ctypes-users — Discussion forum for ctypes users

Re: [ctypes-users] too soon to worry about it

[Michael C <mys...@gm...>]

i understand.

On Mon, Nov 28, 2016 at 7:14 PM, eryk sun <er...@gm...> wrote:

> On Tue, Nov 29, 2016 at 2:53 AM, Michael C
> <mys...@gm...> wrote:
> > I get what you are saying, but not the how-to part. It's ok for me for
> now
> > because I just started last week. :)
>
> Please reply to the original message, without changing the subject
> line. Also, please quote the message to which you're replying.
> Otherwise there's no threading and no context. This isn't a chat room.
>
> Gmail probably won't reply to the list unless you select "Reply to
> all" from the drop-down menu.
>

Re: [ctypes-users] too soon to worry about it

[eryk s. <er...@gm...>]

On Tue, Nov 29, 2016 at 2:53 AM, Michael C
<mys...@gm...> wrote:
> I get what you are saying, but not the how-to part. It's ok for me for now
> because I just started last week. :)

Please reply to the original message, without changing the subject
line. Also, please quote the message to which you're replying.
Otherwise there's no threading and no context. This isn't a chat room.

Gmail probably won't reply to the list unless you select "Reply to
all" from the drop-down menu.

[ctypes-users] creating a Ctypes.windll.user32.sendinput command

[Michael C <mys...@gm...>]

Hi all:
I am trying to create a combined sendinput function with holding down right
mouse button, moving the mouse, and releasing the mouse button inside ONE
sendinput functon. Here is my current code:


import ctypes

INPUT mouseinput

input.type = INPUT_MOUSE
input.mi.dx = 0
input.mi.dy = 0
input.mi.dwFlags = MOUSEEVENTF_RIGHTDOWN
input.mi.time = 10
input.mi.time = 0


#Sleep(50);
input.type = INPUT_MOUSE
input.mi.dx = 100
input.mi.dy = 0
input.mi.dwFlags = MOUSEEVENTF_MOVE
input.mi.time = 10


#Sleep(50);
input.type = INPUT_MOUSE
input.mi.dx = 0
input.mi.dy = 0
input.mi.dwFlags = MOUSEEVENTF_RIGHTUP
input.mi.time = 0


SendInput(3, &input, sizeof(input));



This part by itself pops a syntax error:

import ctypes
INPUT mouseinput

How do I create an array of this type?
https://msdn.microsoft.com/en-us/library/windows/desktop/ms646310(v=vs.85).aspxhttps://msdn.microsoft.com/en-us/library/windows/desktop/ms646270(v=vs.85).aspx

thx all!

[ctypes-users] too soon to worry about it

[Michael C <mys...@gm...>]

I get what you are saying, but not the how-to part. It's ok for me for now
because I just started last week. :)

Re: [ctypes-users] windll

[eryk s. <er...@gm...>]

On Mon, Nov 28, 2016 at 5:08 PM, Michael C
<mys...@gm...> wrote:
> sorry I am new to this thing, I guess what I mean is I am looking for a list
> of every functions and classes available under ctypes, as seen here:
>
> http://nullege.com/codes/search/ctypes.windll.user32.SetWindowPos
>
> a complete list everything and a description for them,
>
> Is there something like that? especially for windll,

Actually, please avoid using cdll and windll. These global
LibraryLoader instances weren't a good idea. They cache CDLL and
WinDLL instances when accessed as attributes (e.g. windll.user32),
which cache function pointers. This leads to definition conflicts
between libraries that use the same DLL and define function prototypes
(i.e. restype, argtypes, errcheck), which is especially problematic
for common CRT and Windows API functions.

Use CDLL and WinDLL directly. I also recommend passing
use_last_error=True to WinDLL, e.g. user32 = ctypes.WinDLL('user32',
use_last_error=True) . This calls SetLastError and GetLastError around
each library function call, to set and get a thread-local value that's
more reliable in Python. You can get and set this thread-local value
via ctypes.get_last_error and ctypes.set_last_error.

