Linux Fundamentals
The shell, the filesystem, processes, and permissions — everything a terminal-first engineer leans on every day.
The History of Linux
From Unix at Bell Labs to the kernel that runs the cloud, decade by decade.
Getting Started with Linux
What Linux is, the shell, and your first commands.
Filesystem Navigation
Move around the filesystem with
pwd,ls, andcd.Creating and Manipulating Files
touch, mkdir, cp, mv, rm - the core file operations.
Pipes and Redirection
Chain commands with pipes, and send output to files with > and >>.
Environment Variables and PATH
Read and set variables with $VAR, export, and understand PATH.
Getting Help: man, help, and Reading Docs
man pages, --help, apropos, and the habit of looking things up instead of memorizing them.
Users and Permissions
Understand users, groups, and the chmod / chown commands.
Text Processing with grep, sed, and awk
Search, transform, and extract fields from text on the command line.
Finding Files with find and xargs
Locate files by name or pattern, then act on all of them at once.
Processes and the System
ps, top, kill, and how to find what is running.
Archives and Compression
Bundle files with tar, and shrink them with gzip.
Package Management
Install, remove, and search for software with apt.
Shell Scripting Basics
Turn a sequence of commands into a reusable script: variables, conditionals, loops, and functions.
Networking Basics
How Linux machines talk to each other: ping, curl, wget, ssh, and interfaces.
Job Scheduling
Run commands automatically with cron, at, and their modern systemd-timer replacement.
Disks and Filesystems
Block devices, partitions, mount points, df vs du, inodes, and hard vs symbolic links.
Vim Editor Mastery
Modes, motions, and the editing workflow behind the editor on almost every Linux box.
Regular Expressions
Anchors, character classes, quantifiers, and alternation - pattern matching with grep and sed.
systemd and Services
How modern Linux starts, supervises, and logs background services with systemctl.
Linux Security Basics
sudo, least privilege, SSH keys, and the habits that keep a server from getting hacked.
Advanced Networking & Diagnostics
Reading netstat/ss output, DNS with dig, and tracing a route hop by hop.
Process Signals & Job Control
What kill actually sends, the signals worth knowing, and running work in the background.
Firewalls & Network Security
Default-deny thinking, ufw in practice, and how it relates to iptables underneath.
The Linux Boot Process & Kernel
From power-on to a login prompt: firmware, bootloader, kernel, initramfs, and PID 1.
Containers From First Principles
The kernel features - namespaces and cgroups - that Docker and Kubernetes are built on.
Performance Troubleshooting
Reading load average, top, and vmstat to find whether CPU, memory, or I/O is the bottleneck.