Record yourself reading the process of wordpress. Going to go through it first.
The wordpress version I downloaded is 4.9.5.
The first is the entry file index.php
Just tell to use the theme, then load the wordpress environment and templates.
Enter the wp-blog-header.php file to see
Use a singleton to execute the content in if. It mainly includes 3 parts.
1. Load wp-load.php //Load the libraries required by wordpress
2. wp(); //Set the wordpress query, here is the main execution part of wordpress.
3. Load template-loader.php // theme template
wp-load.php is a bootstrap file that sets absolute path constants and loads the wp-config.php file, which mainly sets data such as database user passwords. Set error output, etc. wordpress environment settings. There is also a judgment to prevent nested installations.
wp-config.php sets the database information, debug mode, and loads wp-settings.php.
wp-settings.php fixes common variables and includes wordpress programs and function libraries
Mainly introduced in wp-includes
load.php //wordpress's own function class library
default-constants.php //define constants and global variables
plugin.php //Load some APIs of the plugin
Load version.php //mainly the required db, php, wordpress version support information
Then execute wp_initial_constants(); as the name implies, it is to be initialized. Set the runtime memory of wordpress. Define many constants.
wp_check_php_mysql_versions(); //Check whether the mysql version of wordpress is supported
Disable magic boot, define time zone, turn off register_globals to prevent user fields from being registered as globals
wp_fix_server_vars(); //Standardize $_SERVER variable
wp_favicon_request(); //Check the request, if it is a request for favicon.ico, you don't need to load all wordpress
The function of the header here is not very clear, mark it, and find the relevant answer tomorrow.