XDR(3) | Library Functions Manual | XDR(3) |
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
, xdrstdio_create
,
xdr_string
, xdr_u_char
,
xdr_u_hyper
, xdr_u_int
,
xdr_u_long
,
xdr_u_longlong_t
,
xdr_u_short
, xdr_union
,
xdr_vector
, xdr_void
,
xdr_wrapstring
— library
routines for external data representation
Standard C Library (libc, -lc)
#include
<rpc/types.h>
#include <rpc/xdr.h>
See DESCRIPTION for function declarations.
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
(XDR
*xdrs, char **arrp, u_int
*sizep, u_int maxsize, u_int
elsize, xdrproc_t elproc);A filter primitive that translates between variable-length
arrays and their corresponding external representations. The
arrp argument 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 elsize argument
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
(XDR
*xdrs, bool_t *bp)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
(XDR
*xdrs, char **sp, u_int
*sizep, u_int maxsize)A filter primitive that translates between counted byte strings and their external representations. The sp argument 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
(XDR
*xdrs, char *cp)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
(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.
xdr_double
(XDR
*xdrs, double *dp)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
(XDR
*xdrs, enum_t *ep)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
(XDR
*xdrs, float *fp)A filter primitive that translates between C floats and their external representations. This routine returns one if it succeeds, zero otherwise.
xdr_free
(xdrproc_t
proc, void *objp)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
(XDR
*xdrs)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
(XDR
*xdrs, quad_t *llp)xdr_inline
(XDR
*xdrs, int len)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
(0) 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
(XDR
*xdrs, int *ip)A filter primitive that translates between C integers and their external representations. This routine returns one if it succeeds, zero otherwise.
xdr_long
(XDR
*xdrs, long *lp)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
(XDR
*xdrs, quad_t *llp)xdrmem_create
(XDR
*xdrs, char *addr, u_int
size, 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 argument determines the direction of the XDR
stream (either XDR_ENCODE
,
XDR_DECODE
, or
XDR_FREE
).
xdr_opaque
(XDR
*xdrs, char *cp, u_int
cnt)A filter primitive that translates between fixed size opaque data and its external representation. The cp argument 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
(XDR
*xdrs, char **objpp, u_int
objsize, xdrproc_t xdrobj)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
(XDR
*xdrs, u_int sendsize, u_int
recvsize, void *handle, int
(*readit)(), int (*writeit)());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 argument. 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
(XDR
*xdrs, int sendnow)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
(XDR
*xdrs)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
(XDR
*xdrs)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
(XDR
*xdrs, char **pp, u_int
size, xdrproc_t proc)A primitive that provides pointer chasing within structures.
The pp argument 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
(XDR
*xdrs, u_int pos)A macro that invokes the set position
routine associated with the XDR stream xdrs. The
pos argument 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
(XDR
*xdrs, short *sp)A filter primitive that translates between C short integers and their external representations. This routine returns one if it succeeds, zero otherwise.
#ifdef
_STDIO_H_
/* XDR using
stdio library */
xdrstdio_create
(XDR
*xdrs, FILE *file, enum xdr_op
op)#endif
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
op argument 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
(XDR
*xdrs, char **sp, u_int
maxsize)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
(XDR
*xdrs, unsigned char *ucp)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
(XDR
*xdrs, u_quad_t *ullp)xdr_u_int
(XDR
*xdrs, unsigned *up)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
(XDR
*xdrs, unsigned long *ulp)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
(XDR
*xdrs, u_quad_t *ullp)xdr_u_short
(XDR
*xdrs, unsigned short *usp)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
(XDR
*xdrs, enum_t *dscmp, char
*unp, const struct xdr_discrim *choices,
xdrproc_t defaultarm);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
choices argument 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
(XDR
*xdrs, char *arrp, u_int
size, u_int elsize, xdrproc_t
elproc);A filter primitive that translates between fixed-length arrays
and their corresponding external representations. The
arrp argument is the address of the pointer to the
array, while size is the element count of the
array. The elsize argument 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
(void)This routine always returns one. It may be passed to RPC routines that require a function argument, where nothing is to be done.
xdr_wrapstring
(XDR
*xdrs, char **sp)A primitive that calls
xdr_string
(xdrs,
sp, MAXUN.UNSIGNED); where
MAXUN.UNSIGNED
is the maximum value of an
unsigned integer. The xdr_wrapstring
() function
is handy because the RPC package passes a maximum of two XDR routines as
arguments, and xdr_string
(), one of the most
frequently used primitives, requires three. Returns one if it succeeds,
zero otherwise.
eXternal Data Representation Standard: Protocol Specification.
eXternal Data Representation: Sun Technical Notes.
XDR: External Data Representation Standard, Sun Microsystems, Inc., USC-ISI, RFC1014.
February 16, 1988 | macOS 14.6 |