Fig. // 14.13: fig14_13.cpp
// Writing to a random access file.
#include <iostream>
using std::cerr;
using std::endl;
using std::cout;
using std::cin;
using std::ios;
#include <iomanip>
using std::setw;
#include <fstream>
using std::ofstream;
#include <cstdlib>
#include "clientData.h" // ClientData class definition
int main()
{
int accountNumber;
char lastName[ 15 ];
char firstName[ 10 ];
double balance;
ofstream outCredit( "credit.dat", ios::binary );
// exit program if ofstream cannot open file
if ( !outCredit ) {
cerr << "File could not be opened." << endl;
exit( 1 );
} // end if
cout << "Enter account number "
<< "(1 to 100, 0 to end input)\n? ";
// require user to specify account number
ClientData client;
cin >> accountNumber;
client.setAccountNumber( accountNumber );
// user enters information, which is copied into file
while ( client.getAccountNumber() > 0 &&
client.getAccountNumber() <= 100 ) {
// user enters last name, first name and balance
cout << "Enter lastname, firstname, balance\n? ";
cin >> setw( 15 ) >> lastName;
cin >> setw( 10 ) >> firstName;
cin >> balance;
// set record lastName, firstName and balance values
client.setLastName( lastName );
client.setFirstName( firstName );
client.setBalance( balance );
// seek position in file of user-specified outCredit.seekp( record
( client.getAccountNumber() - 1 ) *
sizeof( ClientData ) );
// write user-specified information in file
outCredit.write(
reinterpret_cast< const char * >( &client ),
sizeof( ClientData ) );
// enable user to specify another account number
cout << "Enter account number\n? ";
cin >> accountNumber;
client.setAccountNumber( accountNumber );
} // end while
return 0;
} // end main
/**************************************************************************
* (C) Copyright 1992-2003 by Deitel & Associates, Inc. and Prentice *
* Hall. All Rights Reserved. *
* *
* DISCLAIMER: The authors and publisher of this book have used their *
* best efforts in preparing the book. These efforts include the *
* development, research, and testing of the theories and programs *
* to determine their effectiveness. The authors and publisher make *
* no warranty of any kind, expressed or implied, with regard to these *
* programs or to the documentation contained in these books. The authors *
* and publisher shall not be liable in any event for incidental or *
* consequential damages in connection with, or arising out of, the *
* furnishing, performance, or use of these programs. *
*************************************************************************/