Бывает, что при переходе на новый домен, хочется сохранить трафик со старого домена и для удобства хочешь, чтобы при переходе на старый домен, пользователя автоматически перенаправляло на новый домен. Это легко сделать, добавив в корень сайта всего два файла.

1. Файл без изменений index.php:

<?php
/*
=====================================================
 DataLife Engine - by SoftNews Media Group
-----------------------------------------------------
 https://dle-news.ru/
-----------------------------------------------------
 Copyright (c) 2004-2023 SoftNews Media Group
=====================================================
 This code is protected by copyright
=====================================================
*/

ob_start();
ob_implicit_flush(false);

error_reporting ( E_ALL ^ E_WARNING ^ E_DEPRECATED ^ E_NOTICE );
ini_set ( 'error_reporting', E_ALL ^ E_WARNING ^ E_DEPRECATED ^ E_NOTICE );

define('DATALIFEENGINE', true);
define('ROOT_DIR', dirname(__FILE__));
define('ENGINE_DIR', ROOT_DIR . '/engine');

require_once(ENGINE_DIR . '/classes/plugins.class.php');
require_once(DLEPlugins::Check(ROOT_DIR . '/engine/init.php'));

2. Файл, вначале заменяем на свои сайты .htaccess:

DirectoryIndex index.php

<IfModule mod_rewrite.c>
	RewriteEngine On
	
RewriteCond %{HTTP_HOST} ^www\.site\.ru$ [NC]

RewriteRule ^(.*)$ http://newsite.ru/$1 [L,R=301]

RewriteCond %{HTTP_HOST} ^site\.ru$ [NC]

RewriteRule ^(.*)$ http://newsite.ru/$1 [L,R=301]

	RewriteRule ^page/([0-9]+)(/?)$ index.php?cstart=$1 [L]

	RewriteRule ^([0-9]{4})/([0-9]{2})/([0-9]{2})/page,([0-9]+),([0-9]+),(.*).html$ index.php?subaction=showfull&year=$1&month=$2&day=$3&news_page=$4&cstart=$5&news_name=$6&seourl=$6 [L]
	RewriteRule ^([0-9]{4})/([0-9]{2})/([0-9]{2})/page,([0-9]+),(.*).html$ index.php?subaction=showfull&year=$1&month=$2&day=$3&news_page=$4&news_name=$5&seourl=$5 [L]
	RewriteRule ^([0-9]{4})/([0-9]{2})/([0-9]{2})/print:page,([0-9]+),(.*).html$ index.php?mod=print&subaction=showfull&year=$1&month=$2&day=$3&news_page=$4&news_name=$5&seourl=$5 [L]
	RewriteRule ^([0-9]{4})/([0-9]{2})/([0-9]{2})/(.*).html$ index.php?subaction=showfull&year=$1&month=$2&day=$3&news_name=$4&seourl=$4 [L]

	RewriteRule ^([^.]+)/page,([0-9]+),([0-9]+),([0-9]+)-(.*).html$ index.php?newsid=$4&news_page=$2&cstart=$3&seourl=$5&seocat=$1 [L]
	RewriteRule ^([^.]+)/page,([0-9]+),([0-9]+)-(.*).html$ index.php?newsid=$3&news_page=$2&seourl=$4&seocat=$1 [L]
	RewriteRule ^([^.]+)/print:page,([0-9]+),([0-9]+)-(.*).html$ index.php?mod=print&news_page=$2&newsid=$3&seourl=$4&seocat=$1 [L]
	RewriteRule ^([^.]+)/([0-9]+)-(.*).html$ index.php?newsid=$2&seourl=$3&seocat=$1 [L]

	RewriteRule ^page,([0-9]+),([0-9]+),([0-9]+)-(.*).html$ index.php?newsid=$3&news_page=$1&cstart=$2&seourl=$4 [L]
	RewriteRule ^page,([0-9]+),([0-9]+)-(.*).html$ index.php?newsid=$2&news_page=$1&seourl=$3 [L]
	RewriteRule ^print:page,([0-9]+),([0-9]+)-(.*).html$ index.php?mod=print&news_page=$1&newsid=$2&seourl=$3 [L]
	RewriteRule ^([0-9]+)-(.*).html$ index.php?newsid=$1&seourl=$2 [L]

	RewriteRule ^([0-9]{4})/([0-9]{2})/([0-9]{2})(/?)+$ index.php?year=$1&month=$2&day=$3 [L]
	RewriteRule ^([0-9]{4})/([0-9]{2})/([0-9]{2})/page/([0-9]+)(/?)+$ index.php?year=$1&month=$2&day=$3&cstart=$4 [L]

	RewriteRule ^([0-9]{4})/([0-9]{2})(/?)+$ index.php?year=$1&month=$2 [L]
	RewriteRule ^([0-9]{4})/([0-9]{2})/page/([0-9]+)(/?)+$ index.php?year=$1&month=$2&cstart=$3 [L]

	RewriteRule ^([0-9]{4})(/?)+$ index.php?year=$1 [L]
	RewriteRule ^([0-9]{4})/page/([0-9]+)(/?)+$ index.php?year=$1&cstart=$2 [L]

