man/man3nsl/xdr_create.3nsl

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 xdr_create 3NSL "26 Sep 2000" "SunOS 5.11" "Networking Services Library Functions"
 NAME
xdr_create, xdr_destroy, xdrmem_create, xdrrec_create, xdrstdio_create -
library routines for external data representation stream creation
 SYNOPSIS

#include <rpc/xdr.h>

void xdr_destroy(XDR *xdrs);


void xdrmem_create(XDR *xdrs, const caddr_t addr, const uint_t size,
 const enum xdr_op op);


void xdrrec_create(XDR *xdrs, const uint_t sendsz, const uint_t recvsz,
 const caddr_t handle, const int (*readit)const void *read_handle,
 char *buf, const int len, const int (*writeit)
 const void *write_handle, const char *buf, const int len);


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


 DESCRIPTION

The 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 with the creation of XDR streams, which must be
created before any data can be translated into XDR format.
 "Routines"

See rpc(3NSL) for the definition of the XDR CLIENT and
SVCXPRT data structures. Any buffers passed to the XDR routines
must be properly aligned. Use malloc(3C) to allocate these buffers or be
sure that the buffer address is divisible evenly by four.

xdr_destroy()

A macro that invokes the destroy routine associated with the XDR stream,
xdrs. Private data structures associated with the stream are freed.
Using xdrs after xdr_destroy() is invoked is undefined.


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 less than size bytes long. The op
determines the direction of the XDR stream. The value of op can be
either XDR_ENCODE, XDR_DECODE, or XDR_FREE.


xdrrec_create()

This routine initializes the read-oriented XDR stream object pointed to
by xdrs. The stream's data is written to a buffer of size sendsz. A
value of 0 indicates the system should use a suitable default. The
stream's data is read from a buffer of size recvsz. It too can be set to
a suitable default by passing a 0 value. When a stream's output buffer
is full, writeit is called. Similarly, when a stream's input buffer is
empty, xdrrec_create() calls readit. The behavior of these two
routines is similar to the system calls read() and write(), except
that an appropriate handle, read_handle or write_handle, is passed
to the former routines as the first parameter instead of a file descriptor. See
read(2) and write(2), respectively. The XDR stream's op
field must be set by the caller.
This XDR stream implements an intermediate record stream. Therefore,
additional bytes in the stream are provided for record boundary information.


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. The value of op can be either XDR_ENCODE,
XDR_DECODE, or XDR_FREE.
The destroy routine associated with XDR streams calls fflush() on
the file stream, but never fclose(). See fclose(3C).


A failure of any of these functions can be detected by first initializing the
x_ops field in the XDR structure (xdrs-> x_ops) to
NULL before calling the xdr*_create() function. If the
x_ops field is still NULL, after the return from the
xdr*_create() function, the call has failed. If the x_ops field
contains some other value, assume that the call has succeeded.
 ATTRIBUTES

See attributes(5) for descriptions of the following attributes:


ATTRIBUTE TYPEATTRIBUTE VALUE
MT-LevelMT-Safe


 SEE ALSO

read(2), write(2), fclose(3C), malloc(3C),
rpc(3NSL), xdr_admin(3NSL), xdr_complex(3NSL),
xdr_simple(3NSL), attributes(5)