Re: Structure having pointers

Hi,
when you write b=a you copy the memory of the struct instance a in b.
In this way you copy the pointer p of a in b. Now a.p and b.p point to
the same memory.
To make a depth copy of the struct you have to write a function:

struct Sample* SampleCopy(struct Sample* src)
{
struct Sample* b=NULL;
b=(struct Sample*)malloc(sizeof(struct Sample));
b.i=src.i;
b.p=(char*)malloc(sizeof(char)*(strlen(src.p)+1));
memcpy(b.p,src.p);
return b;
}

int main()
{
Sample a;
a.p = (char*)malloc(10);
Sample *b;
b = SampleCopy(&a);

free(a.p);
free(a);
printf("%s",b->p); //should work!!
}

I think in this way you may solve your problem... if I've understood.
Probably I've committed some errors in the code.. but I've not a
reference now!

Bye
Gio


On 29 Lug, 12:20, sam_...@xxxxxxxxxxx wrote:
Hi,

I have the following Struct,

Struct Sample
{
int i;
char *p;
};

int main()
{
Sample a;
a.p = malloc(10);
Sample b;
b = a;

}

Now i think a shallow copy is done and if i destry only on the object
there would be a dangling pointer.
How do i overcome this problem as C structures don't support
functions?

Thanks in advance!!!



.

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