xdr_pointer()--Provide Pointer Chasing within Structures

 #include <rpc/xdr.h>

 bool_t xdr_pointer(XDR *xdrs,
                    char **objpp,
                    u_int objsize,
                    const xdrproc_t xdrobj);

The xdr_pointer() function provides pointer chasing within structures and serializes null pointers. This function can represent recursive data structures, such as binary trees or linked lists.

Pointer chasing is the substitution of the pointer itself with the actual structure it points to.

Parameters

xdrs  (Input) 

A pointer to the eXternal Data Representation (XDR) stream handle.

objpp  (I/O) 

A pointer to the character pointer of the data structure. If decoding and *objpp==NULL, then the memory is allocated by XDR.

objsize  (Input) 

The size of the structure.

xdrobj  (Input) 

The XDR filter for the object.

Authorities

No authorization is required.

Return Value

Error Conditions

None.

Error Messages

Example

See Code disclaimer information for information pertaining to code examples.

The following example shows how xdr_pointer() is used:

#include <xdr.h>

typedef struct node
{
        int              value;
        struct node *p;
} node ;

bool_t xdr_list(XDR *xdrs, node **p_node)
{
        return xdr_pointer(xdrs,(caddr *)p_node,
        sizeof(node),(xdrproc_t)xdr_node)
}

bool_t xdr_node(XDR *xdrs, node *p_node)
{
        xdr_int(xdrs,&(p_node->value));
        return xdr_list(xdrs,&(p_node->p));
}