Sending and receiving files golang

send

package main

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

func sendfile(conn net.Conn,path string)  {
	f,err:=os.Open(path)//读打开的文件
	if err!=nil{
		fmt.Println("os open err",err)
	}
	defer f.Close()
	buf := make([]byte,4096)//从本地读取数据传给接收端
	for{
		n,err3 := f.Read(buf)
		if err3!=nil{
			if err3==io.EOF{
				fmt.Println("发送数据完成")
			}else {
				fmt.Println("io read err",err3)
			}
			return
		}
		_,err:=conn.Write(buf[:n])
		if err!=nil{
			fmt.Println("conn write err",err)
			return
		}
	}

}

func main() {
	list := os.Args
	if len(list)!=2{
		fmt.Println("输入的格式为：文件路径 文件名")
		return
	}

	path:= list[1]
	fileinfo,err:=os.Stat(path)
	if err!=nil{
		fmt.Println("os stat err",err)
		return
	}

	filename:= fileinfo.Name()
	fmt.Println(filename)
	conn,err1 :=net.Dial("tcp","127.0.0.1:8004")
	if err1!=nil{
		fmt.Println("链接服务器失败")
		return
	}

	defer conn.Close()

	conn.Write([]byte(filename))

	buff := make([]byte,4096)
	n,err2:=conn.Read(buff)
	if err2 !=nil{
		fmt.Println("conn read err",err2)
	}

	if "ok"== string(buff[:n]){
		//写文件内容给服务器
		sendfile(conn,path)
	}
}

receive

package main

import (
	"fmt"
	"net"
	"os"
)
//写入数据到文件
func receivefile(conn net.Conn,filename string)  {
	//现在有文件名直接创建文件
	f,err:=os.Create(filename)
	if err!=nil{
		fmt.Println("os create file err",err)
		return
	}
	defer f.Close()
	buff:= make([]byte,4096)

	//从网络中读取数据,循环读
	for{
		n,_:= conn.Read(buff)
		if n == 0{
			fmt.Println("接收文件完成")
			return
		}
		//写入到文件
		f.Write(buff[:n])
	}
}

func main() {

	listenserver,err:=net.Listen("tcp","127.0.0.1:8004")
	if err!=nil{
		fmt.Println("net listen err",err)
	}

	defer listenserver.Close()

	conn,err2:= listenserver.Accept()
	if err2!=nil{
		fmt.Println("listenserver Accept err",err2)
	}

	defer conn.Close()
	//读取文件名字
	buff := make([]byte,4096)
	n,err3:=conn.Read(buff)

	if err3!=nil{
		fmt.Println("conn read err",err3)
	}

	filename := string(buff[:n])
	fmt.Println("接收到文件名",filename)

	conn.Write([]byte("ok"))
	//接收数据
	receivefile(conn,filename)

}