Complete guide to Linux commands: learn to master the most powerful operating system

Introduction

Linux is a powerful and flexible operating system, with a wide variety of commands for managing and interacting with the system. Knowing Linux commands allows you to perform a variety of tasks, such as manipulating files, creating scripts, managing processes, and much more.

Navigate directories

To move between directories use the cd command. For example, to get into the "My Documents" directory, run:

cd Documenti

To go back to the previous directory, use the cd.. command:

cd..

Create and remove directories

To create a new directory, use the mkdir command. For example, to create a directory called "new_folder", run:

mkdir nuova_cartella

To remove an empty directory, use the rmdir command. For example, to remove the directory called "new_folder", run:

rmdir nuova_cartella

To remove a directory and its contents, use the rm -r command. Note that this command irreversibly removes files and subdirectories within the directory. For example, to remove the directory called "old_folder" and all of its contents, run:

rm -r vecchia_cartella

View the contents of a directory

The ls command is used to view the contents of a directory. The basic form of the command returns the names of files and subdirectories within the current directory:

ls

To also view file details, such as permissions, size, and modification dates, use the -l option:

ls -l

To display all files, including hidden ones (starting with a dot), use the -a option:

ls -a

Change file permissions

The chmod command is used to change file access permissions. You can specify permissions as a combination of owner, group and others, using the following letters and symbols:

• r: reading
• w: writing
• x: run
• -: without permission

For example, to grant the owner read and write permission on a file called "my_file", run:

chmod u+rw mio_file

To give all users read permission on the same file, run:

chmod a+r mio_file

To remove write permission from group members, run:

chmod gw mio_file

Manage processes

The ps command is used to list the processes running on the system. The basic form of the command returns a list of processes related to the current user:

ps

To view all processes in the system, use the -e option:

ps -e

To kill a running process, use the kill command. You can specify the process to terminate using its ID or name. For example, to terminate a process with ID 1234, run:

kill 1234

To kill a process using its name, use the killall command. For example, to kill all processes named "example", run:

killall esempio

Manage files

The cp command is used to copy a file from one location to another. For example, to copy a file named "my_file" from the current directory to the "My Documents" directory, run:

cp mio_file Documenti/

To move a file instead of copying it, use the mv command. For example, to move the file "my_file" from the current directory to the "My Documents" directory, run:

mv mio_file Documenti/

To rename a file, use the mv command to move the renamed file into the same directory. For example, to rename the file "old_name" to "new_name", run:

mv vecchio_nome nuovo_nome

To delete a file, use the rm command. For example, to delete the file "un_file", run:

rm un_file

Manage the network

The ifconfig command is used to display information about the system's network configuration. Returns information such as IP address, default gateway, MAC address and much more. Here's how you can use it:

ifconfig

To enable or disable a network interface, use the ifup or ifdown command. For example, to enable the "eth0" network interface, run:

sudo ifup eth0

To disable the "eth0" network interface, run:

sudo ifdown eth0

Using the blockchain

Blockchain is a technology that allows for the creation and management of shared digital ledgers. There are various commands and tools for working with the blockchain, depending on the specific platform. For example, to interact with an Ethereum blockchain network, you can use the geth command or a graphical user interface such as MetaMask.

To install the geth client on Ubuntu, run:

sudo apt-get install geth

Then, to start the geth node and connect to the Ethereum network, run:

geth

If you're using a graphical user interface like MetaMask, follow the specific instructions for installing and using it.

Conclusion

In this tutorial, you learned some of the basic commands for mastering Linux. These commands will help you navigate directories, create and remove directories, view directory contents, change file permissions, manage processes, manage files, manage network, and use the blockchain. Experiment with these commands and continue to expand your knowledge to become a Linux operating system expert.