WindowsHelpers.cpp

///////////////////////////////////////////////////////////////////////
// WindowsHelper.cpp - small helper functions for using Windows API  //
// ver 1.0                                                           //
//-------------------------------------------------------------------//
// Jim Fawcett (c) copyright 2015                                    //
// All rights granted provided this copyright notice is retained     //
//-------------------------------------------------------------------//
// Language:    C++, Visual Studio 2015                              //
// Application: Several Projects, CSE687 - Object Oriented Design    //
// Author:      Jim Fawcett, Syracuse University, CST 4-187          //
//              jfawcett@twcny.rr.com                                //
///////////////////////////////////////////////////////////////////////

#define WIN32_LEAN_AND_MEAN

#include <Windows.h>
#include <string>
#include <winsock2.h>
#include "WindowsHelpers.h"

using namespace WindowsHelpers;

#pragma comment(lib, "Ws2_32.lib")

std::string WindowsHelpers::wstringToString(const std::wstring& wstr)
{
  std::string rtn;
  for (auto ch : wstr)
    rtn += static_cast<char>(ch);
  rtn += '\0';
  return rtn;
}

std::wstring WindowsHelpers::stringToWideString(const std::string& str)
{
  std::wstring rtn;
  for (auto ch : str)
    rtn += ch;
  rtn += static_cast<wchar_t>('\0');
  return rtn;
}

//----< get socket error message string >----------------------------

std::string WindowsHelpers::GetLastMsg(bool WantSocketMsg) {

  // ask system what type of error occurred

  DWORD errorCode;
  if (WantSocketMsg)
    errorCode = WSAGetLastError();
  else
    errorCode = GetLastError();
  if (errorCode == 0)
    return "no error";

  // map errorCode into a system defined error string

  DWORD dwFlags =
    FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER;
  LPCVOID lpSource = NULL;
  DWORD dwMessageID = errorCode;
  DWORD dwLanguageId = MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US);
  LPSTR lpBuffer;
  DWORD nSize = 0;
  va_list *Arguments = NULL;

  FormatMessage(
    dwFlags, lpSource, dwMessageID, dwLanguageId,
    (LPTSTR)&lpBuffer, nSize, Arguments
    );

  std::string _msg(lpBuffer);
  LocalFree(lpBuffer);
  return _msg;
}

#ifdef TEST_WINDOWSHELPERS

int main()
{

}

#endif