package main

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

func gogopowerrangers(commSock net.Conn) {


  for ;; { // Server loop to interact with the client
      buf := make([]byte, 256) // for buffering // but redecl :-(
      bufLen, err := commSock.Read(buf) // try a read  buffer from the Sock
      if err != nil {
          fmt.Fprintf(os.Stderr, "Error when reading from socket: %s\n", err)
          return
      }
      if bufLen == 0 {
          fmt.Printf("Connection closed by remote host\n")
          return
      }
      hashMap := map[string]string {
        "mdp": "Connexion réussie",
      }
      buf = buf[:bufLen-1]  // this is to ignore '\n', counting from 0
      s := string(buf)
      reponse := "Mauvais mot de passe"

      if val, ok := hashMap[s]; ok {
        reponse = val
      }
      //fmt.Printf("Length of read buffer = %s\n",s)
      //fmt.Printf("Length of read buffer = %s\n",reponse)
      //fmt.Printf("Client at %s says '%s'\n", commSock.RemoteAddr(), buf)

      // prepare the response
      writelen, err := commSock.Write([]byte("Serv ACK! > "+reponse+"\n"))
      if err != nil {
        fmt.Fprintf(os.Stderr, "Could not write to socket: %s\n", err)
      } else {
        fmt.Printf("Wrote %d bytes to socket\n", writelen)
      }
      // send a 'response' to the client via the same connScock
      writtenLen, err := commSock.Write([]byte(reponse))
      if err != nil {
         fmt.Fprintf(os.Stderr, "Could not write to socket: %s\n", err)
       } else {
         fmt.Printf("Wrote %d bytes to socket\n", writtenLen)
       }
       exit()
    }//for
}

func exit() {
      os.Exit(0)
}


func main() {



    sockListener, err := net.Listen("tcp", "127.0.0.1:2056")
    if err != nil {
        fmt.Fprintf(os.Stderr, "Could not listen on socket: %s\n", err)
        return
    }

    for {
    commSock, err := sockListener.Accept()
    if err != nil {
        fmt.Fprintf(os.Stderr, "Could not accept connection on socket: %s\n", err)
        return
    }

      go gogopowerrangers(commSock)
    }
}



client :

package main

import "net"
import "fmt"
import "bufio"
import "os"

func main() {

  // connect to this socket
  conn, _ := net.Dial("tcp", "127.0.0.1:2056")


  for  {
    // read in input from stdin
    reader := bufio.NewReader(os.Stdin)
    fmt.Print("Password: ")
    text, _ := reader.ReadString('\n')
    // send to socket
    fmt.Fprintf(conn, text)
    // listen for reply
    message, _ := bufio.NewReader(conn).ReadString('\n')
    fmt.Print("Message from server: "+message)
  }
}