Web scraping: Difference between revisions
m →{{header|Wren}}: Minor changes (including code to skip the site notice) and rerun. |
m →{{header|Wren}}: Changed to Wren S/H |
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The code is based in part on the C example though, as we don't have regex, we use our Pattern module to identify the first occurrence of a UTC date/time after the site notice. |
The code is based in part on the C example though, as we don't have regex, we use our Pattern module to identify the first occurrence of a UTC date/time after the site notice. |
||
<syntaxhighlight lang=" |
<syntaxhighlight lang="wren">/* Web_scraping.wren */ |
||
import "./pattern" for Pattern |
import "./pattern" for Pattern |
Latest revision as of 17:00, 16 February 2024
![Task](http://static.miraheze.org/rosettacodewiki/thumb/b/ba/Rcode-button-task-crushed.png/64px-Rcode-button-task-crushed.png)
You are encouraged to solve this task according to the task description, using any language you may know.
- 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++.
8th
\ Web-scrape sample: get UTC time from the US Naval Observatory:
: read-url \ -- s
"http://tycho.usno.navy.mil/cgi-bin/timer.pl" net:get
not if "Could not connect" throw then
>s ;
: get-time
read-url
/<BR>.*?(\d{2}:\d{2}:\d{2})\sUTC/
tuck r:match if
1 r:@ . cr
then ;
get-time bye
- Output:
14:08:20
Ada
with AWS.Client, AWS.Response, AWS.Resources, AWS.Messages;
with Ada.Text_IO, Ada.Strings.Fixed;
use Ada, AWS, AWS.Resources, AWS.Messages;
procedure Get_UTC_Time is
Page : Response.Data;
File : Resources.File_Type;
Buffer : String (1 .. 1024);
Position, Last : Natural := 0;
S : Messages.Status_Code;
begin
Page := Client.Get ("http://tycho.usno.navy.mil/cgi-bin/timer.pl");
S := Response.Status_Code (Page);
if S not in Success then
Text_IO.Put_Line
("Unable to retrieve data => Status Code :" & Image (S) &
" Reason :" & Reason_Phrase (S));
return;
end if;
Response.Message_Body (Page, File);
while not End_Of_File (File) loop
Resources.Get_Line (File, Buffer, Last);
Position :=
Strings.Fixed.Index
(Source => Buffer (Buffer'First .. Last),
Pattern => "UTC");
if Position > 0 then
Text_IO.Put_Line (Buffer (5 .. Position + 2));
return;
end if;
end loop;
end Get_UTC_Time;
ALGOL 68
STRING
domain="tycho.usno.navy.mil",
page="cgi-bin/timer.pl";
STRING # search for the needle in the haystack #
needle = "UTC",
hay stack = "http://"+domain+"/"+page,
re success="^HTTP/[0-9.]* 200",
re result description="^HTTP/[0-9.]* [0-9]+ [a-zA-Z ]*",
re doctype ="\s\s<![Dd][Oo][Cc][Tt][Yy][Pp][Ee] [^>]+>\s+";
PROC raise error = (STRING msg)VOID: ( put(stand error, (msg, new line)); stop);
PROC is html page = (REF STRING page) BOOL: (
BOOL out=grep in string(re success, page, NIL, NIL) = 0;
IF INT start, end;
grep in string(re result description, page, start, end) = 0
THEN
page:=page[end+1:];
IF grep in string(re doctype, page, start, end) = 0
THEN page:=page[start+2:]
ELSE raise error("unknown format retrieving page")
FI
ELSE raise error("unknown error retrieving page")
FI;
out
);
STRING reply;
INT rc = http content (reply, domain, haystack, 0);
IF rc = 0 AND is html page (reply)
THEN
STRING line; FILE freply; associate(freply, reply);
on logical file end(freply, (REF FILE freply)BOOL: (done; SKIP));
DO
get(freply,(line, new line));
IF string in string(needle, NIL, line) THEN print((line, new line)) FI
OD;
done: SKIP
ELSE raise error (strerror (rc))
FI
- Output:
Sample
<BR>Sep. 26, 21:51:17 UTC Universal Time
App Inventor
App Inventor has a Web component that contains code blocks which simplify Web scraping.
It also has powerful text and list processing language blocks that simplify text scraping.
This is how the code would look if it could be typed:
when ScrapeButton.Click do
set ScrapeWeb.Url to SourceTextBox.Text
call ScrapeWeb.Get
when ScrapeWeb.GotText url,responseCode,responseType,responseContent do
initialize local Left to split at first text (text: get responseContent, at: PreTextBox.Text)
initialize local Right to "" in
set Right to select list item (list: get Left, index: 2)
set ResultLabel.Text to select list item (list: split at first (text:get Right, at: PostTextBox.Text), index: 1)
A picture of the graphical program/
AppleScript
"Alternatively, if the above url is not working, grab the first date/time off this page's talk page." At the time of posting, the first date/time on the talk page is in Michael Mol's invitation to RC's Slack. The code here's aimed specifically at the first date on a page (but can be modified) and doesn't include error handling.
use AppleScript version "2.4" -- OS X 10.10 (Yosemite) or later
use framework "Foundation"
on firstDateonWebPage(URLText)
set |⌘| to current application
set pageURL to |⌘|'s class "NSURL"'s URLWithString:(URLText)
-- Fetch the page HTML as data.
-- The Xcode documentation advises against using dataWithContentsOfURL: over a network,
-- but I'm guessing this applies to downloading large files rather than a Web page's HTML.
-- If in doubt, the HTML can be fetched as text instead and converted to data in house.
set HTMLData to |⌘|'s class "NSData"'s dataWithContentsOfURL:(pageURL)
-- Or:
(*
set {HTMLText, encoding} to |⌘|'s class "NSString"'s stringWithContentsOfURL:(pageURL) ¬
usedEncoding:(reference) |error|:(missing value)
set HTMLData to HTMLText's dataUsingEncoding:(encoding)
*)
-- Extract the page's visible text from the HTML.
set straightText to (|⌘|'s class "NSAttributedString"'s alloc()'s initWithHTML:(HTMLData) ¬
documentAttributes:(missing value))'s |string|()
-- Use an NSDataDetector to locate the first date in the text. (It's assumed here there'll be one.)
set dateDetector to |⌘|'s class "NSDataDetector"'s dataDetectorWithTypes:(|⌘|'s NSTextCheckingTypeDate) ¬
|error|:(missing value)
set matchRange to dateDetector's rangeOfFirstMatchInString:(straightText) options:(0) ¬
range:({0, straightText's |length|()})
-- Return the date text found.
return (straightText's substringWithRange:(matchRange)) as text
end firstDateonWebPage
firstDateonWebPage("https://www.rosettacode.org/wiki/Talk:Web_scraping")
- Output:
"20:59, 30 May 2020"
AutoHotkey
UrlDownloadToFile, http://tycho.usno.navy.mil/cgi-bin/timer.pl, time.html
FileRead, timefile, time.html
pos := InStr(timefile, "UTC")
msgbox % time := SubStr(timefile, pos - 9, 8)
AWK
This is inspired by GETURL example in the manual for gawk.
#! /usr/bin/awk -f
BEGIN {
purl = "/inet/tcp/0/tycho.usno.navy.mil/80"
ORS = RS = "\r\n\r\n"
print "GET /cgi-bin/timer.pl HTTP/1.0" |& purl
purl |& getline header
while ( (purl |& getline ) > 0 )
{
split($0, a, "\n")
for(i=1; i <= length(a); i++)
{
if ( a[i] ~ /UTC/ )
{
sub(/^<BR>/, "", a[i])
printf "%s\n", a[i]
}
}
}
close(purl)
}
BBC BASIC
Note that the URL cache is cleared so the code works correctly if run more than once.
SYS "LoadLibrary", "URLMON.DLL" TO urlmon%
SYS "GetProcAddress", urlmon%, "URLDownloadToFileA" TO UDTF%
SYS "LoadLibrary", "WININET.DLL" TO wininet%
SYS "GetProcAddress", wininet%, "DeleteUrlCacheEntryA" TO DUCE%
url$ = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
file$ = @tmp$+"navytime.txt"
SYS DUCE%, url$
SYS UDTF%, 0, url$, file$, 0, 0 TO result%
IF result% ERROR 100, "Download failed"
file% = OPENIN(file$)
REPEAT
text$ = GET$#file%
IF INSTR(text$, "UTC") PRINT MID$(text$, 5)
UNTIL EOF#file%
CLOSE #file%
C
There is no proper error handling.
