Show line numbers:

:set nu

“Unshow” line numbers:

:set nonu

Add show/unshow line numbering in vim (F12 key) Add following to /etc/vimrc

nmap <F12> :set number!<CR>

Current line = .

Insert comment character on current and next 5 lines:

:.,+5s/^/#/g

Change all appearances of from to morf from line 1 to current line:

:1,.s/from/morf/g