[ctypes-users] also thx guys for the previous problem

[Michael C <mys...@gm...>]

I didn't know about the MSDN library, thanks a lot, people.

[ctypes-users] python memory scanner - is it ok to ask you guys about it?

[Michael C <mys...@gm...>]

I have this code here I am working on. Right now it has 3 problems and then
I still don't know if it works:

what type of buffer should I create?

buff = ctypes.create_string_buffer(4) I am not sure what sort of buffer
ReadProcessMemory expect, and LPVOID, from MSDN,
https://msdn.microsoft.com/en-us/library/windows/desktop/ms680553(v=vs.85).aspx

doens't ring a bell for me.

2ndly,

what's the number I should use here?

addresses_list = range(????,????,???)

I am not sure how memory spaces are named, does each program get its own
memory space? So do I put down 99999999?

3rdly, I believe I configured unpack incorrectly, as I don't understand
what sort of parameters to give because I don't understand how the memory
works.

Basically my goal is to write a memory scanner so I'd better understand how
memories work.



import ctypes
from ctypes import wintypes as w
from struct import *
from time import *
import datetime
import sys
import time

PID = 15872

OpenProcess = ctypes.windll.kernel32.OpenProcess
OpenProcess.argtypes = [w.DWORD,w.BOOL,w.DWORD]
OpenProcess.restype = w.HANDLE

ReadProcessMemory = ctypes.windll.kernel32.ReadProcessMemory
ReadProcessMemory.argtypes = [w.HANDLE,w.LPCVOID,w.LPVOID,

ctypes.c_size_t,ctypes.POINTER(ctypes.c_size_t)]
ReadProcessMemory.restype = w.BOOL

PROCESS_QUERY_INFORMATION = 0x0400
PROCESS_VM_READ = 0x0010

ph = OpenProcess(PROCESS_QUERY_INFORMATION|PROCESS_VM_READ,False,int(PID))
#program handle

#this is a problem: what type of buffer should I create?
buff = ctypes.create_string_buffer(4)
bufferSize = ctypes.sizeof(buff)
bytesRead = ctypes.c_size_t(bufferSize)

# what's the number I should use here?
#addresses_list = range(0x99999999999)

address = 0x4000000
addresses_list = range(address,0x9000000,0x4)

for i in addresses_list:
    ReadProcessMemory(ph, ctypes.c_void_p(i), buff, bufferSize,
ctypes.byref(bytesRead))
    # I am uncertain how to configure unpack
    print(buff)
    value = unpack('I', buff)[0]
    if value == int(64953):
        print(i)

[ctypes-users] got it

[Michael C <mys...@gm...>]

https://msdn.microsoft.com/en-us/library/windows/desktop/ms684320(v=vs.85).aspx

thx all

[ctypes-users] python memory scanner

[Michael C <mys...@gm...>]

hi all:
   i am trying to write a memory scanner in python, nothing fancy and I
know I am new but if it's only this long

http://stackoverflow.com/questions/28672271/writing-memory-scanner-in-python

then I can understand it within a week or so, if i do it slowly.

[ctypes-users] oh i am trying to convert from c++

[Michael C <mys...@gm...>]

oh I am trying to convert my pet project from c++, that's why.
Also, I used only 2 lines of code to move windows around, so i am fine now
with it now that i have the API reference.

Re: [ctypes-users] ctypes reference book

[Rob G. <rg...@hi...>]

Michael, I think you may have gotten wrapped around the axle a bit. USER32.DLL is one of the core DLLs of the Windows system, been around since at least Windows 3.0.  When you talk about windll.user32, that's just ctypes accessing that library, and looks the same as the ctypes interface to any library. 

That said, if I recall correctly, most what happens in there is GUI management. If that's what you're trying to do, you almost certainly want to use one of the many GUI toolkits available for Python rather than try to bang against the DLL yourself. 

