如何在 node.js 中实时生成 childProcess.stdout

Question

I am using Node to call a command which sometimes returns an interactive shell prompt. And I'm using ChildProcess.spawn to create the subprocess.

Here's my node.js code:

let ps = ChildProcess.spawn('command', ['arg1', 'arg2'], { interactive: true })

ps.stdout.on('data', data => {
  console.log('GOT SOME DATA:', data.toString())
})

ps.stderr.on('data', data => {
  console.log('ERROR:', data.toString())
})

And my script sometimes has an interactive prompt like:

Enter Password:

I would like to be able to listen for this text (something like if (line.match(/^Enter Password:/)) { ... } , and then write to stdin , but ps.stdout.on('data', ...) doesn't get called until the process exits.

How do I flush the process's stdout stream and get the data right away (or even poll for it)?

Note: I've also tried pty.js and no luck, it seems to just completely stall.

Answer 1

Your code is working fine , I was just receiving a buffer and not a string , try with string interpolation :

let ps = ChildProcess.spawn('ls', [], { interactive: true})

ps.stdout.on('data', data => {
  console.log(`Got some data : ${data}`)
})

ps.stderr.on('data', data => {
  console.log(`Got some error : ${data}`)
})