xdr - library routines for external data representation
#include <rpc/rpc.h>
bool_t xdr_array(XDR *xdrs, char **arrp, u_int *sizep,
u_int maxsize, u_ing elsize, xdrproc_t elproc)
bool_t xdr_bool(XDR *xdrs, bool_t *bp)
xdr_bytes(XDR *xdrs, char **sp, u_int *sizep, u_int maxsize)
bool_t xdr_char(XDR *xdrs, char *cp)
void xdr_destroy(XDR *xdrs)
bool_t xdr_double(XDR *xdrs, double *dp)
bool_t xdr_enum(XDR *xdrs, enum_t *ep)
bool_t xdr_float(XDR *xdrs, float *fp)
void xdr_free(xdrproc_t proc, char *objp)
void xdr_free(xdrproc_t proc, char *objp)
u_int xdr_getpos(XDR *xdrs)
long * xdr_inline(XDR *xdrs, int len)
bool_t xdr_int(XDR *xdrs, int *ip)
bool_t xdr_long(XDR *xdrs, long *lp)
void xdrmem_create(XDR *xdrs, char *addr, u_int size, enum xdr_op op)
bool_t xdr_opaque(XDR *xdrs, char *cp, u_int cnt)
bool_t 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) ())
bool_t xdrrec_endofrecord(XDR *xdrs, int sendnow)
bool_t xdrrec_eof(XDR *xdrs, int empty)
bool_t xdrrec_skiprecord(XDR *xdrs)
bool_t xdr_reference(XDR *xdrs, char **pp, u_int size, xdrproc_t proc)
xdr_setpos(XDR *xdrs, u_int pos)
bool_t xdr_short(XDR *xdrs, short *sp)
void xdrstdio_create(XDR *xdrs, FILE *file, enum xdr_op op)
bool_t xdr_string(XDR *xdrs, char **sp, u_int maxsize,
bool_t xdr_u_char(XDR *xdrs, unsigned char *ucp)
bool_t xdr_u_int(XDR *xdrs, unsigned *up)
bool_t xdr_u_long(XDR *xdrs, unsigned long *ulp)
bool_t xdr_u_short(XDR *xdrs, unsigned short *usp)
bool_t xdr_union(XDR *xdrs, int *dscmp, char *unp,
struct xdr_discrim *choices,
bool_t (*defaultarm) ())
bool_t xdr_vector(XDR *xdrs, char *arrp, u_int size,
u_int elsize, xdrproc_t elproc)
bool_t xdr_void(void)
bool_t xdr_wrapstring(XDR *xdrs, char **sp)
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.
Declarations for these routines are included when you include <rpc/rpc.h>.
xdr_array(XDR *xdrs, char **arrp, u_int *sizep,
u_int maxsize, u_ing elsize, xdrproc_t elproc)
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(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 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(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(3), xdr_opaque(3) or xdr_string(3).
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(3) is undefined.
xdr_double(XDR *xdrs, double *dp)
A filter primitive that translates between C 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 (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 and their external
representations. This routine returns one if it succeeds, zero
otherwise.
void
xdr_free(xdrproc_t proc, char *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).
u_int
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.
long *
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 Warning: xdr_inline(3) may
return NULL (0) if it cannot allocate a contiguous piece of a
buffer. Therefore the behavior may vary among XDR 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 integers and their
external representations. This routine returns one if it succeeds,
zero otherwise.
void
xdrmem_create(XDR *xdrs, char *addr, u_int size, enum xdr_op op)
This routine initializes the 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 or
xdr_opaque(XDR *xdrs, char *cp, u_int cnt)
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(XDR *xdrs, char **objpp, u_int objsize, xdrproc_t xdrobj)
Like xdr_reference(3) execpt that it serializes NULL
pointers, whereas xdr_reference(3) does not. Thus, xdr_pointer(3) can
represent recursive data structures, such as binary trees or linked
lists.
void
xdrrec_create(XDR *xdrs, u_int sendsize, u_int recvsize,
char *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 and 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(XDR *xdrs, int sendnow)
This routine can be invoked only on streams created by xdrrec_create(3).
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, int empty)
This routine can be invoked only on streams created by xdrrec_create(3).
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(3).
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
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(3) instead.
xdr_setpos(XDR *xdrs, u_int pos)
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(3). 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 integers and their
external representations. This routine returns one if it succeeds,
zero otherwise.
void
xdrstdio_create(XDR *xdrs, FILE *file, 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 stream file. The parameter op determines the
direction of the XDR stream (either or 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 C characters and their
external representations. This routine returns one if it succeeds,
zero otherwise.
xdr_u_int(XDR *xdrs, unsigned *up)
A filter primitive that translates between C 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 integers and their
external representations. This routine returns one if it succeeds,
zero otherwise.
xdr_u_short(XDR *xdrs, unsigned short *usp)
A filter primitive that translates between C integers and their
external representations. This routine returns one if it succeeds,
zero otherwise.
xdr_union(XDR *xdrs, int *dscmp, char *unp,
struct xdr_discrim *choices,
bool_t (*defaultarm) ())
/* defaultarm may equal NULL */
A filter primitive that translates between a discriminated C and
its corresponding external representation. It first translates the
discriminant of the union located at dscmp. This
discriminant is always an Next the union located at unp is
translated. The parameter choices is a pointer to an array
of xdr_discrim(3) 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(3) 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 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 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 parameter, where nothing is to be done.
xdr_wrapstring(XDR *xdrs, char **sp)
A primitive that calls where MAXUN.UNSIGNED is the maximum value of
an unsigned integer. xdr_wrapstring(3) is handy because the RPC
package passes a maximum of two XDR routines as parameters, and
xdr_string(3), one of the most frequently used
primitives, requires three. Returns one if it succeeds, zero
otherwise.
rpc(3)
The following manuals: eXternal Data Representation Standard: Protocol Specification, eXternal Data Representation: Sun Technical Notes,
XDR: External Data Representation Standard, RFC 1014, Sun Microsystems, Inc., USC-ISI.