transliteraturl.php

<?php 
/*
Plugin Name: Transliteration URL
Plugin URI: https://gist.github.com/mrzlodey/d7165cd4f054a5763946
Description: Convert cyrillic characters in WordPress permalinks and loaded files to latin characters.
Author: SK
Version: 1.0.0
Author URI: http://codebeer.ru/
*/
function transliterate_url( $text ) {
	$text = mb_strtolower( $text, 'UTF-8' );
	$symbol_table = array('а' => 'a',	'б' => 'b',	'в' => 'v',
			      'г' => 'g',	'д' => 'd',	'е' => 'e',
			      'ё' => 'yo',	'ж' => 'zh',	'з' => 'z',
			      'и' => 'i',	'й' => 'j',	'к' => 'k',
			      'л' => 'l',	'м' => 'm',	'н' => 'n',
			      'о' => 'o',	'п' => 'p',	'р' => 'r',
			      'с' => 's',	'т' => 't',	'у' => 'u',
			      'ф' => 'f',	'х' => 'h',	'ц' => 'c',
			      'ч' => 'ch',	'ш' => 'sh',	'щ' => 'shh',
			      'ъ' => "",	'ы' => 'y',	'ь' => "",
			      'э' => 'e',	'ю' => 'yu',	'я' => 'ya');
	$text = strtr( $text, $symbol_table );
	return $text;
}
add_filter( 'sanitize_title', 'transliterate_url', 1 );
add_filter( 'sanitize_file_name', 'transliterate_url', 1 );
?>