thinkphp截取部分字符串函数

1.函数解释：

msubstr($str,$start=0,$length,$charset=”utf-8″, $suffix=true)
$str:要截取的字符串
$start=0：开始位置，默认从0开始
$length：截取长度
$charset=”utf-8″：字符编码，默认UTF－8
$suffix=true：是否在截取后的字符后面显示省略号，默认true显示，false为不显示
模版使用：{$vo.title|msubstr=0,5,'utf-8',false}

2.使用方法：
在公共方法文件(common.php)中添加以下函数:


function msubstr($str, $start=0, $length, $charset="utf-8", $suffix=true)
{
if(function_exists("mb_substr")){
if($suffix)
return mb_substr($str, $start, $length, $charset)."...";
else
return mb_substr($str, $start, $length, $charset);
}
elseif(function_exists('iconv_substr')) {
if($suffix)
return iconv_substr($str,$start,$length,$charset)."...";
else
return iconv_substr($str,$start,$length,$charset);
}
$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, $length));
if($suffix) return $slice."…";
return $slice;
}