How to automate editing of static html files?

Question

JavaScript

Hi everybody!
There is such a task. There are many static html files. You need to add prefixes to all css classes in them.
Maybe you will advise online services, utilities or scripts to perform the replacement.

Answer 1

To hell with regular expressions. I solved the problem with posthtml

Answer 2

Probably any IDE will be able to do this with a regular expression autocorrect. Well, here is Atom, for example, from free ones or Sublime there...