在同一进程中启动多个 REPL 实例


¥Starting multiple REPL instances in the same process

可以针对单个正在运行的 Node.js 实例创建并运行多个 REPL 实例,这些实例共享一个 global 对象(通过将 useGlobal 选项设置为 true),但具有单独的 I/O 接口。

¥It is possible to create and run multiple REPL instances against a single running instance of Node.js that share a single global object (by setting the useGlobal option to true) but have separate I/O interfaces.

例如,以下示例在 stdin、Unix 套接字和 TCP 套接字上提供了单独的 REPL,它们共享同一个 global 对象:

¥The following example, for instance, provides separate REPLs on stdin, a Unix socket, and a TCP socket, all sharing the same global object:

import net from 'node:net';
import repl from 'node:repl';
import process from 'node:process';
import fs from 'node:fs';

let connections = 0;

repl.start({
  prompt: 'Node.js via stdin> ',
  useGlobal: true,
  input: process.stdin,
  output: process.stdout,
});

const unixSocketPath = '/tmp/node-repl-sock';

// If the socket file already exists let's remove it
fs.rmSync(unixSocketPath, { force: true });

net.createServer((socket) => {
  connections += 1;
  repl.start({
    prompt: 'Node.js via Unix socket> ',
    useGlobal: true,
    input: socket,
    output: socket,
  }).on('exit', () => {
    socket.end();
  });
}).listen(unixSocketPath);

net.createServer((socket) => {
  connections += 1;
  repl.start({
    prompt: 'Node.js via TCP socket> ',
    useGlobal: true,
    input: socket,
    output: socket,
  }).on('exit', () => {
    socket.end();
  });
}).listen(5001);const net = require('node:net');
const repl = require('node:repl');
const fs = require('node:fs');

let connections = 0;

repl.start({
  prompt: 'Node.js via stdin> ',
  useGlobal: true,
  input: process.stdin,
  output: process.stdout,
});

const unixSocketPath = '/tmp/node-repl-sock';

// If the socket file already exists let's remove it
fs.rmSync(unixSocketPath, { force: true });

net.createServer((socket) => {
  connections += 1;
  repl.start({
    prompt: 'Node.js via Unix socket> ',
    useGlobal: true,
    input: socket,
    output: socket,
  }).on('exit', () => {
    socket.end();
  });
}).listen(unixSocketPath);

net.createServer((socket) => {
  connections += 1;
  repl.start({
    prompt: 'Node.js via TCP socket> ',
    useGlobal: true,
    input: socket,
    output: socket,
  }).on('exit', () => {
    socket.end();
  });
}).listen(5001);

从命令行运行此应用将在标准输入上启动 REPL。其他 REPL 客户端可以通过 Unix 套接字或 TCP 套接字连接。例如,telnet 可用于连接 TCP 套接字,而 socat 可用于连接 Unix 和 TCP 套接字。

¥Running this application from the command line will start a REPL on stdin. Other REPL clients may connect through the Unix socket or TCP socket. telnet, for instance, is useful for connecting to TCP sockets, while socat can be used to connect to both Unix and TCP sockets.

通过从基于 Unix 套接字的服务器而不是标准输入启动 REPL,可以连接到长时间运行的 Node.js 进程而无需重新启动它。

¥By starting a REPL from a Unix socket-based server instead of stdin, it is possible to connect to a long-running Node.js process without restarting it.