Documentation / Users, Permissions & ACLs

2.1 User and Group Management

DAC model, special bits (SUID, SGID, Sticky Bit), sudoers, and POSIX access control lists.

2.1 User and Group Management

Linux handles local authentication through /etc/passwd, /etc/shadow, and /etc/group.

# Create an unprivileged system daemon user without interactive shell
useradd -r -s /usr/sbin/nologin -d /var/lib/myapp -c "MyApp Service User" myapp
# Inspect UID, GID, and supplemental groups
id myapp