字符截取函数：

<?phpfunctionmsubstr($str,$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,$charset);}else{$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,$length));}$fix='';if(strlen($slice)<strlen($str)){$fix='...';}return$suffix?$slice.$fix:$slice;}?>

此外php函数mb_substr();也可以截取字符。