Very useful to output a category link with just the slug of a category. Saves lots of hardcoded URL's ending up all over a theme that need to be rebuilt when the permalink structure changes/is changed.

wp_category_link.php

<?php
// Useage: <a href="<?php category_link('prwhiteboard') ?>">PR Whiteboard</a>

if (!function_exists('category_link')) {
	function category_link($slug) {
		$cat = get_category_by_slug($slug);
		$id = $cat->term_id;
		
		// If the theme implements the relative URL filtering provided by the roots
		// starter theme, let's filter the output first so everything is squeaky clean
		if (function_exists('roots_root_relative_url')) {
			echo roots_root_relative_url(get_category_link($id));
		} else {
			echo get_category_link($id);
		}
	}
}