<?php

/**
* @version $Id: strcspn.php,v 1.1 2006/02/25 13:50:17 harryf Exp $
* @package utf8
* @subpackage strings
*/

/**
* UTF-8 aware alternative to strcspn
* Find length of initial segment not matching mask
* Note: requires utf8_strlen and utf8_substr (if start, length are used)
* @param string
* @return int
* @see http://www.php.net/strcspn
* @see utf8_strlen
* @package utf8
* @subpackage strings
*/
function utf8_strcspn($str, $mask, $start=null, $length=null)
{
	if (empty($mask) || strlen($mask) == 0)
		return null;

	$mask = preg_replace('!([\\\\\\-\\]\\[/^])!','\\\${1}', $mask);

	if (!is_null($start) || !is_null($length))
		$str = utf8_substr($str, $start, $length);

	preg_match('/^[^'.$mask.']+/u', $str, $matches);

	if (isset($matches[0]))
		return utf8_strlen($matches[0]);

	return 0;
}