#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
#include <sys/types.h>
#include <regex.h>
#define BUFSIZE 16384
size_t lr = 0;
size_t filterit(void *ptr, size_t size, size_t nmemb, void *stream)
{
if ( (lr + size*nmemb) > BUFSIZE ) return BUFSIZE;
memcpy(stream+lr, ptr, size*nmemb);
lr += size*nmemb;
return size*nmemb;
}
int main()
{
CURL *curlHandle;
char buffer[BUFSIZE];
regmatch_t amatch;
regex_t cregex;
curlHandle = curl_easy_init();
curl_easy_setopt(curlHandle, CURLOPT_URL, "http://tycho.usno.navy.mil/cgi-bin/timer.pl");
curl_easy_setopt(curlHandle, CURLOPT_FOLLOWLOCATION, 1);
curl_easy_setopt(curlHandle, CURLOPT_WRITEFUNCTION, filterit);
curl_easy_setopt(curlHandle, CURLOPT_WRITEDATA, buffer);
int success = curl_easy_perform(curlHandle);
curl_easy_cleanup(curlHandle);
buffer[lr] = 0;
regcomp(&cregex, " UTC", REG_NEWLINE);
regexec(&cregex, buffer, 1, &amatch, 0);
int bi = amatch.rm_so;
while ( bi-- > 0 )
if ( memcmp(&buffer[bi], "<BR>", 4) == 0 ) break;
buffer[amatch.rm_eo] = 0;
printf("%s\n", &buffer[bi+4]);
regfree(&cregex);
return 0;
}
C#
class Program
{
static void Main(string[] args)
{
WebClient wc = new WebClient();
Stream myStream = wc.OpenRead("http://tycho.usno.navy.mil/cgi-bin/timer.pl");
string html = "";
using (StreamReader sr = new StreamReader(myStream))
{
while (sr.Peek() >= 0)
{
html = sr.ReadLine();
if (html.Contains("UTC"))
{
break;
}
}
}
Console.WriteLine(html.Remove(0, 4));
Console.ReadLine();
}
}
C++
#include <iostream>
#include <string>
#include <boost/asio.hpp>
#include <boost/regex.hpp>
int main()
{
boost::asio::ip::tcp::iostream s("tycho.usno.navy.mil", "http");
if(!s)
std::cout << "Could not connect to tycho.usno.navy.mil\n";
s << "GET /cgi-bin/timer.pl HTTP/1.0\r\n"
<< "Host: tycho.usno.navy.mil\r\n"
<< "Accept: */*\r\n"
<< "Connection: close\r\n\r\n" ;
for(std::string line; getline(s, line); )
{
boost::smatch matches;
if(regex_search(line, matches, boost::regex("<BR>(.+\\s+UTC)") ) )
{
std::cout << matches[1] << '\n';
break;
}
}
}
Caché ObjectScript
Class Utils.Net [ Abstract ]
{
ClassMethod ExtractHTMLData(pHost As %String = "", pPath As %String = "", pRegEx As %String = "", Output list As %List) As %Status
{
// implement error handling
Try {
// some initialisation
Set list="", sc=$$$OK
// check input parameters
If $Match(pHost, "^([a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$")=0 {
Set sc=$$$ERROR($$$GeneralError, "Invalid host name.")
Quit
}
// create http request and get page
Set req=##class(%Net.HttpRequest).%New()
Set req.Server=pHost
Do req.Get(pPath)
// check for success
If $Extract(req.HttpResponse.StatusCode)'=2 {
Set sc=$$$ERROR($$$GeneralError, "Page not loaded.")
Quit
}
// read http response stream
Set html=req.HttpResponse.Data
Set html.LineTerminator=$Char(10)
Set sc=html.Rewind()
// read http response stream
While 'html.AtEnd {
Set line=html.ReadLine(, .sc, .eol)
Set pos=$Locate(line, pRegEx)
If pos {
Set parse=$Piece($Extract(line, pos, *), $Char(9))
Set slot=$ListLength(list)+1
Set $List(list, slot)=parse
}
}
} Catch err {
// an error has occurred
If err.Name="<REGULAR EXPRESSION>" {
Set sc=$$$ERROR($$$GeneralError, "Invalid regular expression.")
} Else {
Set sc=$$$ERROR($$$CacheError, $ZError)
}
}
// return status
Quit sc
}
}
- Examples:
USER>Do ##class(Utils.Net).ExtractHTMLData("tycho.usno.navy.mil", "/cgi-bin/timer.pl", "[A-Za-z\.]{3,5} \d{1,2}, \d{1,2}:\d{2}:\d{2} UTC", .list) USER>Write $List(list) Mar. 29, 20:45:27 UTC USER>Do ##class(Utils.Net).ExtractHTMLData("tycho.usno.navy.mil", "/cgi-bin/timer.pl", "[A-Za-z\.]{3,5} \d{1,2}, \d{1,2}:\d{2}:\d{2}", .list) USER>Write $ListToString(list, $Char(13,10)) Mar. 29, 20:47:42 UTC Mar. 29, 04:47:42 PM EDT Mar. 29, 03:47:42 PM CDT Mar. 29, 02:47:42 PM MDT Mar. 29, 01:47:42 PM PDT Mar. 29, 12:47:42 PM AKDT Mar. 29, 10:47:42 AM HAST
Ceylon
Don't forget to import ceylon.uri and ceylon.http.client in your module.ceylon file.
import ceylon.uri {
parse
}
import ceylon.http.client {
get
}
shared void run() {
// apparently the cgi link is deprecated?
value oldUri = "http://tycho.usno.navy.mil/cgi-bin/timer.pl";
value newUri = "http://tycho.usno.navy.mil/timer.pl";
value contents = downloadContents(newUri);
value time = extractTime(contents);
print(time else "nothing found");
}
String downloadContents(String uriString) {
value uri = parse(uriString);
value request = get(uri);
value response = request.execute();
return response.contents;
}
String? extractTime(String contents) =>
contents
.lines
.filter((String element) => element.contains("UTC"))
.first
?.substring(4, 21);
Clojure
Clojure 1.2:
(second (re-find #" (\d{1,2}:\d{1,2}:\d{1,2}) UTC" (slurp "http://tycho.usno.navy.mil/cgi-bin/timer.pl")))
CoffeeScript
http = require 'http'
CONFIG =
host: 'tycho.usno.navy.mil'
path: '/cgi-bin/timer.pl'
# Web scraping code tends to be brittle, and this is no exception.
# The tycho time page does not use highly structured markup, so
# we do a real dirty scrape.
scrape_tycho_ust_time = (text) ->
for line in text.split '\n'
matches = line.match /(.*:\d\d UTC)/
if matches
console.log matches[0].replace '<BR>', ''
return
throw Error("unscrapable page!")
# This is low-level-ish code to get data from a URL. It's
# pretty general purpose, so you'd normally tuck this away
# in a library (or use somebody else's library).
wget = (host, path, cb) ->
options =
host: host
path: path
headers:
"Cache-Control": "max-age=0"
req = http.request options, (res) ->
s = ''
res.on 'data', (chunk) ->
s += chunk
res.on 'end', ->
cb s
req.end()
# Do our web scrape
do ->
wget CONFIG.host, CONFIG.path, (data) ->
scrape_tycho_ust_time data
- Output:
> coffee web_scrape.coffee Jan. 09, 19:19:07 UTC
Common Lisp
BOA> (let* ((url "http://tycho.usno.navy.mil/cgi-bin/timer.pl")
(regexp (load-time-value
(cl-ppcre:create-scanner "(?m)^.{4}(.+? UTC)")))
(data (drakma:http-request url)))
(multiple-value-bind (start end start-regs end-regs)
(cl-ppcre:scan regexp data)
(declare (ignore end))
(when start
(subseq data (aref start-regs 0) (aref end-regs 0)))))
"Aug. 12, 04:29:51 UTC"
Another Common Lisp solution
CL-USER> (cl-ppcre:do-matches-as-strings
(m ".*<BR>(.*)UTC.*"
(drakma:http-request "http://tycho.usno.navy.mil/cgi-bin/timer.pl"))
(print (cl-ppcre:regex-replace "<BR>(.*UTC).*" m "\\1")))
"Jul. 13, 06:32:01 UTC"
D
void main() {
import std.stdio, std.string, std.net.curl, std.algorithm;
foreach (line; "http://tycho.usno.navy.mil/cgi-bin/timer.pl".byLine)
if (line.canFind(" UTC"))
line[4 .. $].writeln;
}
Delphi
There are a number of ways to do this with Delphi using any one of a number of free/open source TCP/IP component suites such as, for example, ICS, Synapse and Indy (which ships with Delphi anyway). However, I thought it would be interesting to do this using the Winsock API direct.
program WebScrape;
{$APPTYPE CONSOLE}
{.$DEFINE DEBUG}
uses
Classes,
Winsock;
{ Function to connect to host, send HTTP request and retrieve response }
function DoHTTPGET(const hostName: PAnsiChar; const resource: PAnsiChar; HTTPResponse: TStrings): Boolean;
const
Port: integer = 80;
CRLF = #13#10; // carriage return/line feed
var
WSAData: TWSAData;
Sock: TSocket;
SockAddrIn: TSockAddrIn;
IPAddress: PHostEnt;
bytesIn: integer;
inBuffer: array [0..1023] of char;
Req: string;
begin
Result := False;
HTTPResponse.Clear;
{ Initialise use of the Windows Sockets DLL.
Older Windows versions support Winsock 1.1 whilst newer Windows
include Winsock 2 but support 1.1. Therefore, we'll specify
version 1.1 ($101) as being the highest version of Windows Sockets
that we can use to provide greatest flexibility.
WSAData receives details of the Windows Sockets implementation }
Winsock.WSAStartUp($101, WSAData);
try
{ Create a socket for TCP/IP usage passing in
Address family spec: AF_INET (TCP, UDP, etc.)
