How to use `malloc/calloc` inside a function?

Question

I want to create a function fill_table to fill a table dynamically. The tail n of the table is declared in the main() function,

int n = 0;
float* *T;
void show_table(int n) {}
void fill_table(int n) {}

int main() {
    printf(" Table dimension: ");
    scanf("%d", &n);
    fill_table(n);
    show_table(n);
  return 0;
}

I always get this error:

segmentation fault ./a.out

I try mes functions like that:

int n = 0;
float* *T=0;

void show_table(int n){
    printf("Show Table: \n");
    for (int i = 0; i < n; i++) {
      printf("%f ", *(T + i));
    }
}

void fill_table(int n) {
   *T=(float*)calloc(n, sizeof(float));;
  if (!T){
    printf("Memoire not allowe\n");
    exit(0);
  } else {
    for (int i = 0; i < n; i++) {
      printf("\nT[%d]= ", i+1);
      scanf("%f", (T + i));
    }
  }
}

Answer 1

After a lot of trial and error I found this solution:

• must declare table as

  float* T; //not float* *T;
  

• function fill_table:

  void fill_table(int n) {
     T=(float*)calloc(n, sizeof(float));;
    if (!T){
      printf("Memoire not allowe\n");
      exit(0);
    } else {
      for (int i = 0; i < n; i++) {
        printf("\nT[%d]= ", i+1);
        scanf("%f", (T + i));
      }
    }
  }
  

• function show_table:

  void show_table(int n){
      printf("Show Table: \n");
      for (int i = 0; i < n; i++) {
        printf("%f ", *(T + i));
      }
  }