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260 posts related to: Online Tools for Traceroute & Ping

Stop WordPress from Leaking PageRank to Admin Pages

During the most recent Perishable Press redesign, I noticed that several of my WordPress admin pages had been assigned significant levels of PageRank. Not good. After some investigation, I realized that my ancient robots.txt rules were insufficient in preventing Google from indexing various WordPress admin pages. Specifically, the following pages have been indexed and subsequently assigned PageRank: Continue reading »

Eliminate 404 Errors for PHP Functions

Recently, I discussed the suspicious behavior recently observed by the Yahoo! Slurp crawler. As revealed by the site’s closely watched 404-error logs, Yahoo! had been requesting a series of nonexistent resources. Although a majority of the 404 errors were exclusive to the Slurp crawler, there were several instances of requests that were also coming from Google, Live, and even Ask. Initially, these distinct errors were misdiagnosed as existing URLs appended with various JavaScript functions. Here are a few typical examples […] Continue reading »

Super Loop: Exclude Specific Categories and Display any Number of Posts

[ Image: Detail view of a series of mechanical gears (black and white photo) ]

Readers occasionally ask for help with their WordPress loops. Usually, these requests involve modifying the loop with some customized functionality. Frequently, such customization involves one of these popular behaviors: Continue reading »

Temporary Site Redirect for Visitors during Site Updates

[ Image: Abstract Mathematical Diagram ]

In our article Stupid htaccess Tricks, we present the htaccess code required for redirecting visitors temporarily during periods of site maintenance. Although the article provides everything needed to implement the temporary redirect, I think readers would benefit from a more thorough examination of the process — nothing too serious, just enough to get it right. After discussing temporary redirects via htaccess, I’ll also explain how to accomplish the same thing using only a small slice of PHP. It’s like two […] Continue reading »

MySQL Magic: Find and Replace Data

Recently, I needed to find and replace all instances of “http://website” in the wp_comments table of the WordPress database. Fortunately, SQL provides a simple way to find and replace data with its wonderful UPDATE function. Continue reading »

Another Mystery Solved..

Recently, after researching comment links for an upcoming article, I realized that my default <input /> values were being submitted as the URL for all comments left without associated website information. During the most recent site redesign, I made the mistake of doing this in comments.php: … <input class="input" name="url" id="url" value="[website]" onfocus="this.select();" type="text" tabindex="3" size="44" maxlength="133" alt="website" /> … Notice the value="[website]" attribute? It seemed like a good idea at the time — I even threw in a nice […] Continue reading »

Permanently Redirect a Specific IP Request for a Single Page via htaccess

Not the most interesting title, but “oh well”.. Recently, a reader named Alison left a comment requesting help with a particular htaccess trick. She wanted to know how to permanently redirect (301) all requests for a specific page when requested from a specific IP address. In other words, when a visitor coming from 123.456.789 requests the page requested-page.html, the visitor will be redirected to just-for-you.html. All visitors not coming from that specific IP address are not redirected, and thus will […] Continue reading »

CSS Throwdown: Preload Images without JavaScript

[ Preload Images with CSS ]

Clean, easy, effective. You don’t need no stinking JavaScript to preload your images. Nope. Try some tasty CSS and (X)HTML instead! Here’s how to do it with only two easy steps.. Step 1 — Place this in your CSS file: div#preloaded-images { position: absolute; overflow: hidden; left: -9999px; top: -9999px; height: 1px; width: 1px; } Step 2 — Place this at the bottom of your (X)HTML document: <div id="preloaded-images"> <img src="https://perishablepress.com/image-01.png" width="1" height="1" alt="" /> <img src="https://perishablepress.com/image-02.png" width="1" height="1" alt="" […] Continue reading »

Wrapping Your Head around Downlevel Conditional Comments

[ Image: Human Head via Photographic Cubism ]

