README.md
1# cross-spawn
2
3[![NPM version][npm-image]][npm-url] [![Downloads][downloads-image]][npm-url] [![Build Status][travis-image]][travis-url] [![Build status][appveyor-image]][appveyor-url] [![Dependency status][david-dm-image]][david-dm-url] [![Dev Dependency status][david-dm-dev-image]][david-dm-dev-url]
4
5[npm-url]:https://npmjs.org/package/cross-spawn
6[downloads-image]:http://img.shields.io/npm/dm/cross-spawn.svg
7[npm-image]:http://img.shields.io/npm/v/cross-spawn.svg
8[travis-url]:https://travis-ci.org/IndigoUnited/node-cross-spawn
9[travis-image]:http://img.shields.io/travis/IndigoUnited/node-cross-spawn/master.svg
10[appveyor-url]:https://ci.appveyor.com/project/satazor/node-cross-spawn
11[appveyor-image]:https://img.shields.io/appveyor/ci/satazor/node-cross-spawn/master.svg
12[david-dm-url]:https://david-dm.org/IndigoUnited/node-cross-spawn
13[david-dm-image]:https://img.shields.io/david/IndigoUnited/node-cross-spawn.svg
14[david-dm-dev-url]:https://david-dm.org/IndigoUnited/node-cross-spawn#info=devDependencies
15[david-dm-dev-image]:https://img.shields.io/david/dev/IndigoUnited/node-cross-spawn.svg
16
17A cross platform solution to node's spawn and spawnSync.
18
19
20## Installation
21
22`$ npm install cross-spawn`
23
24If you are using `spawnSync` on node 0.10 or older, you will also need to install `spawn-sync`:
25
26`$ npm install spawn-sync`
27
28
29## Why
30
31Node has issues when using spawn on Windows:
32
33- It ignores [PATHEXT](https://github.com/joyent/node/issues/2318)
34- It does not support [shebangs](http://pt.wikipedia.org/wiki/Shebang)
35- No `options.shell` support on node < v6
36- It does not allow you to run `del` or `dir`
37
38All these issues are handled correctly by `cross-spawn`.
39There are some known modules, such as [win-spawn](https://github.com/ForbesLindesay/win-spawn), that try to solve this but they are either broken or provide faulty escaping of shell arguments.
40
41
42## Usage
43
44Exactly the same way as node's [`spawn`](https://nodejs.org/api/child_process.html#child_process_child_process_spawn_command_args_options) or [`spawnSync`](https://nodejs.org/api/child_process.html#child_process_child_process_spawnsync_command_args_options), so it's a drop in replacement.
45
46
47```js
48var spawn = require('cross-spawn');
49
50// Spawn NPM asynchronously
51var child = spawn('npm', ['list', '-g', '-depth', '0'], { stdio: 'inherit' });
52
53// Spawn NPM synchronously
54var results = spawn.sync('npm', ['list', '-g', '-depth', '0'], { stdio: 'inherit' });
55```
56
57
58## Caveats
59
60#### `options.shell` as an alternative to `cross-spawn`
61
62Starting from node v6, `spawn` has a `shell` option that allows you run commands from within a shell. This new option solves most of the problems that `cross-spawn` attempts to solve, but:
63
64- It's not supported in node < v6
65- It has no support for shebangs on Windows
66- You must manually escape the command and arguments which is very error prone, specially when passing user input
67
68If you are using the `shell` option to spawn a command in a cross platform way, consider using `cross-spawn` instead. You have been warned.
69
70
71#### Shebangs
72
73While `cross-spawn` handles shebangs on Windows, its support is limited: e.g.: it doesn't handle arguments after the path, e.g.: `#!/bin/bash -e`.
74
75Remember to always test your code on Windows!
76
77
78## Tests
79
80`$ npm test`
81
82
83## License
84
85Released under the [MIT License](http://www.opensource.org/licenses/mit-license.php).
86
