Lesson 4: Text Editors

Goal: Learn to edit files directly in the terminal with nano and vim.

Table of Contents

1. nano — The Beginner-Friendly Editor
2. vim — The Power User Editor
3. When to Use Which
4. Exercises

nano — The Beginner-Friendly Editor

nano is the easiest terminal text editor. All keyboard shortcuts are shown at the bottom of the screen.

Open / create a file

nano myfile.txt

If the file doesn't exist, nano creates it when you save.

nano Interface

  GNU nano 6.2          myfile.txt

Hello World
This is my file content.
|  ← cursor is here



^G Help    ^O Write Out  ^W Where Is  ^K Cut       ^U Paste
^X Exit    ^R Read File  ^\ Replace   ^J Justify   ^T Spell

The ^ symbol means Ctrl. So ^O means Ctrl + O.

Essential nano shortcuts

Practical workflow

# 1. Open the file
nano config.txt

# 2. Type your content
# 3. Save: Ctrl + O, then Enter to confirm filename
# 4. Exit: Ctrl + X

Open file at a specific line

nano +15 config.txt    # opens at line 15

nano with syntax highlighting

# Open a Python file — nano highlights syntax automatically
nano script.py

nano with line numbers

nano -l myfile.txt

vim — The Power User Editor

vim is extremely powerful but has a learning curve. The key concept: vim has modes.

The Three Modes

┌─────────────┐
│ NORMAL MODE │ ← You start here. Navigate and execute commands.
│   (default) │
└──────┬──────┘
       │
       │ Press 'i' to enter Insert Mode
       │ Press ':' to enter Command Mode
       ▼
┌─────────────┐     ┌──────────────┐
│ INSERT MODE │     │ COMMAND MODE │
│  (editing)  │     │  (save/quit) │
└──────┬──────┘     └──────┬───────┘
       │                    │
       │ Press 'Esc'       │ Press 'Enter' to execute
       │ to go back        │ then back to Normal Mode
       └────────┬──────────┘
                │
                ▼
         Back to NORMAL

Open a file

vim myfile.txt

Survival guide: Save and Quit

If you accidentally open vim, here's how to get out:

1. Press  Esc          (make sure you're in Normal Mode)
2. Type   :wq          (write and quit)
3. Press  Enter

Other quit commands:

Normal Mode — Navigation

Normal Mode — Editing

Normal Mode — Search

Practical vim workflow

# Open file
vim server.conf

# 1. Press 'i' to enter Insert Mode
# 2. Type or edit your text
# 3. Press 'Esc' to return to Normal Mode
# 4. Type ':wq' and press Enter to save and quit

Open file at a specific line

vim +20 config.txt    # opens at line 20

vim with line numbers

In Normal Mode, type:

:set number

To make it permanent, add to ~/.vimrc:

echo "set number" >> ~/.vimrc

When to Use Which

Exercises

Exercise 1: nano basics

# 1. Create and edit a file with nano
nano grocery-list.txt

# 2. Type this content:
#    Milk
#    Bread
#    Eggs
#    Butter

# 3. Save: Ctrl + O, Enter
# 4. Exit: Ctrl + X

# 5. Verify
cat grocery-list.txt

Exercise 2: nano search and replace

# 1. Open the file
nano grocery-list.txt

# 2. Search: Ctrl + W, type "Bread", Enter
# 3. Replace: Ctrl + \, type "Bread", Enter, type "Whole Wheat Bread", Enter
# 4. Confirm: Y
# 5. Save and exit: Ctrl + O, Enter, Ctrl + X

Exercise 3: vim survival

# 1. Open a file in vim
vim practice.txt

# 2. Press 'i' to enter Insert Mode
# 3. Type: "I survived vim!"
# 4. Press 'Esc'
# 5. Type ':wq' and press Enter

# 6. Verify
cat practice.txt

Exercise 4: vim editing

# 1. Open the file
vim practice.txt

# 2. In Normal Mode:
#    - Press 'o' to open a new line below
#    - Type: "This is line 2"
#    - Press Esc
#    - Press 'yy' to copy the line
#    - Press 'p' to paste it below
#    - Press 'dd' to delete the duplicate
#    - Type ':wq' to save and quit

cat practice.txt

Key Takeaways

• nano — easy, visual shortcuts at the bottom, Ctrl+O save, Ctrl+X exit
• vim — modal editor, i to type, Esc to stop, :wq to save and quit
• Start with nano, learn vim gradually — it pays off enormously
• Esc is your safety key in vim — when in doubt, press Esc

Next Lesson: Lesson 5: Getting Help →