golang log类记录日志和输出

osFile, err := os.OpenFile("log.txt", os.O_WRONLY|os.O_CREATE, 0755)
    if err != nil {
        log.Fatalf("create file log.txt failed: %v", err)
    }

    logger := log.New(io.MultiWriter( os.Stdout, osFile), "", log.Lshortfile|log.LstdFlags)
    logger.Printf("hello")

参考文章：

https://zhuanlan.zhihu.com/p/393292157