Go语言编程入门超级指南

/**
 * I'm waiting all goroutines on wg done
 * I'm done=[0]
 * I'm done=[1]
 * I'm done=[2]
 * I'm done=[3]
 * I'm done=[4]
 * I'm done=[5]
 * I'm done=[6]
 * I'm done=[7]
 * I'm done=[8]
 * I'm done=[9]
 */
func main() {
    var wg sync.WaitGroup
    for i := 0; i < 10; i++ {
        wg.Add(1)
        go func(id int) {
            defer wg.Done()
            fmt.Printf("I'm done=[%d]n", id)
        }(i)
    }

    fmt.Println("I'm waiting all goroutines on wg done")
    wg.Wait()
}

4.6 网络编程

Golang的net包的抽象层次还是挺高的，用不了几行代码就能实现一个简单的TCP或HTTP服务端了。

4.6.1 Socket编程

package main

import (
    "net"
    "fmt"
    "io"
)

/**
 * Starting the server
 * Accept the connection:  127.0.0.1:14071
 * Warning: End of data EOF
 */
func main() {
    listener, err := net.Listen("tcp", "127.0.0.1:12345")
    if err != nil {
        panic("error listen: " + err.Error())
    }
    fmt.Println("Starting the server")

    for {
        conn, err := listener.Accept()
        if err != nil {
            panic("error accept: " + err.Error())      
        }
        fmt.Println("Accept the connection: ", conn.RemoteAddr())
        go echoServer(conn)
    }
}

func echoServer(conn net.Conn) {
    buf := make([]byte, 1024)
    defer conn.Close()

    for {
        n, err := conn.Read(buf)
        switch err {
            case nil:
                conn.Write(buf[0:n])
            case io.EOF:
                fmt.Printf("Warning: End of data %sn", err)