| # arch [![travis][travis-image]][travis-url] [![npm][npm-image]][npm-url] [![downloads][downloads-image]][downloads-url] [![javascript style guide][standard-image]][standard-url] | |
| [travis-image]: https://img.shields.io/travis/feross/arch/master.svg | |
| [travis-url]: https://travis-ci.org/feross/arch | |
| [npm-image]: https://img.shields.io/npm/v/arch.svg | |
| [npm-url]: https://npmjs.org/package/arch | |
| [downloads-image]: https://img.shields.io/npm/dm/arch.svg | |
| [downloads-url]: https://npmjs.org/package/arch | |
| [standard-image]: https://img.shields.io/badge/code_style-standard-brightgreen.svg | |
| [standard-url]: https://standardjs.com | |
| ### Better `os.arch()` for node and the browser -- detect OS architecture | |
| [](https://saucelabs.com/u/arch2) | |
| This module is used by [WebTorrent Desktop](http://webtorrent.io/desktop) to | |
| determine if the user is on a 32-bit vs. 64-bit operating system to offer the | |
| right app installer. | |
| In Node.js, the `os.arch()` method (and `process.arch` property) returns a string | |
| identifying the operating system CPU architecture **for which the Node.js binary | |
| was compiled**. | |
| This is not the same as the **operating system CPU architecture**. For example, | |
| you can run Node.js 32-bit on a 64-bit OS. In that situation, `os.arch()` will | |
| return a misleading 'x86' (32-bit) value, instead of 'x64' (64-bit). | |
| Use this package to get the actual operating system CPU architecture. | |
| **BONUS: This package works in the browser too.** | |
| ## install | |
| ``` | |
| npm install arch | |
| ``` | |
| ## usage | |
| ```js | |
| var arch = require('arch') | |
| console.log(arch()) // always returns 'x64' or 'x86' | |
| ``` | |
| In the browser, there is no spec that defines where this information lives, so we | |
| check all known locations including `navigator.userAgent`, `navigator.platform`, | |
| and `navigator.cpuClass` to make a best guess. | |
| If there is no *affirmative indication* that the architecture is 64-bit, then | |
| 32-bit will be assumed. This makes this package perfect for determining what | |
| installer executable to offer to desktop app users. If there is ambiguity, then | |
| the user will get the 32-bit installer, which will work fine even for a user with | |
| a 64-bit OS. | |
| For reference, `x64` means 64-bit and `x86` means 32-bit. | |
| Here is some history behind these naming conventions: | |
| - https://en.wikipedia.org/wiki/X86 | |
| - https://en.wikipedia.org/wiki/IA-32 | |
| - https://en.wikipedia.org/wiki/X86-64 | |
| ## Node.js proposal - `os.sysarch()` | |
| Note: There is | |
| [a proposal](https://github.com/nodejs/node-v0.x-archive/issues/2862#issuecomment-103942051) | |
| to add this functionality to Node.js as `os.sysarch()`. | |
| ## license | |
| MIT. Copyright (c) [Feross Aboukhadijeh](http://feross.org). | |