Task

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++.




/* web_scraping.wren */
 
import "./pattern" for Pattern
 
var CURLOPT_URL = 10002
var CURLOPT_FOLLOWLOCATION = 52
var CURLOPT_WRITEFUNCTION = 20011
var CURLOPT_WRITEDATA = 10001
 
var BUFSIZE = 16384
 
foreign class Buffer {
    construct new(size) {}
 
    // returns buffer contents as a string
    foreign value
}
 
foreign class Curl {
    construct easyInit() {}
 
    foreign easySetOpt(opt, param)
 
    foreign easyPerform()
 
    foreign easyCleanup()
}
 
var buffer = Buffer.new(BUFSIZE)
var curl = Curl.easyInit()
curl.easySetOpt(CURLOPT_URL, "https://rosettacode.org/wiki/Talk:Web_scraping")
curl.easySetOpt(CURLOPT_FOLLOWLOCATION, 1)
curl.easySetOpt(CURLOPT_WRITEFUNCTION, 0) // write function to be supplied by C
curl.easySetOpt(CURLOPT_WRITEDATA, buffer)
 
curl.easyPerform()
curl.easyCleanup()
 
var html = buffer.value
var ix = html.indexOf("(UTC)")
if (ix == -1) {
    System.print("UTC time not found.")
    return
}
var p = Pattern.new("/d/d:/d/d, #12/d +1/a =4/d")
var m = p.find(html[(ix - 30).max(0)...ix])
System.print(m.text)