On November 28, 2016 8:06:33 AM GMT-07:00, "Diez B. Roggisch" <de...@we...> wrote:
>I don’t understand your inquiry.
>
>Everything relevant to ctypes is in the first link of yours. What are
>you missing there?
>
>Your second link talks about a specific windows DLL and it’s
>functionality. Do you expect ctypes to contain documentation for
>*arbirtrary* libraries out there? That’s quite impossible. You will
>need to look at the DLL in question (or better it’s documentation), and
>learn from that how to use it through ctypes.
>
>Diez
>
>> On 28 Nov 2016, at 03:33, Michael C <mys...@gm...>
>wrote:
>> 
>> Sorry guys, but I can't find the reference book of ctypes, and I am
>looking for everythign there is under ctype.user32
>> 
>> I have this already
>> 
>> https://docs.python.org/3/library/ctypes.html#ctypes.WinDLL
><https://docs.python.org/3/library/ctypes.html#ctypes.WinDLL>
>> 
>> the best I can find to what I am describing to you is this:
>> 
>>
>http://nullege.com/codes/show/src@m@o@mozharness-HEAD@external_tools@mouse_and_screen_resolution.py/115/ctypes.windll.user32.GetCursorPos
><http://nullege.com/codes/show/src@m@o@mozharness-HEAD@external_tools@mouse_and_screen_resolution.py/115/ctypes.windll.user32.GetCursorPos>
>> 
>> 
>> 
>> I need everything there is to know about the ctypes. Yes I googled
>for it.
>> 
>> thanks!
>>
>------------------------------------------------------------------------------
>> _______________________________________________
>> ctypes-users mailing list
>> cty...@li...
>> https://lists.sourceforge.net/lists/listinfo/ctypes-users
>
>
>
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Sent from my Android device with K-9 Mail. Please excuse my brevity.

[ctypes-users] kernel 32?

[Michael C <mys...@gm...>]

how about windll.kernel32?

[ctypes-users] oh i see

[Michael C <mys...@gm...>]

thanks!!! I didnt know that

Re: [ctypes-users] windll

[Mark L. <lar...@gm...>]

Michael,

You aren't understanding.  ctypes doesn't provide these functions.  It's
Python module that allows you to call C functions exposed in DLLs
(externed).  The functions are you interested are provided by the Windows
operating system.  These are commonly referred to as win32 functions.  They
are very well documented on MSDN.  For instance, the documentation for the
functions under User32.dll are located here:
https://msdn.microsoft.com/en-us/library/windows/desktop/ff468919(v=vs.85).aspx

Another great resource is http://www.pinvoke.net/.  While that is geared
toward .NET's implementation of a cytpes like library (interop services),
the function definitions are the same.

Thanks,
Mark



On Mon, Nov 28, 2016 at 12:12 PM, Michael C <mys...@gm...>
wrote:

> googling python windll returns python ctypes. i dont understand how the
> documentation works for this thing. :(
>
> ------------------------------------------------------------
> ------------------
>
> _______________________________________________
> ctypes-users mailing list
> cty...@li...
> https://lists.sourceforge.net/lists/listinfo/ctypes-users
>
>

[ctypes-users] windll

[Michael C <mys...@gm...>]

googling python windll returns python ctypes. i dont understand how the
documentation works for this thing. :(

[ctypes-users] windll

[Michael C <mys...@gm...>]

sorry I am new to this thing, I guess what I mean is I am looking for a
list of every functions and classes available under ctypes, as seen here:

http://nullege.com/codes/search/ctypes.windll.user32.SetWindowPos

a complete list everything and a description for them,

Is there something like that? especially for windll,

sorry for being a noob

Re: [ctypes-users] ctypes reference book

[Diez B. R. <de...@we...>]

I don’t understand your inquiry.

Everything relevant to ctypes is in the first link of yours. What are you missing there?

Your second link talks about a specific windows DLL and it’s functionality. Do you expect ctypes to contain documentation for *arbirtrary* libraries out there? That’s quite impossible. You will need to look at the DLL in question (or better it’s documentation), and learn from that how to use it through ctypes.

