Capture input in the child process after spawn in node

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 command that should run is coming 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?

edited Nov 26 '18 at 16:35

mihai

23.7k74068

asked Nov 19 '18 at 14:37

Maarten

270417

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
Nov 19 '18 at 15:00

Ok. But how do I capture that input when prompted for?

– Maarten
Nov 19 '18 at 16:03

add a comment |

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 command that should run is coming 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)

}

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

edited Nov 26 '18 at 16:35

mihai

23.7k74068

asked Nov 19 '18 at 14:37

Maarten

270417

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
Nov 19 '18 at 15:00

Ok. But how do I capture that input when prompted for?

– Maarten
Nov 19 '18 at 16:03

add a comment |

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 command that should run is coming 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)

}

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

edited Nov 26 '18 at 16:35

mihai

23.7k74068

asked Nov 19 '18 at 14:37

Maarten

270417

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 command that should run is coming 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)

}

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

edited Nov 26 '18 at 16:35

mihai

23.7k74068

asked Nov 19 '18 at 14:37

Maarten

270417

edited Nov 26 '18 at 16:35

mihai

23.7k74068

asked Nov 19 '18 at 14:37

Maarten

270417

edited Nov 26 '18 at 16:35

mihai

23.7k74068

edited Nov 26 '18 at 16:35

mihai

23.7k74068

edited Nov 26 '18 at 16:35

mihai

23.7k74068

asked Nov 19 '18 at 14:37

Maarten

270417

asked Nov 19 '18 at 14:37

Maarten

270417

asked Nov 19 '18 at 14:37

Maarten

270417

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
Nov 19 '18 at 15:00

Ok. But how do I capture that input when prompted for?

– Maarten
Nov 19 '18 at 16:03

add a comment |

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
Nov 19 '18 at 15:00

Ok. But how do I capture that input when prompted for?

– Maarten
Nov 19 '18 at 16:03

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
Nov 19 '18 at 15:00

Ok. But how do I capture that input when prompted for?

– Maarten
Nov 19 '18 at 16:03

add a comment |

1 Answer
1

active

oldest

votes

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 command, with input/output/error redirection:

const { spawn } = require('child_process');

var child = spawn(command, 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.

edited Nov 22 '18 at 14:22

answered Nov 22 '18 at 14:08

mihai

23.7k74068

That worked. I probably need to read-up some more about piping data in node. Any recommendations by any chance for good documentation on this subject?

– Maarten
Nov 26 '18 at 16:12

you should read about working with streams, that's the wider topic. The official node docs about Stream is a good starting point, but you can always google for more

– mihai
Nov 26 '18 at 16:18

Cool. Thanks mihai!

– Maarten
Nov 26 '18 at 16:24

add a comment |

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1 Answer
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1 Answer
1

active

oldest

votes

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 command, with input/output/error redirection:

const { spawn } = require('child_process');

var child = spawn(command, 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.

edited Nov 22 '18 at 14:22

answered Nov 22 '18 at 14:08

mihai

23.7k74068

That worked. I probably need to read-up some more about piping data in node. Any recommendations by any chance for good documentation on this subject?

– Maarten
Nov 26 '18 at 16:12

you should read about working with streams, that's the wider topic. The official node docs about Stream is a good starting point, but you can always google for more

– mihai
Nov 26 '18 at 16:18

Cool. Thanks mihai!

– Maarten
Nov 26 '18 at 16:24

add a comment |

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 command, with input/output/error redirection:

const { spawn } = require('child_process');

var child = spawn(command, 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.

edited Nov 22 '18 at 14:22

answered Nov 22 '18 at 14:08

mihai

23.7k74068

That worked. I probably need to read-up some more about piping data in node. Any recommendations by any chance for good documentation on this subject?

– Maarten
Nov 26 '18 at 16:12

you should read about working with streams, that's the wider topic. The official node docs about Stream is a good starting point, but you can always google for more

– mihai
Nov 26 '18 at 16:18

Cool. Thanks mihai!

– Maarten
Nov 26 '18 at 16:24

add a comment |

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 command, with input/output/error redirection:

const { spawn } = require('child_process');

var child = spawn(command, 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.

edited Nov 22 '18 at 14:22

answered Nov 22 '18 at 14:08

mihai

23.7k74068

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 command, with input/output/error redirection:

const { spawn } = require('child_process');

var child = spawn(command, 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.

edited Nov 22 '18 at 14:22

answered Nov 22 '18 at 14:08

mihai

23.7k74068

edited Nov 22 '18 at 14:22

answered Nov 22 '18 at 14:08

mihai

23.7k74068

answered Nov 22 '18 at 14:08

mihai

23.7k74068

answered Nov 22 '18 at 14:08

mihai

23.7k74068

That worked. I probably need to read-up some more about piping data in node. Any recommendations by any chance for good documentation on this subject?

– Maarten
Nov 26 '18 at 16:12

you should read about working with streams, that's the wider topic. The official node docs about Stream is a good starting point, but you can always google for more

– mihai
Nov 26 '18 at 16:18

Cool. Thanks mihai!

– Maarten
Nov 26 '18 at 16:24

add a comment |

That worked. I probably need to read-up some more about piping data in node. Any recommendations by any chance for good documentation on this subject?

– Maarten
Nov 26 '18 at 16:12

you should read about working with streams, that's the wider topic. The official node docs about Stream is a good starting point, but you can always google for more

– mihai
Nov 26 '18 at 16:18

Cool. Thanks mihai!

– Maarten
Nov 26 '18 at 16:24

That worked. I probably need to read-up some more about piping data in node. Any recommendations by any chance for good documentation on this subject?

– Maarten
Nov 26 '18 at 16:12

you should read about working with streams, that's the wider topic. The official node docs about Stream is a good starting point, but you can always google for more

– mihai
Nov 26 '18 at 16:18

Cool. Thanks mihai!

– Maarten
Nov 26 '18 at 16:24

add a comment |

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