Python检查和同步本地时间(北京时间)的实现方法

# -*- coding: utf-8
 
import sys
import time
import subprocess
import argparse
import urllib2
 
 
def set_beijing_time_from_web(url):
 \'\'\' set os and hardware clock as beijing time from internet \'\'\'
 # use urllib2 in python2; not use requests which need installation
 response = urllib2.urlopen(url)
 #print response.read()
 # 获取http头date部分
 ts = response.headers[\'date\']
 # 将日期时间字符转化为time
 gmt_time = time.strptime(ts[5:25], \"%d %b %Y %H:%M:%S\")
 # 将GMT时间转换成北京时间
 local_time = time.localtime(time.mktime(gmt_time) + 8*3600)
 str1 = \"%u-%02u-%02u\" % (local_time.tm_year,
        local_time.tm_mon, local_time.tm_mday)
 str2 = \"%02u:%02u:%02u\" % (
  local_time.tm_hour, local_time.tm_min, local_time.tm_sec)
 cmd = \'date -s \"%s %s\"\' % (str1, str2)
 #print cmd
 subprocess.check_call(cmd, shell=True)
 hw_cmd = \'hwclock -w\'
 #print hw_cmd
 subprocess.check_call(hw_cmd, shell=True)
 print \'OK. set time: %s\' % \' \'.join([str1, str2])
 
 
def check_localtime_with_internet(url):
 \'\'\' check local time with internet \'\'\'
 threshold = 2
 # use urllib2 in python2; not use requests which need installation
 response = urllib2.urlopen(url)
 #print response.read()
 # 获取http头date部分
 ts = response.headers[\'date\']
 # 将日期时间字符转化为time
 gmt_time = time.strptime(ts[5:25], \"%d %b %Y %H:%M:%S\")
 # 将GMT时间转换成北京时间
 internet_ts = time.mktime(gmt_time)
 local_ts = time.mktime(time.gmtime())
 if abs(local_ts - internet_ts) <= threshold:
  print \'OK. check localtime.\'
 else:
  print \'ERROR! local_ts: %s internet_ts:%s\' % (local_ts, internet_ts)
  sys.exit(1)
 
 
if __name__ == \'__main__\':
 url = \'http://www.baidu.com\'
 parser = argparse.ArgumentParser()
 parser.de ion = \'set/check localtime (i.e. CST) with internet\'
 parser.add_argument(\'-c\', \'--check\', action=\'store_true\',
      help=\'only check local time\')
 parser.add_argument(\'-s\', \'--set\', action=\'store_true\',
      help=\'only set local time\')
 parser.add_argument(\'-u\', \'--url\', default=url,
      help=\'the url to sync time\')
 args = parser.parse_args()
 if args.set:
  set_beijing_time_from_web(args.url)
 else:
  check_localtime_with_internet(args.url)