Creates a duplicate of the string pointed to by src and returns a pointer to the new copy.
#include <unilib.h> unicode_t *unidup ( const unicode_t *s1);
(IN) Points to the string to be copied.
Returns the pointer to the new copy of the string if successful; otherwise, it returns NULL.
The memory for the new string is obtained by using the malloc function. The caller is responsible for freeing this memory by passing the returned pointer to the free function.