--- /dev/null
+# npm-cache-filename
+
+Given a cache folder and url, return the appropriate cache folder.
+
+## USAGE
+
+```javascript
+var cf = require('npm-cache-filename');
+console.log(cf('/tmp/cache', 'https://registry.npmjs.org:1234/foo/bar'));
+// outputs: /tmp/cache/registry.npmjs.org_1234/foo/bar
+```
+
+As a bonus, you can also bind it to a specific root path:
+
+```javascript
+var cf = require('npm-cache-filename');
+var getFile = cf('/tmp/cache');
+
+console.log(getFile('https://registry.npmjs.org:1234/foo/bar'));
+// outputs: /tmp/cache/registry.npmjs.org_1234/foo/bar
+```