Thread: Problem with atoi()?

I've done a little program which reads in info from a text file, but there seems to be a problem when I try to output certain numbers.

Code for the program in question:

Code:

#include <iostream>
#include <conio>
#include <vector>
#include <fstream>
using namespace std;
namespace Myprog {
  namespace Globals{};

  class Example {
    unsigned int counter;
  public:
    Example(unsigned int val)
    {
      counter = val;
    }
    
    unsigned int get_val() { return counter; }

  };
  
  namespace Globals {
    vector <Example *> objects;
    ifstream in;
  }
  
  namespace Script_Processing {
    bool make_example();
  
    void read_script()
    {
      Globals::in.open("script.txt", ios::in | ios::binary); // The binary flag doesn't seem to make a difference.
      if(!Globals::in) {
        cout << "Unable to open script file.\n";
        exit(1);
      }
      string hold_read; // Holds the string currently being tested.
      for( ; ; ) {
        while(isspace(Globals::in.peek())) Globals::in.get();
        Globals::in >> hold_read.begin();
        if(!strcmp(hold_read.begin(), "MakeExample")) {
          cout << "About to call make_example()\n";
          if(Script_Processing::make_example()) return;
        }
        if(Globals::in.eof()) {
          cout << "Error processing script.\n";
          exit(1);
        }
      }
    }

    bool make_example()
    {
      cout << "Inside make_example()\n";
      string hold_read1;
      string hold_read2;
      for( ; ; ) {
        while(isspace(Globals::in.peek())) Globals::in.get();
        if(Globals::in.peek() == '{') {
          Globals::in.get();
          continue;
        }
        else break;
      }
      Globals::in >> hold_read1.begin();
      if(!strcmp(hold_read1.begin(), "IntVar")) {
        while(isspace(Globals::in.peek())) Globals::in.get();
        Globals::in >> hold_read2.begin();
        Globals::objects.push_back(new Example(atoi(hold_read2.begin())));
        return true;
      }
      return false;
    }
  } // End of namespace Script_Processing;




  int main()
  {
    Script_Processing::read_script();

    cout << "Val in object: " << Globals::objects[0]->get_val() << '\n';

    cout << "Not stuck in an infinite loop!\n";
    
    delete Globals::objects[0];

    getch();

    return 0;
  }
} // End of namespace myprog;

The script it reads from (a text file called script):

MakeExample {
IntVar 196010
}

The problem is that when the first number is either 1 or 0, the value output has a number of commas which seem to be related to the number of leading 1s or 0s (except when the number is 10, 100 etc in which case there are a lot of commas). I'm wondering if the problem is somewhere other than the atoi() call though, because this other little test program seems to work OK:

#include <iostream>
#include <conio>
using namespace std;

Code:

int main()
{
  char *text = "196010";
  int val = atoi(text);
  cout << val << '\n';
  
  getch();
  
  return 0;
}

Any suggestions?

Just followed your advice and the problem seems to be fixed.

What's all the .begin() stuff?

I couldn't find anything about an operator>> for use with strings in my documentation on istream so I assumed that I would have to do everything through char pointers. Changing to using the string itself seems to solve the problem. Intend to look up exactly what operator==(string, char*) and stream.c_str do when I do more rigorous testing.

Still have to test the advice regarding EOF though, I assumed I would slip up on that somehow.

Thanks.

Make sure you actually #include<string>.