How to get the directory part of current URL in JavaScript?

Question

I\'m trying to add a \"back to dir\" button at the top of a web page, which would redirect the user to the same URL, but with no filename in it.

For example, clickin

Answer 1

The following gets directories, including the case where the last character is a slash.

document.URL.replace(/\/[^/]+\/?$/, '');

This effectively states the following (assuming they can be found in this order)

1. \/: Find a "/"
2. [^/]+: Find one or more characters after it that are not "/"
3. \/?: Find an optional "/" after those character(s)
4. $: Find the end of the string

Then remove these by '', so we're left with the directory only.

Again, this assumes there is a slash present marking a directory and that this is not just a URL where the only slashes are within http://.