todDbB.cpp

#include <fstream>
using std::fstream;

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

#include <cctype>
using std::toupper;

struct tod
{
  int hour;
  int minute;
  int second;
  char descr[32];
};

void coutTod(const tod&);
void coutTod(int n, const tod t[]); // n = number of items in the array

int main()
{
  // initialize tod array to 0
  tod theTime[5] = {0};
  fstream fin;
  char userIn = 'X';

  // collect user input and check for input validity
  cout << "Do you want to read the times from the database? [Y/N]: ";
  while (userIn != 'Y' && userIn != 'N')
  {
    cin >> userIn;
    userIn = toupper(userIn); // convert user input to uppercase
    if (userIn != 'Y' && userIn != 'N') cout << "Invalid input, enter again: ";
  }

  // if user selected Y, open the database file, check for file validity,
  // read from the file, and then close the file.
  if(userIn == 'Y')
  {
    fin.open("todDb.dat", ios::in | ios::binary);
    if (!fin)
    {
      cout << "Error: Invalid file" << endl;
      return 0;
    }
    fin.read((char*)theTime, sizeof(tod)*5);
    fin.close(); // close the input file
  }

  // promt user to change info
  while(1)
  {
    cout << "This is the data for the 5 records" << endl;
    coutTod(5, theTime);
    userIn = 'X';

    // see if user wants to change data
    cout << "Do you want to change any of the data? [Y/N]: ";
    while(userIn != 'Y' && userIn != 'N')
    {
    cin >> userIn;
    userIn = toupper(userIn);
    if (userIn != 'Y' && userIn != 'N') // if input is invalid, prompt for input again
      cout << "Invalid input, enter again: ";
    }

    // if yes, change data
    if (userIn == 'Y')
    {
      int i;

      // get which one to change
      cout << "Which time of day would you like to change? [1-5]: ";
      while(1)
      {
        cin >> i;
        i--;
        if (i < 0 || i > 4) // if it's not within range, prompt for input again
          cout << "Invalid input, enter again: ";
        else break;
      }

      // get info to change theTime
      cout << "Enter the hour, minute, second, and description, all separated by spaces." << endl;
      cin >> theTime[i].hour >> theTime[i].minute >> theTime[i].second;
      cin.ignore(1, ' ');
      cin.getline(theTime[i].descr, 32);
    }

    // otherwise, break the loop
    else break;
  }



  fstream fout;
  fout.open("todDb.dat", ios::out|ios::binary); // open the database file for output,
  fout.write((char*)theTime, sizeof(tod)*5); // write the array to it,
  fout.close(); // then close the file.
}

// prints elements of a tod object
void coutTod(const tod& t)
{
  cout << t.descr << " is "
       << t.hour << (t.minute < 10 ? ":0" : ":")
       << t.minute << (t.second < 10 ? ":0" : ":")
       << t.second << endl;
}

// takes tod objects in an array and sends them to be printed
void coutTod(int n, const tod t[]) // n = number of items in the array
{
    for (int i=0;i < n;i++)
    {
      cout << (i + 1) << ". ";
    coutTod(t[i]);
    }
}