# common-path-prefix

Computes the longest prefix string that is common to each path, excluding the
base component. Tested with Node 0.10 and above.

## Installation

```
npm install --save common-path-prefix
```

## Usage

The module has one default export, the `commonPathPrefix` function:

```js
var commonPathPrefix = require('common-path-prefix')
```

Call `commonPathPrefix()` with an array of paths (strings) and an optional
separator character:

```js
var paths = ['templates/main.handlebars', 'templates/_partial.handlebars']

commonPathPrefix(paths, '/') // returns 'templates/'
```

If the separator is not provided the first `/` or `\` found in the first path
string is used. This means the module works correctly no matter the platform:

```js
commonPathPrefix(['templates/main.handlebars', 'templates/_partial.handlebars']) // returns 'templates/'
commonPathPrefix(['templates\\main.handlebars', 'templates\\_partial.handlebars']) // returns 'templates\\'
```

You can provide any separator, for example:

```js
commonPathPrefix(['foo$bar', 'foo$baz'], '$') // returns 'foo$''
```

An empty string is returned if no common prefix exists:

```js
commonPathPrefix(['foo/bar', 'baz/qux']) // returns ''
```

Note that the following *does* have a common prefix:

```js
commonPathPrefix(['/foo/bar', '/baz/qux']) // returns '/'
```