Linux Basics

1. Terminal

Terminal is a command line interface used to interact with the operating system.

1.1. Open the terminal

In Ubuntu, you can open it by using the shortcut keys Ctrl + Alt + T or by finding the terminal in the application 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:

xxxxxxxxxx
ls

Create a new directory

Create the File_demo directory:

xxxxxxxxxx
mkdir File_demo

Change directory

Enter File_demo directory:

xxxxxxxxxx
cd File_demo

Return to parent directory

xxxxxxxxxx
cd ..

Create new file

Create Version.txt file:

xxxxxxxxxx
touch Version.txt

Modify file

Add System Information to Version.txt file:

xxxxxxxxxx
echo "System Information" >> Version.txt

View file

View Version.txt file content:

xxxxxxxxxx
cat Version.txt

Delete directory

Delete File_demo directory:

xxxxxxxxxx
rm -rf File_demo

1.3. Shortcut keys

Ctrl + C

Terminate the currently running command

Ctrl + Z

Suspend the current process

Tab

Automatically complete the file name or command

2. Text editor

2.1. Gedit (Easy)

The default text editor in the GNOME desktop environment, with a graphical user interface (GUI).

Open file

xxxxxxxxxx
gedit Version.txt

2.2, Nano (Medium)

Simple and easy-to-use command line text editor, suitable for beginners.

Install

xxxxxxxxxx
sudo apt update
sudo apt install nano -y

Open file

xxxxxxxxxx
nano Version.txt

Ctrl + X: Exit (if there are unsaved changes, you will be prompted to save)

Ctrl + U: Paste clipboard contents

Ctrl + W: Search text

2.3, Vi/Vim (difficult)

Vim is an enhanced version of Vi editor, suitable for almost all Unix and Linux systems.

Open file

xxxxxxxxxx
vi Version.txt

Mode

Command mode: default state

Insert mode: press i to enter, press ESC to exit command mode

Last line mode: enter : in command mode, press ESC to exit command mode

Save/Exit

Last line mode

:w: Save file

:q: Exit

:wq: Save and exit

:q!: Force exit without saving