rel="nofollow" href="http://wordpress.org/latest.zip">http://wordpress.org/latest.zip
● http://wordpress.org/latest.tar.gz
These download links never change. Each new version of WordPress is automatically compressed and saved at this location when the version is tagged. When you save the archive to your computer, you should rename the file to include the WordPress version number, such as wordpress-4.1.zip. This will help you remember what version of WordPress you saved to your computer.
WordPress.org features a release archive for WordPress. The Release Archive features a list of downloadable archives for every release of WordPress since version 0.71. The archive is located at http://wordpress.org/download/release-archive/.
Remember that only the most current version of WordPress is actively maintained so these downloads are more for reference than actual use. “Actively maintained” means that critical fixes for security, performance, or reliability problems are made to the active branch and not applied retroactively to previous releases. If you need the fix, you’ll need to upgrade your installed version of WordPress.
Another great use for these older versions of WordPress is to roll a website back to a previous version. For example, if you update a very old version of WordPress to the latest stable version and run into problems, you could easily download the old version that the website was originally running to revert to. The Release Archive also features a download for every beta and release candidate version of WordPress as well. This is great to see the overall growth of WordPress as a software platform.
The release archives are also useful if you need to update an old version of WordPress that has hacks made to the core. Simply compare the website’s WordPress source code with the same version of WordPress from the release archive and any differences, or core hacks, will be discovered.
DIRECTORY AND FILE STRUCTURE
The WordPress source code features many different PHP, JavaScript, and CSS code files. Each file serves a specific purpose in WordPress. The beauty of open source software is that all code is publicly available, which means you can easily explore the code to better understand how WordPress functions. The best resource for learning WordPress is the WordPress software itself.
After extracting the WordPress download, you will notice the set file structure for WordPress, as shown in Figure 2.1.
Figure 2.1 Default WordPress file and folder structure
WordPress comes with three directories by default: wp-admin, wp-content, and wp-includes. Core files are all files in the wp-admin and wp-includes directories and the majority of the files in the root WordPress directory. The wp-content directory holds all of your custom files, including themes, plugins, and media. This directory contains the code that controls content manipulation and presentation in WordPress. WordPress HTML content, such as pages and posts, is stored in the MySQL database along with metadata such as tag and category structures, both of which are covered in detail in Chapter 6.
Modifying any of the core WordPress files can result in an unstable website. An innocuous but badly executed change to the Dashboard or login functions, for example, will leave you with a WordPress installation that can’t be managed. Core changes also make it very difficult to update WordPress because all changes made are overwritten when the updated version of WordPress is installed. As discussed in the previous section, critical fixes to the WordPress core are only made in the current branch, so if you are forced to update WordPress to pick up a security fix, you’re going to have to re-integrate any core changes you’ve made and hope they don’t conflict with the changes you want. Maintaining the integrity and stability of your WordPress installation over time is much simpler when you’re not changing files in the core.
In general, the wp-admin, wp-includes, and root directory core WordPress files should never be edited, but the next section covers some core root directory files that can be modified as part of advanced configuration. In general, however, follow this rule that is revisited in Chapter 4: Don’t hack the core!
WORDPRESS CONFIGURATION
WordPress features specific files that can be edited for different purposes. These files can alter how WordPress functions. Always test changes in a development environment before publishing to a production server.
This section covers database connections, storing FTP info, enabling debugging tools, and more using wp-config.php. It also covers the power of the .htaccess file, including increasing PHP memory limits and max upload sizes, creating redirects, and setting access restrictions.
The most important file in any WordPress installation is the wp-config.php file. This file contains all database connection settings, including the database name, username, and password, to access your MySQL database. This file also stores additional database and other advanced WordPress settings. The wp-config.php file was originally named wp-config-sample.php. Renaming the file to wp-config.php is one of the first steps to installing WordPress.
The wp-config.php file is typically stored in the root directory of WordPress. Alternatively, you can move the wp-config.php file out of the WordPress root directory and into the parent directory. So if your WordPress directory is located here:
you can safely move the file to here:
WordPress looks for the wp-config.php file in the root directory first, and if it can’t find that file it looks in the parent directory. This happens automatically so no settings need to be changed for this to work.
NOTE Moving the wp-config.php out of the root WordPress directory is a good security measure, making it nearly impossible to potentially access this file from a web browser.
Some options in WordPress are stored as constants and these can be seen in the wp-config.php file. The constants all have the same format:
OPTION_NAME is the name of the option constant being set; value is the option value and can be updated to whatever setting you would like to save for that option. When adding new options to the wp-config.php file, it’s important the options are added above the line that reads:
If your WordPress installation is having problems connecting to your database, this is the first place to start troubleshooting. If you receive the error message “Error establishing a database connection,” the first thing to do is verify that the DB_NAME, DB_USER, and DB_PASSWORD options are correctly set for your database server. Also verify that the DB_HOST name is set to the correct host for your server. Typically, this is set to localhost, but some hosting companies configure WordPress packages with web servers and MySQL servers on different machines, necessitating a host company–specific configuration option to locate the MySQL database. Contact your hosting tech support or consult their online documentation for the correct host value to set here.
You can change the database character set (charset) by changing the DB_CHARSET option value. By default, this is set to utf8 (Unicode UTF-8), which supports any language, and is almost always the best option.
Since WordPress 2.2, the
