C++ WinAPI - reading and converting values from a file

Question

Am newbie in using WinAPI in C++. Just searched the internet for similar issues but unable to find correct one.

Am trying to read a file, which includes integer values and to save the values to a string Buffer. Then I need to convert the string to int array in order to calculate average values of all array elements.

At this moment I experience a problem, that values from a file are not being saved correctly - there is redundantion of some values at output.

As example, the input file looks like this: 1 2 5 3 96 72 33 47 43 91 The code is throwing values like: 1 2 5 3 96 72 33 47 43 91 43 91 43 91 43 91 43

Please see my code:

#include <iostream>
#include <Windows.h>
#include <string>
#include <tchar.h>
#include <cstdlib>
#include <ctime>
using namespace std;

int main( int argc, TCHAR *argv[] )
{
HANDLE hfile = CreateFile("RandomValues.txt",GENERIC_READ,0,NULL,OPEN_EXISTING,0,NULL); 
    DWORD dwBytesRead = 0;
    int SizeofFile=GetFileSize(hfile,NULL);
    LPSTR Buffer=NULL;
    DWORD dwSizeofBuffer = sizeof(Buffer);
    Buffer =( LPSTR ) GlobalAlloc( GPTR, MAX_PATH * sizeof(CHAR) );
    cout<<SizeofFile<<endl;
    for(unsigned int i=0;i<dwSizeofBuffer;i++)
    {
        ReadFile( hfile, Buffer, dwSizeofBuffer, &dwBytesRead, NULL );
        Buffer[i] = (wchar_t)Buffer[i];
        cout<<Buffer<<" ";  //checking, if values are read correct to Buffer
        
    }
    GlobalFree(Buffer);
    CloseHandle(hfile); 
    return 0;
}

UPDATE: I was asked to put the latest code - it's simpler (I think) and uses vector array and stoi function, although the input looks like: 11111. One user suggested to paste the new code here as edit:

#include <iostream>
#include <Windows.h>
#include <string>
#include <tchar.h>
#include <cstdlib>
#include <ctime>
#include <fstream>
#include <vector>
using namespace std;

int main( int argc, TCHAR *argv[] )
{
    //proces 2 uzyskuje dostep do plilu z liczbami i oblicza srednia liczb a wynik podaje na ekranie
    fstream File;
    File.open("RandomValues.txt", ios::in | ::ios::out);
    string Buffer = " ";
    if( File.good() ){
        for(int i=0;!File.eof();i++)
    {
        getline(File,Buffer);
        cout<<Buffer;
    }
    }
    
    
    //int str_length = Buffer.length(); 
    //int* Values;
    //Values = new int[str_length];
    vector <int> Values; 
    int j = 0;
    for (int i = 0; Buffer[i] != '\0'; i++) { 
  
         
         if (Buffer[i] == ' '){ 
            // Increment j to point to next 
            // array location 
            j++; 
        } 
        else { 
  
            // subtract str[i] by 48 to convert it to int 
            // Generate number by multiplying 10 and adding 
            // (int)(str[i]) 
           // Values[j] = Values[j] * 10 + (Buffer[i] - 48); //tries as well as *(Values + j) = *(Values + j) * 10 + (*(Buffer + i) -48) and with stoi(Buffer)
           Values.push_back(stoi(Buffer)); 
        } 
    } 
  
    for (unsigned int i = 0; i <= Values.size(); i++) { 
        cout << Values[i] << " "; 
         
    } 
//  delete [] Values;
    File.close();
    return 0;
}

Answer 1

Here's how you can read integers from a file into a vector. I am assuming that the integers are separated by white space only (i.e. there are no commas or similar characters in the file). If this is not true then the code has to be slightly more complicated (but not much).

// open the file
ifstream File("RandomValues.txt", ios::in);
if (!File.is_open())
    cerr << "failed to open file\n";

vector<int> Values;
// read the values (three lines of code !!!)
int val;
while (File >> val)
    Values.push_back(val);

// print out the values
for (unsigned int i = 0; i < Values.size(); i++) { 
    cout << Values[i] << " ";
cout << '\n';

Answer 2

I was suggested to use standard fstream method, of course I have it and it reads the file content correctly, the problem started while converting the values from string to int array. I put here full code to see it better than on pastebin:

#include <iostream>
#include <Windows.h>
#include <string>
#include <tchar.h>
#include <cstdlib>
#include <ctime>
#include <fstream>
using namespace std;

int main( int argc, TCHAR *argv[] )
{
    //proces 2 uzyskuje dostep do plilu z liczbami i oblicza srednia liczb a wynik podaje na ekranie
    fstream File;
    File.open("RandomValues.txt", ios::in | ::ios::out);
    string Buffer = " ";
    for(int i=0;!File.eof();i++)
    {
        getline(File,Buffer);
        cout<<Buffer;
    }
    
    int str_length = Buffer.length(); 
    int* Values = new int(str_length);
    int j = 0;
    for (int i = 0; Buffer[i] != '\0'; i++) { 
  
         
         if (Buffer[i] == ' '){ 
            // Increment j to point to next 
            // array location 
            j++; 
        } 
        else { 
  
            // subtract str[i] by 48 to convert it to int 
            // Generate number by multiplying 10 and adding 
            // (int)(str[i]) 
            Values[j] = Values[j] * 10 + (Buffer[i] - 48); //tries as well as *(Values + j) = *(Values + j) * 10 + (*(Buffer + i) -48) and with stoi(Buffer)
        } 
    } 
  
    for (unsigned int i = 0; i <= sizeof(Values); i++) { 
        cout << Values[i] << " "; 
         
    } 
    delete [] Values;
    File.close();
    return 0;
}