To use tags, you must first install ctags or exuberant-ctags. They are in the repositories. To run it, go to the root of your source tree and type:
ctags -R *
That recursively scans the code and produces a database of function definitions, known as tags. It outputs a single file called “tags” into the directory.
Then, in your ~/.vimrc, add:
That line causes vim to search for the file named tags in the current directory and a few levels of parent directory.
To read code using tags, move the cursor to a function call. Press Ctrl-]. That takes you to the definition, and also pushes your current location onto the “tag stack”.
To back out of the definition, press Cntr-o.
That’s most of what you need to know.