knownasilya / cli-width Goto Github PK

Fallback to a default if `process.stdout.getWindowSize` doesn't exist

License: ISC License

JavaScript 100.00%

cli-width's Introduction

cli-width

Get stdout window width, with four fallbacks, tty, output.columns, a custom environment variable and then a default.

Tested against Node v12 to v20. Includes TypeScript types.

Usage

npm install --save cli-width

const cliWidth = require('cli-width');

cliWidth(); // maybe 204 :)

You can also set the CLI_WIDTH environment variable.

If none of the methods are supported, and the environment variable isn't set, the default width value is going to be 0, that can be changed using the configurable options.

API

cliWidth([options])

cliWidth can be configured using an options parameter, the possible properties are:

defaultWidth<number> Defines a default value to be used if none of the methods are available, defaults to 0
output<object> A stream to be used to read width values from, defaults to process.stdout
tty<object> TTY module to try to read width from as a fallback, defaults to require('tty')

Examples

Defining both a default width value and a stream output to try to read from:

const cliWidth = require('cli-width');
const ttys = require('ttys');

cliWidth({
  defaultWidth: 80,
  output: ttys.output,
});

Defines a different tty module to read width from:

const cliWidth = require('cli-width');
const ttys = require('ttys');

cliWidth({
  tty: ttys,
});

Tests

npm install
npm test

Coverage can be generated with npm run coverage.

cli-width's People

Contributors

Stargazers

Watchers

Forkers

bcoe ruyadorno luisvt silicon-beach-labs dineshks1 jacksontian sboudrias

cli-width's Issues

Published package in npmjs.org has coverage report in it

add keywords to package.json

Environment variable fallback to share width with children processes

Hi, as you might know already, inquirer makes use of this library to perform it's work.

I'm running into some issues when displaying an inquirer widget inside a script elevated with windosu because of cli-width.

The problem is that windosu calls the script as a child process, and inside that context cli-width returns 0, which causes some problems in this particular line: https://github.com/SBoudrias/Inquirer.js/blob/master/lib/utils/screen-manager.js#L108.

Invalid regular expression: /.{1,0}/: numbers out of order in {} quantifier.

The issue is fixed if we somehow inherit the cli-width from the parent process in the child process, given that just setting a non-zero default value is not enough since inquirer relies on an accurate number to correctly re-render it's widgets.

I was thinking that cli-width could attempt to read from a custom environment variable, like CLI_WIDTH or something like that before returning a default value.

This approach would allow processes to share their cli-width with their children.

For example:

var child_process = require('child_process');
var cliWidth = require('cli-width');

child_process.spawn('node', [ 'foo.js' ], {
    env: {
        CLI_WIDTH: cliWidth()
    }
});

What do you think about this?

Inquirer.js now accepts input/output options

Hi @knownasilya, while I was playing with Inquirer's new input/output streams options (SBoudrias/Inquirer.js#280) I stumbled upon some problems with cli-width making direct access to the process.stdout stream - As you can see in the file changes from the linked PR, the output stream now can be user defined and not only process.stdout.

Now, I don't want to force any design/api but it would be really nice if the module could accept an object as the function parameter, that let us set the output stream (it can always default to process.stdout) and even defining the defaultWidth value too - I find it quite non-standard the way we define the default value as a property before invoking the function.

Let me know if a PR for these changes is welcome and most importantly, many thanks for all the good work 🏆