Node.js 网络套接字

Question

我正在使用 net 模块创建侦听器，但遇到了一些问题。我试图让它等到它完成将“文本”写入客户端，然后客户端才能再次键入。如果我不这样做并且我坚持输入它只会让你能够在导致奇怪格式等的文本之间写入输入。

那么我怎样才能让它等到它被写入客户端呢？

代码：

const net = require('net');
const server = new net.Server();

server.on('connection', async function (socket) {
    console.log("Client connected!");

    socket.on('data', async function (data) {
        socket.setEncoding('utf8');
        let input = data.toString().replace(/(\r\n|\n|\r)/gm, "");
        if (input == "echo")
            socket.write("$ ");
        else
            socket.write("invalid command");
    });
});

server.listen(1337, function() {
    console.log("listening");
});

图片： https://imgur.com/a/lc21Y13

编辑： 这是在本地主机上，假设我将它托管在服务器上，所以会有更高的 ping 它更糟糕。

编辑： 这是托管在服务器上时的图片： https://imgur.com/a/LIKRRr9

编辑： 我试过用 SSH 代替 telnet 和 raw，现在得到了基本相同的结果。

图片： https://imgur.com/a/XJmpGSa

代码：

var fs = require('fs');
var username = null;
var ssh2 = require('ssh2');

new ssh2.Server({
    hostKeys: [fs.readFileSync('ssh.key')]
}, function (client) {
    console.log('Client connected!');

    client.on('authentication', function (ctx) {

        if (ctx.method !== 'password') return ctx.reject(['password']);

        if (ctx.method === 'password') {
            username = ctx.username;

            console.log(username);
            console.log(ctx.password);
            ctx.accept();
        }
        else {
            console.log("rejected.");
            ctx.reject();
        }

    }).on('ready', function () {
        console.log('Client authenticated!');

        client.on('session', function (accept, reject) {
            var session = accept();

            session.once('shell', function (accept, reject, info) {
                var stream = accept();

                stream.write("$ ");

                stream.on('data', function (data) {

                    var args = data.toString().split(" ");
                    console.log(args);

                    switch (args[0]) {
                        case "echo":
                            args.shift();
                            stream.write(args.join(" ") + "\r\n");
                            break;
                        case "whoami":
                            stream.write(username + "\r\n");
                            break;
                        case "exit":
                            stream.exit(0);
                            stream.end();
                            stream = undefined;
                            break;
                        default:
                            stream.stderr.write(args[0] + ": No such command!\r\n");
                            break;
                    }
                    if (typeof stream != 'undefined') {
                        stream.write("$ ");
                    }
                });
            });
        });
    }).on('end', function () {
        console.log('Client disconnected');
    });
}).listen(1337, function () {
    console.log('Listening on port ' + this.address().port);
});

Answer 1

试试这个。这段代码所做的只是缓冲，直到从客户端接收到 \n 输入。

const net = require("net");
const readline = require("readline");

const execCommand = (command, args, socket) => {
  return new Promise((res, rej) => {
    setTimeout(() => {
      // to clear the terminal
      socket.write("\u001B[2J\u001B[0;0f");
      socket.write(
        `Executed command: ${command} with args: ${args} and result was: ${Math.random()}`
      );
      socket.write('\n>')
      res();
    }, 3000);
  });
};

const server = net.createServer((socket) => {
  socket.write("Connected");
  // nice prompt
  socket.write("\n>");

  const rl = readline.createInterface({
    input: socket,
    output: socket,
  });

  rl.on("line", (line) => {
    if (line.length === 0) {
      socket.write("No command to execute!");
      socket.write('\n>')
      return;
    }
    // destructuring command and args
    // E.g. command arg1 arg2 ....
    const [command, ...args] = line.split(" ");
    execCommand(command, args, socket);
  });
});

server.listen(1337, "127.0.0.1");