Re: in_dll string assignment question

"Ben Stroud" <[email protected]> wrote in message 
news:[email protected]...
>I could use some help assigning to global C variable in DLL using ctypes.
>
> test.c contains the following
>
> #include <stdio.h>
>
> char name[60];
> void test(void) {
> printf("Name is %s\n", name);
> }
>
>
> On windows (cygwin) I build a DLL (test.dll) as follows:
>
> gcc -g -c -Wall test.c
> gcc -Wall -mrtd -mno-cygwin -shared -W1,--add-stdcall-alias -o Test.dll
> test.o
>
> Then when trying to modify the `name` variable and then calling the C
> test function using the ctypes interface I get the following...
>
> >>> from ctypes import *
> >>> dll = windll.Test
> >>> dll
> <WinDLL 'Test', handle ... at ...>
> >>> f = c_char_p.in_dll(dll, 'name')
> >>> f
> c_char_p(None)
> >>> f.value = 'foo'
> >>> f
> c_char_p('foo')
> >>> dll.test()
> Name is Name is 4∞┘☺
> 13
>
> Why does the test function print garbage in this case?

"name" is an array, not a pointer.  Try:

    (c_char*60).in_dll(dll,'name').value = "foo"

-Mark



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