cross-var
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[](https://nodei.co/npm/cross-var/) [](https://nodei.co/npm/cross-var/)
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# `cross-var`
[](https://nodei.co/npm/cross-var/)
[](https://nodei.co/npm/cross-var/)
[](https://www.npmjs.com/package/cross-var)
[](https://www.npmjs.com/package/cross-var)
[](https://www.npmjs.com/package/cross-var)
[](https://www.npmjs.com/package/cross-var)
[](http://packagequality.com/#?package=cross-var)
[](http://inch-ci.org/github/elijahmanor/cross-var)
[](https://github.com/elijahmanor/cross-var)
[](https://github.com/elijahmanor/cross-var/fork)
[](https://david-dm.org/elijahmanor/cross-var)
[](https://david-dm.org/elijahmanor/cross-var)
[](https://david-dm.org/elijahmanor/cross-var)
[](https://david-dm.org/elijahmanor/cross-var)
[](https://www.npmjs.com/package/cross-var)
[](https://snyk.io/test/github/elijahmanor/cross-var)
## Overview
When using `npm scripts` it creates a lot of environment variables that are available for you to leverage when executing scripts.
If you'd like to take a look at all of the variables then you can run `npm run env` in your terminal.
```
> npm run env
npm_package_name=cross-var
npm_package_author_name=Elijah Manor
npm_package_version=1.0.0
... lots more ...
```
Now you can use those environment variables in your `npm scripts` by referencing them like the following
```
{
"name": "World",
"scripts": {
"//": "The following only works on Mac OS X/Linux (bash)",
"bash-script": "echo Hello $npm_package_name"
"//": "The following only works on a Windows machine",
"win-script": "echo Hello %npm_package_name%"
}
}
```
```
> npm run bash-script
Hello World
```
However, this won't work on Windows... because it expects the variables to be surrounded by percent signs, so we can change our script just slightly.
### `cross-var` to the Rescue!
The goal of `cross-var` is to let you use one script syntax to work either on a **Mac OS X/Linux (bash)** or **Windows**. Reference the [Usage]() documention below on how to use `cross-var` in your scripts.
## Usage
### Simple Commands
```
{
"version": "1.0.0",
"config": {
"port": "1337"
},
"scripts": {
"prebuild": "cross-var rimraf public/$npm_package_version",
"build:html": "cross-var jade --obj data.json src/index.jade --out public/$npm_package_version/",
"server:create": "cross-var http-server public/$npm_package_version -p $npm_package_config_port",
"server:launch": "cross-var opn http://localhost:$npm_package_config_port"
}
}
```
### Complex Commands
```
{
"version": "1.0.0",
"scripts": {
"build:css": "cross-var \"node-sass src/index.scss | postcss -c .postcssrc.json | cssmin > public/$npm_package_version/index.min.css\"",
"build:js": "cross-var \"mustache data.json src/index.mustache.js | uglifyjs > public/$npm_package_version/index.min.js\"",
}
}
```
## But What About!?!
> Click on one of the following questions to reveal a detailed answer
<details>
<summary>Why don't you use `cross-env`?</summary>
`cross-env` is great for scripts that need a particular environment variable
set, but isn't intended to fix cross-environment issues when using variables
inside an `npm script`
</details>
<details>
<summary>Why don't you use an external node file?</summary>
That is a fine solution to this problem, but if you would rather stick to
straight up `npm scripts`, then this is a good solution
</details>
<details>
<summary>Why don't you just use Windows 10 Ubuntu-based Bash shell?</summary>
Yes, if you can do that... then great! Windows 10’s version 1607 update, dubbed the “Anniversary Update”, has [intergrated a great bash shell](https://msdn.microsoft.com/en-us/commandline/wsl/about) that should allow you to run Linux software directly on Windows without any changes.
However, if you want to support older Windows versions, then you might consider using `cross-env` or another approach to leverage environment variables in your scripts.
</details>