frequently used routines, requires
            three arguments, while xdrwrapstring only requires two.  For these
            routines, xdrwrapstring is desirable.  This routine returns 1 if
            it succeeds, 0 otherwise.

SEE ALSO
      rpc(3N), xdradmin(3N), xdrcreate(3N), xdrsimple(3N)






























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