" Unnamed register, containing the text of the last delete or yank % Current filename # Alternate file name * Clipboard contents (X11: primary selection) + Clipboard contents / Last search pattern : Last command-line . Last inserted text - Last small (less than a line) delete = Explanation ahead

:registers

The = sign

=

system

stdout

#!/usr/bin/ruby print rand(100)

~/ruby/random.rb

<C-r>

=

system

=system('~/ruby/random.rb')

:imap <C-j>d <C-r>=system('~/ruby/random.rb')<CR>

imap

<CR>

<C-j>d

The mini calculator

<C-r>=

<C-r>=5 * 3 + 4<CR>

19