How to integrate license file into GUI? (Version 2 - Online Clock)

Hi

I was looking for a way to implement a license into a gui, and I found this: https://se.mathworks.com/matlabcentral/answers/286532-how-to-integrate-license-file-into-gui

However, when I look clearly at the code:

function check_license
  if now > datenum('2017-01-01') % this code stops working Jan 1, 2017
    h = msgbox('Please update your License','License Expired') ;
    quit
  end

Which I have changed to:

function check_license
  if now > datenum('2017-01-01') % this code stops working Jan 1, 2017
    waitfor(msgbox('Please update your License','License Expired')) ;
    quit
  end

But this command "now" gets its time from your computer, so an easy way to cheat the license is just to change the date of your computer before opening the GUI, I need a way for the time to be taken from the internet. Like if there is a command to read: www.timeanddate.com I know servers and computers sync to time.windows.com or time.nist.gov

Answer 1

[Mikkel Ibsen]

If anyone was looking for the same answer I have it here.

function enable = check_license

[~,b]=dos('ping -n 1 www.google.com');
n=strfind(b,'Lost');
n1=b(n+7);
if(n1=='0')
    URL = 'http://tycho.usno.navy.mil/cgi-bin/timer.pl';
atomTime = datenum(regexp(urlread(URL), ...
   '<BR>(.*)\sUTC','tokens','once'),'mmm. dd, HH:MM:SS');
%sysTime = now;
if atomTime > datenum('2017-01-01') % this code stops working Jan 1, 2017
    waitfor(msgbox('Please update your License','License Expired')) ;
    enable = 'off';
else
    enable = 'on';
end
else
    waitfor(msgbox('Please Connect To The Internet','No Internet Connection')) ;
    enable = 'off';
end