我有一個(gè)小型 TCP 服務(wù)器正在運(yùn)行，用戶可以通過(guò) telnet 進(jìn)行連接。有一個(gè)“菜單”選項(xiàng)循環(huán)（例如觸發(fā)單個(gè)字符輸入），選擇“L”選項(xiàng)允許連接的用戶“留言”。然而：從連接菜單中進(jìn)行選擇 (L) 時(shí) - 它會(huì)復(fù)制/重復(fù)菜單然后，需要額外/不必要的按鍵才能看到回顯給用戶的類型我懷疑我有循環(huán)問(wèn)題，但我不知道它在哪里崩潰。有任何想法嗎？package mainimport ( "bytes" "fmt" "log" "net")const ( port = "5555")var arr []stringtype Client struct { c net.Conn dataType string menuCurr string}func NewClient() *Client { return &(Client{})}func waitForInput(didInput chan<- bool) { // Wait for a valid input here didInput <- true}func main() { log.Printf("Hello Server!") service := ":5555" tcpAddr, error := net.ResolveTCPAddr("tcp", service) if error != nil { log.Printf("Error: Could not resolve address") } else { netListen, error := net.Listen(tcpAddr.Network(), tcpAddr.String()) if error != nil { log.Fatal(error) } else { defer netListen.Close() for { log.Printf("Waiting for clients") conn, error := netListen.Accept() if error != nil { log.Print("Client error: ", error) } else { log.Printf("Client connected %s -> %s \n", conn.RemoteAddr(), conn.LocalAddr()) go handler(conn) } } } }}func removeClient(conn net.Conn) { log.Printf("Client %s disconnected", conn.RemoteAddr()) conn.Close()}func handler(conn net.Conn) { defer removeClient(conn) errorChan := make(chan error) dataChan := make(chan []byte) // Set defaults for incoming connections var s *Client s = NewClient() s.c = conn s.dataType = "key" s.menuCurr = "connect" // first menu every user sees
2 回答
慕運(yùn)維8079593
TA貢獻(xiàn)1876條經(jīng)驗(yàn) 獲得超5個(gè)贊
所以你幾乎明白了！
需要額外按鍵的原因是您的選擇案例在收到另一個(gè)字符之前不會(huì)處理?；旧夏懵浜罅艘粋€(gè)角色。當(dāng)您從用戶那里收集消息時(shí)，您還需要注意這一點(diǎn)。
這是我能夠開始工作的。我的 telnet 客戶端在我點(diǎn)擊返回之前不會(huì)發(fā)送（我在 Windows 上，為什么是 \r\n 而不是只是 \n）所以我需要去除那些額外的字符。
package main
import (
"bytes"
"fmt"
"log"
"net"
"strings"
)
const (
port = "5555"
)
var arr []string
type Client struct {
c net.Conn
dataType string
menuCurr string
}
func NewClient() *Client {
return &(Client{})
}
func waitForInput(didInput chan<- bool) {
// Wait for a valid input here
didInput <- true
}
func main() {
log.Printf("Hello Server!")
service := ":5555"
tcpAddr, error := net.ResolveTCPAddr("tcp", service)
if error != nil {
log.Printf("Error: Could not resolve address")
} else {
netListen, error := net.Listen(tcpAddr.Network(), tcpAddr.String())
if error != nil {
log.Fatal(error)
} else {
defer netListen.Close()
for {
log.Printf("Waiting for clients")
conn, error := netListen.Accept()
if error != nil {
log.Print("Client error: ", error)
} else {
log.Printf("Client connected %s -> %s \n", conn.RemoteAddr(), conn.LocalAddr())
go handler(conn)
}
}
}
}
}
func removeClient(conn net.Conn) {
log.Printf("Client %s disconnected", conn.RemoteAddr())
conn.Close()
}
func handler(conn net.Conn) {
defer removeClient(conn)
errorChan := make(chan error)
dataChan := make(chan []byte)
// Set defaults for incoming connections
var s *Client
s = NewClient()
s.c = conn
s.dataType = "key"
s.menuCurr = "connect" // first menu every user sees
go readWrapper(conn, dataChan, errorChan)
r := bytes.NewBuffer(make([]byte, 0, 1024))
// default menu
fmt.Fprintf(conn, "Select an option:\r\n\n[L] Leave Message\r\n[!] Disconnect\r\n\nCmd? ")
for {
select {
case data := <-dataChan:
// notice how i removed the current menu state
// "key" responds to single character input
if s.dataType == "key" {
t := strings.TrimSuffix(strings.TrimSuffix(string(data), "\r\n"), "\n")
switch t {
default:
fmt.Println("client hit invalid key...")
