tcp连接

服务器端

package main
import (
	"fmt"
	"net"
	"strings"
)
func  HandleConnect( conn net.Conn)  {
		defer conn.Close()
		addr:=conn.RemoteAddr()
		fmt.Println(addr,"客户端成功连接")
		buf:=make([]byte,4096)
		for {
			n,err:=conn.Read(buf)
			if "exit\n" == string(buf[:n]) ||  "exit\r\n" == string(buf[:n]){
				fmt.Println("客户端关闭连接")
				return
			}
			if n ==0 {
				fmt.Println("Client is close")
				return
			}
			if err != nil {
				fmt.Println("conn Read err",err)
				return
			}
			fmt.Println("服务器读到客户端数据:",string(buf[:n]))
			conn.Write([]byte(strings.ToUpper(string(buf[:n]))))
		}
}
func main(){
	listener,err:= net.Listen("tcp","127.0.0.1:9001")
	if err != nil {
		fmt.Println("net.listen is error")
		return
	}
	defer listener.Close()
	fmt.Println("服务器等待客户端连接...")
	for {
		conn,err:= listener.Accept()
		if err != nil {
			fmt.Println("accept is error") 
			return
		}
		go HandleConnect(conn)
	}
}

客户端

package main

import (
	"fmt"
	"net"
	"os"
)

func main(){
	conn,err:=net.Dial("tcp","127.0.0.1:9001")
	if err != nil {
		fmt.Println("connect server is error")
		return
	}
	defer conn.Close()

	go func(){
		str:=make([]byte,4096)
		for {
			n,err:=os.Stdin.Read(str)
			if n ==0 {
				fmt.Println("server is close")
				return
			}
			if err != nil {
				fmt.Println("os.Stdin is error")
				continue
			}
			conn.Write(str[:n])
		}
	}()
	//读取服务器
	buf:=make([]byte,4096)
	for {
		n,err:=conn.Read(buf)
		if n == 0 {
			fmt.Println("服务端关闭连接了...")
			return
		}
		if "exit\n" == string(buf[:n]) || "exit\r\n" == string(buf[:n]) {
			fmt.Println("客户端关闭连接")
			return
		}
		if err != nil {
			fmt.Println("os.buf is error")
			return
		}
		fmt.Println("客户端读到服务端数据：", string(buf[:n]))
	}
}

使用案例【tcp发送文件】------------------------------------------------

服务端

package main

import (
	"fmt"
	"io"
	"log"
	"net"
	"os"
)
func recvFile(conn net.Conn,fileName string){
	f,err:=os.Create(fileName)
	if err != nil {
		log.Println("Create File is error")
		return
	}
	defer f.Close()
	buf:=make([]byte,4096)
	for {
		n,_:=conn.Read(buf)
		if n==0 {
			fmt.Println("finsh")
			return
		}
		f.Write(buf[:n])
	}
}

func main(){
	listener,err:= net.Listen("tcp","127.0.0.1:8007")
	if err != nil {
		fmt.Println("net.Listen is error")
		return
	}
	defer listener.Close()
	conn,err:=listener.Accept()
	//获取文件名字
	bufName:=make([]byte,4096)
	n,err:=conn.Read(bufName)
	if err != nil {
		if err == io.EOF {
			fmt.Println("finish")
		}
		return
	}
	fileName:= string(bufName[:n])
	recvFile(conn,fileName)
}

客户端

package main

import (
	"fmt"
	"io"
	"log"
	"net"
	"os"
)
func readFile(conn net.Conn,path string){
	fd,_:=os.Open(path)
	buf:=make([]byte,4096)
	for {
		n,err:=fd.Read(buf)
		if err == io.EOF {
			fmt.Println("send file fiinish")
			return
		}
		conn.Write(buf[:n])
	}
	defer fd.Close()
}
func main(){
	lists:= os.Args
	if len(lists) != 2 {
		log.Println("params is errors")
		return
	}
	path:= lists[1]

	conn,err:=net.Dial("tcp","127.0.0.1:8007")
	if err != nil {
		fmt.Println("conn is erros")
		return
	}
	defer conn.Close()
	fileInfo,_:= os.Stat(path)
	fileName := fileInfo.Name()
	fmt.Println(fileName)
	conn.Write([]byte(fileName))//发送文件名字
	readFile(conn,path)
}