PHP Archives - Page 2 of 4

Optimize WordPress MySQL tables through Cron, behind the scenes

To regularly optimize my WordPress database tables, I created a small plugin that utilizes the WordPress Cron feature. This comes in handy to perform database optimization for WordPress on a regular basis, without forgetting about it. Just activate and enjoy. And here is the plugin code.

By Jan Reilink 04/03/2016WordPress

Web application security

Cracking PHP rand()

Webapps occasionaly need to create tokens that are hard to guess. For example for session tokens or CSRF tokens, or in forgot password functionality where you get a token mailed to reset your password. These tokens should be cryptographically secure, but are often made by calling rand() multiple times and transforming the output to a string. This post will explore how hard it is to predict a token made with rand().

By Jan Reilink 15/02/2016Web application security

WordPress

Minify WP-Super-Cache HTML cache files: WPSCMin a WP-Super-Cache plugin

The WordPress WP-Super-Cache cache plugin doesn't minify HTML cache files, which I find a disadvantage. Knowing minify libraries, I went looking for an existing solution (why reinvent the wheel?), and found one: WPSCMin. Read on ...

By Jan Reilink 27/12/2015WordPress

GNU Linux

Generate pseudo-random passwords with OpenSSL

Use OpenSSL to generate pseudo-random strings to be used as passwords. Passwords for users, system accounts and service accounts. I provide you examples for Linux (Bash), Windows and PHP.

By Jan Reilink 27/11/2015GNU Linux

Code base

Always_populate_raw_post_data setting in PHP 5.6 & Magento 2.0

As of PHP 5.6.0 always_populate_raw_post_data is deprecated and is commented out. So this value always equals 0 in php.ini. Here is how to fix upgrades to Magento 2.0 in PHP 5.6 and higher: PHP 7+.

By Jan Reilink 25/11/2015Code base

Windows Server

Optimize PHP’s OPcache configuration

Learn how to optimize PHP's OPcache configuration and make OPcache perform even better! After you've configured and optimized PHP realpath_cache_size, it is time to fine-tune the OPcache cache mechanism. With just a few tweaks you can tune OPcache to make it perform much better, and here is how!

By Jan Reilink 31/07/2015Windows Server

WordPress

How to add conditional analytics tracking code in WordPress Multisite

In my WordPress multisite, I use one theme for three sites and a tracking code for analytics on my websites. Whether it is Google Analytics or Piwik doesn't matter. Here is how you can conditionally add tracking codes to your WordPress Multisite: Use a condition in functions.php to add the tracking code for Piwik/Matomo Analytics or Google Analytics.

By Jan Reilink 11/07/2015WordPress

Web application security

Add a delay to your WordPress login form

This plugin adds a three second delay when logging into WordPress. This slows down brute-force attacks on your website. However, it is not recommended to use sleep(), because a heavy brute-force attack will let all those POST requests sleep for the given amount of time.

By Jan Reilink 10/07/2015Web application security

Web applications

PHP 5.6 default_charset change may break HTML output

An important note for everyone who's upgrading from PHP 5.4 and PHP 5.5 to PHP 5.6: the PHP default_charset in php.ini changed from "empty" to UTF-8, often breaking sites after upgradiong from PHP 5.4 and PHP 5.5 to PHP 5.6. UTF-8 encoding breaks when upgrading PHP 5.6 to PHP 7.0.

By Jan Reilink 31/03/2015Web applications

Code base

Convert PHP ext/mysql to MySQLi

Learn how to convert PHP mysql functions to PHP MySQLi extension. The old ext/mysql extension is deprecated as of PHP 5.5.0 and therefore it's a must to migrate away from using it and towards MySQLi or PHP Data Object (PDO). This post will show you how.

By Jan Reilink 04/02/2015Code base

get current PHP realpath_cache_size value

Code base

How to set a good PHP realpath_cache_size

Learn how to set a good PHP realpath_cache_size and optimize your PHP performance. . Increasing realpath_cache_size might greatly improve PHP performance, as PHP states: "this value should be increased on systems where PHP opens many files." Setting a correct value for PHP realpath_cache_size can greatly improve PHP performance and optimize WordPress - and other CMS's - websites.

By Jan Reilink 23/10/2014Code base

Code base

Redirect old URL to new URL or send 404 page with PHP

Use a PHP redirect script to redirect old PHP URLs to new ones. This examples uses a 301 Moved Permanently redirect, perfect for SEO.

By Jan Reilink 12/10/2014Code base

WordPress

Display commas in WordPress tags

Sometimes you may want to display commas in tag names. For example if you have a business directory listing and want to create one single taxonomy (tag name) "cafe, restaurant, bar". This post shows you how to create a filter in your functions.php file to display WordPress tags with a comma, enjoy!

By Jan Reilink 12/10/2014WordPress

Code base

Check website availability with PHP and cURL

Perform a PHP cURL request to check if your website is up or not. Verify your website's online status and availability using just PHP.

By Jan Reilink 10/09/2014Code base

Web application security

Exploit PHP mail() to get remote code execution

If you are able to control the 5th parameter of PHP mail() function ($options), you have the opportunity to execute arbitrary commands. Remote Code Execution (RCE) in PHP mail()

By Jan Reilink 07/09/2014Web application security

PowerShell