python多线程实现检测服务器在线情况

#!/usr/bin/python
#coding=utf-8
'''
Created on 2015-8-4
@author: Administrator
'''

import threading,subprocess
from time import ctime,sleep,time
import Queue

queue=Queue.Queue()

class ThreadUrl(threading.Thread):
 def __init__(self,queue):
 threading.Thread.__init__(self)
 self.queue=queue

 def run(self):
 while True:
 host=self.queue.get()
 ret=subprocess.call('ping -c 1 -w 1 '+host,shell=True,stdout=open('/dev/null','w'))
 if ret:
 print "%s is down" % host
 else:
 print "%s is up" % host
 self.queue.task_done()

def main():
 for i in range(100):
 t=ThreadUrl(queue)
 t.setDaemon(True)
 t.start()
 for host in b:
 queue.put(host)
 queue.join()

a=[]
with open('ip.txt') as f:
 for line in f.readlines():
 a.append(line.split()[0])
 #print a

b=['192.168.3.'+str(x) for x in range(1,254)] #ping 192.168.3 网段
start=time()
main()
print "Elasped Time:%s" % (time()-start)

#t2=threading.Thread(target=move,args=('fff',))
#threads.append(t2)

'''
for i in a:
 print ctime()
 ping(i)
 sleep(1)

if __name__ == '__main__':
 for t in range(len(a)):
 #t.setDaemon(True)
 threads[t].start()
 #t.join()
 print "All over %s" % ctime()
'''

#!/usr/bin/python
# encoding=utf-8
# Filename: net_is_normal.py
import os
import socket
import subprocess
 
 
#判断网络是否正常
server='www.baidu.com'
#检测服务器是否能ping通，在程序运行时，会在标准