performing a "deep copy" on a nested structure

Hi,

I have the ff data types :

typedef enum {
    VAL_LONG    ,
    VAL_DOUBLE    ,
    VAL_STRING    ,
    VAL_DATASET
}ValueTypeEnum ;

typedef union {
    long    lval ;
    double    fval ;
    char*    sval ;
    void*    ptr ;
} Value ;

typedef struct {
    int       magic ;
    int       version ;
}Header ;

typedef struct  {
    char      label[20] ;
    id        int ;
}Key ;

typedef struct {
    Header     *hdr ;
    char       *subject ;
    Key        key ;
    ValueTypeEnum     type ;
    Value      value ;
    size_t     size ;
}MotherStruct ;


Pseudo code:
=============

MotherStruct *pMS_source = (MotherStruct*)calloc(1, sizeof(MotherStruct));

pMS_source->hdr = CreateHeader();
pMS_source->subject = strdup("Test Subject") ;
pMS_source->key = CreateKey("Test", 2000) ;
pMS_source->type = VAL_STRING ;
pMS_source->value.sval = strdup("Homer Simpson") ;
pMS_source->size = /* How do I calculate this ? */


void MakeMSClone(MotherStruct *pMS_Dest, const MotherStruct *pMS_source) {
 	memmove(pMS_dest,pMS_source, pMS_Source->size) ;
	
}



MTIA

.