Tag Archive

The Perishable Press 4G Blacklist

Update: Check out the new and improved 6G Firewall 2016! At last! After many months of collecting data, crafting directives, and testing results, I am thrilled to announce the release of the 4G Blacklist! The 4G Blacklist is a next-generation protective firewall that secures your website against a wide range of malicious activity. Like its 3G predecessor, the 4G Blacklist is designed for use on Apache servers and is easily implemented via HTAccess or the httpd.conf configuration file. In order to function properly, the 4G Blacklist requires two specific Apache modules, mod_rewrite and mod_alias. As with the third generation of […] Read more »

Building the Perishable Press 4G Blacklist

Last year, after much research and discussion, I built a concise, lightweight security strategy for Apache-powered websites. Prior to the development of this strategy, I relied on several extensive blacklists to protect my sites against malicious user agents and IP addresses. Unfortunately, these mega-lists eventually became unmanageable and ineffective. As increasing numbers of attacks hit my server, I began developing new techniques for defending against external threats. This work soon culminated in the release of a “next-generation” blacklist that works by targeting common elements of decentralized server attacks. Consisting of a mere 37 lines, this “2G” Blacklist provided enough protection […] Read more »

Remove the WWW Prefix for all URLs via PHP

Canonical URLs are important for maintaining consistent linkage, reducing duplicate content issues, and increasing the overall integrity of your site. In addition to cleaning up trailing slashes and removing extraneous index.php and index.html strings, removing the www subdirectory prefix is an excellent way to shorten links and deliver consistent, canonical URLs. Of course, an optimal way of removing (or adding) the www prefix is accomplished via HTAccess canonicalization: Read more »

Unobtrusive JavaScript for ‘Print-This’ Links

One of the oldest JavaScript tricks in the book involves providing a “print this!” link for visitors that enables them to summon their operating system’s default print dialogue box to facilitate quick and easy printing of whatever page they happen to be viewing. With the old way of pulling this little stunt, we write this in the markup comprising the target “print this!” link in question: <a href=”javascript:window.print()”>Print This!</a> Big yuck there, of course, due to the obtrusive nature of the JavaScript implementation. Adhering to the principles of proper Web Standards, it is better practice to separate behavior from structure […] Read more »

Cross-Browser Transparency via CSS

Shortest post ever! You can quickly and easily apply transparency to any supportive element by adding the following CSS code your stylesheet: selector { filter: alpha(opacity=50); /* internet explorer */ -khtml-opacity: 0.5; /* khtml, old safari */ -moz-opacity: 0.5; /* mozilla, netscape */ opacity: 0.5; /* fx, safari, opera */ } Check the code comments to see what’s doing what, and feel free to adjust the level of transparency by editing the various property values. Also, remember to replace “selector” with the target element of your choice. By the way, I’ve got a metric tonne of juicy CSS posts scheduled […] Read more »

Better Image Caching with CSS

I have written previously on the fine art of preloading images without JavaScript using only CSS. These caching techniques have evolved in terms of effectiveness and accuracy, but may be improved further to allow for greater cross-browser functionality. In this post, I share a “CSS-only” preloading method that works better under a broader set of conditions. Previous image-preloading techniques target all browsers, devices, and media types. Unfortunately, certain browsers do not load images that are hidden directly (via the <img /> element) or indirectly (e.g., via the parent <div></div> element) using either display:none; or visibility:hidden;. Further problematic is the potential […] Read more »

Temporary PHP Redirect: Allow Multiple IP Access and Redirect Everyone Else

In my previous article on temporarily redirecting visitors during site updates, I present numerous PHP and HTAccess methods for handling traffic during site maintenance, updates, and other temporary periods of downtime. Each of the PHP methods presented in the article allow for access from a single IP while redirecting everyone else. In this article, we modify our previous techniques to allow access for multiple IP addresses while temporarily redirecting everyone else to the page of our choice. Plus, while we’re at it, we’ll explore a few additional ways to adapt and use the general technique. Read more »

The Halving Method of Identifying Problematic Code

Working a great deal with blacklists, I am frequently trying to isolate and identify problematic code. For example, a blacklist implementation may suddenly prevent a certain type of page from loading. In order to resolve the issue, the blacklist is immediately removed and tested for the offending directive(s). This situation is common to other coding languages as well, especially when dealing with CSS. Identifying problem code is more of an art form than a science, but fortunately, there are a few ways to improve your overall code-sleuthing strategy. Read more »