Type specification: SOCK_STREAM
Protocol: IPPROTO_TCP (TCP) }
Sock := WinSock.Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
try
// Check we have a valid socket
if (Sock <> INVALID_SOCKET) then
begin
// Populate socket address structure
with SockAddrIn do
begin
// Address family specification
sin_family := AF_INET;
// Port
sin_port := htons(Port);
// Address
sin_addr.s_addr := inet_addr(hostName);
end;
if (SockAddrIn.sin_addr.s_addr = INADDR_NONE) then
begin
{ As we're using a domain name instead of an
IP Address, we need to resolve the domain name }
IPAddress := Winsock.gethostbyname(hostName);
// Quit if we didn't get an IP Address
if (IPAddress = nil) then
Exit;
// Update the structure with the IP Address
SockAddrIn.sin_addr.s_addr := PLongint(IPAddress^.h_addr_list^)^;
end;
// Try to connect to host
if (Winsock.connect(Sock, SockAddrIn, SizeOf(SockAddrIn)) <> SOCKET_ERROR) then
begin
// OK - Connected
// Compose our request
// Each line of the request must be terminated with a carriage return/line feed
{ The First line specifies method (e.g. GET, POST), path to required resource,
and the HTTP version being used. These three fields are space separated. }
Req := 'GET '+resource+' HTTP/1.1' + CRLF +
// Host: is the only Required header in HTTP 1.1
'Host: '+hostName + CRLF +
{ Persistent connections are the default in HTTP 1.1 but, as we don't want
or need one for this exercise, we must include the "Connection: close"
header in our request }
'Connection: close' + CRLF +
CRLF; // Request must end with an empty line!
// Try to send the request to the host
if (Winsock.send(Sock,Req[1],Length(Req),0) <> SOCKET_ERROR) then
begin
// Initialise incoming data buffer (i.e. fill array with nulls)
FillChar(inBuffer,SizeOf(inBuffer),#0);
// Loop until nothing left to read
repeat
// Read incoming data from socket
bytesIn := Winsock.recv(Sock, inBuffer, SizeOf(inBuffer), 0);
// Assign buffer to Stringlist
HTTPResponse.Text := HTTPResponse.Text + Copy(string(inBuffer),1,bytesIn);
until
(bytesIn <= 0) or (bytesIn = SOCKET_ERROR);
{ Our list of response strings should
contain at least 1 line }
Result := HTTPResponse.Count > 0;
end;
end;
end;
finally
// Close our socket
Winsock.closesocket(Sock);
end;
finally
{ This causes our application to deregister itself from this
Windows Sockets implementation and allows the implementation
to free any resources allocated on our behalf. }
Winsock.WSACleanup;
end;
end;
{ Simple function to locate and return the UTC time from the
request sent to http://tycho.usno.navy.mil/cgi-bin/timer.pl
The HTTPResponse parameter contains both the HTTP Headers and
the HTML served up by the requested resource. }
function ParseResponse(HTTPResponse: TStrings): string;
var
i: Integer;
begin
Result := '';
{ Check first line for server response code
We want something like this: HTTP/1.1 200 OK }
if Pos('200',HTTPResponse[0]) > 0 then
begin
for i := 0 to Pred(HTTPResponse.Count) do
begin
{ The line we're looking for is something like this:
<BR>May. 04. 21:55:19 UTC Universal Time }
// Check each line
if Pos('UTC',HTTPResponse[i]) > 0 then
begin
Result := Copy(HTTPResponse[i],5,Pos('UTC',HTTPResponse[i])-1);
Break;
end;
end;
end
else
Result := 'HTTP Error: '+HTTPResponse[0];
end;
const
host: PAnsiChar = 'tycho.usno.navy.mil';
res : PAnsiChar = '/cgi-bin/timer.pl';
var
Response: TStrings;
begin
{ A TStringList is a TStrings descendant class
that is used to store and manipulate a list
of strings.
Instantiate a stringlist class to
hold the results of our HTTP GET }
Response := TStringList.Create;
try
// Try an HTTP GET request
if DoHTTPGET(host,res,Response) then
begin
{$IFDEF DEBUG}
{ Write the entire response to
the console window }
Writeln(Response.text);
{$ELSE}
{ Parse the response and write the
result to the console window }
Writeln(ParseResponse(Response));
{$ENDIF DEBUG}
end
else
Writeln('Error retrieving data');
finally
Response.Free;
end;
// Keep console window open
Readln;
end.
Example using Indy's IdHTTP component.
program ReadUTCTime;
{$APPTYPE CONSOLE}
uses SysUtils, Classes, IdHTTP;
var
s: string;
lHTTP: TIdHTTP;
lReader: TStringReader;
begin
lHTTP := TIdHTTP.Create(nil);
try
lReader := TStringReader.Create(lHTTP.Get('http://tycho.usno.navy.mil/cgi-bin/timer.pl'));
while lReader.Peek > 0 do
begin
s := lReader.ReadLine;
if Pos('UTC', s) > 0 then
begin
Writeln(s);
Break;
end;
end;
finally
lHTTP.Free;
lReader.Free;
end;
end.
E
interp.waitAtTop(when (def html := <http://tycho.usno.navy.mil/cgi-bin/timer.pl>.getText()) -> {
def rx`(?s).*>(@time.*? UTC).*` := html
println(time)
})
Erlang
Using regular expressions:
-module(scraping).
-export([main/0]).
-define(Url, "http://tycho.usno.navy.mil/cgi-bin/timer.pl").
-define(Match, "<BR>(.+ UTC)").
main() ->
inets:start(),
{ok, {_Status, _Header, HTML}} = httpc:request(?Url),
{match, [Time]} = re:run(HTML, ?Match, [{capture, all_but_first, binary}]),
io:format("~s~n",[Time]).
F#
This code is asynchronous - it will not block any threads while it waits on a response from the remote server.
open System
open System.Net
open System.Text.RegularExpressions
async {
use wc = new WebClient()
let! html = wc.AsyncDownloadString(Uri("http://tycho.usno.navy.mil/cgi-bin/timer.pl"))
return Regex.Match(html, @"<BR>(.+ UTC)").Groups.[1].Value
}
|> Async.RunSynchronously
|> printfn "%s"
Factor
USING: http.client io sequences ;
"http://tycho.usno.navy.mil/cgi-bin/timer.pl" http-get nip
[ "UTC" swap start [ 9 - ] [ 1 - ] bi ] keep subseq print
Forth
include unix/socket.fs
: extract-time ( addr len type len -- time len )
dup >r
search 0= abort" that time not present!"
dup >r
begin -1 /string over 1- c@ [char] > = until \ seek back to <BR> at start of line
r> - r> + ;
s" tycho.usno.navy.mil" 80 open-socket
dup s\" GET /cgi-bin/timer.pl HTTP/1.0\n\n" rot write-socket
dup pad 4096 read-socket
s\" \r\n\r\n" search 0= abort" can't find headers!" \ skip headers
s" UTC" extract-time type cr
close-socket
FunL
import io.Source
case Source.fromURL( 'http://tycho.usno.navy.mil/cgi-bin/timer.pl', 'UTF-8' ).getLines().find( ('Eastern' in) ) of
Some( time ) -> println( time.substring(4) )
None -> error( 'Easter time not found' )
- Output:
Jul. 24, 01:38:23 AM EDT Eastern Time
Gambas
Public Sub Main()
Dim sWeb, sTemp, sOutput As String 'Variables
Shell "wget -O /tmp/web http://tycho.usno.navy.mil/cgi-bin/timer.pl" Wait 'Use 'wget' to save the web file in /tmp/
sWeb = File.Load("/tmp/web") 'Open file and store in sWeb
For Each sTemp In Split(sWeb, gb.NewLine) 'Split the file by NewLines..
If InStr(sTemp, "UTC") Then 'If the line contains "UTC" then..
sOutPut = sTemp 'Extract the line into sOutput
Break 'Get out of here
End If
Next
Print Mid(sOutput, 5) 'Print the result without the '<BR>' tag
End
Output:
Jun. 10, 15:22:25 UTC Universal Time
Go
package main
import (
"bytes"
"encoding/xml"
"fmt"
"io"
"net/http"
"regexp"
"time"
)
func main() {
resp, err := http.Get("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
if err != nil {
fmt.Println(err) // connection or request fail
return
}
defer resp.Body.Close()
var us string
var ux int
utc := []byte("UTC")
for p := xml.NewDecoder(resp.Body); ; {
t, err := p.RawToken()
switch err {
case nil:
case io.EOF:
fmt.Println("UTC not found")
return
default:
fmt.Println(err) // read or parse fail
return
}
if ub, ok := t.(xml.CharData); ok {
if ux = bytes.Index(ub, utc); ux != -1 {
// success: found a line with the string "UTC"
us = string([]byte(ub))
break
}
}
}
// first thing to try: parsing the expected date format
if t, err := time.Parse("Jan. 2, 15:04:05 UTC", us[:ux+3]); err == nil {
fmt.Println("parsed UTC:", t.Format("January 2, 15:04:05"))
return
}
// fallback: search for anything looking like a time and print that
tx := regexp.MustCompile("[0-2]?[0-9]:[0-5][0-9]:[0-6][0-9]")
if justTime := tx.FindString(us); justTime > "" {
fmt.Println("found UTC:", justTime)
return
}
// last resort: just print the whole element containing "UTC" and hope
// there is a human readable time in there somewhere.
fmt.Println(us)
}
- Output:
parsed UTC: May 23, 00:44:13
Groovy
def time = "unknown"
def text = new URL('http://tycho.usno.navy.mil/cgi-bin/timer.pl').eachLine { line ->
def matcher = (line =~ "<BR>(.+) UTC")
if (matcher.find()) {
time = matcher[0][1]
}
}
println "UTC Time was '$time'"
- Output:
UTC Time was 'Feb. 26, 11:02:30'
Haskell
Using package HTTP-4000.0.8 from HackgageDB
import Data.List
import Network.HTTP (simpleHTTP, getResponseBody, getRequest)
tyd = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
readUTC = simpleHTTP (getRequest tyd)>>=
fmap ((!!2).head.dropWhile ("UTC"`notElem`).map words.lines). getResponseBody>>=putStrLn
Usage in GHCi:
*Main> readUTC
08:30:23
Icon and Unicon
Icon
Icon has capability to read web pages using the external function cfunc. The Unicon messaging extensions are more succinct.
