CODEWITHSUNDEEP
node.jsbashshell
Alexander Mills
Alexander Mills

Reputation: 100370

Send the same bash process multiple commands

I have the following code:

const cp = require('child_process');

function spawnInstance () {
  const c = cp.spawn('bash');
  return command => {
    return new Promise((resolve, reject) => {
      c.stdout.on('data', d => resolve(String(d || 'empty stdout.\n')));
      c.stderr.once('data', d => reject(String(d || 'empty stderr.\n')));
      c.stdin.write(`echo "${command}" | bash;`);  
      c.stdin.write('\n');
    });
  };
}

(async () => {
  const bash = spawnInstance();
  console.log(await bash('ls'));
  console.log(await bash('cd node_modules'));
  console.log(await bash('ls'));
})()
.catch(e =>
  console.error(e)
);

What I want to do is to reuse the same bash process, and get the stdout for each command that I run. Is there a way to do this, or do I need to start a new bash process for each command I run?

The problem is my code gets stuck on the cd node_modules command.

Upvotes: 2

Views: 261

Answers (2)

scrat.squirrel
scrat.squirrel

Reputation: 3836

This article states that now there is an NPM package that allows for a persistent bash process.

The github url:

https://github.com/bitsofinfo/stateful-process-command-proxy

Quote from the him homepage:

This node module can be used for proxying long-lived bash process, windows console etc. It works and has been tested on both linux, os-x and windows hosts running the latest version of node.

Upvotes: 1

jmd_dk
jmd_dk

Reputation: 13120

I don't think you can keep a bash process alive after a bash call and then re-enter the process with some new call. You can however run multiple bash commands after each other in the same process, e.g. by separating them with semicolons:

console.log(await bash('cd node_modules; ls'));

Upvotes: 1

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