ctypes pointer to pointer

[Podi]

Hi,

I have a C function in the dll does the following:

DLL_API int dll_foo(char **data, size_t *size)
{
    strcpy(*data, "hello");
    *size = strlen(*data);

    return 0;
}


So I would call the function as such,

char data[8];
size_t size;

int status = dll_foo(&data, &size);

I have tried the following in Python but not able to get it working...
Any help would be appreciated!

from ctypes import *
mydll = windll.mydll
array = c_char * 8
data = array()
size = c_long()
status = mydll.dll_foo(byref(data), byref(size))
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
WindowsError: exception: access violation writing 0x00000000


mydll.dll_foo(POINTER(data), byref(size))
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
  File "C:\Python24\Lib\site-packages\ctypes\__init__.py", line 197, in
POINTER
    return _pointer_type_cache[cls]
TypeError: unhashable type

out = c_char_p(data.raw)
mydll.dll_foo(byref(out), byref(size))
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
ValueError: Procedure probably called with too many arguments (8 bytes
in excess)

mydll..dll_foo(out, byref(size))
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
WindowsError: exception: access violation writing 0x6C6C6568

temp = create_string_buffer('\000' * 32)
mydll.dll_foo(temp, byref(size))
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
WindowsError: exception: access violation writing 0x00000000

mydll.dll_foo(byref(temp), byref(size))
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
WindowsError: exception: access violation writing 0x00000000