c++ - 不明白为什么我会收到错误消息

Question

我编写了这个程序，在来这里之前的最后两个小时里我一直在研究它。我收到错误消息 Function or variable unsafe consider using strcpy_s 我的书没有提到 strcpy_s。也许新的眼睛会看到我看不到的东西。这是我写的代码

  #include "stdafx.h"
  #include <iostream>
  #include <iomanip>
  #include <string>


  using namespace std;

  class HotelRoom
  {
   private:
char room_no [3];
char* guest;
int capacity;
int occupancy;
double rate;
 public:
HotelRoom(char room[],int, double = 89.00, char* n_p = 0, int= 0);
~HotelRoom();
void Display_get_number();
void Display_guest();
int get_capacity();
int get_status();
double get_rate();
void change_rate(double);
bool change_status(int);

};  
 HotelRoom::HotelRoom (char room[], int cap, double rt, char*n_p, int occup)
{
strcpy(room_no, room);
guest = new char[strlen(n_p) + 1];
strcpy(guest, n_p);
capacity = cap;
    occupancy = occup;
rate = rt;
cout << " defaut for the following " << room << endl << endl;
cout << " Capacity " << capacity << endl <<  endl;
cout << " rate " << rate << endl <<  endl;
cout << " Room Guest " << guest << endl << endl;
cout << " Occupancy " << occupancy <<  endl << endl;

  }
  HotelRoom::~HotelRoom()
  {
cout << "\nHotelRoom " << room_no <<" terminated. ";
delete [] guest;
  }
  void HotelRoom::Display_get_number()
  {
cout << room_no;
  }
  void HotelRoom::Display_guest()
  {
cout << guest;
  }
  int HotelRoom::get_capacity()
  {
return capacity;
  }
  int HotelRoom::get_status()
  {

return occupancy;
  }
   double HotelRoom::get_rate()
  {
return rate;
  }

   void HotelRoom::change_rate( double amount)
  {
rate += amount;
  }
  bool HotelRoom::change_status(int occupancy)
  {
    if (occupancy <= capacity )
    {
        this-> occupancy = occupancy;
        return true;
    }
    else
       return false;
   }



    int _tmain(int argc, _TCHAR* argv[])

 {

cout << setprecision(2)
     << setiosflags(ios::fixed)
     << setiosflags(ios::showpoint);

HotelRoom guest ("134",4,0, "Dennard Beale", 0);


cout << endl;
cout << " *****End of program***** " << endl;

system("pause");
return 0;

 }

Answer 1

strcpy_s是 strcpy 的一个版本，具有如 Security Enhancements in the CRT 中所述的安全增强功能.

strcpy 是“不安全的”，因为它会导致 Buffer Overflows .恶意用户可以 exploit this来控制你的程序。因此，Microsoft 引入了 strcpy_s(读作“字符串复制安全”)，使 strcpy 弃用。您应该在 Visual Studio 中使用 strcpy_s 而不是 strcpy。

或者，使用 std::string