One of the check types included in wp doctor is File_Contents, or the ability to check all or a selection of WordPress files for a given regex pattern. The check type is in use by a couple of the default diagnostic checks, and you can use the File_Contents check type in your custom doctor.yml configuration file.
The File_Contents check type is the most efficient way to check WordPress files because it only iterates the filesystem once, regardless of how many file checks you've registered.
As an example, here are two checks using File_Contents, one which ensures sessions aren't used by plugins and the other which ensures $_SERVER['SERVER_NAME'] isn't used in wp-config.php:
file-sessions:
check: File_Contents
options:
regex: .*(session_start|\$_SESSION).*
only_wp_content: true
file-server-name-wp-config:
check: File_Contents
options:
regex: define\(.+WP_(HOME|SITEURL).+\$_SERVER.+SERVER_NAME
path: wp-config.php
Run together, you might see:
$ wp doctor check --config=file-contents.yml --all
+----------------------------+---------+-----------------------------------------------------------------------------------------+
| name | status | message |
+----------------------------+---------+-----------------------------------------------------------------------------------------+
| file-sessions | success | All 'php' files passed check for '.*(session_start|\$_SESSION).*'. |
| file-server-name-wp-config | success | All 'php' files passed check for 'define\(.+WP_(HOME|SITEURL).+\$_SERVER.+SERVER_NAME'. |
+----------------------------+---------+-----------------------------------------------------------------------------------------+
The File_Contents check type accepts the following options:
- 'regex': Regex pattern to check against each file's contents.
- 'extension'. File extension to check. Defaults to 'php'. Separate multiple file extensions with a '|'.
- 'path'. Check a specific file path. Value should be relative to
ABSPATH(e.g. 'wp-content' or 'wp-config.php'). - 'only_wp_content': Only check the wp-content directory.