Linux Overview and Core Concepts
Linux Overview and History
- Origins: Linux is a Unix-like operating system. It was inspired by Unix and designed to be a free and open-source alternative.
- Development: Created by Linus Torvalds in 1991. It uses many components from the GNU Project, which aimed to create a free Unix system.
Core Components of Linux
- Kernel: The core of the operating system. Manages hardware, memory, processes, and system calls.
- GNU Utilities: A collection of software tools (e.g., compilers, editors, and shell utilities) that complement the kernel.
- Shell (Bash): A command-line interface to interact with the system and run scripts.
- System Calls: Interface for applications to communicate with the kernel, e.g., opening files, creating processes.
Basic Linux Commands Demonstrated
echo – Prints text to the consoleman – Displays manual pages for commandstouch – Creates a new, empty filels – Lists files and directoriescat – Displays the contents of a filestat – Shows metadata about a filerm – Removes files> – Redirects output to a file (overwrite)< – Redirects input from a file| – Used to pipe output from one command to another
Additional Topics Covered
- Bash Scripting: Automates tasks using shell scripts, supports variables, loops, and conditionals.
- User Management: Handling user accounts, including managing root (superuser) privileges.
- File System Structure: Hierarchical structure starting from
/. Key directories: /home, /etc, /bin, /var, /usr.
- File Permissions: Permissions (read, write, execute) for user, group, and others. Managed using
chmod and viewed using ls -l.
- Process Management: Commands like
ps, top, kill to monitor and control processes.
Linux Distributions (Distros)
- Definition: Variants of Linux bundled with different software and package managers.
- Examples: Ubuntu, Fedora, Debian, Arch, CentOS.
- Differences: Include package management systems, default GUIs, and target audiences (newbie vs. advanced users).