/* |
* @todo 中文截取,支持gb2312,gbk,utf-8,big5 |
* |
* @param string $str 要截取的字串 |
* @param int $start 截取起始位置 |
* @param int $length 截取长度 |
* @param string $charset utf-8|gb2312|gbk|big5 编码 |
* @param $suffix 是否加尾缀 |
*/ |
function csubstr( $str , $start =0, $length , $charset = "utf-8" , $suffix =true) |
{ |
if (function_exists( "mb_substr" )) |
return mb_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 ; |
} |