Can't read in a text file to load a struc

[FenixRising]

Hi,
I am doing an exercise that reads in a text file and loads the data into a struct. My problem is it doesn't read anything from the text file. I think it's the way I'm loading the data. Oh, it does read in the first record that tells the program how many contributor records to create, but nothing after that. Here it is:

//
#include <iostream>
#include <fstream>
#include <cstdlib>
const int strsize = 30;
const int SIZE = 60;

struct contributions {
    char fullname[strsize]; //name
    double donation;        //donation
};

int main()
{
    using namespace std;

    char filename[SIZE];
    ifstream inFile;        // object for handling file input

    cout << "Enter name of data file: ";
    cin.getline(filename, SIZE);
    inFile.open(filename);  // associate inFile with a file
    if (!inFile.is_open())  // failed to open file
    {
        cout << "Could not open the file " << filename << endl;
        cout << "Program terminating.\n";
        // cin.get();    // keep window open
        exit(EXIT_FAILURE);
    }

    int howmany = 0;

//   cout << "What's the number of contributions?: ";
    inFile >> howmany;
    int count = 0;
    contributions * ps = new contributions[howmany];

    while (count < howmany)
    {
      inFile.get(ps[count].fullname, strsize);
      inFile.get();
      inFile >> ps[count].donation;
      inFile.get();

      cout << "fullname: " << ps[count].fullname << "\n";
      cout << "donation: " << ps[count].donation << "\n";

      count++;
    }

    if (inFile.eof())
        cout << "End of file reached.\n";
    else if (inFile.fail())
        cout << "Input terminated by data mismatch.\n";
    else
        cout << "Input terminated for unknown reason.\n";
    if (count == 0)
        cout << "No data processed.\n";
    else
    {
        cout << "Items read: " << count << endl;
        //cout << "Sum: " << sum << endl;
        //cout << "Average: " << sum / count << endl;
    }
    inFile.close();

    cout << "Please enter one of the following choices:\n";
    cout << "a. Patrons\t" << "b. Grand Patrons\n";
    cout << "q. quit\n";
    cout << "Enter  choice ";
    int numdon;
    char choice;
    cin >> choice;
    while (choice != 'Q' && choice != 'q')
    {
        switch(choice)
        {
            case 'a':
            case 'A':
                    count = 0;
                    numdon = 0;
                    cout << "\tPatrons \n";
                    while (count < howmany)
                       {
                       if (ps[count].donation < 10000)
                         {
                         cout << ps[count].fullname << "\t" << ps[count].donation << "\n";
                         numdon++;
                         }
                         count++;
                       }
                       if (numdon == 0)
                         cout << "None\a\n";
                      break;
            case 'b':
            case 'B':
                    count = 0;
                    numdon = 0;
                    cout << "\tGrand Patrons \n";
                    while (count < howmany)
                       {
                       if (ps[count].donation >= 10000)
                         {
                         cout << ps[count].fullname << "\t" << ps[count].donation << "\n";
                         numdon++;
                         }
                         count++;
                       }
                       if (numdon == 0)
                         cout << "None\a\n";
                        break;

            default : cout << "Enter a valid choice.\n";
         }
         cout << "Next choice: ";
         cin >> choice;
     }

    cin.get();
    cin.get();
    return 0;
}

Here is the record input:

Data file:
4
Suz Stuz
55000
Froco Frock
5000
Yandi Yuck
100500
Dippy Dip
120000

9 records - each struct has two members; full name and donation.
First record should be number of contributors

Thanks in advance

[Philip Nicoletti]

You have ...

inFile >> howmany;

// ...

inFile.get(ps[count].fullname, strsize);

after reading in howmany, the '\n' is still in the input stream.
So the "get" reads an empty record. You need to get rid of the
'\n' from the first input.

inFile >> howmany;
inFile.ignore(1000,'\n');  // add this line

Is there a reason you are using "get" in the loop, instead of getline() ?

[Paul McKenzie]

Hi,
I am doing an exercise that reads in a text file and loads the data into a struct.

In addition,

1) Your program has a memory leak. You failed to delete[] the memory you allocated with new[].

2) You should check if the number you read in is >= 0. Otherwise your program will go haywire with a negative number.

Regards,

Paul McKenzie

[FenixRising]

Philip:

No reason for the get instead of getline. I meant to use getline. There are now two more issues (after I made your recommended changes). The donations figures are different in the struc after reading and loading them. And, I get an close error on the close file.

donations are (starting at the top):

5000
0
500
20000


Error message is: Input terminated for unknown reason (see program)

Thnx

Paul:

Thanks for the input. I'll make suggested changes.

[Philip Nicoletti]

You might need to post your current code for reading the file.

Did you change the first get() to getline() in the loop ? If so, you
should remove the first get() in your loop (since getline reads
and discards the '\n')

inFile.getline(ps[count].fullname,strsize);
//  inFile.get();

[2kaud]

Error message is: Input terminated for unknown reason (see program)

Correct! If you debug your program you'll easily find out why you always get this message. Hint. Look at the conditions you are using around inFile.eof() and inFile.fail().

