CODEWITHSUNDEEP
python
Howard Hugh
Howard Hugh

Reputation: 199

ntp client in python

I've written a ntp client in python to query a time server and display the time and the program executes but does not give me any results. I'm using python's 2.7.3 integrated development environment and my OS is Windows 7. Here is the code: 

# File: Ntpclient.py
from socket import AF_INET, SOCK_DGRAM
import sys
import socket
import struct, time

# # Set the socket parameters 

host = "pool.ntp.org"
port = 123
buf = 1024
address = (host,port)
msg = 'time'


# reference time (in seconds since 1900-01-01 00:00:00)
TIME1970 = 2208988800L # 1970-01-01 00:00:00

# connect to server
client = socket.socket( AF_INET, SOCK_DGRAM)
client.sendto(msg, address)
msg, address = client.recvfrom( buf )

t = struct.unpack( "!12I", data )[10]
t -= TIME1970
print "\tTime=%s" % time.ctime(t)

Upvotes: 19

Views: 45249

Answers (4)

Michael
Michael

Reputation: 7756

Here is a fix for the above solution, which adds fractions of seconds to the implementation and closes the socket properly. As it's actually just a handful lines of code, I didn't want to add another dependency to my project, though ntplib admittedly is probably the way to go in most cases.

#!/usr/bin/env python
from contextlib import closing
from socket import socket, AF_INET, SOCK_DGRAM
import struct
import time
   
NTP_PACKET_FORMAT = "!12I"
NTP_DELTA = 2208988800  # 1970-01-01 00:00:00
NTP_QUERY = b'\x1b' + 47 * b'\0'  
    
def ntp_time(host="pool.ntp.org", port=123):
    with closing(socket( AF_INET, SOCK_DGRAM)) as s:
        s.settimeout(5)
        s.sendto(NTP_QUERY, (host, port))
        msg, address = s.recvfrom(1024)
    unpacked = struct.unpack(NTP_PACKET_FORMAT,
                   msg[0:struct.calcsize(NTP_PACKET_FORMAT)])
    return unpacked[10] + float(unpacked[11]) / 2**32 - NTP_DELTA


if __name__ == "__main__":
    print(time.ctime(ntp_time()))

Upvotes: 22

Anuj Gupta
Anuj Gupta

Reputation: 10526

Use ntplib:

The following should work on both Python 2 and 3:

import ntplib
from time import ctime
c = ntplib.NTPClient()
response = c.request('pool.ntp.org')
print(ctime(response.tx_time))

Output:

Fri Jul 28 01:30:53 2017

Upvotes: 28

user3696940
user3696940

Reputation: 39

msg = '\x1b' + 47 * '\0'
.......
t = struct.unpack( "!12I", msg )[10]

Upvotes: 1

Chengy
Chengy

Reputation: 629

It should be 

msg = '\x1b' + 47 * '\0'

Instead of

msg = 'time'

But as Maksym said you should use ntplib instead.

Upvotes: 4

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