C / C++ / MFC

Sumesh Somanathan wrote:

I have a unicode text file and tried to read it backward

void CMainFrame::OnStartTimer()
{
   m_nTimer = SetTimer(1, 2000, 0);
}

void CMainFrame::OnStopTimer()
{
   KillTimer(m_nTimer);
}

void CMainFrame::OnTimer(UINT nIDEvent)
{
   MessageBeep(0xFFFFFFFF);   // Beep
   MessageBox(HWND_DESKTOP,"Text here","Text here",MB_OK);
   // Call base class handler.
   CMDIFrameWnd::OnTimer(nIDEvent);
}

ndx = 0;
                doubleZero = false;
                szRgVal = sizeof(rgValue);

                for(int i=0; i < szRgVal; i++) {
                    if (!rgValue[i] == '\0\0') {
                        szInstance[ndx++] = rgValue[i];
                        doubleZero = false;
                    }
                    else {
                        if (doubleZero == false) {
                            szInstance[ndx++] = ';';
                            doubleZero = true;
                        }
                        else {
                            szInstance[ndx++] = '\0';
                            break;
                        }
                    }
                    i++;
                }

                maxStr = strlen(szInstance);
                szInstance[maxStr-0] = (char)'\0';
                printf(" SQL Server Instance: %s %i\n", szInstance, strlen(szInstance) );

ndx = 0;
szRgVal = sizeof(rgValue);
 
for(int i=0; i < szRgVal; i++) {
  if (rgValue[i] == '\0' && rgValue[i+1] == '\0' && rgValue[i+2] == '\0' && rgValue[i+3] == '\0') {
    szInstance[ndx++] = '\0'; //very end
    break;
  }
  else {
    if (rgValue[i] == '\0' && rgValue[i+1] == '\0' && rgValue[i+2] == '\0') {
      szInstance[ndx++] = ';'; //word end
      i++;
    }
  else
    szInstance[ndx++] = rgValue[i];
  i++;
}

else {
   if (rgValue[i] == '\0' && rgValue[i+1] == '\0' && rgValue[i+2] == '\0') {
     szInstance[ndx++] = ';'; //word end
     i++;
   }

char* CA_Registry::_get_SQLServer_InstalledInstances( void )
{
	HKEY keyHandle;
	char rgValue[1024];
	char szInstance[1024];
	CString regPath = L"SOFTWARE\\Microsoft\\Microsoft SQL Server\\";
	CString regReq = L"InstalledInstances";
	DWORD size1 = sizeof(rgValue);
	DWORD Type;
	DWORD dwType = 0;
	DWORD regStatus = REG_MULTI_SZ;

	int ndx=0;
	int szRgVal=0;
	int maxStr=0;
	bool doubleZero;
			
	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regPath, 0, KEY_QUERY_VALUE, &keyHandle) == ERROR_SUCCESS) {
		dwType = REG_MULTI_SZ;
		regStatus = RegQueryValueEx( keyHandle, regReq, NULL, &Type, (LPBYTE)rgValue, &size1);
			
		switch ( regStatus ) {
			case ERROR_SUCCESS:
				ndx = 0;
				doubleZero = false;
				szRgVal = sizeof(rgValue);
	
				for(int i=0; i < szRgVal; i++) {
                    if (!rgValue[i] == '\0\0') {
                        szInstance[ndx++] = rgValue[i];
                        doubleZero = false;
                    }
                    else {
                        if (doubleZero == false) {
                            szInstance[ndx++] = ';';
                            doubleZero = true;
                        }
                        else {
                            szInstance[ndx++] = '\0';
                            break;
                        }
                    }
                    i++;
				}
	
				maxStr = strlen(szInstance);	
				szInstance[maxStr-0] = (char)'\0';
				printf(" SQL Server Instance: %s %i\n", szInstance, strlen(szInstance) );				
								
				RegCloseKey(keyHandle);
				cout << "key was read successfully\n";
				break;

			case ERROR_MORE_DATA:
				cout << "Buffer too small\n";
				break;			

			default:			
				cout << "Count not read key\n";
		}
	}
	else {
		cout << "Can not open key";
		cin.ignore();
	}
	
	int strSize = sizeof(szInstance);	
	char *szReturnValue = new char[strSize];	
	for(int i = 0; i < strSize; i++) {
		szReturnValue[i]=szInstance[i];		
	}	
	maxStr=strlen(szReturnValue);	
	szReturnValue[maxStr-0]=(char)'\0';

	return szReturnValue;

	delete [] szReturnValue;
}

wchar_t* CA_Registry::_get_SQLServer_Version( const wchar_t *szSQLInstance )
{
	HKEY keyHandle;
	
	char rgValue [1024];
	char szVersion[1024];

