xdr_create(3N) xdr_create(3N)
NAME
xdr_create, xdr_destroy, xdrmem_create, xdrrec_create, xdrstdio_create - library routines for external data representation stream creation
SYNOPSIS
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 with the creation of XDR streams. XDR streams have to be created before any data can be translated into XDR format.
Routines
See rpc(3N) for the definition of the and data structures. Any buffers passed to the XDR routines must be properly aligned. It is sug-
gested either that malloc(3C) be used to allocate these buffers or that the programmer insure that the buffer address is divisible evenly
by four.
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 invoking is undefined.
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 parameter op determines the direction of the XDR stream. The value of op can be either or In the case where the value of size
exceeds resets size to
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 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 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 (see read(2) and write(2), respectively), 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. 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.
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 or
Warning: the destroy routine associated with such XDR streams calls on the file stream, but never (see fclose(3S)).
Failure of the function can be detected by first initializing the x_ops field in the structure to NULL before calling the function. After
the return from the function, if the x_ops field is still NULL, the call has failed. If the x_ops field contains some other value, assume
the call has succeeded. Failures cannot be detected for the and functions.
MULTITHREAD USAGE
Thread Safe: Yes
Cancel Safe: Yes
Fork Safe: No
Async-cancel Safe: No
Async-signal Safe: No
These functions can be called safely in a multithreaded environment. They may be cancellation points in that they call functions that are
cancel points.
In a multithreaded environment, these functions are not safe to be called by a child process after and before These functions should not be
called by a multithreaded application that supports asynchronous cancellation or asynchronous signals.
SEE ALSO
read(2), write(2), fclose(3S), malloc(3C), rpc(3N), xdr_admin(3N), xdr_complex(3N), xdr_simple(3N).
xdr_create(3N)