vim与领导者一起使用<C-?>

Question

I found this snippet from unite.vim

nnoremap <leader>t :<C-r>Unite -no-split -buffer-name=files   -start-insert file_rec<cr>

It seems it try to map "\\t" to "Unite -no-split -buffer-name=files -start-insert file_rec"

what does <Cr> mean here ? what is the difference from the following:

nnoremap <leader>t :Unite -no-split -buffer-name=files   -start-insert file_rec<cr>

Answer 1

In Ex mode, Ctrl + R (written <Cr> in Vim) will insert the content of the specified register on the Ex command line. <Cr>U will insert the content of the U register. All commands starting with : are Ex mode commands.

To see this in action, do the following:

1. Delete a word using "adw . This means "delete a word to register a ".
2. Enter normal mode.
3. Type in :<Cr>a . Your Ex mode command line will now contain the word.

I have looked at the relevant .vimrc and the unite.vim source, and I doubt the <Cr> is supposed to be there. It is most likely a bug or a typo.

For more information, see :help c_CTRL-R .