basic_ostream::write

Inserts a block of binary data into an output stream.

  basic_ostream<charT, traits>& write

  (const char_type* s, streamsize n);  

The overloaded function write() is used to insert a block of binary data into a stream. This function can be used to write an object by casting that object as a unsigned char pointer. If the operation fails, setstate(badbit) is called.

A reference to ostream. The this pointer is returned.

basic_istream::read

#include <iostream>
#include <fstream>
#include <iomanip>
#include <cstdlib>
#include <cstring>

struct stock { 
   char name[80];
   double price;
   long trades;
};

char *Exchange = "BBSE";
char *Company = "Big Bucks Inc.";

int main()
{
using namespace std;
   stock Opening, Closing;
   strcpy(Opening.name, Company);
   Opening.price = 180.25;
   Opening.trades = 581300;

      // open file for output
   ofstream Market(Exchange, 
         ios::out | ios::trunc | ios::binary); 

   if(!Market.is_open()) 
   {cout << "can't open file for output"; exit(1);}

   Market.write((char*) &Opening, sizeof(stock));
    Market.close();

     // open file for input

   ifstream Market2(Exchange, ios::in | ios::binary);

   if(!Market2.is_open()) 
   {cout << "can't open file for input"; exit(2);}

   Market2.read((char*) &Closing, sizeof(stock));
   cout << Closing.name << "\n"
      << "The number of trades was: " 
      << Closing.trades << '\n';

   cout << fixed << setprecision(2)
      << "The closing price is: $" 
      << Closing.price << endl;

   Market2.close();
   return 0;
}

Result:

  Big Bucks Inc.

  The number of trades was: 581300

  The closing price is: $180.25