ctypes question

MrJean1 mrjean1 at gmail.com
Tue Dec 14 19:47:05 EST 2010


Try again after changing line 16 to

  sn = SmiGetNode(None, "1.3.6.1.2.1.2.2")

Because, SmiGetNode is a Python function which accepts Python objects
as arguments.  Passing is a ctypes object oid is incorrect.

/Jean


On Dec 14, 10:36 am, News Wombat <newswom... at gmail.com> wrote:
> On Dec 11, 12:59 pm, MrJean1 <mrje... at gmail.com> wrote:
>
> > In general, for shared libraries, you need to define those first as
> > prototype using ctypes.CFUNCTYPE() and then instantiate each prototype
> > once supplying the necessary parameter flags using
> > prototype(func_spec, tuple_of_param_flags).  See sections 15.16.2.3
> > and 4 of the ctypes docs*.
>
> I tried the cfuntype and proto steps, and it's not crashing now
> (that's good), but now i'm just left with null pointers as a return
> object.  I'm still working through all of the examples you sent.  They
> were extremely helpful.  Here's where I'm at now...
>
> What is strange is I can actually get smiGetNode to work if I don't
> cfunctype/proto it.  If i do, nada.  however, the smiGetNextNode fails
> no matter what, usually with a segfault, but depending on how i
> construct it, sometimes a null pointer.
>
> constants.py:http://pastebin.com/f3b4Wbf0
> libsmi.py:http://pastebin.com/XgtpG6gr
> smi.c (the actual function):http://pastebin.com/Pu2vabWM




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