Golang transfer file with socket

package main
import (
    "bufio"
    "code.google.com/p/mahonia"
    "fmt"
    "io"
    "net"
    "os"
)
func main() {
    fmt.Println("create a server or client?")
    reader := bufio.NewReader(os.Stdin)
    input, _, _ := reader.ReadLine()
    if string(input) == "server" {
        Server()
    }
    if string(input) == "client" {
        Client()
    } else {
        fmt.Println(Show("err arguments,entering again!.\r\n  alternaltive argument is server or client"))
        os.Exit(0)
    }
}
func Show(s string) string {
    enc := mahonia.NewEncoder("gbk") //中文转码有错误的函数。
    return enc.ConvertString(s)
}
func Server() {
    exit := make(chan bool)
    ip := net.ParseIP("127.0.0.1")
    addr := net.TCPAddr{ip, 8888, ""}
    go func() {
        listener, err := net.ListenTCP("tcp", &addr) //TCPListener listen
        if err != nil {
            fmt.Println("Initialize error", err.Error())
            exit <- true
            return
        }
        fmt.Println("Server listening...")
        tcpcon, err := listener.AcceptTCP() //TCPConn client
        if err != nil {
            fmt.Println(err.Error())
            //continue
        }
        fmt.Println("Client connect")
        data := make([]byte, 1024)
        if err != nil {
            fmt.Println("tcpcon.Read(data)" + err.Error())
        }
        //recv file name
        wc, err := tcpcon.Read(data)
        fo, err := os.Create("F:\\uploads\\" + string(data[0:wc]))
        if err != nil {
            fmt.Println("os.Create" + err.Error())
        }
        fmt.Println("the file's name is:", string(data[0:wc]))
        //recb file size
        wc, err = tcpcon.Read(data)
        fmt.Println("the file's size is:", string(data[0:wc]))
        defer fo.Close()
        for {
            c, err := tcpcon.Read(data) //???为何调用conn类的Read
            if err != nil {
                fmt.Println("tcpcon.Read(data)" + err.Error())
            }
            if string(data[0:c]) == "filerecvend" {
                fmt.Println("string(data[0:c]) == filerecvend is true")
                tcpcon.Write([]byte("file recv finished!\r\n"))
                tcpcon.Close()
                break
            }
            //write to the file
            _, err = fo.Write(data[0:c])
            if err != nil {
                fmt.Println("write err" + err.Error())
            }
        }
    }()
    <-exit
    fmt.Println(Show("server close!"))
}
func Client() {
    fmt.Println("send ur file to the destination", "input ur filename:")
    reader := bufio.NewReader(os.Stdin)
    input, _, _ := reader.ReadLine()
    fmt.Println(string(input))
    fi, err := os.Open(string(input))
    if err != nil {
        panic(err)
    }
    defer fi.Close()
    fiinfo, err := fi.Stat()
    fmt.Println("the size of file is ", fiinfo.Size(), "bytes") //fiinfo.Size() return int64 type
    conn, err := net.Dial("tcp", "127.0.0.1:8888")
    if err != nil {
        fmt.Println(Show("connect server fail！"), Show(err.Error()))
        return
    }
    defer conn.Close()
    //send filename
    _, err = conn.Write(input)
    if err != nil {
        fmt.Println("conn.Write", err.Error())
    }
    //send file size
    _, err = conn.Write([]byte(string(fiinfo.Size())))
    if err != nil {
        fmt.Println("conn.Write", err.Error())
    }
    buff := make([]byte, 1024)
    for {
        n, err := fi.Read(buff)
        if err != nil && err != io.EOF {
            panic(err)
        }
        if n == 0 {
            conn.Write([]byte("filerecvend"))
            fmt.Println("filerecvend")
            break
        }
        _, err = conn.Write(buff)
        if err != nil {
            fmt.Println(err.Error())
        }
    }
}