Unicon
procedure main()
m := open(url := "http://tycho.usno.navy.mil/cgi-bin/timer.pl","m") | stop("Unable to open ",url)
every (p := "") ||:= |read(m) # read the page into a single string
close(m)
map(p) ? ( tab(find("<br>")), ="<br>", write("UTC time=",p[&pos:find(" utc")])) # scrape and show
end
J
require 'web/gethttp'
_8{. ' UTC' taketo gethttp 'http://tycho.usno.navy.mil/cgi-bin/timer.pl'
04:32:44
The web/gethttp
addon uses Wget on Linux or Windows (J ships with Wget on Windows) and cURL on the Mac.
(A sockets solution is also possible. But, while basic HTTP support is trivial to implement, a full standards compliant implementation and can involve a lot of code to deal with rare corner cases, and the time required to complete a web request is often significantly longer than the time to invoke an external program. This would imply a fair bit of maintenance and testing overhead to deal with issues which rarely matter, if a direct sockets implementation were used.)
Java
The http://tycho.usno.navy.mil/cgi-bin/timer.pl address is no longer available, although the parsing of the text is incredibly simple.
String scrapeUTC() throws URISyntaxException, IOException {
String address = "http://tycho.usno.navy.mil/cgi-bin/timer.pl";
URL url = new URI(address).toURL();
try (BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()))) {
Pattern pattern = Pattern.compile("^.+? UTC");
Matcher matcher;
String line;
while ((line = reader.readLine()) != null) {
matcher = pattern.matcher(line);
if (matcher.find())
return matcher.group().replaceAll("<.+?>", "");
}
}
return null;
}
I'm using a cached page and get the following output.
Jun. 25, 17:59:15 UTC
Alternately, using Java 8, with the new web address given in the task description.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
public final class WebScraping {
public static void main(String[] aArgs) {
try {
URI uri = new URI("https://www.rosettacode.org/wiki/Talk:Web_scraping").parseServerAuthority();
URL address = uri.toURL();
HttpURLConnection connection = (HttpURLConnection) address.openConnection();
BufferedReader reader = new BufferedReader( new InputStreamReader(connection.getInputStream()) );
final int responseCode = connection.getResponseCode();
System.out.println("Response code: " + responseCode);
String line;
while ( ! ( line = reader.readLine() ).contains("UTC") ) {
/* Empty block */
}
final int index = line.indexOf("UTC");
System.out.println(line.substring(index - 16, index + 4));
reader.close();
connection.disconnect();
} catch (IOException ioe) {
System.err.println("Error connecting to server: " + ioe.getCause());
} catch (URISyntaxException use) {
System.err.println("Unable to connect to URI: " + use.getCause());
}
}
}
- Output:
Response code: 200 25 August 2022 (UTC)
JavaScript
Due to browser cross-origin restrictions, this script will probably not work in other domains.
var req = new XMLHttpRequest();
req.onload = function () {
var re = /[JFMASOND].+ UTC/; //beginning of month name to 'UTC'
console.log(this.responseText.match(re)[0]);
};
req.open('GET', 'http://tycho.usno.navy.mil/cgi-bin/timer.pl', true);
req.send();
jq
Currently jq does not have built-in curl support, but jq is intended to work seamlessly with other command-line utilities, so we present a simple solution to the problem in the form of a three-line script:
#!/bin/bash
curl -Ss 'http://tycho.usno.navy.mil/cgi-bin/timer.pl' |\
jq -R -r 'if index(" UTC") then .[4:] else empty end'
- Output:
$ ./Web_scraping.jq
Apr. 21, 05:19:32 UTC Universal Time
Julia
I'm using the Requests.jl
package for this solution. Note, I used a slightly different URL after finding that the one specified in the task description is deprecated (though it still works).
using Requests, Printf
function getusnotime()
const url = "http://tycho.usno.navy.mil/timer.pl"
s = try
get(url)
catch err
@sprintf "get(%s)\n => %s" url err
end
isa(s, Requests.Response) || return (s, false)
t = match(r"(?<=<BR>)(.*?UTC)", readstring(s))
isa(t, RegexMatch) || return (@sprintf("raw html:\n %s", readstring(s)), false)
return (t.match, true)
end
(t, issuccess) = getusnotime();
if issuccess
println("The USNO time is ", t)
else
println("Failed to fetch UNSO time:\n", t)
end
- Output:
The USNO time is Apr. 20, 17:54:54 UTC
Checks of Failure Detection
By breaking the USNO URL
Failed to fetch UNSO time: get(http://sycho.usno.navy.mil/timer.pl) => getaddrinfo callback: unknown node or service (EAI_NONAME)
By breaking the regular expression (using <BR>(.*UTd)
)
Failed to fetch UNSO time:
raw html:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final"//EN>
<html>
<body>
<TITLE>What time is it?</TITLE>
<H2> US Naval Observatory Master Clock Time</H2> <H3><PRE>
<BR>Apr. 20, 17:55:31 UTC Universal Time
<BR>Apr. 20, 01:55:31 PM EDT Eastern Time
<BR>Apr. 20, 12:55:31 PM CDT Central Time
<BR>Apr. 20, 11:55:31 AM MDT Mountain Time
<BR>Apr. 20, 10:55:31 AM PDT Pacific Time
<BR>Apr. 20, 09:55:31 AM AKDT Alaska Time
<BR>Apr. 20, 07:55:31 AM HAST Hawaii-Aleutian Time
</PRE></H3><P><A HREF="http://www.usno.navy.mil"> US Naval Observatory</A>
</body></html>
Kotlin
// version 1.1.3
import java.net.URL
import java.io.InputStreamReader
import java.util.Scanner
fun main(args: Array<String>) {
val url = URL("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
val isr = InputStreamReader(url.openStream())
val sc = Scanner(isr)
while (sc.hasNextLine()) {
val line = sc.nextLine()
if ("UTC" in line) {
println(line.drop(4).take(17))
break
}
}
sc.close()
}
Sample output:
Aug. 20, 22:38:26
Lasso
/* have to be used
local(raw_htmlstring = '<TITLE>What time is it?</TITLE>
<H2> US Naval Observatory Master Clock Time</H2> <H3><PRE>
<BR>Jul. 27, 22:57:22 UTC Universal Time
<BR>Jul. 27, 06:57:22 PM EDT Eastern Time
<BR>Jul. 27, 05:57:22 PM CDT Central Time
<BR>Jul. 27, 04:57:22 PM MDT Mountain Time
<BR>Jul. 27, 03:57:22 PM PDT Pacific Time
<BR>Jul. 27, 02:57:22 PM AKDT Alaska Time
<BR>Jul. 27, 12:57:22 PM HAST Hawaii-Aleutian Time
</PRE></H3>
')
*/
// should be used
local(raw_htmlstring = string(include_url('http://tycho.usno.navy.mil/cgi-bin/timer.pl')))
local(
reg_exp = regexp(-find = `<br>(.*?) UTC`, -input = #raw_htmlstring, -ignorecase),
datepart_txt = #reg_exp -> find ? #reg_exp -> matchstring(1) | string
)
#datepart_txt
'<br />'
// added bonus showing how parsed string can be converted to date object
local(mydate = date(#datepart_txt, -format = `MMM'.' dd',' HH:mm:ss`))
#mydate -> format(`YYYY-MM-dd HH:mm:ss`)
Result: Jul. 27, 22:57:22
2013-07-27 22:57:22
Liberty BASIC
if DownloadToFile("http://tycho.usno.navy.mil/cgi-bin/timer.pl", DefaultDir$ + "\timer.htm") = 0 then
open DefaultDir$ + "\timer.htm" for input as #f
html$ = lower$(input$(#f, LOF(#f)))
close #f
a= instr( html$, "utc" )-1
print "UTC";mid$( html$, a-9,9)
end if
end
function DownloadToFile(urlfile$, localfile$)
open "URLmon" for dll as #url
calldll #url, "URLDownloadToFileA",_
0 as long,_ 'null
urlfile$ as ptr,_ 'url to download
localfile$ as ptr,_ 'save file name
0 as long,_ 'reserved, must be 0
0 as long,_ 'callback address, can be 0
DownloadToFile as ulong '0=success
close #url
end function
Because Liberty has to do web operations in ways like this, calling Windows DLLs, there is the Run BASIC variant of LB, in which the task becomes a one-liner.
Lua
The web page is split on the HTML line break tags. Each line is checked for the required time zone code. Once it is found, we return the instance within that line of three numbers separated by colons - I.E. the time.
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"))
The task description states "just the UTC time" but of course we could return the whole line including the zone name and date if required.
