php验证身份证格式

//验证省份证格式是否正确

    public static function is_idcard($id){

        $id = strtoupper($id);

        $regx = "/(^\d{15}$)|(^\d{17}([0-9]|X)$)/";

        $arr_split = array();

        if(!preg_match($regx, $id)){

            return FALSE;

        }

        if(15==strlen($id)){//检查15位

            $regx = "/^(\d{6})+(\d{2})+(\d{2})+(\d{2})+(\d{3})$/";

            @preg_match($regx, $id, $arr_split);

            //检查生日日期是否正确

            $dtm_birth = "19".$arr_split[2] . '/' . $arr_split[3]. '/' .$arr_split[4];

            if(!strtotime($dtm_birth)) {

                return FALSE;

            }else{

                return TRUE;

            }

        }else{//检查18位

            $regx = "/^(\d{6})+(\d{4})+(\d{2})+(\d{2})+(\d{3})([0-9]|X)$/";

            @preg_match($regx, $id, $arr_split);

            $dtm_birth = $arr_split[2] . '/' . $arr_split[3]. '/' .$arr_split[4];

            if(!strtotime($dtm_birth)){//检查生日日期是否正确

                return FALSE;

            }else{

                //检验18位身份证的校验码是否正确。

                //校验位按照ISO 7064:1983.MOD 11-2的规定生成，X可以认为是数字10。

                $arr_int = array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2);

                $arr_ch = array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2');

                $sign = 0;

                for ( $i = 0; $i < 17; $i++ ) {

                    $b = (int) $id{$i};

                    $w = $arr_int[$i];

                    $sign += $b * $w;

                }

                $n = $sign % 11;

                $val_num = $arr_ch[$n];

                if ($val_num != substr($id,17, 1)) {

                    return FALSE;

                }else{

                    return TRUE;

                }

            }

        }

    }