PHP, This function removes the accents, white-spaces and symbols from characters in a string. Can be used to clear the strings on usernames, filenames

clear_string.php

/**
 * Function clear_string
 *
 * Function used to user strings as usernames, filenames
 * This function removes the accents, white-spaces and symbols from characters in a string
 */
if (! function_exists('clear_string'))
{
	function clear_string($str = '')
	{
	  $str = strtr(utf8_decode($str), utf8_decode('àáâãäçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ'), 'aaaaaceeeeiiiinooooouuuuyyAAAAACEEEEIIIINOOOOOUUUUY');
          $str = strtolower(trim(preg_replace("![^a-z0-9_]+!i", "", $str)));
	  return $str;
	}
}