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Web Dev + WordPress + Security

PHP Code Not Displayed in Browser

[ Screenshot showing proper display of PHP code snippet ]

Recently a reader sent in a bug report about this post on bbPress. For some reason the PHP code snippets were not displaying properly in the browser. Basically, instead of looking neat and tidy as always, the code looked like a garbled mess of spaced-out nonsense. And by “spaced out” I don’t mean in a good way: there was literally like 100px of vertical space breaking up the jumbled lines of code. It was definitely a mess, so I began […] Continue reading »

How to Modify HTTP Headers in the WordPress Admin Area

WordPress provides the wp_headers filter hook and send_headers action hook to add and modify HTTP requests. For front-end pages, these are ideal hooks that should be used whenever possible. Unfortunately however neither hook works on all pages in the WordPress Admin Area. After some experimentation, I found an easy solution to modify HTTP headers on any/all pages in the Admin Area. Continue reading »

WordPress Error Fix: “Call to undefined function get_header()”

[ Call to undefined function ]

I’m seeing a big increase in bot attacks targeting theme files directly. First they get the URL to your theme directory. There are numerous ways for a bot to get this information. For example most themes include assets like CSS and JavaScript files, and the link includes the full URL. So then once they have the theme URL, bad bots will make direct requests for well-known theme template files, like index.php and header.php. Requesting template files directly may reveal possible […] Continue reading »

X Theme Leftover Code Snippets

While working on the site’s 24th redesign, I ended up with about 10 code snippets that were awesome but ultimately not needed. So rather than just delete these tasty functions, I am posting them here for future reference. Who knows, during the next site update I may decide to implement or repurpose some of these techniques. And of course sharing is caring, so feel free to use any of these code snippets in your own projects. Check out the Table […] Continue reading »

Get Random with PHP

This tutorial explains numerous ways to get random items via PHP: numbers, strings, passwords, nonces, images, and more. I use these techniques in various projects, and want to round them all up in one place for easy reference. I’ll be updating this post with additional techniques as I get them. Continue reading »

Stop User Enumeration in WordPress

[User Enumeration ]

This tutorial explains how to block user-enumeration scans in WordPress. As explained in greater depth here, user enumeration happens when some malicious script scans a WordPress site for user data by requesting numerical user IDs. For example, requests for author=1 through some number, say, author=1000, may reveal the usernames for all associated users. With a simple enumeration script, an attacker can scan your site and obtain a list of login names in a matter of seconds. Continue reading »

Huge Collection of Code Snippets: HTAccess, PHP, WordPress, jQuery, HTML, CSS

[ WP Cron HTTP Auth ]

Please excuse this self-serving, miscellaneous post, but I’ve just got to purge all of these code snippets and scraps collected over the years. Whenever I update this site, I place any removed/unused code snippets into a giant note file for future reference, just in case. There’s all sorts of different types of code and snippets that just keep growing and growing and.. and finally it gets to a point where I just need to dump everything and start fresh. Welcome […] Continue reading »

Upload Large Files or Die Trying

[ Screenshot: Editable and non-editable file permissions in Plesk ]

I recently spent some time wrestling with various e-commerce/shopping-cart/membership plugins. One of them was of course the popular WP e-Commerce plugin, which uses a directory named “downloadables” to store your precious goods. I had some large files that needed to go into this folder, but the server’s upload limit stopped me from using the plugin’s built-in file uploader to do so. Continue reading »

PHP Tip: Encode & Decode Data URLs

[ RSS Feed Icon ]

Converting small images to data-URLs is a great way to eliminate HTTP requests and decrease loading time for your pages. Using PHP‘s base64_encode() and base64_decode() functions, we have the power to convert images to data-URLs and vice-versa. This article explains how it all works, and shows some different ways of converting back and forth between original and encoded images. Continue reading »

Is it Secret? Is it Safe?

[ Enjoying the Evening ]

Whenever I find myself working with PHP or messing around with server settings, I nearly always create a phpinfo.php file and place it in the root directory of whatever domain I happen to be working on. These types of informational files employ PHP’s handy phpinfo() function to display a concise summary of all of your server’s variables, which may then be referenced for debugging purposes, bragging rights, and so on. While this sort of thing is normally okay, I frequently […] Continue reading »

Stupid WordPress Tricks

[ WordPress ]

One of the most popular articles here at Perishable Press is my January 2005 post, Stupid htaccess Tricks. In that article, I bring together an extensive collection of awesome copy-&-paste HTAccess code snippets. Four years later, people continue to tell me how much they enjoy and use the content as a bookmarked reference for many of their HTAccess needs. The article was even published in a book on Joomla! Security. This is very inspiring to me, so I have decided […] Continue reading »

Pimp Your 404: Presentation and Functionality

[ Screenshot: Default Apache 404 Error Page ]

I have been wanting to write about 404 error pages for quite awhile now. They have always been very important to me, with customized error pages playing a integral part of every well-rounded web-design strategy. Rather than try to re-invent the wheel with this, I think I will just go through and discuss some thoughts about 404 error pages, share some useful code snippets, and highlight some suggested resources along the way. In a sense, this post is nothing more […] Continue reading »

Block Multiple IP Addresses with PHP

[ Screenshot: The Legion of Doom ]

Let’s face it. There’s just as much scum on the Internet as there is out there in the “real world.” Maybe even more, who knows. From scammers and spammers to scrapers and crackers, the Web is just crawling with all sorts of pathetic scumbags. As predictably random as much of the malicious activity happens to be, it is virtually guaranteed that you will be hounded by at least a few persistent IP addresses that, for whatever reason, have latched on […] Continue reading »

9 Ways to Set Dynamic Body IDs via PHP and WordPress

When designing sites, it is often useful to identify different pages by adding an ID attribute to the <body></body> element. Commonly, the name of the page is used as the attribute value, for example: <body id=”about”></body> In this case, “about” would be the body ID for the “About” page, which would be named something like “about.php”. Likewise, other pages would have unique IDs as well, for example: <body id=”archive”> </body><body id=”contact”> </body><body id=”subscribe”> </body><body id=”portfolio”></body> ..again, with each ID associated […] Continue reading »

WordPress Tip: Valid, SEO-Friendly Email Permalink Buttons

Amazing but true..

In addition to your choice collection of “Share This” links, you may also want to provide visitors with a link that enables them to quickly and easily send the URL permalink of any post to their friends via email. This is a great way to increase your readership and further your influence. Just copy & paste the following code into the desired location in your page template: <a href=”mailto:?subject=Fresh%20Linkage%20@%20Perishable%20Press&amp;body=Check%20out%20<?php the_permalink(); ?>%20from%20Perishable%20Press” title=”Send a link to this post via email” rel=”nofollow”>Share […] Continue reading »

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

[ Image: Abstract Mathematical Diagram ]

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 […] 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 »
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Thoughts
Air finally clearing here in WA. Feeling grateful to breathe again. #oxygenmatters
Past week here in WA state has been hellish. So much smoke, like living in a chimney.
Now in September, I’m where I wanted to be in March.
Spent some time updating my article on unsafe characters, once again current with latest IETF specification.
Just realized that “Neo” is an anagram for “One”. As in, “he is the One” (The Matrix).
To get VLC app to load all songs (including subfolders), go to Preferences ▸ Show All ▸ Playlist ▸ Subdirectory behavior ▸ Expand.
Switching from PhotoShop to Affinity Photo is one of the most liberating work-related things I've done in 20 years.
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