Clean URL

clean.php

function cleanURL($string)
{
    $url = str_replace("'", '', $string);
    $url = str_replace('%20', ' ', $url);
    $url = preg_replace('~[^\\pL0-9_]+~u', '-', $url); // substitutes anything but letters, numbers and '_' with separator
    $url = trim($url, "-");
    $url = iconv("utf-8", "us-ascii//TRANSLIT", $url);  // you may opt for your own custom character map for encoding.
    $url = strtolower($url);
    $url = preg_replace('~[^-a-z0-9_]+~', '', $url); // keep only letters, numbers, '_' and separator
    return $url;
}