	// Declare the Prefix and Suffix of the Reg Key
	char szRegPath[125];
	char *szRegPath_Prefix = "SOFTWARE\\Microsoft\\Microsoft SQL Server\\";
	char *szRegPath_Suffix = "\\MSSQLServer\\CurrentVersion\\";

	// Calculate the String Lengths
	int iRegPath_Prefix = strlen(szRegPath_Prefix);
	//int iRegPath_Instance = strlen(szSQLInstance);
	int iRegPath_Suffix = strlen(szRegPath_Suffix);
	
	//Build the Char Arrays
	strncpy_s(szRegPath, _countof(szRegPath), szRegPath_Prefix, iRegPath_Prefix);
	//strncat_s(szRegPath, _countof(szRegPath), szSQLInstance, iRegPath_Instance);
	strncat_s(szRegPath, _countof(szRegPath), szRegPath_Suffix, iRegPath_Suffix);
	
	// Convert the Char Arrays to Wide String
	int buffSize = (int)strlen(szRegPath) + 1;
	LPWSTR lpRegPath = new wchar_t[buffSize];
	MultiByteToWideChar(CP_ACP, 0, szRegPath, buffSize, lpRegPath, buffSize);
	
	LPWSTR lpRegReq = L"CurrentVersion";
		
	DWORD size1 = sizeof(rgValue);
	DWORD Type;
	DWORD dwType = 0;
	DWORD regStatus = REG_SZ;

	int ndx=0;
	int szRgVal;
	int maxStr;	
			
	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, lpRegPath, 0, KEY_QUERY_VALUE, &keyHandle) == ERROR_SUCCESS) {
		
		dwType = REG_SZ;
		regStatus = RegQueryValueEx( keyHandle, lpRegReq, NULL, &Type, (LPBYTE)rgValue,&size1);
			
		switch ( regStatus ) {
			case ERROR_SUCCESS:
				ndx=0;
				szRgVal=sizeof(rgValue);
	
				for(int i=0;i<szRgVal;i++) {
					szVersion[ndx++]=rgValue[i];
					i++;
				}
	
				maxStr=strlen(szVersion);	
				szVersion[maxStr-0]=(char)'\0';
				printf(" Binary path: %s %i\n", szVersion, strlen(szVersion) );				
								
				RegCloseKey(keyHandle);
				cout << "key was read successfully\n";
				break;

			case ERROR_MORE_DATA:
				cout << "Buffer too small\n";
				break;			

			default:			
				cout << "Count not read key\n";
		}
	}
	else {
		cout << "Can not open key";
		cin.ignore();
	}

	// Free the Memory
	delete [] lpRegPath;

	int strLength = strlen(szVersion);
	wchar_t *szReturnValue = new wchar_t[strLength];
	for (int i = 0; i < strLength; i++) {
		szReturnValue[i] = szVersion[i];
	}
	szReturnValue[ strLength ] = '\0';	
	return szReturnValue;

	delete [] szReturnValue;	
}

WCHAR* CA_Registry::_get_SQLServer_InstalledInstances( void )
{
	HKEY keyHandle;
	WCHAR rgValue[1024];
	WCHAR szInstance[1024];
	CString regPath = L"SOFTWARE\\Microsoft\\Microsoft SQL Server\\";
	CString regReq = L"InstalledInstances";
	DWORD size1 = sizeof(rgValue);
	DWORD Type;
	DWORD dwType = 0;
	DWORD regStatus = REG_MULTI_SZ;

	int ndx;;
	size_t szRgVal;
	int maxStr;
	bool doubleZero;

	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regPath, 0, KEY_QUERY_VALUE, &keyHandle) == ERROR_SUCCESS) {
		dwType = REG_MULTI_SZ;
		regStatus = RegQueryValueEx( keyHandle, regReq, NULL, &Type, (LPBYTE)rgValue, &size1);
			
		switch ( regStatus ) {
			case ERROR_SUCCESS:								
				
				ndx = 0;
                doubleZero = false;
                szRgVal = sizeof(rgValue);
 
                for(int i=0; i < szRgVal; i++) {
                    if (!rgValue[i] == L'\0') {
                        szInstance[ndx++] = rgValue[i];
                        doubleZero = false;
                    }
                    else {
                        if (doubleZero == false) {
                            szInstance[ndx++] = L';';
                            doubleZero = true;
                        }
                        else {
                            szInstance[ndx++] = L'\0\0';
                            break;
                        }
                    }                    
				}

				maxStr = wcslen(szInstance);
                szInstance[maxStr-0] = (char)'\0';
                printf(" SQL Server Instance: %s %i\n", szInstance, wcslen(szInstance) );				
				
