LFCS Phase 1 Part 30: Introduction to Text Editors - vi and vim Basics

You can view files, but now you need to edit them. On Linux servers, especially minimal installations and emergency recovery systems, graphical editors aren't available. This is where vi (and its improved version vim) becomes essential. Every Linux system has vi/vim installed by default.

For the LFCS exam, you must know how to use vi/vim. You'll need to edit configuration files, create scripts, and modify system settings. While nano is easier for beginners, vi/vim is ubiquitous and understanding it is a core competency for system administrators.

Why vi/vim?

The Reality of Linux Administration

# You're troubleshooting a server issue via SSH
# The system is in minimal mode, no GUI
# You need to edit /etc/fstab to fix boot issues
# What editor do you use?

$ vi /etc/fstab
# vi is ALWAYS available

Why vi/vim is critical:

• ✅ Installed by default on every Linux/Unix system
• ✅ Works over SSH with minimal bandwidth
• ✅ Works in recovery mode when GUI isn't available
• ✅ Extremely powerful for experienced users
• ✅ Required knowledge for LFCS certification

vi vs vim

$ which vi
/usr/bin/vi

$ which vim
/usr/bin/vim

Differences:

• vi: Original editor from 1976, basic features
• vim: "Vi IMproved" (1991), enhanced with syntax highlighting, undo/redo, plugins

Good news: On modern Linux systems, vi is usually a symlink to vim:

$ ls -l /usr/bin/vi
lrwxrwxrwx. 1 root root 3 Jun 25 2024 /usr/bin/vi -> vim

Understanding vim's Modal Nature

This is the #1 concept to understand: vim is a modal editor.

What Does "Modal" Mean?

Unlike modern editors where you just start typing, vim has different modes for different tasks:

| Mode | Purpose | How to Enter | |------|---------|--------------| | Normal | Navigate and execute commands | Press Esc (default mode when vim opens) | | Insert | Type and edit text | Press i, a, o, O from Normal mode | | Visual | Select text | Press v, V, Ctrl+v from Normal mode | | Command-line | Execute commands (save, quit, search) | Press :, /, ? from Normal mode |

Why Modal Editing?

Traditional editor thinking:

Open file → Type → Save → Close

vim thinking:

Open file (Normal mode)
  ↓
Navigate to location (Normal mode)
  ↓
Enter Insert mode (press i)
  ↓
Type text
  ↓
Exit Insert mode (press Esc)
  ↓
Save and quit (:wq)

Advantage: Your hands never leave the home row. Navigation and commands use regular keys, not arrow keys or mouse.

Getting Started with vim

Opening a File

# Create/edit a file
$ vim myfile.txt

# Edit existing file
$ vim /etc/hosts

# Open at specific line
$ vim +10 myfile.txt

# Open in read-only mode
$ view myfile.txt

What You See When vim Opens

~
~
~
~
~
~
~
"myfile.txt" [New File]

Key observations:

• The ~ characters indicate empty lines
• Status line at bottom shows filename
• Cursor is blinking in top-left
• You're in Normal mode (can't type yet!)

Normal Mode: Navigation

When vim opens, you're in Normal mode. This is for navigation and commands, not typing.

Basic Movement (The Arrow Keys Alternative)

Instead of arrow keys, vim uses:

    k (up)
    ↑
h ← ↓ → l
    j (down)

Why h, j, k, l?

• They're on the home row (faster than reaching for arrows)
• Historical: Vi was created on a keyboard without arrow keys

Practice:

$ vim practice.txt
# Press h, j, k, l to move around
# Notice cursor movement

Word-Based Movement

w = move forward one word
b = move backward one word
e = move to end of current word

Example:

The quick brown fox jumps over the lazy dog
^
Cursor here

Press w → moves to "quick"
Press w → moves to "brown"
Press b → moves back to "quick"
Press e → moves to end of "quick"

Line-Based Movement

0 = move to beginning of line
^ = move to first non-whitespace character
$ = move to end of line

File-Based Movement

gg = go to first line
G  = go to last line
10G = go to line 10

Insert Mode: Actually Typing Text

Entering Insert Mode

From Normal mode, press one of these keys:

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

Your First Edit

$ vim myfile.txt
# You're in Normal mode
# Press i to enter Insert mode
# Notice bottom shows: -- INSERT --
# Type: Hello World
# Press Esc to return to Normal mode

What you'll see:

Hello World
~
~
-- INSERT --

Exiting Insert Mode

Always press Esc to return to Normal mode.

