#!/bin/bash

ntp_server="clock.redhat.com"
drift_log="./drift.log"

error()
  {
    echo "Error: $1"
    exit 1
  }

[[ `which ntpdate` ]] || error "cannot find ntpdate"

[[ -f /var/lock/subsys/ntpd ]] && /etc/init.d/ntpd stop
[[ -f /var/run/chronyd.pid ]] && /etc/init.d/chrony stop


ntpdate $ntp_server || error "unable to contact NTP server $ntp_server"
/sbin/hwclock

while true
  do
    out=`ntpdate -q $ntp_server | grep ntpdate`
    time=`echo $out | awk '{print $3}'`
    skew=`echo $out | awk '{print $10}' | awk -F. '{print $1}'`
    echo "$time $skew seconds"
    echo "$time $skew seconds" >> $drift_log
    sleep 60
  done