// remove the continue since the menu prints at the bottom
// continue
case "L", "l":
s.dataType = "text"
s.menuCurr = "message"
// notice the message here and the break instead of the continue.
// if we use continue instead it will wait until your user sends something
// with a break instead it will fall through and start collecting the text
fmt.Fprintf(conn, "Type a mesage. Escape to quit. \r\n\n")
break
case "!":
fmt.Fprintf(conn, " Bye!")
fmt.Println("client chose to exit...")
// tell current menu to exit
s.menuCurr = "exit"
}
}
// "Text" allows for free typing
if s.dataType == "text" {
for {
select {
case data := <-dataChan:
fmt.Fprintf(conn, string(data))
if bytes.Equal(data, []byte("\r\n")) || bytes.Equal(data, []byte("\r")) {
fmt.Fprintf(conn, "you typed: %q\r\n", r.String())
r.Reset()
s.dataType = "key"
s.menuCurr = "connect"
break
}
if bytes.Equal(data, []byte("\033")) || bytes.Equal(data, []byte("\033\r\n")) {
fmt.Fprintf(conn, "\r\nAborted!\r\n")
r.Reset()
s.dataType = "key"
s.menuCurr = "connect"
break
}
r.Write(data)
}
log.Printf("Client %s sent: %q", conn.RemoteAddr(), r.String())
if s.menuCurr == "connect" {
break
}
}
}
if s.menuCurr == "connect" {
fmt.Fprintf(conn, "Select an option:\r\n\n[L] Leave Message\r\n[!] Disconnect\r\n\nCmd? ")
}
// fall through statement to close connection
if s.menuCurr == "exit" {
break
}
// otherwise continue printing menu for invalid submissions
continue
case err := <-errorChan:
log.Println("An error occured:", err.Error())
return
}
fmt.Println("closing")
break
}
conn.Close()
}
func readWrapper(conn net.Conn, dataChan chan []byte, errorChan chan error) {
for {
buf := make([]byte, 1024)
reqLen, err := conn.Read(buf)
if err != nil {
errorChan <- err
return
}
dataChan <- buf[:reqLen]
}
}
楊魅力
TA貢獻(xiàn)1811條經(jīng)驗(yàn) 獲得超6個(gè)贊
使用 stocktelnet命令行程序時(shí)，它通常會(huì)與服務(wù)器協(xié)商以在LINEMODE. 在這種模式下，為了節(jié)省帶寬，用戶輸入將被緩沖。當(dāng)用戶點(diǎn)擊時(shí)，數(shù)據(jù)被刷新（即發(fā)送到服務(wù)器）：
Enter; 或者Ctrl-D
您可以在當(dāng)前狀態(tài)下使用您的服務(wù)器，但您必須鍵入擊鍵：L后跟Ctrl-D（強(qiáng)制刷新）。然后客戶端將收到預(yù)期的服務(wù)器響應(yīng)：type your message.
您的服務(wù)器代碼需要單次擊鍵 ( L, !)，因此如果您點(diǎn)擊-L然后Enter服務(wù)器收到的消息將是L\r\n，這是您的服務(wù)器代碼出錯(cuò)的地方：
if s.dataType == "key" {
switch string(data) {
default:
fmt.Printf("client hit invalid key... (%q)\n", string(data)) // <- `L\r\n`
continue
case "L", "l":
s.dataType = "text"
s.menuCurr = "message"
continue
case "!":
fmt.Fprintf(conn, " Bye!")
fmt.Println("client chose to exit...")
break
}
}
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