VI or VIM editor

VI/VIM is a simple and powerful editor. If you are accessing a remote workstation or cluster where you don't have the option to launch graphical programs, VIM is a great option. Almost any Linux or UNIX system has VI editor preinstalled. Recent OS will likely have VIM (Vi IMproved) instead of classic VI editor. You can check the version of VI by:

vi --version

In case it is not installed in your system, you can install using a package manager:

# ubuntu / debian
apt install vim

• Open/create a file.txt to read and/or write:

vi file.txt

• Go into INSERT mode by (check in the bottom of the window for --INSERT--) by pressing [i].

• Go into REPLACE mode (check in the bottom for --REPLACE--) by pressing [shift] + [r].

• Few other ways to enter the editing mode:

Key binding	Description
a	Append text after the cursor
o	Open a new line below the cursor and enter insert mode
O	Open a new line above the cursor and enter insert mode
I	Insert at the beginning of the current line
A	Append at the end of the current line

• Editing in insert mode

Key bindings	Description
[Ctrl] + w	Delete the word before the cursor
[Ctrl] + u	Delete all text from the cursor position to the beginning of line
[Ctrl] + t	Indent the current line
[Ctrl] + d	Outdent the current line

• Go into readonly/normal mode by pressing [esc].

• To save file, first go into readonly mode ([esc]) and then type:

:w

• To exit vim, first go into readonly mode ([esc]) and then:

:q

• You can combine both to save and exit (keyboard shortcut [Shift]+[z z]):

:wq

• Exit without saving (keyboard shortcut [Shift]+[z q]):

:q!

• Search in the file: Type / followed by the phrase you are looking for. Press n go to the next match ([shift] + n to go back to the previous match). You can search backwards using ?

• See line numbers: :set nu

• Hide line numbers: :set nonu

• Spellcheck: :set spell

• Turn off spellcheck: :set nospell

• Set user spell file: :set spellfile=~/.vim/en.utf-8.add

• Browse files and folders using file explorer: :E

Keyboard shortcuts

Key bindings	Description
G	Go to the end of the file
5G	Go to specific line of the file (here line 5)
5H	Move relative to the top line on the screen
3L	Move relative to the bottom line on the screen
gg	Go to the beginning of file
control + f	Scroll forward one page
control + b	Scroll backward one page
$	Go to the end of line
0	Go to the beginning of line
w	Move one word forward
b	Move one word backward
db	Delete one word backwards
dw	Delete one word forwards
d$ / D	Delete to the end of line
d0	Delete to the beginning of line
dd	Delete a whole line
cc	Clear whole line and enter insert mode
5dd	Delete 5 lines below cursor
dG	Delete all lines below cursor
cG	Clear all lines below cursor and and enter insert mode
dgg	Delete all lines above cursor
cgg	Clear all lines above cursor and and enter insert mode
u	Undo (or type :u; :2u (undo twice))
U	Undo all changes in a line (it is considered as a new change, so we can undo U action with u.)
control + r	Redo
control + l	Redraw/reload
z=	Spelling suggestions
zg	Add new word to the user dictionary
zug	Remove word from the dictionary
.	Repeat last command

• Open two files to compare differences:

vi -d file.txt file_edit.txt

• Move a line up/down: this can be achieved by few key combinations. To move one line above its current position: ddkP. Similarly, to move a line below its current line: ddjP. Detailed explanation of steps:
  • dd to delete current line and put it in default register
  • k or j to move up or down
  • P to paste above current line.

visual mode

Enter Visual mode by pressing v, V or [control] + v for visual character, line or block modes, respectively. Select text using the arrow keys on the key board. You can:

• Press c it will clear the selected part and enter into insert mode.

• To delete multiple lines, press [shift] + v to enter visual line mode, select multiple lines with arrow up/down or j/k keys, finally press d to delete or press c to clear and enter into insert mode.

• Press y to copy (yanked).

• You can paste in another location in VIM by pressing p.

• Press "+y ("*y on macOS) to copy to system clipboard, you can paste in another program using your system shortcut like [command] + v or [control] + v.

• Comment multiple lines:

  • Enter block visual mode: [control] + v
  • Select the lines (first col) using up/down arrow keys
  • Enter insert mode: [shift] + i
  • Type commenting character e.g., #
  • Press [esc].

• Un-comment multiple lines:

  • Enter block visual mode: [control] + v
  • Select the lines (one or multiple columns) using arrow keys
  • Press x followed by [esc].

vimrc

You can customize your vi editor by creating a ~/.vimrc file and saving your settings there. Like:

syntax on
set tabstop=4
set ruler
colorscheme darkblue
set textwidth=80
set cc=81
set autoindent
set spell
hi SpellBad ctermbg=Yellow
hi SpellBad ctermfg=DarkRed
set spellfile=~/.vim/en.utf-8.add

" Syntax highlight for custom filetypes
au BufRead,BufNewFile *.in set filetype=fortran
au BufRead,BufNewFile *.out set filetype=fortran
au BufRead,BufNewFile matplotlibrc set filetype=python

set hlsearch
hi Search ctermbg=LightBlue
hi Search ctermfg=black

• Convert tabs to spaces. Add the following to your .vimrc:

set tabstop=2 shiftwidth=2 expandtab

Convert existing tabs to spaces by :retab (once the above settings are added).

Set different tab width for a specific filetype:

aug python
    " ftype/python.vim overwrites this
    au FileType python setlocal ts=4 sts=4 sw=4 noexpandtab
aug end

Plugins

• Installing vimplug:

curl -fLo ~/.vim/autoload/plug.vim --create-dirs \
    https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim

• Installing plugins using vimplug: add this to your .vimrc

call plug#begin('~/.vim/plugged')
    Plug 'junegunn/goyo.vim'
call plug#end()

Save the file :w. Then install plugins by issuing :PlugInstall.

You can modify or add your own settings to a plugin. For example, if you want to call Limelight along with Goyo. Go to

~/.vim/plugged/goyo.vim/autoload/goyo.vim

and add a line Limelight. You may add other settings, say, set spell etc.

Getting help

You can type for example:

:help gg
:help CTRL-V