Show Categories on Post

Hi,

I'm trying to pull the category(ies) that the current post is in. The issue I have is that I want the categories to be displayed 'Published in 'Cat 1', 'Cat 2'' where if there is multiple categories it is displayed next to the current with a comma separating. If it has a single category, it doesn't print a comma. Currently, it prints:

Published in 'Cat 1'

Published in 'Cat 2'

My code is below with the template

<?php perch_blog_post_categories(perch_get('s')); ?>

post_category_link.html:

<p>Published in <a href="archive.php?cat=<perch:category id="catSlug" />"><perch:category id="catTitle" /></a></p>

Hope this makes sense.

Thanks,