#!/usr/bin/env python

from ctypes import *

qsort = CDLL("libc.so.6").qsort
qsort.restype = None

class CmpRet(c_int):
    pass

cmp_ctype = CFUNCTYPE(CmpRet, POINTER(c_int), POINTER(c_int))

IntArray5 = c_int * 2
ia = IntArray5(5, 1)

CMP_EQ = CmpRet(0)


def py_cmp_func(a, b):
    print(a.contents, b.contents)
    return CMP_EQ

cmp_fun = cmp_ctype(py_cmp_func)
qsort.argtypes = [IntArray5, c_size_t, c_int, cmp_ctype]

qsort(ia, len(ia), sizeof(c_int), cmp_fun)