backend.js

   1 const { spawn } = require("child_process");
   2 const WebSocket = require("ws");
   3
   4 const run = () => {
   5         const wss = new WebSocket.Server({ port: 8081 });
   6
   7         wss.on("connection", ws => {
   8                 setupConnection(ws);
   9         });
  10 };
  11 run();
  12 const setupConnection = ws => {
  13         let ed = spawn("ed");
  14         let open = true;
  15         ed.stdout.on("data", data => {
  16                 ws.send(`${data}`);
  17         });
  18
  19         ed.on("close", code => {
  20                 open = false;
  21                 ws.close();
  22         });
  23         ws.on("message", message => {
  24                 if (open) {
  25                         ed.stdin.write(message);
  26                 }
  27         });
  28
  29         ws.send("Welcome to Ed on the Web!\n");
  30 };