c program Struct inside struct code example

Example 1: how to put a struct in another struct C

struct B {  // <-- declare before
  int number;
};
struct A {
 int data;
 B b; // <--- declare data member of `B`
 };

Example 2: function inside struct c

typedef struct client_t client_t, *pno;
struct client_t
{
        pid_t pid;
        char password[TAM_MAX]; // -> 50 chars
        pno next;

        pno (*AddClient)(client_t *);  <-- pointer to function    
};

pno client_t_AddClient(client_t *self) { /* code */ } <-- function

int main()
{

    client_t client;
    client.AddClient = client_t_AddClient; // probably really done in some init fn

    //code ..

    client.AddClient(&client);

}