ntp_client.py

ntp的客户端代码 可以返回ntp server的时间

from socket import *   
import struct,os,time,sys   
  
# Script to set Linux hardware clock (/usr/sbin/hwclock) from an NTP   
# time server.   Run as "setclock.py" to simply print the time from   
# the NTP server.  Run as "setclock.py --set" to set the Linux   
# hardware clock (as the super user, of course).   
  
# Based on Simon Foster's simple SNTP client from ASPN Python cookbook.   
# Adapted by Paul Rubin; this script lives at:   
#    http://www.nightsong.com/phr/python/setclock.py   
  
time_server = ('time.apple.com', 123)   
# time.apple.com is a stratum 2 time server.  (123 is the SNTP port number).   
# More servers info can be found at   
#   
#   http://www.eecis.udel.edu/~mills/ntp/servers.htm   
#   
# Note it's considered antisocial to use a stratum 1 server (like NIST)   
# for purposes like this which don't need extreme accuracy (i.e. syncing   
# your own big NTP network).  See www.ntp.org for more info.   
#   
# You could also use time.windows.com (Microsoft server) which syncs   
# all Windows XP machines everywhere, so it can presumably handle lots   
# of clients.   
  
# number of seconds between NTP epoch (1900) and Unix epoch (1970).   
TIME1970 = 2208988800L      # Thanks to F.Lundh   
  
client = socket( AF_INET, SOCK_DGRAM )   
data = '\x1b' + 47 * '\0'  
client.sendto(data, time_server)   
data, address = client.recvfrom( 1024 )   
if data:   
    print 'Response received from', address,'\n'  
    t = struct.unpack( '!12I', data )[10]   
    if t == 0:   
        raise 'invalid response'  
    ct = time.ctime(t - TIME1970)   
    print 'Current time = %s\n' % ct   
    if len(sys.argv) > 1 and sys.argv[1] == "--set":   
        os.system("/usr/sbin/hwclock --set '--date=%s'"% ct)   
else:   
    raise 'no data returned'