vim#

Concepts#

Why vim?#

vim (Vi Improved) is the most widely available text editor on Unix/Linux systems. Some form of vi exists on virtually every Linux installation, even minimal server images where nano is not installed. vim is extremely powerful once learned, but has a steep learning curve because it works fundamentally differently from editors you may be used to.

Learning vim is not mandatory for this course — nano is sufficient for editing files. But understanding vim basics will serve you well when you encounter a system where it is the only available editor.

The Key Concept: Modes#

Unlike nano (where you just type), vim has modes. Each mode interprets your keystrokes differently:

Mode Purpose How to Enter
Normal Navigate, delete, copy, paste, run commands Esc (always returns here)
Insert Type text (like a normal editor) i, a, o, I, A, O
Visual Select text v (character), V (line), Ctrl+V (block)
Command Run commands (save, quit, search, replace) : from Normal mode

Normal mode is the default. When you open vim, you are in Normal mode. Your keystrokes are commands, not text. This is the #1 source of confusion for beginners.

The most important rule: When in doubt, press Esc — it always takes you back to Normal mode.

Starting and Quitting vim# 

vim filename.txt               # open a file
vim +15 filename.txt           # open and jump to line 15
vim -R filename.txt            # open in read-only mode

How to Quit#

You don’t. Once vim is opened it will extract a toll from your soul.

From Normal mode (press Esc first):

Command Action
:q Quit (fails if there are unsaved changes)
:q! Quit without saving (force quit)
:w Save (write)
:wq Save and quit
:x Save and quit (same as :wq, slightly shorter)
ZZ Save and quit (shortcut, no : needed)
ZQ Quit without saving (shortcut)

Normal Mode — Navigation#

In Normal mode, you navigate without arrow keys (though arrow keys also work):

Basic Movement#

Key Action
h Left
j Down
k Up
l Right
w Jump forward to start of next word
b Jump backward to start of previous word
e Jump to end of current word
0 Go to beginning of line
$ Go to end of line
^ Go to first non-blank character of line

Larger Movements#

Key Action
gg Go to first line of file
G Go to last line of file
42G or :42 Go to line 42
Ctrl + f Page forward (down)
Ctrl + b Page backward (up)
Ctrl + d Half page down
Ctrl + u Half page up
{ Previous paragraph (empty line)
} Next paragraph

Entering Insert Mode#

From Normal 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 and insert
O Open new line above and insert

Press Esc to return to Normal mode when done typing.

Normal Mode — Editing#

Deleting#

Command Action
x Delete character under cursor
dd Delete entire line
dw Delete from cursor to start of next word
d$ or D Delete from cursor to end of line
d0 Delete from cursor to beginning of line
3dd Delete 3 lines

Copying (Yanking) and Pasting#

Command Action
yy Yank (copy) entire line
yw Yank word
y$ Yank to end of line
3yy Yank 3 lines
p Paste after cursor
P Paste before cursor

Undo and Redo#

Command Action
u Undo
Ctrl + r Redo
. Repeat last command

vim’s Language: Verb + Count + Motion#

vim commands follow a grammar: verb + count (optional) + motion.

Verb Meaning
d Delete
y Yank (copy)
c Change (delete and enter insert mode)
Motion Meaning
w Word
$ End of line
0 Beginning of line
G End of file
gg Beginning of file
} Next paragraph

Examples:

  • d3w — delete 3 words
  • y$ — yank to end of line
  • c2w — change (replace) 2 words
  • dG — delete from cursor to end of file
  • d5j — delete 5 lines down

Search and Replace#

Command Action
/pattern Search forward for “pattern”
?pattern Search backward
n Next match
N Previous match
* Search for word under cursor (forward)
# Search for word under cursor (backward)

Search and Replace# 

:s/old/new/           " Replace first occurrence on current line
:s/old/new/g          " Replace all occurrences on current line
:%s/old/new/g         " Replace all occurrences in file
:%s/old/new/gc        " Replace all with confirmation (y/n each time)
:10,20s/old/new/g     " Replace in lines 10-20

Visual Mode — Selecting Text#

From Normal mode:

Key Action
v Character-wise visual selection
V Line-wise visual selection
Ctrl + v Block (column) visual selection

After selecting, apply an action:

  • d — delete selection
  • y — yank selection
  • > — indent selection
  • < — unindent selection
  • : — apply a command to the selection