If you think you understand the logic behind Microsoft’s downlevel conditional comments, you are sadly mistaken. Sure, they seem simple enough on the surface, but as you really try to wrap your head around how and why they work, the subtle complexities of downlevel conditional comments may leave you dazed and confused… In our previous article on Internet Explorer’s exclusive browser-detection method, downlevel conditional comments (DCC), we present an introductory exposition, defining expressions and providing several generalized code examples. Overall, […] Continue reading »

Computer Flashback: Windows 98 Run Commands

[ Image: Screenshot of the MS Run Prompt ]

Even with all the fancy-pants new features found in Windows XP and now Vista, Microsoft Windows 98 (Second Edition) remains our favorite Windows-flavored operating system. We love it so much, we still use it on one of our trusty laptops. Over the years, we have discovered several very useful functions available via the command line or even the “Run” prompt (Start → Run…). Anyway, without spending too much time researching or explaining these wonderful tools, we figured posting the information online may […] Continue reading »

Ultimate htaccess Blacklist

[ Image: Solar Eclipse ]

For those of us running Apache, htaccess rewrite rules provide an excellent way to block spammers, scrapers, and other scumbags easily and effectively. While there are many htaccess tricks involving blocking domains, preventing access, and redirecting traffic, Apache’s mod_rewrite module enables us to target bad agents by testing the user-agent string against a predefined blacklist of unwanted visitors. Any matches are immediately and quietly denied access. Continue reading »

Use PHP to Create Symbolic Links without Shell Access

[ Image: Chain Linkage ]

On Unix systems, a symbolic link refers to a file that points to another file or directory. Symbolic links serve as powerful tools for web designers and developers. Using shell access, creating a symbolic link requires only one line of code: ln -s /home/username/public_html/directory1 /home/username/public_html/directory2 Simple enough. Assuming you have access to the linux shell. Unfortunately, many shared hosting environments deny shell access. Fortunately, creating symbolic links — also called “symlinks” — remains a possibility via the PHP symlink() function. […] Continue reading »

SEO 101: Best Practices

[ Image: Abstracted Documents ]

After studying Peter Kent’s excellent book, Search Engine Optimization for Dummies, several key methods emerged for optimizing websites for the search engines. Although the book is written for people who are new to the world of search engine optimization (SEO), many of the principles presented throughout the book remain important, fundamental practices even for the most advanced SEO-wizards. This article divulges these very useful SEO practices and organizes them into manageable chunks. Continue reading »

Smooth Operators: Sharpen your Google Search Skills

[ Google Search ]

Coming soon to the World Wide Web: Everything. The perpetually evolving sum of human knowledge available online. Anywhere. Anytime. So, what are you looking for? Information concerning something, somewhere, about somebody.. You know it’s there somewhere. Sure, you could waste time by digging through that immense labyrinth of browser bookmarks, maybe eventually finding that one link that may or may not lead you to the page that you remember.. No thanks. The Web is far too rich in information to […] Continue reading »

Go Back via JavaScript and PHP

This quick tutorial explains how to use HTML, JavaScript, and/or PHP to enable visitors to “go back” to the previous page. You can use either method to add a simple “go back” link or form button to your web pages. Continue reading »

Random Fixinz for Hotmail via Outlook Express

Note: The methods described in this tutorial apply to older versions of Internet Explorer (version < 6) and Outlook Express (version < 6), and are provided here for reference and historical purposes only. Continue reading »

Welcome
Perishable Press is operated by Jeff Starr, a professional web developer and book author with two decades of experience. Here you will find posts about web development, WordPress, security, and more »
WP Themes In Depth: Build and sell awesome WordPress themes.
Thoughts
Replacing my elaborate 27in iMac desk setup with a 15in Macbook Air.
Launching my new plugin, Head Meta Pro 🚀 Complete meta tags for WordPress.
Migrating sites to a new server, so far so good. Please report any bugs, thank you.
Arc browser looked good but lost me at “account required”. No browsers do that.
Finishing up the pro version of Head Meta Data plugin, launch planned this month.
Finally finished my ultimate block list to stop AI bots :) Blocks over 400+ AI bots!
After 10 years working late at night, my schedule has changed. I am now a “morning person”, starting my day at 6am or earlier.
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