New and Improved JavaScript Clock

Earlier this year, I posted an article explaining how to implement an unobtrusive JavaScript dynamic clock. While not completely earth-shattering or cutting-edge or anything like that, the dynamic JavaScript clock has received some great feedback from users who found the script to be exactly what they were looking for. In fact, a couple of weeks ago, Bill Brown went above and beyond by taking the time to improve the script with some great new features, including a “blinking seconds separator (for kicks)” and removal of “the need for the noscript tag.” Here is the complete script sent by Bill in […] Read more »

Redirect All (Broken) Links from any Domain via HTAccess

Here’s the scene: you have been noticing a large number of 404 requests coming from a particular domain. You check it out and realize that the domain in question has a number of misdirected links to your site. The links may resemble legitimate URLs, but because of typographical errors, markup errors, or outdated references, they are broken, leading to nowhere on your site and producing a nice 404 error for every request. Ugh. Or, another painful scenario would be a single broken link on a highly popular site. For example, you may have one of your best posts mentioned in […] Read more »

Feedburner Alternative: Homegrown Feed Statistics for Your Blog

If, for whatever reason, you don’t want to use Feedburner to track your feed statistics, this article describes a relatively simple, “roll-your-own” alternative. Instead of redirecting your feed traffic through Feedburner, keep your original feed URLs and place the following code into a file named “feed_stats.php” (or whatever) and upload to your server: Read more »

WordPress Custom Fields, Part II: Tips and Tricks

As we have seen in our previous post, WordPress Custom Fields Part I, custom fields provide an excellent way to add flexible content to your posts and pages. By assigning various types of content to different custom fields, you gain complete control over when, where, and how to display the associated information. For example, sub-headings may be displayed in the sidebar, footnotes may be consolidated into a single region, post images may be displayed before the post title, and so on. In this follow-up article, we will review the basics of custom fields and then jump into a few custom-field […] Read more »

Unobtrusive JavaScript: 5 Ways to Remove Unwanted Focus Outlines

I recently wrote about how to remove unwanted link outlines using a pure-CSS method that works on every modern browser except (wait for it) ..Internet Explorer 6! Yes, that’s right, another reason why (almost) everyone is pushing hard to eliminate Internet Explorer from existence. Nonetheless, removing those pesky unwanted link outlines in IE6 is not possible with CSS, but it’s a snap with a little JavaScript. Here are four unobtrusive JavaScript techniques (plus one CSS-only method thrown in for good measure) for removing unwanted focus outlines. Read more »

Miscellaneous Code Snippets for WordPress, Windows, and Firefox

One of the original purposes of Perishable Press involved serving as a “virtual dumpster” for all of my miscellaneous code snippets. Over time, I continued elaborating to greater degrees on the various code recipes that I was posting, until eventually those brief snippet posts evolved into complete, richly detailed articles (at least from my point of view). Now that I enjoy the luxury of writing for an incredible audience, I try to avoid posting anything that doesn’t include an accompanying explanation. “If it’s worth posting, it’s worth explaining,” I always say. When you have people reading your stuff, there is […] Read more »

Perfect WordPress Title Tags Redux

In my previous article on WordPress title tags, How to Generate Perfect WordPress Title Tags without a Plugin, We explore everything needed to create perfect titles for your WordPress-powered site. After discussing the functionality and implementation of various code examples, the article concludes with a “perfect” title-tag script that covers all the bases. Or so I thought.. Some time after the article had been posted, Mat8iou chimed in with a couple of ways to improve thie script by cleaning up tag names and specifying page numbers for archive views. Apparently, by replacing the $tag variable with WordPress’ built-in single_tag_title();, titles […] Read more »

Valid, SEO-Friendly Post Translation Links

Ever wanted to provide automatic language translations of your web pages without installing another plugin? Here is a valid, SEO-friendly technique that takes advantage of Google’s free translation service. All you need is a PHP-enabled server and you’re good to go. Just copy and paste the following code into the desired location in your page template and enjoy the results. Once in place, this code will produce translation links for eight common languages for every page on your site. Grab, gulp and go: Read more »