Function RegRead

source/script_registry.cpp:182–347

void RegRead(ResultToken &aResultToken, HKEY aRootKey, LPTSTR aRegSubkey, LPTSTR aValueName, ExprTokenType *aDefault)
{
	HKEY	hRegKey;
	DWORD	dwRes, dwBuf, dwType;
	LONG    result;

	_f_set_retval_p(_T(""), 0); // Set default in case of early return.

	// Open the registry key
	result = RegOpenKeyEx(aRootKey, aRegSubkey, 0, KEY_READ | g->RegView, &hRegKey);
	if (result != ERROR_SUCCESS)
		goto finish_skip_close;

	// Read the value and determine the type.  If aValueName is the empty string, the key's default value is used.
	result = RegQueryValueEx(hRegKey, aValueName, NULL, &dwType, NULL, NULL);
	if (result != ERROR_SUCCESS)
		goto finish;

	LPTSTR contents, cp;

	// The way we read is different depending on the type of the key
	switch (dwType)
	{
		case REG_DWORD:
			dwRes = sizeof(dwBuf);
			result = RegQueryValueEx(hRegKey, aValueName, NULL, NULL, (LPBYTE)&dwBuf, &dwRes);
			if (result == ERROR_SUCCESS)
			{
				// Set the return value but don't return yet.
				aResultToken.Return(dwBuf);
			}
			break;

		// Note: The contents of any of these types can be >64K on NT/2k/XP+ (though that is probably rare):
		case REG_SZ:
		case REG_EXPAND_SZ:
		case REG_MULTI_SZ:
		{
			dwRes = 0; // Retained for backward compatibility because values >64K may cause it to fail on Win95 (unverified, and MSDN implies its value should be ignored for the following call).
			// MSDN: If lpData is NULL, and lpcbData is non-NULL, the function returns ERROR_SUCCESS and stores
			// the size of the data, in bytes, in the variable pointed to by lpcbData.
			result = RegQueryValueEx(hRegKey, aValueName, NULL, NULL, NULL, &dwRes); // Find how large the value is.
			if (result != ERROR_SUCCESS || !dwRes) // Can't find size (realistically might never happen), or size is zero.
				break;
			DWORD dwCharLen = dwRes / sizeof(TCHAR);
			// Set up the result buffer to receive the contents.
			// Since dwRes includes the space for the zero terminator (if the MSDN docs
			// are accurate), this will size it to be 1 byte larger than we need,
			// which leaves room for the final newline character to be inserted after
			// the last item.  But add 2 to the requested capacity in case the data isn't
			// terminated in the registry, which allows double-NULL to be put in for REG_MULTI_SZ later.
			if (!TokenSetResult(aResultToken, NULL, dwCharLen + 2))
				break; // aResultToken.Error() was already called, but we still need to call RegCloseKey().
			//aResultToken.symbol = SYM_STRING; // Already set by _f_set_reval_p().
			contents = aResultToken.marker; // This target buf should now be large enough for the result.

			result = RegQueryValueEx(hRegKey, aValueName, NULL, NULL, (LPBYTE)contents, &dwRes);