Read Binary value

Hi there,

Code:

---

#include <iostream>
#include <fstream>
using std::cin;
using std::cout;
using std::ofstream;
using std::ifstream;
using std::fstream;
using std::ios;
using std::endl;

struct Books
{
char *BookName;
int Pages;
};

void write_binary(Books A);
void read_binary();

int main()
{
        Books A;
        A.BookName="C++";
        A.Pages=450;
        write_binary(A);
        return 0;
}

void write_binary(Books A)
{
    fstream binary_file("c:\\test.dat",ios::out|ios::binary|ios::app);
    binary_file.write(reinterpret_cast<char *>(&A),sizeof(Books));
    binary_file.close();
}

void read_binary()
{
    Books B;
    fstream binary_file("c:\\test.dat",ios::binary|ios::in);
    binary_file.read(reinterpret_cast<char *>(&B),sizeof(Books));
    binary_file.close();

    cout<<"Book's name : "<<B.BookName<<endl;
    cout<<"Pages :"<< B.Pages<<endl;

}

---

Code:

---

int main()
{
        read_binary();
        return 0;
}

---

the result i have seen is
Book's name : C:\test.dat
Pages : 1

Why the result is not the same as i have assigned? :confused:

Thanks for advance

the problem is that you're merely writing / reading the value of the char pointer, not the string

delete test.dat, then try these changes for the input

Code:

---

struct Books
{
char BookName[30];
int Pages;
};

void write_binary(Books A);
void read_binary();

int main()
{
        Books A;
        strcpy(A.BookName, "C++");
        A.Pages=450;
        write_binary(A);
        return 0;
}

---

The result of this time is in the attach file
please see and help me how should i solve it.

do you have any example for writing/reading binary file?

thanks

it works for me. are you sure you deleted test.dat before you ran the new writing program?

If i delete test.dat, how can i specify a file name where to write them?

Hey dis1411, It just works for me. :)
maybe i was mistake something.

can you help me a little more....
If i have inserted for 3 records, how can i move to next one?

Thanks a lot dis1411 :)