Buffer overload Error(C++ Visual Studios)

Question

This is my code to read a file and store some lines from a position in the file and save it to an char array. The code works fine , if i call getVNP() once in the main. However when i try calling it the second time , I encounter a buffer overload error. I tried searching , but I haven found a solution please help thanks.

#include <iostream> // library that contain basic input/output functions
#include <fstream>  // library that contains file input/output functions
#include <string>
using namespace std;

void getVNP(std::string fileName, char* outStr)
{
    int end;
    int start;
    char sWord[] = "Virtual";  
    char eWord[] = "[Default";
    int position = 0; //this will be used incremental to fill characters in the array 
    int sWord_size = 0;
    int eWord_size = 0;
    //this loop is calculating the length of input word
    for (int i = 0; sWord[i] != '\0'; i++)
    {
        sWord_size++;
    }
    for (int i = 0; eWord[i] != '\0'; i++)
    {
        eWord_size++;
    }

    fstream fin(fileName.c_str());
    fin.seekg(0, fin.end);
    int epos = fin.tellg();
    fin.seekg(0, fin.beg);
    cout << epos;
    int array_size = epos; // define the size of character array
    char * array = new char[array_size]; // allocating size an array 

    //opening an input stream for file test.txt
    /*checking whether file could be opened or not. If file does not exist or don't have read permissions, file
    stream could not be opened.*/
    if (fin.is_open())
    {
        //file opened successfully so we are here
        cout << "File Opened successfully!!!. Reading data from file into array" << endl;
        //this loop run until end of file (eof) does not occur
        while(!fin.eof() && position < array_size)
        {
            fin.get(array[position]); //reading one character from file to array
            position++;
        }
        array[position - 1] = '\0'; //placing character array terminating character

        //this loop is searching for the word in the array
        for (int i = 0; array[i] != '\0'; i++)
        {
            for (int j = 0; sWord[j] != '\0' && j < 20 ; j++)
            {
                if (array[i] != sWord[j])
                {
                    break;
                }
                else
                {
                    i++;
                    if (sWord[j + 1] == '\0')
                    {
                        start = i-sWord_size+23;
                    }
                }
            }
        }
        for (int i = 0; array[i] != '\0'; i++)
        {
            for (int j = 0; eWord[j] != '\0' && j < 20 ; j++)
            {
                if (array[i] != eWord[j])
                {
                    break;
                }
                else
                {
                    i++;
                    if(eWord[j + 1] == '\0')
                    {
                        end = i-eWord_size - 11;
                    }
                }
            }
        }
        //take the start pos and the end pos text and put in string array s;
        fin.seekg(start);
        char *s = new char[end - start + 1];
        fin.read(s, end - start);
        s[end - start] = 0;
        size_t len = strlen(s);

        for(int i=0; i <len; ++i)
        {
            outStr[i] = s[i];
        }
        fin.close();
    }
    else //file could not be opened
    {
        cout << "File could not be opened." << endl;
    }
    getchar();
}

int main()
{
    std::string FilePath;
    std::string FilePath2;
    char aConfig[] = " ";
    char bConfig[] = " ";

    std::cout << "Please enter a file path: ";
    std::cin >> FilePath;
    std::cout << "Please enter a second file path: ";
    std::cin >> FilePath2;
    getVNP(FilePath, aConfig);
    cout << aConfig;
    getVNP(FilePath2, bConfig);
    cout << bConfig;

    getchar();
    return 0;
}

Answer 1

In main

char aConfig[] = " ";

creates array char[2] (space and null at the end). The second one ( bConfig ) creates another array char[2] .

In getVNP

outStr[i] = s[i];

You are writing to this static array while you have only place for 2 characters.

Condider changing aConfig and bConfig to std::string or allocating bigger buffer ( char aConfig[255]; ).

Answer 2

Your char aConfig[] is an array with 2 indices. The first one is the space and the second one \\0 to indicate the end of the array.

If your path is longer than 1 letter, you should either dynamically allocate this, pass the function a std::string by reference, or use the MAX_PATH define (thought I recommend the std::string solution).

void getVNP(std::string fileName, std::string &outStr);

Also you should clean up if you allocate something with new . This is not java.