check_time_sync.rb

gistfile1.rb

def check_time_sync 

	require 'net/telnet'

	time_server = 'time.bora.net'

	options = {
	  "Host" => time_server, 
	  "Telnetmode" => false, 
	  "Timeout" => 30, 
	  "Port" => "time"
	}

	# The time is the number of seconds since 00:00 (midnight) 1 January 1900
	# GMT, such that the time 1 is 12:00:01 am on 1 January 1900 GMT; this
	# base will serve until the year 2036.
	seconds = Net::Telnet.new(options).recv(4).unpack('N').first

	# The Ruby Time class handles dates with an epoch 
	# starting at midnight january 1 1970
	# We have to use the Date class to work with pre-epoch dates.
	require 'date'
	def get_seconds_diff_1970_1900
	  # you might want to cache the Cache result... it won't change ;-)
	  (DateTime.new(1970, 1, 1) - DateTime.new(1900, 1, 1)).to_i * 24 * 60 * 60
	end

	# Convert seconds to a Time object
	remote_time = Time.at(seconds - get_seconds_diff_1970_1900).strftime("%Y-%m-%d %H:%M:%S")

	#puts "Time from #{time_server} -> #{remote_time}"

	local_time = Time.now.strftime("%Y-%m-%d %H:%M:%S")

	#puts "Time from local machine -> #{local_time}"


	if (Time.at(seconds - get_seconds_diff_1970_1900).to_i - Time.now.to_i) == 0
		return true		
	else
		return (Time.at(seconds - get_seconds_diff_1970_1900).to_i - Time.now.to_i)
	end

end 

# test

puts check_time_sync()