Linux
Linux Pipelines and File Operations: Composing Tools into Data Flows
A deep walk-through of the Unix pipeline model: stdin/stdout/stderr and file descriptors, every common redirection form, the grep/awk/sed/cut/sort/uniq/xargs toolchain, named pipes, and process substitution -- with …
Linux Process and Resource Management: From `top` to cgroups
How processes are born and die on Linux: the fork/exec model, the state machine that ps and top print in the STAT column, the resource axes (CPU, memory, disk I/O, network) that actually constrain a server, the signals …
Linux Service Management: systemd, systemctl, and journald
A working model of systemd: PID 1, units and targets, the service lifecycle, writing your own unit files, journalctl filtering, timers as a cron replacement, and a disciplined troubleshooting workflow.
Linux User Management: Users, Groups, sudo, and Security
A working mental model for Linux accounts: how /etc/passwd and /etc/shadow fit together, when to use a primary group versus a supplementary one, how sudo actually decides, and the full lifecycle of useradd / usermod / …
Linux Package Management: apt, dnf, pacman, and Building from Source
Master package management across distributions: dpkg/apt for Debian/Ubuntu, rpm/yum/dnf for RHEL/CentOS, pacman for Arch, dependency troubleshooting, version locking, mirrors, and compiling from source.
Linux Disk Management: Partitions, Filesystems, LVM, and the Mount Stack
End-to-end disk workflow on Linux: identify block devices with lsblk, partition with GPT, format with ext4 / xfs, mount persistently through /etc/fstab, expand capacity online with LVM, and debug the classic 'disk full …
Linux File Permissions: rwx, chmod, chown, and Beyond
Master the Linux permission model: rwx semantics on files vs directories, numeric and symbolic notation, chmod/chown usage, umask defaults, SUID/SGID/Sticky bit, and ACLs.
Linux Basics: Core Concepts and Essential Commands
Your entry guide to Linux: the multi-user permission model, the FHS directory tree, distribution lineages, and the command-line muscle memory you need before any deeper topic makes sense.