How to programmatically create/update a TAGS file with emacs?

Question

Is there any plugin for emacs to automatically update the TAGS file in my C project (for example on buffer save or access) or create a new one if there is no TAGS file present?

Answer 1

etags-update may help in your case. I didn't test it, but according to the readme:

etags-update.el is a Emacs global minor mode that updates your TAGS when saving a file.

I found it on the Emacswiki page for building TAGS files