nvim

Neovim, a programmer's text editor based on Vim, provides several modes for different kinds of text manipulation. Pressing i in normal mode enters insert mode. <Esc> goes back to normal mode, which doesn't allow regular text insertion. See also: vim, vimtutor, vimdiff. More information: https://neovim.io.

nvim path/to/file

<Esc>i

<Esc>yy|dd

<Esc>u

<Esc>/search_pattern<Enter>

<Esc>:%s/regular_expression/replacement/g<Enter>

<Esc>:wq<Enter>

<Esc>:q!<Enter>