node async subprocess

cmd.js

//
// https://kisaragi-hiu.com/nodejs-cmd/
//
const { spawn } = require("child_process");
const process = require("process");

function cmd(...command) {
  let p = spawn(command[0], command.slice(1));
  return new Promise((resolveFunc) => {
    p.stdout.on("data", (x) => {
      process.stdout.write(x.toString());
    });
    p.stderr.on("data", (x) => {
      process.stderr.write(x.toString());
    });
    p.on("exit", (code) => {
      resolveFunc(code);
    });
  });
}

async function main() {
  await cmd("bash", "-c", "echo one; sleep 1; echo two; sleep 1");
  console.log("This must happen last.");
}

main();