↩ 🔵 🔵 🔵 ❪✺❫ Operating System Concepts ○ Unix ○˒ ❪✺❫ GNU Concepts ○ ❪✺❫ Linux Concepts ○ ❪✺₁❫ Unix Classes ○ ❪✺₃❫ Unix Particulars ○ Unix Filesystem ○