Re: Acquiring process handle and convert it into PID

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I get it now! Reading MSDN is a merit on its own!

So this is the same thing right?

thx!


import ctypes
import time

time.sleep(2)

user32 = ctypes.WinDLL('user32', use_last_error=True)
hwnd = user32.GetForegroundWindow()

# this part
pid = ctypes.c_ulong()

user32.GetWindowThreadProcessId(hwnd, ctypes.byref(pid))
print(pid.value)

On Wed, Nov 30, 2016 at 8:56 AM, eryk sun <[email protected]> wrote:

> On Wed, Nov 30, 2016 at 4:33 PM, Michael C
> <[email protected]> wrote:
> > Sorry for asking about this over and over again.
> >
> > I ran the code at the bottom and got a
> >
> > user32.GetWindowThreadProcessId(handle, PID)
> > OSError: exception: access violation writing 0x00000001
> >
> > import ctypes
> > import time
> >
> > time.sleep(2)
> > user32 = ctypes.WinDLL('user32', use_last_error=True)
> > handle = user32.GetForegroundWindow()
> > print(handle)
> > PID = 1
> > user32.GetWindowThreadProcessId(handle, PID)
> > print (PID)
>
> Let's review the prototype:
>
>     DWORD WINAPI GetWindowThreadProcessId(
>       _In_      HWND    hWnd,
>       _Out_opt_ LPDWORD lpdwProcessId);
>
> lpdwProcessId is an LPDWORD. The LP stands for "long pointer". (Ignore
> the "long" part since it's a vestige of older CPU architectures.) You
> need to pass a pointer to a DWORD. That's a C unsigned long integer,
> so you can use ctypes.c_ulong(). Or use the wintypes module, which
> defines most of the common Windows data types. To pass a pointer you
> can use ctypes.byref. For example:
>
>     import ctypes
>     from ctypes import wintypes
>
>     user32 = ctypes.WinDLL('user32', use_last_error=True)
>
>     hwnd = user32.GetForegroundWindow()
>     pid = wintypes.DWORD()
>     user32.GetWindowThreadProcessId(hwnd, ctypes.byref(pid))
>
> The process ID is in the `value` attribute:
>
>     >>> pid.value
>     4832
>

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<div dir=3D"ltr">I get it now! Reading MSDN is a merit on its own!<div><br>=
</div><div>So this is the same thing right?</div><div><br></div><div>thx!</=
div><div><br></div><div><br></div><div><div>import ctypes</div><div>import =
time</div><div><br></div><div>time.sleep(2)</div><div><br></div><div>user32=
 =3D ctypes.WinDLL(&#39;user32&#39;, use_last_error=3DTrue)</div><div>hwnd =
=3D user32.GetForegroundWindow()</div><div><br></div><div># this part</div>=
<div>pid =3D ctypes.c_ulong()</div><div><br></div><div>user32.GetWindowThre=
adProcessId(hwnd, ctypes.byref(pid))</div><div>print(pid.value)</div></div>=
</div><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">On Wed, Nov=
 30, 2016 at 8:56 AM, eryk sun <span dir=3D"ltr">&lt;<a href=3D"mailto:eryk=
[email protected]" target=3D"_blank">[email protected]</a>&gt;</span> wrote:<br=
><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1=
px #ccc solid;padding-left:1ex"><span class=3D"">On Wed, Nov 30, 2016 at 4:=
33 PM, Michael C<br>
&lt;<a href=3D"mailto:[email protected]">mysecretrobotfactory@=
gmail.<wbr>com</a>&gt; wrote:<br>
&gt; Sorry for asking about this over and over again.<br>
&gt;<br>
&gt; I ran the code at the bottom and got a<br>
&gt;<br>
&gt; user32.<wbr>GetWindowThreadProcessId(<wbr>handle, PID)<br>
&gt; OSError: exception: access violation writing 0x00000001<br>
&gt;<br>
&gt; import ctypes<br>
&gt; import time<br>
&gt;<br>
&gt; time.sleep(2)<br>
&gt; user32 =3D ctypes.WinDLL(&#39;user32&#39;, use_last_error=3DTrue)<br>
&gt; handle =3D user32.GetForegroundWindow()<br>
&gt; print(handle)<br>
&gt; PID =3D 1<br>
&gt; user32.<wbr>GetWindowThreadProcessId(<wbr>handle, PID)<br>
&gt; print (PID)<br>
<br>
</span>Let&#39;s review the prototype:<br>
<br>
=C2=A0 =C2=A0 DWORD WINAPI GetWindowThreadProcessId(<br>
=C2=A0 =C2=A0 =C2=A0 _In_=C2=A0 =C2=A0 =C2=A0 HWND=C2=A0 =C2=A0 hWnd,<br>
=C2=A0 =C2=A0 =C2=A0 _Out_opt_ LPDWORD lpdwProcessId);<br>
<br>
lpdwProcessId is an LPDWORD. The LP stands for &quot;long pointer&quot;. (I=
gnore<br>
the &quot;long&quot; part since it&#39;s a vestige of older CPU architectur=
es.) You<br>
need to pass a pointer to a DWORD. That&#39;s a C unsigned long integer,<br=
>
so you can use ctypes.c_ulong(). Or use the wintypes module, which<br>
defines most of the common Windows data types. To pass a pointer you<br>
can use ctypes.byref. For example:<br>
<br>
=C2=A0 =C2=A0 import ctypes<br>
=C2=A0 =C2=A0 from ctypes import wintypes<br>
<span class=3D""><br>
=C2=A0 =C2=A0 user32 =3D ctypes.WinDLL(&#39;user32&#39;, use_last_error=3DT=
rue)<br>
<br>
</span>=C2=A0 =C2=A0 hwnd =3D user32.GetForegroundWindow()<br>
=C2=A0 =C2=A0 pid =3D wintypes.DWORD()<br>
=C2=A0 =C2=A0 user32.<wbr>GetWindowThreadProcessId(hwnd, ctypes.byref(pid))=
<br>
<br>
The process ID is in the `value` attribute:<br>
<br>
=C2=A0 =C2=A0 &gt;&gt;&gt; pid.value<br>
=C2=A0 =C2=A0 4832<br>
</blockquote></div><br></div>

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