指针在从函数 [duplicate] 返回后为 NULL

问：

我是 C 编程的初学者。当函数返回 main（） 时，两个 int 指针返回 NULL，但在函数中它们指向正确的值。你有什么建议吗？

int main(){
    int k_attivi=0, n=0, in_game = 0, i, k=0;
    int *array_indici = NULL, *array_ingame = NULL;
    Player *players = NULL;    

    players = upload_players(&k, &in_game, &n, &k_attivi, array_indici, array_ingame);
            
    return 0;
}

Player *upload_players(int *k, int *in_game, int *n_tot, int *k_attivi, int* array_indici,  int* array_in_game){
    FILE *partita = NULL;
    Player *players=NULL;

    partita = fopen("file.bin", "rb");

    if(partita==NULL)
        exit (-1);

    fread(k, sizeof(int ), 1, partita);
    players = calloc(*k, sizeof(Player));
    fread(players, sizeof (Player), *k, partita);
    fread(in_game, sizeof(int ), 1, partita);
    if(*in_game == 1){
       fread(n_tot, sizeof(int), 1, partita);
       fread(k_attivi, sizeof(int), 1, partita);
       array_indici = calloc(*k_attivi, sizeof(int));
       fread(array_indici, sizeof(int), *k_attivi, partita);
       array_in_game = calloc(*k, sizeof(int));
       fread(array_in_game, sizeof(int), *k, partita);
    }
    fclose(partita);
    return players;
}