This is the most important key in vim. Your workflow:

Normal mode → i (enter Insert) → type text → Esc (back to Normal)

Saving and Quitting

All save/quit commands are executed from Command-line mode (start with :).

Basic Save and Quit Commands

From Normal mode (press Esc first if in Insert mode):

:w         Write (save) file
:q         Quit vim
:wq        Write and quit
:q!        Quit without saving (discard changes)
:wq!       Force write and quit

Step-by-Step: Edit and Save a File

$ vim test.txt

# 1. Press i to enter Insert mode
# 2. Type: This is a test file
# 3. Press Esc to return to Normal mode
# 4. Type: :w (you'll see it at the bottom)
# 5. Press Enter
# Result: "test.txt" [New] 1L, 21C written

# 6. Type: :q
# 7. Press Enter
# Result: vim closes

Common Scenarios

Made changes and want to save:

:w

Made changes and want to save and quit:

:wq

Made mistakes and want to quit without saving:

:q!

vim won't let you quit:

E37: No write since last change (add ! to override)

Solution: Either save (:w) or force quit (:q!)

Basic Editing Commands

All of these work in Normal mode.

Deleting Text

| Command | Action | |---------|--------| | x | Delete character under cursor | | X | Delete character before cursor | | dd | Delete entire line | | dw | Delete word | | d$ | Delete from cursor to end of line | | d0 | Delete from cursor to beginning of line |

Examples:

# Original text:
The quick brown fox

# Cursor on 'q' in "quick"
# Press x → deletes 'q'
The uick brown fox

# Press dd → deletes entire line
(line disappears)

Undo and Redo

u       = Undo last change
Ctrl+r  = Redo (undo the undo)

Practice:

$ vim test.txt
# Type some text in Insert mode
# Press Esc to Normal mode
# Press dd to delete line
# Press u to undo (line comes back)
# Press Ctrl+r to redo (line disappears again)

Copy (Yank) and Paste

In vim terminology:

• Copy = Yank (y)
• Paste = Put (p)

| Command | Action | |---------|--------| | yy | Yank (copy) entire line | | yw | Yank word | | p | Put (paste) after cursor | | P | Put (paste) before cursor |

Example workflow:

Line 1: Important text
Line 2: Other stuff

# Move cursor to Line 1
# Press yy (yanks the line)
# Move cursor to Line 2
# Press p (pastes below Line 2)

Result:
Line 1: Important text
Line 2: Other stuff
Line 1: Important text

Deleting Multiple Lines

3dd = Delete 3 lines
5dd = Delete 5 lines

How it works: Number + command

d   = delete
dd  = delete line
3dd = delete 3 lines

Same pattern works for yank:

3yy = Yank 3 lines

Searching Text

Forward Search

From Normal mode:

/pattern

Example:

# In vim with this text:
The quick brown fox
jumps over the lazy dog

# Press: /fox
# Press Enter
# Cursor jumps to "fox"

# Press n to find next occurrence
# Press N to find previous occurrence

Backward Search

?pattern

Searches backward from cursor position.

Search Navigation

n = Next match (in same direction)
N = Previous match (opposite direction)

Find and Replace

Replace Single Character

r = Replace character under cursor

Example:

Word: cat
Cursor on 'c'
Press: rb
Result: bat

Find and Replace (Substitute)

Syntax:

: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 entire file
:%s/old/new/gc     Replace all with confirmation

Examples:

# Replace "cat" with "dog" on current line
:s/cat/dog/

# Replace all "cat" with "dog" in entire file
:%s/cat/dog/g

# Replace with confirmation (asks yes/no for each)
:%s/cat/dog/gc

Visual Mode: Selecting Text

Entering Visual Mode

From Normal mode:

v       = Character-wise visual mode
V       = Line-wise visual mode
Ctrl+v  = Block visual mode

Visual Mode Workflow

1. Enter visual mode (press v)
2. Move cursor to extend selection
3. Perform operation (d, y, etc.)

Example:

The quick brown fox

# Move cursor to 'q' in "quick"
# Press v (enter visual mode)
# Press w w (select "quick brown")
# Press d (delete selection)

Result:
The fox

Line Numbers

Show Line Numbers

:set number

Shorthand:

:se nu

Hide Line Numbers

:set nonumber

What you see:

  1 Line one
  2 Line two
  3 Line three

Jump to Specific Line

:10         Go to line 10
10G         Go to line 10 (from Normal mode)

vimtutor: The Best Way to Learn

vim comes with an interactive tutorial.

