C++ Using pointers on structure and saving them on files -

soo have issue, im using pointers on structures , saving values on file

        struct compracli{         char nomeartigo[50];         char codigo[50];         char nomecli[50];         char data[50];     };  int compra(int l){ compracli *ptr, d; file *arquivo; ptr = &d;  if((arquivo = fopen("compras.dat", "rb+")) !=null){             //colocar apontadores dentro dos arquivos             system("cls");             cout<<"adicinar um pedido de compra!"<<endl;             cin.sync();             cout<<"adicione o nome artigo: ";             cin >> (*ptr).nomeartigo;             fwrite(ptr->nomeartigo, sizeof(ptr->nomeartigo), 1, arquivo);             cin.sync();             cout<<"adicione o codigo artigo: ";             cin >> (*ptr).codigo;             fwrite(ptr->codigo, sizeof(ptr->codigo), 2, arquivo);             cin.sync();             cout<<"adicione o nome cliente: ";             cin >> (*ptr).nomecli;             fwrite(ptr->nomecli, sizeof(ptr->nomecli), 3, arquivo);             cin.sync();             cout<<"adicione data de encomenda: ";             cin >> (*ptr).data;             fwrite(ptr->data, sizeof(ptr->data), 4, arquivo);             cin.sync();              }else{                 cout<<"erro na base de dados, de momento nao poderá aceder, tente mais tarde"<<endl;              }              fclose(arquivo);      return 0; 

the problem is, saving first value, means (*ptr).nomeartigo . @ first thought because of buffer, maybe full, soo tried clean using cin.sync(); still didnt worked out. thought might problem using "lines" example "fwrite(ptr->data, sizeof(ptr->data), 4, arquivo);" "4", thought saving in same line why causing problems. still didnt worked out! im out of ideas, knows how to?

cin >> (*ptr).nomeartigo; fwrite(ptr->nomeartigo, sizeof(ptr->nomeartigo), 1, arquivo); 

nomeartigo char array. writes bytes in array, including trailing \0 byte operator>> puts there, , uninitialized data follows. may or may not wrong. depends on how read back, did not show code.

fwrite(ptr->codigo, sizeof(ptr->codigo), 2, arquivo); 

this, , remaining fwrite()s wrong.

this writes sizeof(ptr->codigo)*2 bytes. not want. there sizeof(ptr->codigo) bytes write here.

all fwrite()s, except first ones write much. third parameter fwrite() not line number, of kind.

additionally, since c++, should not using file *, rather std::fstream. also, operator>> on char array not bound-limited, , vulnerable buffer overruns.