WordPress - Enable WP_DEBUG only for specific IP address.

wp-config.php

<?php
/**
 * File: wp-config.php
 * 
 * Enable WordPress debug only for your IP address
 *
 * Once you know your IP address you can edit your wp-config.php file and edit the WP_DEBUG constant and replace it with this function and your IP address.
 * 
 * NOTE: If you re-boot your router and have a dynamic IP address you will need to update your IP address in wp-config.php
 */

// 1. by REMOTE_ADDR (recommended)
if ( !empty($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] == '00.00.00.00' ) {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', true );
	define( 'WP_DEBUG', true );
	define( 'WP_DEBUG_LOG', true );
	define( 'WP_DEBUG_DISPLAY', true );
} else {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', false );
	define( 'WP_DEBUG', false );
	define( 'WP_DEBUG_LOG', false );
	define( 'WP_DEBUG_DISPLAY', false );
}

// 2. by HTTP_X_REAL_IP
if ( !empty($_SERVER['HTTP_X_REAL_IP']) && $_SERVER['HTTP_X_REAL_IP'] == '00.00.00.00' ) {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', true );
	define( 'WP_DEBUG', true );
	define( 'WP_DEBUG_LOG', true );
	define( 'WP_DEBUG_DISPLAY', true );
} else {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', false );
	define( 'WP_DEBUG', false );
	define( 'WP_DEBUG_LOG', false );
	define( 'WP_DEBUG_DISPLAY', false );
}

// 3. by HTTP_CLIENT_IP
if ( !empty($_SERVER['HTTP_CLIENT_IP']) && $_SERVER['HTTP_CLIENT_IP'] == '00.00.00.00' ) {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', true );
	define( 'WP_DEBUG', true );
	define( 'WP_DEBUG_LOG', true );
	define( 'WP_DEBUG_DISPLAY', true );
} else {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', false );
	define( 'WP_DEBUG', false );
	define( 'WP_DEBUG_LOG', false );
	define( 'WP_DEBUG_DISPLAY', false );
}

// 4. by HTTP_X_FORWARDED_FOR
if ( !empty($_SERVER['HTTP_X_FORWARDED_FOR']) && $_SERVER['HTTP_X_FORWARDED_FOR'] == '00.00.00.00' ) {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', true );
	define( 'WP_DEBUG', true );
	define( 'WP_DEBUG_LOG', true );
	define( 'WP_DEBUG_DISPLAY', true );
} else {
	define( 'WP_DISABLE_FATAL_ERROR_HANDLER', false );
	define( 'WP_DEBUG', false );
	define( 'WP_DEBUG_LOG', false );
	define( 'WP_DEBUG_DISPLAY', false );
}