Starting vimtutor

$ vimtutor

What you get:

===============================================================================
=    W e l c o m e   t o   t h e   V I M   T u t o r    -    Version 1.7    =
===============================================================================
     Vim is a very powerful editor that has many commands, too many to
     explain in a tutor such as this.  This tutor is designed to describe
     enough of the commands that you will be able to easily use Vim as
     an all-purpose editor.

     The approximate time required to complete the tutor is 30 minutes,
     depending upon how much time is spent with experimentation.

Why vimtutor is excellent:

• ✅ Interactive (you actually practice on the file)
• ✅ Safe (it's a copy, can't break anything)
• ✅ Comprehensive (covers all basics)
• ✅ Takes ~30 minutes
• ✅ Best way to build muscle memory

Essential vim Commands Quick Reference

Navigation

h, j, k, l    # Left, Down, Up, Right
w             # Forward one word
b             # Backward one word
0             # Beginning of line
$             # End of line
gg            # First line of file
G             # Last line of file
10G           # Go to line 10

Modes

i             # Insert before cursor
a             # Insert after cursor
o             # Open line below
O             # Open line above
Esc           # Return to Normal mode
v             # Visual mode
V             # Visual line mode

Editing

x             # Delete character
dd            # Delete line
3dd           # Delete 3 lines
dw            # Delete word
d$            # Delete to end of line
yy            # Yank (copy) line
3yy           # Yank 3 lines
p             # Paste after cursor
P             # Paste before cursor
u             # Undo
Ctrl+r        # Redo
r             # Replace single character

Search and Replace

/pattern      # Search forward
?pattern      # Search backward
n             # Next match
N             # Previous match
:s/old/new/   # Replace on current line
:%s/old/new/g # Replace in entire file

Save and Quit

:w            # Write (save)
:q            # Quit
:wq           # Write and quit
:q!           # Quit without saving
:wq!          # Force write and quit

Settings

:set number   # Show line numbers
:set nonumber # Hide line numbers

Installing vim

vim comes pre-installed on most Linux distributions. If not:

RedHat/CentOS/Rocky/AlmaLinux

$ sudo dnf install vim

Debian/Ubuntu

$ sudo apt install vim

Check Installation

$ which vim
/usr/bin/vim

$ vim --version
VIM - Vi IMproved 8.2

Common Beginner Mistakes

1. Typing Immediately When vim Opens

Symptom: You type "hello" and strange things happen (h moves cursor left, e moves to end of word, etc.)

Solution: vim opens in Normal mode. Press i first!

2. Can't Exit vim

Symptom: You're stuck in vim and can't get out!

Solution:

1. Press Esc (ensure you're in Normal mode)
2. Type :q!
3. Press Enter

3. Made Changes and vim Won't Quit

Symptom:

E37: No write since last change (add ! to override)

Solution:

• Save then quit: :wq
• Discard changes: :q!

4. Accidentally Entered Replace Mode

Symptom: Everything you type overwrites existing text

Cause: You pressed R (Replace mode)

Solution: Press Esc to return to Normal mode

5. vim Is Beeping or Flashing

Cause: You're trying invalid commands (like pressing Esc repeatedly in Normal mode)

Solution: Just press Esc once and continue

🧪 Practice Labs

Lab 1: Opening and Quitting vim (Beginner)

Task: Open vim, then quit without making changes.

$ vim

# You're now in vim
# Press: :q
# Press Enter
# vim closes

Lab 2: Create and Save a File (Beginner)

Task: Create a file called hello.txt with the text "Hello World" and save it.

