I'm working on a small cli tool that can automatically deploy Google Home actions based on the projects that are setup in a directory.

Basically my script checks the directories and then asks which project to deploy. The actual mand that should run is ing from Google's cli gactions

To run it with arguments I setup a spawned process in my node-script:

const { spawn } = require('child_process')
const child = spawn('./gactions', [
    'update',
    '--action-package',
    '<PATH-TO-PACKAGE>',
    '--project',
    '<PROJECT-NAME>'
])

child.stdout.on('data', data => {
    console.log(data)
}

However, the first time a project is deployed, the gactions cli will prompt for an authorization code. Running the code above, I can actually see the prompt, but the script won't proceed when actually entering that code.

I guess there must be some way in the child process to capture that input? Or isn't this possible at all?

I'm working on a small cli tool that can automatically deploy Google Home actions based on the projects that are setup in a directory.

Basically my script checks the directories and then asks which project to deploy. The actual mand that should run is ing from Google's cli gactions

To run it with arguments I setup a spawned process in my node-script:

const { spawn } = require('child_process')
const child = spawn('./gactions', [
    'update',
    '--action-package',
    '<PATH-TO-PACKAGE>',
    '--project',
    '<PROJECT-NAME>'
])

child.stdout.on('data', data => {
    console.log(data)
}

However, the first time a project is deployed, the gactions cli will prompt for an authorization code. Running the code above, I can actually see the prompt, but the script won't proceed when actually entering that code.

I guess there must be some way in the child process to capture that input? Or isn't this possible at all?

• javascript
• node.js
• spawn
• google-home

• The child process's stdin, stdout, and stderr are streams, so you can manipulate them as you like. The node documentation gives you a very simple example as a starting point. – lependu Commented Nov 19, 2018 at 15:00
• Ok. But how do I capture that input when prompted for? – Maarten Commented Nov 19, 2018 at 16:03

2 Answers 2

Simply pipe all standard input from the parent process to the child and all output from the child to the parent.

The code below is a full wrapper around any shell mand, with input/output/error redirection:

const { spawn } = require('child_process');
var child = spawn(mand, args);

child.stdout.pipe(process.stdout);
child.stderr.pipe(process.stderr);
process.stdin.pipe(child.stdin);

child.on('exit', () => process.exit())

Note that if you pipe stdout you don't need handle the data event anymore.

require( "child_process" ).spawnSync( "sh", [ "-c", "npm adduser" ], { stdio: "inherit", stdin: "inherit" } );

this will execute the mand given as we normally do in terminal.