GO编程，在读取器事件上阻止读取功能

Question

I am a beginner in Go programming and I am confused about a problem about bufio readers. I'm programming a kind of chat client who must display and send our messages in live time. But messages that I receive are not displayed until I press enter in my terminal. After few tests, it seems to be my "inputListener()" function being the problem because, if I put it after reading messages from server, messages from server are displaying first. I supposed that the Read function may blocked my loop until it get a ' ' or something like that.

Here is my code:

package main
import "os"
import "strconv"
import "net"
import "bufio"

/*Recovery our input message into a buffer*/
func inputListener()([] byte){
    buf := make([]byte, 512)
    readerInput := bufio.NewReader(os.Stdin)
    _, err := readerInput.Read(buf)
    if err != nil{
        panic("Error reading input.")
        os.Exit(0)
    }
    return buf
}


func main(){
if len(os.Args) != 3{
    println("Usage: ",os.Args[0], " <host> <port>
")
    os.Exit(0)
}

//Recovery the port.
port, err := strconv.Atoi(os.Args[2])
if err != nil{
  panic("Error during the port recovery
")
  os.Exit(0)
}
println(port)

/*Join the adresse*/
addr := os.Args[1] + ":" + strconv.Itoa(port)
println(addr)

/*  sources -- https://golang.org/pkg/net/  */

conn, err := net.Dial("tcp", addr)
if err != nil{
    panic("Error connecting " + addr)
    os.Exit(0)
}


buf := make([]byte, 512)
t := make([]byte, 512)

for {

    /*Receive data from server*/
    size, err := conn.Read(buf)
    if err != nil {
        panic("Error reading output.")
        os.Exit(0)
    }
    if size >= 0{
        print(string(buf[0:size]))
    }

    /*Data we need to send*/
    t = inputListener()
    if len(t) >= 0{
        conn.Write(t)
    }
} 

conn.Close()
}

I need to press enter per messages received :/

Thank you in advance for your answers !

Answer 1

You be try something like this:

package main

import (
    "bufio"
    "io"
    "net"
    "os"
    "strconv"
)

/*Recovery our input message into a buffer*/
func inputListener() []byte {
    buf := make([]byte, 512)
    readerInput := bufio.NewReader(os.Stdin)
    _, err := readerInput.Read(buf)
    if err != nil {
        panic("Error reading input.")
    }
    return buf
}

func main() {
    if len(os.Args) != 3 {
        println("Usage: ", os.Args[0], " <host> <port>
")
        os.Exit(0)
    }

    //Recovery the port.
    port, err := strconv.Atoi(os.Args[2])
    if err != nil {
        panic("Error during the port recovery
")
    }
    println(port)

    /*Join the adresse*/
    addr := os.Args[1] + ":" + strconv.Itoa(port)
    println(addr)

    /*  sources -- https://golang.org/pkg/net/  */

    conn, err := net.Dial("tcp", addr)
    if err != nil {
        panic("Error connecting " + addr)
    }
    defer conn.Close()

    go io.Copy(os.Stdout, conn)

    r := bufio.NewReader(os.Stdin)
    for {
        p, err := r.ReadSlice('
')
        if err != nil {
            panic("Error reading output.")
        }
        conn.Write(p)
    }
}