Set split to size of file

Question

I have a file that is 9 lines long called foo.txt . I use

:split foo.txt 

and the new split takes up a full 50% of the editor, which results in a lot of wasted space.

I can resize it with :resize ctrl-R=line('$') but I have to type it manually each time the file changes because the editor only remembers the evaluated value.

So my question is:

• Is it possible to open a split with maximum height to be the size of the file
• Is it possible to have this happen dynamically, so the size of the split changes (to some maximum) as I add and remove lines.

Answer 1

Possibly something like

augroup resizer
  autocmd!
  autocmd TextChanged * execute 'resize' line('$')
  autocmd TextChangedI * execute 'resize' line('$')
augroup end

which should resize the current window as the text is changed (but this may be slow, performance-wise: an alternative would perhaps be TextChanged + InsertLeave).