问一个自动释放的问题

QUOTE:

#!/usr/bin/env python

from socket import socket, AF_INET, SOCK_DGRAM
from fcntl import ioctl
from array import array
from struct import pack, unpack

SIOCGIFCONF=0x8912

def interface_list():
    buf=array('B', '\0'*4096)
    s=socket(AF_INET, SOCK_DGRAM)

    n=unpack(
        'iL',
        ioctl(s.fileno(), SIOCGIFCONF,
              pack('iL', *buf.buffer_info()[::-1])))[0]

    names=buf.tostring()
    return map(lambda x:(names[x:x+16]).split('\0',1)[0], range(0, n, 40))
   

print interface_list()