Is it possible to override the ABSPATH constant

The official reply is that ABSPATH is more for backward compatibility with code which was written when plugins were including wp-config.php and overriding WP_CONTENT_DIR should be enough. https://core.trac.wordpress.org/ticket/29626#comment:3 https://core.trac.wordpress.org/ticket/26592#comment:8

Multiple wp-config.php files in one home directory

Use one main wp-config.php and name the others according to the name of the host: example.com.config.php example.net.config.php and so on. In your main wp-config.php write: $current_config = __DIR__ . “https://wordpress.stackexchange.com/” . $_SERVER[‘HTTP_HOST’] . ‘.config.php’; if ( file_exists( $current_config ) ) require_once $current_config;

How to reliably set file/folder permissions?

FS_CHMOD_FILE and FS_CHMOD_DIR are applicable only if both of the following criteria are satisfied … the host allows the change in permissions (for an explanation on this, please see https://superuser.com/a/767261 ) the files are created by WordPress (such as WordPress core updates / upgrades, plugin installations / updates, theme installations / updates, or user uploaded … Read more

What Does this Code Snippet Do?

The first part (add_filter()) tells WordPress to use the direct-write method. The second part (define()) tells WordPress to apply 0751 permissions to any directory it creates. More information here. I would not consider using the Direct Write method to be safe to use in a live, public, shared-hosting environment. Also, it might not – and … Read more

Creating the wp-config.php file manually

Here is how you make your config.php manually: In your download there should be a wp-config-sample.php. Open this is a text editor. Fill in your database connection details. Go to https://api.wordpress.org/secret-key/1.1/salt/ and get the code. Copy the above cope and paste into the sample file over the top of the existing defines Save the file … Read more