Author: Chirag

Every file has owner, group, and other permissions for read, write, and execute. Master this and you stop fighting “permission denied.”

Root can do anything. sudo lets you do root things temporarily, with a log. Knowing the difference protects your system.

Combining small commands with | and > is what makes the shell a real programming environment. Learn this once and you write fewer scripts.

Three ways to find out what any Linux command does, without leaving the terminal. The skill that makes you self-sufficient.

Variables your shell and every program inherit. Configure tools, point to credentials, set locale — all without editing config files.

When you type ls, the shell searches a list of directories called PATH to find the binary. Master PATH and you control your environment.

Nano shows its commands at the bottom of the screen. You can be productive in 60 seconds. Perfect for SSH config edits.

Vim is hard for a week and second nature for a decade. The shortcut is to learn 20 commands well, not 200 commands badly.

The five stages: firmware, bootloader, kernel, init, login. Knowing the chain lets you fix boot problems instead of reinstalling.

Arch ships almost nothing by default — you build the system from the base up. Hardest to install, most you will learn from a single distro.