mediawiki to dokuwiki url redirector

index.php

<?php
// mediawiki to dokuwiki url redirector
// use .htaccess to rewrite all requests to this file:
// RewriteEngine on
// RewriteCond %{REQUEST_FILENAME} !-f
// RewriteCond %{REQUEST_FILENAME} !-d
// RewriteRule ^(.*)$ /wiki/index.php [NC,L,QSA]

$prefix = '/wiki';

// static replaces
$statics = [
  '/index.php/Main_Page' => '/doku/start',
  '/index.php/SIP/IAX_Configuration_hints' => '/doku/sip_configuration_hints'
];

function doRedirect($redir) {
  $url = "https://eventphone.de".$redir;
  header("HTTP/1.1 301 Moved Permanently");
  header("Location: ".$url);
  header("Connection: close");
  die();
}

$uri = $_SERVER['REQUEST_URI'];

// remove prefix from URI
$req = preg_replace('/^' . preg_quote($prefix, '/') . '/', '', $uri);

// process static replaces first
$redir = strtr($req, $statics);
if ( $redir != $req ) { doRedirect($redir); }

// mediawiki -> dokuwiki url
$redir = strtolower($req);
$redir = str_replace("/index.php/", "", $redir);
$redir = str_replace("/", "_", $redir);
$redir = "/doku/".$redir;

doRedirect($redir);

?>