// ZazouReadRegValue.cpp : définit le point d'entrée pour l'application console.
//

#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{
	HKEY rootKey = NULL;
	HKEY zKey;
	LPTSTR subKey;
	LPTSTR value;
	LPBYTE data;
	LPBYTE ptr;
	DWORD dataSize;
	DWORD keyType;
	DWORD i;
	DWORD err;

	if (argc < 4) {
		_tprintf(_T("USAGE: %s Clé_Racine Clé_Chemin Nom\n"), argv[0]);
		return 0;
	}

	if (!_tcscmp (argv[1], _T("HKCR"))) rootKey = HKEY_CLASSES_ROOT;
	if (!_tcscmp (argv[1], _T("HKLM"))) rootKey = HKEY_LOCAL_MACHINE;
	if (!_tcscmp (argv[1], _T("HKCU"))) rootKey = HKEY_CURRENT_USER;
	if (!_tcscmp (argv[1], _T("HKU")))  rootKey = HKEY_USERS;
	if (!rootKey) {
	if (argc < 4) {
		_tprintf(_T("USAGE: %s Clé_Racine Clé_Chemin Nom\n"), argv[0]);
		_tprintf(_T("       Clé = HKCR\n"));
		_tprintf(_T("ou     Clé = HKLM\n"));
		_tprintf(_T("ou     Clé = HKCU\n"));
		_tprintf(_T("ou     Clé = HKU\n"));
		return 0;
	}

	}
	subKey = argv[2];
	value = argv[3];

	if (ERROR_SUCCESS != (err = RegOpenKeyEx( rootKey, subKey, 0, KEY_QUERY_VALUE, &zKey ))) {
		_tprintf(_T("Can't open key: Err=%lu\n"), err);
		return (int)err;
	}

	if (ERROR_SUCCESS == (err = RegQueryValueEx ( zKey, LPCTSTR(value), 
												  0, NULL, NULL, &dataSize )))
	{
		data = (LPBYTE)malloc(dataSize);
		if (!data) {
			_tprintf(_T("Can't allocate memory\n"));
			return 1;
		}
		if (ERROR_SUCCESS ==  (err = RegQueryValueEx ( zKey, LPCTSTR(value), 
													   0, &keyType, data, &dataSize )))
		{
			switch (keyType) {
				case REG_SZ:
					_tprintf(_T("\"%s\"\n"), (LPTSTR)data);
					break;
				case REG_EXPAND_SZ:
					ptr = data;
					_tprintf(_T("\""));
					while ((TCHAR)(*ptr)!=_T('\0')) {
						_tprintf(_T("%c"), (TCHAR)(*ptr));
						ptr += sizeof(TCHAR); 
					}
					_tprintf(_T("\"\n"));
					break;
				case REG_MULTI_SZ:
					ptr = data;
					while ((TCHAR)(*ptr)!=_T('\0')) {
						_tprintf(_T("\"%s\"\n"), (LPTSTR)ptr);
						ptr += _tcslen((LPTSTR)ptr);
						/* Zéro terminal */
						ptr += sizeof(TCHAR); 
					}
					break;
				case REG_DWORD:
					_tprintf(_T("%lu\n"), *(DWORD*)data);
					break;
				default:
					_tprintf(_T("0x"));
					for (i=0; i<dataSize; ++i) {
						_tprintf(_T("%02x"), data[i]);
					}
					_tprintf(_T("\n"));
					break;
			}
		} else {
			_tprintf(_T("Can't get value: Err=%lu\n"), err);
			return (int)err;
		}
		free (data);
	} else {
		_tprintf(_T("Can't get value size: Err=%lu\n"), err);
		return (int)err;
	}

	RegCloseKey (zKey);
	return 0;
}