///////////////////////////////////////////////////////////////
//  addvalue.cpp  -  demonstrate adding value to registry    //
//  ver 1.0                                                  //
//                                                           //
//  Jim Fawcett, CST 2-187, Syracuse Univ                    //
//  fawcett@ecs.syr.edu, (315) 443-3948                      //
//                                                           //
//  Modified from Win32 System Services, Marshall Brain,     //
//  Prentice Hall, 1996                                      //
///////////////////////////////////////////////////////////////
//  Note:                                                    //
//    View result with regedit.exe (don't modify anything!)  //
//                                                           //
///////////////////////////////////////////////////////////////

#include <windows.h>
#include <conio.h>
#include <iostream>
#include <string>
using namespace std;

void main(int argc, char *argv[]) {

  LONG ret;
  HKEY keyHandle1, keyHandle2;
  DWORD disposition;

  cout << "\n  Demonstrating Adding Value to Registry "
       << "\n ========================================\n";

// get key and value from command line

  if(argc == 1) {
    cout << "\n  please enter key and value\n\n";
    return;
  }
  char *key   = argv[argc-2];
  char *value = argv[argc-1];
  cout << "\n  do you want to add the value:\n    \"" << value
       << "\"\n  to the subkey \"Sample Key\" of the key:\n    " 
       << key << " ? ";
  char ch = _getche();
  cout << "\n";
  if(tolower(ch) == 'n') {
    return;
  }

// add or open key

  ret=RegCreateKeyEx(
        HKEY_CURRENT_USER,
        key,
        0, 
        NULL, 
        REG_OPTION_VOLATILE,
        KEY_ALL_ACCESS, 
        NULL, 
        &keyHandle1,
        &disposition
      );

//

  if (ret != ERROR_SUCCESS) {
    cerr << "\n  Unable to create key or open key" << endl;
    return;
  }
  else
    cout << "\n  opened key: " << key << "\n";

// add or open subkey

  char *subkey = "Sample Key";

  ret=RegCreateKeyEx(
        keyHandle1,
        subkey,
        0,
        NULL,
        REG_OPTION_VOLATILE,
        KEY_ALL_ACCESS, 
        NULL, 
        &keyHandle2,
        &disposition
      );
  
  if (ret != ERROR_SUCCESS) {
    cerr << "Unable to create or open subkey" << endl;
    return;
  }
  else
    cout << "\n  opened subkey: " << subkey << "\n";

// Add new value to subkey

  ret=RegSetValueEx(
        keyHandle2,           // handle of key with value
        "sampleValue",        // name of value to set
        0,                    // reserved
        REG_SZ,               // value type
        (CONST BYTE *) value, // location of value data
        strlen(value)+1       // size of value data
      );
    
  if (ret != ERROR_SUCCESS) {
    cerr << "Unable to modify subkey: " << subkey << "\n\n";
    return;
  }
  else
    cout << "\n  modified subkey: " << subkey << "\n\n";

// close the keys

  ret=RegCloseKey(keyHandle1);
  ret=RegCloseKey(keyHandle2);
}