<pre style="margin-top: 0px; margin-bottom: 0px;"><span style=" color:#0000ff;">package</span><span style=" color:#f57900;"> </span>main

import (

    "fmt"

    "net"

    "time"

)

func main() {

    udpaddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:1789")

    if err != nil {

        fmt.Println(err)

        return

    }

    lis, err := net.ListenUDP("udp", udpaddr)

    if err != nil {

        fmt.Println(err)

        return

    }

    defer lis.Close()

    for {

        buf := make([]byte, 512)

        n, addr, err := lis.ReadFromUDP(buf)

        if err != nil {

            fmt.Println(err)

            continue

        }

        str := string(buf[:n])

        go func(lis *net.UDPConn, addr *net.UDPAddr, body string) {

            lis.WriteToUDP([]byte(body), addr)

            time.Sleep(3e9)

        }(lis, addr, str)

    }

}

package main

import (

	"bytes"

	"encoding/json"

	"fmt"

	"io"

	"net"

	"os"

)

type Fileinfo struct {

	Name string

	Path string

}

func server() {

	laddr := &net.UDPAddr{IP: []byte{127, 0, 0, 1}, Port: 1789}

	con, err := net.ListenUDP("udp", laddr)

	if err != nil {

		fmt.Println(err)

		return

	}

	defer con.Close()

	for {

		Buf := make([]byte, 1024)

		n, raddr, _ := con.ReadFromUDP(Buf)

		var info Fileinfo

		json.Unmarshal(Buf[:n], &info)

		if info.Name != "" {

			if info.Path != "" {

				e := os.Chdir(info.Path)

				if e != nil {

					con.WriteTo([]byte(e.Error()), raddr)

					continue

				}

			}

			con.WriteToUDP([]byte("OK"), raddr)

			File, _ := os.Create(info.Name)

			defer File.Close()

			for {

				Buf := make([]byte, 4096)

				n, r, _ := con.ReadFromUDP(Buf)

				if r.String() != raddr.String() {

					continue

				}

				if n == 4 && bytes.Contains([]byte{0, 69, 79, 70}, Buf[:n]) {

					File.Sync()

					File.Close()

					break

				}

				File.Write(Buf[:n])

			}

		}

	}

}

func client() {

	con, e := net.Dial("udp", "127.0.0.1:1789")

	if e != nil {

		fmt.Println(e)

		return

	}

	defer con.Close()

	var info Fileinfo = Fileinfo{Name: "WinMD5.exe", Path: "D:"}

	b, _ := json.Marshal(info)

	con.Write([]byte(b))

	Buf := make([]byte, 1024)

	n, _ := con.Read(Buf)

	if string(Buf[:n]) == "OK" {

		File, _ := os.Open("3.go")

		for {

			Buf := make([]byte, 4096)

			n, e := File.Read(Buf)

			if e != nil {

				if e == io.EOF {

					break

				}

				fmt.Println(e)

				break

			}

			con.Write(Buf[:n])

		}

		con.Write([]byte{0, 69, 79, 70})

	}

}