$ vim hello.txt

# 1. Press i to enter Insert mode
# 2. Type: Hello World
# 3. Press Esc to return to Normal mode
# 4. Type: :wq
# 5. Press Enter

# Verify the file was created
$ cat hello.txt
Hello World

Lab 3: Edit Existing File (Beginner)

Task: Open hello.txt, add a second line "Welcome to vim", and save.

$ vim hello.txt

# File opens with "Hello World"
# 1. Press o to open new line below
# 2. Type: Welcome to vim
# 3. Press Esc
# 4. Type: :wq
# 5. Press Enter

# Verify
$ cat hello.txt
Hello World
Welcome to vim

Lab 4: Navigate with hjkl (Beginner)

Task: Create a file with 5 lines and practice navigating using h, j, k, l.

$ vim navigation.txt

# Press i and type:
Line 1
Line 2
Line 3
Line 4
Line 5

# Press Esc
# Press gg (go to first line)
# Press j j j (move down 3 lines to Line 4)
# Press k k (move up 2 lines to Line 2)
# Press l l (move right 2 characters)
# Press h (move left 1 character)

# Save and quit: :wq

Lab 5: Delete Lines (Beginner)

Task: Create a file with 5 lines, delete line 3, then save.

$ vim delete.txt

# Press i and type 5 lines
Line 1
Line 2
Line 3
Line 4
Line 5

# Press Esc
# Press gg to go to first line
# Press j j to go to line 3
# Press dd to delete line 3
# Result: Line 3 disappears

# Save: :wq

Lab 6: Undo and Redo (Beginner)

Task: Delete a line, undo it, then redo the deletion.

$ vim undo.txt

# Create some text
# Press i
This line will be deleted
This line stays

# Press Esc
# Move to first line (gg)
# Press dd (deletes "This line will be deleted")
# Press u (undo - line comes back)
# Press Ctrl+r (redo - line disappears again)

# Quit without saving: :q!

Lab 7: Copy and Paste Lines (Intermediate)

Task: Copy line 1 and paste it after line 3.

$ vim copy.txt

# Press i and create:
Line 1: Important
Line 2: Regular
Line 3: Last

# Press Esc
# Press gg (go to line 1)
# Press yy (yank/copy line 1)
# Press 3G (go to line 3)
# Press p (paste below line 3)

# Result:
Line 1: Important
Line 2: Regular
Line 3: Last
Line 1: Important

# Save: :wq

Lab 8: Search Text (Intermediate)

Task: Create a file with multiple occurrences of "test" and practice searching.

$ vim search.txt

# Press i and type:
This is a test file
Another test here
Final test at end

# Press Esc
# Press gg (go to beginning)
# Type: /test
# Press Enter (cursor jumps to first "test")
# Press n (jumps to next "test")
# Press n (jumps to next "test")
# Press N (jumps back to previous "test")

# Quit: :q!

Lab 9: Find and Replace (Intermediate)

Task: Replace all occurrences of "old" with "new" in a file.

$ vim replace.txt

# Press i and type:
This is old text
Another old word
The old way

# Press Esc
# Type: :%s/old/new/g
# Press Enter

# Result:
This is new text
Another new word
The new way

# Save: :wq

Lab 10: Line Numbers (Intermediate)

Task: Enable line numbers, jump to line 5, then disable line numbers.

$ vim numbers.txt

# Create several lines of text
# Press Esc
# Type: :set number
# Press Enter (line numbers appear on left)

  1 Line one
  2 Line two
  3 Line three
  4 Line four
  5 Line five

# Type: :5 (or 5G)
# Press Enter (cursor jumps to line 5)

# Type: :set nonumber
# Press Enter (line numbers disappear)

# Quit: :q!

Lab 11: Insert at Beginning/End of Line (Intermediate)

Task: Practice using I and A to insert at line boundaries.

$ vim insert.txt

# Press i and type:
  This is centered text

# Press Esc
# Press I (capital i - inserts at beginning of line)
# Type: START:
# Press Esc

# Result:
START:  This is centered text

# Press A (inserts at end of line)
# Type:  :END
# Press Esc

# Result:
START:  This is centered text :END

# Quit: :q!

Lab 12: Delete Multiple Lines (Intermediate)

Task: Create 10 lines and delete lines 3-5 (3 lines total).