M2000 Interpreter
Module Web_scraping {
Print "Web scraping"
function GetTime$(a$, what$="UTC") {
document a$ ' change string to document
find a$, what$ ' place data to stack
Read find_pos
if find_pos>0 then
read par_order, par_pos
b$=paragraph$(a$, par_order)
k=instr(b$,">")
if k>0 then if k<par_pos then b$=mid$(b$,k+1) :par_pos-=k
k=rinstr(b$,"<")
if k>0 then if k>par_pos then b$=Left(b$,k-1)
=b$
end if
}
declare msxml2 "MSXML2.XMLHTTP.6.0"
rem print type$(msxml2)="IXMLHTTPRequest"
Url$ = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
try ok {
method msxml2, "Open", "GET", url$, false
method msxml2,"Send"
with msxml2,"responseText" as txt$
Print GetTime$(txt$)
}
If error or not ok then Print Error$
declare msxml2 nothing
}
Web_scraping
Maple
text := URL:-Get("http://tycho.usno.navy.mil/cgi-bin/timer.pl"):
printf(StringTools:-StringSplit(text,"<BR>")[2]);
- Output:
May. 16, 20:17:28 UTC Universal Time
Mathematica /Wolfram Language
test = StringSplit[Import["http://tycho.usno.navy.mil/cgi-bin/timer.pl"], "\n"];
Extract[test, Flatten@Position[StringFreeQ[test, "UTC"], False]]
MATLAB / Octave
s = urlread('http://tycho.usno.navy.mil/cgi-bin/timer.pl');
ix = [findstr(s,'<BR>'), length(s)+1];
for k = 2:length(ix)
tok = s(ix(k-1)+4:ix(k)-1);
if findstr(tok,'UTC')
disp(tok);
end;
end;
Microsoft Small Basic
'Entered by AykayayCiti -- Earl L. Montgomery
url_name = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
url_data = Network.GetWebPageContents(url_name)
find = "UTC"
' the length from the UTC to the time is -18 so we need
' to subtract from the UTC position
pos = Text.GetIndexOf(url_data,find)-18
result = Text.GetSubText(url_data,pos,(18+3)) 'plus 3 to add the UTC
TextWindow.WriteLine(result)
'you can eleminate a line of code by putting the
' GetIndexOf insde the GetSubText
'result2 = Text.GetSubText(url_data,Text.GetIndexOf(url_data,find)-18,(18+3))
'TextWindow.WriteLine(result2)
- Output:
Mar. 19, 04:19:34 UTC Press any key to continue...
mIRC Scripting Language
alias utc {
sockclose UTC
sockopen UTC tycho.usno.navy.mil 80
}
on *:SOCKOPEN:UTC: {
sockwrite -n UTC GET /cgi-bin/timer.pl HTTP/1.1
sockwrite -n UTC Host: tycho.usno.navy.mil
sockwrite UTC $crlf
}
on *:SOCKREAD:UTC: {
sockread %UTC
while ($sockbr) {
if (<BR>*Universal Time iswm %UTC) {
echo -ag $remove(%UTC,<BR>,$chr(9),Universal Time)
unset %UTC
sockclose UTC
return
}
sockread %UTC
}
}
NetRexx
/* NetRexx */
options replace format comments java crossref symbols binary
parse arg full_short .
if 'FULL'.abbrev(full_short.upper(), 1) then
dateFull = isTrue()
else
dateFull = isFalse()
do
timeURL = java.net.URL('http://tycho.usno.navy.mil/cgi-bin/timer.pl')
conn = timeURL.openConnection()
ibr = BufferedReader(InputStreamReader(conn.getInputStream()))
line = Rexx
loop label readLoop while ibr.ready()
line = ibr.readLine()
if line = null then leave readLoop
line = line.translate(' ', '\t')
if line.wordpos('UTC') > 0 then do
parse line . '>' udatetime 'UTC' . -
0 . '>' . ',' utime 'UTC' .
if dateFull then
say udatetime.strip() 'UTC'
else
say utime.strip()
leave readLoop
end
end readLoop
ibr.close()
catch ex = IOException
ex.printStackTrace()
end
method isTrue() public constant returns boolean
return 1 == 1
method isFalse() public constant returns boolean
return \isTrue()
- Output:
04:29:09
or with an argument that matches 'FULL':
Jul. 18, 04:29:09 UTC
Nim
Using Rosetta Talk page URL.
import httpclient, strutils
var client = newHttpClient()
var res: string
for line in client.getContent("https://rosettacode.org/wiki/Talk:Web_scraping").splitLines:
let k = line.find("UTC")
if k >= 0:
res = line[0..(k - 3)]
let k = res.rfind("</a>")
res = res[(k + 6)..^1]
break
echo if res.len > 0: res else: "No date/time found."
- Output:
20:59, 30 May 2020
Objeck
use Net;
use IO;
use Structure;
bundle Default {
class Scrape {
function : Main(args : String[]) ~ Nil {
client := HttpClient->New();
lines := client->Get("http://tycho.usno.navy.mil/cgi-bin/timer.pl", 80);
i := 0;
found := false;
while(found <> true & i < lines->Size()) {
line := lines->Get(i)->As(String);
index := line->Find("UTC");
if(index > -1) {
time := line->SubString(index - 9, 9)->Trim();
time->PrintLine();
found := true;
};
i += 1;
};
}
}
}
OCaml
let () =
let _,_, page_content = make_request ~url:Sys.argv.(1) ~kind:GET () in
let lines = Str.split (Str.regexp "\n") page_content in
let str =
List.find
(fun line ->
try ignore(Str.search_forward (Str.regexp "UTC") line 0); true
with Not_found -> false)
lines
in
let str = Str.global_replace (Str.regexp "<BR>") "" str in
print_endline str;
;;
There are libraries for this, but it's rather interesting to see how to use a socket to achieve this, so see the implementation of the above function make_request on this page.
ooRexx
This uses the RexxcURL wrapper for libcURL As an alternative the supplied rxSock socket library could be used
/* load the RexxcURL library */
Call RxFuncAdd 'CurlLoadFuncs', 'rexxcurl', 'CurlLoadFuncs'
Call CurlLoadFuncs
url = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
/* get a curl session */
curl = CurlInit()
if curl \= ''
then do
call CurlSetopt curl, 'URL', Url
if curlerror.intcode \= 0 then exit
call curlSetopt curl, 'OUTSTEM', 'stem.'
if curlerror.intcode \= 0 then exit
call CurlPerform curl
/* content is in a stem - lets get it all in a string */
content = stem.~allItems~makestring('l')
/* now parse out utc time */
parse var content content 'Universal Time' .
utcTime = content~substr(content~lastpos('<BR>') + 4)
say utcTime
end
Oz
declare
[Regex] = {Module.link ['x-oz://contrib/regex']}
fun {GetPage Url}
F = {New Open.file init(url:Url)}
Contents = {F read(list:$ size:all)}
in
{F close}
Contents
end
fun {GetDateString Doc}
case {Regex.search "<BR>([A-Za-z0-9:., ]+ UTC)" Doc}
of match(1:S#E ...) then {List.take {List.drop Doc S} E-S+1}
end
end
Url = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
in
{System.showInfo {GetDateString {GetPage Url}}}
Peloton
English dialect, short form, using integrated Rexx pattern matcher:
<@ DEFAREPRS>Rexx Parse</@>
<@ DEFPRSLIT>Rexx Parse|'<BR>' UTCtime 'UTC'</@>
<@ LETVARURL>timer|http://tycho.usno.navy.mil/cgi-bin/timer.pl</@>
<@ ACTRPNPRSVAR>Rexx Parse|timer</@>
<@ SAYVAR>UTCtime</@>
English dialect, padded variable-length form:
<# DEFINE WORKAREA PARSEVALUES>Rexx Parse</#>
<# DEFINE PARSEVALUES LITERAL>Rexx Parse|'<BR>' UTCtime 'UTC'</#>
<# LET VARIABLE URLSOURCE>timer|http://tycho.usno.navy.mil/cgi-bin/timer.pl</#>
<# ACT REPLACEBYPATTERN PARSEVALUES VARIABLE>Rexx Parse|timer</#>
<# SAY VARIABLE>UTCtime</#>
English dialect, padded short form, using string functions AFT and BEF:
<@ SAY AFT BEF URL LIT LIT LIT >http://tycho.usno.navy.mil/cgi-bin/timer.pl| UTC|<BR></@>
Perl
use LWP::Simple;
my $url = 'http://tycho.usno.navy.mil/cgi-bin/timer.pl';
get($url) =~ /<BR>(.+? UTC)/
and print "$1\n";
Phix
-- -- demo\rosetta\web_scrape.exw -- =========================== -- without js -- (libcurl) include builtins\libcurl.e include builtins\timedate.e object res = curl_easy_perform_ex("https://rosettacode.org/wiki/Talk:Web_scraping") if string(res) then res = split(res,'\n') for i=1 to length(res) do if not match(`<div id="siteNotice">`,res[i]) then -- (24/11/22, exclude notice) integer k = match("UTC",res[i]) if k then string line = res[i] -- (debug aid) res = line[1..k-3] k = rmatch("</a>",res) res = trim(res[k+5..$]) exit end if end if end for ?res if string(res) then timedate td = parse_date_string(res, {"hh:mm, d Mmmm yyyy"}) ?format_timedate(td,"Dddd Mmmm ddth yyyy h:mpm") end if else ?{"some error",res,curl_easy_strerror(res)} end if
- Output:
(From/as per talk page)
"20:53, 20 August 2008" "Wednesday August 20th 2008 8:53pm"
PHP
By iterating over each line:
<?