	RewriteRule ^tags/([^/]*)(/?)+$ index.php?do=tags&tag=$1 [B,L]
	RewriteRule ^tags/([^/]*)/page/([0-9]+)(/?)+$ index.php?do=tags&tag=$1&cstart=$2 [B,L]

	RewriteRule ^xfsearch/(.*)/page/([0-9]+)(/?)+$ index.php?do=xfsearch&xf=$1&cstart=$2 [B,L]
	RewriteRule ^xfsearch/(.*)/?$ index.php?do=xfsearch&xf=$1 [B,L]

	RewriteRule ^user/([^/]*)/rss.xml$ index.php?mod=rss&subaction=allnews&user=$1 [L]
	RewriteRule ^user/([^/]*)/rssturbo.xml$ index.php?mod=rss&subaction=allnews&rssmode=turbo&user=$1 [L]
	RewriteRule ^user/([^/]*)/rssdzen.xml$ index.php?mod=rss&subaction=allnews&rssmode=dzen&user=$1 [L]
	RewriteRule ^user/([^/]*)(/?)+$ index.php?subaction=userinfo&user=$1 [L]
	RewriteRule ^user/([^/]*)/page/([0-9]+)(/?)+$ index.php?subaction=userinfo&user=$1&cstart=$2 [L]
	RewriteRule ^user/([^/]*)/news(/?)+$ index.php?subaction=allnews&user=$1 [L]
	RewriteRule ^user/([^/]*)/news/page/([0-9]+)(/?)+$ index.php?subaction=allnews&user=$1&cstart=$2 [L]

	RewriteRule ^lastnews(/?)+$ index.php?do=lastnews [L]
	RewriteRule ^lastnews/page/([0-9]+)(/?)+$ index.php?do=lastnews&cstart=$1 [L]

	RewriteRule ^catalog/([^/]*)/rss.xml$ index.php?mod=rss&catalog=$1 [L]
	RewriteRule ^catalog/([^/]*)/rssturbo.xml$ index.php?mod=rss&rssmode=turbo&catalog=$1 [L]
	RewriteRule ^catalog/([^/]*)/rssdzen.xml$ index.php?mod=rss&rssmode=dzen&catalog=$1 [L]
	RewriteRule ^catalog/([^/]*)(/?)+$ index.php?catalog=$1 [L]
	RewriteRule ^catalog/([^/]*)/page/([0-9]+)(/?)+$ index.php?catalog=$1&cstart=$2 [L]

	RewriteRule ^newposts(/?)+$ index.php?subaction=newposts [L]
	RewriteRule ^newposts/page/([0-9]+)(/?)+$ index.php?subaction=newposts&cstart=$1 [L]

	RewriteRule ^favorites(/?)+$ index.php?do=favorites [L]
	RewriteRule ^favorites/page/([0-9]+)(/?)+$ index.php?do=favorites&cstart=$1 [L]

	RewriteRule ^rules.html$ index.php?do=rules [L]
	RewriteRule ^statistics.html$ index.php?do=stats [L]
	RewriteRule ^addnews.html$ index.php?do=addnews [L]
	RewriteRule ^rss.xml$ index.php?mod=rss [L]
	RewriteRule ^rssturbo.xml$ index.php?mod=rss&rssmode=turbo [L]
	RewriteRule ^rssdzen.xml$ index.php?mod=rss&rssmode=dzen [L]
	RewriteRule ^sitemap.xml$ uploads/sitemap.xml [L]
	RewriteRule ^google_news.xml$ uploads/google_news.xml [L]
	RewriteRule ^static_pages.xml$ uploads/static_pages.xml [L]
	RewriteRule ^category_pages.xml$ uploads/category_pages.xml [L]
	RewriteRule ^tags_pages.xml$ uploads/tags_pages.xml [L]
	RewriteRule ^news_pages(\d*?).xml$ uploads/news_pages$1.xml [L]

	RewriteCond %{REQUEST_FILENAME} !-d
	RewriteRule ^([^.]+)/page/([0-9]+)(/?)+$ index.php?do=cat&category=$1&cstart=$2 [L]
	RewriteRule ^([^.]+)/?$ index.php?do=cat&category=$1 [L]

	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteRule ^([^.]+)/rss.xml$ index.php?mod=rss&do=cat&category=$1 [L]
	RewriteRule ^([^.]+)/rssturbo.xml$ index.php?mod=rss&do=cat&rssmode=turbo&category=$1 [L]
	RewriteRule ^([^.]+)/rssdzen.xml$ index.php?mod=rss&do=cat&rssmode=dzen&category=$1 [L]
	RewriteRule ^page,([0-9]+),([^/]+).html$ index.php?do=static&page=$2&news_page=$1&seourl=$2 [L]
	RewriteRule ^print:([^/]+).html$ index.php?mod=print&do=static&page=$1&seourl=$1 [L]

	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteRule ^([^/]+).html$ index.php?do=static&page=$1&seourl=$1 [L]
</IfModule>

Вот и все, теперь сайт будет открываться на новом домене всегда!