在TP3.2中封装字符串截取的方法

在TP3.2中封装字符串截取的方法

/** * 字符串截取，支持中文和其他编码 * @static * @access public * @param string $str 需要转换的字符串 * @param string $start 开始位置 * @param string $length 截取长度 * @param string $charset 编码格式 * @param string $suffix 截断显示字符 * @return string */function msubstr($str, $start = 0, $length, $charset = "utf-8", $suffix = true){    if (function_exists("mb_substr"))        $slice = mb_substr($str, $start, $length, $charset);    elseif (function_exists('iconv_substr')) {        $slice = iconv_substr($str, $start, $length, $charset);        if (false === $slice) {            $slice = '';        }    } else {        $re['utf-8'] = "/[\x01-\x7f]|[\xc2-\xdf][\x80-\xbf]|[\xe0-\xef][\x80-\xbf]{2}|[\xf0-\xff][\x80-\xbf]{3}/";        $re['gb2312'] = "/[\x01-\x7f]|[\xb0-\xf7][\xa0-\xfe]/";        $re['gbk'] = "/[\x01-\x7f]|[\x81-\xfe][\x40-\xfe]/";        $re['big5'] = "/[\x01-\x7f]|[\x81-\xfe]([\x40-\x7e]|\xa1-\xfe])/";        preg_match_all($re[$charset], $str, $match);        $slice = join("", array_slice($match[0], $start, $length));    }    //字数不满不添加...    $count = mb_strlen($str, 'utf-8');    if ($count > $length) {        return $suffix ? $slice . '...' : $slice;    } else {        return $slice;    }}