ioctl, pass buffer address, howto?

[Gabriel Genellina]

En Fri, 25 Apr 2008 09:30:56 -0300, Neal Becker <ndbecker2 at gmail.com>  
escribió:

> I need an ioctl call equivalent to this C code:
>
>     my_struct s;
>     s.p = p; << a pointer to an array of char
>     s.image_size = image_size;
>     return (ioctl(fd, xxx, &s));
>
> I'm thinking to use python array for the array of char, but I don't see  
> how
> to put it's address into the structure.

Use the array's buffer_info() method:
"""buffer_info(): Return a tuple (address, length) giving the current  
memory address and the length in elements of the buffer used to hold  
array's contents."""
<http://docs.python.org/lib/module-array.html>
and you can use the struct module to build my_struct.

> Maybe ctypes is the answer?

It could be used too, but I think that in this case it's harder to use  
ctypes.

-- 
Gabriel Genellina