Wrong output with std::string using stoul, on integer array - c++

Question

Hi, I'm having trouble trying to convert a line of numbers, e.g.: 100 101 102, to (stoul) an dynamically allocated unsigned integer; the expected is that I can access number by number as an array, in an variable length input.
#include <iostream>
#include <new>
#include <string> //Memset
int console(){
std::string console_buffer;
unsigned long int* integersConverted = NULL;
unsigned int integersNumberOf = 0;
for( ; ; ){
std::getline(std::cin, console_buffer);
integersConverted = console_defaultSyntaxProcessing(console_buffer, &integersNumberOf);
std::cout << "Found the following integers from conversion: ";
for(unsigned int debug_tmp0 = 0; debug_tmp0 < integersNumberOf; debug_tmp0++){
std::cout << integersConverted[debug_tmp0] << " ";
std::cout << std::endl;
}
delete integersConverted;
integersConverted = NULL;
}
return 0;
}
unsigned long int* console_defaultSyntaxProcessing(std::string console_buffer, unsigned int* integersNumberOfUpdate){
*integersNumberOfUpdate = 0;
unsigned int integersNumberOf = 0;
unsigned long int* integersFound = NULL;
integersFound = new unsigned long int(sizeof(unsigned long int) * 1024);
std::size_t stringPosition = 0;
for( ; stringPosition < console_buffer.length() && integersNumberOf < 1024; ){
integersFound[integersNumberOf] = std::stoul(console_buffer, &stringPosition, 10); //10 = Decimal
integersNumberOf++;
}
*integersNumberOfUpdate = integersNumberOf;
return integersFound;
}
I'm getting correct value if I input only one number, but the whole 1024 array is printed if I input two numbers or more and all positions get the first integer. I've tried to manually set the function std::string to constant, zero the console_buffer.length() so it finds '\0', etc; unfortunately not worked..
UPDATE --- 5 minutes after the topic first posting;
The problem is, as Yashas answered, at console_defaultSyntaxProcessing for loop; stoul &stringPosition returns number of characters read from, not the position of std::string.
Another problem using stoul is, if I input 100 ( 101, it doesn't work, so follows the fixed code but shall not be used.
As lamandy suggested, use std::stringstream instead.
std::size_t stringPosition = 0;
std::size_t stringPositionSum = 0;
for( ; stringPosition < console_buffer.length() && integersNumberOf < 1024; ){
try{
integersFound[integersNumberOf] = std::stoul(&console_buffer[stringPositionSum], &stringPosition, 10);
integersNumberOf++;
stringPositionSum = stringPositionSum + stringPosition;
}
catch(std::exception& exception){
break;
} //This catch will be used constantly by this buggy code.

Answer 1

for( ; stringPosition < console_buffer.length() && integersNumberOf < 1024; ){
integersFound[integersNumberOf] = std::stoul(console_buffer, &stringPosition, 10); //10 = Decimal
integersNumberOf++;
}
does not do what you want.
You are passing the same string to std::stoul again and again. Your std::stoul function keeps reading the first number every time. When you had just one number, the stringPosition < console_buffer.length() caused your loop to stop. When you have more than one number, stringPosition will never exceed console_buffer.length().
The second parameter of std::stoul does not take where in the string to start reading from; it gives you the number of characters processed.
For the task you are dealing with, stringstream is what you need.
#include <iostream>
#include <sstream>
#include <array>
int main ()
{
std::istringstream console_buffer("123 345 3 5 2 3 4 5 6 7 7 232 34 332 234 55");
std::array<unsigned long, 1024> integerArray;
size_t count = 0;
while(console_buffer && count < integerArray.size())
console_buffer >> integerArray[count++];
for(int i = 0; i < count; i++)
std::cout<<integerArray[i] << ' ';
return 0;
}

Answer 2

Consider using std::vector and std::stringstream to ease your job.
std::vector<unsigned long int> StringToIntegerVector(const std::string& input)
{
std::istringstream iss(input);
unsigned long int temp;
std::vector<unsigned long int> results;
while (iss >> temp)
results.push_back(temp);
return results;
}