xdr_complex(3N) xdr_complex(3N)
NAME
xdr_complex, xdr_array, xdr_bytes, xdr_opaque, xdr_pointer, xdr_reference, xdr_string, xdr_union, xdr_vector, xdr_wrapstring - library rou-
tines for external data representation
SYNOPSIS
#include <rpc/xdr.h>
DESCRIPTION
XDR library routines allow C programmers to describe complex 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 are the XDR library routines for complex data
structures. They require the creation of XDR stream (see xdr_create(3N)).
Routines
See rpc(3N) for the definition of the data structure. Note that any buffers passed to the XDR routines must be properly aligned. It is
suggested that be used to allocate these buffers or that the programmer insure that the buffer address is divisible evenly by four.
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 size of each of
the array's elements, and elproc is an XDR routine that translates between the array elements' C form and their external representa-
tion. If is null when decoding, allocates memory and points to it. This routine returns if it succeeds, otherwise.
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. If is null when decoding, allocates memory and points to it. This
routine returns if it succeeds, otherwise.
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 if it succeeds, otherwise.
Like except that it serializes pointers, whereas does not. Thus, can represent recursive data structures, such as binary trees or linked
lists. If is null when decoding, allocates memory and points to it.
provides pointer chasing within structures.
The parameter pp is the address of the pointer; size is the the structure that *pp points to; and proc is an XDR procedure that
translates the structure between its C form and its external representation. If is null when decoding, allocates memory and points
to it. This routine returns if it succeeds, otherwise.
Warning: this routine does not understand pointers. Use instead.
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.
If is null when decoding, allocates memory and points to it. This routine returns if it succeeds, otherwise. Note: can be used to
send an empty string (""), but not a NULL string.
translates between a discriminated C
and its corresponding external representation. It first translates the discriminant of the union located at dscmp. This discrimi-
nant is always an Next the union located at unp is translated. The parameter choices is a pointer to an array of 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 structure array is denoted by a routine of value If the discriminant is not found in
the choices array, then the defaultarm procedure is called (if it is not Returns if it succeeds, otherwise.
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 the element count of the array. The parameter elsize is the each of the array's elements, and elproc is an XDR routine that
translates between the array elements' C form and their external representation. This routine returns if it succeeds, otherwise.
A routine that calls
where maxuint is the maximum value of an unsigned integer.
Many routines, such as and take a function pointer of type which takes two arguments. one of the most frequently used routines,
requires three arguments, while only requires two. For these routines, is desirable. This routine returns if it succeeds, other-
wise.
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 support asynchronous cancellation or asynchronous signals.
SEE ALSO
rpc(3N), xdr_admin(3N), xdr_create(3N), xdr_simple(3N).
xdr_complex(3N)