LWM-Linux/01 - Introduction to Linux/Linux Command Line Interface (CLI).md

1. Introduction to the Linux CLI

• What is the CLI?
• Why use CLI over GUI?
• Accessing the terminal

2. Basic CLI Navigation and File Management

• pwd (print working directory)
• ls (list directory contents)
• cd (change directory)
• mkdir (make directory)
• touch (create empty file)
• cp (copy)
• mv (move/rename)
• rm (remove)

3. Viewing and Editing Files

• cat (concatenate and display file content)
• less (view file contents page by page)
• head and tail (view beginning or end of file)
• nano and vim (text editors)

4. File Permissions and Ownership

• chmod (change file permissions)
• chown (change file ownership)
• Understanding permission notation (rwx)

5. Process Management

• ps (list processes)
• top (dynamic process viewer)
• kill (terminate processes)
• jobs, bg, and fg (background and foreground processes)

6. System Information and Management

• uname (system information)
• df (disk space usage)
• du (directory space usage)
• free (memory usage)
• shutdown and reboot

7. Package Management

• apt (Debian/Ubuntu)
• yum (Red Hat/CentOS)
• pacman (Arch Linux)

8. Networking

• ifconfig / ip (network interface configuration)
• ping (test network connectivity)
• ssh (secure shell)
• scp (secure copy)
• wget (download files)

9. Text Processing and Searching

• grep (search for patterns in files)
• sed (stream editor for filtering and transforming text)
• awk (pattern scanning and text processing)
• find (search for files and directories)

10. Piping and Redirection

• | (pipe operator)
• > and >> (output redirection)
• < (input redirection)

11. Shell Scripting Basics

• Creating and running shell scripts
• Variables and environment variables
• Conditional statements (if, else, elif)
• Loops (for, while)

12. Advanced CLI Features

• Command history and shortcuts
• Tab completion
• Aliases
• Regular expressions

13. System Logs and Troubleshooting

• journalctl (view system logs)
• dmesg (display kernel messages)
• lsof (list open files)

Superuser Powers:

• Some tasks require administrator privileges. To execute commands as the superuser (root), prefix them with sudo.
• Be cautious with superuser access—it's powerful and WILL break your machine if used improperly!!!