How to replace text in many nodes? We're upgrading from Bootstrap 2 to 3. Now I need to replace CSS classes in the body fields of many nodes. This needs to be done in at least 5 sites. What is a good way to replace text in all nodes of a site?

Ideally I'd do it with something like drush replace old_str new_str. Found one thing from 2009 that didn't work at all and then I found drush sar, which didn't do the job either.
The Drush Search and Replace plugin may be of some use

This drush plugin performs a text search &amp; replace on all content and content revisions in all text fields and all custom blocks on a Drupal site.
It does this directly in the database, not by loading, editing and then saving entities, so it is very fast. This also means you should clear the Drupal caches after you run this command.

Hopefully it goes without saying you should give this a dry run before applying it to a live site, how well it works will depend on exactly what data you have in the fields.