How to copy a structure pointer?

Question

Is it possible to clone a structure pointer? Follow the code:

typedef struct{
    int numero;
}estrutura;

int main(int argc, char *argv[]){

    estrutura *i = (estrutura *)malloc(sizeof(estrutura));
    estrutura *d;

    i->numero = 5;

    printf("%d", i->numero);

}

I want the structure *d for example be the copy of the structure *i, so that if I change the value of i->numero, does not interfere with d->numero.

Answer 1

The first thing you need to do is allocate memory to the other structure. Then you should copy with memcpy().

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct {
    int numero;
} Estrutura;

int main(int argc, char *argv[]){
    Estrutura *i = malloc(sizeof(Estrutura));
    Estrutura *d = malloc(sizeof(Estrutura));
    i->numero = 5;
    memcpy(d, i, sizeof(Estrutura));
    i->numero = 6;
    printf("%d", d->numero);
    printf("%d", i->numero);
}

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

Note that you are copying the content of the object, because the pointer is always copied naturally.