nano#

Concepts#

Why You Need a Terminal Text Editor#

Many Linux tasks require editing configuration files, scripts, or system files directly from the command line. You cannot always use a graphical editor — especially on servers without a desktop environment, over SSH, or when the desktop is broken.

The two most common terminal editors are nano (simple) and vim (powerful). This lesson covers nano.

What Is nano?#

nano is a straightforward, beginner-friendly terminal text editor. It is pre-installed on both Ubuntu and Debian. It shows a list of keyboard shortcuts at the bottom of the screen, so you do not need to memorize anything to get started.

Opening Files#

nano filename.txt              # open a file (creates it if it doesn't exist)
nano +15 filename.txt          # open and jump to line 15
nano -l filename.txt           # show line numbers
sudo nano /etc/hostname        # edit system files (requires sudo)

The nano Interface#

When you open a file, you see:

  GNU nano 7.2              filename.txt

This is the file content.
You type here directly.
The cursor blinks where text will be inserted.



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

Title bar (top) — shows the nano version and filename
Editing area (middle) — the file content
Shortcut bar (bottom) — keyboard shortcuts
^ means Ctrl. So ^O means Ctrl + O.
M- means Alt (Meta key). So M-U means Alt + U.

Essential Shortcuts#

File Operations#

Shortcut	Action
`Ctrl + O`	Save (Write Out). Press Enter to confirm the filename.
`Ctrl + X`	Exit. If unsaved changes exist, it asks to save first.
`Ctrl + R`	Read/Insert a file at cursor position

Shortcut	Action
Arrow keys	Move cursor
`Ctrl + A`	Go to beginning of line
`Ctrl + E`	Go to end of line
`Ctrl + Y`	Page up
`Ctrl + V`	Page down
`Ctrl + _` (underscore)	Go to a specific line number
`Alt + \`	Go to beginning of file
`Alt + /`	Go to end of file

Editing#

Shortcut	Action
`Ctrl + K`	Cut the current line (or selection)
`Ctrl + U`	Paste (Uncut) the last cut text
`Alt + 6`	Copy the current line (without cutting)
`Ctrl + Shift + K`	Delete the current line
`Alt + U`	Undo
`Alt + E`	Redo
`Alt + 3`	Toggle comment/uncomment (prefixes with `#`)

Search and Replace#

Shortcut	Action
`Ctrl + W`	Search (Where Is). Type the term and press Enter.
`Alt + W`	Search for next occurrence
`Ctrl + \`	Search and Replace

Selection#

Shortcut	Action
`Alt + A`	Start a selection (mark). Move cursor to expand selection.
`Ctrl + K`	Cut the selection
`Alt + 6`	Copy the selection
`Ctrl + ^` (`Ctrl + 6`)	Set mark (alternative)

Configuration: `~/.nanorc`#

You can customize nano’s behavior by creating or editing ~/.nanorc:

# Useful settings for ~/.nanorc

# Show line numbers
set linenumbers

# Enable mouse support
set mouse

# Use smooth scrolling
set smooth

# Set tab size to 4 spaces
set tabsize 4

# Convert tabs to spaces
set tabstospaces

# Enable auto-indentation
set autoindent

# Show cursor position in the status bar
set constantshow

# Enable syntax highlighting (usually enabled by default)
include "/usr/share/nano/*.nanorc"

Syntax Highlighting#

nano supports syntax highlighting for many languages. On both Ubuntu and Debian, highlighting files are in /usr/share/nano/. They are usually included by default. If not, add this to ~/.nanorc:

include "/usr/share/nano/*.nanorc"

Lab#

Exercise 1: Create and Edit a File#

# Open a new file
nano ~/lab_notes.txt

# Type the following text:
# This is my first nano edit.
# I am learning Linux.
# nano is simple and effective.

# Save: Ctrl+O, then Enter
# Exit: Ctrl+X

Exercise 2: Navigate a File#

# Open a long file to practice navigation
nano /etc/services

# Page down: Ctrl+V (several times)
# Page up: Ctrl+Y
# Go to line 100: Ctrl+_ then type 100 and Enter
# Go to beginning: Alt+\
# Go to end: Alt+/
# Exit without saving: Ctrl+X (press N if asked to save)

Exercise 3: Search and Replace#

# Open the file you created
nano ~/lab_notes.txt

# Search for "Linux": Ctrl+W, type "Linux", press Enter
# The cursor jumps to the match

# Search and Replace: Ctrl+\
# Search for: simple
# Replace with: straightforward
# Press Y to confirm (or A for all occurrences)

# Save and exit: Ctrl+O, Enter, Ctrl+X

Exercise 4: Cut, Copy, and Paste#

nano ~/lab_notes.txt

# Add a few more lines (type them in):
# Line four
# Line five
# Line six

# Cut a line: move to "Line five", press Ctrl+K
# (The line disappears — it's in the clipboard)

# Move to the end of the file
# Paste: Ctrl+U
# (Line five appears at the new location)

# Copy without cutting: move to a line, press Alt+6
# Move somewhere else and press Ctrl+U to paste

# Undo: Alt+U

# Save and exit

Exercise 5: Select a Block of Text#

nano ~/lab_notes.txt

# Place cursor at the beginning of a line
# Start selection: Alt+A
# Move cursor down 2 lines (the selected text is highlighted)
# Cut selection: Ctrl+K
# Move to a different line
# Paste: Ctrl+U

# Save and exit

Exercise 6: Configure nano#

# Create your nano configuration
nano ~/.nanorc

# Add these settings:
set linenumbers
set tabsize 4
set tabstospaces
set autoindent
set constantshow
include "/usr/share/nano/*.nanorc"

# Save and exit

# Now open a file — you should see line numbers and the cursor position
nano ~/lab_notes.txt
# Exit when done

Exercise 7: Edit a System File#

# Edit the hostname file (requires sudo)
sudo nano /etc/hostname

# Note the current hostname
# Do NOT change it — just observe
# Exit without saving: Ctrl+X

# View available syntax highlighting files
ls /usr/share/nano/

Clean Up#

rm ~/lab_notes.txt

Review#

1. How do you save a file in nano?

Ctrl + O (Write Out), then press Enter to confirm the filename.

2. How do you exit nano?

Ctrl + X. If there are unsaved changes, nano asks if you want to save (Y), discard (N), or cancel (Ctrl+C).

3. How do you search for text in nano?

Ctrl + W, type the search term, press Enter. Use Alt + W to find the next occurrence.

4. How do you undo an action in nano?

Alt + U for undo, Alt + E for redo.

5. What does `^` mean in nano's shortcut bar?

^ means the Ctrl key. So ^X means Ctrl + X and ^O means Ctrl + O.

6. How do you jump to a specific line number?

Ctrl + _ (Ctrl + underscore), type the line number, press Enter.

7. Where is nano's configuration file?

~/.nanorc (per-user) or /etc/nanorc (system-wide).

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