Tag
linux
Published articles tagged linux.
A short history of Unix and Linux
Unix began as a research operating system at Bell Labs and grew into a family of standards and kernels. This overview traces BSD and GNU, the 1991 Linux kernel, the GPL, how distributions bundle the stack, and where Linux runs today—from servers to Android.
Booting Linux and systemd
From firmware to login, boot is a chain of loaders, an initial RAM disk, and PID 1. This overview covers UEFI and GRUB, initramfs, systemd units and targets, journald, and how Debian differs from older init and macOS launchd at a glance.
Graphical desktops on Linux
Linux graphics stack from kernel modesetting through compositors and toolkits to desktop environments. This overview compares X11 and Wayland, GNOME and KDE on Debian, display managers, and GTK versus Qt.
Hardware and devices in Linux
Drivers, firmware, and device nodes connect the kernel to hardware. This overview explains /dev, udev, block devices and partitions, firmware on Debian, and how USB and PCI devices appear on a running system.
Linux cheat sheet
Scannable commands for systemd, journals, files, processes, packages, users, and networking on Debian—grouped for quick lookup beside the Linux operating system series.
Linux distributions and Debian
A distribution turns the Linux kernel into an installable system with policies, packages, and support timelines. This overview explains what distros add, how Debian's stable, testing, and unstable branches work, common derivatives, and how other families compare when you choose a base.
Linux filesystems
Paths, inodes, and mount points organize storage on Linux. This overview covers the Filesystem Hierarchy Standard, hard and symbolic links, common on-disk formats, /etc/fstab, virtual filesystems like /proc and /sys, and swap.
Linux glossary
Terms for the Linux operating system series—kernel, distribution, systemd, inode, namespace, and more—each defined briefly and linked to the chapter that goes deeper.
Linux on Windows, WSL, containers, and VMs
Linux runs on bare metal, inside VMs, in containers on a shared kernel, and on Windows via WSL2. This overview compares isolation and use cases and points to Docker and security chapters elsewhere in the knowledgebase.
Linux security primitives
Beyond file modes, Linux isolates and constrains processes with capabilities, namespaces, cgroups, seccomp, and mandatory access control. This overview explains AppArmor on Debian, SELinux elsewhere, and how containers combine these kernel features.
Networking on Linux
Sockets and routing are universal; Linux adds interface naming, iproute2, distro-specific network management, systemd-resolved, and netfilter. This overview focuses on the host stack on Debian and points to protocol detail elsewhere in the knowledgebase.
Package management on Debian
Debian ships software as signed .deb packages installed and upgraded with dpkg and APT. This overview covers repositories, suite components, deb822 sources, backports, pinning, security updates, and Flatpak and Snap beside the system package set.
Processes and inter-process communication
Programs run as processes created by fork and exec, coordinated with signals and IPC. This overview covers the process tree, states, pipes, sockets, shared memory, and D-Bus on Linux—with links to shell and Node boundaries covered elsewhere in the knowledgebase.
Scheduling tasks with cron and systemd timers
Linux runs recurring and one-shot jobs through several schedulers. This overview compares cron and crontab syntax, anacron, systemd timers, and at, and explains when each fits on a typical Debian server or desktop.
Terminals and shells in Linux
A terminal is a character device; a shell is a program that interprets commands. This overview covers TTYs, PTYs, virtual consoles, terminal emulators, login versus interactive shells, dash as /bin/sh, and where Bash scripting is documented separately.
The Linux kernel
The kernel is the privileged core that talks to hardware and exposes system calls to programs. This overview separates kernel space from user space, explains monolithic design and loadable modules, and covers scheduling, memory, versions, and how Debian ships kernel packages.
Users, groups and permissions in Linux
Every process runs as a user with group memberships and file mode bits. This overview covers UIDs and GIDs, passwd and shadow, rwx and umask, special bits, ACLs, sudo, and PAM on Debian.
Docker networking
Docker connects containers with bridge networks, veth pairs, and drivers. This page covers compose-style networking; the Linux host stack—iproute2, nftables, and interface naming—is in the Linux networking chapter.
Docker overview
Docker packages applications as images and runs them as isolated containers on a shared Linux kernel. This overview covers terminology and workflows; namespaces, cgroups, and when to prefer VMs are in the Linux OS series.
Shellscripting with Bash
Bash scripts glue commands together with variables, tests, and pipelines. This article is the language and scripting reference; for TTYs, login shells, and why /bin/sh is dash on Debian, see the Linux series terminals chapter.