$contents = file('http://tycho.usno.navy.mil/cgi-bin/timer.pl');
foreach ($contents as $line){
if (($pos = strpos($line, ' UTC')) === false) continue;
echo subStr($line, 4, $pos - 4); //Prints something like "Dec. 06, 16:18:03"
break;
}
By regular expressions (
):
<?
echo preg_replace(
"/^.*<BR>(.*) UTC.*$/su",
"\\1",
file_get_contents('http://tycho.usno.navy.mil/cgi-bin/timer.pl')
);
PicoLisp
(load "@lib/http.l")
(client "tycho.usno.navy.mil" 80 "cgi-bin/timer.pl"
(when (from "<BR>")
(pack (trim (till "U"))) ) )
- Output:
-> "Feb. 19, 18:11:37"
PowerShell
$wc = New-Object Net.WebClient
$html = $wc.DownloadString('http://tycho.usno.navy.mil/cgi-bin/timer.pl')
$html -match ', (.*) UTC' | Out-Null
Write-Host $Matches[1]
fyi
.NET provides a property named UtcNow:
[System.DateTime]::UtcNow
- Output:
Wednesday, December 14, 2016 2:06:25 AM
I am currently in the Pacific timezone:
[System.DateTime]::Now
- Output:
Tuesday, December 13, 2016 6:06:25 PM
PureBasic
URLDownloadToFile_( #Null, "http://tycho.usno.navy.mil/cgi-bin/timer.pl", "timer.htm", 0, #Null)
ReadFile(0, "timer.htm")
While Not Eof(0) : Text$ + ReadString(0) : Wend
MessageRequester("Time", Mid(Text$, FindString(Text$, "UTC", 1) - 9 , 8))
Python
import urllib
page = urllib.urlopen('http://tycho.usno.navy.mil/cgi-bin/timer.pl')
for line in page:
if ' UTC' in line:
print line.strip()[4:]
break
page.close()
- Output:
Aug. 12, 15:22:08 UTC Universal Time
R
There are two ways of scraping data from webpages. You can either convert the page into an array of strings containing each line of HTML and use regular expressions to locate the useful data, or you can parse the HTML and use xPath to locate them. The first method is quicker for simpler pages, but may become more difficult for more complicated ones.
Regex method
Read the page as lines, find the line containing the string "UTC", then extract the portion of that string that is the date.
all_lines <- readLines("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
utc_line <- grep("UTC", all_lines, value = TRUE)
matched <- regexpr("(\\w{3}.*UTC)", utc_line)
utc_time_str <- substring(line, matched, matched + attr(matched, "match.length") - 1L)
The last three lines can be made simpler by using
library(stringr)
utc_line <- all_lines[str_detect(all_lines, "UTC")]
utc_time_str <- str_extract(utc_line, "\\w{3}.*UTC")
Finally, the date and time must be parsed and printed in the desired format.
utc_time <- strptime(utc_time_str, "%b. %d, %H:%M:%S UTC")
strftime(utc_time, "%A, %d %B %Y, %H:%M:%S")
Friday, 13 May 2011, 15:12:20
Parsing method
First, retrieve the web page. See HTTP_Request for more options with this.
library(RCurl)
web_page <- getURL("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
Now parse the html code into a tree and retrieve the pre node that contains interesting bit. Without xPath, the syntax is quite clunky.
library(XML)
page_tree <- htmlTreeParse(webpage)
times_node <- page_tree$children$html$children$body$children$h3$children$pre$children
times_node <- times_node[names(times_node) == "text"]
time_lines <- sapply(times_node, function(x) x$value)
Here, xPath simplifies things a little bit.
page_tree <- htmlTreeParse(web_page, useInternalNodes = TRUE)
times_node <- xpathSApply(page_tree, "//pre")[[1]]
times_node <- times_node[names(times_node) == "text"]
time_lines <- sapply(times_node, function(x) as(x, "character"))
Either way, the solution proceeds from here as in the regex method.
utc_line <- time_lines[str_detect(time_lines, "UTC")]
#etc.
Racket
#lang racket
(require net/url)
((compose1 car (curry regexp-match #rx"[^ <>][^<>]+ UTC")
port->string get-pure-port string->url)
"https://tycho.usno.navy.mil/cgi-bin/timer.pl")
Raku
(formerly Perl 6)
# 20210301 Updated Raku programming solution
use HTTP::Client; # https://github.com/supernovus/perl6-http-client/
#`[ Site inaccessible since 2019 ?
my $site = "http://tycho.usno.navy.mil/cgi-bin/timer.pl";
HTTP::Client.new.get($site).content.match(/'<BR>'( .+? <ws> UTC )/)[0].say
# ]
my $site = "https://www.utctime.net/";
my $matched = HTTP::Client.new.get($site).content.match(
/'<td>UTC</td><td>'( .*Z )'</td>'/
)[0];
say $matched;
#$matched = '12321321:412312312 123';
with DateTime.new($matched.Str) {
say 'The fetch result seems to be of a valid time format.'
} else {
CATCH { put .^name, ': ', .Str }
}
Note that the string between '<' and '>' refers to regex tokens, so to match a literal '<BR>' you need to quote it, while <ws> refers to the built-in token whitespace. Also, whitespace is ignored by default in Raku regexes.
- Output:
「2021-03-01T17:02:37Z」 The fetch result seems to be of a valid time format.
REBOL
REBOL [
Title: "Web Scraping"
URL: http://rosettacode.org/wiki/Web_Scraping
]
; Notice that REBOL understands unquoted URL's:
service: http://tycho.usno.navy.mil/cgi-bin/timer.pl
; The 'read' function can read from any data scheme that REBOL knows
; about, which includes web URLs. NOTE: Depending on your security
; settings, REBOL may ask you for permission to contact the service.
html: read service
; I parse the HTML to find the first <br> (note the unquoted HTML tag
; -- REBOL understands those too), then copy the current time from
; there to the "UTC" terminator.
; I have the "to end" in the parse rule so the parse will succeed.
; Not strictly necessary once I've got the time, but good practice.
parse html [thru <br> copy current thru "UTC" to end]
print ["Current UTC time:" current]
Ruby
A verbose example for comparison
require "open-uri"
open('http://tycho.usno.navy.mil/cgi-bin/timer.pl') do |p|
p.each_line do |line|
if line =~ /UTC/
puts line.match(/ (\d{1,2}:\d{1,2}:\d{1,2}) /)
break
end
end
end
A more concise example
require 'open-uri'
puts URI.parse('http://tycho.usno.navy.mil/cgi-bin/timer.pl').read.match(/ (\d{1,2}:\d{1,2}:\d{1,2}) UTC/)[1]
Run BASIC
print word$(word$(httpget$("http://tycho.usno.navy.mil/cgi-bin/timer.pl"),1,"UTC"),2,"<BR>")
- Output:
May. 09, 16:13:44
Rust
// 202100302 Rust programming solution
use std::io::Read;
use regex::Regex;
fn main() {
let client = reqwest::blocking::Client::new();
let site = "https://www.utctime.net/";
let mut res = client.get(site).send().unwrap();
let mut body = String::new();
res.read_to_string(&mut body).unwrap();
let re = Regex::new(r#"<td>UTC</td><td>(.*Z)</td>"#).unwrap();
let caps = re.captures(&body).unwrap();
println!("Result : {:?}", caps.get(1).unwrap().as_str());
}
- Output:
Result : "2021-03-02T16:27:02Z"
Scala
import scala.io.Source
object WebTime extends Application {
val text = Source.fromURL("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
val utc = text.getLines.find(_.contains("UTC"))
utc match {
case Some(s) => println(s.substring(4))
case _ => println("error")
}
}
Scheme
; Use the regular expression module to parse the url
(use-modules (ice-9 regex) (ice-9 rdelim))
; Variable to store result
(define time "")
; Set the url and parse the hostname, port, and path into variables
(define url "http://tycho.usno.navy.mil/cgi-bin/timer.pl")
(define r (make-regexp "^(http://)?([^:/]+)(:)?(([0-9])+)?(/.*)?" regexp/icase))
(define host (match:substring (regexp-exec r url) 2))
(define port (match:substring (regexp-exec r url) 4))
(define path (match:substring (regexp-exec r url) 6))
; Set port to 80 if it wasn't set above and convert from a string to a number
(if (eq? port #f) (define port "80"))
(define port (string->number port))
; Connect to remote host on specified port
(let ((s (socket PF_INET SOCK_STREAM 0)))
(connect s AF_INET (car (hostent:addr-list (gethostbyname host))) port)
; Send a HTTP request for the specified path
(display "GET " s)
(display path s)
(display " HTTP/1.0\r\n\r\n" s)
(set! r (make-regexp "<BR>(.+? UTC)"))
(do ((line (read-line s) (read-line s))) ((eof-object? line))
(if (regexp-match? (regexp-exec r line))
(set! time (match:substring (regexp-exec r line) 1)))))
; Display result
(display time)
(newline)
Seed7
$ include "seed7_05.s7i";
include "gethttp.s7i";
const proc: main is func
local
var string: pageWithTime is "";
var integer: posOfUTC is 0;
var integer: posOfBR is 0;
var string: timeStri is "";
begin
pageWithTime := getHttp("tycho.usno.navy.mil/cgi-bin/timer.pl");
posOfUTC := pos(pageWithTime, "UTC");
if posOfUTC <> 0 then
posOfBR := rpos(pageWithTime, "<BR>", posOfUTC);
if posOfBR <> 0 then
timeStri := pageWithTime[posOfBR + 4 .. pred(posOfUTC)];
writeln(timeStri);
end if;
end if;
end func;
Sidef
var ua = frequire('LWP::Simple');
var url = 'http://tycho.usno.navy.mil/cgi-bin/timer.pl';
var match = /<BR>(.+? UTC)/.match(ua.get(url));
say match[0] if match;
- Output:
Oct. 27, 00:20:50 UTC
Standard ML
Done in PolyML, needs fetch and sed. Basically the same as the function in PPM_conversion_through_a_pipe#Standard_ML.
