说明：  《UNIX培训教材》，主要介绍UNIX操作系统的系统结构与常用操作。包括UNIX操作系统、基本常识、UNIX文件系统、常用指令和Shell基本知识等
(UNIX training materials, introduces the system structure of the UNIX operating system and common operations. Including the UNIX operating system, basic knowledge of the UNIX file system commonly used commands and Shell basic knowledge, etc.)