Vim

Apply recorded macro to all opened buffers

:bufdo execute "normal @a" | write

Replace two or more empty lines by one

:%s/\n\{3,}/^M^M/g

To type ^M - press Ctrl + v, Enter

Remove lines that do not contains word

:v/warning/d

Commenting code

Ctrl + -, Ctrl + -

Plugin: https://github.com/tomtom/tcomment_vim

List loaded scripts (plugins)

:sriptnames

Get output of external programm

:read !date

Get output of vim command

:redir @a
:scriptnames
:redir END
"ap

:redir @a - will redirect output to a register, "ap - paste text from register

Pasting text without auto indent

:set past
# insert text
:set nopaste

Or you can bind it to key like this:

set pastetoggle=<F2>