executive

executive

An elegant child_process.spawn. Automatically pipes stderr and stdout for you in a non-blocking fashion, making it very useful with build tools and task runners. Great async support with easy serial and parallel command execution.

Features

• Node.js callback, Promises and synchronous APIs.
• Serial execution by default, parallel optional.
• Automatically pipes stderr and stdout by default.
• Streams stderr and stdout rather than blocking on command completion.
• Automatically uses shell when command uses operators or globs.
• New-line delimited strings are automatically executed sequentially.

Install

$ npm install executive

Usage

No need to echo as stderr and stdout are piped by default.

var exec = require('executive');

exec('uglifyjs foo.js --compress --mangle > foo.min.js')

It's easy to be quiet too.

exec.quiet('uglifyjs foo.js --compress --mangle > foo.min.js')

Callbacks and promises supported.

exec.quiet('ls -l', function(err, stdout, stderr) {
    var files = stdout.split('\n');
})

{stdout} = yield exec.quiet('ls -l')
var files = stdout.split('\n');

Automatically serializes commands.

exec(['ls', 'ls', 'ls'], function(err, stdout, stderr) {
    // All three ls commands are called in order.
});

exec(`
ls
ls
ls`) // Same;

Want to execute your commands in parallel? No problem.

{stdout} = yield exec.parallel(['ls', 'ls', 'ls'])

Options

Options are passed as the second argument to exec. Helper methods for quiet, interactive, parallel and sync do what you expect.

exec('ls', {options: quiet})

and

exec.quiet('ls')

are equivalent.

options.interactive | exec.interactive

default false

If you need to interact with a program (your favorite text editor for instance) or watch the output of a long running process (tail -f), or just don't care about checking stderr and stdout, set interactive to true:

exec.interactive('vim', function(err) {
    // Edit your commit message and whatnot
});

options.quiet | exec.quiet

default false

If you'd prefer not to pipe stdin, stdout, stderr set quiet to false:

exec.quiet(['ls', 'ls'], function(err, stdout, stderr) {
    // You can still inspect stdout, stderr of course.
});

options.sync | exec.sync

default false

Blocking version of exec. Returns {stdout, stderr} or throws an error.

options.parallel | exec.parallel

default false

Uses parallel rather than serial execution of commands.

options.shell

default null

Force a shell to be used for command execution.

Extra credit

Great with cake, grunt, gulp and other task runners. Even better mixed with generator-based control flow libraries or async/await.

Complex example using shortcake (which provides a superset of cake's features, including generator/promise task support):

require 'shortcake'

task 'package', 'Package project', ->
  yield exec '''
    mkdir -p dist/
    rm   -rf dist/*
  '''

  yield exec.parallel '''
    cp manifest.json dist/
    cp -rf assets/   dist/
    cp -rf lib/      dist/
    cp -rf views/    dist/
  '''

  yield exec '''
    zip -r package.zip dist/
    rm -rf dist/
  '''