I am a complete WordPress noob, so please don't mind. I'm working on a project where developers tweaked the core WordPress code. My job is to extract whatever core functions they changed and put them somewhere else so that in the future when the WordPress version is upgraded it will be more maintainable.
I did some research and it looks like writing a plugin is the way to go. After reading this: https://codex.wordpress.org/Writing_a_Plugin , I'm under the assumption that WordPress will first look through all the functions in my plugins and if it finds one it won't default to the WordPress core version of the function? So is this equivalent to overriding the WordPress core functions?
So from the link I provided, it looks like plugins just require: 1. (by default, unless changed) storing them under
wp-content/plugins/my_plugin_name 2. comments in the head of the PHP file stating the plugin details.
So in this case, can I just make a single file
wp-content/plugins/my_plugin_name/my_plugin_name.php with all the customized core functions inside of it? Do I not to add any
include "my_plugin_name" ? It just loads automatically?