Readline

Reads line from a terminal, executes them.
Can be configured to use vi keybindings.

Documentation

man readline

https://linux.die.net/man/3/readline

Locations

~/.inputrc

configuration file

inputrc

set editing-mode vi
set keymap vi

# meta+(hjkl) jumps into normal mode from insert mode
set keymap vi-insert
  M-h: vi-movement-mode
  M-j: vi-movement-mode
  M-k: vi-movement-mode
  M-l: vi-movement-mode
  C-l: clear-screen
 
# meta+(hjkl) from normal mode also moves characters
set keymap vi-move
  M-h: previous-char
  M-j: previous-history
  M-k: next-history
  M-l: next-char
  C-l: clear-screen