#!/usr/bin/python
from ctypes import *
from ctypes.util import find_library
import os, platform

xs_transaction_t = c_ulong
struct_xs_handle = c_void_p


xenstore = CDLL(find_library("xenstore"))

xs_read = xenstore.__getattr__("xs_read")
xs_read.argtypes = [ struct_xs_handle, xs_transaction_t, c_char_p, POINTER(c_uint) ]
xs_read.restype = c_char_p

xs_domain_open = xenstore.__getattr__("xs_domain_open")
xs_domain_open.restype = struct_xs_handle

xs_transaction_start = xenstore.__getattr__("xs_transaction_start")
xs_transaction_start.argtypes = [ struct_xs_handle ]
xs_transaction_start.restype = xs_transaction_t

xs_transaction_end = xenstore.__getattr__("xs_transaction_end")
xs_transaction_end.argtypes = [ struct_xs_handle, xs_transaction_t, c_bool ]
xs_transaction_end.restype = c_bool


path = "memory/target"
length = c_uint()
ret = 0
transaction = 0
xsh = None
xst = 0

if transaction:
    xsh = xs_domain_open()
    xst = xs_transaction_start(xsh)

val = xs_read(xsh, xst, path, byref(length))
if val == None:
    ret = 1

if transaction:
    xs_transaction_end(xsh, xth, ret)