Re: ctypes structure with a variable-size field at the end

gatch breizh schrieb:
> Hi,
> 
> I would like to know how to write a ctypes::Structure with a variable-size
> field at the end.
> It occurs in many protocols to have a data field with a size early defined.
> I have been searching a solution through the web (very usual question) for a
> while but without any success ...
> 
> Attempt #1: Append a new field to the list _fields_ does NOT work...
> <code>
> class LV(Structure):
>   _fields_ = [('Length', c_ushort)]
> 
> lv = LV()
> lv.Length = 5
> lv._fields_.append(('Value', c_ubyte * 5) # ==> added but not usable
> <end of code>
> 
> Attempt #2: use of ctypes.resize() seems to fail for ctypes.Structure
> 
> First, is it possible? if so, how to write it?
> I Hope someone could help me!
> Thanks.
> 
> .: Gatch, Python 2.5.4, CTypes 1.0.3

Do you want to *create* such a structure in Python, or do you want do retrieve
something from such a structure that you received from somewhere?


-- 
Thanks,
Thomas


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