ptr_to_ptr.c

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

struct test {
  char str[10];
  int  n;
};


void edit(struct test *);

int main(void)
{
  struct test example = {
    .str = "Hello",
    .n   = 5
  };
  struct test *example_ptr = malloc(sizeof(struct test));
  strcpy(example_ptr->str, "Hello2");
  example_ptr->n = 6;

  edit(&example);
  edit(example_ptr);

  printf("str: %s\n"
         "n:   %d\n",
         example.str,
         example.n);

  printf("str: %s\n"
         "n:   %d\n",
         example_ptr->str,
         example_ptr->n);
  return 0;
}

void edit(struct test *src)
{
  *src->str = 'R';
  src->n   = 10;
}