Updated: 2022/Sep/29

Please read Privacy Policy. It's for your privacy.


XDR(3)                     Library Functions Manual                     XDR(3)

NAME
     xdr, xdr_array, xdr_bool, xdr_bytes, xdr_char, xdr_destroy, xdr_double,
     xdr_enum, xdr_float, xdr_free, xdr_getpos, xdr_hyper, xdr_inline,
     xdr_int, xdr_long, xdr_longlong_t, xdrmem_create, xdr_opaque,
     xdr_pointer, xdrrec_create, xdrrec_endofrecord, xdrrec_eof,
     xdrrec_skiprecord, xdr_reference, xdr_setpos, xdr_short, xdr_sizeof,
     xdrstdio_create, xdr_string, xdr_u_char, xdr_u_hyper, xdr_u_long,
     xdr_u_longlong_t, xdr_u_short, xdr_union, xdr_vector, xdr_void,
     xdr_wrapstring - library routines for external data representation

SYNOPSIS
     int
     xdr_array(XDR *xdrs, char **arrp, u_int *sizep, u_int maxsize,
         u_int elsize, xdrproc_t elproc);

     int
     xdr_bool(XDR *xdrs, bool_t *bp);

     int
     xdr_bytes(XDR *xdrs, char **sp, u_int *sizep, u_int maxsize);

     int
     xdr_char(XDR *xdrs, char *cp);

     void
     xdr_destroy(XDR *xdrs);

     int
     xdr_double(XDR *xdrs, double *dp);

     int
     xdr_enum(XDR *xdrs, enum_t *ep);

     int
     xdr_float(XDR *xdrs, float *fp);

     void
     xdr_free(xdrproc_t proc, char *objp);

     u_int
     xdr_getpos(XDR *xdrs);

     int
     xdr_hyper(XDR *xdrs, longlong_t *llp);

     long *
     xdr_inline(XDR *xdrs, int len);

     int
     xdr_int(XDR *xdrs, int *ip);

     int
     xdr_long(XDR *xdrs, long *lp);

     int
     xdr_longlong_t(XDR *xdrs, longlong_t *llp);

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

     int
     xdr_opaque(XDR *xdrs, char *cp, u_int cnt);

     int
     xdr_pointer(XDR *xdrs, char **objpp, u_int objsize, xdrproc_t xdrobj);

     void
     xdrrec_create(XDR *xdrs, u_int sendsize, u_int recvsize, char *handle,
         int (*readit)(), int (*writeit)());

     int
     xdrrec_endofrecord(XDR *xdrs, int sendnow);

     int
     xdrrec_eof(XDR *xdrs);

     int
     xdrrec_skiprecord(XDR *xdrs);

     int
     xdr_reference(XDR *xdrs, char **pp, u_int size, xdrproc_t proc);

     int
     xdr_setpos(XDR *xdrs, u_int pos);

     int
     xdr_short(XDR *xdrs, short *sp);

     nsigned long
     xdr_sizeof(xdrproc_t func, void *data);

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

     int
     xdr_string(XDR *xdrs, char **sp, u_int maxsize);

     int
     xdr_u_char(XDR *xdrs, unsigned char *ucp);

     int
     xdr_u_hyper(XDR *xdrs, u_longlong_t *ullp);

     int
     xdr_u_int(XDR *xdrs, unsigned *up);

     int
     xdr_u_long(XDR *xdrs, unsigned long *ulp);

     int
     xdr_u_longlong_t(XDR *xdrs, u_longlong_t *ullp);

     int
     xdr_u_short(XDR *xdrs, unsigned short *usp);

     int
     xdr_union(XDR *xdrs, int *dscmp, char *unp, struct xdr_discrim *choices,
         bool_t (*defaultarm)());

     int
     xdr_vector(XDR *xdrs, char *arrp, u_int size, u_int elsize,
         xdrproc_t elproc);

     int
     xdr_void(void);

     int
     xdr_wrapstring(XDR *xdrs, char **sp);

