static Handle queryRegistryKey(TaskData *taskData, Handle args, HKEY hkey)
{
TCHAR valName[MAX_PATH];
byte *keyValue = 0;
LONG lRes;
DWORD valSize;
Handle result, resVal, resType;
DWORD dwType;
POLYUNSIGNED length = Poly_string_to_C(args->WordP()->Get(1), valName, MAX_PATH);
if (length > MAX_PATH)
raise_syscall(taskData, "Value name too long", ENAMETOOLONG);
// How long is the entry?
lRes = RegQueryValueEx(hkey, valName, 0, NULL, NULL, &valSize);
// When opening HKEY_PERFORMANCE_DATA we don't get a sensible
// answer here.
if (lRes == ERROR_MORE_DATA) valSize = 1024; // Guess
else if (lRes != ERROR_SUCCESS)
raise_syscall(taskData, "RegQueryValueEx failed", -lRes);
// Allocate that much store and get the value. We could
// try reading directly into ML store to save copying but
// it hardly seems worthwhile.
// Note: It seems that valSize can be zero for some items.
if (valSize == 0) resVal = SAVE(Buffer_to_Poly(taskData, "", 0));
else
{
do {
keyValue = (byte*)realloc(keyValue, valSize);
lRes = RegQueryValueEx(hkey, valName, 0, &dwType, keyValue, &valSize);
// In the special case of HKEY_PERFORMANCE_DATA we may need to keep
// growing the buffer.
if (lRes == ERROR_MORE_DATA) valSize = valSize + 1024;
} while (lRes == ERROR_MORE_DATA);
if (lRes != ERROR_SUCCESS)
{
free(keyValue);
raise_syscall(taskData, "RegQueryValue failed", -lRes);
}
resVal = SAVE(Buffer_to_Poly(taskData, (char*)keyValue, valSize));
free(keyValue);
}
/* Create a pair containing the type and the value. */
resType = Make_arbitrary_precision(taskData, dwType);
result = alloc_and_save(taskData, 2);
DEREFHANDLE(result)->Set(0, DEREFWORDHANDLE(resType));
DEREFHANDLE(result)->Set(1, DEREFWORDHANDLE(resVal));
return result;
}
PolyWord C_string_to_Poly(TaskData *mdTaskData, const char *buffer)
/* Returns a C string as a Poly string. */
{
if (buffer == NULL) return EmptyString();
return Buffer_to_Poly(mdTaskData, buffer, strlen(buffer));
} /* C_string_to_Poly */