✏️ Vim

"Vim is hard at first, but once you learn the basics, you'll love it."

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Cheat Sheet

📑 Table of Contents

• 🎯 Introduction
• 🔄 Vim Modes
• ✍️ Entering Insert Mode
• ⌨️ Command Mode Basics
• 💾 Last-Line Mode (Saving & Quitting)
• 🔍 Searching & Replacing
• ↩️ Undo & Redo
• ✂️ Cut, Copy & Paste
• 🧭 Navigation
• 📂 Working with Multiple Files
• ⚙️ Settings & Configuration
• 📚 Quick Reference Card

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🎯 Introduction

Vim is a powerful, lightweight terminal text editor available on virtually every Linux system. It's very worth learning for DevOps work.

# Install vim
sudo apt install vim

# Open or create a file
vim filename.txt

# Learn vim interactively
vimtutor

💡 Tip: Run vimtutor for an interactive tutorial built into vim.

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🔄 Vim Modes

Vim operates in three main modes:

Mode	Purpose	How to Enter
Command	Navigate, delete, copy, paste	Esc (default mode)
Insert	Type and edit text freely	i, a, o, etc.
Last-Line	Save, quit, search, settings	: (colon)

When you open a file, you start in Command Mode.

┌─────────────────────────────────────────────┐
│                                             │
│              COMMAND MODE                   │
│           (default on open)                 │
│                                             │
│      i, a, o, etc.          :               │
│           ↓                  ↓              │
│    ┌──────────────┐   ┌──────────────┐      │
│    │ INSERT MODE  │   │ LAST-LINE    │      │
│    │  (editing)   │   │   MODE       │      │
│    └──────────────┘   └──────────────┘      │
│           ↑                  ↑              │
│          Esc               Esc              │
│                                             │
└─────────────────────────────────────────────┘

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✍️ Entering Insert Mode

From Command Mode, use these keys to enter Insert Mode:

Key	Action
i	Insert before cursor
I	Insert at beginning of line
a	Append after cursor
A	Append at end of line
o	Open new line below
O	Open new line above

Press Esc to return to Command Mode.

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⌨️ Command Mode Basics

These commands work in Command Mode (press Esc first):

Character Operations

Key	Action
x	Delete character under cursor
r	Replace character under cursor

Movement

Key	Action
h	Move left
j	Move down
k	Move up
l	Move right
w	Jump to next word
b	Jump to previous word
0	Jump to beginning of line
$	Jump to end of line

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💾 Last-Line Mode (Saving & Quitting)

Press : to enter Last-Line Mode, then type a command:

Command	Action
:w	Save (write) file
:q	Quit (fails if unsaved changes)
:q!	Quit without saving (force)
:wq	Save and quit
ZZ	Save and quit (from Command Mode)
:x	Save and quit (only writes if changed)

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🔍 Searching & Replacing

Searching

Command	Action
/pattern	Search forward
?pattern	Search backward
n	Next match
N	Previous match

Search & Replace

:%s/old/new/g

Part	Meaning
%	Apply to all lines
s	Substitute command
old	Pattern to find
new	Replacement text
g	Global (all occurrences per line)

:%s/foo/bar/g      " Replace all 'foo' with 'bar'
:%s/foo/bar/gc     " Replace with confirmation
:s/foo/bar/g       " Replace only on current line

Run External Commands

:!ls               " Run ls command
:!pwd              " Show current directory

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↩️ Undo & Redo

Command	Action
u	Undo last change
Ctrl + r	Redo last undone change
:e!	Revert to last saved version

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✂️ Cut, Copy & Paste

Quick Cut & Paste

Command	Action
dd	Cut (delete) current line
5dd	Cut 5 lines
10dd	Cut 10 lines
yy	Copy (yank) current line
5yy	Copy 5 lines
p	Paste below cursor
P	Paste above cursor

Visual Selection

Command	Action
v	Start character selection
V	Start line selection
Ctrl + v	Start block (column) selection

After selecting:

• y — Copy (yank) selection
• d — Cut (delete) selection
• p — Paste

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🧭 Navigation

Moving Within File

Command	Action
gg	Go to beginning of file
G	Go to end of file
:100	Go to line 100
Ctrl + f	Page down
Ctrl + b	Page up

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📂 Working with Multiple Files

Opening Multiple Files

vim file_a file_b           # Open files in sequence
vim -o file_a file_b        # Open in horizontal split
vim -O file_a file_b        # Open in vertical split
vim -d file_a file_b        # Open in diff mode (vimdiff)

Navigating Between Files

Command	Action
:n or :next	Go to next file
:N or :prev	Go to previous file
:ls	List open buffers

Comparing Files (Diff Mode)

vim -d file_a file_b
# or
vimdiff file_a file_b

Highlights differences between files — useful for comparing configs or code.

⚠️ Warning: If vim closes unexpectedly (crash, terminal closed), a swap file (.swp) is created. You'll see a recovery prompt next time you open the file. Always exit vim properly with :wq or :q!.

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⚙️ Settings & Configuration

Temporary Settings (Current Session)

Command	Action
:set nu	Show line numbers
:set nonu	Hide line numbers
:syntax on	Enable syntax highlighting
:syntax off	Disable syntax highlighting

Permanent Settings

Edit ~/.vimrc in your home directory to set global vim settings:

" ~/.vimrc example
set number          " Show line numbers
syntax on           " Enable syntax highlighting
set tabstop=4       " Tab width
set expandtab       " Use spaces instead of tabs
set autoindent      " Auto-indent new lines

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📚 Quick Reference Card

Mode Switching

Esc             → Command Mode
i, a, o         → Insert Mode
:               → Last-Line Mode

Essential Commands

:w              → Save
:q              → Quit
:wq or ZZ       → Save and quit
:q!             → Quit without saving

Navigation

h j k l         → Left, down, up, right
gg              → Beginning of file
G               → End of file
:100            → Go to line 100

Editing

i               → Insert before cursor
a               → Append after cursor
o               → New line below
x               → Delete character
dd              → Delete line
yy              → Copy line
p               → Paste
u               → Undo
Ctrl + r        → Redo

Search & Replace

/pattern        → Search forward
?pattern        → Search backward
n / N           → Next / previous match
:%s/old/new/g   → Replace all

Multiple Files

:n              → Next file
:N              → Previous file
vim -d a b      → Diff mode

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📝 Note: Vim has a steep learning curve, but mastering even the basics will make you significantly more productive. Run vimtutor for interactive practice!