🔹What is Linux?

Linux is an open-source operating system that serves as the foundation for many computer systems. It provides a powerful and reliable environment for running applications and managing resources. Here's a brief explanation of Linux in simple terms:

1. Operating System: Linux is like the brain of a computer. It manages all the hardware, software, and user interactions. It ensures that different programs can run smoothly and efficiently.

2. Free and Open-Source: Linux is free to use and open-source, which means its source code is accessible to anyone. This encourages collaboration and innovation, as developers worldwide contribute to its improvement.

3. Stability and Security: Linux is known for its stability and security features. It is less prone to crashes and malware attacks compared to other operating systems. This makes it a popular choice for servers and critical systems.

4. Customization: Linux offers great flexibility and customization options. Users can choose from various desktop environments (such as GNOME, KDE, or XFCE) to personalize their user interface. They can also customize system settings and appearance according to their preferences.

5. Terminal and Command-Line Interface: Linux provides a powerful command-line interface (CLI), also known as the terminal or shell. With commands, users can perform tasks efficiently and automate processes. The CLI offers greater control and advanced features for experienced users.

6. Software Repository: Linux distributions come with a software repository that contains a vast collection of applications. Users can easily install and update software using package managers, making it convenient to discover and use new programs.

7. Compatibility: Linux supports a wide range of hardware architectures, making it compatible with various devices and systems. It runs on desktops, laptops, servers, mobile devices, embedded systems, and even supercomputers.

8. Community and Support: Linux has a large and active community of developers and users who collaborate, share knowledge, and provide support. Online forums, documentation, and tutorials are available to help users troubleshoot issues and learn more about Linux.

🔹Linux Commands

Here is a list of commonly used Linux commands along with a brief explanation of their functionalities:

1. ls: Lists the files and directories in the current directory.

2. cd: Changes the current directory.

3. pwd: Prints the current working directory.

4. mkdir: Creates a new directory.

5. rm: Removes files and directories.

6. cp: Copies files and directories.

7. mv: Moves or renames files and directories.

8. cat: Concatenates and displays the contents of files.

9. grep: Searches for patterns in files.

10. chmod: Changes the permissions of files and directories.

11. chown: Changes the ownership of files and directories.

12. sudo: Executes a command with administrative privileges.

13. apt-get or yum: Package managers used to install, update, and manage software packages.

14. wget: Downloads files from the internet.

15. ssh: Connects to a remote server securely using the SSH protocol.

16. tar: Archives and extracts files.

17. top: Displays real-time information about system processes and resource usage.

18. df: Shows the disk space usage of file systems.

19. free: Displays the amount of free and used memory in the system.

20. history: Lists the previously executed commands.

21. man: Displays the manual pages for commands and provides information on their usage and options.

22. find: Searches for files and directories based on various criteria, such as name, type, size, or permissions.

23. grep: Searches for specific patterns or regular expressions within files.

24. head: Displays the first few lines of a file.

25. tail: Displays the last few lines of a file.

26. sort: Sorts the contents of a file or input.

27. uniq: Filters adjacent duplicate lines from input.

28. wc: Counts the number of lines, words, and characters in a file or input.

29. sed: Stream editor for modifying and transforming text.

30. awk: Powerful text processing tool for manipulating structured data.

31. ping: Sends network ICMP echo requests to a specific host to check connectivity.

32. ifconfig or ip: Displays network interface configuration and manages network settings.

33. netstat: Shows network statistics, active connections, and listening ports.

34. ssh-keygen: Generates SSH key pairs for secure authentication.

35. tar: Archives files into a single file, often compressed.

36. curl: Command-line tool for transferring data using various protocols (HTTP, FTP, etc.).

37. du: Displays disk usage of files and directories.

38. cron: Schedules recurring tasks or commands to run automatically at specified intervals.

39. alias: Creates custom shortcuts or aliases for commands.

40. echo: Prints text or variables to the terminal.

41. nano filename: Opens the Nano text editor and creates or opens the specified file.

    Ctrl + O: Saves the current file.

    Ctrl + X: Exits the Nano editor.

    Ctrl + G: Opens the Nano help menu, displaying available commands.

    Ctrl + K: Cuts the current line and stores it in the Nano clipboard.

    Ctrl + U: Pastes the contents of the Nano clipboard.

    Ctrl + W: Searches for a specific string within the file.

Task: What is the linux command to

1. Check your present working directory.

   

2. List all the files or directories including hidden files.

   

3. Create a nested directory A/B/C/D/E