CODEWITHSUNDEEP
c++visual-studio-2010visual-c++
Fjara
Fjara

Reputation: 93

Visual C++ - Cannot open text file

Simple program to open up a file and read it's contents. Then a test at the end to see if I did in fact get the information. Every time I run it it tells me that it cannot open the file. I will post the contents of SaleSlips below. Why isn't it opening the file? It is also attempting to delete the file every run as well. 

#include <iostream>
#include <fstream>
#include <cstdlib>
using namespace std;

struct SaleSlip{
    char name[20];
    int prodID;
    double value;
};

void main(){

    fstream slips;
    SaleSlip sales[17];
    slips.open("SaleSlips.txt", ios::in);
    if(slips.eof()){
        cout << "Cannot open file - SaleSlips.txt"<< endl;
        system("pause");
        exit(2);
    }
    int i = 0;
    while(!slips.eof()){
        slips.getline(sales[i].name, ' ');
        slips >> sales[i].prodID;
        slips.ignore(5, ' ');
        slips >> sales[i].value;
        slips.ignore(80, ' ');
        i++;
    }
    cout << sales[1].value;
    slips.close();
    system("pause");
}

Eric   1 200000.00
Sookie 2    200.00
Sookie 4    200.50

Upvotes: 0

Views: 3112

Answers (2)

Ken White
Ken White

Reputation: 125749

You have two problems:

You're opening the file for output (writing)

slips.open("SaleSlips.txt", ios::out);

Useios::in instead for input (reading)

slips.open("SaleSlips.txt", ios::in);

Next, you're immediately testing for !eof(), which is the wrong logic. 

if(!slips.eof())

You don't want to be at eof() when opening the file for input. eof() is end of file. When first opening the file for input you want to be at the beginning of the file; being at eof() is a bad thing. Your code should error out if eof() is true, not if it's false:

if(slips.eof()) {
  // It's an error if we're starting at eof()
}

Upvotes: 0

Egg
Egg

Reputation: 2066

You're opening the stream in output mode by using ios::out. Use ios::in to read from it.

You've got a lot of other issues, too. IE:

-The if(!slips.eof()) after the file open will always cause an exit unless the file is empty.
-In your while loop, you are (probably accidentally) attempting to write the prodID and value into the slips file using <<. Use >> to read from a stream and << to write to it.

Upvotes: 3

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