Key Mappings in Vim

Introduction#

Updating Vim key mappings allows you to solve two kinds of problems: Re-assigning key commands to letters that are more memorable or accessible, and creating key commands for functions which have none. Here you will learn about the various ways to [re]map key commands, and the context to which they apply (i.e. vim modes)

Basic mapping

map Overview

A key sequence can be re-mapped to another key sequence using one of the map variants.

As an example, the following typical map will exit Insert mode when you press jk in quick sequence:

:inoremap jk <Esc>

map Operator

There are multiple variants of :map for different modes.

Usually, you should use the :noremap variants; it makes the mapping immune to remapping and recursion.

map Command

• You can display all mappings using :map (or one of the variations above).
• To display the current mapping for a specific key sequence, use :map <key> where <key> is a sequence of keys
• Specials keys like Esc are mapped using special <> notation, like <Esc>. For the full list of key codes, see https://vimdoc.sourceforge.net/htmldoc/intro.html#keycodes
• :nmapclear - Clear all normal mode maps
• :nunmap - Unmap a normal mode map
• You can configure the maximum time between keys of a sequence by changing the timeout and ttimeout variables

Examples

• imap jk <Esc>: typing jk in insert mode will bring you back to normal mode
• nnoremap tt :tabnew<CR>: typing tt in normal mode will open a new tab page
• nnoremap <C-j> <C-w>j: typing <C-j> in normal mode will make you jump to the window below and to the left
• vmap <C-c> \cc: typing <C-c> in visual mode will execute \cc (NERDCommenter command to comment the line). As this relies on a plugin mapping, you cannot use :vnoremap here!

futher reading here

Map leader key combination

The leader key could be used as a way to create a mapping with a key-binding that can be overridden by the end user.

The leader is the \ key by default. In order to override it, the end-user would have to execute :let g:mapleader='somekey(s)' before defining the mapping.

In a typical scenario, the mapleader is set in the .vimrc, and plugins use <Leader> in the keybinding part of their mappings to have them customizable.

In the plugin, we would define mappings with:

:nnoremap <Leader>a somecomplexaction

This would map the somecomplexaction action to the \+a key combination.

The a action without the leader does not change.

It’s also possible to use <Plug>Mappings to leave more room to customise plugins keybindings.

Illustration of Basic mapping (Handy shortcuts).

In most text editors, the standard shortcut for saving the current document is Ctrl+S (or Cmd+S on macOS).

Vim doesn’t have this feature by default but this can be mapped to make things easier. Adding the following lines in .vimrc file will do the job.

nnoremap <c-s> :w<CR>
inoremap <c-s> <c-o>:w<CR>

The nnoremap command maps Ctrl+s to :w (write current contents to file) command whereas the inoremap command maps the Ctrl+S to :w command and returns back to the insert mode (<c-o> goes into normal mode for one command and returns to insert mode afterwards, without altering cursor position which other solutions like <esc>:w<cr>a cannot ensure).

Similarly,

" This is commented, as Ctrl+Z is used in terminal emulators to suspend the ongoing program/process.
" nnoremap <c-z> :u<CR>

" Thus, Ctrl+Z can be used in Insert mode
inoremap <c-z> <c-o>:u<CR>

" Enable Ctrl+C for copying selected text in Visual mode
vnoremap <c-c> <c-o>:y<CR>

PS: However it must be noted that Ctrl+S may not work as expected while using ssh (or PuTTY). The solution to this is not within the scope of this document, but can be found Here.