Useful Commands#

Command Action
:set number Show line numbers
:set nonumber Hide line numbers
:set paste Paste mode (disables auto-indent)
:set nopaste Exit paste mode
:!command Run a shell command without leaving vim
:r filename Insert the contents of a file
:r !command Insert the output of a command

Basic .vimrc Configuration#

Create ~/.vimrc to customize vim:

" Show line numbers
set number

" Highlight search results
set hlsearch

" Incremental search (highlight as you type)
set incsearch

" Ignore case in search (unless uppercase is used)
set ignorecase
set smartcase

" Tab settings
set tabstop=4
set shiftwidth=4
set expandtab

" Auto-indentation
set autoindent
set smartindent

" Show current mode
set showmode

" Show matching brackets
set showmatch

" Enable syntax highlighting
syntax on

" Enable mouse
set mouse=a

Lab#

Exercise 1: Open, Insert, Save, Quit# 

# Open (or create) a file
vim ~/vim_practice.txt

# You are in Normal mode. Press i to enter Insert mode.
# Type: "This is my first vim edit."
# Press Esc to return to Normal mode.
# Type :wq and press Enter to save and quit.

# Verify
cat ~/vim_practice.txt

Exercise 2: Navigation# 

# Open a large file
vim /etc/services

# Practice Normal mode navigation:
# gg   — go to top of file
# G    — go to bottom of file
# :50  — go to line 50
# w    — move forward by word (do it several times)
# b    — move backward by word
# 0    — go to beginning of line
# $    — go to end of line
# Ctrl+f — page down
# Ctrl+b — page up

# Quit without saving: :q!

Exercise 3: Editing# 

vim ~/vim_practice.txt

# Go to the end of the file: G
# Open a new line below: o
# Type: "Line added with o"
# Esc

# Go to the beginning: gg
# Open a line above: O
# Type: "Line added at the top"
# Esc

# Go to any word, type dw to delete it
# Type u to undo
# Type dd to delete the whole line
# Type u to undo
# Type yy to yank (copy) a line
# Type p to paste it below

# Save and quit: :wq

Exercise 4: Search and Replace# 

vim ~/vim_practice.txt

# Add some content: press o for each new line, Esc between them
# Add these lines:
#   The quick brown fox
#   jumps over the lazy dog
#   The fox is quick

# Search for "fox": /fox then Enter
# Press n to go to next occurrence
# Press N to go back

# Replace "fox" with "cat" everywhere: 
# :%s/fox/cat/gc
# Press y or n for each occurrence

# Save: :w
# Quit: :q

Exercise 5: Visual Mode# 

vim ~/vim_practice.txt

# Move to a line
# Press V to select the whole line (visual line mode)
# Move down with j to select more lines
# Press d to delete the selection
# Press u to undo

# Try character visual mode:
# Press v, move with w or arrow keys to select characters
# Press y to yank (copy) the selection
# Move somewhere and press p to paste

# :wq to save and quit

Exercise 6: Create Your .vimrc# 

vim ~/.vimrc

# Press i for insert mode, then type:
set number
set hlsearch
set incsearch
set ignorecase
set smartcase
set tabstop=4
set shiftwidth=4
set expandtab
set autoindent
set showmode
set showmatch
syntax on

# Esc, then :wq

# Now open any file — you should see line numbers and syntax highlighting
vim ~/vim_practice.txt
# :q to exit

Exercise 7: vim Tutor#

vim includes a built-in tutorial:

vimtutor

This is a 30-minute interactive tutorial. It is the single best way to learn vim. Work through it at your own pace.

Clean Up# 

rm -f ~/vim_practice.txt

Review#

1. What are vim's main modes?

Normal (navigation and commands), Insert (typing text), Visual (selecting text), and Command (: commands for saving, quitting, searching).

2. How do you exit vim without saving?

Press Esc (to ensure you are in Normal mode), then type :q! and press Enter.

3. How do you enter Insert mode?

From Normal mode, press i (insert before cursor), a (append after cursor), or o (open new line below). There are several others (I, A, O). Press Esc to return to Normal mode.

4. How do you delete a line in vim?

In Normal mode, press dd. To delete 5 lines: 5dd.

5. How do you search and replace all occurrences in a file?

:%s/old/new/g — this replaces all occurrences. Add c for confirmation: :%s/old/new/gc.

6. How do you undo and redo in vim?

u to undo, Ctrl + r to redo. Both work in Normal mode.

7. What is the "vim language" for commands?

Commands follow a verb + count + motion pattern. For example: d3w = delete 3 words, y$ = yank to end of line, c2w = change 2 words. This composable grammar makes vim very powerful.

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