DESCRIPTION
     These routines allow C programmers to describe arbitrary data structures
     in a machine-independent fashion.  Data for remote procedure calls are
     transmitted using these routines.

     xdr_array()
          A filter primitive that 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 filter that translates
          between the array elements' C form, and their external
          representation.  This routine returns one if it succeeds, zero
          otherwise.

     xdr_bool()
          A filter primitive that translates between booleans (C integers) and
          their external representations.  When encoding data, this filter
          produces values of either one or zero.  This routine returns one if
          it succeeds, zero otherwise.

     xdr_bytes()
          A filter primitive that 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
          one if it succeeds, zero otherwise.

     xdr_char()
          A filter primitive that translates between C characters and their
          external representations.  This routine returns one if it succeeds,
          zero otherwise.  Note: encoded characters are not packed, and occupy
          4 bytes each.  For arrays of characters, it is worthwhile to
          consider xdr_bytes(), xdr_opaque() or xdr_string().

     xdr_destroy()
          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.

     xdr_double()
          A filter primitive that translates between C double precision
          numbers and their external representations.  This routine returns
          one if it succeeds, zero otherwise.

     xdr_enum()
          A filter primitive that translates between C enums (actually
          integers) and their external representations.  This routine returns
          one if it succeeds, zero otherwise.

     xdr_float()
          A filter primitive that translates between C floats and their
          external representations.  This routine returns one if it succeeds,
          zero otherwise.

     xdr_free()
          Generic freeing routine.  The first argument is the XDR routine for
          the object being freed.  The second argument is a pointer to the
          object itself.  Note: the pointer passed to this routine is not
          freed, but what it points to is freed (recursively).

     xdr_getpos()
          A macro that invokes the get-position routine associated with the
          XDR stream, xdrs.  The routine returns an unsigned integer, which
          indicates the position of the XDR byte stream.  A desirable feature
          of XDR streams is that simple arithmetic works with this number,
          although the XDR stream instances need not guarantee this.

     xdr_hyper()
          A filter primitive that translates between ANSI C long long integers
          and their external representations.  This routine returns one if it
          succeeds, zero otherwise.

     xdr_inline()
          A macro that invokes the in-line routine associated with the XDR
          stream, xdrs.  The routine returns a pointer to a contiguous piece
          of the stream's buffer; len is the byte length of the desired
          buffer.  Note: pointer is cast to long *.

          Warning: xdr_inline() may return NULL if it cannot allocate a
          contiguous piece of a buffer.  Therefore the behavior may vary among
          stream instances; it exists for the sake of efficiency.

     xdr_int()
          A filter primitive that translates between C integers and their
          external representations.  This routine returns one if it succeeds,
          zero otherwise.

     xdr_long()
          A filter primitive that translates between C long integers and their
          external representations.  This routine returns one if it succeeds,
          zero otherwise.

     xdr_longlong_t()
          A filter primitive that translates between ANSI C long long integers
          and their external representations.  This routine returns one if it
          succeeds, zero otherwise.

     xdrmem_create()
          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).

     xdr_opaque()
          A filter primitive that 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 one if it succeeds, zero otherwise.

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

     xdrrec_create()
          This routine initializes the XDR stream object pointed to by xdrs.
          The stream's data is written to a buffer of size sendsize; a value
          of zero indicates the system should use a suitable default.  The
          stream's data is read from a buffer of size recvsize; it too can be
          set to a suitable default by passing a zero value.  When a stream's
          output buffer is full, writeit is called.  Similarly, when a
          stream's input buffer is empty, readit is called.  The behavior of
          these two routines is similar to the system calls read(2) and
          write(2), except that handle is passed to the former routines as the
          first parameter.  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.

     xdrrec_endofrecord()
          This routine can be invoked only on streams created by
          xdrrec_create().  The data in the output buffer is marked as a
          completed record, and the output buffer is optionally written out if
          sendnow is non-zero.  This routine returns one if it succeeds, zero
          otherwise.

