VIM

cat <<'EOF' > /etc/vim/vimrc.local
" Prevent the defaults from being loaded again later, if the user doesn't
" have a local vimrc (~/.vimrc)
let skip_defaults_vim = 1

" Set more options (overwrites settings from /usr/share/vim/vim80/defaults.vim)
" Add as many options as you wish
" Set the mouse mode to 'r'
if has('mouse')
  set mouse=r
endif

" Toggle paste/nopaste automatically when copy/paste with right click in insert mode:
let &t_SI .= "\<Esc>[?2004h"
let &t_EI .= "\<Esc>[?2004l"

inoremap <special> <expr> <Esc>[200~ XTermPasteBegin()

function! XTermPasteBegin()
  set pastetoggle=<Esc>[201~
  set paste
  return ""
endfunction
EOF

Commands:

Add string to the beginning of each line:

:%s/^/string/

Add string to the end of each line:

:%s/$/\string/g

Delete all text:

:%d