Please implement a feature where one can check if stdout wants input. #16214
Description
I had a little freetime so I decided to rewrite all my bash scripts in JavaScript (NodeJS - ES6) with child processes. Everything went smoothly until I wanted to automate user input.
Yes, you can do automate the user input. But there is one Problem - you can't determine if the given data event is a feedback or a request for input. At least I can't find a way to do it.
So basically you can do this:
// new Spawn.
let spawn = require('child_process');
// new ufw process.
let ufw = spawn('ufw', ['enable']);
// Use defined input.
ufw.stdin.setEncoding('utf-8');
ufw.stdout.pipe(process.stdout);
ufw.stdin.write('y\n');
// Event Standard Out.
ufw.stdout.on('data', (data) => {
console.log(data.toString('utf8'));
});
// Event Standard Error.
ufw.stderr.on('data', (err) => {
// Logerror.
console.log(err);
});
// When job is finished (with or without error) it ends up here.
ufw.on('close', (code) => {
// Check if there were errors.
if (code !== 0) console.log('Exited with code: ' + code.toString());
// End input stream.
ufw.stdin.end();
});
The given example only works if there is one guaranteed input. But what about multiple inputs? And how can I tell my code to use the right input on the right time?
I don't think that nodejs has a built in feature which will tell me "Ok, now I need input!". Because the only way to get a non error feedback is through:
// Event Standard Out.
process.stdout.on('data', (data) => {
// Feedback.
console.log(data);
});