Parsing command line arguments in a unicode C++ application

Question

How can I parse integers passed to an application as command line arguments if the app is unicode?

Unicode apps have a main like this:

int _tmain(int argc, _TCHAR* argv[])

argv[?] is a wchar_t*. That means i can't use atoi. How can I convert it to an integer? Is stringstream the best option?

Answer 1

Dry coded and I don't develop on Windows, but using TCLAP, this should get you running with wide character argv values:

#include <iostream>

#ifdef WINDOWS
# define TCLAP_NAMESTARTSTRING "~~"
# define TCLAP_FLAGSTARTSTRING "/"
#endif
#include "tclap/CmdLine.h"

int main(int argc, _TCHAR *argv[]) {
  int myInt = -1;
  try {
    TCLAP::ValueArg<int> intArg;
    TCLAP::CmdLine cmd("this is a message", ' ', "0.99" );
    cmd.add(intArg);
    cmd.parse(argc, argv);
    if (intArg.isSet())
      myInt = intArg.getValue();
  } catch (TCLAP::ArgException& e) {
    std::cout << "ERROR: " << e.error() << " " << e.argId() << endl;
  }
  std::cout << "My Int: " << myInt << std::endl;
  return 0;
}

Answer 2

I personally would use stringstreams, here's some code to get you started:

#include <sstream>
#include <iostream>

using namespace std;

typedef basic_istringstream<_TCHAR> ITSS;

int _tmain(int argc, _TCHAR *argv[]) {

    ITSS s(argv[0]);
    int i = 0;
    s >> i;
    if (s) {
        cout << "i + 1 = " << i + 1 << endl;
    }
    else {
        cerr << "Bad argument - expected integer" << endl;
    }
}