用当前日期作为log文件名字

//设置数据生成时间  //需要添加time.htime_t now ;struct tm *tm_now ;time(&now) ;tm_now = localtime(&now) ;char buff[500];sprintf(buff,"data_%d-%d-%d-%d-%d-%dinfo.xls",tm_now->tm_year+1900, tm_now->tm_mon+1, tm_now->tm_mday, tm_now->tm_hour, tm_now->tm_min, tm_now->tm_sec) ;DF.open_xls(buff);//新建文件的类