Dereferencing pointer to incomplete type C

Question

Well, I'm getting this error and couldn't identify when i'm trying acess the fields.

In my bnum.c, i have the declaration of my struct:

    #include "bnum.h"

    struct num {
      char *vet;
      int tam;
    };

And in my bnum.h, I have:

    typedef struct num *b_num;

And in the main file I have:

    #include"bnum.h"
    int main(void){
    b_num b;
    b->tam = 5;

I'm using gcc on Linux Mint.

Answer 1

The main file does not have access to the structure definition, hence the error. You should move the definition

  struct num {
     char *vet;
     int tam;
  };

from .c to .h.

Answer 2

This is not a good-organized code. The struct declaration should be in the header file, this way any src file that will include the header will be familiar with that struct.