Diez

> On 28 Nov 2016, at 03:33, Michael C <mys...@gm...> wrote:
> 
> Sorry guys, but I can't find the reference book of ctypes, and I am looking for everythign there is under ctype.user32
> 
> I have this already
> 
> https://docs.python.org/3/library/ctypes.html#ctypes.WinDLL <https://docs.python.org/3/library/ctypes.html#ctypes.WinDLL>
> 
> the best I can find to what I am describing to you is this:
> 
> http://nullege.com/codes/show/src@m@o@mozharness-HEAD@external_tools@mouse_and_screen_resolution.py/115/ctypes.windll.user32.GetCursorPos <http://nullege.com/codes/show/src@m@o@mozharness-HEAD@external_tools@mouse_and_screen_resolution.py/115/ctypes.windll.user32.GetCursorPos>
> 
> 
> 
> I need everything there is to know about the ctypes. Yes I googled for it.
> 
> thanks!
> ------------------------------------------------------------------------------
> _______________________________________________
> ctypes-users mailing list
> cty...@li...
> https://lists.sourceforge.net/lists/listinfo/ctypes-users

[ctypes-users] ctypes reference book

[Michael C <mys...@gm...>]

Sorry guys, but I can't find the reference book of ctypes, and I am looking
for everythign there is under ctype.user32

I have this already

https://docs.python.org/3/library/ctypes.html#ctypes.WinDLL

the best I can find to what I am describing to you is this:

http://nullege.com/codes/show/src@m@o@mozharness-HEAD@external_tools@mouse_and_screen_resolution.py/115/ctypes.windll.user32.GetCursorPos



I need everything there is to know about the ctypes. Yes I googled for it.

thanks!

Re: [ctypes-users] callbacks and threading

[Diez B. R. <de...@we...>]

It is not possible for ctypes (or anything else, for that matter) to force a running thread to execute arbitrary other code, and the just jump back to execution.

I see two options that need investigation:

 - currentThread is for whatever reason confused. You could try that out by making your callback stall for several seconds (time.sleep), and observe if the mainloop is still running.
 - the mainloop you describe is an actual eventloop, in which case the design of your application needs to be altered. For this we would need to see more code.

So - which is it?

Diez


> On 19 Aug 2016, at 23:44, KP <pat...@gm...> wrote:
> 
> I have a python client with ctypes wrappers to call in to a DLL that in turn talks to a server process. One of the features is to register a callback on an event. I am able to successfully register callbacks, and they do get called on events...so all is working well there.
> 
> However, it seems the callbacks are always executed in the "main" thread...even when I know there are other commands running in the main thread.
> 
> I'm not entirely sure how this happens/or is possible.  The main thread is running a loop, but the callback also reports being in the main thread (by printing threading.currentThread()). Is this something ctypes has control over that I can tweak?
> 
> I need it to be in a different thread so that any CTRL-C will _not_ end up in that thread, and will instead impact the main thread...er, well, what I am thinking of as the main thread (not the callback).
> 
> Any ideas? Thanks,
> Kevin
> ------------------------------------------------------------------------------
> _______________________________________________
> ctypes-users mailing list
> cty...@li...
> https://lists.sourceforge.net/lists/listinfo/ctypes-users

[ctypes-users] callbacks and threading

[KP <pat...@gm...>]

I have a python client with ctypes wrappers to call in to a DLL that in
turn talks to a server process. One of the features is to register a
callback on an event. I am able to successfully register callbacks, and
they do get called on events...so all is working well there.

However, it seems the callbacks are always executed in the "main"
thread...even when I know there are other commands running in the main
thread.

I'm not entirely sure how this happens/or is possible.  The main thread is
running a loop, but the callback also reports being in the main thread (by
printing threading.currentThread()). Is this something ctypes has control
over that I can tweak?

I need it to be in a different thread so that any CTRL-C will _not_ end up
in that thread, and will instead impact the main thread...er, well, what I
am thinking of as the main thread (not the callback).

Any ideas? Thanks,
Kevin

Re: [ctypes-users] Loading a dll file on a Unix computer

[Diez B. R. <de...@we...>]

Hi,

while the error-message looks like it could be a path-problem for now, eventually this is bound to fail - you can’t use DLLs built for windows under Unix. At least not just like this.

