Problem Statement

Create a program that downloads the time from this URL:   http://tycho.usno.navy.mil/cgi-bin/timer.pl   and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off this page's talk page.

If possible, only use libraries that come at no extra monetary cost with the programming language and that are widely available and popular such as CPAN for Perl or Boost for C++.

Let's start with the solution:

local http = require("socket.http")    -- Debian package is 'lua-socket'

function scrapeTime (pageAddress, timeZone)
    local page = http.request(pageAddress)
    if not page then return "Cannot connect" end
    for line in page:gmatch("[^<BR>]*") do
        if line:match(timeZone) then
            return line:match("%d+:%d+:%d+")
        end
    end
end

local url = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
print(scrapeTime(url, "UTC"))