$ vim multidelete.txt

# Create 10 lines
# Press Esc
# Go to line 3: 3G
# Delete 3 lines: 3dd

# Lines 3, 4, 5 are now deleted
# Remaining lines renumber automatically

# Quit: :q!

Lab 13: Visual Mode Selection (Intermediate)

Task: Use visual mode to select and delete a block of text.

$ vim visual.txt

# Press i and type:
Keep this line
Delete this
And this
And this too
Keep this line

# Press Esc
# Move to "Delete this" line
# Press V (capital v - line visual mode)
# Press j j (select 3 lines)
# Press d (delete selection)

# Result:
Keep this line
Keep this line

# Quit: :q!

Lab 14: Word Navigation (Advanced)

Task: Practice navigating by words using w, b, and e.

$ vim words.txt

# Press i and type:
The quick brown fox jumps over the lazy dog

# Press Esc
# Press 0 (go to beginning of line)
# Press w (cursor moves to "quick")
# Press w (cursor moves to "brown")
# Press w (cursor moves to "fox")
# Press b (cursor moves back to "brown")
# Press e (cursor moves to end of "brown" - the 'n')
# Press $ (cursor moves to end of line)
# Press 0 (cursor moves to beginning of line)

# Quit: :q!

Lab 15: Replace Character (Advanced)

Task: Use r to fix typos without entering Insert mode.

$ vim replace.txt

# Press i and type:
The cxt is on the mxt

# Press Esc
# Move cursor to 'x' in "cxt"
# Press: ra (replaces 'x' with 'a')
# Result: The cat is on the mxt

# Move cursor to 'x' in "mxt"
# Press: ra
# Result: The cat is on the mat

# Save: :wq

Lab 16: Combine Commands (Advanced)

Task: Delete from cursor to end of line using d$.

$ vim combine.txt

# Press i and type:
Keep this part but delete the rest of this line

# Press Esc
# Move cursor to 'b' in "but"
# Press: d$ (delete from cursor to end of line)

# Result:
Keep this part

# Quit: :q!

Lab 17: Edit System File with sudo (Advanced)

Task: Edit /etc/hosts using vim with sudo (read-only without sudo).

# Try without sudo (read-only)
$ vim /etc/hosts
# Notice: "readonly" in status line

# Quit: :q!

# Edit with sudo
$ sudo vim /etc/hosts

# Add a comment
# Press i
# Add line: # Test comment
# Press Esc
# Save: :wq

# Verify
$ sudo tail -1 /etc/hosts
# Test comment

Lab 18: Open File at Specific Line (Advanced)

Task: Open a file directly at line 10.

# Create a file with 20 lines
$ seq 1 20 > numbers.txt

# Open at line 10
$ vim +10 numbers.txt

# vim opens with cursor on line 10
# Notice cursor is on "10"

# Quit: :q!

Lab 19: vimtutor Practice (Advanced)

Task: Complete at least Lesson 1 of vimtutor.

$ vimtutor

# Follow the interactive tutorial
# Lesson 1 teaches:
# - h, j, k, l movement
# - :q! to quit
# - x to delete character
# - i to insert
# - A to append at end of line

# Complete at least Lesson 1 (takes ~5 minutes)
# Quit vimtutor when done: :q!

Lab 20: Create a Multi-Line Document (Advanced)

Task: Create a complete document using various vim techniques.

$ vim document.txt

# Press i and create:
LINUX SYSTEM ADMINISTRATION
---------------------------

Date: 2025-12-08
Author: Your Name

Introduction:
This document covers basic system administration tasks.

Topics:
1. File management
2. User management
3. Network configuration

Conclusion:
Practice makes perfect!

# Press Esc
# Enable line numbers: :set number
# Go to line 1: gg
# Copy title: yy
# Go to end: G
# Paste below: p
# Delete last line: dd
# Find "management": /management
# Press n to find next occurrence
# Replace all "management" with "admin": :%s/management/admin/g
# Save: :wq

# View result
$ cat document.txt

🎯 Key Takeaways

Esc → :q! → Enter

🚀 What's Next?

Coming Up Next:

• Post 31: Advanced vim Techniques (buffers, windows, marks)
• Post 32: Introduction to Text Processing (grep, cut, sort)