val getTime = fn url =>
let
val fname = "/tmp/fConv" ^ (String.extract (Time.toString (Posix.ProcEnv.time()),7,NONE) );
val shellCommand = " fetch -o - \""^ url ^"\" | sed -ne 's/^.*alt=.Los Angeles:\\(.* (Daylight Saving)\\).*$/\\1/p' " ;
val me = ( Posix.FileSys.mkfifo
(fname,
Posix.FileSys.S.flags [ Posix.FileSys.S.irusr,Posix.FileSys.S.iwusr ]
) ;
Posix.Process.fork ()
)
in
if (Option.isSome me) then
let
val fin =TextIO.openIn fname
in
( Posix.Process.sleep (Time.fromReal 0.5) ;
TextIO.inputLine fin before
(TextIO.closeIn fin ; OS.FileSys.remove fname )
)
end
else
( OS.Process.system ( shellCommand ^ " > " ^ fname ^ " 2>&1 " ) ;
SOME "" before OS.Process.exit OS.Process.success
)
end;
print ( valOf (getTime "http://www.time.org"));
output
11:12 AM (PDT) (Daylight Saving)
Tcl
http and regular expressions
package require http
set request [http::geturl "http://tycho.usno.navy.mil/cgi-bin/timer.pl"]
if {[regexp -line {<BR>(.* UTC)} [http::data $request] --> utc]} {
puts $utc
}
curl(1) and list operations
Considering the web resource returns tabular data wrapped in a <PRE> tag, you can use Tcl's list processing commands to process its contents.
set data [exec curl -s http://tycho.usno.navy.mil/cgi-bin/timer.pl]
puts [lrange [lsearch -glob -inline [split $data <BR>] *UTC*] 0 3]
ToffeeScript
e, page = require('request').get! 'http://tycho.usno.navy.mil/cgi-bin/timer.pl'
l = line for line in page.body.split('\n') when line.indexOf('UTC')>0
console.log l.substr(4,l.length-20)
TUSCRIPT
$$ MODE TUSCRIPT
SET time = REQUEST ("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
SET utc = FILTER (time,":*UTC*:",-)
TXR
Robust
Large amounts of the document are matched (in fact the entire thing!), rather than blindly looking for some small amount of context.
If the web page changes too much, the query will fail to match. TXR will print the word "false" and terminate with a failed exit status. This is preferrable to finding a false positive match and printing a wrong result. (E.g. any random garbage that happened to be in a line of HTML accidentally containing the string UTC).
@(next @(open-command "wget -c http://tycho.usno.navy.mil/cgi-bin/timer.pl -O - 2> /dev/null"))
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final"//EN>
<html>
<body>
<TITLE>What time is it?</TITLE>
<H2> US Naval Observatory Master Clock Time</H2> <H3><PRE>
@(collect :vars (MO DD HH MM SS (PM " ") TZ TZNAME))
<BR>@MO. @DD, @HH:@MM:@SS @(maybe)@{PM /PM/} @(end)@TZ@/\t+/@TZNAME
@ (until)
</PRE>@/.*/
@(end)
</PRE></H3><P><A HREF="http://www.usno.navy.mil"> US Naval Observatory</A>
</body></html>
@(output)
@ (repeat)
@MO-@DD @HH:@MM:@SS @PM @TZ
@ (end)
@(end)
Sample run:
$ txr navytime.txr Nov-22 22:49:41 UTC Nov-22 05:49:41 PM EST Nov-22 04:49:41 PM CST Nov-22 03:49:41 PM MST Nov-22 02:49:41 PM PST Nov-22 01:49:41 PM AKST Nov-22 12:49:41 PM HAST
Get just the UTC time:
$ txr -DTZ=UTC navytime.txr Nov-22 22:50:16 UTC
Naive
Skip stuff until a line beginning with <BR>
has some stuff before "UTC", and capture that stuff:
@(next @(open-command "wget -c http://tycho.usno.navy.mil/cgi-bin/timer.pl -O - 2> /dev/null"))
@(skip)
<BR>@time@\ UTC@(skip)
@(output)
@time
@(end)
UNIX Shell
This solution uses 'curl' and the standard POSIX command 'sed'.
#!/bin/sh
curl -s http://tycho.usno.navy.mil/cgi-bin/timer.pl |
sed -ne 's/^<BR>\(.* UTC\).*$/\1/p'
This solution uses tcsh, wget and awk
#!/usr/bin/tcsh -f
set page = `wget -q -O- "http://tycho.usno.navy.mil/cgi-bin/timer.pl"`
echo `awk -v s="${page[22]}" 'BEGIN{print substr(s,5,length(s))}'` ${page[23]} ${page[24]}
Ursala
This works by launching the wget command in a separate process and capturing its output. The program is compiled to an executable command.
#import std
#import cli
#executable ('parameterized','')
whatime =
<.file$[contents: --<''>]>+ -+
@hm skip/*4+ ~=(9%cOi&)-~l*+ *~ ~&K3/'UTC',
(ask bash)/0+ -[wget -O - http://tycho.usno.navy.mil/cgi-bin/timer.pl]-!+-
Here is a bash session.
$ whatime Jun. 26, 20:49:52 UTC
VBA
Note For this example I altered the VBScript
Rem add Microsoft VBScript Regular Expression X.X to your Tools References
Function GetUTC() As String
Url = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
With CreateObject("MSXML2.XMLHTTP.6.0")
.Open "GET", Url, False
.send
arrt = Split(.responseText, vbLf)
End With
For Each t In arrt
If InStr(t, "UTC") Then
GetUTC = StripHttpTags(t)
Exit For
End If
Next
End Function
Function StripHttpTags(s)
With New RegExp
.Global = True
.Pattern = "\<.+?\>"
If .Test(s) Then
StripHttpTags = .Replace(s, "")
Else
StripHttpTags = s
End If
End With
End Function
Sub getTime()
Rem starting point
Dim ReturnValue As String
ReturnValue = GetUTC
Rem debug.print can be removed
Debug.Print ReturnValue
MsgBox (ReturnValue)
End Sub
- Output:
Run getTime Subroutine Mar. 05, 00:57:37 UTC Universal Time
VBScript
Function GetUTC() As String
Url = "http://tycho.usno.navy.mil/cgi-bin/timer.pl"
With CreateObject("MSXML2.XMLHTTP.6.0")
.Open "GET", Url, False
.send
arrt = Split(.responseText, vbLf)
End With
For Each t In arrt
If InStr(t, "UTC") Then
GetUTC = StripHttpTags(t)
Exit For
End If
Next
End Function
Function StripHttpTags(s)
With New RegExp
.Global = True
.Pattern = "\<.+?\>"
If .Test(s) Then
StripHttpTags = .Replace(s, "")
Else
StripHttpTags = s
End If
End With
End Function
WScript.StdOut.Write GetUTC
WScript.StdOut.WriteLine
- Output:
Run getTime Subroutine Apr. 21, 21:02:03 UTC Universal Time
Visual Basic .NET
New, .NET way with StringReader:
Imports System.Net
Imports System.IO
Dim client As WebClient = New WebClient()
Dim content As String = client.DownloadString("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
Dim sr As New StringReader(content)
While sr.peek <> -1
Dim s As String = sr.ReadLine
If s.Contains("UTC") Then
Dim time As String() = s.Substring(4).Split(vbTab)
Console.WriteLine(time(0))
End If
End While
Alternative, old fashioned way using VB "Split" function:
Imports System.Net
Dim client As WebClient = New WebClient()
Dim content As String = client.DownloadString("http://tycho.usno.navy.mil/cgi-bin/timer.pl")
Dim lines() As String = Split(content, vbLf) 'may need vbCrLf
For Each line In lines
If line.Contains("UTC") Then
Dim time As String() = line.Substring(4).Split(vbTab)
Console.WriteLine(time(0))
End If
Next
V (Vlang)
import net.http
import net.html
fn main() {
resp := http.get("https://www.utctime.net") or {println(err) exit(-1)}
html_doc := html.parse(resp.body)
utc := html_doc.get_tag("table").str().split("UTC</td><td>")[1].split("</td>")[0]
rfc_850 := html_doc.get_tag("table").str().split("RFC 850</td><td>")[1].split("</td>")[0]
println(utc)
println(rfc_850)
}
- Output:
2023-06-06T12:08:01Z Tuesday, 06-Jun-23 12:08:01 UTC
Wren
An embedded program so we can ask the C host to download the page for us. This task's talk page is being used for this purpose as the original URL no longer works.
The code is based in part on the C example though, as we don't have regex, we use our Pattern module to identify the first occurrence of a UTC date/time after the site notice.
/* 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 * 4
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)")
ix = html.indexOf("(UTC)", ix + 1) // skip the site notice
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)
We now embed this in the following C program, compile and run it.
