Can I load different tags per project?

Question

I'm interested in using exuberant-tags (ctags) in vim, but I use Vim for all sorts of projects so I need multiple tag files and I need vim to use the correct tag file on a per project basis.

Is there an easy way to manage this?

e.g. I could store tags in files like ~/.vim/tagfiles/-var-www-mywebsite.com then if I was editing a file in /var/www/mywebsite.com/foo/bar/baz.php it could try looking for

~/.vim/tagfiles/-var-www-mywebsite.com-foo-bar
then
~/.vim/tagfiles/-var-www-mywebsite.com-foo
then
~/.vim/tagfiles/-var-www-mywebsite.com

until it finds a match? But I don't want to reinvent the wheel and spending hours with vimscript if someone's already done it, as I suspect it's a common requirement?

Answer 1

If each project is a separate git repo, one can use fugitive.vim which will automatically point tags at .git/tags, allowing easy per-project tags.

Answer 2

This line should be enough:

set tags=./tags;,tags;

It tells Vim to look for a tags file in the directory of the current file as well as in the working directory, and up, and up, and…

Answer 3

You can use my project-tags plugin for this. It requires a tiny bit more setup than the fugitive.vim approach, but it is also more of a power user tool. Once you set it up for your projects, it will automatically generate tags for you in your projects and it will automatically select the correct tags file for you. It is largely designed around avoiding false positives when the tags file is used for auto-completion or jump to. It uses the following techniques to reduce the number of false positives:

• tags are generated per project, instead of having a global tags file
• tags are also separated per language instead of one tags file for the entire project
• An optional configuration option allows you to specifically exclude certain directories from being used to generate tags. If you tend to get a lot of false positives from code inside a specific directory, excluding it might improve your tags experience.
• An optional configuration option allows you to specifically include a directory outside your project that your project tags file will also have tags from. This is useful when you reference a library that is not inside your project directory. It can also be helpful when used in combination with the exclude option. You can generate tags inside the excluded directory that include the tags from the rest of the project. That way when you are browsing / working with code inside the excluded directory, the tags will still be there and work properly.