voku / portable-utf8

   *

   * @return   string The string with unwanted characters stripped from the left

   */

  public static function ltrim($str = '', $chars = INF)

  {

    $str = (string)$str;

    if (!isset($str[0])) {

      return '';

    }

    $chars = INF === $chars ? '\s' : self::rxClass($chars);

    return preg_replace("/^{$chars}+/u", '', $str);

  }

  /**

   * Returns the UTF-8 character with the maximum code point in the given data.

   *

   * @return   string The string with unwanted characters stripped from the right

   */

  public static function rtrim($str = '', $chars = INF)

  {

    $str = (string)$str;

    if (!isset($str[0])) {

      return '';

    }

    $chars = INF === $chars ? '\s' : self::rxClass($chars);

    return preg_replace("/{$chars}+$/u", '', $str);

  }

  /**

   * rxClass