Redirect Output

[brianantonelli]

Would love to see a configuration option to redirect output to stderr instead of stdout. That way programs could support functionality like:

eval $(myapp dosomething)

Then we could then display the prompt through stderr so that only the response will be evaluated.

[remyrylan]

@brianantonelli I needed this too and just discovered it's already available.

const inquirer = require('inquirer')

const prompt = inquirer.createPromptModule({ output: process.stderr })

prompt(/* question array/object here */)

[SBoudrias]

@jrylan thanks for following up with the proper way to handle it <3

[brianantonelli]

Thx!

[brianantonelli]

So I'm still seeing some issues with this. I followed @jrylan 's instructions and my prompts are now directed to stderr which is perfect. However, I'm still seeing some rogue control characters being sent to stdout.. Thoughts?

^[[?25l^[[?25hexport AWS_ACCESS_KEY_ID=aaa && export AWS_SECRET_ACCESS_KEY=bbb && export AWS_SESSION_TOKEN=ccc
^[[?25h

[remyrylan]

@brianantonelli That's strange, is that on AWS? I'm using iTerm2 as my terminal on macOS and all the output is identical when using process.stderr -- everything works perfectly fine.

[brianantonelli]

No, running this on OSX in Terminal. As soon as I make the call to inquirer I get those control chars. The one at the end really throws me because its printing that many function calls later. I only see these characters in VIM. I caught this because it breaks wrapping the output in a eval $(foo) call.

[SBoudrias]

@brianantonelli weird, but that doesn't seem relate to Inquirer. As you might guess, we're not snooping in on your AWS creds.

[brianantonelli]

That's just an example output from an application that leverages this library. In my application if I pipe all data to stderr using the above solution and only do a single output to stdout (the AWS keys export command in this case) I see these control characters. If I remove the call to inquirer the control chars disappear.

[SBoudrias]

@brianantonelli I'm not super familiar with that, but any chance some ANSI control chars can't be use on stderr?

[brianantonelli]

This only occurs if you use the list prompt. If I do a standard input prompt the characters aren't there. Here's a snippet to reproduce this:

var inquirer = require('inquirer'),
    prompt   = inquirer.createPromptModule({ output: process.stderr });

console.error('start');

if(process.argv[2] === 'inq'){
    prompt([ { type: 'list', name: 'test', message: 'Test', choices: ['a', 'b', 'c'] }]).then(function(answers){
        console.error(answers);
    });
}

console.log('test');
console.error('stop');

• Running node test.js > out.txt && vi out.txt shows no control characters:

test

• Running node test.js inq > out.txt && vi out.txt shows control characters:

^[[?25ltest
^[[?25h^[[?25h

[brianantonelli]

Any ideas?

[popey456963]

@brianantonelli Those control codes are for colours. This is something inquirer uses. Vi doesn't support those control code colours, so displays the base codes. Hence you're running into an issue.

[brianantonelli]

Can't those be disabled?

[popey456963]

@brianantonelli You can use something like strip-ansi to remove ansi from a string, I've opened an issue to be able to use it with streams jlord/sheetsee.js#26. However, it would probably be pretty simple to allow it to support streams yourself.

It's been a while since I've manipulated such streams, but with a stream.Transform it should work.

[SBoudrias]

Simpler yet, I believe chalk doesn't print colors when --no-color is in the process argv.