A variety of tutorials, comment and other writing aimed at web developershttp://andylangton.co.uk/articles/Copyright Blog / Andy Langton's WebsiteEvery now and then I use a port scanner on computers I work with to check which services are accepting connections from the internet. For a typical client PC, there should normally be no ports accessible, and for a server, only those ports specifically enabled for services. Imagine my surprise when scanning a server recently to notice that in addition to the ports specifically open, also open were port 8080 and port 3128. Both are ports commonly used by HTTP proxies, and as a result also commonly used by trojans. So, into trojan scanning mode I went only to find nothing. I also checked the router, which was blocking connections to those ports, and the software firewall which also had no rules that would enable these connections. So was it some kind of uber-stealth trojan? After a lot of hassle and some amount of worry, it dawned on me that if there was genuinely no program listening on those ports, it must be at the ISP level. Virgin Media was probably opening these ports (and if you ask me, exposing their clients to unnecessary attention from hackers scanning for vulnerabilities. With a bit of Googling, I found a number of references to those ports as being part of a web caching system in use by Virgin Media (see http://ben.cheetham.me.uk/resources/net/ntl-proxy-list, for example). Bah. Curse you Virgin! For anyone else curious about these open ports on a Virgin Media connected computer, hopefully this post will save you the time I just spent ;)Mon, 18 Jan 2010 18:38:51 +0000http://andylangton.co.uk/articles/it-security/virgin-media-ports-3128-and-8080/http://andylangton.co.uk/articles/it-security/virgin-media-ports-3128-and-8080/Or: What is it with all of the weird Google Books/YouTube results? Thu, 16 Jul 2009 21:02:55 +0000http://andylangton.co.uk/articles/seo/breaking-google-with-advanced-operators/http://andylangton.co.uk/articles/seo/breaking-google-with-advanced-operators/All of the major search engines recently agreed on an element to address the problems webmasters experience related to duplicate content. I feel their pain, and while I dislike proprietary features (since they don't address the underlying problem) it seems like it might be a useful tool in certain circumstances.Tue, 17 Feb 2009 18:20:13 +0000http://andylangton.co.uk/articles/seo/does-rel-canonical-work/http://andylangton.co.uk/articles/seo/does-rel-canonical-work/While Amazon are not the worst culprits, they sent me an email today which illustrates how larger organisations are failing to help their users protect themselves against phishing emails.Sat, 22 Nov 2008 15:39:04 +0000http://andylangton.co.uk/articles/it-security/amazon-phishing-emails/http://andylangton.co.uk/articles/it-security/amazon-phishing-emails/Hiding a single element with Jquery was pretty straightforward. But what about if you want to show/hide multiple elements independently?Mon, 13 Oct 2008 18:52:56 +0000http://andylangton.co.uk/articles/javascript/jquery-show-hide-multiple-elements/http://andylangton.co.uk/articles/javascript/jquery-show-hide-multiple-elements/url_get_contents - a function to retrieve the contents of a remote URL with PHP and the cURL library.Tue, 03 Jun 2008 22:17:21 +0000http://andylangton.co.uk/articles/php/use-curl-to-retrieve-url-contents-with-a-few-options/http://andylangton.co.uk/articles/php/use-curl-to-retrieve-url-contents-with-a-few-options/Philosophy is probably my second most common reading material. But yes, Sartre is terrifically boring.Tue, 03 Jun 2008 21:09:34 +0000http://andylangton.co.uk/articles/philosophy/learn-philosophy-from-a-joke-book/http://andylangton.co.uk/articles/philosophy/learn-philosophy-from-a-joke-book/Update: Show/hide multiple elements independently I'm a big fan of jquery since I don't often need to write any javascript, but for the times I do it cuts out most of the hassle of accessing on page elements, using CSS selectors and really helps with an accessible approach.Sat, 17 May 2008 13:30:00 +0000http://andylangton.co.uk/articles/javascript/jquery-accessible-show-hide/http://andylangton.co.uk/articles/javascript/jquery-accessible-show-hide/As I suppose quite a few people did, I signed up for the beta of Persai as a reader of the now defunct uncov. I imagine that gives them a fairly direct batch of beta testers, all over-fond of the word 'fail'. I've used it solely from an end-user point of view: I haven't done any testing to try to figure out the technology yet.Sat, 17 May 2008 12:45:00 +0000http://andylangton.co.uk/articles/startups-betas/persai-dull-but-effective/http://andylangton.co.uk/articles/startups-betas/persai-dull-but-effective/I recently went shopping for some home-recording equipment, and thought I'd share my experience and give credit where it's due. Online merchants note - a little bit of friendly customer service goes a long way.Fri, 02 May 2008 20:40:44 +0000http://andylangton.co.uk/articles/ecommerce/andertons-music-highly-recommended-ux2-great/http://andylangton.co.uk/articles/ecommerce/andertons-music-highly-recommended-ux2-great/I just discovered the Apache module mod_speling (yup, one 'l') which is a fantastic way to ensure visitors who mistype URIs get automatically redirected to the correct location.Mon, 30 Apr 2007 20:04:23 +0000http://andylangton.co.uk/articles/apache/use-modspeling-to-fix-mistyped-uris/http://andylangton.co.uk/articles/apache/use-modspeling-to-fix-mistyped-uris/While finding out monitor resolution with javascript can be useful for statistics and certain other applications, often the need is to determine how much space is available within the browser window.Thu, 12 Apr 2007 19:27:47 +0000http://andylangton.co.uk/articles/javascript/get-viewport-size-javascript/http://andylangton.co.uk/articles/javascript/get-viewport-size-javascript/If you want to permanently redirect a small number of URIs, or redirect based on conditions defined in PHP, then you need a permanent PHP redirect.Fri, 30 Mar 2007 18:46:00 +0000http://andylangton.co.uk/articles/php/permanent-redirects-with-php/http://andylangton.co.uk/articles/php/permanent-redirects-with-php/Find out and display a user's screen resolution with javascript.Wed, 28 Mar 2007 00:15:16 +0000http://andylangton.co.uk/articles/javascript/browser-screen-resolution/http://andylangton.co.uk/articles/javascript/browser-screen-resolution/The ability to change a visitors scrollbars actually uses CSS rather than javascript.Mon, 26 Mar 2007 15:48:33 +0000http://andylangton.co.uk/articles/css/javascript-css-scrollbars/http://andylangton.co.uk/articles/css/javascript-css-scrollbars/Historically, javascript has been 'hidden' from search engines; their spiders did not understand javascript and could not interpret even the most basic of javascript code.Thu, 01 Mar 2007 22:33:12 +0000http://andylangton.co.uk/articles/javascript/javascript-and-spiders/http://andylangton.co.uk/articles/javascript/javascript-and-spiders/Redirecting a visitor with javascript is pretty straightforward. The simplest way is to use one of the methods below.Fri, 23 Feb 2007 10:45:36 +0000http://andylangton.co.uk/articles/javascript/javascript-redirect-scripts/http://andylangton.co.uk/articles/javascript/javascript-redirect-scripts/I'm not a big fan of forcing users to see things 'my way' but a client recently wanted to use a wacky font for headings, and was only concerned with viewers using IE. (Whether this is a good idea or not is for a different discussion!)Thu, 22 Feb 2007 18:43:26 +0000http://andylangton.co.uk/articles/css/embedding-fonts-with-css-ie-only/http://andylangton.co.uk/articles/css/embedding-fonts-with-css-ie-only/The Search Result Preview tool has been updated so you can see changes 'live' via javascriptThu, 22 Feb 2007 18:33:35 +0000http://andylangton.co.uk/articles/seo/preview-tool-updated/http://andylangton.co.uk/articles/seo/preview-tool-updated/Is Opera better than Firefox? Update: And is IE7 better than either of them?Wed, 21 Feb 2007 23:07:02 +0000http://andylangton.co.uk/articles/misc/opera-vs-firefox/http://andylangton.co.uk/articles/misc/opera-vs-firefox/Reload/refresh a page with javascript To reload or refresh the current page with javascript, you can use the reload() function.Wed, 21 Feb 2007 19:09:15 +0000http://andylangton.co.uk/articles/javascript/javascript-location-reload/http://andylangton.co.uk/articles/javascript/javascript-location-reload/This simple script will prevent javascript errors from being displayed in your visitor's browserWed, 21 Feb 2007 19:08:18 +0000http://andylangton.co.uk/articles/javascript/disable-javascript-errors/http://andylangton.co.uk/articles/javascript/disable-javascript-errors/This simple script operates the same way as the back button in a visitor's browser.Wed, 21 Feb 2007 19:07:07 +0000http://andylangton.co.uk/articles/javascript/javascript-back-button/http://andylangton.co.uk/articles/javascript/javascript-back-button/Javascripts allows you to popup a small box of text, rather like the error and information message boxes within windoze.Wed, 21 Feb 2007 17:23:19 +0000http://andylangton.co.uk/articles/javascript/javascript-alert/http://andylangton.co.uk/articles/javascript/javascript-alert/