/* gcc Web_scraping.c -o Web_scraping -lcurl -lwren -lm */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
#include "wren.h"
/* C <=> Wren interface functions */
char *url, *read_file, *write_file;
size_t bufsize;
size_t lr = 0;
size_t filterit(void *ptr, size_t size, size_t nmemb, void *stream) {
if ((lr + size*nmemb) > bufsize) return bufsize;
memcpy(stream+lr, ptr, size * nmemb);
lr += size * nmemb;
return size * nmemb;
}
void C_bufferAllocate(WrenVM* vm) {
bufsize = (int)wrenGetSlotDouble(vm, 1);
wrenSetSlotNewForeign(vm, 0, 0, bufsize);
}
void C_curlAllocate(WrenVM* vm) {
CURL** pcurl = (CURL**)wrenSetSlotNewForeign(vm, 0, 0, sizeof(CURL*));
*pcurl = curl_easy_init();
}
void C_value(WrenVM* vm) {
const char *s = (const char *)wrenGetSlotForeign(vm, 0);
wrenSetSlotString(vm, 0, s);
}
void C_easyPerform(WrenVM* vm) {
CURL* curl = *(CURL**)wrenGetSlotForeign(vm, 0);
curl_easy_perform(curl);
}
void C_easyCleanup(WrenVM* vm) {
CURL* curl = *(CURL**)wrenGetSlotForeign(vm, 0);
curl_easy_cleanup(curl);
}
void C_easySetOpt(WrenVM* vm) {
CURL* curl = *(CURL**)wrenGetSlotForeign(vm, 0);
CURLoption opt = (CURLoption)wrenGetSlotDouble(vm, 1);
if (opt < 10000) {
long lparam = (long)wrenGetSlotDouble(vm, 2);
curl_easy_setopt(curl, opt, lparam);
} else if (opt < 20000) {
if (opt == CURLOPT_WRITEDATA) {
char *buffer = (char *)wrenGetSlotForeign(vm, 2);
curl_easy_setopt(curl, opt, buffer);
} else if (opt == CURLOPT_URL) {
const char *url = wrenGetSlotString(vm, 2);
curl_easy_setopt(curl, opt, url);
}
} else if (opt < 30000) {
if (opt == CURLOPT_WRITEFUNCTION) {
curl_easy_setopt(curl, opt, &filterit);
}
}
}
WrenForeignClassMethods bindForeignClass(WrenVM* vm, const char* module, const char* className) {
WrenForeignClassMethods methods;
methods.allocate = NULL;
methods.finalize = NULL;
if (strcmp(module, "main") == 0) {
if (strcmp(className, "Buffer") == 0) {
methods.allocate = C_bufferAllocate;
} else if (strcmp(className, "Curl") == 0) {
methods.allocate = C_curlAllocate;
}
}
return methods;
}
WrenForeignMethodFn bindForeignMethod(
WrenVM* vm,
const char* module,
const char* className,
bool isStatic,
const char* signature) {
if (strcmp(module, "main") == 0) {
if (strcmp(className, "Buffer") == 0) {
if (!isStatic && strcmp(signature, "value") == 0) return C_value;
} else if (strcmp(className, "Curl") == 0) {
if (!isStatic && strcmp(signature, "easySetOpt(_,_)") == 0) return C_easySetOpt;
if (!isStatic && strcmp(signature, "easyPerform()") == 0) return C_easyPerform;
if (!isStatic && strcmp(signature, "easyCleanup()") == 0) return C_easyCleanup;
}
}
return NULL;
}
static void writeFn(WrenVM* vm, const char* text) {
printf("%s", text);
}
void errorFn(WrenVM* vm, WrenErrorType errorType, const char* module, const int line, const char* msg) {
switch (errorType) {
case WREN_ERROR_COMPILE:
printf("[%s line %d] [Error] %s\n", module, line, msg);
break;
case WREN_ERROR_STACK_TRACE:
printf("[%s line %d] in %s\n", module, line, msg);
break;
case WREN_ERROR_RUNTIME:
printf("[Runtime Error] %s\n", msg);
break;
}
}
char *readFile(const char *fileName) {
FILE *f = fopen(fileName, "r");
fseek(f, 0, SEEK_END);
long fsize = ftell(f);
rewind(f);
char *script = malloc(fsize + 1);
fread(script, 1, fsize, f);
fclose(f);
script[fsize] = 0;
return script;
}
static void loadModuleComplete(WrenVM* vm, const char* module, WrenLoadModuleResult result) {
if( result.source) free((void*)result.source);
}
WrenLoadModuleResult loadModule(WrenVM* vm, const char* name) {
WrenLoadModuleResult result = {0};
if (strcmp(name, "random") != 0 && strcmp(name, "meta") != 0) {
result.onComplete = loadModuleComplete;
char fullName[strlen(name) + 6];
strcpy(fullName, name);
strcat(fullName, ".wren");
result.source = readFile(fullName);
}
return result;
}
int main(int argc, char **argv) {
WrenConfiguration config;
wrenInitConfiguration(&config);
config.writeFn = &writeFn;
config.errorFn = &errorFn;
config.bindForeignClassFn = &bindForeignClass;
config.bindForeignMethodFn = &bindForeignMethod;
config.loadModuleFn = &loadModule;
WrenVM* vm = wrenNewVM(&config);
const char* module = "main";
const char* fileName = "Web_scraping.wren";
char *script = readFile(fileName);
WrenInterpretResult result = wrenInterpret(vm, module, script);
switch (result) {
case WREN_RESULT_COMPILE_ERROR:
printf("Compile Error!\n");
break;
case WREN_RESULT_RUNTIME_ERROR:
printf("Runtime Error!\n");
break;
case WREN_RESULT_SUCCESS:
break;
}
wrenFreeVM(vm);
free(script);
return 0;
}
- Output:
20:53, 20 August 2008
Xidel
http://videlibri.sourceforge.net/xidel.html
$ xidel -s "https://www.rosettacode.org/wiki/Talk:Web_scraping" -e '
//p[1]/text()[last()]
'
20:53, 20 August 2008 (UTC)
$ xidel -s "https://www.rosettacode.org/wiki/Talk:Web_scraping" -e '
x:parse-dateTime(//p[1]/text()[last()],'hh:nn, dd mmmm yyyy')
'
2008-08-20T20:53:00
$ xidel -s "https://www.rosettacode.org/wiki/Talk:Web_scraping" -e '
adjust-dateTime-to-timezone(
x:parse-dateTime(//p[1]/text()[last()],'hh:nn, dd mmmm yyyy'),
dayTimeDuration('PT0H')
)
'
$ xidel -s "https://www.rosettacode.org/wiki/Talk:Web_scraping" -e '
x:parse-dateTime(//p[1]/text()[last()],'hh:nn, dd mmmm yyyy')
! adjust-dateTime-to-timezone(.,dayTimeDuration('PT0H'))
'
$ xidel -s "https://www.rosettacode.org/wiki/Talk:Web_scraping" -e '
x:parse-dateTime(//p[1]/text()[last()],'hh:nn, dd mmmm yyyy')
=> adjust-dateTime-to-timezone(dayTimeDuration('PT0H'))
'
2008-08-20T20:53:00Z
zkl
const HOST="tycho.usno.navy.mil", PORT=80, dir="/cgi-bin/timer.pl";
get:="GET %s HTTP/1.0\r\nHost: %s:%s\r\n\r\n".fmt(dir,HOST,PORT);
server:=Network.TCPClientSocket.connectTo(HOST,PORT);
server.write(get); // send request to web serer
data:=server.read(True); // read data from web server
data.seek(data.find("UTC")); // middle of line
c:=data.seek(Void,0); // start of line
line:=data[c,data.seek(Void,1)-c].text;
line.print(); // the HTML UTC line
re:=RegExp(0'|.*(\d\d:\d\d:\d\d)|); // get time
re.search(line);
re.matched[1].println();
- Output:
<BR>Mar. 18, 06:18:31 UTC Universal Time 06:18:31
- Programming Tasks
- Networking and Web Interaction
- Input Output
- ACL2/Omit
- Batch File/Omit
- Locomotive Basic/Omit
- Lotus 123 Macro Scripting/Omit
- M4/Omit
- Maxima/Omit
- Openscad/Omit
- PARI/GP/Omit
- PostScript/Omit
- Retro/Omit
- ZX Spectrum Basic/Omit
- 8th
- Ada
- AWS
- ALGOL 68
- App Inventor
- AppleScript
- AutoHotkey
- AWK
- BBC BASIC
- C
- Libcurl
- C sharp
- C++
- Boost
- Caché ObjectScript
- Ceylon
- Clojure
- CoffeeScript
- Common Lisp
- Cl-ppcre
- DRAKMA
- D
- Delphi
- E
- Erlang
- F Sharp
- Factor
- Forth
- FunL
- Gambas
- Go
- Groovy
- Haskell
- Icon
- Unicon
- J
- Java
- JavaScript
- Jq
- Julia
- Kotlin
- Lasso
- Liberty BASIC
- Lua
- LuaSocket
- M2000 Interpreter
- Maple
- Mathematica
- Wolfram Language
- MATLAB
- Octave
- Microsoft Small Basic
- MIRC Scripting Language
- NetRexx
- Nim
- Objeck
- OCaml
- OoRexx
- Oz
- Peloton
- Perl
- LWP
- Phix
- Phix/libcurl
- PHP
- PicoLisp
- PowerShell
- PureBasic
- Python
- R
- Stringr
- RCurl
- XML
- Racket
- Raku
- REBOL
- Ruby
- Run BASIC
- Rust
- Scala
- Scheme
- Seed7
- Sidef
- Standard ML
- Tcl
- ToffeeScript
- TUSCRIPT
- TXR
- UNIX Shell
- Ursala
- TI-83 BASIC/Omit
- TI-89 BASIC/Omit
- VBA
- VBScript
- Visual Basic .NET
- V (Vlang)
- Wren
- Wren-pattern
- Xidel
- Zkl