The following is a list of resources that I have found helpful and want to keep track of for future reference.
1. Download latest version of WordPress
$ wget https://wordpress.org/latest.zip
2. Unzip archive
$ unzip latest.zip
3. Move files to current directory
$ mv ~/current-directory/wordpress/* ~/current-directory/
4. Remove unneeded files
$ rm -r wordpress
$ rm latest.zip
1. Clear the PHP OPCache
$ php -r "opcache_reset();"
- WordPress search query vars (WordPress Codex)
- How to Add an Advanced Search to Your WordPress Site (SitePoint Article)