				RegCloseKey(keyHandle);
				cout << "key was read successfully\n";
				break;

			case ERROR_MORE_DATA:
				cout << "Buffer too small\n";
				break;			

			default:			
				cout << "Count not read key\n";
		}
	}
	else {
		cout << "Can not open key";
		cin.ignore();
	}
	
	int strSize = sizeof(szInstance);	
	WCHAR *szReturnValue = new wchar_t[strSize];	
	for(int i = 0; i < strSize; i++) {
		szReturnValue[i]=szInstance[i];		
	}	
	strSize=wcslen(szReturnValue);	
	szReturnValue[strSize-0]=(WCHAR)L'\0';

	return szReturnValue;

	delete [] szReturnValue;
}

WCHAR* CA_Registry::_get_SQLServer_InstalledInstances( void )
{
    HKEY keyHandle;
    WCHAR rgValue[1024];
//  WCHAR szInstance[1024]; // not needed
    // no point in using CString for constant strings
    WCHAR* regPath = L"SOFTWARE\\Microsoft\\Microsoft SQL Server\\";
    WCHAR* regReq = L"InstalledInstances";
    DWORD size1 = sizeof(rgValue);
    // Type; removed as no longer used
    // no need to initialise dwType to zero here
    DWORD dwType;
    // no need to initialise regStatus to REG_MULTI_SZ here
    DWORD regStatus;
 
    int ndx;
    WCHAR *szReturnValue = NULL;
/* variables not needed
    size_t szRgVal;
    int maxStr;
    bool doubleZero;
*/ 
    if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regPath, 0, KEY_QUERY_VALUE, &keyHandle) == ERROR_SUCCESS) {
    // no need to initialise dwType to REG_MULTI_SZ here
        regStatus = RegQueryValueEx( keyHandle, regReq, NULL, &dwType, (LPBYTE)rgValue, &size1);
			
        RegCloseKey(keyHandle);	// we're done with the registry so close the key here
        switch ( regStatus ) {
        case ERROR_SUCCESS:								
/*
 * rewrote this part to use standard (Unicode) functions
            ndx = 0;
            doubleZero = false;
            szRgVal = sizeof(rgValue);
 
            for(int i=0; i < szRgVal; i++) {
                if (!rgValue[i] == L'\0') {
                    szInstance[ndx++] = rgValue[i];
                    doubleZero = false;
                }
                else {
                    if (doubleZero == false) {
                        szInstance[ndx++] = L';';
                        doubleZero = true;
                    }
                    else {
                        szInstance[ndx++] = L'\0\0';
                        break;
                    }
                }                    
            }
 */
            // scan the strings, replacing single nulls by semi-colons
            {
                WCHAR* pszString = rgValue;
                while (*pszString)
                {
                    ndx = wcslen(pszString);
                    // add string length so we point at trailing null character
                    pszString += ndx;
                    if (pszString[1] != L'\0')
                    *pszString++ = L';';    // add semi-colon if not the last string
                }
            }
            /* removed this redundant code
            maxStr = wcslen(szInstance);
            szInstance[maxStr-0] = (char)'\0';
            */
            ndx = wcslen(rgValue);	// we need this value below
            // this also needs to be wprintf, as rgValue is Unicode
            wprintf(L" SQL Server Instance: %s %i\n", rgValue, ndx);				
            // following statement is redundant, we already have the printf
            // cout << "key was read successfully\n";

            // copy to new buffer here
            szReturnValue = new wchar_t[ndx + 1]; // +1 for trailing null character
            wcscpy_s(szReturnValue, ndx + 1, rgValue);
            break;
 
        case ERROR_MORE_DATA:
            cout << "Buffer too small\n";
            // your challenge is to fix the code to handle this be allocating a larger buffer
            break;			
 
        default:			
            cout << "Could not read key\n";
        }
    }
    else {
        cout << "Can not open key";
        cin.ignore();
    }
/* moved this functionality to within success case above
    int strSize = sizeof(szInstance);	
    WCHAR *szReturnValue = new wchar_t[strSize];	
        for(int i = 0; i < strSize; i++) {
        szReturnValue[i]=szInstance[i];		    
    }	
    strSize=wcslen(szReturnValue);	
    szReturnValue[strSize-0]=(WCHAR)L'\0';
 */
    return szReturnValue;  // set above
    // this delete statement will never be reached! Also the calling function needs to delete the buffer when finished with it 
//  delete [] szReturnValue;
}