How does Stack Overflow generate its SEO-friendly URLs?

Question

What is a good complete regular expression or some other process that would take the title:

How do you change a title to be part of the URL like Stack

Answer 1

There is a small Ruby on Rails plugin called PermalinkFu, that does this. The escape method does the transformation into a string that is suitable for a URL. Have a look at the code; that method is quite simple.

To remove non-ASCII characters it uses the iconv lib to translate to 'ascii//ignore//translit' from 'utf-8'. Spaces are then turned into dashes, everything is downcased, etc.