Why not have fullname as a string in structure contributions rather than a char array? Using getline as suggested previously I read the contributions correctly. If you are getting the wrong values displayed then again you need to debug your program to establish the problem. Note that infile >> xxxx still leaves the trailing newline in the buffer as already mentioned together with the solution.

[FenixRising]

Hi,

I made the correction to the commenting out the inFile.get() line after the inFile.getline(<code>). And, that solved the problem of the invalid contributions being read in. Now, the only problem I still have is the invalid eof of the text file. I'm posting the new code. And, the error message is: Input terminated for unknown reason(See program). I looked at the code (which has worked in other programs) and don't see anything wrong.

#include <iostream>
#include <fstream>
#include <cstdlib>
const int strsize = 30;
const int SIZE = 60;

struct contributions {
    char fullname[strsize]; //name
    double donation;        //donation
};

int main()
{
    using namespace std;

    char filename[SIZE];
    ifstream inFile;        // object for handling file input

    cout << "Enter name of data file: ";
    cin.getline(filename, SIZE);
    inFile.open(filename);  // associate inFile with a file
    if (!inFile.is_open())  // failed to open file
    {
        cout << "Could not open the file " << filename << endl;
        cout << "Program terminating.\n";
        // cin.get();    // keep window open
        exit(EXIT_FAILURE);
    }

    int howmany = 0;

 //   cout << "What's the number of contributions?: ";
    inFile >> howmany;
    inFile.ignore(1000,'\n');

    int count = 0;
    contributions * ps = new contributions[howmany];

    while (count < howmany)
    {
      inFile.getline(ps[count].fullname, strsize);        //
      //inFile.get();
      inFile >> ps[count].donation;
      inFile.get();

      cout << "fullname: " << ps[count].fullname << "\n";
      cout << "donation: " << ps[count].donation << "\n";

      count++;
    }

    if (inFile.eof())
        cout << "End of file reached.\n";
    else if (inFile.fail())
        cout << "Input terminated by data mismatch.\n";
    else
        cout << "Input terminated for unknown reason.\n";
    if (count == 0)
        cout << "No data processed.\n";
    else
    {
        cout << "Items read: " << count << endl;
        //cout << "Sum: " << sum << endl;
        //cout << "Average: " << sum / count << endl;
    }
    inFile.close();

    cout << "Please enter one of the following choices:\n";
    cout << "a. Patrons\t" << "b. Grand Patrons\n";
    cout << "q. quit\n";
    cout << "Enter  choice ";
    int numdon;
    char choice;
    cin >> choice;
    while (choice != 'Q' && choice != 'q')
    {
        switch(choice)
        {
            case 'a':
            case 'A':
                    count = 0;
                    numdon = 0;
                    cout << "\tPatrons \n";
                    while (count < howmany)
                       {
                       if (ps[count].donation < 10000)
                         {
                         cout << ps[count].fullname << "\t" << ps[count].donation << "\n";
                         numdon++;
                         }
                         count++;
                       }
                       if (numdon == 0)
                         cout << "None\a\n";
                      break;
            case 'b':
            case 'B':
                    count = 0;
                    numdon = 0;
                    cout << "\tGrand Patrons \n";
                    while (count < howmany)
                       {
                       if (ps[count].donation >= 10000)
                         {
                         cout << ps[count].fullname << "\t" << ps[count].donation << "\n";
                         numdon++;
                         }
                         count++;
                       }
                       if (numdon == 0)
                         cout << "None\a\n";
                        break;

            default : cout << "Enter a valid choice.\n";
         }
         cout << "Next choice: ";
         cin >> choice;
     }
    delete ps;
    cin.get();
    cin.get();
    return 0;
}

Thnx

[GCDEF]

Again, learn to use the debugger and it will be obvious.

You have an unconditional else statement checking the file status.

[Paul McKenzie]

Hi,

I made the correction to the commenting out the inFile.get() line after the inFile.getline(<code>). And, that solved the problem of the invalid contributions being read in. Now, the only problem I still have is the invalid eof of the text file.

Continuing with my post:

 delete ps;

Should be:

 delete [] ps;

As to your issue now, what if there are more items than was stated on the first line of the file? In other words, you haven't reached the end-of-file, and the last read didn't fail.

Regards,

Paul McKenzie

[2kaud]

Input terminated for unknown reason(See program)

if (inFile.eof())
        cout << "End of file reached.\n";
    else if (inFile.fail())
        cout << "Input terminated by data mismatch.\n";
    else
        cout << "Input terminated for unknown reason.\n";

What happens if not eof and not fail?

I suspect you have extra chars at the end of your data file so when you have read your 4 data items you're not actually at end of file.

[FenixRising]

Hi,
I have resolved my last issue by removing two blank records in the input file. Thnx to everyone for the help.

[GCDEF]

Hi,
I have resolved my last issue by removing two blank records in the input file. Thnx to everyone for the help.

I wouldn't say you resolved it as much as you swept it under the rug.

[2kaud]

Hi,
I have resolved my last issue by removing two blank records in the input file. Thnx to everyone for the help.

No, you haven't fixed the problem. What you have done is alter the data to make it work with your incorrect code logic. Your program still has the same incorrect code!