Recent Posts
Linux Tutorial / Understand systemd Services, Boot, and Logs
Understand Linux boot stages and systemd units, distinguish active services from boot enablement, and inspect current-boot logs with systemctl and journalctl.
Linux Tutorial / Install and Update Packages with APT and DNF
Compare APT on Debian or Ubuntu with DNF on Rocky Linux for searching, installing, updating, and removing packages, including repository and transaction checks.
Linux Tutorial / Inspect, Pause, and Stop Processes
Inspect Linux processes with ps, top, and pgrep, then safely pause, resume, and terminate a practice process while distinguishing shell jobs from services.
Linux Tutorial / File Permissions and Safe sudo Use
Learn to read file and directory permissions, practice chmod safely, and understand when to use sudo and how to diagnose access errors.
Linux Tutorial / Understand Users, Groups, and File Ownership
Understand UIDs, GIDs, primary and supplementary groups, and file ownership, then inspect them safely with id, groups, getent, ls, and stat.
Linux Tutorial / How the Shell Runs Commands: ;, &&, ||, Aliases, and Environment Variables
Learn how Bash resolves commands and uses exit status with ;, &&, and ||, then distinguish aliases, shell variables, and exported environment variables.
Linux Tutorial / Standard Input, Output, Redirection, and Pipes
Understand standard input, output, and error; practice file redirection and pipes; and learn why overwrite risk and redirection order matter.
Linux Tutorial / Compare Files with diff and cmp
Use diff and cmp to compare two files, read unified diff output, and distinguish a detected difference from an actual command error.
Linux Tutorial / Search and Process Text with grep, sort, uniq, cut, and wc
Practice searching, sorting, grouping, extracting, and counting text with grep, sort, uniq, cut, and wc, including reproducible output and key caveats.
Linux Tutorial / PID and PPID Explained: Find and Manage Processes
Understand what PID and PPID mean, inspect parent-child process relationships with ps and pgrep, and safely terminate a process you started yourself.