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Linux Basics

This document introduces basic Linux operations that you will frequently use when working with HemiHex edge devices and Jetson-based systems.

1. Terminal​

The terminal is a command-line interface used to interact with the operating system.

1.1. Open the terminal​

On Ubuntu you can open the terminal by:

  • Pressing the keyboard shortcut: Ctrl + Alt + T
  • Or opening Terminal from the application menu

Open terminal shortcut Open terminal from menu

1.2. Basic commands​

View the current directory

Display the full path of the current working directory:

pwd

List files/directories

List files and subdirectories in the current directory:

ls

Create a new directory

Create a directory named File_demo:

mkdir File_demo

Change directory

Enter the File_demo directory:

cd File_demo

Return to parent directory

Go back to the parent directory:

cd ..

Create new file

Create a file named Version.txt:

touch Version.txt

Modify file

Append the text System Information to Version.txt:

echo "System Information" >> Version.txt

View file

Display the contents of Version.txt:

cat Version.txt

Delete directory

Delete the File_demo directory and everything inside it:

rm -rf File_demo

⚠️ Warning
rm -rf permanently deletes files/directories. Double‑check the path before running it.

File operations in terminal

1.3. Shortcut keys​

Some useful terminal shortcuts:

Ctrl + C
Interrupt (terminate) the currently running command.

Ctrl + Z
Suspend the current process (puts it in the background as a stopped job).

Tab
Auto‑complete file names and commands.
Press twice to list all possible completions.

2. Text editors​

Linux provides multiple text editors. You will use them to edit configuration files, scripts, and logs.

2.1. Gedit (easy – graphical)​

Gedit is the default text editor in the GNOME desktop environment. It has a graphical interface and is suitable for beginners.

Open a file with Gedit

gedit Version.txt

This will open Version.txt in a window where you can edit and save it.

Gedit editor

2.2. Nano (medium – terminal editor)​

Nano is a simple, easy‑to‑use text editor that runs inside the terminal. It is a good choice when you are connected via SSH or don’t have a desktop environment.

Install Nano (if not already installed)

sudo apt update
sudo apt install nano -y

Open a file with Nano

nano Version.txt

At the bottom of the Nano window you’ll see common shortcuts. Some useful ones:

  • Ctrl + X – Exit Nano (will ask to save if there are changes)
  • Ctrl + O – Write (save) the file
  • Ctrl + W – Search for text
  • Ctrl + K – Cut the current line
  • Ctrl + U – Paste the last cut text

Nano editor

2.3. Vi/Vim (advanced – powerful terminal editor)​

Vim is an enhanced version of the classic vi editor. It is extremely powerful and is available on almost all Unix and Linux systems.

Open a file with Vi/Vim

vi Version.txt

Modes​

Vim has three main modes:

  • Normal (command) mode – default mode when Vim starts
  • Insert mode – for typing and editing text
  • Last-line (command-line) mode – for commands like save and quit

Basic mode switching:

  • Press i in normal mode to enter insert mode
  • Press Esc to return to normal mode
  • Press : in normal mode to enter last-line mode (command-line at the bottom)

Save and exit commands (from last-line mode)​

Type these after pressing : in normal mode:

  • :w – Save the file
  • :q – Quit Vim
  • :wq – Save and quit
  • :q! – Quit without saving

Vim editor

This page is intended as a quick Linux reference for HemiHex Jetson/edge deployments. You can link to it from other docs wherever basic terminal or editor usage is required.