vimgrep: Search from 'tags' file location

Question

Is there a simple way to setup a binding that will :vimgrep up until a tags file is found?

I'm curious because I can do set tags=tags;/ to do a similar search to define tags, but am not quite sure how to transfer this to a different use case.

Answer 1

I believe you're looking for a function that will return the directory where the tags file is located, by performing the same kind of lookup up the tree.

You can use findfile() or finddir() for this purpose, both will use a lookup method similar to the one used in the 'tags' option. See :help file-searching for more details on file searching syntax and a more complete list of functions and options that support that syntax.

For example, you can find the tags file up the tree using:

:echo findfile('tags', '.;')

You can get the path to the directory where the tags file using fnamemodify():

:echo fnamemodify(findfile('tags', '.;'), ':p:h')

And you can use that expression to execute a :vimgrep starting on that directory. You'll need :execute to build the command from a string:

:execute 'vimgrep /something/ '
    \ . fnamemodify(findfile('tags', '.;'), ':p:h')
    \ . '/**'

You can easily adapt that to write a function or user-defined command starting the search at the expected directory.

UPDATE: In order to bind a key combination to searching from the directory where your tags file is, you can either use :execute or create an <expr> mapping.

For example:

nnoremap <Leader>s
    \ :execute "vimgrep /"
    \ . escape(input('/'), '/') . "/ "
    \ . fnamemodify(findfile('tags', '.;'), ':p:h') 
    \ . "/**"<CR>

The final <CR> executes the Ex command right away. Input is being escaped so that / characters are allowed.

An alternative, using <expr>, would be:

nnoremap <expr> <Leader>s
    \ ":vimgrep /" . escape(input('/'), '/') . "/ "
    \ . fnamemodify(findfile('tags', '.;'), ':p:h') 
    \ . "/**\<CR>"

This time we're using a string with : so it enters Ex mode first. We're also including the final <CR> inside the string with a "\<CR>" (using "\r" would also be possible, it's equivalent.)

Either approach would do what you want.

UPDATE 2: If you're interested in searching relative to where you found the tags file in specific, then consider using the tagfiles() function to get the path of the one you're using.

Something like this would work:

nnoremap <Leader>s
    \ :execute "vimgrep /"
    \ . escape(input('/'), '/') . "/ "
    \ . fnamemodify(tagfiles()[0], ':p:h') 
    \ . "/**"<CR>