字符截取函数：
<?php
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);
}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。
原文：http://7300272.blog.51cto.com/7290272/1948702