This comprehensive guide walks you through Linux user and group concepts, UID/GID identifiers, essential commands like useradd, groupadd, id, passwd, and su/sudo, plus configuration files and security practices for effective system administration.
This guide explains Linux's multi‑user architecture, the meaning of UID/GID, how to view and edit /etc/passwd and /etc/shadow, and provides step‑by‑step commands for creating, modifying, and deleting users and groups, including su and sudo usage.
This article explains how Docker containers run processes as the host’s root user by default, how UID and GID are shared between host and container, demonstrates the security implications through demos with volume mounts, and shows how to change the container user via Dockerfile or the --user flag.
This article explains how Android inherits Linux's UID/GID based permission model, details the sandbox isolation for apps, describes how system and app processes obtain their UID/GID, and shows how adb shell and framework permissions grant extensive access to the device.
