# common-path-prefix Computes the longest prefix string that is common to each path, excluding the base component. Tested with Node.js 8 and above. ## Installation ```console npm install common-path-prefix ``` ## Usage The module has one default export, the `commonPathPrefix` function: ```js const commonPathPrefix = require('common-path-prefix') ``` Call `commonPathPrefix()` with an array of paths (strings) and an optional separator character: ```js const paths = ['templates/main.handlebars', 'templates/_partial.handlebars'] commonPathPrefix(paths, '/') // returns 'templates/' ``` If the separator is not provided the first `/` or `\` found in any of the paths is used. Otherwise the platform-default value is used: ```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 '' commonPathPrefix(['foo/bar']) // returns '' ``` Note that the following *does* have a common prefix: ```js commonPathPrefix(['/foo/bar', '/baz/qux']) // returns '/' ```