ThinkPHP有一个内置字符截取函数msubstr()如下：
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 $suffix=true：
是否在截取后的字符后面显示省略号，默认true显示，false为不显示
在function.php定义msubstr函数
function msubstr($str, $start=0, $length, $charset="utf-8", $suffix=true){
if(function_exists("mb_substr")){
if($suffix){
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."...";
}else{
return $slice;
}
}