     xdrrec_eof()
          This routine can be invoked only on streams created by
          xdrrec_create().  After consuming the rest of the current record in
          the stream, this routine returns one if the stream has no more
          input, zero otherwise.

     xdrrec_skiprecord()
          This routine can be invoked only on streams created by
          xdrrec_create().  It tells the XDR implementation that the rest of
          the current record in the stream's input buffer should be discarded.
          This routine returns one if it succeeds, zero otherwise.

     xdr_reference()
          A primitive that 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
          filters the structure between its C form and its external
          representation.  This routine returns one if it succeeds, zero
          otherwise.

          Warning: this routine does not understand NULL pointers.  Use
          xdr_pointer() instead.

     xdr_setpos()
          A macro that invokes the set position routine associated with the
          XDR stream xdrs.  The parameter pos is a position value obtained
          from xdr_getpos().  This routine returns one if the XDR stream could
          be repositioned, and zero otherwise.

          Warning: it is difficult to reposition some types of XDR streams, so
          this routine may fail with one type of stream and succeed with
          another.

     xdr_short()
          A filter primitive that translates between C short integers and
          their external representations.  This routine returns one if it
          succeeds, zero otherwise.

     xdr_sizeof()
          This routine returns the amount of memory required to encode data
          using filter func.

     xdrstdio_create()
          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(3) on the file stream, but never fclose(3).

     xdr_string()
          A filter primitive that 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 one if it succeeds, zero otherwise.

     xdr_u_char()
          A filter primitive that translates between unsigned C characters and
          their external representations.  This routine returns one if it
          succeeds, zero otherwise.

     xdr_u_hyper()
          A filter primitive that translates between unsigned ANSI C long long
          integers and their external representations.  This routine returns
          one if it succeeds, zero otherwise.

     xdr_u_int()
          A filter primitive that translates between C unsigned integers
           and their external representations.  This routine returns one if it
          succeeds, zero otherwise.

     xdr_u_long()
          A filter primitive that translates between C unsigned long integers
          and their external representations.  This routine returns one if it
          succeeds, zero otherwise.

     xdr_u_longlong_t()
          A filter primitive that translates between unsigned ANSI C long long
          integers and their external representations.  This routine returns
          one if it succeeds, zero otherwise.

     xdr_u_short()
          A filter primitive that translates between C unsigned short integers
          and their external representations.  This routine returns one if it
          succeeds, zero otherwise.

     xdr_union()
          A filter primitive that 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 enum_t.  Next the union located at unp is translated.
          The parameter choices is a pointer to an array of xdr_discrim()
          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 xdr_discrim() 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 one
          if it succeeds, zero otherwise.

     xdr_vector()
          A filter primitive that 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 the element
          count of the array.  The parameter elsize is the sizeof each of the
          array's elements, and elproc is an XDR filter that translates
          between the array elements' C form, and their external
          representation.  This routine returns one if it succeeds, zero
          otherwise.

     xdr_void()
          This routine always returns one.  It may be passed to RPC routines
          that require a function parameter, where nothing is to be done.

     xdr_wrapstring()
          A primitive that calls xdr_string(xdrs, sp, MAXUN.UNSIGNED); where
          MAXUN.UNSIGNED is the maximum value of an unsigned integer.
          xdr_wrapstring() is handy because the RPC package passes a maximum
          of two XDR routines as parameters, and xdr_string(), one of the most
          frequently used primitives, requires three.  Returns one if it
          succeeds, zero otherwise.

SEE ALSO
     rpc(3)

     The following manuals:

     eXternal Data Representation Standard: Protocol Specification.

     eXternal Data Representation: Sun Technical Notes.

     Sun Microsystems, Inc., USC-ISI, XDR: External Data Representation
     Standard, RFC 1014, USC-ISI, 1014.

NetBSD 10.99                     July 4, 2011                     NetBSD 10.99