If you can’t use windows, you could try WINE & a Windows-Python. No idea how easy/good that works though.

Diez


> On 18 Jul 2016, at 21:26, kristine l <per...@gm...> wrote:
> 
> Hi guys!
> 
> I am trying to load the '__CLDevIFace.dll' library found on this page:
> 
> https://github.com/charlie1kimo/Zygo/tree/master/wave_meter_wrapper <https://github.com/charlie1kimo/Zygo/tree/master/wave_meter_wrapper>
> 
> to communicate with a Bristol 621 wavemeter. I would be doing this on a Unix computer, and each time I try to run:
> 
> """
> from ctypes import *
> dll = cdll.LoadLibrary('__CLDevIFace.dll')
> """
> 
> It gives me the error:
> 
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/usr/lib/python2.7/ctypes/__init__.py", line 443, in LoadLibrary
>     return self._dlltype(name)
>   File "/usr/lib/python2.7/ctypes/__init__.py", line 365, in __init__
>     self._handle = _dlopen(self._name, mode)
> OSError: __CLDevIFace.dll: cannot open shared object file: No such file or directory
> 
> 
> 
> I have no idea where to go from here, and the tutorial on the ctypes package is not helping me.
> 
> Thanks for any help!
> ------------------------------------------------------------------------------
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[ctypes-users] Loading a dll file on a Unix computer

[kristine l <per...@gm...>]

Hi guys!

I am trying to load the '__CLDevIFace.dll' library found on this page:

https://github.com/charlie1kimo/Zygo/tree/master/wave_meter_wrapper

to communicate with a Bristol 621 wavemeter. I would be doing this on a
Unix computer, and each time I try to run:

"""
from ctypes import *
dll = cdll.LoadLibrary('__CLDevIFace.dll')
"""

It gives me the error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/ctypes/__init__.py", line 443, in LoadLibrary
    return self._dlltype(name)
  File "/usr/lib/python2.7/ctypes/__init__.py", line 365, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: __CLDevIFace.dll: cannot open shared object file: No such file or
directory



I have no idea where to go from here, and the tutorial on the ctypes
package is not helping me.

Thanks for any help!

Re: [ctypes-users] Using ctypes inside a C application embedding the CPython runtime

[eryk s. <er...@gm...>]

On Thu, Jun 16, 2016 at 4:43 AM, jef...@gm...
<jef...@gm...> wrote:
>
> I just created the issue[0] and will start reading the documentation to
> create and submit the patch.

Thank you.

Re: [ctypes-users] Using ctypes inside a C application embedding the CPython runtime

[<jef...@gm...>]

Hi Eryk,

On Thu, Jun 9, 2016 at 1:09 PM, eryk sun <er...@gm...> wrote:

> On Thu, Jun 9, 2016 at 4:35 PM, jef...@gm...
> <jef...@gm...> wrote:
> >
> > Great to read that! Is there any way I can help to get this documented?
> > Should I submit a PR to the documentation or something like that?
>
> Here's the link to create a new issue:
>
>     http://bugs.python.org/issue?@template=item
>
> It's an enhancement for components "ctypes" and "Documentation" for
> 2.7, 3.5, and 3.6. See the dev guide for how to get started with
> submitting patches and writing docs using reStructuredText.
>
>     https://docs.python.org/devguide
>


I just created the issue[0] and will start reading the documentation to
create and submit the patch.


Thank you very much,

[0] http://bugs.python.org/issue27329

-- 
Jeffrey Esquivel S.

Re: [ctypes-users] Pickling ctypes pointer/array

[Carlos P. <car...@gm...>]

>
> bytearray's __reduce_ex__ creates a bytes copy in the args tuple (see
> _common_reduce in Objects/bytearrayobject.c):
>
>
Oh, I see, it seems that all hope is lost until someone makes memoryviews
picklable, then. But it's not that clear how memoryviews would reconstruct
their dumps at load-side, anyway, since they are just views to proper
objects.

Thank you again
--
Carlos