Question

What im doing wrong this time? The following code always returns 4 bytes only, instead of the whole string:

HKEY hkey;
DWORD dwType, dwSize;

char keybuffer[512];

if(RegOpenKeyEx(HKEY_CURRENT_USER, TEXT("software\\company name\\game name"), 0, KEY_READ, &hkey) == ERROR_SUCCESS){
    dwType = REG_SZ;
    dwSize = sizeof(keybuffer);
    RegQueryValueEx(hkey, TEXT("setting"), NULL, &dwType, (PBYTE)&keybuffer, &dwSize);
    RegCloseKey(hkey);
}

Even if i change dwSize to anything, it will still return 4 bytes.

Edit: Apparently there was no bug in above code, but somewhere else -_-

Answer 1

I see two more potential pitfalls here. First, as Francis mentioned, you should check the return value. Do the 4 bytes actually correspond to the string characters you expect? They might be anything. From the documentation:

If the buffer specified by lpData parameter is not large enough to hold the data, the function returns ERROR_MORE_DATA and stores the required buffer size in the variable pointed to by lpcbData. In this case, the contents of the lpData buffer are undefined.

The second potential pitfall is that you’re using a char array with a function that takes TCHAR parameters. If you’re compiling for Unicode, the compiler will happily let you write a wide string to your narrow string buffer, due to the cast to PBYTE. It’s safer to either use TCHAR consistently or don’t use it at all (i.e. call RegQueryValueExA or RegQueryValueExW).