支持中文和其他编码的php截取字符串函数分享(截取中文字符串)

/**
* 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,$start,$charset);
elseif(function_exists('iconv_substr')) {
$slice = iconv_substr($str,$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],$length));
}
return $suffix ? $slice.'...' : $slice;
}