xdr_admin(3N)xdr_admin(3N)NAME
xdr_admin: xdr_getpos, xdr_inline, xdrrec_eof, xdr_setpos, xdr_sizeof -
library routines for external data representation
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 specifically with the management of the XDR stream.
Routines
See rpc(3N) for the definition of the XDR data structure.
#include <rpc/xdr.h>
u_int
xdr_getpos(const 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.
Therefore, applications written for portability should not depend on
this feature.
xdr_long_t *
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. The pointer is cast to 32 bits interger of type xdr_long_t
and is aligned on 32 bits boundary.
Note: 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, and
applications written for portability should not depend on this
feature.
bool_t
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 1 if the stream has no more input,
0 otherwise.
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xdr_admin(3N)xdr_admin(3N)
bool_t
xdr_setpos(XDR *xdrs, const 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. This routine returns 1 if the XDR stream was
repositioned, and 0 otherwise.
Note: it is difficult to reposition some types of XDR streams, so
this routine may fail with one type of stream and succeed with
another. Therefore, applications written for portability should not
depend on this feature.
unsigned long
xdr_sizeof(xdrproc_t func, void *data);
This routine returns the number of bytes required to encode data
using the XDR filter function func, excluding potential
overhead such as RPC headers or record markers. 0 is returned on
error. This information might be used to select between transport
protocols, or to determine the buffer size for various lower
levels of RPC client and server creation routines, or to
allocate storage when XDR is used outside of the RPC subsystem.
SEE ALSOrpc(3N), xdr_complex(3N), xdr_create(3N), xdr_simple(3N)
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